Cancer monitoring of Shanghai showed a rapid increase in the incidence of colorectal cancer. Colorectal cancer risk assessment allows for rapid screening of high-risk populations. The colorectal cancer screening of elderly residents is ongoing since 2013 in Shanghai. This initiative screened 85,525 people from 11 communities of the Qingpu District. Screening included a questionnaire-based risk assessment and two Fecal Occult Blood Tests (FOBTs). We conducted a retrospective case study of patients with positive screening results that underwent fibro-colonoscopy examinations to investigate their histories of schistosoma infection, smoking, alcohol consumption, and dietary habits. A total of 85,525 people were screened in this study. Colorectal cancer was resulted in a prevalence of 59.84/100,000. And the prevalence of schistosoma infection was 400/100,000. Among patients with schistosoma infection, the positive rate of FOBT was 67.01%, in contrast to an overall positive rate of FOBT among all subjects of 17.00% [(Pearson ⎥2=672.42, P < 0.0001, OR = 3.94 (3.67,4.23)]. The prevalence of colorectal cancer among patients with schistosoma japonicum infections was 4,155.84/100,000, while the prevalence of colorectal cancer among all subjects was 44.15/100,000 [Pearson2 = 980.62, P < 0.001, OR = 94.12 (53.05, 166.97)]. Our study found a high degree of correlation between late stage schistosoma infection of the intestinal tract and the occurrence of colorectal cancer and colonic adenoma. For patients with lesions caused by schistosoma infections of intestinal tract, the risk of colorectal cancer was higher than that of patients without intestinal schistosoma infections. Early screening and risk assessment can facilitate early diagnosis and treatment of colorectal cancer and colonic adenoma.

Tissue-derived RNA, DNA and protein samples become more and more crucial for molecular detection in clinical research, personalized and targeted cancer therapy. This study evaluated how to biobanking colorectal tissues through examining the influences of cold ischemic time and freeze-thaw cycles on RNA, DNA and protein integrity. Here, 144 pairs of tumor and normal colorectal tissues were used to investigate the impact of cold ischemic times (0-48h) on RNA, DNA and protein integrity at on ice or room temperature conditions. Additionally, 45 pairs of tissues experienced 0-9 freeze-thaw cycles, and then the RNA, DNA and protein quality were analyzed. On ice, RNA, DNA and protein from colorectal tumor and normal tissues were all stable up to 48h after surgery. At room temperature, RNA in colorectal tumor and normal tissues began to degrade at 8h and 24h, respectively. Meanwhile, the tumor tissues DNA degradation occurred at 24h after surgery at room temperature. Similarly, the protein expression level of tumor and normal tissues began to change at 24h after the surgery at room temperature. Interestingly, tissue RNA and DNA remained stable even after 9 freeze-thaw cycles, whereas the proteins levels were remarkably changed after 7 freeze-thaw cycles. This study provided a useful evidence on how to store human colorectal tissues for biobanking. Preserving the surgical colorectal tissue on ice was an effective way to prevent RNA, DNA and protein degradation. Importantly, more than 7 repeated freeze-thaw cycles were not recommended for colorectal tissues.