Pemetrexed monotherapy versus pemetrexed plus platinum combination as second-line treatment for advanced non-small cell lung cancer

Background Pemetrexed is a novel folic acid antagonist with multiple targets,which has been widely used in thetreatment of non-small cell lung cancer （NSCLC）.The objective of this study was to compare the effects and toxicities inNSCLC patients treated with pemetrexed monotherapy versus pemetrexed plus a platinum combination agent,so as toprovide a basis for standard second-line chemotherapy.Methods The clinical data of 52 patients with NSCLC who were admitted to Shanghai Chest Hospital from August 2006to October 2008 were retrospectively analyzed.Ten of the 52 patients received pemetrexed monotherapy,and the other42 patients received the pemetrexed plus platinum regimen.The primary end point was overall survival （OS）.Theprogression-free survival time （PFS） was analyzed and the effects and toxicities were assessed.Survival analysis wasevaluated by Kaplan-Meier method.Single factor analysis and the COX regression model were done to analyze therelationship between the influential factors and the prognosis of disease.The elderly patients （≥60 years old） wereanalyzed separately as a subgroup.Results No statistically significant increase in OS （X=0.09,P=0.76）,PFS （X=0.15,P=0.70）,disease control rate （DCR）(X=0.06,P=0.81) or 1-year survival rate （X=0.33,P=0.57） was found between the two regimens.Single factor analysisshowed that the factors including surgery history,PS score before treatment,clinical stage,and response to second-linetreatment influenced the prognosis of NSCLC （all P<0.05）.COX regression analysis demonstrated that surgery history（P=0.041） and performance status （PS） score before treatment （P=0.043） may be associated with survival.The toxicity ofthe two regimens was similar.In the subgroup of elderly patients,no significant difference in OS （X=0.01,P=0.94）,PFS（X=0.14,m=0.70）,DCR （X=0.004,P=0.95）,or 1-year survival rate （X=0.03,P=0.87） was found between the tworegimens.The toxicity of combination therapy was significantly higher in terms of hematologic （X=9.95,P=0.01） andgastrointestinal adverse events （X=7.66,P=0.03）.Conclusions There is no significant difference in survival or side effects between these two regimens.For elderlypatients （≥60）,pemetrexed monotherapy shows similar efficacy and a better safety profile when compared withpemetrexed combination therapy.