Knowledge, Attitudes, Preventive Practices and Screening Intention about Colorectal Cancer and the Related Factors among Residents in Guangzhou, China

Background: In Guangzhou, China, colorectal cancer (CRC) is the second most commonly diagnosed cancer. The government initiated a CRC screening program in 2015, and investigating the knowledge, attitudes, and practices toward CRC would help facilitate the participation of the program. Methods: A cross-sectional survey was conducted from October 2014 to September 2015. Questionnaires were passed out with a cluster sample in 15 randomly selected primary schools of Guangzhou China, and one of each student's family members aged between 20 to 65 years old were included. Results: A total of 6839 questionnaires were obtained and the successful response rate was 78.5%. The majority (88.3%) of them were under 46 years old and female subjects accounted for 65.8%. Over 80% of the respondents knew that CRC was able to be cured by early diagnosis and treatment and that tobacco use, alcohol abuse, and dietary without enough fruits or vegetables may increase the risk of CRC, although a few knowledge scores were relatively low, such as physical exercise as a protective factor and bowel habits change as a symptom suggestive of CRC. In contrast, only 52.2% of the subjects were sure to participate in a future CRC screening provided by local government. We further found that the higher level of knowledge about CRC risk and positive cancer preventive attitude and practice were associated with higher education level, female gender, and positive family history. Conclusion: These results suggested that the priority may be laid on improving the conversion from knowledge to practice to implement screening program in Guangzhou, while efforts should also be made to improve public awareness about CRC.

Associations of Epstein-Barr Virus DNA in PBMCs and the Subtypes with Breast Cancer Risk.

Objective: Epstein-Barr virus (EBV) has been found to be implicated in the development of breast cancer. The purpose of the present study was to identify the associations of EBV DNA and the subtypes in peripheral blood mononuclear cells (PBMCs) with the risk of breast cancer. Material and Methods: A case-control study with 671 breast cancer cases and 859 age-matched controls was conducted in Guangzhou, China. Face-to-face interviews were performed and blood samples were collected immediately after admission to the hospital for patients or after the interview for controls. EBV DNA in PBMCs and the subtypes were detected using Polymerase Chain Reaction (PCR) and restricted fragment length polymorphisms (RFLP). IgA antibodies against EBV VCA-p18 and EBNA-1 were examined using commercial enzyme-linked immunosorbent assay kits. Unconditional logistic regression analysis was applied to evaluate the associations of the DNA positivity and subtypes of EBV with the risk of breast cancer. Results: Among the 1530 subjects, 164 cases (24.4 %) and 206 controls (24.0 %) were positive for EBV DNA in PBMCs and no significant difference occurred between cases and controls. The presence of EBV DNA was related to the positivity of EBV IgA antibodies. Of the DNA positive samples, 71 cases and 109 controls for F/f subtype and 58 cases and 112 controls for C/D subtype were successfully obtained. The D subtype was associated with an increased breast cancer risk compared with the C subtype [OR (95% CI): 2.86 (1.25~6.53)]. We did not find an association of the F/f polymorphism with breast cancer risk. Conclusions: The present study suggested that the presence of EBV DNA in PBMCs may not be an appropriate biomarker for breast cancer risk. The subtype D of EBV was likely to be related to breast tumorigenesis.