PracticeUpdate: Haematology & Oncology

CONFERENCE COVERAGE 14

HER2 therapy for early-stage breast cancer has altered presentation of HER2-positivemetastatic breast cancer T he introduction of HER2 therapy for early-stage breast cancer has altered the presentation of HER2-positive significantly (17% to 58%) over the same time interval. This increase was most likely an effect of the introduction of HER2 therapy for early-stage breast cancer. Such routine treatment began in 2005.

response received anti-HER2 therapy with chemotherapy, had fewer than two sites of metastatic disease, and had not been pretreated with HER2 therapy previously. Dr Gullo said that the introduction of HER2 therapy for early-stage breast cancer over a decade ago has altered the presentation of HER2-positive metastatic breast cancer significantly, with a larger proportion of patients now presenting with the de novo metastatic disease. Patients who present with de novo metastatic breast cancer and harbour fewer than two sites of metastatic disease are more likely to achieve prolonged overall survival and even sustained disease remission when treated with HER2 therapy in combination with chemotherapy. These clinical factors may be used to prognosticate patient outcome and can be incorporated into clinical trials of HER2 therapy.

metastatic breast cancer significantly over the past decade. Patients who present with de novo metastatic breast cancer and harbour fewer than two sites of metastatic disease are more likely to achieve prolonged overall survival when treated with HER2 therapy combined with chemotherapy. This observation was based on results of a retrospective, single-centre review. Giuseppe Gullo, MD, of St. Vincents University Hospital, Dublin, Ireland, explained that the introduction of anti- HER2 therapy has significantly improved the objective response rate and overall survival of patients with HER2-positive metastatic breast cancer. Though HER2-positive metastatic breast cancer remains incurable, a meaningful minority of patients on first-line HER2 therapy experience a prolonged phase of disease control. Clinical factors at presentation of metastatic breast cancer associated with overall survival, however, have not been fully elucidated and are not part of baseline patient assessment. Dr Gullo and colleagues analysed 134 consecutive patients with HER2-positive metastatic breast cancer treated between 2000 and 2016. Patient characteristics at initiation of HER2 therapy were: • Median age: 55 (range 25–83) years • Oestrogen or progesterone receptor positivity: n=76 (57%) • Oestrogen and progesterone receptor negativity: n=47 (35%) • Unknown oestrogen/progesterone receptor status: n=11 (8%) • Fewer than two metastatic sites: n=98 (73%) • More than two metastatic sites: n=36 (27%) • Visceral disease: n=85 (63%) • HER2 therapy + chemotherapy: n=116 (86%). Median follow-up duration was 23 months (range 0.3–193). The proportion of patients treated for relapsed HER2- positive metastatic breast cancer decreased significantly from 2000–2005 (83%) to 2011–2016 (relapsed metastatic breast cancer, 42%), whereas de novo HER2- positive metastatic breast cancer increased

Patients with de novo metastatic breast cancer experienced longer median overall survival (44 months [95% CI 29–84]) than those with relapsed metastatic breast cancer (38 months [95% CI 23–47]). Longer overall survival was significantly associated with fewer than two sites of metastatic disease (P = 0.015), the absence of visceral metastases (P = 0.048), and treatment with HER2 therapy in association with chemotherapy (P = 0.022). On multivariate analysis, de novo metastatic breast cancer (P = 0.048) and fewer than two metastatic sites at diagnosis (P = 0.001) were associated with significantly longer overall survival and reduced risk of death. Twenty-one patients (16%) achieved complete response, 16 who have not relapsed. All 16 patients with durable complete

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PRACTICEUPDATE HAEMATOLOGY & ONCOLOGY