Prognostic Features of Anti-Cancer Drugs Response in Resected/Unresected Primary Non-Small Cell Lung Cancer: A Retrospective Cohort Study

Abstract Aim: Low chemotherapy response is a major risk factor for early mortality in cancer patients; it is one of the biggest challenges in cancer treatment. Main aim of this study is to identify chemotherapy non-responder, prognostic significance of pre-chemotherapy baseline variables in survival, distinguish most effective anti-cancer drug classes and formulation. Methods: In this multi-center retrospective cohort (n=2459) patients deceased with NSCLC and received anti-cancer drugs were included for analyses. To identify chemotherapy non-responder, patient population was divided into three sub-groups based on chemotherapy prescription frequency [1-15] as group-A, [16-30] as group-B, and [[&ge;]31] as group-C. Multivariate analysis was performed to identify risk of 1-year mortality in these groups. To prognose chemotherapy response in resected and unresected NSCLC patients, 0-7 days pre-chemotherapy white blood cell (WBC) count total five-ranges were compared as per overall survival in abnormal Vs normal WBC counts. Results: Post-stratification in group-A there were (n=1289) patients, in group-B (n=648) patients, and in group-C (n=522) patients. In group-A (n=301) patients 23% were found to have no new metastasis post-diagnosis significantly less p-value (0.004) compared to Group-B (n=125) 19.3%, and group-C (n=110) 19.2% patients p-value (0.008). Metastasis during chemotherapy was found significantly less in 20% patients of group-A, compared to (33%) in group-B, and (43%) in group-C p-value (<0.001). Post-chemotherapy initiation OS in group-A patients were significantly less 9 months (95% CI 9.3 - 9.6) compared to group-B 19 months (95% CI 17.7 - 20.2) and group-C 36.6 months (95% CI 34.6 - 38.5) patients p-value (<0.0001). Despite of low new metastasis and post chemo metastasis, group-A patients survived significantly less based on these outcomes group-A patients were considered as chemotherapy non-responder. Males and NSCLC stage III/IV patients were at higher risk; clinical benefits are corelated to surgery and radiotherapy for chemotherapy non-responder. Leukocytosis in both resected/unresected NSCLC group-A (13%) patients were found to be bad prognostic factor of survival in unresected group-B (5%) patients. Oral formulation of receptor tyrosine kinase inhibitors (RTKI) was effective in non-responders. Conclusion: Stratification of patient population based on chemotherapy prescriptions could be a useful method to find chemotherapy response in retrospective analysis. Patients with pre-chemotherapy leukocytosis should be closely monitored prior to selection of chemotherapy dose and formulation.