A prospective study of lung cancer found no strong links between lung cancer risk and a range of reproductive history variables.
The Women’s Health Initiative Observational Study and Clinical Trials enrolled a geographically and ethnically diverse cohort of 161,808 postmenopausal women age 50-79 years between 1993 and 1998 at 40 centers across the United States. Reproductive history, oral contraceptive use, and hormone therapy replacement was evaluated in the 160,855 women eligible to be included in the analysis. Incident lung cancer was observed in 2,467 and the median follow-up was 14 years.
The results published in the Journal of Thoracic Oncology, the official journal of the International Association for the Study of Lung Cancer, show that women with previous use of estrogen plus progestin (< 5 years) were at a slightly reduced risk for lung cancer. Increasing age at menopause trended towards reduced risk whereas increasing number of children trended towards increased risk. Those who were age 20-29 at the birth of their first child had reduced risk of non-small cell lung cancer (NSCLC), but not all lung cancer. Risk estimates for hormone therapy usage and previous surgery to remove both ovaries varied with tobacco exposure history.