Nuclear β-catenin accumulation as a prognostic factor in Dukes' D human colorectal cancers

β-catenin is well recognized to play a crucial role as a transcriptional factor during the early step of colorectal carcinogenesis. Some reports concerning the clinical implications of cytoplasmic and/or nuclear β-catenin accumulation are available, though their results vary. On the other hand, the clinical implication of nuclear accumulation of β-catenin in Dukes' D colorectal cancers (with distant metastasis) has not been investigated. To assess its value as a prognostic marker in this stage, we selected the cases with synchronous liver metastasis. Thirty-eight surgically resected primary and corresponding metastatic liver tumors were examined immunohistochemically and the relationships between nuclear β-catenin accumulation and clinicopathological variables were analyzed. Of the 38 primary colorectal cancers analyzed, 11 (29%) showed nuclear accumulation of β-catenin with cytoplasmic staining. Nuclear accumulation positivity was more frequently associated with lymph node metastasis than being negative [100% (11/11) vs. 67% (18/27), p=0.04]. There was a significant difference in median survival time between the nuclear β-catenin positive group (1130 days) and the negative group (2102 days: p=0.037). Interestingly, all of the patients (9/9) in the former group had died when the recurrence was in the liver, while 42% (8/19) in the latter group had survived even if the recurrence was in the liver (p=0.03). In conclusion, though these results were obtained in a small series of patients, nuclear accumulation of β-catenin may be a useful prognostic marker even in Dukes' D colorectal cancers.