Many studies, indicating not only correlation but causation, and at least one major meta-analysis indicating a very significant increase in cancer risk following abortion.
That was the part I found so difficult to reconcile, and I had applauded Komen's cutting off Planned Parenthood funding.
It is a pity they did not bring out those studies and use them as the reason they cut off funding--something which might have been a great service to the very women they claimed to want to help.