Breast Cancer in Pregnancy and Lactation

Cancer of the breast is the most common malignancy in white women. Although the highest incidence is encountered in the older age groups, figures of between 15% and 25% have been reported for the child-bearing age group (15–45 years) (Haagensen, 1971; Donegan, 1972; Brunet et al, 1977). Breast cancer and pregnancy or lactation can obviously occur either synchronously or metachronously, which implies that these conditions may influence each other. Breast cancer detected during pregnancy or lactation may have been under the influence of this special hormonal milieu, while on the other hand a pregnancy can have an effect on any residual tumor after mastectomy.