Risk of breast cancer in Japanese women with benign breast disease

To investigate the risk of breast cancer development in women with benign b reast disease (BBD), 387 screen-detected BED women and 1,489 normal women, taken from participants In the breast cancer screening program during 1978- 1986, were followed through 1991, While 2,811 person-years in the BED group and 11,018 person-gears in the normal group were accumulated, 5 women in t he BED group and 6 women in the normal group de, eloped breast cancer. Usin g the Mantel-Haenszel method, relative risks (RR) were estimated for all wo men with BED and,women in some BED types, Significantly elevated risk of br east cancer,vas observed in all women with BED (RR=3.26, 95% confidence int erval (Cl) 1.08-9.83). Women with proliferative BED were at high risk of br east cancer (RR=8.48, 95%Cl 2.99-24.10), but no increased risk was observed for women with non-proliferative BED (RR=0.93, 95%CL 0.11-7.66). These res ults are consistent With those in high-risk countries for breast cancer. In the management of women with BED, histopathological diagnosis of the breas t lesion is essential and women with proliferative BED should be followed u p carefully.