Dochters van vrouwen die tijdens de zwangerschap rookten hebben in latere jaren minder last van borstkanker.
Dit is het verrassende resultaat van een vervolgonderzoek op de oude DES-gegevens dat werd uitgevoerd door onderzoekers van het Tufts-New England Medical Center in Boston.
The reason for the finding may be connected to estrogen, which is linked to breast cancer risk.
“Clinical studies show that maternal cigarette smoking reduces pregnancy estrogen levels,” Strohsnitter, of Tufts-New England Medical Center, Boston, and colleagues write in the medical journal Epidemiology. “Women prenatally exposed to maternal cigarette smoke may, therefore, have a lower breast cancer risk.”
The team’s report is based on an analysis of data from the National Cooperative DES Adenosis project, a follow-up study that examined the health outcomes in women exposed in the womb to diethylstilbestrol (DES), a drug later found to have harmful effects.
The study participant’s mothers gave information about their smoking habits during pregnancy. The investigators then compared the rates of breast cancer among some 4000 women who were or were not exposed to maternal cigarette smoke before they were born.
After adjustment for other risk factors, women exposed in the womb to cigarette smoke had approximately half the breast cancer rate as those not exposed.