Prognostic Factors Affecting the Overall Survival and Disease-Free Survival in Carcinoma Lung Patients Treated with Sequential Chemoradiation and Concurrent Chemoradiation: A Retrospective Study

Introduction: Lung cancer is the most commonly occurring cancer worldwide accounting for 12.4% of total new cases and also the leading cause of cancer deaths (18.7%). In India, Lung cancer accounts for 5.8% of new cases and 8.2% of cancer deaths. Chemotherapy and Radiation therapy plays a major role in treatment especially in inoperable cases. In this study we evaluated the factors which could affect the Overall Survival (OS) and Disease -Free Survival (DFS) in patients with Lung carcinoma treated by Sequential Chemoradiation (CTRT) and Concurrent CTRT. Materials and Method: A retrospective review was carried out on 38 patients with Lung carcinoma who were treated with either Concurrent or Sequential CTRT at our institute. Various factors like age, gender, habits, disease laterality, histology, group stage, treatment received and radiation dose were evaluated. Results were analysed using IBM SPSS Statistics version 25 and Kaplan-Meier curves. Results: Median age of patients was 65 years. The majority were men (89.4 %) and smokers (57.8%). Adenocarcinoma (63.2%) was the most common histological type followed by Squamous cell (18.4%) and Small cell carcinoma (18.4%). Majority were left-sided tumors (52.6%). Most common stage was IIIA (44.7%) followed by IIIB (39.5%). Most of the patients were treated with Sequential CTRT (78.9%) and the rest with Concurrent CTRT (21.1%). The mean radiation dose used was 61.82Gy (Range: 45Gy-66Gy). The 2-year OS and DFS in all patients was 21% and 18.4% respectively and the 5-year OS and DFS was 13.1% and 10.5% respectively. OS and DFS was better in patients diagnosed at young age (36-45 years), females, non-smokers, Adenocarcinoma histology, left-sidedtumors, stage IIIA and treated with Sequential CTRT but was not statistically significant except for Stage IIIA (p=0.007) and left-sidedtumors (p=0.029) which had significantly better OS and DFS respectively. Conclusion: Young age, females, non-smokers, left-sided tumors, Adenocarcinoma histology are favorable prognostic factors for OS and DFS in Lung cancer patients. Left-sided tumors also had a better statistically significant DFS.