About 430,000 men and 274,000 women were diagnosed with cancer of the rectum globally in 2018, with cumulative lifetime risks of 1.2% and 0.65%, respectively. 1 Approximately 10% of rectal tumors diagnosed worldwide are reported to be mismatch repair-deficient. 2 Traditionally, rectal cancers are treated with neoadjuvant chemotherapy, radiotherapy, and surgery. However, in recent years, immunotherapy, particularly checkpoint inhibitor therapy with programmed death-1 (PD-1) inhibitors, have been utilized for cancer treatment.
It is especially effective in a subset of tumors characterized by mismatch repair deficiency and microsatellite instability. 3 A small-scale clinical trial in the US used dostarlimab, an anti–PD-1 monoclonal antibody, as a single agent to treat mismatch repair–deficient, locally advanced rectal cancer. The first 12 patients showed unparalleled success in achieving…
