Abstract
A consecutive series of 644 women who presented with breast nodularity between 1976 and 1982 have been followed up to determine their rate of subsequent breast cancer. Fifteen women have developed breast cancer, 14 of these were among 352 women with an aspirated cyst (relative risk 4.4). Women with multiple cysts had the highest risk and women with breast nodularity had no excess risk. Review of histology specimens from those women who had undergone biopsy showed an excess of florid epithelial hyperplasia in women who subsequently developed breast cancer and women with multiple aspirated cysts were more likely to have florid epithelial hyperplasia. Multiple cysts are clinical markers of histological breast proliferation and women who have had multiple breast cysts aspirated have an increased risk of breast cancer and should be advised to practice regular self examination.