Colorectal cancer; screening and prevention

Colorectal cancer is an acceptable term used for malignant tumors of the large and rectal intestine
(Image: © Institut national du cancer/Unsplash)

Colorectal cancer is an acceptable term used for malignant tumors of the large and rectal intestine (Rectum), where these tumors are treated as one disease even though they differ from each other from a biological and therapeutic point of view.

Colon cancer develops from the cells that line the inner lining of the colon. In more than 80% of cases, it is an adenomatous polyp that has slowly evolved. It is estimated that more than 42,000 colon and rectal cancers were detected in 2012.

The patient will receive a choice of treatments according to his situation. Surgery is the main treatment, and potentially the chemotherapy will complete the operation after an additional examination in order to reduce the risk of recurrence.

Screening is an effective way to fight colorectal cancer. If blood is present in the stool during the screening test, the doctor will perform a colonoscopy, making it possible to detect rectal cancer at an early stage, more easily treated, or to identify benign lesions before they progress to cancer.

A recent study validated the necessity of carrying out early detection of colorectal cancer at the age of 45 to reduce the high rates of death caused among adults.

1. The study and results

Researchers have conducted the study. And they presented their results in the Gastroenterology Conference which took place in Barcelona, Spain.

The researchers followed up the case of 6,027 people and found a 40 % increase in polyps in colon tissues, which could turn into malignant tumors if not treated in patients between 45 and 49 years old compared to patients between 40 and 44 years old.

The researchers also found that the rate of tumor discovery was 8 % higher in people between 45 and 49 years old, and this rate was previously among people between 50 and 54 years old.

The leader of the research team, Dr. David Karsenty, a specialist in digestive and liver diseases, said that the results of the study make it imperative to detect colorectal cancer tumors between the ages of 45 and 49 years, instead of the age of 50 to 54 years.

Besides, these results show that, at the age of 45, there is an increased observation of polyps in the colon and rectal tissues, requiring treatment before they turn into malignant tumors.

2. Lifestyle risk factors

2.1 Age-related risk factor

90% of colorectal cancers diagnosed from the age of 50. The risk of developing colorectal cancer in the population aged 50 to 74 with no other risk factor than age has been estimated at 3.5%.

Age over 50 is the main risk factor for colorectal cancer.

2.2 Alcohol consumption

Alcohol consumption increases the risk of colorectal cancer by 9% from one drink per day. The risk increases with the amount, and the effect depends on the total amount of alcohol

consumed and not the type of alcohol.

The mechanisms involved are folate deficiency and the transformation of alcohol into acetaldehyde (molecule carcinogenic) by the colonic microbiota. Alcohol classified in group 1 and known as carcinogenic nutritional agents for the man.

2.3 Smoking

Tobacco is an independent factor from alcohol for the risk of adenoma and colorectal cancer. The risk of colorectal cancer is even higher than the number of years of smoking, the number of cigarettes/day and the number of packages/years is high: the Odds ratio (OR) is between 1.08 and 1.44 (meta-analysis including 36 prospective studies corresponding to 3 million subjects) 11.

2.4 Overweight and obesity

For an increase in the body mass index (BMI) of 5 kg / m2. The percentage of risk increase of colorectal cancer estimated at 15%. In an obese person (BMI> 30 kg / m2), the increased risk is 33% compared to a person with a BMI between 18 and 25 kg / m2) (SIGN).

A significant increase in risk is also observed with the increase in abdominal adiposity (whether measured by the waist/hip ratio or simply by the waist). The mechanisms involved are the increase in endogenous levels of certain hormones and growth factors (insulin, sex hormones, leptin, insulin-like growth factor-1 [IGF-1]), which are involved in functions biological agents playing an important role in carcinogeneses such as proliferation, differentiation, and cell metabolism. Obesity induces a chronic inflammatory state (increased blood levels of pro-inflammatory factors such as tumor-necrosis factor-α (TNFα), interleukin 6 (IL-6), C-reactive protein) as well as leptin, which promote cell proliferation.

2.5 Consumption of meat and cold meats

Consumption of red meats (beef, veal, mutton, lamb, pork, goat). And cold meats (meats preserved by smoking, drying, salting or adding preservatives) increases the risk of colorectal cancer.

The risk is increased by 29% per serving of meat consumed of 100 g / day and by 21% per serving of 50 g delicatessen/day.

The mechanisms involved and linked to the addition of nitrites (charcuterie) or the production of N-nitroso compounds carcinogens, free radicals, and pro-inflammatory cytokines linked to excess heme iron. Nitrites ingested are classified in group 2 of agents, probably carcinogenic to humans.

3. Screening and prevention of colorectal cancer

3.1 Screening

We advise for colorectal cancer screening starting at the age of 45. It involves two separate procedures.

3.1.1 A community organized screening program: offered as part of a national screening campaign targeted at age (50-74 years) by a test for occult blood in the stool. As part of this program, the screening test makes it possible to sort out from an apparently healthy target population of men or women with occult stool bleeding and, therefore, at risk for colorectal cancer.

3.1.2 An opportunistic individual screening: a man or a woman being invited to a test during his use of care service, the consultant doctor having identified in the latter:

  • A personal or family history of over-risk of colorectal cancer;
  • Functional signs requiring the implementation of the individual screening procedure by colonoscopy.

Screening plays an essential role in the prognosis and progression of cancer. Discovered early, it offers a good chance of recovery.

3.2 Prevention

The prevention of colorectal cancer involves changing lifestyle habits.

  • Stop smoking and limit the consumption of alcoholic beverages; the association alcohol + tobacco

multiple by 8.6 the risk of colorectal cancer.

  • Limit the consumption of red meats (intake ≥ 100 g / day increases by 29% the risk of colorectal cancer) and restrict the consumption of cold meats (intake ≥ 50 g / day increases the risk of colorectal cancer by 21%).
  • Increase the intake of dietary fiber: green vegetables, pulses, and low-grain processed (400 g / day).
  • Augment the consumption of dairy products: milk is associated with likely to decrease the risk of colon cancer.
  • The increase of physical activity (example: 30 min/day –  5 days/week, a moderate activity like walking fast). The percentage decrease in the risk of colon cancer according to the type of physical activity, which varies from 18% to 29%.
  • Maintain your weight within the limits of a healthy weight; that is to say, a body mass index (BMI) between 25 and 27 kg / m2. The risk is increased by 15% for an increase of BMI> 5 kg / m2.

 

Originally published on Live Positively.