Abstract
The prognostic features of T1N0M0 renal cell carcinoma (RCC) in Asian patients have not been well explored in large sample studies. In this study, we retrospectively analyzed the records of 713 patients undergoing nephrectomy for T1N0M0 RCC between 1991 and 2009 in three Asian hospitals. Univariate and multivariate analysis were performed to identify the independent predictive factors for T1N0M0 RCC prognosis among a series of clinicopathological parameters, including age, gender, tumor size, Fuhrman grade, and histological classification. Our results showed that 388 of 713 patients had tumors 4.0 cm or smaller (stage T1a) and 325 of 713 patients had tumors 4.0-7.0 cm in size (stage T1b). Five-year cancer-specific survival (CSS) and recurrence-free survival (RFS) rates for this group of patients were 96.0% and 93.5%, respectively. The patients with T1b RCC had a significantly lower 5-year CSS and RFS rates than did those with T1a RCC (CSS, 93.1% vs. 98.6%, P = 0.026; RFS, 90.0% vs. 96.5%, P < 0.001). Patients with low grade (grades I-II) tumors had a higher 5-year CSS (97.8% vs. 91.2%, P = 0.001) and RFS (95.5% vs. 85.5%, P < 0.001) rate than did those with high grade (grades I-II) tumors. More interestingly, when stratifying patients to T1a and T1b groups, the role of grade in distinguishing prognosis could be only observed in patients with T1b disease. Cox regression showed tumor size and Fuhrman grade were significant in predicting CSS and RFS. Our study suggests that the prognosis of patients with T1N0M0 RCC is excellent, and these results are comparable to previously reported studies in Western patients. Furthermore, our data indicates that patients with T1b disease and high Fuhrman grade have high risk of tumor recurrence and death, thus requiring more frequent follow-up.