[Five Cases of Breast Cancer Developed after Silicone Breast Implant]

We report 5 cases of breast cancer that developed after cosmetic augmentation using silicone breast implants. The chief complaints were breast tumor in 3 cases, skin change in 1 case, and nipple bleeding in 1 case. Intervals between silicone breast implants and breast cancer surgeries ranged from 10 to 31 years. The pTNM stages included were Stage 0, Ⅰ, ⅡA, ⅢB, and Ⅳ, respectively, and the subtypes included were 3 Luminal types and 2 Luminal-HER2 types. Silicone bag rupture was noted in 1 case, and all bags were removed during surgery. The breast cancer surgeries performed were four breast- conserving surgeries and one mastectomy. The follow-up period ranged between 1.8 and 14 years(mean 5.1 years). All cases survived, but 2 cases had recurrences; the Stage ⅢB case experienced lung metastasis 2 years postoperatively and Stage Ⅳ case had induced pCR by chemotherapy postoperatively, but therapeutic self-interruption led to recurrences at the contralateral axillary nodes and contralateral breast and lung metastases 3 years postoperatively. Judging from limited reports of breast cancer after silicone breast implant in Japan, their incidence seems to be extremely low, and the incidence in our clinic during these 15 years(5 out of 1,851 primary breast cancers)is 0.27%.