Pregnancy drug popular from 1950s-70s blamed for breast cancer in "DES daughters"

Drug giant Eli Lilly this week settled a lawsuit brought by four sisters with breast cancer who believe their disease was caused by a pregnancy drug their mother took during pregnancy in the 1950s. The settlement could lead to more such claims being won by other women with breast cancer whose moms took Diethylstilbestrol, also known as DES, a synthetic estrogen widely prescribed until 1971. The drug was also widely administered to US dairy and beef cattle, via their feed.

Above, an ad placed by a DES drug maker in major medical journal in 1957, urging obstetricians to prescribe it to all pregnant women. At the time, the drug was not yet patented. The small print reads:

Recommended for routine prophylaxis in ALL pregnancies... 96 per cent live delivery with desPLEX in one series of 1200 patients - bigger and stronger babies, too. No gastric or other side effects with desPLEX - in either high or low dosage.
DES Action Info, a nonprofit that connects people exposed to DES, says:
It is now known that DES exposure is related to health problems in the sons and daughters of the women who took it, and in the women themselves.

The National Cancer Institute has an explainer on DES, including its effects on sons and daughters of women who took it. A CDC page on DES is here. DES Action has a well-documented timeline of the drug's history here.

The issue doesn't just affect women: Male children and grandchildren of DES users also face elevated risks of certain kinds of cancers, according to these sources.

There's a good LA Times piece on the DES settlement here. And CBS News ran a report earlier this week, before the settlement was reached in this most high-profile and precedent-setting "DES Daughters" case.

(Images courtesty DES Action)