Clinical benefit of COX-2 inhibitors in the adjuvant chemotherapy of advanced non-small cell lung cancer: A systematic review and metaanalysis

BACKGROUND Lung cancer is a major cause of death among patients,and non-small cell lung cancer(NSCLC)accounts for more than 80%of all lung cancers in many countries.AIM To evaluate the clinical benefit(CB)of COX-2 inhibitors in patients with advanced NSCLC using systematic review.METHODS We searched the six electronic databases up until December 9,2019 for studies that examined the efficacy and safety of the addition of COX-2 inhibitors to chemotherapy for NSCLC.Overall survival(OS),progression free survival(PFS),1-year survival rate(SR),overall response rate(ORR),CB,complete response(CR),partial response(PR),stable disease(SD),and toxicities were measured with more than one outcome as their endpoints.Fixed and random effects models were used to calculate risk estimates in a meta-analysis.Potential publication bias was calculated using Egger’s linear regression test.Data analysis was performed using R software.RESULTS The COX-2 inhibitors combined with chemotherapy were not found to be more effective than chemotherapy alone in OS,progression free survival,1-year SR,CB,CR,and SD.However,there was a difference in overall response rate for patients with advanced NSCLC.In a subgroup analysis,significantly increased ORR results were found for celecoxib,rofecoxib,first-line treatment,and PR.For adverse events,the increase in COX-2 inhibitor was positively correlated with the increase in grade 3 and 4 toxicity of leukopenia,thrombocytopenia,and cardiovascular events.CONCLUSION COX-2 inhibitor combined with chemotherapy increased the total effective rate of advanced NSCLC with the possible increased risk of blood toxicity and cardiovascular events and had no effect on survival index.

Theoretical Studies on the Kinetics and Mechanisms of Reactions for Methyl Vinyl Ether and Ozone

The interconversion between the two distinct isomers of methyl vinyl ether （MVE）, the formation of the primary ozonides from O3-initated reactions of MVE, the transformation between the primary ozonides, and the subsequent fragmentation were studied using quantum chemical methods at the BHandHLYP/6311＋＋G（d,p） level of theory for optimized geometries and frequency calculations and at the QCISD/631G（d,p） level for the single point energy calculations. The rate coefficients were calculated for the temperature range 280-440 K by using the canonical transition state theory （TST）. For ozone addition to MVE, there are two different possibilities discussed on the basis of two different possible orientations for ozone attack. The results of the theoretical study indicate that although the synperiplanar-MVE is 7.11 kJ/mol more stable than the antiperiplanar-MVE, the antiperiplanar-MVE plays a more important role in formation of the primary ozonides because the primary ozonides formed from the ozone addition antiperiplanar-MVE are more stable and the energy barriers corresponding to transition states are lower. The intereonversion between the primary ozonides formed from the ozone addition to antiperiplanar-MVE is the most accessible compared with the transformations between other primary ozonides. The cleavage of the primary ozonides mainly leads to the formation of the CH2OO, which is in agreement with the experimental estimates. The calculated overall rate constant for the ozone-initiated reactions is 4.8× 10^-17 cm^3/（molecule.s） at 298.15 K, which agrees with the experimental value for ethyl vinyl ether.