To the Editor.
—In their article on the association between breast cancer and abortion, Dr Newcomb and colleagues1 indicated awareness of the existence of underreporting of induced abortion in retrospective studies and of the possibility that women who have breast cancer might be more accurate in reporting their abortion histories than women who do not have cancer. However, the underreporting of induced abortion in their study may have been greater than they realized.Using data collected by the Alan Guttmacher Institute2 and the Centers for Disease Control and Prevention,3 we estimate that 25% of females aged 15 through 44 years in 1989 had 1 or more induced abortions at sometime in their life. Although this percentage varies with age, it is a reasonable estimate for women younger than 45 years in the study by Newcomb et al. For women aged 45 years and older, most of whose
Henshaw SK. Pregnancy Termination and Risk of Breast Cancer. JAMA. 1996;276(1):31. doi:10.1001/jama.1996.03540010033023