Prevention

Colorectal cancer – just like any other cancer – cannot be prevented, but the risk of illness can be lowered through lifestyle changes and by participating in screening.

 

Summary of prevention

  • Bowel cancer cannot be fully prevented, but the risk can be reduced through a healthy lifestyle and by participating in screening.
  • Eating plenty of vegetables, fruits, and fiber-rich food reduces the risk; dairy products and fish may also offer protection.
  • Red meat, processed meat products, and alcohol increase the risk of developing the disease.
  • Physical activity reduces the risk of colon cancer by improving bowel function and the body’s defense mechanisms.
  • A lack of exercise and being overweight can cause metabolic disorders, such as high insulin levels, which promote the growth of cancer cells.
  • Colorectal cancer screening aims to find precancerous lesions or early-stage cancer, and it can reduce mortality from colon and rectal cancer.

Risk Factors

Risk factors generally refer to any individual factors that increase a person’s chances of developing a specific disease, such as cancer. Different cancers have different risk factors. For example, unprotected exposure to strong sunlight is a risk factor for developing skin cancer, and smoking is considered one of the most significant risk factors for lung cancer.

The risk factors for bowel cancer are not yet fully understood, but both environmental factors and genetics are believed to play a role in the development of the tumor. The following is a list of several factors believed to impact the likelihood of developing the disease:

  • Age over 50
  • Being overweight
  • Smoking
  • Alcohol consumption
  • Red meat and processed meat products
  • A diet low in fiber and high in animal fats
  • Lack of physical activity
  • Chronic inflammatory bowel disease, such as ulcerative colitis or Crohn’s disease
  • A history of intestinal polyps
  • A previous diagnosis of colorectal cancer
  • A family history of colorectal cancer

In 2018, the World Cancer Research Fund published a report on the effects of diet, physical activity, and other lifestyle factors on various types of cancer. According to the research data, physical activity, whole grains, fiber, and dairy products reduce the risk of developing bowel cancer.

Stay physically active

Every bit of physical activity benefits your health.

Eat a varied and balanced diet

A fiber-rich diet promotes bowel health.

Take part in screening

Cancer screening can prevent the disease or catch it early.

Heredity

A predisposition to colorectal cancer can be inherited. Approximately 5% of colorectal cancers are hereditary. The most common cause is Lynch syndrome, which predisposes carriers to developing cancer, particularly colorectal cancer, at a young age.

Lynch syndrome is caused by mutations in specific DNA mismatch repair genes, such as MLH1, MSH2, MSH6, and PMS2. This genetic mutation has a 50% chance of being passed from a carrier to their child. While Lynch syndrome primarily predisposes individuals to colorectal cancer, it also increases the risk of endometrial, stomach, urinary tract, ovarian, small intestine, breast, and biliary tract cancers. Depending on the specific gene involved, carrying this mutation carries a 15–46% risk of developing colorectal cancer, a 43–57% risk of developing endometrial cancer, and a 10–17% risk of developing ovarian cancer by the age of 75.

It is estimated that there are over 10,000 mutation carriers in Finland. If a family includes one or more individuals who have developed colorectal or endometrial cancer at a young age, an inherited risk of cancer may be suspected. If Lynch syndrome is known to run in a family, regular screenings are recommended for family members. Through these screenings, a large proportion of cases can be detected at a precancerous or early stage.

More information about Lynch syndrome can be found in the Lynch Syndrome section, written by experts from the Finnish Lynch Syndrome Research Group.

Nutrition

Dietary habits are believed to influence the development of colorectal cancer. A high intake of vegetables and fruit, along with a fiber-rich diet, reduces the risk of developing bowel cancer. Dairy products and fish also appear to have a protective effect, whereas red meat, alcohol, and processed meat products increase the risk of developing the disease.

Physical Activity

Being overweight and a lack of physical activity increase the risk of colorectal cancer. Physical activity stimulates bowel function and reduces the time that harmful substances derived from food remain in the intestines. Exercise also boosts the body’s overall defense mechanisms.

Inactivity and obesity together cause metabolic disorders in the body. One of these disorders is high blood insulin levels, which prevents insulin from working effectively in tissues. This creates favorable conditions for the growth of malignant cells and tissues.

In its 2018 report, the World Cancer Research Fund highlighted physical activity as the most significant factor in reducing the risk of bowel cancer.

Sivu avautuu uudessa ikkunassa↗UKK-instituutti korostaa liikunnan pienentävän syöpäriskiä.

Screening

Colorectal cancer screening was launched in Finland in 2022. The screening currently covers individuals aged 60–72. The program will gradually expand by age group to cover the entire target population—all individuals aged 56–74—starting from 2031. Participants are invited for screening every two years, specifically in the years they turn an even age.

The screening is based on a stool sample collected at home. The use of a blood test in screening relies on the fact that intestinal tumors bleed more frequently than healthy mucosa. In international randomized trials, screening based on detecting fecal occult blood has been shown to reduce colorectal cancer mortality in the average-risk population.

Screening aims to detect asymptomatic precancerous lesions or early-stage cancer.

Colorectal cancer screening

Verkkoluento: Voiko suolistosyöpää ehkäistä?