Concomitant depletion of PTEN and p27 and overexpression of cyclin D1 may predict a worse prognosis for patients with post-operative stage II and III colorectal cancer

Prognostic markers for colorectal cancer (CRC) have not yet been fully investigated. Phosphatase and tensin homolog (PTEN), p27 and Cyclin D1 play significant roles in tumorigenesis and cell cycle regulation, and therefore require evaluation for their prognostic value in this disease. The aim of the present study was to assess the prognostic value of the single and combined expression of PTEN, p27 and Cyclin D1 in CRC patients. Protein expression levels of PTEN, p27 and Cyclin D1 were examined by immunohistochemistry from 61 patients with CRC in either stage II or III. In the CRC tissues, the frequencies of PTEN(-), p27(-) and Cyclin D1(+) expression were 42.62% (26/61), 32.79% (20/61) and 45.90% (28/61), respectively. Depletion of PTEN and p27 was more common with respect to stage III, low grade and lymph node metastasis compared with stage II, moderate grade and no lymph node metastasis (P<0.05). Cyclin D1-positive expression was frequently detected in CRC of stage III, with lymph node metastasis and deeper invasion (P<0.05). The depletion of PTEN was significantly correlated with the loss of p27 (P<0.001) and with the increased expression of Cyclin D1 (P<0.001). PTEN(-) and/or p27(-) expression was significantly correlated with Cyclin D1(+) expression (P<0.05). Combined PTEN(-)/p27(-)/Cyclin D1(+) expression was correlated with a significant decrease in overall survival time (P<0.05). Combined p27(-) and Cyclin D1(+) expression indicated a worse overall survival time than other combined expression patterns. These findings indicate that the single expression of PTEN(-), p27(-) and Cyclin D1(+) and the combined detection of p27(-) and Cyclin D1(+) may be used as prognostic markers for overall survival time in CRC.