Breast Conservation Effective in Occult Primary Cancer With Axillary Metastases

WASHINGTON—Mastectomy does not improve either survival or local control when patients present with axillary node metastases and an occult primary tumor, Georges Vlastos, MD, of Geneva University Hospital, Geneva, Switzerland, said at the 54th Annual Cancer Symposium of the Society of Surgical Oncology. He described a retrospective study of 45 women with this rare condition, conducted when he was at M. D. Anderson Cancer Center.

Treatment remains controversial when the primary carcinoma is unknown in patients with axillary metastases, Dr. Vlastos said. First described by Halstead in 1907, this condition affects only 1% of all cases, he said, and only 400 such cases appear in the literature.

Mastectomy was formerly the treatment of choice, but breast preservation plus chemotherapy is now gaining attention as an alternative, he stated, noting that the unknown primary disease may occur outside the breast.

45 With Unknown Primary

A register compiled from 1951 to 1998 contained 479 women initially registered as having axillary metastases and unknown primary. Diagnostic workups that included mammogram, however, had eliminated all but 45, whose clinical and pathologic histories were reviewed.

Of these 45 patients, 71% presented with N1 clinical nodal status and the remainder with N2. Ages ranged from 32 to 79 years (median, 54). Modified radical mastectomy was performed in 13 patients, while the remainder were treated with the intent to preserve the breast. Seventy-one percent received locoregional radiotherapy, and 75% received systemic chemotherapy.

When the Kaplan-Meier method was used to calculate survival from the date of first diagnosis, the mastectomy and nonmastectomy groups showed identical overall and disease-free survival, Dr. Vlastos reported.

Only the number of positive nodes predicted survival, he added. Five-year survival for those with 1 to 3 positive nodes was 87% but only 42% for those with 3 or more.

Only One Primary Breast Cancer

Only one of the 13 patients who had undergone mastectomy proved to have a primary breast cancer in the tissue removed. Two others later were shown to have lung cancer and one to have neuroendocrine cancer.

Dr. Vlastos observed that the mastectomy and non-mastectomy patients probably represented different populations, the former being women treated in the 1950s and 1960s.