Previous reports have shown higher survival rates in women than in men with non-small cell lung cancer (NSCLC), and oestrogen receptors are expressed on human NSCLC cells. 14 676 women from the US 1992–1997 Surveillance, Epidemiology, and End Results database with primary NSCLC were categorised as premenopausal (age 31–50 years, n = 2230) or postmenopausal (51–70 years, n = 12 446), the average age of menopause being taken as 51 years. Young (n = 3022) and older men (n = 19 819) were grouped according to the same age ranges.

Worse clinical stage and histology was more common in premenopausal women than in postmenopausal women, and curative surgery was attempted less frequently (31% v 33%, p = 0.03). Lung cancer related deaths were higher in postmenopausal women than in premenopausal women when adjusted for stage, histology, size, grade, and extent of surgery (hazard ratio (HR) 1.14, 95% CI 1.03 to 1.27). Significant covariate adjustment revealed similar lung cancer related deaths in young men and women, but more deaths in older men than in premenopausal women (HR 1.26, 95% CI 1.15 to 1.40). Younger men presented with a more advanced clinical stage than older men, and both male groups had worse presentation and lower crude survival than their female counterparts.

The authors hypothesise that premenopausal NSCLC may be initiated by higher oestrogen concentrations, but any oestrogen exposure in life may confer a protective effect which determines the outcome of the neoplastic process. Age is an important potential confounder in this study. Although survival was higher in women than in men of both age groups, the comparison of the two older age groups was based on crude and not adjusted data. The absence of information about hormone replacement therapy or oral contraceptives is an important omission. Nevertheless, with many of the benefits previously attributed to oestrogen now being called into question, this study should prompt a further more detailed analysis of the effects of oestrogen with respect to lung cancer.