Determinants of axillary recurrence after axillary lymph node dissection for invasive breast cancer

Aim: This study was undertaken to gain insight into the risk factors for ax illary recurrence among patients with invasive breast cancer who underwent breast-conserving treatment or mastectomy and axillary lymph node dissectio n. Methods: In a matched case-control design, 59 patients with axillary recurr ence and 295 randomly selected control patients without axillary recurrence were compared. Matching factors included age, year of incidence of the pri mary tumour and postsurgical axillary nodal status. Results: For patients with negative axillary lymph nodes, those with a tumo ur in the medial part of the breast had a 73% (95% CI: 4-92%) lower risk of axillary recurrence compared to those with a tumour in the lateral part of the breast. For the patients with positive axillary lymph nodes the risk o f axillary recurrence was 65% (95% CI: 16-86%) lower for those who had rece ived axillary irradiation compared to those without axillary irradiation. W ithin the age group <50 years, the risk or axillary recurrence was 82% lowe r (95% CI: 45-94%) for patients with more than six lymph nodes found in the axillary specimen compared to those with six or less than six lymph nodes. Conclusions: Although based on a small number of patients, this study indic ates that axillary irradiation is effective in reducing the risk of axillar y recurrence for patients with positive lymph nodes. This favourable effect only applies to the subgroup with extranodal extension or nodal involvemen t in the apex of the axilla, as these were the only patients receiving axil lary radiation during the study period. (C) 2001 Harcourt Publishers Ltd.