Oncology Resident University of Pennsylvania Philadelphia, Pennsylvania, United States
Abstract:
Background: Tumor-infiltrating lymphocytes (TILs) have been associated with prognosis in both human and canine malignancies. The number of intratumoral cytotoxic T-lymphocytes (CTLs) have been positively associated with survival in human renal cell carcinoma (RCC) whereas the number of intratumoral T-regulatory (Treg) cells have been negatively associated with RCC survival.
Hypothesis/
Objectives: To evaluate the association of TIL density with survival times in canine RCC (CRCC). A secondary aim was to evaluate associations of clinicopathologic and histologic variables with CRCC survival times.
Animals: Fifteen dogs diagnosed with CRCC between 2008 and 2021.
Methods: Cases of CRCC were identified retrospectively and hematoxylin and eosin sections were reviewed to evaluate histologic prognostic variables (mitotic index, Fuhrman nuclear grade, vascular invasion, local invasion, histopathological subtype, sarcomatoid change). TIL density was quantified using immunohistochemistry (CD3, FoxP3, granzyme-B) and subsequent manual or automatic cell counting via ImageScope software. Kaplan-Meier curves were created to estimate progression free survival (PFS) and overall survival (OS). Potential prognostic subsets were compared using the log rank test.
Results: Median PFS and OS were 524 and 739 days, respectively. No significant association between CD3, FoxP3, or granzyme-B positive TIL density with survival was identified. No histologic variable assessed was associated with patient outcome. Elevated GGT prior to nephrectomy was negatively associated with PFS on single variable analysis.
Conclusions and clinical importance: TIL density was not associated with prognosis in CRCC. Elevated GGT prior to nephrectomy was identified as a potential negative prognostic indicator.
