A clinico-epidemiological, pathological, and molecular study of lung cancer in Northwestern India

Lung cancer is the most common malignant disease and is the topmost cause of cancer deaths in the world across all age groups and in both sexes. It is the most common cause of cancer deaths in developed countries and is also rising at an alarming rate in the developing countries.

The present study was undertaken to explore the clinicopathological and molecular profile of bronchogenic carcinoma in northwestern population of India.

A total of 136 consecutive patients with histologically proven bronchogenic carcinoma, registered between May 2014 and April 2016 at a tertiary care hospital in New Delhi, India, were analyzed.

Out of a total of 136 diagnosed cases, 6% were in the third to fourth decade of life, 49% in the fifth to sixth decade, and 45% in the seventh decade and above. Seventy-one percent of patients were male. Smoking was the major risk factor in 65.40% of patients. About 33% of female patients were smokers with a significant overlap in the use of smoking objects. Twenty-one percent of patients had been initially empirically treated with antitubercular therapy. Most common symptoms at presentation were cough, dyspnea, weight loss, and chest pain. Pleural effusion, paraneoplastic phenomenon, clubbing, peripheral lymphadenopathy, and Pancoast syndrome were the major signs at presentation. Twenty-one percent of nonsmokers and 40% of smoker patients presented with ECOG Performance Status 3 or 4. Ninety-three percent of patients presented in stage III or IV. Metastases to skeleton, brain, liver, pleura, adrenals, lung, and distant lymph nodes were present in 30.8%, 16.9%, 15.4%, 15.4%, 14.7%, 13.2%, and 11.8%, respectively. Fiberoptic bronchoscopy was found to be the most efficient diagnostic procedure as compared to transthoracic and thoracoscopic methods. Histologically, squamous cell carcinoma, adenocarcinoma, and small cell carcinoma and its variants were seen in 35.30%, 44.9%, and 15.40% cases, respectively. Nearly 4.4% of patients were diagnosed as poorly differentiated carcinoma. Driver mutations (epidermal growth factor receptor or anaplastic lymphoma kinase) were detected in 48% (25 of 52 tested) of adenocarcinomas and 55.55% (5 of 9 tested) of young, nonsmoker, female squamous cell carcinoma patients.

This study highlights that the adenocarcinoma incidence is surpassing squamous cell carcinoma in Indian lung cancer patients also, as observed in Western population. Mean age at diagnosis is about one decade earlier than in the Western population. Driver mutations are more common in India than in the West as also reported in other Asian studies.