Patterns of Care and Clinical Outcomes of First-Line Trastuzumab-Based Therapy in HER2-Positive Metastatic Breast Cancer Patients Relapsing After (Neo)Adjuvant Trastuzumab: An Italian Multicenter Retrospective Cohort Study

Abstract

Background. We evaluated the patterns of care and clinical outcomes of metastatic breast cancer patientstreated with firstline trastuzumab-based therapy after previous (neo)adjuvant trastuzumab. Materials and Methods. A total of 416 consecutive, HER2-positive metastatic breast cancer patients who had received first-linetrastuzumab-basedtherapywereidentifiedat14Italian centers. A total of 113 patients had presented with de novo stage IV disease and were analyzed separately. Dichotomous clinical outcomes were analyzed using logistic regression and time-to-event outcomes using Cox proportional hazards models. Results. In the 202 trastuzumab-naïve patients and 101 patients with previous trastuzumab exposure, we observed the following outcomes, respectively: overall response rate, 69.9% versus 61.3% (adjusted odds ratio [OR], 0.62; p 5 .131), clinical benefit rate, 79.1% versus 72.5% (adjusted OR, 0.73; p 5 .370), median progression-free survival (PFS), 16.1

Outcomes of re-treatment with first-line trastuzumab plus a taxane in HER2 positive metastatic breast cancer patients after (neo)adjuvant trastuzumab: A prospective multicenter study

“…For re-treatment with first-line trastuzumab in patients previously treated trastuzumab, two retrospective [17, 18] and one prospective studies [19] have all shown effectiveness. The prospective study with trastuzumab in combination with docetaxel or paclitaxel by Lang et al showed a median PFS of 8.0 months, OS of 25.0 months in 41 patients after a 40-month median follow-up time [19], similar to our results.…”

“…The prospective study with trastuzumab in combination with docetaxel or paclitaxel by Lang et al showed a median PFS of 8.0 months, OS of 25.0 months in 41 patients after a 40-month median follow-up time [19], similar to our results. In the Italian multicenter retrospective cohort study of HER2-positive mBC, trastuzumab re-treatment of patients relapsing from previous (neo)adjuvant trastuzumab therapy showed a PFS of 12.0, ORR of 61.3%, CBR of 72.5%, and OS of 48.2 months [17]. In the retrospective study, trastuzumab as first-line therapy for HER2-positive mBC in patients previously treated with adjuvant trastuzumab showed a two-year OS of 60.0% [18].…”

“…However, the eligible patients in most of the trials studying the above anti-cancer agents were trastuzumab-naïve, thus their clinical outcomes in patients who develop recurrent disease from (neo)adjuvant trastuzumab setting are still largely unknown. Increasing evidence reported the effectiveness of continuous blockade of HER2 by trastuzumab, including two retrospective studies which have shown the efficacy of re-treatment regimen with trastuzumab in HER2-positive breast cancer, reporting an OS of 48.2 months [17] and two-year OS rate of 60.0% [18]. Re-treatment after Herceptin Adjuvant Trial reported with a median progression free survival (PFS) of 8.0 months and overall survival of 25.0 months in HER2-positive mBC patients relapsed after adjuvant trastuzumab [19].…”

First-Line Palliative HER2-Targeted Therapy in HER2-Positive Metastatic Breast Cancer Is Less Effective After Previous Adjuvant Trastuzumab-Based Therapy

“…Patients in the TN‐group had either relapsed after stage I–III primary breast cancer or presented with de novo stage IV disease. Because previous studies reported that the presentation with primary metastatic disease does not affect long‐term outcomes, these patients were pooled . The retrospective review of electronic patient records for the purpose of this study was approved by the central ethical review board (METC 15‐046) in addition to the permission of omitting written informed consent.…”

“…A possible way to study this might be comparing long‐term outcome between patients pretreated with trastuzumab and patients without previous trastuzumab. However, studies investigating this issue have shown conflicting results , possibly due to small numbers of patients , low numbers of events , or short duration of follow‐up . We have therefore performed a retrospective study to compare the efficacy of first‐line HER2‐targeted‐containing chemotherapy between patients who did or did not undergo adjuvant trastuzumab‐based treatment in a large number of patients, determined by a power analysis calculated prior to the start of the study, thereby guaranteeing a sufficient number of events (deaths).…”