The A427 anchorage-independence assay as a screening tool to identify potential chemopreventive agents

An in vitro model for screening potential chemopreventive agents using inhibition of anchorage-independent growth of a human lung tumor cell line, A427, is described. A427 cells were selected for the model development, as they are known to be tumorigenic in animals, can grow in soft agarose, and their growth can be inhibited by a well-known chemopreventive agent, 13-cis-retinoic acid. Cells are plated on agarose, allowed to develop colonies for 28 days, the stained colonies are enumerated, and the inhibition of spontaneous colony formation measured. A cytotoxicity test is used concurrently with anchorage independent assay for measuring the relative survival of cells to ensure that any observed inhibition of anchorage independent growth is due to the biological activity of the chemopreventive agents, as it uses human cells as substrates rendering the efficacy data feasible for direct extrapolation to humans.     

Role of pomegranate and citrus fruit juices in colon cancer prevention

Colorectal cancer is the second leading cause of cancer-related deaths in the United States.Recent studies prove that though chemotherapeutic agents are being used for the treatment of colon cancer,they become non-effective when the cancer progresses to an invasive stage.Since consumption of certain dietary agents has been linked with various cancers,fruit juices have been investigated for their consistently protective effect against colon cancer.The unique biochemical composition of fruit juices is responsible for their anticancer properties.In this review,the chemo-preventive effect of fruit juices such as pomegranate and citrus juices against colon cancer are discussed.For this purpose,the bioavailability,in vitro and in vivo effects of these fruit juices on colorectal cancer are highlighted.Moreover,there is a scarcity of studies involving human trials to estimate the preventive nature of these juices against colon cancer.This review will support the need for more preclinical tests with these crude juices and their constituents in different colorectal cancer cell lines and also some epidemiological studies in order to have a better understanding and promote pomegranate and citrus juices as crusaders against colon cancer.     

Underutilisation of breast cancer prevention medication in Australia

Increased implementation of proven prevention strategies is required to combat rising breast cancer incidence. We assessed use of risk reducing medication (RRMed) by Australian women at elevated breast cancer risk. Only 2.4% had ever used RRMed. Higher breast cancer risk was statistically significantly associated with use of RRMed (OR 1.82, 95%CI: 1.08–3.07, p = 0.02 for ≥30% lifetime risk compared with 16%–29% lifetime risk), but parity, education level and family history of breast cancer were not. Breast cancer prevention medications are underutilised. Efforts are needed to incorporate breast cancer risk assessment and risk management discussions into routine health assessments for women.     

Cancer in inflammatory bowel disease

Patients with long-standing inflammatory bowel disease （IBD） have an increased risk of developing colorectal cancer （CRC）. Many of the molecular alterations responsible for sporadic colorectal cancer, namely chromosomal instability, microsatellite instability, and hypermethylation, also play a role in colitis-associated colon carcinogenesis. Colon cancer risk in inflammatory bowel disease increases with longer duration of colitis, greater anatomic extent of colitis, the presence of primary sclerosing cholangitis, family history of CRC and degree of inflammation of the bowel. Chemoprevention includes aminosalicylates, ursodeox, ycholic acid, and possibly folic acid and statins. To reduce CRC mortality in IBD, colonoscopic surveillance with random biopsies remains the major way to detect early mucosal dysplasia. When dysplasia is confirmed, proctocolectomy is considered for these patients. Patients with small intestinal Crohn＇s disease are at increased risk of small bowel adenocarcinoma. Ulcerative colitis patients with total proctocolectomy and ileal pouch anal- anastomosis have a rather low risk of dysplasia in the ileal pouch, but the anal transition zone should be monitored periodically. Other extra intestinal cancers, such as hepatobiliary and hematopoietic cancer, have shown variable incidence rates. New endoscopic and molecular screening approaches may further refine our current surveillance guidelines and our understanding of the natural history of dysplasia.     

Vitamin supplements among women with adenomatous polyps and cancer of the colon

Chemoprevention of various epithelial cancers with vitamins or minerals has been the subject of multiple intervention trials to assess the impact of supplementation. These include several trials in patients with adenomatous polyps of the colon, a precursor lesion for colon cancer. The authors interviewed 255 women who underwent colonoscopy at Columbia Presbyterian Medical Center between 1983 and 1985 with a telephone-administered structured questionnaire. Eleven interviews were excluded for various reasons. Overall, 57.7 percent of the 244 interviewees used vitamin pills on a regular basis (at least once a week for a year); 6.6 percent of the interviewees used vitamin A, 20.7 percent used vitamin C, and 16.2 percent used vitamin E. There were no statistically significant differences in vitamin usage among women with adenomatous polyps of the colon (105 cases), women with colon cancer (56 cases), and women without colonic neoplasia (83 cases). Despite widespread use of supplementary vitamins, this study failed to demonstrate major benefits in preventing colon polyps or cancer. Read in part at the Tenth Meeting of the American Society for Preventive Oncology, Bethesda, Maryland, March 7, 1986. Supported by NCI Grant No.CA37196, an American Cancer Society Junior Faculty Fellowship (AIN), a grant from the Andrew Mellon Foundation, and an internship from the Health Research Training Program of the NYC Department of Health (CMJ).     

炎症性肠病患者结直肠癌化学预防研究进展

炎症性肠病（IBD）主要包括溃疡性结肠炎（UC）和克罗恩病（CD）两种疾病。近年我国IBD的发病率不断上升，如未及时治疗，长期炎症将最终导致结直肠癌的发生风险增高。在各种结直肠癌预防措施中，化学预防日益受到关注。本文主要对IBD合并结直肠癌的现状和发病机制作一综述，重点介绍几种用于化学预防的药物。     

Dicarbonyl Electrophiles Mediate Inflammation-Induced Gastrointestinal Carcinogenesis

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A Nationwide Study on the Incidence of Breast Cancer in Korean Women with Osteoporosis Receiving Raloxifene Treatment

PurposeRaloxifene is a selective estrogen receptor modulator (SERM), and raloxifene treatment for osteoporosis is reimbursable under the Korean National Health Insurance. Evidence suggests that SERMs use reduces the risk of breast cancer in Asian population. Herein, we retrospectively investigated the protective effect of raloxifene on breast cancer rates in Korean population.MethodsUsing the Health Insurance Review and Assessment Service database, we selected women with osteoporosis aged 50 years and above. Patients treated for at least 2 years with raloxifene were assigned to the user group, whereas the remaining patients were assigned to the non-user group. The effect on breast cancer risk was assessed using the Cox proportional-hazards model with a time-dependent covariate to adjust for immortal time bias.ResultsA total of 322,870 women who were registered between 2010 and 2011 were included. The user group comprised 0.7% (n = 2,307) of the total population. The mean age was 65.7 ± 8.0 years and 67.2 ± 8.6 years in the user and non-user groups, respectively (p < 0.001). There was no difference in the previous use of estrogen replacement between the 2 groups (p = 0.087). The incidence of breast cancer per 1,000 person-years was 0.49 (n = 8) and 0.68 (n = 1,714) in the user and non-user groups, respectively (hazard ratio [HR], 0.63, 95% confidence interval [CI], 0.32–1.27). HR decreased with increase in the treatment duration, but this change was not statistically significant (HR, 1.00, 95% CI, 0.32–3.11 in 2–3 years; HR, 0.63, 95% CI, 0.20–1.94 in 3–4 years; and HR, 0.41, 95% CI, 0.10–1.65 in 4–5 years).ConclusionLong-term treatment with raloxifene in women with osteoporosis was not significantly associated with a reduction in breast cancer rates. However, further investigation is required for a conclusive proof.