Sex-specific incidence of EGFR mutation and its association with age and obesity in lung adenocarcinomas: a retrospective analysis.

PURPOSE: Age and obesity are well-known risk factors for various cancers, but the potential roles of age and obesity in lung cancer, especially in those with activating EGFR mutations, have not been thoroughly evaluated. The aim of this retrospective study is to evaluate the associations between the sex-specific incidence of EGFR mutations and age and obesity.

METHODS: We conducted a retrospective study based on the data from 1378 lung adenocarcinoma cases. The degree of obesity was categorized by body mass index (BMI). The associations between EGFR mutational status and clinical factors, including stage, smoking history, age group (≤45 years, 46-55, 56-65 and >65), and BMI group (<18.5 kg/m(2), 18.5-22.9, 23.0-24.9 and ≥25.0) were analyzed using logistic regression models for each sex.

RESULTS: In men, the incidence of EGFR mutation was inversely associated with age (adjusted odds ratio [OR] for age group = 0.76, p-trend = 0.003) and positively associated with obesity (adjusted OR for BMI group = 1.23, p-trend = 0.04). In contrast, in women, the incidence of EGFR mutation was positively associated with age (adjusted OR for age group = 1.19, p-trend = 0.02). However, the incidence of EGFR mutation was not statistically associated with obesity (adjusted OR for BMI group = 1.03, p-trend = 0.76).

CONCLUSIONS: Our data suggests that age and obesity may contribute to the sex-specific incidence of EGFR mutation in lung adenocarcinoma in different manners.