Purpose In a previous retrospective audit from our institution, access to human epidermal growth factor receptor 2 (HER2) –targeted therapy (H2T) in patients registered and treated in 2008 was reported, wherein only 38 (8.61%) of 441 patients received some form of H2T. Three developments occurred in subsequent years that potentially affected access to H2T at our institution—that is, a patient access program supported by the innovator pharmaceutical company, a generous philanthropic donor, and the use of biosimilars. Methods To evaluate the cumulative impact of these developments on access to trastuzumab, we reviewed access to H2T in a recent cohort of patients with breast cancer registered in at our institution. Results In 2016, 4,717 new patients with breast cancer were registered at our institution. Among these patients, HER2 3+ expression by immunohistochemistry or fluorescent in situ hybridization (FISH) was reported in 828 patients (22.77%). Assuming the same 33.22% amplification rate in the 343 patients who did not undergo FISH testing, there were potentially 114 more patients with HER2-amplified tumors. Thus, the final number of HER2-overexpressing/-amplified tumors is estimated to be 942 in 2016 (729 HER2 immunohistochemistry 3+, 99 known FISH amplified, and 114 estimated FISH amplified). Of these 942 patients, 13 were not deemed suitable for H2T and 94 did not follow-up for additional treatment at our institution. The remaining 835 patients were eligible to receive H2T and were analyzed for access to this treatment. Overall, 444 (53.2%) of these 835 patients received trastuzumab for durations that ranged from 12 weeks to 12 months in the (neo)adjuvant setting or other durations in the metastatic setting. This is in contrast to the previously reported 8.61% use of H2T in the cohort of patients registered in 2008. Conclusion We suggest that other institutions, especially public hospitals that treat underprivileged patients, make concerted efforts to increase access to potentially curative treatments, such as trastuzumab, using targeted programs and philanthropic support, and consider using a shorter duration of 12 weeks of trastuzumab to improve patient outcomes. AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST The following represents disclosure information provided by authors of this manuscript. All relationships are considered compensated. Relationships are self-held unless noted. I = Immediate Family Member, Inst = My Institution. Relationships may not relate to the subject matter of this manuscript. For more information about ASCO's conflict of interest policy, please refer to www.asco.org/rwc or ascopubs.org/jco/site/ifc . No COIs from the authors.
Responses: Re: Treatment of Human Epidermal Growth Factor Receptor 2-Overexpressing Breast Cancer Xenografts With Multiagent Human Epidermal Growth Factor Receptor-Targeted Therapy