Prognostic significance of high nuclear grade in patients with pathologic T1a renal cell carcinoma

A reliable prognostic indicator in patients with pathologic T1a renal cell carcinoma has not yet been fully elucidated. The aim of this study was to investigate the prognosis of pathologic T1a renal cell carcinoma cases with a special focus on pathological factors.

The study population consisted of 338 patients diagnosed with solitary renal cell carcinoma at our hospital between 1996 and 2009. The relationship between disease progression and clinicopathologic features was analyzed retrospectively to determine if it affected recurrence and distant metastasis.

The Fuhrman nuclear grade distribution between the tumors was 1, 2, 3 and 4 in 68 (20.1%), 242 (71.6%), 21 (6.2%) and 7 cases (2.1%), respectively. A total of 11 subjects were identified as having recurrent tumors (3.3%), 9 of whom had metastatic lesions. Multivariate analysis showed that the appearance of tumor Grade 3 and 4 (hazard ratio: 13.0, 95% confidence interval: 3.90-43.0, P < 0.001) was an independent risk factor for tumor recurrence, while no significant correlation was found between tumor recurrence and age, gender, tumor side, tumor size, surgical methods, histology, microvascular invasion or surgical margin status. The 5-year recurrence-free survival rate was 67.8% in patients with a high nuclear grade tumor, and 96.8% in their counterparts.

High nuclear grade is possibly one of the most important prognostic factors for predicting tumor recurrence and metastasis after surgery in pathologic T1a renal cell carcinoma. Thus, careful follow-up may be required in patients with pathologic T1a renal cell carcinoma of a high nuclear grade.