Assessment of time from cytoreductive nephrectomy (CN) to initiation of targeted therapy (TT) in patients with metastatic renal cell carcinoma (mRCC).

Abstract

540 Background: For patients (pts) with de novo mRCC, the initiation of TT typically occurs at a window of 4-6 weeks following CN. Although this practice is thought to mitigate impaired wound healing, bleeding and other complications (cx) in the perioperative period potentially related to antiangiogenic TT, there is limited data to support this practice. Methods: An institutional database including over 670 pts with RCC was interrogated. Pts with de novo mRCC who had received CN and subsequent TT were identified. When available, demographic data, Charlson comorbidity index (CCI), body mass-index (BMI) and surgical data (estimated blood loss [EBL], intraoperative cx, etc.) were recorded. ICD-9 codes recorded up to 90 days following CN were evaluated; newly applied diagnoses with possible relationship to surgery were considered to be potential postoperative cx. For continuous variables, the Spearman correlation test was used to determine associations with time to TT. For categorical variables, Kaplan-Meier analyses were conducted to determine if time to TT varied across subgroups. Results: Of 270 pts with mRCC, 79 pts received cytoreductive nephrectomy. Of these, 36 pts received TT as an initial treatment strategy (others received IL-2, IFN or chemotherapy), and 30 pts had a documented date of TT initiation. Two pts were removed given receipt of preoperative TT, resulting in a total of 28 pts in the current analysis. Median time to TT was 46 days (range, 28-93). Median overall survival for the overall cohort was 17.2 months. No association was found between age, BMI, CCI, number of sites of metastasis and time to TT. Time to TT did not vary by race (Caucasian v other) or class of TT (VEGF-directed therapy v mTOR inhibitor). Furthermore, EBL and the frequency of intraoperative cx did not vary by time to TT. The most frequently encountered postoperative cx included pleural effusion, pain, fatigue and nausea. Conclusions: With the caveat of our small sample size, the lack of an association between operative cx and time to TT suggests that an abbreviated timeframe between CN and TT may be entertained. These findings warrant exploration in larger series and/or prospective validation.