Pattern of relapse after breast conserving therapy, a study of 1519 early breast cancer patients treated in the Central Region of Denmark 2000–2009

Abstract

Background: The continuous improvements in diagnosing and treatment of breast cancer are reflected in the ever changing pattern of recurrence. The aim of the study was to investigating recurrence pattern and prognostic factors of recurrence in a population-based cohort.

Material and method: In total 1519 consecutive patients treated with breast conserving therapy (BCT) for invasive carcinoma between 2000 and 2009 in the Central Region of Denmark was included. Patients received adjuvant irradiation and systemic treatment according to the guidelines of the Danish Breast Cancer Cooperative Group, including boost for young women and those with a narrow margin.

Results: Median follow-up was 5.3 years (range 0.3–14.4). In total 183 women experienced breast cancer recurrence, 44 ipsilateral breast cancer recurrence, 13 regional recurrences, and 126 distant metastasis (DM). This corresponds to a cumulative risk of DM as first event at five and nine years of 6.5% and 12.6%, respectively. Further 42 women developed breast cancer in the contralateral breast. Disease-free survival (DFS) at five and nine years was 88% and 76%, respectively. Large tumor size (>20 mm), lymph node involvement, and vascular invasion were significantly associated with increased risk of DM. Margin width and age were not associated with risk of DM.

Conclusion: Acceptable recurrence rates and DFS were observed. Patients with large tumors, lymph node involvement, and vascular invasion had an increased risk of DM.