Continuation of Trastuzumab Beyond Disease Progression Is Feasible and Safe in Patients with Metastatic Breast Cancer: A Retrospective Analysis of 80 Cases by the Hellenic Cooperative Oncology Group

Outcome of Patients with HER2-Positive Advanced Breast Cancer Progressing During Trastuzumab-Based Therapy

“…Those studies included patients who had received at least two subsequent trastuzumab-based regimens for metastatic disease. Fountzilas et al [10] described the clinical outcome of 80 patients continuing trastuzumab beyond disease progression in combination with additional chemotherapy. The first postprogression treatment resulted in a 24% response rate and a median progression-free survival duration of 5.2 months, but tumor responses were also seen with subsequent trastuzumab-based lines of treatment [10].…”

“…Fountzilas et al [10] described the clinical outcome of 80 patients continuing trastuzumab beyond disease progression in combination with additional chemotherapy. The first postprogression treatment resulted in a 24% response rate and a median progression-free survival duration of 5.2 months, but tumor responses were also seen with subsequent trastuzumab-based lines of treatment [10]. In a similar retrospective analysis conducted in 105 patients, Gelmon et al [9] reported a 32% response rate and a median progression-free survival of 24-30.5 weeks when either trastuzumab alone or combined with chemotherapy was administered as second- The Oncologist ® line treatment after failure of an initial trastuzumab-based regimen.…”

“…Three papers reported on retrospective analyses focusing on patients continuing trastuzumab beyond disease progression [9][10][11]. Those studies included patients who had received at least two subsequent trastuzumab-based regimens for metastatic disease.…”

“…These data, coupled with the tolerability of trastuzumab, have suggested to clinicians that continuing trastuzumab and changing the companion cytostatic agent could be a reasonable option in patients progressing on trastuzumab-based therapy. A few retrospective analyses in patients with HER2-positive advanced breast cancer showed encouraging response rates and survival when, upon disease progression, trastuzumab was continued and patients received further chemotherapy [9][10][11]. One obvious flaw of these reports is that patients discontinuing trastuzumab because of serious trastuzumab-related toxicity, or those experiencing rapid disease progression during the initial trastuzumab-based therapy and unable to receive further anticancer therapy, were not considered.…”

Continued Use of Trastuzumab Beyond Disease Progression in the National Comprehensive Cancer Network: Should We Practice Ahead of the Evidence?

“…There were only data from uncontrolled studies [2,3] and case series [4 -7] suggesting that the practice was safe and not associated with excess toxicity. In addition, responses and longer survival were seen with subsequent lines of trastuzumabbased therapy; however, given the lack of randomization, several articles called for randomized trials to clarify the true benefit [8,9]. Given the paucity of information to support this practice, starting in 2005, guidelines from the National Comprehensive Cancer Network (NCCN) stated "the value of continued trastuzumab following progression on first linetrastuzumab containing chemotherapy for metastatic breast cancer is unknown.…”