Lycopene Consumption and Risk of Colorectal Cancer: A Meta-Analysis of Observational Studies.

A number of epidemiological studies have explored the association between lycopene or lycopene-rich food intake and the risk of colorectal cancer, but the results of these studies have not been consistent. We conducted a systematic review and meta-analysis of studies published in the PubMed and EMBASE databases to quantitatively assess the association between lycopene consumption and the risk of colorectal cancer. A total of 15 studies were included in the meta-analysis, and the summary relative risk (RR) for highest versus lowest category indicated no significant association between lycopene consumption and the risk of colorectal cancer [RR = 0.94, 95% confidence interval (CI): 0.80-1.10]. However, a significant inverse association was observed between lycopene consumption and the site of cancer in the colon (RR = 0.88, 95% CI: 0.81-0.96). We also found that the incidence of colon cancer and lycopene intake did not exhibit dose-response relationships. The Grades of Recommendations Assessment, Development and Evaluation (GRADE) quality in our study was very low. In conclusion, this meta-analysis indicates that lycopene consumption is not associated with the risk of colorectal cancer. Further research will be needed in this area to provide conclusive evidence.

[Effect of the change of caspase-3 activity on the neoadjuvant chemotherapy-induced apoptosis of large-intestinal carcinoma cells].

OBJECTIVES: To study the change of caspase-3 activity on the neoadjuvant chemotherapy-induced apoptosis by hydroxycamptothecin (HCPT) with 5-fluorouracil (5-Fu)/leucovorin (CF) in large-intestinal carcinoma, and to explore its mechanism. METHODS: HCPT 100 mg/dt-5, 5-Fu 500 mg/dt-5 and CF 200 mg/dt-5 were administered intravenously to 20 pre-operation patients. Samples were obtained during the operation. The changes of apoptotic cells and caspase-3 activity in large-intestinal carcinoma were evaluated with the optical microscopy and the colorimeteric assay respectively and were compared with non-chemotherapy group and normal intestinal tissue group. RESULTS: 1. The obvious cell apoptotic change could be observed under the optical microscopy in the neo-adjuvant chemotherapy group; 2. The level of caspase-3 activity was significantly higher in the neo-adjuvant chemotherapy group than in the non-chemotherapy and normal intestinal tissue group(P < 0.05); 3. The change of caspase-3 activity was closely correlated with the tumor differentiation and Dukes stage after the induction of pre-operative chemotherapy. CONCLUSION: HCPT combined with 5-Fu/CF may induce the apoptosis of large-intestinal carcinoma cells and caspase-3 takes part in the apoptotic process. The change of caspase-3 activity was closely correlated with the degree of the tumor differentiation and Dukes stage.