Analysis on application of minimum P-value approach to the study of clinical prognostic factors.

[Objective] To explore the optimal cutoff value by minimum P-value approach,and to provide references to the analysis of clinical prognostic factors.[Methods] Taking the overall survival time and ERCC1 expressions of 76 gastric cancer patients receiving platinum-based chemotherapy for example,we tried to find the maximal chi square value and the cutoff value of ERCC1 after multiple log rank testing,and the minimum P-value approach was used to correct the corresponding P value.[Results] The value of maximal chi square was 32.441,and the cutoff value of ERCC1 was 0.4632.The corrected P value was significant,and it indicated that ERCC1 was correlated with the survival time of the gastric cancer patients receiving platinum-based chemotherapy.[Conclusion] ERCC1 mRNA expression level is predictive marker of survival time for gastric cancer patients receiving platinum-based chemotherapy.Minimum P-value approach is suitable for the study of prognostic factors.