摘要
BACKGROUND：Progression-free survival（PFS）has not been extensively investigated as a surrogate for survival in the firstline treatments of pancreatic cancer.The aim of this review was to evaluate PFS as a potential surrogate endpoint for overall survival（OS）in advanced pancreatic cancer in trials comparing poly-chemotherapy to gemcitabine alone.DATA SOURCES： A systematic literature search in PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials was conducted. The key words included randomized trial, first-line chemotherapy, pancreatic cancer, gemcitabine and poly-chemotherapy. Adjusted weighted linear regression was used to calculate Rs （Spearman＇s rank-order correlation coefficient） between PFS and post-progression survival （PPS） with OS （Rs） and between treatment effects on PFS and OS （RHR）. RESUEFS： A total of 30 trials including 8467 patients met the inclusion criteria. Correlation between the treatment effects on PFS and OS （RHR=0.78） and between the endpoint PFS and OS was high across all studies （Rs=0.75）. The slope of the re- gression line was 0.76±0.26, indicating that an agent produc- ing a 10% risk reduction for PFS will provide a 7.6%±2.6% risk reduction for OS. Correlation between PPS and OS was very strong （Rs=0.71） and accounted for more than 50% of the whole OS variability （R2=0.57）. CONCLUSION： Because of the robust correlation with OS and the potential influence of PPS caused by the second line therapies, it may be justified to consider PFS as a surrogate endpoint in trials evaluating new cytotoxic agents when gemcitabine is the control arm.
BACKGROUND：Progression-free survival（PFS）has not been extensively investigated as a surrogate for survival in the firstline treatments of pancreatic cancer.The aim of this review was to evaluate PFS as a potential surrogate endpoint for overall survival（OS）in advanced pancreatic cancer in trials comparing poly-chemotherapy to gemcitabine alone.DATA SOURCES： A systematic literature search in PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials was conducted. The key words included randomized trial, first-line chemotherapy, pancreatic cancer, gemcitabine and poly-chemotherapy. Adjusted weighted linear regression was used to calculate Rs （Spearman＇s rank-order correlation coefficient） between PFS and post-progression survival （PPS） with OS （Rs） and between treatment effects on PFS and OS （RHR）. RESUEFS： A total of 30 trials including 8467 patients met the inclusion criteria. Correlation between the treatment effects on PFS and OS （RHR=0.78） and between the endpoint PFS and OS was high across all studies （Rs=0.75）. The slope of the re- gression line was 0.76±0.26, indicating that an agent produc- ing a 10% risk reduction for PFS will provide a 7.6%±2.6% risk reduction for OS. Correlation between PPS and OS was very strong （Rs=0.71） and accounted for more than 50% of the whole OS variability （R2=0.57）. CONCLUSION： Because of the robust correlation with OS and the potential influence of PPS caused by the second line therapies, it may be justified to consider PFS as a surrogate endpoint in trials evaluating new cytotoxic agents when gemcitabine is the control arm.
