The Breast Cancer Prevention Institute provides a compilation: Epidemiologic Studies: Induced Abortion and Breast Cancer Risk. There are 76 studies on the list with the earliest published in 1957. Of the 76 studies listed, 61 found a positive association between abortion and breast cancer. 41 of these were statistically significant. For more information, read:
bcpi-factsheet-epidemiol-studies_2020.pdf (bcpinstitute.org)
