Role of mitochondrial DNA 4977-bp deletions in esophageal cancer susceptibility and prognosis in a northern Indian population

The mitochondrial DNA 4977-bp deletion (▵mtDNA4977) has been explored in various cancers, but its predictive or prognostic role in esophageal cancer is poorly understood. The objective of the present study was to investigate a possible role of ▵mtDNA4977 in susceptibility and prognosis of esophageal cancer in a northern Indian population. The study was performed in 39 histopathologically confirmed cases with esophageal cancer. Tumor, normal tissues, and intravenous blood samples were taken for detection of ▵mtDNA4977 through a duplex polymerase chain reaction technique. ▵mtDNA4977 was detected in two tumors and one adjacent normal tissue sample, but in none of the blood samples. All three patients with ▵mtDNA4977 were male, with squamous cell carcinoma in the middle third of the esophagus. Survival analysis suggested a role of ▵mtDNA4977 in prognosis of esophageal cancer patients. Despite the low frequency of ▵mtDNA4977 in esophageal cancer patients of northern India, this feature may have a role in esophageal cancer progression and prediction of survival outcome.