Consequences of axillary recurrence after conservative breast surgery

Abstract
Background The aim was to study the incidence, time course and prognosis of patients who developed axillary recurrence after breast-conserving surgery, and to evaluate possible risk factors for axillary recurrence and prognostic factors after axillary recurrence. Methods In a population-based cohort of 6613 women with invasive breast cancer who had breast-conserving surgery between 1981 and 1990, 92 recurrences in the ipsilateral axilla were identified. Risk factors for axillary recurrence were studied in a case–control study nested in the cohort, and late survival was documented in the women with axillary recurrence. Results The overall risk of axillary recurrence was 1·0 per cent at 5 years and 1·7 per cent at 10 years. The risk of axillary recurrence increased with tumour size (P = 0·033) and was highest in younger women (odds ratio (OR) 3·9 for women aged less than 40 years compared with those aged 50–59 years). Radiotherapy to the breast reduced the risk of axillary recurrence (OR 0·1 (95 per cent confidence interval 0·1 to 0·4)). The breast cancer-specific survival rate after axillary recurrence, as measured from primary treatment, was 78·0 per cent at 5 years and 52·3 per cent at 10 years. Tumour size and node status had a statistically significant effect on death from breast cancer. Conclusion Axillary recurrence is rare, although more common in younger women with large tumours. Radiotherapy to the breast was protective. Tumour size and node status were the most important prognostic factors in women with axillary recurrence.