In order to get information about the biological behavior of scirrhous gastric cancers in their growth, we examined 1) retrospective and 2) prospective follow-up cases of scirrhous cancer, 3) scirrhous cancers on the gastric remnant, 4) those misdiagnosed as early cancer and 5) similarity in sex ratio, location and histological type (backgrounds of growth) between early and advanced cancers by multivariate analysis. The results obtained were as follows: 1) In the five well documented cases of scirrhous cancer being available for retrospective study (see Table 1), superficial depressed lesions were seen previously. And four of the five were non-ulcerative (without converging folds) and the rest one was ulcerative. In these five cases intervals between elastic and contracted appearance (E-C interval) in their growth was very short. The shortest was only 40 days (see Fig. 1). 2) In contrast, in a case who had been followed up from localized advanced to scirrhous cancer prospectively, the term was relatively long, namely one year and half. 3) In eight cases who had recurred as scirrhous cancer on the gastric remnant and been resected, time intervals between the initial operation and recurrence detected were diverse, and there was no relationship between the time intervals and clinicopathological features of the primary lesion (Table 2). 4) Six cases of scirrhous cancer were misdiagnosed as early by radiology and/or endoscopy (Table 3). In these six, gastric wall was not contracted macroscopically in spite of the presence of diffuse scirrhous invasion histologically ("elastic scirrhous cancer"). 5) According to the multivariate analysis (Hayashi's quantification theory No. 3) examining the similarity in backgrounds of growth between 937 cases of early and 2065 of advanced cancers, non-ulcerative II c type of early cancers, particularly in younger generation showed close similarity to scirrhous cancers. The above results may suggest following consideration about development of scirrhous cancers: Most of the original lesions correspond to II c type of early cancers without converging folds (non-ulcerative) in younger generation (results 1 and 5). Growth patterns from the original to the final gross appearance are classified into two groups, slow (through locally advanced stage as result 2) and rapid (direct change from early lesion as result 1). Because E-C interval is very short in the rapid growing cases (result 1) and scirrhous cancer is not always contracted macroscopically (result 4), it is possible to consider the presence of some endogenous factors from cancer cells, which make "elastic scirrhous cancers" contracted rapidly and simultaneously.(ABSTRACT TRUNCATED AT 400 WORDS)