Neoadjuvant T-DM1 for HER2-positive breast cancer used as a bridging strategy during COVID-19 pandemic: lessons learned-a case series.

Background: Coronavirus disease 19 (COVID-19) has played a pivotal role in changing medical care around the world. During the pandemic, the operating rooms (ORs) were closed to elective surgery. Since breast cancer surgery is not regarded as an emergent procedure, there was an adoption of treatment regimen modification due to delays in treatment. Therefore, a decision was made to bridge early-stage HER2-positive breast cancer patients with neoadjuvant treatment to postpone surgery. Consequently, to reduce the frequency of dosing and the number of visits, as well as avoid steroid premedication, these patients were treated with ado-trastuzumab emtansine (T-DM1) every three weeks as opposed to weekly taxol and herceptin (TH). Case Description: Five patients with early-stage HER2-positive cancer were treated with neoadjuvant T-DM1 3.6 mg/kg IV every three weeks. Three of the five patients developed cancer progression identified by their physical exam and/or imaging. T-DM1 was discontinued, and all three patients underwent immediate surgery. The remaining two patients, 4 and 5, had a complete and partial pathological response, respectively. All five patients received adjuvant therapy after surgery, and currently, none of these patients show evidence of disease on follow-up. Conclusions: Our findings underscore the obstacles and treatment challenges encountered during the COVID-19 pandemic while preventing the spread of the virus and cancer progression. Furthermore, the use of T-DM1 for neoadjuvant treatment remains controversial, particularly when T-DM1 is used as a bridge to surgery during critical times. Perhaps better patient selection or a different drug regimen could have resulted in a better outcome in our study.