A new study suggests that the nutrients calcium and vitamin D work together, not separately, to reduce the risk of colorectal cancer.
Maria V. Grau, M.D., of the Dartmouth Medical School in Lebanon, N.H., and her colleagues examined data on 803 people who participated in the Calcium Polyp Prevention Study, a randomized trial that showed a protective effect of calcium supplementation for preventing the recurrence of colorectal cancer. The new study found that calcium supplements reduced the risk of recurrence only among individuals with baseline vitamin D levels above the median (29.1 ng/mL). Similarly, serum vitamin D levels were associated with reduced adenoma recurrence only among individuals taking calcium supplements.
These findings "provide a strong indication that vitamin D and calcium have a joint antineoplastic effect in the large bowel," the authors write, but they add that "further investigation is needed to understand the mechanistic basis of the vitamin D/calcium interaction and to clarify the amount of intake of each nutrient required for optimum protective effect."
Contact: Andy Nordhoff, Dartmouth Medical School, 603-650-1492, dms.communications@dartmouth.edu.
Regular Aspirin Use Associated with Reduced Risk of Stomach Cancer
Regular use of nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, is associated with a reduced risk of a specific type of gastric (stomach) cancer, according to a review of past studies.
Gastric cancer is the fourth most common cancer and the second leading cause of cancer deaths worldwide. Benjamin Chun-Yu Wong, M.D., of the University of Hong Kong, Queens Mary Hospital, and his colleagues reviewed data from nine studies, which included 2,831 patients with gastric cancer, and found that long-term use of aspirin or nonaspirin NSAIDs is associated with a dose-dependent reduction in the risk of gastric cancer. Further analysis showed that NSAID use was associated with a reduced risk of noncardia gastric cancer, but not of gastric cancer at the cardia (the opening of the esophagus into the stomach).
Contact: Dr. Benjamin Wong, University of Hong Kong, bcywong@hku.hk.
Type 1 Diabetes Associated with Increased Risk of Cancer
A Swedish study has found an increase in overall cancer incidence among people with type I diabetes compared with the general population in Sweden. The study also found that the increased risks of specific cancers associated with type 1 diabetes differed from those associated with type 2 diabetes.
The study, conducted by Kazem Zendehdel, and Weimin Ye, M.D., of the Karolinska Institute in Stockholm, and colleagues, involved 29,187 Swedish patients who were hospitalized for type 1 diabetes from 1965 through 1999. There were 355 new cases of cancer among the type 1 diabetes patients, which corresponded to a 20% increase in overall cancer incidence compared with the cancer incidence in the general population of Sweden. Patients hospitalized for type 1 diabetes had more than twice the relative risk of stomach and endometrial cancer than the general population, as well as an increased risk of cervical cancer.
Contact: Ulla Bredberg-Rådén, Karolinska Institute, 46-8-524-86389; ulla.bredberg-raden@admin.ki.se.
Human Papillomavirus Associated with Cancers of the Oropharynx
The same strain of the human papillomavirus (HPV) that is most commonly found in cervical cancer may play a role in cancers of the oropharynx and the oral cavity, according to a new study.
Rolando Herrero, M.D., Ph.D., of the Proyecto Epidemiológico Guanacaste in Costa Rica, and his colleagues from the International Agency for Research on Oral Cancer Study Group, tested for HPV DNA in tissue samples from 1,670 case patients with cancers of the oral cavity and oropharynx and 1,732 control patients without cancer.
They detected HPV DNA in 3.9% of cancers of the oral cavity and 18.3% of cancers of the oropharynx. Most of the case patients that tested positive for HPV DNA were infected with HPV16, which is the most common HPV type in cervical cancer. The authors say more research is needed to determine how HPV is transmitted to the oral cavity.
Review Focuses on Epigenome in Cancer Chemoprevention
Epigenetic changes, or alterations in gene expression, promote the development of cancer; these changes can be reversed with small molecules, making the epigenome a promising target for cancer chemoprevention. In a review article, Levy Kopelovich, Ph.D., of the National Cancer Institute, and colleagues describe epigenetic changes in high-risk tissues, such as the colorectum, breast, and prostate that could serve as targets for chemoprevention. They also examine epigenetic strategies to preventing cancer, including the use of DNA methyltransferase inhibitors and the combined use of epigenetic drugs with agents that target reactivated genes. The authors conclude that, "permutations of these approaches and continued advancement in understanding the mechanisms involved in epigenetic regulation and how they interact with genetic changes during tumor progression will facilitate development of newer, more efficacious, and safer chemoperventive agents."
Contact: NCI Press Office, 301-496-6641, ncipressofficers@mail.nih.gov.
Titles of additional articles appearing in the December 3 JNCI:
- Active tamoxifen metabolite plasma concentrations after coadministration of tamoxifen and the selective serotonin reuptake inhibitor paroxetine: http://www.eurekalert.org/emb_releases/2003-12/jotn-hfd112403.php
- Prostate-specific antigen screening in elderly men: http://www.eurekalert.org/emb_releases/2003-12/jotn-emr112403.php
Note: The Journal of the National Cancer Institute is published by Oxford University Press and is not affiliated with the National Cancer Institute. Attribution to the Journal of the National Cancer Institute is requested in all news coverage.
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