# Neoadjuvant immunotherapy leads to complete pathologic response in locally advanced colon cancer

## TL;DR

Neoadjuvant immunotherapy with pembrolizumab led to a complete pathologic response in a locally advanced colon cancer case, avoiding major surgery.

## Contribution

Demonstrates a complete pathologic response in locally advanced dMMR CRC using neoadjuvant pembrolizumab.

## Key findings

- A patient with locally advanced dMMR CRC achieved complete pathologic response after neoadjuvant pembrolizumab.
- A scoping review found promising tumor responses with neoadjuvant immunotherapy in dMMR CRC.
- The treatment potentially avoids the need for hepatectomy in eligible patients.

## Abstract

Immunotherapy is considered first line in patients with dMMR metastatic colorectal cancer (CRC). Recent studies have also shown promising results with neoadjuvant immunotherapy in locally advanced CRC. We report a case in which neoadjuvant immunotherapy with pembrolizumab resulted in complete pathologic response at time of resection as well as saved the patient the morbidity associated with a hepatectomy. We also completed a scoping review of the literature which suggests promising tumor responses with treatment in dMMR CRC. Further randomized control trials to determine the magnitude of response and optimal regimen are needed.