The role of sequential chemoradiotherapy in non-small cell lung cancer (NSCLC) patients who are not eligible for concurrent therapy has not been clearly defined. The aim of this study was to determine the usefulness of Karnofsky performance status (KPS) monitoring and to define the factors determining clinical deterioration during sequential chemoradiotherapy in patients treated from July 2009 to October 2014. The study included 196 patients. The clinical stage was defined as III A in 94 patients (48%) and III B in 102 patients (52%). Reduced KPS was found in 129 patients (65.8%). Baseline KPS had no significant prognostic significance. Deterioration of KPS during chemoradiotherapy was observed in 53 patients (27%) and had a negative predictive value for both worse-progression free survival (HR = 1.44; 95% CI: 1.03-1.99; p = 0.03) and overall survival (HR = 1.42; 95% CI: 1.02-1, 99; p = 0.04). The deterioration of KPS correlated with the disease control rate 6 weeks after the end of chemoradiotherapy (p = 0.0085). The risk of KPS worsening increased with each subsequent day between the end of chemotherapy and the start of radiotherapy (OR = 1.03; 95%CI: 1.01-1.05; p = 0.001), but decreased with each year of older age of patients (OR = 0.94, 95% CI: 0.9-0.98, p = 0.009). The time between the end of chemotherapy and the start of radiotherapy determined the prognosis of NSCLC after chemoradiotherapy. It should be adjusted to the age of patients.
Keywords: chemoradiotherapy; non-small cell lung cancer; performance status; prognosis.