Cancer cell emboli in the pectoral lymphatics of patients with breast cancer.

In order to investigate the possibility of local recurrence in the pectoral muscles of patients who undergo modified radical mastectomies, the cancer cell involvement of the lymphatics associated with the pectoralis major muscle was studied in 39 patients who underwent a standard radical mastectomy for Stage I-III breast cancer. Cancer cell emboli were found in the transpectoral lymphatics of 2 patients (2/39 = 5.1 per cent) and in the pectoral fascial lymphatics of 6 patients (6/39 = 15.4 per cent). Two patients with fascial lymphatic cancer cell emboli were from a group of 14 patients with intramammary lymphatic tumor emboli of a low degree (ly 1). The other 6 patients with cancer cell emboli in either the pectoral fascia or the transpectoral lymphatics were from a group of 11 patients with intramammary lymphatic tumor emboli of a moderate degree (ly 2). There was a significant relationship between the intramammary and the pectoral lymphatic cancer cell emboli (Chi square test: (p less than 0.05). The results of this study therefore indicate that lymphatic cancer cell emboli in the pectoral fascia and muscle are an important risk factor for patients who undergo a modified radical mastectomy.