Locoregional recurrence risks in elderly breast cancer patients treated with mastectomy without adjuvant radiotherapy

This study examined tumour and treatment characteristics in elderly women treated with mastectomy without radiotherapy and compared their outcomes to younger counterparts. Data were analysed for 2362 women aged 50 years and older referred to the British Columbia Cancer Agency, Canada between 1989 and 1997. The women had invasive T1-4, N0-N3, M0 breast cancer treated with mastectomy without adjuvant radiotherapy. Clinical characteristics and patient outcomes were compared between two age cohorts: 50-69 (n = 1423) and 70+ years (n = 939). Median follow-up was 8.3 years. Tumours > 5 cm were present in 5% of women aged 50-69 and 3.5% of women aged 70+, respectively. The distribution of nodal stage was similar in the two age cohorts but older women were more likely to have fewer axillary nodes removed (P = 0.009). Fewer women aged 70+ had grade III histology (P = 0.002) and estrogen receptor (ER)-negative status (P < 0.001). The rates of systemic therapy use were comparable in the two age groups. With tumours > 5 cm, locoregional recurrence (LRR) were 13.7% and 30.0% in women aged 50-69 and 70+, respectively. With 1-3 positive nodes (N+), LRR were 14.8% and 13.0% in women aged 50-69 and 70+. In the presence of 4 N+, LRR were 16.8% and 30.8% in women aged 50-69 and 70+. On multivariate analysis, age was not significantly associated with LRR (P = 0.62). Independent prognostic factors for LRR were grade III histology, lymphovascular invasion and positive nodal status. This study suggests that despite more favourable tumour characteristics and comparable systemic therapy use, women aged 70+ years have similar or higher postmastectomy LRR risks compared to younger women. Chronologic age alone should not preclude these women from consideration of adjuvant radiotherapy.