Researchers are investigating the use of immune checkpoint inhibitors for the treatment of advanced colorectal cancer. They find that this therapy is more effective in patients with DNA mismatch-repair deficiency compared to patients with an intact mismatch-repair mechanism. Which of the following most likely explains the improved efficacy of the drug in the first group of patients?

Question

Researchers are investigating the use of immune checkpoint inhibitors for the treatment of advanced colorectal cancer.  They find that this therapy is more effective in patients with DNA mismatch-repair deficiency compared to patients with an intact mismatch-repair mechanism.  Which of the following most likely explains the improved efficacy of the drug in the first group of patients?

Quizplus · Accepted Answer

Eductional Objective: Because tumors with defective DNA mismatch repair generate high levels of neoantigens, they are particularly dependent on adaptations (eg, overexpression of immune checkpoints) to avoid cytotoxic T-cell destruction.  Treatment with immune checkpoint inhibitors restore antitumor cytotoxic T-cell activity and often dramatically reduce tumor burden.

Researchers Are Investigating the Use of Immune Checkpoint Inhibitors for the Treatment