Salivary Gland Adenocarcinoma (Salivary Gland Cancer) in Dogs
- Occurrence: very rare
- Location of illness: Head/Neck
Salivary gland adenocarcinoma in dogs is a malignantMalignant means "cancerous" and is used to describe tumors or neoplasms that grow invasively and have the ability to metastasize. Malignant tumors can cause serious health problems in dogs and cats. tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. that originates from the secretory epithelial cellsEpithelial cells are the cells that make up epithelial tissue. They line the outer surfaces of the body, as well as internal cavities, ducts, and organs, and perform functions such as protection, absorption, secretion, and filtration. of the salivary glands. This rare form of tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. accounts for less than 1% of all canineCanine refers to anything related to dogs. The term is used to describe characteristics, diseases, or specific aspects that specifically affect dogs. neoplasms but presents a particular diagnostic and therapeutic challenge. Primarily affected are the large salivary glands such as the Glandula mandibularis (mandibular glandThe mandibular gland is one of the salivary glands located near the mandible (lower jaw). It plays an important role in producing saliva to moisten food and aid digestion.), Glandula parotis (parotid gland), and Glandula sublingualis (sublingual gland). Histopathologically, these are tumors with a glandular (adenoid) growth pattern and varying degrees of differentiation.
The most important facts at a glance
Salivary gland adenocarcinoma is a rare but clinically significant tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. disease in dogs. The disease predominantly affects older animals and typically manifests as a slowly growing swelling in the area of the large salivary glands. The etiologyEtiology is the study of the causes and origins of diseases. It deals with the factors that contribute to the emergence and development of pathological conditions. is multifactorialMultifactorial refers to conditions or diseases that arise from the interplay of several causes or risk factors. In dogs and cats, these can be genetic predispositions, environmental influences, and nutritional factors that together lead to health problems., with genetic alterations and chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. inflammatory processes being discussed as potential risk factors.
DiagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. requires a multimodal approach consisting of clinical examination, advanced imaging, and histopathologicalHistopathological refers to the microscopic examination of tissue samples for the diagnosis of diseases. This technique is used to identify the specific characteristics of diseases at the cellular level in dogs and cats. confirmation. TherapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. is based on wide surgical resection, often supplemented by adjuvant radiation therapyRadiation therapy is the use of radiation, most often to treat cancer. It can be used to kill cancer cells or slow their growth without significantly damaging surrounding healthy tissue. and, in selected cases, by chemotherapyChemotherapy refers to the treatment of diseases, especially cancer, with chemical substances or drugs. It aims to kill cancer cells or prevent their growth, but can also affect healthy cells.. Newer therapeutic approaches such as targeted molecular therapies and immunotherapy are in clinical evaluation and could expand the treatment spectrum in the future.
The prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. is significantly determined by the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. stage, the completeness of surgical resection, and the presence of metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body.. Early diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and multimodal therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. can significantly improve the survival time and quality of life of affected dogs. Close follow-up is essential to detect recurrences or metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body. early and intervene accordingly.
Causes
The disease occurs predominantly in older dogs, with a medianMedian refers to the midline or center of the body or an organ. In veterinary medicine, the term can be used to describe the location of a structure in relation to the center of the body. age of approximately 10–12 years. Although there is no clear gender predispositionA predisposition is an innate inclination or susceptibility of an organism to certain diseases or conditions. In dogs and cats, there may be a genetic predisposition to certain conditions such as hip dysplasia or certain heart diseases., some studies report a slightly increased incidenceIncidence refers to the number of new cases of a disease or condition that occur within a specific time period in a specific population group. It provides information about the risk of contracting the disease. in male animals. The biological behavior of these tumors is characterized by local invasiveness and a high potential for metastasisA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body., which significantly influences the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop.. The exact causes for the development of salivary gland adenocarcinomas are not fully understood. Genetic predispositions, environmental factors, or a combination of both could play a role.
- Genetic predispositionA predisposition is an innate inclination or susceptibility of an organism to certain diseases or conditions. In dogs and cats, there may be a genetic predisposition to certain conditions such as hip dysplasia or certain heart diseases.: So far, no clear hereditary predispositions for salivary gland adenocarcinomas have been described. However, individual studies discuss mutations in oncogenic signaling pathways (e.g., EGFR or RAS pathway).
- Environmental factors and inflammatory conditions: ChronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. inflammatory conditions (sialadenitis) could contribute to degeneration. Concrete external risk factors have so far only been insufficiently investigated.
