Older (age > 60 years) patients obtain survival benefit from herceptin plus chemotherapy

Anti-HER2 therapy for breast cancer in older patients

Older patients now form between 30 and 40% of breast cancer (BC) patients. Managing older patients with BC is particularly challenging due to the limited availability of high-quality evidence. In this review we discuss the available evidence on the efficacy and safety of anti-HER2 agents in older patients with HER2-positive BC is presented, with a particular look at the latest results of promising new agents such trastuzumab-deruxtecan. The data suggest that older patients can expect similar efficacy when using standard regimens, with higher toxicity, particular cardiac toxicity and diarrhea. Anti-HER2 agents should thus be used in most older patients most as per standard of care as long as adequate follow-up is available to manage toxicities.

Trastuzumab use in older patients with HER2-positive metastatic breast cancer: outcomes and treatment patterns in a whole-of-population Australian cohort (2003-2015)

Background

Older patients with HER2-positive metastatic breast (HER2 + MBC) cancer are underrepresented in clinical trials. We aim to describe the treatment patterns and overall survival (OS) for older women receiving trastuzumab for HER2 + MBC.

Methods

Retrospective, whole-of-population cohort study using demographic, dispensing, and medical services data for Australian women ≥ 65 years initiating trastuzumab for HER2 + MBC between 2003 and 2015. We describe time-on-trastuzumab; type and timing of other cancer treatments; rates of cardiac monitoring; and OS from trastuzumab initiation for HER2 + MBC.

Results

Of 5404 women initiating trastuzumab for HER2 + MBC, 1583 (29%) were ≥ 65 years old, and the proportion of older patients increased from 20% in 2003 to 38% in 2015. The median age for older women was 73 years and 516 (33%) were ≥ 75 years. Most older patients (92%) received ≥3medicines for comorbidities other than cancer. Median (IQR) time on trastuzumab was 14.1 months (5.9–32.1) and on all chemotherapy was 5.6 months (3.3–10.8). 74% received ≥1 chemotherapy agent and 56% received endocrine therapy. Half (49%) of patients had a cardiac assessment prior to initiating trastuzumab and overall 1228 (76%) had ≥1 cardiac assessment during the study period. At a median follow-up of 6 years, 73% of patients had died and the median OS was 25.6 months (IQR 10.7–58.7).

Conclusions

Older patients comprise a growing proportion of patients treated with HER2-targeted therapies in the real-world but they remain underrepresented in trials of these agents. Few trials report duration or OS estimates for older patients but our estimates are similar to those from trials that have. Although cardiac monitoring was a requirement of accessing trastuzumab during our study period, many patients did not undergo a cardiac assessment.

Targeted agents for HER2-positive breast cancer in older adults: current and future perspectives

INTRODUCTION

One-third of breast cancer (BC) cases worldwide occur in women aged 65 years and older, with 10 to 15% overexpressing the human epidermal growth factor receptor 2 (HER2). Although several HER2-targeted therapies have been developed, the lack of data regarding their use in older patients hampers evidence-based decision-making for this population.

AREAS COVERED

We review current evidence on the efficacy and safety of HER2-targeted therapies in older adults with BC, focusing on approved therapies such as trastuzumab, lapatinib, pertuzumab, ado-trastuzumab-emtansine, and neratinib. Additionally, we discuss drugs under development to target the HER2-receptor, and to overcome resistance to existing therapies. Finally, we highlight the cardiotoxicity of HER2-targeted drugs among older adults.

EXPERT OPINION

Older adults are underrepresented in trials of HER2-targeted therapies in BC. We propose strategies to increase recruitment of older adults in clinical trials in order to increase the evidence base to treat this growing population.