Dr Michael Foote speaks to ecancer about a phase II study that evaluates HER2-targeted therapy with trastuzumab and tucatinib in patients with locally advanced, HER2-positive rectal cancer.

The combination of HER2-targeted therapy and chemotherapy demonstrated high response rates, with a substantial proportion of patients achieving complete clinical response and avoiding surgery or radiation.

Dr Foote says that these findings highlight the potential for a non-operative, organ-preserving treatment approach in selected patients.

Responses were particularly notable in tumours with high HER2 expression, suggesting a predictive role for HER2 amplification in guiding treatment decisions.

The regimen was feasible, and all treated patients remained alive without metastatic recurrence at follow-up, supporting further investigation of this strategy in rectal cancer.