Would you consider adding HER2 targeted treatment to chemotherapy for a patient with locally advanced, HER2+ rectal cancer who is going to have total neoadjuvant treatment?

There are approximately 3-5% metastatic colorectal cancer patients who have HER2 amplification detected by either IHC, FISH, or by NGS that includes an RNA test (Loree et al., PMID 29718453).

Clinical trials showed convincing evidence that HER2 targeted treatment is effective for HER2 positive metast...

I think we need to focus on 2 things while we are treating rectal cancer patients - 1. Let's try not to give them a colostomy bag. Let's try to watch and wait. We are successfully using the watch and wait approach at our institution (Medical College of Wisconsin, Milwaukee). 2. Most patients with lo...