Population-based Study Evaluating The Prognosis Of Nephron-Sparing Surgery And Radical Nephrectomy In Surgical Treatment Of T1b,T2 Renal Cell Carcinoma

Objective:To analysis the prognosis of partial nephrectomy(PN)and radical nephrectomy(RN)in T1b-T2N0M0 renal cell carcinoma(RCC)based on population data.Methods:Patients treated with PN or RN for T1b-T2N0M0 RCC between 2004 and 2015 were identified from the Surveillance,Epidemiology,and End Results(SEER)database.Patients were classified by the surgery of PN and RN and 1:1 propensity matched with the method of “nearest” based on the likelihood of receiving PN.Overall survival(OS),RCC cause mortality and 30-and 90-day mortality were the main endpoint for comparison.Kaplan-Meier method to describe OS and the log-rank test for the differences.Multivariable Cox proportional hazards regressions and Fine and Gray competing risk proportional hazards regressions were used to predict all-cause mortality and RCC-cause mortality.R was used for data analysis.Results:19439 T1b-T2N0M0 RCC patients were identified,including 3,621 PN and 15818 RN.The median follow-up was 4.08 years.All patients with PN were better matched in the RNgroup.Although PN has been increasing year by year,in the population of T1b RCC,percent of PN increased from 9.9% in 2004 to 34.2% in 2015 meanwhile in the population of T2 RCC,percent of PN increased from 3.5% in 2004 to 10.1% in 2015,RN remains the main surgical procedure for patients with T1b-T2N0M0 RCC with 72.8% in 2015.After 1:1propensity-score matched,in the population of T1b,PN was associated with better OS(p =0.0015),however,in the population of T2 RCC,there existed no significant difference between PN and RN on OS(p = 0.27).In addition,in the population of T1b RCC,the cumulative incidence for RCC cause mortality and non-RCC cause mortality in the arm of PN was lower than RN arm(p<0.001).In the population of T2,the cumulative incidence for RCC-cause mortality in the arm of PN was lower than RN(p = 0.008),but it showed no significant difference(p = 0.751)for non-RCC cause mortality.When adjust for other risk predictor such as age,tumor nuclear grade,histological type of RCC and tumor size et al,we observed PN had a better prognostication in the population of T1b(HR = 0.815 [95%CI:0.692-0.959],p = 0.014),but In the population of T2(HR = 0.859 [95%CI:0.565-1.306],p= 0.480).There existed no significant difference for 30-,and 90-days mortality between the surgery PN and RN in two populations of T1b and T2.Conclusion:PN for T1b RCC compared with RN was associated with a significantly better OS but not the population of T2 RCC.There are some limitations in this study and requires further validation.