Predictors of Cytoreductive Nephrectomy for Metastatic Kidney Cancer in SEER and Metropolitan Detroit Databases.

Patients without cytoreductive nephrectomy (CN) are inadequately represented in metastatic renal cell carcinoma (RCC) clinical trials. The characteristics that impact the decision of CN were explored in the SEER database. Data on primary, regional, or distant (metastatic) stage kidney cancer over the period 2000-2013 were extracted from the National Cancer Institute Surveillance, Epidemiology, and End Results Program (SEER-18) database. A sub-analysis of Metropolitan Detroit cases, to evaluate the influence of comorbidities, was conducted. Logistic regression was used to calculate the odds ratios, and Cox model was used to calculate hazard ratios; 37% of 21,052 metastatic RCC cases had CN performed. CN demonstrated significant survival advantage (HR = 0.31, 95% confidence interval [CI]: 0.30-0.33). Comorbidity data were available on 76% of distant RCC cases from the Detroit SEER database. Neither hypertension, diabetes mellitus nor the number of comorbidities (0, 1 or 2) had a statistically significant impact on the likelihood of CN. Majority of patients (63%) with distant-stage RCC do not undergo CN and have a median overall survival (OS) of 3 months as compared to a median OS of 18 months for patients who have undergone CN. Patient demographics and tumor characteristics make a significant impact on the incidence of CN. The impact of comorbidities (number and type) was modest and not statistically significant. The optimal management of patients with synchronous primary and metastatic RCC needs to be prospectively evaluated in the setting of contemporary systemic therapy.