Correlation of multiple proteins with clinic-pathological features and its prognostic significance in colorectal cancer with signet-ring cell component.

OBJECTIVE: Primary colorectal cancer (CRC) with signet-ring cell (SRC) component is a distinct tumor of colon and rectum, and its prognosis is very poor. Reliable markers to predict the poor clinical outcome of this subgroup cancer remains undetermined. Therefore, we perform this study to investigate the prognosis value of seven proteins in CRC with SRC component . PATIENTS AND METHODS: This study involved 117 patients diagnosed with CRC with SRC component between January 2008 and August 2015 at Fudan University Shanghai Cancer Center. The samples from these patients were analyzed by immunohistochemistry to reveal the expression levels of p53, p21, E-cadherin, COX-2 (Cyclo-oxygenase-2), Bcl-2, CD44 and Ki-67. Kaplan-Meier analysis and log-rank testing were performed to estimate survival. Subsequently, a Cox proportional hazard model was used to calculate hazard ratios for the risk of death.
RESULTS: The p21, p53, COX-2, E-cadherin, Bcl-2, CD44 and Ki-67 expression were detected in 60.5%, 61.3%, 69.7%, 68%, 28.6%, 62.2% and 75.6% of the samples, respectively. The positive expression of p53 (p=0.017) and the negative expression of COX-2 (p=0.001) or E-cadherin (p=0.047) in CRC with SRC component were significantly associated with decreased overall survival, but the other expression levels were not. In a multivariate analysis, the negative expression of COX-2 was found to be an independent prognostic factor for poorer overall survival (hazard ratio, 0.37; 95% confidence interval, 0.19 to 0.75, p=0.003)
CONCLUSIONS: The COX-2 positive expression in CRC patients with SRC component had a poorer outcome than patients who were COX-2-negative. Therefore, COX-2 could be considered as an indicator for appropriate treatment and intensive follow-up in these subgroup patients.