Tag Archives: colon and rectal cancer

Vitamin D may lower colon cancer risk

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High blood levels of vitamin D are associated with a lower risk of colon cancer, finds a large European study published online in the British Medical Journal. The risk was cut by as much as 40% in people with the highest levels compared with those in the lowest.High blood levels of vitamin D are associated with a lower risk of colon cancer, finds a large European study published online in the British Medical Journal. The risk was cut by as much as 40% in people with the highest levels compared with those in the lowest.

Several previous studies have already suggested a link between vitamin D and colorectal cancer, but the evidence has been inconclusive with limited information from European populations.

So, researchers from across Europe set out to examine the association between circulating vitamin D concentration as well as dietary intakes of vitamin D and calcium with colorectal cancer risk in Western European populations. Colorectal cancer is the combination of colon and rectal cancer cases.

Their findings are based on the European Prospective Investigation into Cancer Study (EPIC), a study of over 520,000 subjects from 10 Western European countries.

Between 1992 and 1998, participants completed detailed dietary and lifestyle questionnaires and blood samples were collected. The subjects were then tracked for several years, during which time 1,248 cases of colorectal cancer were diagnosed and these were matched to 1,248 healthy controls.

Vitamin D

Vitamin D

Participants with the highest levels of blood vitamin D concentration had a nearly 40% decrease in colorectal cancer risk when compared to those with the lowest levels.


However, some recent publications have suggested maintenance of blood vitamin D levels at 50 nmol/l or higher for colorectal cancer prevention. Thus, the authors also compared low and high levels of blood vitamin D concentration to a mid-level of 50-75 nmol/l. This comparison showed that while levels below the mid-level were associated with increased risk, those above 75 nmol/l were not associated with any additional reduction in colon cancer risk compared to the mid-level.

Although the results support a role for vitamin D in the etiology of colorectal cancer, the authors caution that very little is known about the association of vitamin D with other cancers and that the long term health effects of very high circulating vitamin D concentrations, potentially obtained by taking supplements and/or widespread fortification of some food products, have not been well studied.

With respect to colorectal cancer protection, it is still unclear whether inducing higher blood vitamin D concentration by supplementation is better than average levels that can be achieved with a balanced diet combined with regular and moderate exposure to outdoor sunlight, they say.

The findings of previous randomised trials have been inconsistent. As such, new trials should be carried out to evaluate whether increases in circulating vitamin D concentration can effectively reduce colorectal cancer risk without inducing serious adverse events, they conclude. Currently, the best recommendation to reduce ones risk of colorectal cancer is to stop smoking, increase physical activity, reduce obesity and abdominal fatness, and limit intakes of alcohol and red and processed meats.

New genes linked to colon cancer

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Previously, only a few genes had been associated with the formation of metastases in colorectal cancer. Now, researchers of the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch and Charité – University Medicine Berlin, Germany, have identified 115 genes that are disregulated both in the primary tumor and in its metastases. In the future, their findings may help identify patients with aggressive tumors at an earlier stage.

The National Cancer Institute estimates that, alone in the United States, 106,100 cases of colon cancer will occur and 49,920 patients will die both from colon and rectal cancer in 2009.

Beginning in glands in the bowel lining, colorectal cancer often remains undiscovered initially. “However, the main problem is not the primary tumor,” explained the surgeon and clinical researcher Dr. Johannes Fritzmann, “but the dangerous metastases.”

Colon cancer

Colon cancer

Metastases arise when single cells break off from the primary tumor and spread to other body regions via the blood vessels or the lymphatic system. In colorectal cancer, these cells usually settle in the liver, lungs, or lymph nodes. Since the affected patient seldom feels pain or shows other symptoms, the tumor is frequently not discovered until it has already formed metastases.

To investigate which genetic mutations favor the formation of metastases, the researchers analyzed 150 tissue samples of colorectal cancer patients with and without metastases. The researchers identified 115 genes that are falsely regulated in both the primary tumors and their metastases. In this way, the researchers succeeded in identifying a genetic signature which distinguishes tumors with metastatic potential from those that do not metastasize.


Of the 115 genes the researchers identified, they focused on one gene in particular: BAMBI. They discovered that this gene is more active in metastatic tumors and metastases than in non-metastatic tumors.

“Our investigations show that the particular gene BAMBI is associated with two import signaling pathways and thus promotes metastasis formation,” Dr. Fritzmann said. “These signaling pathways (Wnt and TGF-beta) are, among other things, important in the developing embryo.”

In the future the researchers want to investigate the role of the other 114 genes more closely, in order to better understand the individual steps of metastasis formation.

Dr. Fritzmann hopes the research findings will help determine early on whether a tumor has metastatic potential. The doctors could then adapt the therapy accordingly.