Isolated loco-regional recurrence of breast cancer is more common in young patients and following breast conserving therapy: Long-term results of European Organisation for Research and Treatment of Cancer studies

The aim of this study was to evaluate prognostic factors for isolated loco-regional recurrence in patients treated for invasive stage I or II breast cancer. The study population comprised 3602 women who had undergone primary surgery for early stage breast cancer, who were enrolled in European Organisation for Research and Treatment of Cancer (EORTC) trials 10 801, 10 854, or 10 902, by breast conservation (55%) and mastectomy (45%). The median follow-up time varied from 5.3 (range: 0.6–9.5) to 11.9 years (range: 0.6–17.4). Main outcome was the occurrence of isolated loco-regional recurrence. The results of multivariate analysis showed that younger age and breast conservation were risk factors for isolated loco-regional recurrence (breast cancer under 35 years of age versus over 50 years of age: hazard ratio 2.80 (95% CI 1.41–5.60)); breast cancer age 35–50 years versus over 50 years: hazard ratio 1.72 (95% CI 1.17–2.54); breast conservation (hazard ratio: 1.82 (95% CI 1.17–2.86)). After perioperative chemotherapy, less isolated loco-regional recurrences were observed (hazard ratio 0.63 (95% CI 0.44–0.91)). No significant interaction effects were observed. It is concluded that young age and breast conserving therapy are both independent predictors for isolated loco-regional recurrence. As an isolated loco-regional recurrence is a potentially curable condition, women treated with breast conservation or diagnosed with breast cancer at a young age should be monitored closely to detect local recurrence at an early stage.