In the early stages of colon cancer, the patient may not experience symptoms or may have non-specific symptoms such as fatigue and weight loss. However, as the disease progresses, the patient may experience symptoms such as abdominal tenderness, bleeding from the rectum, an abdominal mass that can be felt, liver enlargement, and fluid buildup in the abdominal cavity.
The Most Commonly Cited Causes of Colon Cancer are Still Under Investigation
Studies are continually being conducted to prove the link between the following activities and the development of the disease:
- Eating a diet high in red meat and low in fiber, fruits, and vegetables.
- Making poor lifestyle choices such as alcohol and tobacco consumption and not getting enough exercise.
- Maintaining a high body mass index (BMI). This is a calculation that uses an individual’s height and weight to estimate how much body fat they have.
Another cause commonly attributed to an increased risk for colon cancer is the development of ulcerative colitis or Crohn’s disease. The longer an individual has one of these conditions and the greater the level of involvement of the colon, the higher the risk of developing colon cancer.
Asbestos Exposure may be a Factor in Increasing Colon Cancer Risk
There have been a small number of studies that suggest there is a link between the development of colorectal cancer and asbestos exposure; however, it is an area that has not been extensively studied.
One such study, titled “Evidence for Excess Colorectal Cancer Incidence among Asbestos-exposed Men in the Beta-Carotene and Retinol Efficacy Trial”, published November 1, 2005 in the American Journal of Epidemiology, found sufficient evidence to conclude that there is an elevated risk for colorectal cancer in men occupationally exposed to asbestos, especially those with other nonmalignant asbestos-associated conditions.
The researchers spent 10-18 years tracking 3,897 participants in the Beta-Carotene and Retinol Efficacy Trial (CARET) who were occupationally exposed to asbestos.
They found that the risk for colorectal cancer among male heavy smokers exposed to asbestos was 36 percent higher than it was for study participants who were heavy smokers, but who weren’t exposed to asbestos. The other significant finding was that participants who had been diagnosed with asbestos-induced pleural plaques at the start of the study had a 54 percent higher risk for colorectal cancer than other participants. Additionally, the risk of getting the disease increased with worsening pulmonary asbestosis.
Institute of Medicine Report Suggests Possible Link Between Asbestos Exposure and Colorectal Cancer
In June 2006, the Institute of Medicine of the National Academies, which is part of the National Academy of Sciences, released a report titled Asbestos: Selected Cancers, in which the agency assessed whether or not a true causal relationship existed between asbestos exposure and certain cancers, including colorectal cancer. The committee charged with this task evaluated 120 studies before they made their determination. Ultimately, they could not definitively say that asbestos caused colorectal cancer because there wasn’t sufficient evidence; but the evidence that did exist suggested that such a relationship exists.