Impact of smoking status on clinical outcomes in patients with metastatic renal cell carcinoma treated with first-line immune checkpoint inhibitor-based regimens

BACKGROUND: Current tobacco smoking is independently associated with decreased overall survival (OS) among patients with metastatic renal cell carcinoma (mRCC) treated with targeted monotherapy (VEGF-TKI). Herein, we assess the influence of smoking status on the outcomes of patients with mRCC treated with the current first-line standard of care of immune checkpoint inhibitor (ICI)-based regimens. MATERIALS AND METHODS: Real-world data from the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) were collected retrospectively. Patients with mRCC who received either dual ICI therapy or ICI with VEGF-TKI in the first-line setting were included and were categorized as current, former, or nonsmokers. The primary outcomes were OS, time to treatment failure (TTF), and objective response rate (ORR). OS and TTF were compared between groups using the log-rank test and multivariable Cox regression models. ORR was assessed between the 3 groups using a multivariable logistic regression model. RESULTS: A total of 989 eligible patients were included in the analysis, with 438 (44.3%) nonsmokers, 415 (42%) former, and 136 (13.7%) current smokers. Former smokers were older and included more males, while other baseline characteristics were comparable between groups. Median follow-up for OS was 21.2 months. In the univariate analysis, a significant difference between groups was observed for OS (P = .027) but not for TTF (P = .9), with current smokers having the worse 2-year OS rate (62.8% vs 70.8% and 73.1% in never and former smokers, respectively). After adjusting for potential confounders, no significant differences in OS or TTF were observed among the 3 groups. However, former smokers demonstrated a higher ORR compared to never smokers (OR 1.45, P = .02). CONCLUSION: Smoking status does not appear to independently influence the clinical outcomes to first-line ICI-based regimens in patients with mRCC. Nonetheless, patient counseling on tobacco cessation remains a crucial aspect of managing patients with mRCC, as it significantly reduces all-cause mortality.