- Breed aspects: Since salivary gland tumors are rare, there is no clear accumulation in certain breeds. Larger dogs (e.g., German Shepherds, Labradors) are mentioned more frequently in some case reports, but the data basis is limited.
Supplements
The etiologyEtiology is the study of the causes and origins of diseases. It deals with the factors that contribute to the emergence and development of pathological conditions. of canineCanine refers to anything related to dogs. The term is used to describe characteristics, diseases, or specific aspects that specifically affect dogs. salivary gland adenocarcinoma is multifactorialMultifactorial refers to conditions or diseases that arise from the interplay of several causes or risk factors. In dogs and cats, these can be genetic predispositions, environmental influences, and nutritional factors that together lead to health problems. and not yet fully understood. Current research suggests a complex interplay of genetic and environmental factors:
Molecular genetic studies have identified alterations in various signaling pathways, including mutations in the EGFR (Epidermal Growth Factor Receptor) and RAS pathway. These changes lead to a dysregulation of cell growth and cell differentiation. Newer studies also point to epigenetic modifications that can influence gene expression without altering the DNADNA (deoxyribonucleic acid) is the molecule that carries the genetic instructions for the development, function, and reproduction of all known living organisms and many viruses. It is located in the cells of an organism and contains the information for heredity. sequence itself.
ChronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. inflammatory processes (sialadenitis) are discussed as possible risk factors, as they can lead to DNADNA (deoxyribonucleic acid) is the molecule that carries the genetic instructions for the development, function, and reproduction of all known living organisms and many viruses. It is located in the cells of an organism and contains the information for heredity. damage and cellularCellular refers to cells or consisting of cells. In biology and medicine, it refers to processes, structures, or functions that occur at the level of individual cells. transformation over a long period of time. ExposureExposure refers to the Contact with or subjection to certain substances, environmental factors, or pathogens. In veterinary medicine, this can include Contact with toxins, allergens, or infectious agents that can cause health problems in dogs and cats. to certain environmental toxins could also play a role, although concrete evidence for this is still lacking.
Although no clear breed predispositions have been established, larger dog breeds such as German Shepherds, Labrador Retrievers, and Golden Retrievers have been more frequently associated with this disease in some epidemiological surveys. However, these observations are based on limited data and require further validation by larger study populations.
Symptoms
The clinical presentation of salivary gland adenocarcinoma in dogs is variable and depends largely on the affected salivary gland, the tumor size, and the degree of invasion. The following symptoms may occur:
The most characteristic sign is a slowly growing, firm swelling in the area of the affected salivary gland, typically in the angle of the mandible or below the ear. This swelling may initially be painless, leading to a delayed diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients.. With increasing tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. growth, difficulty swallowing (dysphagiaDysphagia is the medical term for difficulty swallowing. In dogs and cats, dysphagia can be caused by diseases of the mouth, pharynx, or esophagus and impair the animal’s ability to eat.) can occur, which manifests as altered eating behavior and weight loss.
Increased salivation (hypersalivation) is a common symptom caused by mechanical irritation or obstructionobstruction refers to the blockage or narrowing of a hollow organ or canal, which hinders the normal flow of liquids or gases. In dogs and cats, an obstruction can occur in the digestive tract, airways, or urinary tract and often requires immediate medical treatment. of the salivary ducts. In advanced tumors, an unpleasant smelling bad breath (Foetor ex ore) may occur, especially if secondary infections or tissue necrosisNecrosis is the Death of tissue in a living organism, caused by factors such as injury, infection, or lack of blood supply. Necrotic tissue can cause Inflammatory conditions and further health problems. are present.
Infiltrative growth into adjacent structures can lead to neurological symptoms, including facial paralysisParalysis is the complete loss of muscle activity in one or more areas of the body, which can lead to immobility and loss of sensation. Paralysis can be caused by injuries, illnesses, or disorders of the nervous system. with involvement of the facial nerve or voice changes with laryngeal involvement. In tumors of the zygomatic gland, exophthalmos (protrusion of the eyeball) may be observed. Systemic symptoms such as lethargy, inappetence, and fever typically occur only in the advanced stage and may indicate metastasisA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body. or paraneoplastic syndromes.
Diagnosis
- Clinical examination: Typical signs are swelling in the neck or jaw area, difficulty swallowing (dysphagiaDysphagia is the medical term for difficulty swallowing. In dogs and cats, dysphagia can be caused by diseases of the mouth, pharynx, or esophagus and impair the animal's ability to eat.), or increased salivation. Dogs may also show apathyApathy refers to a state of indifference and reduced interest or lack of emotional involvement in activities or events that would normally arouse interest., loss of appetite, or pain.
