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(degree of differentiation and Stage)p0.710.079366also a significant difference in survival based on the degree of differentiation (p=0.031; Figure 2). However, when pStage, micrometastasis, and degree of differ-entiation were input as independent variables in a Cox proportional hazard model, all three factors were not significant (pStage III or higher, hazard ratio (HR): 2.8, CI: 0.7-12, p=0.16; micrometastasis, HR: 2.7, CI: 0.8-9, p=0.11; well-differentiated, HR: 1.5, CI: 0.4-5.5, p=0.5). Based on the p-values, pStage III or higher and micrometastasis showed a tendency to be related to survival, but degree of differentiation did not do so (Table 4).DiscussionThe first finding in this study is that micrometas-tasis to lymph nodes is not related to the degree of differentiation in esophageal SCC. There are contra-dictory findings for the relationship of micrometas-Table 3　 Logistic regression analysis of relationships between micrometastasis and pathological factors Figure 1　Survival curves for patients with and without micrometastasis. There was a significant difference in survival rate between those with and without micrometastasis (p=0.002).Degree of differentiationStageWell vs. moderateIII, IV vs. I, IIOdds ratio1.56.6tasis with the degree of differentiation in esophageal cancer. In our study, micrometastasis was associ-ated with the degree of differentiation in univariate analysis and well-differentiated cancers were likely to have micrometastasis. However, this was not shown in multivariate analysis. We speculate that the results in univariate analysis may be due to bias since patients with well-differentiated tumors tended to have higher stage disease in this cohort.Secondly, micrometastasis to lymph nodes was found to be a likely prognostic factor, even for locally advanced esophageal cancer. This might be a new finding because most previous studies have examined patients with early disease3-6), but this finding is also consistent with previous results for various carcinomas, including esophageal carci-noma. On the other hand, the degree of differentia-tion was not a prognostic factor in multivariate Confident intervals0.2 - 11.50.8 - 55