Elevated CRP levels indicate poor progression-free and overall survival on cancer patients treated with PD-1 inhibitors.

Systemic inflammation suggested by elevated CRP is a very strong indicator for adverse prognosis on patients treated with anti-PD-(L)1 agents and has a potential negative predictive value for treatment with anti-PD-(L)1 agents. Prospective trials should investigate whether patients with elevated CRP gain any significant benefit from anti-PD-1 therapy.