Prolonged complete remission of metastatic HER2-positive breast cancer after continuous trastuzumab treatment: a case report and review of the literature

Abstract

Metastatic breast cancer is considered an incurable disease. Targeted treatments against the human epidermal growth factor receptor 2 (HER2), however, significantly improve survival in patients with metastatic HER2-positive breast cancer. Some patients may respond with prolonged complete remission. Evidence on safety of long-term trastuzumab and risk of relapse after trastuzumab cessation is limited. We present a case of an 81-year-old patient with HER2-amplified metastatic breast cancer (MBC) in the liver. Following taxane-based chemotherapy in combination with trastuzumab after local treatment resulted in a complete radiological remission after 21 months of trastuzumab maintenance therapy. The patient remains in complete remission 6 years later and continues to receive trastuzumab as maintenance therapy. Prolonged remission in cases with complete response under trastuzumab-based regimens for metastatic HER2-positive breast cancer can be observed in some patients. Reviewing the few available cases published in the literature, these patients share some common characteristics: hormone receptor negative disease and metastases to the liver. There is no evidence that trastuzumab maintenance treatment can be safely interrupted after a certain time period. AbstractIntroduction: Metastatic breast cancer is considered an incurable disease. Targeted treatments against the human epidermal growth factor receptor 2 (HER2), however, significantly improve survival in patients with metastatic HER2-positive breast cancer. Some patients may respond with prolonged complete remission. Evidence on safety of long-term trastuzumab and risk of relapse after trastuzumab cessation are limited. Case presentation: We present a case of an 81-year-old patient with HER2-amplified metastatic breast cancer (MBC) in the liver. Following taxane-based chemotherapy in combination with trastuzumab after local treatment resulted in a complete radiological remission after 21 months of trastuzumab maintenance therapy. The patient remains in complete remission 6 years later and continues to receive trastuzumab as maintenance therapy. Conclusion: Prolonged remission in cases with complete response under trastuzumab based regimens for metastatic HER2-positive breast cancer can be observed in some patients. Reviewing the few available cases published in the literature, these patients share some common characteristics: hormone receptor negative disease and metastases to the liver. There is no evidence that trastuzumab maintenance treatment can be safely interrupted after a certain time period.

Research priorities in metastatic breast cancer: A James Lind Alliance Priority Setting Partnership

“…The effect of such breaks on the disease progression, however, is largely unknown. Retrospective data mainly from case reports suggest there may be some patients for whom treatment may be safely interrupted . Further research is required to understand for which patients this is a safe option.…”

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

“…In the literature, there are only a few published case reports of long survival rates in Trastuzumab-treated patients (7,(9)(10)(11)(12)(13). This may be due to the fact that the majority of patients experience progression of disease within two years and the percentage of durable remissions remains unknown (6).…”

Current therapeutic landscape for advanced gastroesophageal cancers

“…The maintenance of anti-HER2 is often used in breast cancer patients without the lack of strong evidence (41,42). Data in AGC are scarce (43), but a randomized phase II trial is currently evaluating the issue of maintenance in non-progressive patients (NCT02678182) ( Table 2).…”