Long-term tumor remission under trastuzumab treatment for HER2 positive metastatic breast cancer – results from the HER-OS patient registry

Abstract

BackgroundIn this study, we examined patients who had non-progressive disease for at least 2 years after diagnosis of inoperable locoregional recurrent or metastatic breast cancer under continuous trastuzumab treatment. Our primary goal was to assess the long-term outcome of patients with durable response to trastuzumab.Methods268 patients with HER2-positive inoperable locally recurrent or metastatic breast cancer and non-progressive disease for at least 2 years under trastuzumab treatment were documented retrospectively or prospectively in the HER-OS registry, an online documentation tool, between December 2006 and September 2010 by 71 German oncology centers. The study end point was time to tumor progression.ResultsOverall, 47.1% of patients (95% confidence interval (CI): 39.9–54.1%) remained in remission for more than 5 years, while the median time to progression was 4.5 years (95% CI: 4.0–6.6 years). Lower age (<50 years) and good performance status (ECOG 0) at time of trastuzumab treatment initiation as well as complete remission after initial trastuzumab treatment were associated with longer time to progression. Interruption of trastuzumab therapy correlated with shorter time to progression.ConclusionsHER2-positive patients, who initially respond to palliative treatment with trastuzumab, can achieve a long-term tumor remission of several years.

Long‑responders to anti‑HER2 therapies: A�case�report and review of the literature

“…On the contrary, the analysis conducted by Witzel et al (18) found that interruption of Trastuzumab in complete responder patients was associated with shorter TTP (P=0.0005).…”

“…Similarly, Witzel et al (18) analyzed patients with non-progressive disease for at least 2 years after diagnosis of inoperable locally recurrent or MBC under continuous Trastuzumab therapy. Data were collected by the HER-OS database, a German online documentation platform for patients with advanced HER2-positive.…”

Duration of Trastuzumab in Patients with HER2-Positive Metastatic Breast Cancer in Prolonged Remission

“…A few published studies and case reports in the literature have, because of late relapses, cautioned oncologists about discontinuing maintenance trastuzumab even after 2-3 years in remission 7,11 . In 2007, Beda et al 11 published a case report describing a patient with her2-positive mbc in complete remission for 2 years who relapsed soon after discontinuation of trastuzumab maintenance therapy.…”

“…Although some institutional guidelines 13 advocate 5 years of maintenance trastuzumab therapy, the effectiveness of that approach is still unknown. In 2014, Witzel et al 7 used results from the her-os registry to describe a cohort of patients who benefited from a longer duration of trastuzumab maintenance therapy. Yet, to date, no clear consensus on the duration of trastuzumab maintenance therapy in this patient population has emerged 6,14 .…”

“…23 Unfortunately, a large proportion of patients with her2-positive mbc treated with trastuzumab relapse after 12-24 months 7 . Nevertheless, a small proportion of her2-positive mbc patients remain in prolonged complete remission on trastuzumab maintenance therapy.…”