Association between poor performance status and risk for toxicity during erlotinib monotherapy in Japanese patients with non-small cell lung cancer: Okayama Lung Cancer Study Group experience

Background: The relationship between poor performance status (PS) and toxicity during chemotherapy is controversial. We examined this for erlotinib monotherapy in non-small cell lung cancer (NSCLC) patients. Patients and methods: Toxicity during the first month of therapy was recorded in 209 patients receiving erlotinib for NSCLC, and its association with PS was assessed. Results: Of 209 patients, 52, 115, 30 and 12 had a PS of 0, 1, 2 and 3-4, respectively. Treatment was discontinued in 26% of patients within 1 month, with a higher rate in poorer PS patients (17%, 25%, 37% and 42%). Discontinuation was predominantly due to disease progression, rather than adverse events, in both the whole cohort (82% vs. 18%) and the poorest PS subgroup (100% vs. 0%). Three, two, and four patients with a PS of 1, 2 and 3-4, respectively, died within 1 month; all six deaths of PS 2-4 patients were attributed to disease progression. Treatment interruption and dose reduction rates were similar among the subgroups. The principal adverse event was skin rash, with identical incidence in all PS subgroups. Conclusions: Poor PS is unlikely to increase the risk for toxicity during erlotinib monotherapy, but was related to low compliance, probably because of disease progression rather than treatment-related toxicity.