AICR ScienceNow
Volume 12
Spring 2005
Inflammation is commonly known as a response to infection and tissue damage. However, accumulating evidence links inflammation with several types of cancer, including colorectal cancer. For example, patients with ulcerative colitis and inflam-matory bowel disease, which are condi-tions with high levels of inflammation, have an increased risk for this type of cancer.
Low-grade chronic inflammation resulting from other conditions like type 2 diabetes mellitus and obesity may also contribute to colorectal cancer. Elizabeth Platz, Sc.D., M.P.H., an epidemiologist at Johns Hopkins University, and her col-leagues have already analyzed evidence and concluded that a person's Body Mass Index (BMI) positively correlates with colon cancer. AICR has been funding Dr. Platz's research in this area since January 2001.
The Activity of Fat Cells
Dr. Platz believes that being overweight affects colorectal cancer risk in several ways. "Fat cells or adipocytes, rather than being metabolically inactive," she says, "do actively increase inflammation in several interrelated ways." Adipocytes produce and secrete factors that influence insulin resistance and inflammation. These problems could lead to DNA damage and enhance cell proliferation.
Recently, Dr. Platz collaborated with researchers at Johns Hopkins and Harvard Medical School on a study related to her AICR research. They found that C-reactive protein (CRP) blood levels were elevated among persons who later developed colon cancer. CRP is produced by the liver in response to interleukin 6 (IL-6), which is secreted by white blood cells, as well as adipocytes. "Insulin and stress can induce adipocytes to produce more IL-6," says Dr. Platz. "This may explain why obese indivi-duals have higher levels of IL-6 and CRP."
In her current study funded by AICR, Dr. Platz is investigating whether other specific substances made by fat cells that contribute to insulin resistance and the inflammatory response are linked to the development of colorectal cancer. Dr. Platz has already observed that people who have poor insulin and glucose control or type 2 diabetes mellitus have a greater risk for colorectal cancer. These conditions are strongly associated with excess weight.
She is also investigating how the diet, especially a high intake of calories and low intake of vegetables, fruits and fiber - which can contribute to overweight - is associated with colorectal cancer.
Measuring the Risk of Cancer
One possible application of Dr. Platz's research is the ability to identify people at higher risk of colon cancer. "By measuring markers of inflammation such as CRP, we could potentially screen individuals who are at risk of developing colon cancer and intervene with dietary and lifestyle modifications to prevent this development," she hopes.
Secondly, by better understanding how overweight and obesity impact inflam-mation and insulin resistance, Dr. Platz points out, "opportunities for cancer prevention are much greater. We could possibly decrease inflammation and improve insulin sensitivity by dietary and lifestyle modifications that reduce weight." She also claims, "Findings from this type of research may strengthen the public health message about avoiding obesity."
References
Saydah SH et al. Association of markers of insulin and glucose control with subsequent colorectal cancer risk. Cancer Epidemiol Biomarkers Prev. 2003;12:412-8.
Erlinger TP et al. C-reactive protein and the risk of incident colorectal cancer. JAMA. 2004;291:585-90.
All active news articles
Volume 12
Spring 2005
Can Overweight Inflame Colorectal Cancer Risk?
Inflammation is commonly known as a response to infection and tissue damage. However, accumulating evidence links inflammation with several types of cancer, including colorectal cancer. For example, patients with ulcerative colitis and inflam-matory bowel disease, which are condi-tions with high levels of inflammation, have an increased risk for this type of cancer.
Low-grade chronic inflammation resulting from other conditions like type 2 diabetes mellitus and obesity may also contribute to colorectal cancer. Elizabeth Platz, Sc.D., M.P.H., an epidemiologist at Johns Hopkins University, and her col-leagues have already analyzed evidence and concluded that a person's Body Mass Index (BMI) positively correlates with colon cancer. AICR has been funding Dr. Platz's research in this area since January 2001.
The Activity of Fat Cells
Dr. Platz believes that being overweight affects colorectal cancer risk in several ways. "Fat cells or adipocytes, rather than being metabolically inactive," she says, "do actively increase inflammation in several interrelated ways." Adipocytes produce and secrete factors that influence insulin resistance and inflammation. These problems could lead to DNA damage and enhance cell proliferation.
Recently, Dr. Platz collaborated with researchers at Johns Hopkins and Harvard Medical School on a study related to her AICR research. They found that C-reactive protein (CRP) blood levels were elevated among persons who later developed colon cancer. CRP is produced by the liver in response to interleukin 6 (IL-6), which is secreted by white blood cells, as well as adipocytes. "Insulin and stress can induce adipocytes to produce more IL-6," says Dr. Platz. "This may explain why obese indivi-duals have higher levels of IL-6 and CRP."
In her current study funded by AICR, Dr. Platz is investigating whether other specific substances made by fat cells that contribute to insulin resistance and the inflammatory response are linked to the development of colorectal cancer. Dr. Platz has already observed that people who have poor insulin and glucose control or type 2 diabetes mellitus have a greater risk for colorectal cancer. These conditions are strongly associated with excess weight.
She is also investigating how the diet, especially a high intake of calories and low intake of vegetables, fruits and fiber - which can contribute to overweight - is associated with colorectal cancer.
Measuring the Risk of Cancer
One possible application of Dr. Platz's research is the ability to identify people at higher risk of colon cancer. "By measuring markers of inflammation such as CRP, we could potentially screen individuals who are at risk of developing colon cancer and intervene with dietary and lifestyle modifications to prevent this development," she hopes.
Secondly, by better understanding how overweight and obesity impact inflam-mation and insulin resistance, Dr. Platz points out, "opportunities for cancer prevention are much greater. We could possibly decrease inflammation and improve insulin sensitivity by dietary and lifestyle modifications that reduce weight." She also claims, "Findings from this type of research may strengthen the public health message about avoiding obesity."
References
Saydah SH et al. Association of markers of insulin and glucose control with subsequent colorectal cancer risk. Cancer Epidemiol Biomarkers Prev. 2003;12:412-8.
Erlinger TP et al. C-reactive protein and the risk of incident colorectal cancer. JAMA. 2004;291:585-90.
All active news articles