Impact of comorbidity on survival in cancer patients receiving immune checkpoint inhibitors.

Purpose: Immunotherapy efficacy in elderly patients with comorbidities and poor performance status is not well understood. More knowledge on this topic is needed to identify subgroups that will benefit from immunotherapy. We aimed to evaluate the effect of comorbidity burden in patients receiving immunotherapy.

Methods/patients: Patients older than 18 years of age and diagnosed with various malignancies, followed up in our tertiary cancer center were screened. Patients treated with immunotherapy were included in this study. We used to Charlson Comorbidity Index (CCI) to evaluate patients' comorbidity burden. The primary outcome was overall survival (OS). Hazard ratio (HR) with confidence interval (CI) was evaluated in multivariable analysis.

Results: A total number of 197 patients were included. The median age was 62 years. Patients were grouped based on CCI scores: CCI-low (≤ 8) and CCI-high (> 8). One-hundred and seven patients (54.9%) had metastatic disease at the time of diagnosis. Most frequently used immunotherapy agent was nivolumab (n = 124, 62.9%), followed by pembrolizumab (n = 36, 18.3%). The median OS was shorter in the CCI-high group than in the CCI-low group (10.6 vs. 21.2 months, p = 0.002) In multivariable analysis, treatment with anti-CTLA4 (HR: 1.85, 95% CI 1.07-3.20, p = 0.028), ECOG performance status (2-4 vs. 0-1) (HR: 2.17; 95% CI 1.25-3.75; p = 0.005), and higher CCI scores (CCI-high vs. CCI-low) (HR: 1.97; 95% CI 1.3-3.0; p = 0.001) were independently associated with worse OS.

Conclusions: Comorbidity burden and performance status independently predict survival outcomes in immunotherapy-treated cancer patients. Comprehensive comorbidity assessment is essential for optimizing treatment and improving patient outcomes.