Morphologic and Molecular Analysis of 39 Spontaneous Feline Pulmonary Carcinomas

Abstract

The present study was performed to determine the morphologic change and selected molecular features of spontaneous lung tumors in cats examined at the North Carolina State University Veterinary Teaching Hospital. Thirty-nine primary lung carcinomas represented 0.69% of all feline cases admitted to the hospital. Most lung tumors were observed in aged cats (P < .0001), and no sex predilection was found (P < .4241). Persian cats with pulmonary carcinoma were overrepresented in the data set, at least 4 times more frequently than other breeds. The histologic tumor types included adenocarcinoma (64.1%), bronchioloalveolar carcinoma (20.5%), and adenosquamous carcinoma (15.4%). Metastasis was observed in about 80% of 39 cases, with decreasing order of intrapulmonary metastasis, intrathoracic carcinomatosis, regional lymph nodes, and distant organs, including digits. The size of the largest tumor mass was significantly associated with metastatic potential (P < .001). Based on immunohistochemistry, more than 80% (20 of 24) of feline lung tumors were positively labeled with either surfactant protein A or thyroid transcription factor 1. Epidermal growth factor receptor mutant and p53 proteins were detected in approximately 20% (5 of 24) and 25% (6 of 24) of the feline lung tumor cases, respectively. Limited sequencing analysis of K-ras and p53 genes in 3 selected normal and neoplastic lung tissues did not reveal any alteration. Results indicate that primary lung carcinomas are rare but aggressive tumors in cats, thereby warranting further studies on molecular carcinogenesis.

Pulmonary Carcinoma Metastasis in a Feline Digit

“…The lung-digit syndrome is more common in elderly cats, with a mean age of 10 to 14 years [1]. No breed or gender predisposition has been reported in felines, with the possible exception of Persian cats [5]. The present report, which describes the case of a 16-year-old Himalayan cat (a cross between the Persian and Siamese breeds), agrees with most studies suggesting that older cats are more often affected.…”

Immunohistochemistry characterization of a bronchioloalveolar carcinoma mixed subtype in cat

“…In cats, the incidence of lung carcinoma has increased in the last years (2,5,14). This finding may be explained by longer lifespans and an increase in the number of animal necropsies being performed and reported (2,14). This population is composed by older domestic cats, short hair, and with a mean age of 12 years.…”

“…TTF-1 has been described as a highly specific marker in lung adenocarcinomas in human and dog (7,11). D'Costa et al, (2) showed a labeling specificity of 66.7% in feline lung tumors and it was the highest percentage when compared with other antibodies Surfactant A (SP-A) (50%), Epidermal growth factor receptor (EGFR) (20.8%) and p53 (25%), suggesting the importance of these protein as marker to support the diagnosis of pulmonary tumors in the cat. In this case, histochemical (PAS) and immunohistochemistry (CK7, CK20 and TTF-1) staining were useful for the diagnostic of pulmonary tumor and as well as their classification.…”

“…In contrast, is an infrequent found in domestic animals (2,11). Spontaneous lung tumors are more frequently in dogs, cats and sheep (6,8).…”

“…According to these studies, the main tumors types observed in dogs and cats are acinar adenocarcinoma, bronchioloalveolar carcinoma, adenosquamous and squamous cell tumors (3,8,9,14). In the cat, the predominant pattern is adenocarcinoma, with less frequent adenosquamous or squamous and bronchioloalveolar subtypes (2,4,5,14).…”