Statistical evaluation of factors influencing prognosis of gastric cancer patients: Predication of prognosis on patient clusters.

We found ten clusters of gastric cancer patients in Imanaga's group under a cancer research project organized by the Ministry of Health and Welfare, and evaluated the prediction of prognosis of those patients in each cluster by using the censored regression of postsurgical survival time on a "prognosic" factor which has been extracted from nine explanatory variables observed mainly at the time of surgery. Consequently, the ten clusters were interpreted and confirmed to be useful for prediction of the patient prognosis by comparison of the failure rates among those clusters and between treated (administration of chemotherapy) group and control group.