Long-term follow-up of axillary node-positive breast cancer patients receiving adjuvant tamoxifen alone: patterns of recurrence

Abstract

Purpose: To determine the patterns, incidence and risk factors for local-regional recurrence in patients with Stage II and III breast cancer treated with adjuvant tamoxifen alone, without adjuvant radiation. Material and Methods: The records of patients referred to the London Regional Cancer Centre with a diagnosis of breast cancer between 1980–1989 were reviewed. During this time period, it was the policy of the institution to omit local-regional radiation to patients receiving adjuvant systemic therapy. One hundred and fifty axillary node-positive Stage II and III breast cancer patients received adjuvant tamoxifen alone without postoperative local-regional radiation; these patients form the basis of this report. Results: Median follow-up was 67 months for the entire patient group and 85 months for the living patients. During this time, 42% of patients developed a recurrence, 22% first recurred in local-regional sites. The total incidence of local-regional recurrence (including those patients who first relapsed with systemic metastases) was 30%. Of the segmental mastectomy patients, 13% had recurrences in the intact breast. Of the modified radical mastectomy patients, 10% developed chest wall recurrences. Five percent of recurrences were first in the axilla and 6% in the supraclavicular nodes. Five-year actuarial survival for the entire patient group was 79% and disease-free survival was 60%, with a median disease-free survival time of 87 months. Five-year local-regional relapse-free survival was 76%. Five-year local-regional relapse-free survival was < 76% for those patients with 4 or more positive axillary nodes, regardless of tumor size. On univariable analysis, positive resection margins, number of positive axillary nodes, menopausal status, and negative estrogen and progesterone receptors were significant for isolated local-regional recurrence. On multivariable analysis, only positive resection margins and negative receptors remained significant. In terms of regional recurrence specifically, negative estrogen and progesterone-receptor status and positive resection margins were, again, prognostically significant. Conclusions: Postmenopausal women receiving adjuvant tamoxifen who have positive resection margins, ≥ 4 positive axillary nodes and/or negative estrogen and progesterone receptors, are at higher risk of local and regional recurrence and should, therefore, receive local-regional radiation.