Immunohistochemical characteristics of human milk-fat globule antibodies in predicting chest wall and distant metastasis after mastectomy for localized cancer of the breast.

Because postoperative radiation reduces chest wall metastasis after mastectomy, it is important to identify patients in whom it might develop. Pathologic and immunohistochemical features in 59 patients with chest wall metastasis were compared with characteristics in disease-free patients and patients with systemic metastases without chest wall metastasis. Immunohistochemical studies with human milk-fat globule (HMFG)-2 were not predictive, but a membrane reaction with HMFG-1 was associated with fewer systemic metastases and tumors, in which most of the cells reacted with the antibody had significantly decreased likelihood of chest wall metastasis. Antigenic concordance between the primary breast cancer and the chest wall metastasis was demonstrated. Neither tumor size nor axillary node metastasis predicted development of chest wall metastasis, but systemic metastases were less common when fewer than four nodes were involved, the primary tumor was well differentiated, and estrogen receptors were positive.