Phosphatase of regenerating liver-3 (PRL-3) has been associated with metastasis promotion. However, clinical applications of this association have not yet been clearly demonstrated. In this study, we evaluated the relation of PRL-3 mRNA level in primary colorectal cancer to the corresponding stage and to other clinicopathologic factors.

Two hundred forty-five patients with histologically-proven colorectal cancer underwent surgery between January 2004 and December 2006. RNA was extracted and cDNA was prepared by using reverse transcription. Quantification of PRL-3 was done using a real-time polymerase chain reaction.

Eighty-six cases with well-preserved specimens were enrolled: 53 males and 33 females. The mean age was 63.4 years. According to tumour node metastasis (TNM) stage of the American Joint Committee on Cancer (AJCC), stage I was 11 cases, stage II was 38 cases, stage III was 23 cases, and stage IV was 14 cases. Among stage IV cases, one case was combined with liver and lung metastases, and one case was combined with liver metastases and peritoneal dissemination. The remaining stage IV patients were combined with only liver metastases. There was a significant correlation in PRL-3 mRNA expression between primary colorectal cancer and corresponding tumor stage. PRL-3 mRNA expression was increased in the liver metastases cases. Lymphatic and vascular invasion were significantly related with PRL-3 mRNA levels.

Advanced stage prediction may be obtained by measuring the level of PRL-3 mRNA expression in primary colorectal cancer. Especially, the risk of liver metastases may be predicted by measuring the level of PRL-3 mRNA expression in primary colorectal cancer. Further study is required to confirm these preliminary results.