Tthere is an ongoing debate about how long Herceptin should be continued for metastatic disease. It is not clear if continuing trastuzumab after progression improves the OS of women with metastatic breast cancer. Accordingly, the final overall analysis of the GBG-26/BIG 3-05 Phase III study did not demonstrate a significant survival benefit for treatment beyond progression with trastuzumab. In the same study, a non-planned, post hoc analysis suggested that patients receiving anti-Her2 treatment as third-line therapy may benefit from trastuzumab, as they had better postprogression survival than those not receiving the treatment (18.8 months versus 13.3 months; HR:0.63; P=0.02).3
Trastuzumab is an effective targeted agent. However, it is estimated that, for each life saved, 1025 patients develop heart disease. For example, the N9831 (Arm C) and NSABP B31 joint analysis revealed that, on average, for every three lives saved by reducing breast cancer, two patients died of heart disease or other complications. .R. Haq et al says: “Discontinuation of maintenance trastuzumab in this patient population after a limited time should be explored cautiously while a global collaborative effort for a randomized trial is awaited.”.
Therefore, continuing this drug indefinitely cannot be considered to be medically necessary.
Florin Badulescu et al, More than 9 years of continuous trastuzumab treatment in metastatic breast cancer without cardiac toxicity: a case report and literature review. Onco Targets Ther. 2014; 7: 19111917.
Ihnenfeld Arciénega et al, Prolonged complete remission of metastatic HER2-positive breast cancer after continuous trastuzumab treatment: a case report and review of the literature. Target Oncol. 2015 Jun;10(2):297-301
R. Haq etal, ,Duration of trastuzumab in patients with HER2-positive metastatic breast cancer in prolonged remission. Curr Oncol. 2016 Apr; 23(2): 91–95.