Pathologic features, clinical outcomes, and treatment patterns of early-stage triple-negative (TN) breast cancer in an Australian population.

Abstract

e11102 Background: TN breast cancers are associated with young onset, high-risk pathology, distant metastases and poor prognosis. We examined pathological features, treatment and clinical outcomes of patients (pts) with early-stage TN breast cancer in an Australian population. Methods: Data on pt age, histopathology, treatment and survival outcomes was collected from the pathology database and medical records for 86 pts with histologically confirmed early-stage TN breast cancer resected at Austin Hospital and Northern Hospital (January 1, 2001-February 28, 2009). Results: Mean age at diagnosis was 59 years (y) (range 27-98; SD 15.6); 70% pts were ≥ 50 y. Mean tumour size was 27 mm (range 5-70). Disease stage was I in 26%, II in 61% and III in 13%. 85% were BRE grade 3. 89% pts had ductal carcinoma; the remaining were: atypical medullary (6%), adenoid cystic (2%), lobular (1%) and papillary (1%). Lymphovascular invasion and necrosis were present in 31% and 39% of tumors, respectively. 60% (51/85) had wide local excision (WLE) and 40% (34/85) total mastectomy. 80% (69/86) received adjuvant chemotherapy (CT): 54% (37/69) anthracyline- based, 38% (26/69) taxane-based, and 9% (6/69) other CT. Of the 17 pts not given CT, 11 were unfit, 3 declined and 3 not offered. There was a negative association between age at diagnosis and receiving CT (p < 0.001). 74% (64/86) had adjuvant radiotherapy (RT). During a median follow-up of 28.6 months (m) (range 0.3-120; SD 27.6), 24 pts (28%) had any relapse - 11 locoregional, 18 distant (5 both). For any relapse, disease stage: I in 26%, II in 61% and III in 13%. Median times to any, locoregional and distant relapses were 21.8 m, 33.4 m and 18.6 m, respectively. Sites of distant recurrence were (in descending frequency) lung, bone, brain and others. There were 21 (24%) deaths (median time to death 17 m). Median overall and disease-free survival were 87.8 m and 80.5 m. Conclusions: The majority of TN pts were ≥ 50 y. Most tumors were stage II, high grade and of ductal pathology. Most pts had WLE, adjuvant CT (most commonly anthracycline-based) and RT. Distant relapse was earlier and more common than locoregional, most often in the lung. No significant financial relationships to disclose.