Breast cancer treatment outcomes have steadily improved over the last 20 years. Results from randomised studies demonstrate the benefits of radiotherapy following breast conservation and post-mastectomy for selected patients. More recent international results demonstrate continued improvements in loco-regional control. The aim of this study was to determine recurrence rates in a contemporary Australian series and determine if local experience is in keeping with published benchmarks.
This was a retrospective analysis of all breast cancer patients treated with adjuvant radiotherapy in a large regional radiotherapy centre between the years of 2009-2011. Patients with DCIS and neoadjuvant treatment were excluded. All cases were individually reviewed. The 5 year risks of developing local recurrence (LR), loco-regional recurrence (LRR), distant metastases (DM), disease free survival (DFS) and overall survival (OS) were calculated using Kaplan-Meier statistics.
A total of 419 patients received adjuvant radiotherapy during the study period, with 338 courses of whole breast radiotherapy (WBRT) and 83 of post-mastectomy radiotherapy (PMRT). The average age was 60 with a median follow up of 54 months. PMRT patients had higher T and N stage. The 5 year rates of LR and DM following WBRT were 1.6% (CI 0-3.3) and 3.1% (CI 0.9-5.3) with the corresponding rates following PMRT being 2.6% (CI 0-7.4) and 22% (CI 8-34) (there were no isolated regional recurrences). The overall 5 year DFS and OS were 93% (CI 88-97) and 95% (CI 91-98) respectively.
These results provide local documentation of high loco-regional control rates for breast cancer in a contemporary series at relatively early follow up. These improved outcomes likely reflect improvement across diagnosis, surgery, pathology, systemic and local treatments.