Depot-
medroxyprogesterone acetate (
DMPA) has been used world-wide since 1964 as a
contraceptive in spite of the fact that it was only in 1992 licensed for
contraceptive use in the USA due to concern about a possible
breast cancer risk. Two recent studies have considered
DMPA use and risk of
breast cancer and these and earlier studies are reviewed here. Overall, the results are reassuring but there is some evidence that
breast cancer risk may be increased in women using
DMPA when very young and particularly in recent users. Current knowledge of the biology of human
breast cancer is such that it is difficult to judge the
biological plausibility of this evidence. There is no doubt that
DMPA is a highly effective form of
contraception and any overall assessment must take into account all the relevant risks and benefits. Thus, the risk-benefit equations in developed and developing countries must allow for different levels of maternal mortality and morbidity, as well as differing underlying
cancer rates.