Objective: The best treatments for metastatic lung cancer patients are palliative.We evaluated the effects of metronomic chemotherapy on survival outcomes in this population.
Patients and Methods: Thirty-four subjects with treatment refractory (n=26) and treatment naïve (n=7) metastatic lung cancer were included in an open-label single arm efficacy study of metronomic chemotherapy. Patients were given a chemotherapy regimen of Tab. Cyclophsophamide 50 mg once daily and Cap. Etoposide 50 mg once daily, 3 weeks on and one week off in 28 day cycle over a minimum period of 3 months or until the progression of their disease whichever was earlier. Patients were assessed for treatment response using RECIST Criteria (version 1.1) and duration of progression-free survival and overall survival. Data were analyzed using Kaplan Meir survival analysis.
Results: The mean age of the study population was 63.4±11.2 years. The mean duration of metronomic chemotherapy was 94.9±60.4 days. Overall 64.7% had progressive disease and 26.5% had stable disease. There was a significant improvement in overall survival in those with ECOG performance status of 1 compared to ECOG status of 2 (median survival=240 vs. 52 days, Log Rank Mantel Cox=11.32, p=0.001) and pathology grade 2 compared to grade 3 (median survival=200 vs. 37 days, Breslows Wilcoxon=5.76, p=0.02) and stable disease on RECIST compared to progressive disease following metronomic chemotherapy (median survival=360 vs. 50 days, Log Rank Mantel Cox=8.68, =0.003). There was also a significant improvement in progression-free survival in those with ECOG performance status of 1 compared to ECOG status of 2 (median survival=98 vs. 52 days, Log Rank Mantel Cox=6.62, p=0.001) and in grade 2 compared to grade 3 disease (mean survival=97 vs. 32 days, Log Rank Mantel Cox=4.73, p=0.03). Tumor load and multiple organ sites of disease did not seem to influence survival.
Conclusions: The results suggest stable response in about one third of study population, favorable progression-free and overall survival rates following metronomic chemotherapy. Performance status is an important predictor in this category of population. VEGF and TPS levels don’t correlate clinically.