Natural history and clinical outcome of sporadic renal cortical tumors diagnosed in the young adult.

OBJECTIVES: To determine the natural history of patients younger than 40 years (young patient [YP] group) who are diagnosed with a sporadic renal cortical tumor (RCT) and to compare the natural history of these patients with the more typical older patient (OP) with RCT.

METHODS: We reviewed our database and identified 34 patients (younger than 40 years old, median age 35) who underwent surgery for a sporadic RCT. The YP group outcomes were compared with 100 patients between 41 and 85 years (median 65). We fit a Cox proportional hazards model to examine the relationship between age at presentation and recurrence risk.

RESULTS: The median tumor size in the YP group was 3.8 cm (range 0.6 to 19) and in the OP group was 5.0 cm (range 0.9 to 22; P = 0.225). Tumors were discovered incidentally in 51% and 56% of the YP and OP groups, respectively (P = 0.65). The frequency of partial nephrectomy did not differ between the two groups (35% YP and 30% OP, P = 0.55). The frequency of malignant histologic subtypes did not differ between the groups (P = 0.439). In the YP group, only larger tumor size (hazard ratio 1.23, 95% confidence interval 1.02 to 1.50, P = 0.034) was associated with a statistically significant increased risk of recurrence. Those in the YP group were not more or less likely to develop recurrence than those in the OP group (hazard ratio 0.79, 95% confidence interval 0.22 to 2.85, P = 0.72). The 5-year disease-free survival rate was 73% and 80% in the YP and OP groups, respectively (P = 0.23). The 5-year disease-specific survival rate was 85% and 84% in the YP and OP groups, respectively (P = 0.88).

CONCLUSIONS: The findings of our study indicate that the natural history of RCTs is similar in both younger and older patients. Young patients were neither more nor less likely to develop recurrence compared with their older counterparts.