Women with breast cancer often are advised to wait two years or longer after treatment before trying to become pregnant. This guideline, based solely on anecdotal evidence, attempts to deter women who may have an early recurrence and also to permit the completion of adjuvant treatment. There are no published data suggesting that postponing conception will alter the outcome of either the cancer or the pregnancy. This population-based descriptive study enrolled women 15 to 44 years of age, living in Western Australia, who received a diagnosis of breast cancer and subsequently became pregnant. Of 2539 women with pathologically confirmed breast cancer, presenting in the years 1982-2000, 123 (5%) had at least one pregnancy after being diagnosed.
Sixty-two of the women who conceived after breast cancer was diagnosed (54%) did so within 2 years after diagnosis. Twenty-nine of them had an abortion, 27 bore a live child, and 6 miscarried. Most of the women in this study had breast-conserving surgery. Only 6% of the group took tamoxifen. Proportional hazards regression analysis showed that subsequent pregnancy was associated with improved overall survival. The hazard ratio (HR) was 0.59, with a 95% confidence interval (CI) of 0.37-0.95. Overall survival improved in women who waited at least 2 years to conceive (HR, 0.48; 95% CI, 0.27-0.83). A protective effect also was suggested in women waiting at least 6 months to conceive, but it was not statistically significant.
These findings do not support a policy of recommending that premenopausal women with a diagnosis of breast cancer—at least those with localized disease and a good prognosis—wait two years before attempting to conceive a child. Such a recommendation may be appropriate for women receiving treatment and those having systemic disease at the time of diagnosis.