Correlation between familial cancer history and epidermal growth factor receptor mutations in Taiwanese never smokers with non-small cell lung cancer: a case-control study.

BACKGROUND

Lung cancer is a leading cause of cancer deaths in the world. Cigarette smoking remains a prominent risk factor, but lung cancer incidence has been increasing in never smokers. Genetic abnormalities including epidermal growth factor receptor (EGFR) mutations predominate in never smoking lung cancer patients. Furthermore, familial aggregations of patients with these mutations reflect heritable susceptibility to lung cancer. The correlation between familial cancer history and EGFR mutations in never smokers with lung cancer requires investigation.

METHODS

This was a retrospective case-control study that evaluated the prevalence of EGFR mutations in lung cancer patients with familial cancer history. Never smokers with lung cancer treated at a hospital in Taiwan between April 2012 and May 2014 were evaluated. Inclusion criteria were never smokers with non-small cell lung cancer (NSCLC). Exclusion criteria involved patients without records of familial cancer history or tumor genotype.

RESULTS

This study included 246 never smokers with lung cancer. The study population mainly involved never smoking women with a mean age of 60 years, and the predominant tumor histology was adenocarcinoma. Lung cancer patients with familial cancer history had an increased prevalence of EGFR mutations compared to patients without family history [odds ratio (OR): 5.9; 95% confidence interval (CI): 3.3-10.6; P<0.001]. Specifically, 57 out of 85 cancer patients (67%) with familial cancer history had these mutations, while 41 out of 161 patients (25%) without family history harbored mutations. Subgroup analysis also revealed that patients with familial lung cancer history had stronger association with EGFR mutations (OR: 7.5; 95% CI: 3.4-16.3; P<0.001) compared to patients with family history of non-pulmonary cancers (OR: 5.0; 95% CI: 2.5-10.0; P<0.001).

CONCLUSIONS

The study demonstrated an increased prevalence of EGFR mutations in Taiwanese never smoking lung cancer patients with familial cancer history. Moreover, a sizable proportion of never smoking cancer patients harbored these mutations. These observations have implications for the treatment of lung cancer in never smokers.