There is conflicting data regarding the role of PBAF complex mutations and response to immune checkpoint blockade (ICB) therapy in clear cell renal cell carcinoma (ccRCC) and other solid tumors. We assess the prevalence of PBAF complex mutations from two large cohorts including the pan-cancer TCGA project (n = 10,359) and the MSK-IMPACT pancancer immunotherapy cohort (n = 3700). Across both cohorts, PBAF complex mutations, predominantly PBRM1 mutations, are most common in ccRCC. In multivariate models of ccRCC patients treated with ICB (n = 189), loss-of-function (LOF) mutations in PBRM1 are not associated with overall survival (OS) (HR = 1.24, p = 0.47) or time to treatment failure (HR = 0.85, p = 0.44). In a series of 11 solid tumors (n = 2936), LOF mutations are not associated with improved OS in a stratified multivariate model (HR = 0.9, p = 0.7). In a current series of solid tumors treated with ICB, we are unable to demonstrate favorable response to ICB in patients with PBAF complex mutations.
Background: One of the main challenges in the management of renal cell carcinoma (RCC) is risk-stratifying patients who present with metastatic disease. Tumor size is an important predictor of survival in the localized setting; however, this feature has not been explored fully in patients presenting with M1 RCC.Objective: To assess the impact of tumor size on survival in patients with metastatic RCC who underwent cytoreductive nephrectomy (CN).Design, setting, and participants: We queried the Memorial Sloan Kettering (MSK) nephrectomy database for patients who presented with M1 disease and underwent CN between 1989 and 2016 (n = 304). Primary tumor size was obtained from pathology reports. Data from the International Metastatic Database Consortium (IMDC) were used for validation purposes (n = 778).Outcome measurements and statistical analysis: Overall survival (OS) estimates were computed using the Kaplan-Meier method. Cox regressions were used to test the association between tumor size and OS in univariate and multivariable analyses. Tumors ≤4 cm were compared with larger masses. Secondary analyses were performed to assess the robustness of these findings.
Results and limitations:Clear cell tumors ≤4 cm were significantly associated with improved OS in both the MSK (hazard ratio [HR]: 0.35, 0.17-0.72, p = 0.004) and IMDC (HR 0.54, 0.36-0.83, p = 0.004) cohorts. The association was observed even after adjusting for known prognostic factors (HR 0.40, 0.14-1.14, p = 0.09 and HR: 0.54, 0.33-0.90, p = 0.02 in the MSK and IMDC cohorts, respectively). Limitations of this study include the absence of patients who were considered poor surgical candidates as well as potential selection bias.
Conclusions:The primary tumor size ≤4 cm was independently associated with improved OS in patients with metastatic clear cell RCC who underwent CN. Additionally, the association between primary size and survival was found to be nonlinear. These findings suggest that there is a group of small metastatic RCCs that can convey a better overall prognosis. The potential role of primary tumor size when risk stratifying patients with M1 RCC should be explored further to determine its utility during clinical decision making.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.