WHEP Scholar Ashni Nadgauda
Drexel University College of Medicine, Class of 2021

Lung cancer is the second most common cancer after breast cancer in women, after prostate cancer in men, and is the leading cause of cancer-related deaths worldwide. The proportion of lung cancer cases in women attributed to smoking is half that of those in men. Approximately 20% of women with lung cancer have never smoked, versus only 2-6% in men. In Asian populations, the rate of lung cancer in women who have never smoked is estimated at 60%-80%, in contrast to 10%-15% in men that have never smoked.

Estrogen receptors (ER-alpha and ER-beta) and aromatase have been detected on lung cancer cells. Studies looking at the relationship between hormone replacement therapy (HRT) and lung cancer have yielded mixed results; some studies show that HRT is associated with decreased incidence of lung cancer and others show an association with increased incidence.

Mutations in the estrogen growth factor receptor (EGFR) gene are among the most common genetic alterations found in non-small cell lung cancer (NSCLC), occurring in 34% of all lung adenocarcinomas. They are found in a higher proportion of lung cancer patients who do not smoke, especially Asian females. Research has shown that strong expression of ER-beta is associated with a favorable prognosis after treatment with EGFR-tyrosine kinase inhibitor (TKI) treatment.

My research sought to determine if, in patients affected with EGFR mutated non-small cell lung cancer, there is a gender difference in recurrence and, in female patients, if estrogen levels are linked to recurrence and outcome to TKI treatment. Univariate analyses of estrogen and recurrence were performed. Local recurrence and T790M mutation were seen to be significant in relation to a positive estrogen status. Estrogen status was not seen to be significant in relation to recurrence.