Long-term outcome in patients with four or more positive lymph nodes treated with conservative surgery and radiation therapy

Abstract

The purpose of this study was to review management strategies with respect to systemic therapy, radiation therapy treatment techniques, and patient outcome (local regional control, distant metastases, and overall survival) in patients undergoing conservative surgery and radiation therapy (CS + RT) who had four or more lymph nodes involved at the time of original diagnosis. Of 1040 patients undergoing CS + RT at our institution prior to December 1989, 579 patients underwent axillary lymph node dissection. Of those patients undergoing axillary lymph node dissection, 167 had positive nodes and 51 of these patients had four or more positive lymph nodes involved and serve as the patient population base for this study. All patients received radiation therapy to the intact breast using tangential fields with subsequent electron beam boost to the tumor bed to a total median dose of 64 Gy. The majority of patients received regional nodal irradiation as follows: 40 patients received RT to the supraclavicular region without axilla to a median dose of 46 Gy, 10 patients received radiation to the supraclavicular region and axilla to a median dose of 46 Gy. Thirty of the 51 patients received a separate internal mammary port with a mixed beam of photons and electrons. One patient received radiation to the tangents alone without regional nodal irradiation. Adjuvant systemic therapy was used in 49 of the 51 patients (96%) with 27 patients receiving chemotherapy alone, 14 patients receiving cytotoxic chemotherapy and tamoxifen, and 8 patients receiving tamoxifen alone. As of December 1994, with a minimum evaluable follow-up of 5 years and a median follow-up of 9.29 years, there have been 18 distant relapses, 2 nodal relapses, and 5 breast relapses. Actuarial statistics reveal a 10-year distant metastases-free rate of 65%, 10-year nodal recurrence-free rate of 96%, and a 10-year breast recurrence-free rate of 82%. All five patients who sustained a breast relapse were successfully salvaged with mastectomy. Both patients with nodal relapses (one supraclavicular and one axillary/supraclavicular) failed within the irradiated volume. Of the 40 patients treated to the supraclavicular fossa (omitting complete axillary radiation), none failed in the dissected axilla. With a median follow-up of nearly 10 years, 29 of the 51 patients (57%) remain alive without evidence of disease, 15 (29%) have died with disease, 2 (4%) remain alive with disease, and 5 (10%) have died without evidence of disease. Overall actuarial 10-year survival for these 51 patients is 58%. We conclude that in patients found to have four or more positive lymph nodes at the time of axillary lymph node dissection, conservative surgery followed by radiation therapy to the intact breast with appropriate adjuvant systemic therapy results in a reasonable long-term survival with a high rate of local regional control. Omission of axillary radiation in this subset of patients appears appropriate because there were no axillary failures among the 41 dissected but unirradiated axillae.