PROSPECTIVE STUDY ON DEVELOPMENT OF EARLY GASTRIC CANCER

Abstract

It will provide an important information for a research on gastric cancer to know how long and it will take for an early gastric cancer to progress to an advanced cancer and what type of advanced cancer it will be if left untreated. However, it is not allowed to follow and observe such a progress from the practical aspect, because such an early gastric cancer must be surgically operated on as soon as possible once the diagnosis has been established. Therefore, investigations on a developmental process of early gastric cancer have been conducted based only on a retrospective study. But this method does not help to find out whether a lesion was carcinoma from the beginning because biopsy was not performed in the past. The results of this retrospective study will therefore, never go beyond the scope of speculation. The following results were obtained by a prospective study on the development of early cancer to advanced cancer by observing those cancer patients for over 6 months who refused or postponed operation due to complications after they were diagnosed to have an early gastric cancer by X-ray and endoscopic examination. 1. We were able to follow up 22 cases of early gastric cancer over 6 months, of which 8 cases remained in the early stage, 13 cases progressed to advanced cancers, and 1 case was unknown. 2. The time required of the early gastric cancer to develop advanced cancer was calculated on 21 cases with a known clinical course according to the method of Kaplan and Meier. In this method, a curve of survival rate was plotted by designating those remained at the early stage as survived and those developed into advanced cancer as dead, and the median value (50% midpoint) obtained was 36 months. Therefore, it is assumed that it requires 36 months for early cancer to become advanced one. 3. The following courses of macroscopic changes were confirmed in the path of shift from early gastric cancer to advanced cancer: (i) II cul (-)→Borr. I(1 case), (ii) II cul (+)→-Borr. III (4cases), (iii) II c + III→-Borr.III(5case), (iv) III + c→Borr. III (1 case), (v) IIa→Borr. II (1 case), (vi) I, II cul (-)→Borr. I (1 case)