Female Gender Predicts Favorable Prognosis in Patients With Non-metastatic Clear Cell Renal Cell Carcinoma Undergoing Curative Surgery: Results From the International Marker Consortium for Renal Cancer (INMARC).

ABSTRACT

BACKGROUND: There is no clear consensus regarding gender differences in the prognosis of patients with clear-cell renal cell carcinoma (ccRCC). In the present study, we investigated the prognostic value of gender in patients with non-metastatic ccRCC undergoing curative surgery using the inverse probability of treatment weighting (IPTW) method to balance the difference in baseline factors between females and males. PATIENTS AND METHODS: We retrospectively reviewed the International Marker Consortium for Renal Cancer (INMARC) dataset and included 2055 patients with cT1-4N0M0 ccRCC who underwent partial or radical nephrectomy. The IPTW method was used to adjust for baseline characteristics between females and males (age, race, surgery type, and pT stage), and the association of gender with recurrence-free survival (RFS) was evaluated. RESULTS: During the follow-up (median, 30 months), 162 (8%) patients had disease recurrence (5-year RFS rate, 88%). Female gender (n = 712; 35%) was significantly associated with a lower Fuhrman grade (unweighted, P = .022; IPTW-weighted, P < .001). Females had significantly better RFS compared with males (unweighted, 5-year RFS rate, 92% vs. 87%; P = .005; IPTW-weighted, 5-year RFS rate, 92% vs. 86%; P = .002). IPTW-weighted multivariate analysis showed that female gender was an independent predictor for better RFS (hazard ratio, 0.59; P = .005) along with lower pT stage and lower Fuhrman grade. The prognostic significance of female gender was also observed in the unweighted multivariate analysis. CONCLUSION: Female gender was significantly associated with a lower Fuhrman grade and better prognosis for patients with non-metastatic ccRCC undergoing curative surgery.