Repurposing calcium channel blockers: may be sensible combination with erlotinib for non-small cell lung cancer.

Erlotinib is a tyrosine kinase inhibitor that inhibits epidermal growth factor receptor. It is being used for metastatic non-small cell lung cancer patients (NSCLC). Repurposing noncancer drugs for cancer treatment is a current issue and it has many advantages. We planned to reveal the effects of noncancer drugs [calcium channel blockers (CCBs) and others] on erlotinib. We scanned the files of NSCLC patients retrospectively who were applied to Karadeniz Technical University between January 2013 and April 2019 and used erlotinib. There were 63 patients, 9 of them were taking CCB simultaneously for arterial hypertension. We analyzed some parameters of these patients and their effects on overall survival (OS) and progression-free survival (PFS). A χ2 or Fisher's exact test, Kaplan-Meier and Cox regressions were used in the statistical analysis. 12-month OS rates of CCB user and nonuser were 78.3 and 39.7%, respectively, [odds ratio (OR),0.14; 95% confidence interval (CI), 0.27-0.75; P = 0.023]. 24-month PFS rates of CCB user and nonuser were 44.4 and 8.3%, respectively (OR,0.11; 95% CI, 0.02-0.60; P = 0.016). There was 12-month OS and 24-month PFS advantage with simultaneously taking CCBs and erlotinib, they have an additive effect for NSCLC. This study will be inspiring future prospective studies.