- Imaging procedures: UltrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow., X-rayX-ray is an imaging technique that uses X-rays to create images of the inside of the body. It is often used to diagnose bone fractures, lung diseases, and other conditions., or CT/MRI to localize the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. and search for metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body. (especially lymph nodes, lungs).
- Fine needle aspiration/biopsy: A cytological or histological examination is necessary to confirm the adenocarcinoma with certainty. Modern molecular biological tests (e.g., immunohistochemistryImmunohistochemistry is a laboratory technique that uses antibodies to identify and localize specific antigens in tissue sections. This method is used in veterinary diagnostics to detect and characterize diseases at the cellular level in dogs and cats.) can reveal further prognostic markers.
The diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. of salivary gland adenocarcinoma requires a multimodal approach that combines clinical examination, imaging procedures, and histopathologicalHistopathological refers to the microscopic examination of tissue samples for the diagnosis of diseases. This technique is used to identify the specific characteristics of diseases at the cellular level in dogs and cats. confirmation:
The initialInitial means beginning or at the start. In medicine, it can refer to the first symptoms of a disease or the first phase of a treatment process. clinical examination includes careful palpationPalpation is an examination method in which the condition of body tissues is assessed by feeling them with the hands. It is used to identify swelling, pain, or other abnormalities. of the head and neck region to identify swelling as well as assessment of the regional lymph nodes. Modern imaging techniques play a central role in the diagnostic process. The ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. examination allows an initialInitial means beginning or at the start. In medicine, it can refer to the first symptoms of a disease or the first phase of a treatment process. assessment of the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. size, structure, and vascularization. Characteristic are hypoechoic, heterogeneousHeterogeneous describes a composition of different elements or components. In biology and medicine, it often refers to tissues, cells, or molecules that vary in structure, function, or both. massesIn pathology, the term "mass" is used to describe an abnormal lump or growth in the body. A mass can form in the skin or subcutaneous tissue, or even inside the body. The causes can be benign (not cancer) or malignant (cancer). with irregular margins and increased blood flow in Doppler mode.
Computed tomography (CT)Computed tomography (CT) is an imaging technique that uses X-rays and computer technology to create cross-sectional images of the body. It enables a detailed view of bones, organs, and other structures and is used for the diagnosis of injuries, diseases, and for planning medical interventions. and magnetic resonance imaging (MRI)Magnetic resonance imaging is an imaging technique that uses strong magnetic fields and radio waves to create detailed images of the inside of the body. It is used in veterinary medicine to diagnose diseases of the brain, spine, and other organs. provide more detailed information on local tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. extension and are particularly valuable for preoperative planning. MRI with contrast typically shows heterogeneousHeterogeneous describes a composition of different elements or components. In biology and medicine, it often refers to tissues, cells, or molecules that vary in structure, function, or both. signal intensity with contrast enhancement and allows precise delineation from surrounding structures. CT is particularly suitable for assessing bony infiltrationInfiltration refers to the penetration or accumulation of cells or fluids in a tissue or area that is normally free of them. This can occur as part of inflammatory reactions, Tumors, or other pathological processes. and for metastasisA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body. screening.
The definitive diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. is based on histopathologicalHistopathological refers to the microscopic examination of tissue samples for the diagnosis of diseases. This technique is used to identify the specific characteristics of diseases at the cellular level in dogs and cats. examination. A fine needle aspiration can provide initialInitial means beginning or at the start. In medicine, it can refer to the first symptoms of a disease or the first phase of a treatment process. cytological clues, but is often not sufficient for definitive diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients.. An incisional biopsyA biopsy is a medical procedure in which a small amount of tissue is removed from the body to be examined under a microscope for signs of disease. Biopsies can help diagnose cancer and other conditions. or complete excision with histopathologicalHistopathological refers to the microscopic examination of tissue samples for the diagnosis of diseases. This technique is used to identify the specific characteristics of diseases at the cellular level in dogs and cats. workup is the gold standard. Immunohistochemical studies with markers such as cytokeratin, vimentin, and Ki-67 can provide additional prognostic information.
