Significant association between EGFR-mutated lung adenocarcinoma and past illness from gastric cancer or uterine myoma: its implication in carcinogenesis.

The present study investigated the potential difference between EGFR-mutated lung adenocarcinoma (ADC) and KRAS-mutated ADC in relation to past illness and family history. Among the 153 tumors examined, 33 (21.6%) were EGFR-mutated, and 22 (14.4%) were KRAS-mutated. The EGFR-mutated cases showed a significantly higher prevalence of past illness involving the gastric cancer in males (EGFR 3/8 (37.5%), KRAS 0/13 (0.0%), no mutation (NONE) 1/57 (1.8%); Fisher's exact test, P=0.0064) or uterine myoma in females (EGFR 8/25 (32.0%), KRAS 0/9 (0.0%), NONE 3/41 (7.3%); Fisher's exact test, P=0.0139). No association between the mutations and family history was found. The EGFR-mutated ADC is therefore likely to develop through a distinct carcinogenetic pathway from the others, but genetic backgrounds seemed unlikely to be determinant predisposing to the EGFR-mutated ADC.