Prognostic value of p27, p53, and vascular endothelial growth factor in Dukes A and B colon cancer patients undergoing potentially curative surgery.

PURPOSE: Early-stage colon cancer patients (Dukes A or B; pT1-T3 pNO pMO) are excluded from adjuvant chemotherapy following potentially curative surgery because they are expected to have good long-term survival. However, 20 percent to 30 percent of these patients ultimately succumb from recurrent disease. This indicates that the conventional staging procedures may be unable to precisely predict cancer prognosis. METHODS: In 65 early-stage colon cancers, we investigated by immunohistochemistry the role of molecular markers such as p27, p53, and vascular endothelial growth factor in identifying high-risk patients who may benefit from adjuvant treatments. RESULTS: No clinicopathologic factor, namely Dukes stage, t parameter, number of resected nodes, and vascular or lymphatic invasion, was found be an independent significant predictor of disease-specific and disease-free survival. In contrast, each molecular marker predicted survival and recurrence rates much better than the conventional Dukes staging system. The best combination of variables for prediction of long-term outcome and recurrence rate included p27, p53, and vascular endothelial growth factor. Interestingly, the greater the number of molecular alterations, the lower the five-year estimated survival function. Nearly all cancer-related deaths were observed among patients whose colon cancers expressed all three molecular alterations. Regardless of Dukes stage, the recurrence rate was found to increase with the increase in the number of molecular alterations. Early-stage colon cancers expressing p27 down-regulation and high p53 and vascular endothelial growth factor immunoreactivity showed a 100 percent actuarial four-year recurrence rate. CONCLUSIONS: Assessment of molecular alterations may be useful to identify a higher-risk group of early-stage colon cancer patients who may benefit from adjuvant chemotherapy.

Determination of molecular marker expression can predict clinical outcome in colon carcinomas.

PURPOSE: Conventional staging procedures are often unable to precisely predict prognosis in colorectal cancer (CRC). In this study, we set out to investigate the possible role of molecular/structural indicators involved in cell cycle regulation (p27 and p53), apoptosis (p53 and p27), and tumor neoangiogenesis [p53, vascular endothelial growth factor (VEGF), and microvessel count] in predicting tumor behavior and clinical outcome in CRC patients EXPERIMENTAL DESIGN: Analysis of the above indicators was performed by immunohistochemistry on 104 CRC patient samples and 25 normal colon mucosa specimens. RESULTS: Intense p27 nuclear staining was found in normal colon mucosa, with p53 nuclear staining and VEGF cytoplasmic accumulation <10%, and low microvessel count. In contrast, in CRC samples, p27 was down-regulated in 53.8%, p53 protein was overexpressed in 52%, and VEGF stained positive in 67.3% of the cases, respectively. Multiple regression analysis showed that molecular markers were strongly correlated. In patients treated with curative surgery, a significant relationship was seen between p27 down-regulation and Dukes' stage, nodal status, and the presence of distant metastases. VEGF overexpression correlated significantly with Dukes' stage, tumor (t) and metastasis (m) parameters, and left site. Stepwise regression selected p27, p53, VEGF, and Dukes' stage as the best combination of variables capable of predicting both disease-specific and disease-free survival. CONCLUSIONS: The investigated indicators may be useful for the prediction of outcome and recurrence rate in curatively treated CRC patients. In conjunction with clinical and pathological staging, they may provide a stronger indication of clinical outcome than staging alone and help better select therapeutic options in CRC patients.