For complete stagingStaging is the process of determining the extent of a disease's spread, especially in cancer. It helps classify the severity of the condition and plan an appropriate treatment strategy., chest X-rays in three planes or, ideally, a CT scan of the thorax to rule out pulmonaryPulmonary refers to the lungs or the respiratory system. Pulmonary diseases in dogs and cats include conditions such as Pneumonia, asthma, and pulmonary hypertension. metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body., as well as an ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. examination of the abdomenThe abdomen, also known as the abdominal cavity, is the part of the body located between the rib cage and the pelvis. It houses several important organs, including the stomach, liver, kidneys, intestines, and spleen., are indicated.
Therapy
- Surgical removal: For locally limited tumors, resection (sialoadenectomy) together with surrounding tissue is often the therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. of choice.
- Radiation therapyRadiation therapy is the use of radiation, most often to treat cancer. It can be used to kill cancer cells or slow their growth without significantly damaging surrounding healthy tissue.: Can be useful postoperatively (adjuvant), especially if it was not possible to cut into healthy tissue or the risk of recurrence is high.
- ChemotherapyChemotherapy refers to the treatment of diseases, especially cancer, with chemical substances or drugs. It aims to kill cancer cells or prevent their growth, but can also affect healthy cells.: depending on the degree of malignancyMalignancy refers to the aggressiveness of a tumor, that is, its ability to grow invasively and metastasize. Malignant tumors can be life-threatening in dogs and cats and require specific treatment. and stage (especially in case of metastasisA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body.). A fixed protocol does not exist; agents such as carboplatin or doxorubicin are often used.
- Targeted Therapies: Initial studies are investigating tyrosine kinase inhibitors or immune checkpoint inhibitors, analogous to human medicine.
The treatment of canineCanine refers to anything related to dogs. The term is used to describe characteristics, diseases, or specific aspects that specifically affect dogs. salivary gland adenocarcinoma requires a multimodal approach, with surgical intervention being the basis of therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions.:
Wide surgical resection (sialoadenectomy) with adequate safety margins is the therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. of choice for localized tumors. Due to the infiltrative growth pattern, an en-bloc resection with a 2–3 cm safety margin should be aimed for. For tumors of the Glandula mandibularis or sublingualis, a partial mandibulectomy may be necessary, while tumors of the Glandula parotis require a complex parotidectomy with preservation of the facial nerve. Simultaneous regional lymphadenectomy is recommended, even in clinically unremarkable lymph nodes, as microscopic metastases are common.
Adjuvant radiation therapyRadiation therapy is the use of radiation, most often to treat cancer. It can be used to kill cancer cells or slow their growth without significantly damaging surrounding healthy tissue. has established itself as a valuable addition to surgical treatment, especially in cases of incomplete resection or high-grade malignancyMalignancy refers to the aggressiveness of a tumor, that is, its ability to grow invasively and metastasize. Malignant tumors can be life-threatening in dogs and cats and require specific treatment.. Modern protocols include fractionated radiation with total doses of 48 to 54 Gy, distributed over several weeks. Intensity-modulated radiotherapy (IMRT) enables a more precise dose distribution with sparing of the surrounding normal tissue.
ChemotherapyChemotherapy refers to the treatment of diseases, especially cancer, with chemical substances or drugs. It aims to kill cancer cells or prevent their growth, but can also affect healthy cells. is primarily used for metastatic disease or as adjuvant therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. in cases of high risk of recurrence. Platinum compounds (carboplatin, cisplatin) and anthracyclines (doxorubicin) show moderate efficacy. Newer studies are investigating combination protocols and metronomic therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. approaches to improve tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. control.
Targeted therapies are becoming increasingly important. Tyrosine kinase inhibitors such as Toceranib have shown promising results in initialInitial means beginning or at the start. In medicine, it can refer to the first symptoms of a disease or the first phase of a treatment process. studies. Immunotherapeutic approaches, including checkpoint inhibitors, are in clinical evaluation and could expand the therapeutic spectrum in the future.
Prognosis and follow-up care
The prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. depends on the stage of the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. at the time of diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients., the possibility of complete surgical removal, and the presence of metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body.. Cases detected and treated early have a better prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop..
- TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. stage and resection margin: With complete removal and if there are no metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body., the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. is often more favorable than with far advanced, metastasized tumors.
- Metastatic behavior: Salivary gland adenocarcinomas can metastasize particularly to regional lymph nodes and the lungs.
- Long-term survival: Some dogs live tumor-free for several years after successful surgery. If complete resection is not possible or metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body. are already present, life expectancy is significantly reduced.
Aftercare
- Regular check-ups: clinical examinations at intervals of 3 to 6 months, imaging procedures (X-rayX-ray is an imaging technique that uses X-rays to create images of the inside of the body. It is often used to diagnose bone fractures, lung diseases, and other conditions./ultrasound) for early detection of recurrences or metastases.
