Andy H. Abbo, DVM, MS, DACVIM (Oncology), Veterinary Cancer Specialists of New England
YOU HAVE ASKED...
What do I need to know about primary lung cancer and digital metastasis in cats?
THE EXPERT SAYS...
Primary Lung Tumors & Metastasis
Primary lung cancer in domestic cats is rare, with <1% of all cancers diagnosed in cats1; however, metastatic cancer of the lungs is more common.2 No incidence data have been reported.
Reported primary lung tumors (Figures 1 and 2) include squamous cell carcinoma and sarcoma, but adenocarcinomas are reportedly the most common histopathologic diagnosis. Adenocarcinomas are subcharacterized by location (ie, bronchial, bronchioloalveolar, alveolar) and grade. Carcinomas are graded on histopathology as differentiated or undifferentiated, with the grade directly correlating with metastatic incidence.
Although most primary carcinomas are localized and solitary at diagnosis, the literature suggests that >50% of undifferentiated carcinomas and 90% of squamous cell carcinomas metastasize,1,3 with one study reporting ≈75% of feline lung tumors as metastatic. Metastasis to the lungs, skin, CNS, and digits may occur transpleurally, hematogenously, or via lymphatics or airways.