Surgical clinical trials.

Surveys of surgical practice in the United States during the last 2 decades have documented a gradual retreat from the standard radical mastectomy for treatment of early breast cancer. During this time, clinical trials have tested traditional principles of cancer surgery, and permitted conclusions to be made regarding treatment alternatives. Modified mastectomy (total mastectomy plus axillary dissection) has proved equal to radical mastectomy in terms of survival, disease-free survival, and local tumor control in a randomized trial confined to TNM clinical Stage I and II cases. This study showed that routine removal of grossly uninvolved pectoral muscles (and apical axillary nodes) is not necessary in early cases, a result which failed to support the principle of en bloc dissection. Trials addressed to the practice of prophylactic regional node dissections have indicated that node dissections are useful for reducing regional tumor recurrence, for providing prognostic information, and for establishing the need for adjuvant treatment, but they do not improve overall survival. Metastases in lymph nodes appear to be a sign, rather than a source, of tumor dissemination. Furthermore, a recent trial indicates that routine removal of the breast may not be necessary in early cases. High-dose irradiation of the breast (after wide excision of the primary and axillary dissection) in TNM clinical Stage I cases provided local tumor control and survival comparable to that of radical mastectomy. Trials of breast preservation not yet complete address more advanced stages (TNM I and II), and the question of whether irradiation is necessary in all cases. On the basis of completed studies, it appears that TNM clinical State I and II cancers can be appropriately treated with modified mastectomy; Stage I cancers can be treated equally well with irradiation of the breast after quadrantectomy and removal of axillary lymph nodes.