What types of cancer are commonly found in domestic cats?

Common Cancer Types in Domestic Cats

Lymphoma is the most common cancer in domestic cats, followed by mammary tumors, squamous cell carcinomas, soft tissue sarcomas, and mast cell tumors. 1, 2, 3

Primary Cancer Types by Frequency

Lymphoma (Most Common)

• Lymphoma represents the most frequently diagnosed neoplasm of the hematopoietic system in cats, with cats having the highest incidence of lymphoma among all species. 2, 3
• The incidence of feline lymphoma has actually increased over time despite decreased FeLV infection rates, rising from 1982 to 2003 at major veterinary teaching hospitals. 3
• Intestinal lymphoma has become the predominant form in the post-FeLV era, accounting for much of the increased incidence, while FeLV-associated types (mediastinal and multicentric) have decreased. 3
• Renal lymphoma occurs in approximately 3.6% of all feline lymphoma cases, with both isolated renal involvement and multicentric disease patterns. 4
• Mediastinal lymphomas show high incidence in young Siamese or Oriental breed cats. 3
• Lymphoma can occur at virtually any anatomic site, in cats of any age, and in both FeLV-infected and uninfected animals. 2

Mammary Tumors

• Mammary tumors rank as one of the most common malignancies in domestic cats, second only to lymphoma in overall frequency. 1
• These tumors are included among the major cancer types requiring genetic investigation in feline oncology research. 1

Squamous Cell Carcinomas

• Squamous cell carcinomas represent a significant proportion of feline cancers, particularly affecting cutaneous and oral sites. 1
• This cancer type is recognized as one of the common malignancies warranting dedicated genetic and molecular studies in cats. 1

Soft Tissue Tumors

• Soft tissue sarcomas constitute an important category of feline neoplasia, including injection-site sarcomas and other mesenchymal tumors. 1
• These tumors are among the common cancer types identified in comprehensive feline oncology databases. 1

Mast Cell Tumors

• Mast cell tumors occur with sufficient frequency in cats to be classified among the common feline malignancies. 1
• Both cutaneous and visceral forms are recognized in feline patients. 1

Less Common but Clinically Significant Cancers

Hemangiosarcomas

• Hemangiosarcomas represent a less frequent but important vascular malignancy in cats. 1

Pulmonary Carcinomas

• Primary lung carcinomas occur in cats, though less commonly than in dogs. 1

Pancreatic Carcinomas

• Pancreatic tumors are rare in cats but are recognized as part of the feline cancer spectrum. 1

Osteosarcomas

• Bone tumors including osteosarcomas occur in cats, though with lower frequency compared to canine patients. 1

Important Clinical Considerations

Age and Presentation Patterns

• Cancer is a significant cause of morbidity and mortality in domestic cats, with apparent incidence increasing as cats live longer and receive more veterinary care. 5
• Tumors are often relatively advanced at presentation in cats, making early management challenging. 5
• Neoplasia should be included in the differential diagnosis for virtually any clinical problem in any body system in cats. 2

Diagnostic Approach

• Limited robust evidence exists for most feline tumors compared to canine or human cancers, making clinical decision-making more challenging. 5
• Cytogenetics, gene-specific mutation analysis, methylation studies, and next-generation sequencing are increasingly being applied to understand feline cancer genetics. 1

Common Pitfall

• Do not assume all masses in cats are benign or that cancer only occurs in older cats—lymphoma can affect cats of any age, and many tumor types present across the age spectrum. 2, 3