Oncology deals with prevention, diagnosis, and treatment of cancer. Clinical oncology consists of three primary disciplines: medical oncology (the treatment of cancer with medicine including chemotherapy), surgical oncology (the surgical aspects of cancer including biopsy, staging and surgical resection of tumors), radiation oncology (the treatment of cancer with therapeutic radiation).
Each oncology case is medically unique, hence the approach must also be patient-specific consisting of the following components:
- Staging (determining the extent of local disease and pre of regional or distant metastasis)
- Therapeutic intervention (based on tumor type, histologic grade, and stage)
- Provisions for patient and personnel safety in handling chemotherapy agents
- Referral to an oncology speciality practice like MaxVets when appropriate
- A strong emphasis on client support.
Because cancer is often a disease of older pets, which is the time of life when the pet-owner relationship is usually the strongest, a satisfying outcome for all parties involved is highly dependent on good communication between the entire healthcare team and the client, particularly when death or euthanasia of the patient is being considered.
- Cancer is one of the leading causes of death in companion animals such as dogs and cats.
- It is particularly common in animals that live 10 years or longer but can occur at any age.
- Skin tumors are one of the most frequently diagnosed type of tumor in pets (may be due to constant exposure of animal skin to the sun and the external environment and because they are easily observed from the outside). Dogs are 35 times more likely to suffer from skin cancers than humans.
At MaxVets, mast cell tumors, lymphomas, adenocarcinoma and osteosarcomas are the most commonly encountered.
Once the possibility of a neoplastic process (both malignant or benign growths) is suspected, determination of the tumor type serves as the basis for all subsequent steps in patient management.
- No confirmed diagnosis can be made be palpation alone.
- A biopsy is the basic tool that allows removal and examination of cells from the body to determine the presence, cause, or extent of a disease process.
- Samples for analysis are obtained by fine-needle sampling (for cytological examination) which can be performed safely for the majority of external tumors without anesthesia or sedation. Sometimes surgical excision biopsies are advised for diagnosis and staging, which requires complete general anesthesia.
- Pet owners should be prepared for repeated imaging and staging before the decision for final treatment options is made.
- Anal sac carcinoma: It occurs in the anal sac and is locally aggressive, hence, excision is difficult. It progresses slowly and is difficult to observe by symptoms alone unless renal function is compromised.
- Lymphoma: It is multicentric (node, liver, and spleen) and occurs in bone, CNS (Central Nervous System), mucocutaneous tissue and skin. It is, thus, hard to treat.
- Mammary gland cancer: It occurs in one or more mammary glands and is most common type of cancer in females. Early spaying is advisable to prevent these tumors.
- Mast cell tumor: It occurs in skin and subcutaneous tissue and is locally invasive.
- Oral malignant melanoma: It occurs in the oral cavity and is more metastatic in lymph nodes than lungs.
- Osteosarcoma: It is a rare type of skeletal metastases observed in bones (proximal humerus, distal radius, distal femur, proximal and distal tibia).
- Soft tissue sarcoma: These are mesenchymal tumors occurring in skin and subcutaneous tissues. It is locally invasive.
- Splenic hemangiosarcoma: It is a highly metastatic splenic masses which cannot be definitively distinguished from HSA (Hemangiosarcoma) prior to treatment.
- Lymphoma: Commonly occurs in thymus, GI tract, liver, spleen, kidney and rarely mucocutaneous tissue. It is considered a systemic disease.
- Mammary gland cancer: It occurs in mammary glands and is highly metastatic and locally aggressive.
- Squamous cell carcinoma: It may be oral or cutaneous. It is extremely locally aggressive in case of oral and progresses slowly in case of cutaneous.
Soft tissue sarcomas: Occurring in cutaneous and subcutaneous tissue, it is extremely locally aggressive.