Lung Cancer in Non-Smokers: Clinicopathological and Survival Differences from Smokers

Abstract

BackgroundLung cancer in non-smokers is a clinically distinct entity based on unique epidemiology, clinicopathology, genetics, treatment response, and outcome. Data from Indian centres are scarce. The objective of this study was to compare the frequency, clinical characteristics, driver mutations, and survival of non-smoking and smoking lung cancer patients treated at a tertiary cancer centre in North India. MethodologyTwo years of data on 724 consecutive lung cancer patients were assessed. Clinical, demographics, smoking history, and EGFR and ALK mutation test results were collected. Descriptive and inferential statistics were applied. Survival analysis was performed using the Kaplan-Meier method. ResultsNon-smokers comprised 40.9% of the study sample. Non-smokers were more likely than smokers to experience disease onset at a younger age (P = 0.004) and metastasis (P < 0.001). The tumor histology showed significant differences (P < 0.001), with non-smokers more likely to be diagnosed with adenocarcinoma (77.4%), while squamous and small cell histologies were commonly found among smokers (37.6% and 13.8%, respectively). The EGFR mutation and ALK rearrangement rates in the cohort were 23.3% and 10.1%, respectively, and were more frequent in non-smoking patients. Overall, 10-year survival was 7%, with a significantly better survival rate of non-smokers than smokers (median survival time of 15.13 vs 10.17 months; P = 0.012). ConclusionsAbout four out of 10 patients diagnosed with lung cancer at our centre were non-smokers. They were more often young, diagnosed at an advanced stage, with predominantly adenocarcinoma histology, and had a threefold higher frequency of EGFR mutations than smokers. In our cohort, non-smokers appear to be a targetable group with better survival than smokers.

Programmed Death Ligand -1 and Gene Mutation Characterization of Lung Malignancies in Patients at a Rural Hospital in Central India

“…We detected PD-L1 expression and EGFR mutation status in lung malignancies in a rural hospital in Central India. We found EGFR mutation in 8% In our study, > 80% of the patients were male (male:female ratio 4.1:1) with an age range of 36-80 years (mean age 63 years) as also observed in most of the studies from India (Vasudevan et al,2022;Nath et al, 2022). Although tobacco smoking (50% current smokers) is considered as a major risk factor for lung malignancies, the prevalence (10-30%) of lung malignancies are now increasing among non-smokers as well (Ou, 2013) which could be because of exposure to environmental carcinogens as dust, insecticides, indoor smoke or cooking smoke from Chullas in Indian settings (Vasudevan et al, 2022).…”

“…We found EGFR mutation in 8% In our study, > 80% of the patients were male (male:female ratio 4.1:1) with an age range of 36-80 years (mean age 63 years) as also observed in most of the studies from India (Vasudevan et al,2022;Nath et al, 2022). Although tobacco smoking (50% current smokers) is considered as a major risk factor for lung malignancies, the prevalence (10-30%) of lung malignancies are now increasing among non-smokers as well (Ou, 2013) which could be because of exposure to environmental carcinogens as dust, insecticides, indoor smoke or cooking smoke from Chullas in Indian settings (Vasudevan et al, 2022). Cough (80%) is reported as the most common symptom but other systemic symptoms as fever (22.9%) and weight loss (17.2%) of unknown cause should also be methodically investigated to rule out any pulmonary malignancies (Malik et al, 2013).…”

“…Studies have describes the clinico-pathology characteristics of lung malignancies from various parts of India (Vasudevan et al,2022;Nath et al, 2022;Bhopal et al, 2019;Shanmugapriya Shankar et al, 2014;Malik, 2013), but limited data is available on the clinical, pathology features and the types of mutation in lung malignancies from Central India.…”