The post-operative pathological prognostic parameters of clear cell renal cell carcinoma in pT1a cases

There has been a recent increase in the number of small clear cell renal cell carcinoma (ccRCC) cases, particularly in pT1a cases. The prognostic parameters for small ccRCC, however, are not well described. Herein, we assess the pathological parameters of pT1a patients. Various clinicopathological parameters were analyzed in 293 patients with pT1a ccRCC without pre-operative metastasis to predict the disease-free survival rate (DFS) and the cancer-specific survival rate (CSS). Clinicopathological parameters included age, tumor location, Fuhrman grade, lymph-vascular invasion (LVI), tumor necrosis, and growth pattern (expansive or infiltrative). In the univariate analysis, Fuhrman grade (grade 1 + 2 vs. 3 + 4), LVI, growth pattern, and tumor necrosis were parameters associated with a worse prognosis (P < 0.0001) in both the DFS and CSS. In the multivariate analysis, Fuhrman grade (P = 0.0048), growth pattern (P = 0.0275), and tumor necrosis (P = 0.0188) were statistically significant in the DFS. Fuhrman grade (P = 0.0189) and growth pattern (P = 0.0016) were also statistically significant in the CSS. Fuhrman grade, tumor necrosis, and growth pattern were independent prognostic parameters in pT1a ccRCC. Growth pattern, a previously unrecognized parameter for prognosis, can be considered a new prognostic parameter in ccRCC.