Presentation Authors: Hiroshi Fukushima*, Kazutaka Saito, Yosuke Yasuda, Kenji Tanabe, Masahiro Toide, Shohei Fukuda, Minato Yokoyama, Junichiro Ishioka, Yoh Matsuoka, Tokyo, Japan, Dattatraya Patil, Atlanta, GA, Brittney Cotta, Sunil Patel, San Diego, CA, Viraj Master, Atlanta, GA, Ithaar Derweesh, San Diego, CA, Yasuhisa Fujii, Tokyo, Japan
Introduction: There is no consensus regarding sex differences of prognosis in clear cell renal cell carcinoma (CCRCC) patients. Recently, several basic studies reported that androgen receptor signaling can promote the progression of CCRCC, suggesting that males may have worse prognosis compared with females. The prognostic role of sex and its underlying genetic and hormonal backgrounds can be different depending on baseline characteristics of patients. Here, we investigated the effect of sex on prognosis of non-metastatic CCRCC patients undergoing curative surgery using the inverse probability of treatment weighting (IPTW) approach.
Methods: This study included 2055 cT1-4N0M0 CCRCC patients undergoing partial or radical nephrectomy at three institutions (Tokyo Medical and Dental University, Japan; Emory University, GA; University of California San Diego, CA) from 1993 to 2018. The variables analyzed were age, sex, race, surgery type, pT stage and Fuhrman&[prime]s grade. We used IPTW analysis to adjust for baseline characteristics between females and males (age, race, surgery type and pT stage). Recurrence was defined as the development of local recurrence and/or metastatic disease. The association of sex with recurrence-free survival (RFS) was evaluated using the Cox proportional hazards models.
Results: During the median follow-up of 30 months, 162 (8%) patients recurred (5-yr RFS rate, 88%). Male sex (n=1,343, 65%) was significantly associated with higher Fuhrman&[prime]s grade (p=0.008). Males had significantly worse RFS than did females (5-yr RFS rate, 86% vs 92%, p=0.002, Fig). On multivariate analysis, male sex was an independent predictor for RFS (HR 1.72, p=0.004) along with higher pT stage (HR 2.98, p < 0.001) and higher Fuhrman&[prime]s grade (HR 3.27, p < 0.001). In subgroup analyses by race, males tended to have worse RFS compared with females in all races including Caucasians, African-Americans and Asians.
Conclusions: Male sex was significantly associated with worse prognosis of non-metastatic clear cell renal cell carcinoma patients undergoing curative surgery.