Prokineticin 2 expression as a novel prognostic biomarker for human colorectal cancer

Molecular tumor biomarkers hold considerable promise for accurately predicting colorectal cancer (CRC) recurrence and progression. Prokineticin 2 (PROK2) may be associated with angiogenesis and tumor formation in some malignant tumors. However, its prognostic value remains unknown. We focused on the association between PROK2 expression and clinical characteristics of CRC to assess value of PROK2 as a potential biomarker for stage I-III CRC patients prognosis. Between 1992 and 2006, 436 consecutive patients with stage I-III CRC treated with curative resection were included. PROK2 expression in primary tumors was investigated using immunohistochemistry. An animal model of liver metastasis was used to assess the role of PROK2. Positive PROK2 expression in primary tumors was found in 222 of 436 (50.9%) human CRC specimens and was significantly associated with lymphatic invasion, lymph node metastasis, clinical stage, and postoperative liver recurrence rate. Recurrence-free survival was significantly shorter in patients with positive PROK2 expression than in those with negative PROK2 expression. PROK2 expression was an independent unfavorable prognostic indicator for CRC [hazards ratio, 2.119; 95% confidence interval, 1.315-3.415; p = 0.002]. PROK2 overexpression promoted liver metastasis in vivo. We suggest that positive PROK2 expression is observed in CRC primary tissues; thus, PROK2 may be a useful predictor for liver recurrence and prognosis in CRC.