Effect of baseline cancer pain on the efficacy of immunotherapy in lung cancer patients

BACKGROUND: Cancer pain is a common symptom in cancer patients. However, few reports have evaluated the effect of baseline cancer pain on the efficacy of immunotherapy in lung cancer patients. The aim of this retrospective study is to reveal the effect of baseline cancer pain on the prognosis of lung cancer patients receiving immunotherapy. METHODS: We retrospectively reviewed the medical records of lung cancer patients who received immunotherapy at Zhejiang Cancer Hospital and were included 280 patients with or without baseline cancer pain. Propensity score matching (PSM) was used to minimize potential selection bias. Progression-free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meier estimation and log-rank tests. Cox proportional hazard regression analysis was performed to identify factors associated with survival independence. RESULTS: The median PFS and OS of the patients with baseline cancer pain were significantly shorter than that of patients without baseline cancer pain (PFS: 3.1 vs. 6.5 months, P=0.001; OS: 16.5 vs. 31.2 months, P<0.001). PSM also included 27 patients with or without breakthrough pain. Patients with breakthrough pain had significantly shorter median PFS and OS than those without breakthrough pain (PFS: 1.9 vs. 4.2 months, P=0.001; OS: 9.9 vs. 18.7 months, P=0.012). Cox analysis results implicated breakthrough pain as an independent prognostic factor for immunotherapy. CONCLUSIONS: Baseline cancer pain is a negative prognostic factor for lung cancer patients receiving immunotherapy. Patients with baseline cancer pain may have a worse survival prognosis if they develop breakthrough pain.