Oral Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2017

Patterns of care and outcomes for long-term survivors with HER2-positive metastatic breast cancer (HER2+MBC) starting trastuzumab: an Australian whole-of-population cohort study (#91)

Benjamin Daniels 1 , Sarah J Lord 2 3 , Belinda E Kiely 2 , Nehmat Houssami 4 , Sallie-Anne Pearson 1
  1. Medicines Policy Research Group, Centre for Big Data Research in Health, University of New South Wales, Kensington, NSW, Australia
  2. NHMRC Clinical Trials Centre, Sydney Medical School, University of Sydney, Camperdown, NSW, Australia
  3. School of Medicine, University of Notre Dame Australia, Sydney, NSW, Australia
  4. School of Public Health, University of Sydney, Camperdown, NSW, Australia


Women with HER2+MBC are living longer but little is known about their long-term treatment patterns and survival. We describe the demographics, treatment characteristics, and overall survival (OS) for an Australian cohort of long-term survivors with HER2+MBC.


We used Herceptin Program dispensing records to identify women surviving ≥5 years from initiation of trastuzumab for MBC. We used Kaplan-Meier methods to estimate time-on-trastuzumab (from first dispensing date until last dispensing, plus 30 days) and OS (time from first trastuzumab dispensing until death or last date alive). We defined a break of ≥90 days between trastuzumab dispensings as a separate treatment course. We used dispensing records to determine the type and duration of additional cancer treatments.


We identified 1,082 women surviving ≥5 years from first dispensing of trastuzumab: 26% of all trastuzumab-treated patients between 2001-2011. Median age (interquartile range [IQR]) at initiation was 54 years (46–63). Median time-on-trastuzumab was 4.9 years (2.3–7.4); time on chemotherapy 1.2 years (0.4 – 3.5); and time on endocrine therapy 4.8 years (1.9 – 9.6). 333 women (31%) received at least one other HER2-targeted therapy. 655 patients (61%) had >1 break in trastuzumab therapy with a median break duration of 0.9 years (0.3 – 4.3), and 317 (29%) received <2.5 years of trastuzumab during the first 5 years. Median OS was 11.6 years (7.0–not reached).


Our findings provide population-based estimates of the 5-year survival rate and median durations of therapy and OS for long-term surviving HER2+MBC patients treated with trastuzumab. With the availability of new and effective HER2-targeted therapies the number of long-term survivors is likely to increase and these data are potentially useful for treating oncologists and for policy makers from the perspective of resource use and costs.