Healthy Lifestyle Improves Colorectal Cancer Outcomes

Physical activity and healthy lifestyle reduce the risk of developing colorectal cancer.

by C.H. Weaver M.D.

Lifestyle risk factors for colorectal cancer include obesity, physical inactivity, smoking, heavy alcohol consumption, a diet high in red or processed meats, and a diet inadequate in fruits and vegetables. Fortunately, these are risk factors that can be changed. Women who have any of these lifestyle risk factors can consult their physician or nutritionist about adjusting their lifestyle to reduce their colorectal cancer risk and optimize their overall health and well-being.

The researchers discuss several possible causes for the rise, including rising rates of obesity, which is a risk factor for colon cancer. Dietary factors may also play a role. The researchers note that between the late 1970s and the mid-1990s, fast-food consumption in the United States increased fivefold among children and threefold among adults. A diet high in fast food is associated with both greater meat consumption and reduced milk consumption.

Dr. Allyson Ocean M.D. discusses the latest developments in screening, early detection & treatment of colorectal cancer.

Allyson J. Ocean, MD
Medical Oncologist, Jay Monahan Center for Gastrointestinal Health
Medical Oncologist, Solid Tumor Service, NewYork-Presbyterian Hospital
Assistant Professor of Clinical Medicine, Weill Medical College of Cornell University

Increased consumption of red and processed meat has been shown to increase the risk of cancers of the distal colon and the rectum, whereas milk and calcium consumption have shown a protective effect against left-sided tumors in which the rise in incidence was most prominent. They say it is plausible that unfavorable dietary patterns in children and young adults over the past three decades may have contributed to the increase in colorectal cancer among young adults observed in the study.

The authors conclude: “The disparate increase in left-sided colorectal cancer suggests that particular attention be given to studies to elucidate the behavioral and environmental risk factors responsible for this trend and potential prevention and early detection strategies.”

Due to the high prevalence of this cancer, prevention and early detection are important areas of research. Two recent studies suggest that making healthy lifestyle choices can reduce the likelihood of developing cancer or postpone the age at which cancer develops.

The first study evaluated the impact of alcohol and tobacco use on age at colorectal cancer diagnosis.1Researchers assessed information from more than 160,000 colorectal cancer patients. Alcohol and tobacco use were classified as current, past, or never.

  • Current use of alcohol or tobacco was linked with a younger age at colorectal cancer diagnosis.
  • Among those who were current users of both alcohol and tobacco, the average age at colorectal cancer diagnosis was 63 years. This was almost eight years younger than the average age at colorectal cancer diagnosis among individuals who never smoked or drank.

The researchers suggest that in the future, it may be possible to use information about a variety of factors—including alcohol and tobacco use—to individualize colorectal cancer screening guidelines. Optimizing colorectal cancer screening is important because screening can both detect colorectal cancer at an early stage, when it is most curable, and can also prevent colorectal cancer by detecting precancerous colorectal changes.

A second study assessed the impact of fruit and vegetable intake on the risk of developing colorectal polyps.2 Colorectal polyps are small growths within the colon or rectum that are thought to be precursors to cancer. While other dietary factors have been found to influence colorectal cancer risk (high red meat intake, for example, appears to increase risk), the evidence regarding a possible protective role of fruit and vegetable intake has been less consistent.

To evaluate the link between fruit and vegetable intake and colorectal polyps, Researchers affiliated with the Nurses’ Health Study evaluated the link between diet and polyps among more than 34,000 women who had undergone a colonoscopy or sigmoidoscopy between 1980 and 1998. The study suggested that a diet high in fruit may reduce the risk of developing colorectal polyps:

  • Compared to women who ate one or fewer servings of fruit per day, women who ate five or more servings of fruit per day were 40% less likely to develop colorectal polyps.
  • There was little evidence that high vegetable intake reduced the risk of colorectal polyps.

Coupled with earlier studies that show that physical activity reduces colorectal cancer risk, these studies provide further evidence that healthy lifestyle choices reduce the risk of developing colorectal cancer and improve colorectal cancer outcomes.

byCancer ConnectDec 3, 2009

High Fruit and Veggie Intake Reduces Development of Colorectal Adenomas in Women

According to an article recently published in Cancer Research, high consumption of fruit and vegetables significantly reduces the incidence of colorectal polyps among women.

Colorectal cancer is the second leading cause of cancer-related deaths in the U.S. Due to its prevalence, extensive research is aimed at uncovering variables that may help reduce or prevent the rate at which it develops.

