PD-1 inhibitors Highly Effective for Colorectal Cancer in Lynch Syndrome Patients

PD-1 inhibitors were given as a monotherapy or combined with other therapies like anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) treatment, radiotherapy, chemotherapy, and targeted therapy.

The key results of the study are:

• There were a total of 75 patients with a history of LS. The median age of these patients was 39 years.
• The patients were followed up for 27 months.
• The objective response rate (ORR) was 70.7%.
• The percentage of complete and partial responses was 28.0% and 42.7%.
• Four of five cases had proficient MMR (pMMR) or microsatellite stable (MSS) that were not responsive.
• Mucinous/signet-ring cell differentiation was associated with a lower ORR.
• The 3-year overall survival and progression-free survival were 91.2% and 82.2%, respectively.
• During surveillance, 26 patients had Polyps.
• Seven adenomas which were larger than 7mm disappeared after treatment.

In this study, researchers highlighted the effectiveness of PD-1 inhibitors for LS dMMR/MSI-H CRC. They believe MSI and MMR status is crucial to tumour response to PD-1 inhibitors. They also mentioned less sensitivity of Mucinous and signet-ring cell LS CRC to PD-1 inhibitors.

Large adenomas of size ≥7mm in LS patients may respond to PD-1 inhibitors.

For  further reference log on to:

https://www.ejcancer.com/article/S0959-8049(23)00355-6/fulltext