Renal cell carcinoma in young adults: incidence, disease outcome and review of the literature.

OBJECTIVE: To study the incidence, clinical presentation and pathological prognostic factors affecting disease outcome of RCC in young adults less than 40 years old.
METHODS: The charts o medical records of 400 patients treated surgically for RCC between January 1984 and December 1999 were reviewed. 29 (7.25%) patients were under 40. We used ANOVA regression and Chisquare (Fisher exact test) to assess the prognostic value of the quantitative and qualitative variables, respectively. Estimation of the survival distributions were calculated according to Kaplan-Meier method and compared with Log rank test. Multivariate analysis of the entire population utilizing Cox models was performed.
RESULTS: The most common histological cell type was clear cell carcinoma, found in 20 (69%) patients. At a median follow-up of 80 months, 20 (69%) patients were disease free and 9 (31%) died of the disease. Incidental discovery (p = 0.05), tumor stage (p = 0.043), grade (p = 0.011), lymphatic invasion (p < 0.0001) metastasis (p = 0.003), adrenal invasion (p = 0.024), and renal vein invasion (p < 0.0001) were associated with prognosis (Kaplan-Meier). When comparing patients less than 40 years vs. older than 40 years, we found significant differences in histology type (clear cell carcinoma 69% vs. 91%; p = 0.0001), and tumor stage at presentation (pT2 = 34.5% vs. 17.3%; p = 0.04) (pT3 = 20.7% vs. 42%; p = 0.03). Disease free survival was not significantly different between the two groups (69% vs. 65.7%; Log rank test p = 0.4).
CONCLUSION: Although rare, RCC in young adults seems to follow a course similar to the disease seen in older patients. Among the prognostic factors studied incidental discovery, pathological stage of the tumor and grade, were associated with survival. Stage at presentation was different between the two populations however survival was not affected by age.