Breast cancer subtypes and outcome after local and regional relapse.

BACKGROUND To evaluate the outcome of breast cancer patients after locoregional recurrence (LRR) according to tumor biological features evaluated at first diagnosis and at the time of recurrence. PATIENTS AND METHODS We collected information on all consecutive breast cancer patients operated at the European Institute of Oncology between 1994 and 2005. The tumor characteristics and subsequent outcome of patients who experienced LRR were analyzed. RESULTS Two hundred and seventy nine patients with LRR were identified, 197 and 82 patients with local and regional recurrence respectively. The overall discordance rate between primary cancer and LRR was 9% for estrogen receptor expression, 22% for progesterone receptor and 4% for human epidermal growth factor receptor 2. For patients with regional recurrence, the risk of distant metastasis was significantly higher compared with local relapse in case of late recurrence (hazard ratio [HR] = 2.76; 95% CI 1.31-5.85). Patients with triple-negative breast cancer at LRR experienced a higher risk of subsequent relapse (HR 2.87 [1.67-4.91]) and death (HR 2.00 [1.25-3.19]). CONCLUSION LRR correlates with a high risk of subsequent events and death in particular in patients with triple-negative subtype.