Epidemiological Trend of Esophageal Cancer at a Tertiary Cancer Center in Mumbai, India, Over the Past 15 Years.

BACKGROUND: In developed countries, there has been a definite change in the histopathological spectrum of esophageal cancer towards adenocarcinoma. There are limited data from India regarding the histopathological profile of patients with esophageal cancer. MATERIALS AND METHODS: We retrospectively evaluated patients with histologically proven esophageal cancer who were registered at the Tata Memorial Hospital (Mumbai, India) between 2003 and 2018. The primary aim of the study was to analyze the time-trend of the histological pattern of esophageal cancer. Our secondary objectives included evaluating whether there was any correlation between the histology of the esophageal cancer and the age, sex, socioeconomic status (the paying ability of the patient, which was reflected in the treatment category of the patient, i.e., private [full payment], general [subsidized payment], or no charge), comorbidities, and a history of substance abuse. RESULTS: Among 7874 patients with esophageal cancer, 5092 (64.7%) were men, with a male-to-female ratio of 1.8:1. The median age was 57 years (IQR, 50-65). Of the 4912 patients in whom a history of tobacco or alcohol use had been elicited, 1360 (27.7%) had no history of substance abuse. A majority of the tumors (2942, 37.4%) originated in the middle-third of the esophagus. Squamous cell carcinoma was the predominant histological type, noted in 6413 (81.4%) patients and remained the most common histologic type consistently through the study with no evidence of a time-trend in the histological pattern. On the multivariate analysis, female sex and a history of substance abuse were associated with higher odds of squamous cell carcinoma, while the presence of comorbidities and lower esophageal/gastroesophageal junction primaries were associated with higher odds of adenocarcinoma. CONCLUSIONS: There is no evidence of an epidemiological shift in the histopathologic spectrum of esophageal cancer in India over the last two decades. Four out of five Indian patients with esophageal cancer have squamous cell histology, with the commonest site of origin being the middle third. This is important to recognize, given the varying molecular spectrum and efficacy of therapeutic modalities based on histopathology.

Clinical Utility of Liquid Biopsy (Cell-free DNA) Based EGFR Mutation Detection Post treatment Initiation as a Disease Monitoring Tool in Patients With Advanced EGFR-mutant NSCLC.

INTRODUCTION: Plasma cfDNA-based mutation analysis has shown disease-monitoring potential in various cancers. We assessed the potential of cfDNA-based EGFR mutation testing as a monitoring tool in patients with NSCLC. PATIENTS AND METHODS: Patients with NSCLC harboring EGFR mutations receiving first-line treatment as per institutional protocol were enrolled. EGFR mutation status was determined using plasma samples at baseline and post treatment initiation. Patients in whom EGFR mutation was detected or persisted after treatment initiation were considered circulating tumor DNA (ctDNA)-positive. Progression-free survival (PFS) and overall survival (OS) for ctDNA-positive and negative patients post treatment initiation were the primary endpoints; concordance for baseline EGFR status between tissue and plasma and proportion of patients who were ctDNA-positive post treatment initiation were the secondary endpoints. RESULTS: We enrolled 158 patients; 76 received gefitinib, and 82 received gefitinib plus chemotherapy. Median follow-up duration was 42 months. About 25% of patients were ctDNA-positive post treatment initiation. Median PFS for ctDNA-negative patients post treatment initiation was 14 (95% confidence interval [CI], 12.0-17.0) months, while that for ctDNA-positive patients was 8 (95% CI, 6.0-10.0) months. Median OS for ctDNA-negative patients post treatment initiation was 27 (95% CI, 24.0-32.0) months, while that for ctDNA-positive patients was 15 (95% CI, 11.0-19.0) months. Concordance at baseline between tissue and plasma samples was 75.4%. CONCLUSION: Plasma-based EGFR mutation detection post treatment initiation can be used as a predictive marker for outcome in patients with EGFR-mutant NSCLC receiving first-line treatment.