Adenocarcinoma of the vagina: association of maternal stilbestrol therapy with tumour appearance in young women
Eight young women in Boston developed a vaginal cancer almost never seen at their age; seven of their mothers had taken the synthetic oestrogen diethylstilbestrol in pregnancy. It was the first proof that a drug given to a mother could cause cancer in her child decades later.
Overview
Case-control study of eight women aged 15 to 22 with clear cell adenocarcinoma of the vagina diagnosed in Boston between 1966 and 1969, each matched to four controls born in the same hospital within days.
Seven of the eight mothers had taken diethylstilbestrol (DES) during the first trimester, against none of the 32 control mothers. The finding led to the withdrawal of DES in pregnancy and to the recognition of transplacental carcinogenesis.
- Maternal DES exposure in the first trimester in 7 of 8 cases versus 0 of 32 matched controls.
Clear cell adenocarcinoma of the vagina is the archetype of a cancer caused by exposure before birth; DES-exposed daughters still need lifelong gynaecological surveillance, and the paper is the reason drugs in pregnancy are now scrutinised for effects on the child.
- Eight cases; the association was confirmed by registries over the following decades.
- Most vaginal adenocarcinomas today arise without DES exposure.