As usual, pro-lifers and pro-choicers promote different beliefs
about a possible Abortion-Breast Cancer (ABC) linkage:
Most pro-life groups assert that an ABC link exists; i.e. that if
a woman has an abortion, her chance of contracting breast cancer
increases. 1 They rely
primarily on the results of case-control studies which are known to
be heavily biased and unreliable.
Most pro-choice groups state that an ABC link either does not exist, or
is unproven. 2 They rely primarily on cohort studies which are known to be much more reliable
Most anti-cancer health-promotion groups believe that an ABC link has not been proven to exist.
The best studies, cohort studies, all report no link, at least for
the 90% of abortions that are performed during the first trimester. One Danish
study reported in 1997 found that a link might possibly exist for very late-term abortions; however the
conclusion is not statistically significant. A much larger subsequent worldwide
meta-study confirmed that no ABC link exists.