- Wound and scar care: After an operation, pay attention to signs of infection.
- Management of accompanying symptoms: if necessary, pain management, monitoring of eating and drinking habits, and support for difficulty swallowing (dysphagiaDysphagia is the medical term for difficulty swallowing. In dogs and cats, dysphagia can be caused by diseases of the mouth, pharynx, or esophagus and impair the animal's ability to eat.).
Prevention
Salivary gland adenocarcinoma is rare but can be detected early if owners regularly palpate the head and neck area of their dog. Swelling in the jaw, throat, or neck area should be examined by a veterinarian promptly. Difficulty swallowing (dysphagiaDysphagia is the medical term for difficulty swallowing. In dogs and cats, dysphagia can be caused by diseases of the mouth, pharynx, or esophagus and impair the animal's ability to eat.), increased salivation, or weight loss can also be warning signs. Good dental hygiene and regular mouth checks contribute to mouth and salivary gland health. In breeds with increased tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. frequency, close preventive examinations are useful. Since the causes are largely unknown, the focus is on early detection and immediate clarification of conspicuous changes.
Outlook on current research
Research on canineCanine refers to anything related to dogs. The term is used to describe characteristics, diseases, or specific aspects that specifically affect dogs. salivary gland adenocarcinoma has made significant progress in recent years, opening up new diagnostic and therapeutic perspectives:
In the field of molecular diagnostics, next-generation sequencing technologies enable comprehensive genetic characterization of these tumors. Current studies are identifying specific mutationA mutation is a permanent change in the DNA sequence (genetic material) of an organism. In dogs and cats, mutations can lead to genetic diseases or desirable changes in certain traits. patterns and gene expression profiles that have both prognostic significance and could represent potential therapeutic targets. Liquid biopsy technology, which detects circulating tumor DNADNA (deoxyribonucleic acid) is the molecule that carries the genetic instructions for the development, function, and reproduction of all known living organisms and many viruses. It is located in the cells of an organism and contains the information for heredity. in the blood, is currently being evaluated for monitoring and early detection of recurrences.
Innovative imaging techniques such as PET-CT with tumor-specific tracers improve the precision of stagingStaging is the process of determining the extent of a disease's spread, especially in cancer. It helps classify the severity of the condition and plan an appropriate treatment strategy. and enable functional assessment of the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. tissue. These methods can optimize therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. planning and evaluate the response to treatment earlier.
In the therapeutic area, current research focuses on personalized treatment approaches. Preclinical studies are investigating the efficacy of EGFR inhibitors and MEK inhibitors in tumors with corresponding molecular alterations. Immuno-oncology is gaining increasing importance – checkpoint inhibitors such as anti-PD-1/PD-L1 antibodies are being evaluated in clinical trials and are showing promising initialInitial means beginning or at the start. In medicine, it can refer to the first symptoms of a disease or the first phase of a treatment process. results in various canineCanine refers to anything related to dogs. The term is used to describe characteristics, diseases, or specific aspects that specifically affect dogs. tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. diseases, including salivary gland adenocarcinomas.
Local therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. options are being expanded by technological innovations. Stereotactic radiation therapyRadiation therapy is the use of radiation, most often to treat cancer. It can be used to kill cancer cells or slow their growth without significantly damaging surrounding healthy tissue. enables a more precise application of higher radiation doses while sparing the surrounding tissue. Electrochemotherapy, which combines local electropermeabilization with systemic chemotherapyChemotherapy refers to the treatment of diseases, especially cancer, with chemical substances or drugs. It aims to kill cancer cells or prevent their growth, but can also affect healthy cells., is being evaluated for inoperable tumors.
Translational research approaches use the similarities between canineCanine refers to anything related to dogs. The term is used to describe characteristics, diseases, or specific aspects that specifically affect dogs. and human salivary gland tumors to gain new insights for both species. This comparative oncologyOncology is the branch of medicine that deals with the diagnosis, treatment, and research of cancer. In veterinary medicine, this includes the treatment of cancers in animals. could accelerate the development of new therapies and deepen the understanding of tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. biology.
Frequently asked questions (FAQs)
1. What is Salivary Gland Adenocarcinoma in Dogs?
Salivary gland adenocarcinoma is a malignant tumor that originates from the gland-forming cells of the salivary gland. According to Withrow & MacEwen’s Small Animal Clinical OncologyOncology is the branch of medicine that deals with the diagnosis, treatment, and research of cancer. In veterinary medicine, this includes the treatment of cancers in animals., these tumors are rare but can grow invasively and metastasize.
