BACKGROUND: The purpose of this study was to identify predictive factors for late recurrence in Korean patients with stage T1 clear cell renal cell carcinoma (RCC) more than 5 years after treatment with radical nephrectomy (RN) or partial nephrectomy (PN). PATIENTS AND METHODS: Between 1999 and 2011, 3567 patients with RCC underwent RN or PN at 5 institutions in Korea. Of these, 423 patients with pathologically confirmed stage T1 clear cell RCC remained free of disease for at least 5 years. To determine the pathologic and clinical factors that influenced late recurrence, univariate and multivariate analyses using the Cox proportional hazards model were performed. Recurrence-free survival curves were estimated by using the Kaplan-Meier method. RESULTS: During a median follow-up period of 83.9 months (range 60.0-156.4 months), late recurrence was observed in 14 of the 423 (3.3%) patients. Univariate and multivariate analyses revealed that symptoms at diagnosis and pathologic T stage were independent predictive factors for late recurrence. Patients with symptoms at diagnosis or stage T1b disease had a significantly shorter time to late recurrence than did those who were asymptomatic or had stage T1a disease (log-rank test P = .027 and P = .034, respectively). CONCLUSIONS: Late recurrence in stage T1 clear cell RCC is a relatively rare event. Predictive factors for late recurrence were identified in the present study. Careful long-term follow-up is necessary, especially in patients who have symptoms at diagnosis or stage T1b tumors, even if they have been free of disease for more than 5 years.
BACKGROUND: The purpose of this study was to identify predictive factors for late recurrence in Korean patients with stage T1 clear cell renal cell carcinoma (RCC) more than 5 years after treatment with radical nephrectomy (RN) or partial nephrectomy (PN). PATIENTS AND METHODS: Between 1999 and 2011, 3567 patients with RCC underwent RN or PN at 5 institutions in Korea. Of these, 423 patients with pathologically confirmed stage T1 clear cell RCC remained free of disease for at least 5 years. To determine the pathologic and clinical factors that influenced late recurrence, univariate and multivariate analyses using the Cox proportional hazards model were performed. Recurrence-free survival curves were estimated by using the Kaplan-Meier method. RESULTS: During a median follow-up period of 83.9 months (range 60.0-156.4 months), late recurrence was observed in 14 of the 423 (3.3%) patients. Univariate and multivariate analyses revealed that symptoms at diagnosis and pathologic T stage were independent predictive factors for late recurrence. Patients with symptoms at diagnosis or stage T1b disease had a significantly shorter time to late recurrence than did those who were asymptomatic or had stage T1a disease (log-rank test P = .027 and P = .034, respectively). CONCLUSIONS: Late recurrence in stage T1 clear cell RCC is a relatively rare event. Predictive factors for late recurrence were identified in the present study. Careful long-term follow-up is necessary, especially in patients who have symptoms at diagnosis or stage T1b tumors, even if they have been free of disease for more than 5 years.