Colorectal polyps are small growths within the colon or rectum that are thought to be precursors to cancer. Therefore, a reduction in the rate of polyps could ultimately reduce the rate of colorectal cancer.

Researchers affiliated with the Nurses’ Health Study (NHS) recently evaluated the effects of diet on the incidence of colorectal polyps among women. This study included over 34,000 women who had undergone a colonoscopy or sigmoidoscopy between 1980 and 1998. The study also included histories of dietary information for the participants.

  • Women who ate five or more servings of fruit per day had a 40% reduced incidence of colorectal polyps.
  • Women who ate five or more servings of vegetables per day had a 38% reduced incidence of colorectal polyps.
  • Women who ate four or more servings of legumes per week had a 33% reduced incidence of colorectal polyps.

The researchers concluded that a high intake of fruit and/or vegetables significantly reduces the risk of colorectal polyps in women. These results support other studies indicating an association between fruit and vegetable intake and the reduction of various types of cancers.

Reference: Michels KB, Giovannucci E, Chan AT, et al. Fruit and vegetable consumption and colorectal adenomas in the Nurses’ Health Study. Cancer Research. 2006;66:3942-3953.

Alcohol and Tobacco Use Linked with Younger Age at Colorectal Cancer Diagnosis

A study published in the Archives of Internal Medicine reports that current users of alcohol and tobacco are diagnosed with colorectal cancer at a younger age than non-users of alcohol and tobacco. If confirmed, these findings could influence screening recommendations.

Colorectal cancer is the second leading cause of cancer-related deaths in the U.S. The disease develops in the large intestine, which includes the colon (the longest part of the large intestine) and the rectum (the last several inches).

Screening for colorectal cancer can detect cancer at an early stage and can also prevent cancer by allowing physicians to detect and remove precancerous polyps. Screening tests for colorectal cancer include colonoscopy, sigmoidoscopy, and the fecal occult blood test.

Some individuals, such as those with certain hereditary cancer syndromes, have an increased risk of developing colorectal cancer at an early age. These individuals generally begin colorectal cancer screening a younger age than average-risk individuals. There is less information, however, about whether non-genetic factors, such as smoking and alcohol use, should also influence screening recommendations.

To evaluate the relationship between alcohol and tobacco use and age at colorectal cancer diagnosis, researchers evaluated a database containing information about more than 160,000 colorectal cancer patients. Alcohol and tobacco use was classified as current, past, or never.

  • Current use of alcohol or tobacco was linked with a younger age at colorectal cancer diagnosis.
  • Among those who were current users of both alcohol and tobacco, the average age at colorectal cancer diagnosis was 63 years. This was almost eight years younger than the average age at colorectal cancer diagnosis among individuals who never smoked or drank.
  • Use of alcohol and tobacco also appeared to influence the location of the colorectal cancer. Users of alcohol and/or tobacco were more likely than non-users to have distal cancers (cancers in the rectum or the lower part of the colon). This suggests that sigmoidoscopy, which only evaluates the lower part of the colon and the rectum, may miss fewer cancers in those who use alcohol and tobacco than in those who do not.
  • Gender also influenced age at colorectal cancer diagnosis and location of colorectal cancer. Men were diagnosed with colorectal cancer at a younger age than women, and were more likely to have distal cancers.

The researchers conclude that alcohol use, tobacco use, and male gender are linked with earlier onset and distal location of colorectal cancer. The researchers note that in the future, it may be possible to use information about a variety of factors-such as alcohol and tobacco use, age, body mass index, diet, calcium consumption, and hereditary factors-to individualize colorectal cancer screening guidelines.

Reference: Zisman AL, Nickolov A, Brand RE et al. Associations Between Age at Diagnosis and Location of Colorectal Cancer and the Use of Alcohol and Tobacco. Archives of Internal Medicine. 2006;166:629-634.

Heart Disease and Diabetes Increase Risk of Colorectal Cancer

According to results presented at the 2006 Digestive Disease Week meeting, individuals who are diabetic or those with coronary artery disease have an increased risk of developing colorectal cancer.

Colorectal cancer is the second leading cause of cancer-related deaths in the U.S. If detected and treated early, cure rates for colorectal cancer are high. However, once the cancer has spread from its site of origin, cure rates fall dramatically.

Adenomas are growths that are considered pre-cancerous. During a procedure for the screening of colorectal cancer, such as a colonoscopy, physicians will remove adenomas to reduce the possibility of their turning cancerous.

