Renal cell carcinoma: Analysis of postoperative recurrence patterns

PURPOSE: To retrospectively analyze the recurrence patterns of renal cell carcinoma (RCC) and the factors affecting tumor recurrence. MATERIALS AND METHODS: The institutional review board approved this study; patient informed consent was not required There were 162 men (mean age 54 years +/- 13 [standard deviation]) and 32 women (mean age, 56 years +/- 11) who had undergone complete surgical resection of RCC. Mean follow-up period was 45 months (range, 7-92 months). In consensus, two radiologists determined the presence or absence of tumor recurrence and recorded the time and sites of tumor recurrence. The relationships between tumor recurrence and tumor factors, including greatest diameter (greater than or equal to5 cm or <5 cm), T stage, N stage, stage group, histologic subtype, and nuclear grade, were evaluated by using Kaplan-Meier statistics. RESULTS: Tumor recurred in 41 (21%) patients. The mean time of tumor recurrence was 17 months (range, 3-50 months). Tumor recurred within 2 years after surgery in 34 (83%) patients. Tumor recurrence sites included lung (n = 29), bone (n = 13), the nephrectomy site (n = 7), brain (n = 6), liver (n = 5), mediastinal lymph nodes (n = 5), the contralateral kidney (n = 4), and the neck muscles (n = 2). The recurrence rate was greater for tumors 5 cm or larger than for those smaller than 5 cm, greater for T3a or T3b tumors than for T1 tumors, greater for stage III tumors than for stage I tumors, and greater for tumors with a nuclear grade of 3 or 4 than for those with a nuclear grade of I or 2 (P < .05 for all). CONCLUSION: RCC usually recurs within 2 years after surgery, with the lung being the most vulnerable site; greatest tumor diameter, T stage, stage group, and nuclear grade are important factors for recurrence. (C) RSNA, 2004.