Clinical benefits of mastectomy on treatment of occult breast carcinoma presenting axillary metastases.

Occult breast carcinoma presenting axillary metastases is uncommon and accounts for less than 1% of newly diagnosed breast carcinoma. However, it continues to be a challenging diagnostic and therapeutic problem. In this study, we analyzed retrospectively on 51 cases of occult breast cancer from 1990 to 2003 in our hospital. All these patients had a palpable axillary nodule, no dominant breast mass, and no abnormal mammograms and breast ultrasonograph. Histological examination of axillary mass revealed metastasis from breast. The positive rate of estrogen receptor, progesterone receptor and the monoclonal antibody M4G3 against human breast cancer showed 62.7%, 66.7%, and 93.1% positive respectively. Among 51 cases, 38 cases received mastectomy whereas 13 cases had no local treatment of the breast. The primary tumors were detected in 28 of 38 cases having mastectomy by pathology. Seventy-seven percent of patients who had no local treatment of the breast had a tumor recurrence, compared with 26% who had a mastectomy. The mean disease-free survival was 23 months in patients who had no local treatment of the breast, compared with 76 months in patients who had mastectomy. Eight of the 13 patients who had no treatment with breast died whereas seven of the 38 who had local treatment died, with a mean follow-up of 73 months. It was found that patients having mastectomy had a better disease-free survival (p < 0.001) and overall survival (p < 0.001) compared with those having no local treatment of the breast. Once the diagnosis of occult breast carcinoma is clarified, an axillary dissection and the local treatment of breast should be carried out.