Screening for colorectal cancer is recommended beginning at the age of 50, or earlier for those with a family history of the disease. Research continues to evaluate possible variables that may influence the risk of developing colorectal cancer. Individuals at a higher risk may benefit from more frequent screening so that their disease may be detected in its earliest stages.

Researchers from Washington University in St. Louis recently conducted a clinical study to evaluate the rates of colorectal cancer in women with diabetes.[1] This study included 100 women with diabetes and 500 women who did not have diabetes.

  • 37% of women with diabetes had an adenoma, versus 24% for those who were not diabetic.
  • 14% of women with diabetes had advanced adenomas, compared with 6% of women without diabetes.
  • At 42%, obese women with diabetes had the highest incidence of adenomas, and non-obese, non-diabetic women had the lowest rate of adenomas (23%).

Researchers from the University of Hong Kong also conducted a study to evaluate the risk of heart disease on the development of adenomas of the colon.[2] This study included 307 patients; nearly half of the patients (46.3%) had coronary artery disease.

Colorectal cancer was diagnosed in 30.3% of patients with heart disease, compared with 19.4% of patients without heart disease.

16.9% of patients with heart disease had advanced colorectal cancer, compared with only 6.7% of patients without heart disease.

Researchers from both of these trials have stressed that colorectal cancer is increased in patients with diabetes and heart disease. They recommend screening for these groups of patients. Patients with diabetes or heart disease may wish to speak with their physician regarding their individual risks and benefits of undergoing screening for colorectal cancer.

References:

[1] Elwing J, et al .Type 2 Diabetes Mellitus: The Impact on Colorectal Adenoma Risk in Women. Proceedings from the Digestive Disease Week meeting. May 2006. Abstract 1245

[2] Chan A, et al. Patients with coronary artery disease are at high risk for developing colorectal cancer and adenoma: an interim analysis of a prospective study. Proceedings from the Digestive Disease Week meeting. May 2006. Abstract 208.

Smoking Linked to an Increased Risk of Colorectal Cancer.

Long-term smoking significantly increases the risk of colorectal cancer, according to a study by American Cancer Society (ACS) researchers that was recently published in the Journal of the National Cancer Institute.

Colorectal cancer is not currently on the list of smoking-related cancers, although smoking has consistently been associated with colorectal polyps. However, the results of this study may support the addition of colorectal cancer to the list of eight other cancers caused by smoking (lung, mouth, pharynx, larynx, esophagus, pancreas, kidney and bladder).

In an effort to determine a relationship between smoking and colorectal cancer, the ACS researchers examined 14 years of data (1982-1996) collected from the Cancer Prevention Study II (CPS II). They evaluated the smoking patterns of 312,332 men and 469,019 women as reported by these participants when they entered the study in 1982. The researchers found that colorectal cancer death rates were highest among current smokers, intermediate among former smokers and lowest among never smokers. The risk of dying from colorectal cancer was higher among those who smoked for 20 or more years.

The duration and amount of smoking was a significant factor, as the data showed that the risk of colorectal cancer increased with the number of cigarettes smoked daily and the number of years of smoking. A younger age at initiation also increased the risk. On the other hand, the colorectal cancer risk decreased with each year after quitting smoking. The data also showed that cigar and pipe smokers had an increased risk of colorectal cancer as well.

Since the data showed that the risk of dying from colorectal cancer increased with the duration and amount of smoking, the researchers concluded that there might be a causal relationship between smoking and colorectal cancer. If this causal relationship does indeed exist, then approximately 12% of colorectal cancer deaths in the U.S. in 1997 were attributable to smoking.

More research is necessary to determine the relationship between smoking and colorectal cancer; however, the results of this study indicate that current and former smokers may want to consider more frequent screening tests for colorectal cancer. Currently, the recommended screening tests include the fecal occult-blood test (FOBT), sigmoidoscopy, colonoscopy and the double-contrast barium enema. People concerned with screening for this disease or who may be interested in smoking cessation programs can consult with their physicians for more information. (Journal of the National Cancer Institute, Vol 92, No 23, 2000)

References:

1 Zisman AL, Nickolov A, Brand RE et al. Associations Between Age at Diagnosis and Location of Colorectal Cancer and the Use of Alcohol and Tobacco. Archives of Internal Medicine. 2006;166:629-634.2 Michels KB, Giovannucci E, Chan AT, et al. Fruit and vegetable consumption and colorectal adenomas in the Nurses’ Health Study. Cancer Research. 2006;66:3942-3953.

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