Pregnancy-associated breast cancer and pregnancy following treatment for breast cancer, in a cohort of women from Victoria, Australia, with a first diagnosis of invasive breast cancer

BACKGROUND: This study examined pregnancy-associated breast cancer (PABC) and pregnancy following treatment for breast cancer. METHODS: We analysed data from a questionnaire-based, prospective study of women diagnosed with breast cancer. Timing of diagnosis in relation to pregnancy was self-reported in the enrolment questionnaire. Women reported subsequent pregnancies in annual follow-up questionnaires, up to at least 5 years from diagnosis. RESULTS: Women with PABC made up 3.3% of women <48 years at diagnosis and 14.3% of women aged <35 years at diagnosis. Nine of 46 (19.6%) women who were aged <40 years at diagnosis, and had either no children, or only one child, became pregnant subsequent to their diagnosis, and 8 experienced a live birth. DISCUSSION: As the number of women with PABC was small, conclusions from this study are limited. However, young women should be alert to PABC, especially in the post-partum period. Some women, with incomplete families at diagnosis, are choosing to have one or more pregnancies following treatment.