2. What Symptoms Indicate Salivary Gland Cancer?
Typical are palpable swelling in the neck or jaw area, difficulty swallowing (dysphagiaDysphagia is the medical term for difficulty swallowing. In dogs and cats, dysphagia can be caused by diseases of the mouth, pharynx, or esophagus and impair the animal's ability to eat.), increased drooling, and sometimes pain when eating. petsvetcheck.de points out that general symptoms such as weight loss, apathyApathy refers to a state of indifference and reduced interest or lack of emotional involvement in activities or events that would normally arouse interest., or bad breath can also occur.
3. How is the Diagnosis Made?
- Clinical examination: PalpationPalpation is an examination method in which the condition of body tissues is assessed by feeling them with the hands. It is used to identify swelling, pain, or other abnormalities., assessment of swelling.
- Imaging: UltrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow., X-rayX-ray is an imaging technique that uses X-rays to create images of the inside of the body. It is often used to diagnose bone fractures, lung diseases, and other conditions., CT/MRI for precise localization of the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. and exclusion of metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body..
- BiopsyA biopsy is a medical procedure in which a small amount of tissue is removed from the body to be examined under a microscope for signs of disease. Biopsies can help diagnose cancer and other conditions./fine needle aspiration: Histological or cytological confirmation.
The BSAVA Manual of Canine and FelineFeline refers to anything related to cats. The term is used to describe diseases, behaviors, or anatomical aspects that are specific to cats. OncologyOncology is the branch of medicine that deals with the diagnosis, treatment, and research of cancer. In veterinary medicine, this includes the treatment of cancers in animals. also recommends comprehensive tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. stagingStaging is the process of determining the extent of a disease's spread, especially in cancer. It helps classify the severity of the condition and plan an appropriate treatment strategy. for therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. planning.
4. Are there Risk Factors for Salivary Gland Adenocarcinoma?
Concrete risk factors have so far been little researched. Chronic inflammatory conditions of the salivary glands, genetic predispositionA predisposition is an innate inclination or susceptibility of an organism to certain diseases or conditions. In dogs and cats, there may be a genetic predisposition to certain conditions such as hip dysplasia or certain heart diseases., and possibly environmental influences could play a role. A clear connection with breed or gender has not yet been clearly proven.
5. What Treatment Options are Available?
- Surgery (sialoadenectomy): Most effective if the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. is detected in the early stages.
- Radiation therapyRadiation therapy is the use of radiation, most often to treat cancer. It can be used to kill cancer cells or slow their growth without significantly damaging surrounding healthy tissue.: for incomplete resection margins or extensive tumors.
- Chemotherapy: especially in case of metastasisA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body. or high risk of recurrence.
According to Slatter’s Textbook of Small Animal Surgery, the specific procedure depends on the location, size, and extent of the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions..
6. What is the Prognosis for Salivary Gland Cancer?
The prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. varies. If the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. is detected early and completely removed, some dogs can maintain a good quality of life for several years. However, with pronounced metastasisA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body. or inoperable tumors, life expectancy is significantly lower.
7. Can Salivary Gland Tumors Metastasize?
Yes, especially in lymph nodes of the neck region and in the lungs. Therefore, follow-up checks (e.g., X-rayX-ray is an imaging technique that uses X-rays to create images of the inside of the body. It is often used to diagnose bone fractures, lung diseases, and other conditions. of the thorax, ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow.) are essential to detect metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body. early.
8. How Can I Support My Dog after an Operation?
- Wound control: Pay attention to redness, swelling, or secretion.
- Rest: The dog needs rest, avoidance of stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being., and possibly soft food.
- Regular veterinary follow-up examinations: for monitoring the course and early detection of recurrences.
9. Are there Ways to Prevent Salivary Gland Cancer in Dogs?
Targeted preventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring. is difficult because clear causes are rarely defined. However, a healthy lifestyle with high-quality food, regular check-ups, and early intervention for swelling or inflammatory conditions can minimize the risk.
10. What is the Quality of Life for a Dog with a Salivary Gland Adenocarcinoma?
With early diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and successful therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions., dogs can often live a long time with a good quality of life. Close monitoring by the veterinarian and adapted care are essential, especially if adjuvant therapies are necessary.
When to visit the vet?
Non-urgent see a veterinarian within 2–3 days
If the condition worsens / symptoms persist, consult a veterinarian.