BY.

Gastroenterology and Digestive Endoscopy Team.

In the prevention of colorectal cancer, screening provided by the National Health System for people aged 50 to 69 years plays a key role and is the main tool for early detection. However, it is important not to limit yourself to this appointment: even in previous years, or between checkups, it is crucial to learn to listen to your body’s signals.

Small complaints or seemingly mild symptoms, if interpreted correctly, can make a vital difference in the course of treatment. In this article we will explore the signs not to be overlooked and the importance of a constant preventive approach.

What is colorectal cancer and how prevalent is it today?

Colorectal cancer (or colorectal carcinoma) is a disease that develops due to uncontrolled growth of cells in the inner lining of the large intestine (colon) or rectum. Today it is one of the most common cancers in Italy, with an estimated 48,706 new diagnoses by 2024, including 27,473 among men and 21,233 among women. (Source: AIOM – The numbers of cancer in Italy 2025).

If diagnosed at an early stage (localized stage I or II), colorectal cancer has a 5-year survival of more than 90%.

What are the symptoms and alarm bells not to be ignored?

In the early stages, this condition is often “silent,” and many patients do not experience any relevant complaints. However, some signs should prompt immediate medical attention:

• Persistent changes in bowel habits: sudden constipation, diarrhea, or alternation between the two that lasts for more than 3-4 weeks;
• Light or dark red blood in the stool;
• Abdominal pain or cramping: persistent discomfort, bloating or a sense of fullness;
• Feeling of incomplete emptying;
• Fatigue and weight loss: unexplained chronic fatigue and weight loss for no apparent reason.

Caution: in case of bleeding from the anus, it is always advisable to seek medical attention for proper evaluation.

What role do polyps play in the development of colorectal cancer?

Most of these tumors arise from initially benign formations called adenomatous polyps. Polyps are small growths of the intestinal mucosa that, over time (often over 10-15 years), can undergo cellular transformation and become malignant.

This long interval represents a valuable window of opportunity: detecting and removing a polyp during a colonoscopy means, in effect, eliminating the tumor before it even forms.

Endoscopic polypectomy (i.e., removal of the polyp during colonoscopy) is in most cases resolving, and does not require further surgery.

What are the risk factors and how much does heredity affect them?

Colorectal cancer is a multifactorial disease related to several causes.

Modifiable (lifestyle-related) risk factors:

• Diet high in red and processed meats, low in plant fiber;
• Alcohol consumption (even moderate);
• Cigarette smoke;
• Obesity and overweight (especially visceral adiposity);
• sedentariness;
• diabetes mellitus type 2.

Non-modifiable risk factors:

• age: risk increases progressively after age 50, the threshold at which screening programs become critical;
• Familiarity: having a first-degree relative (parent, sibling or child) who has suffered from this condition can increase the risk by 2-3 times;
• chronic inflammatory bowel disease: conditions such as ulcerative rectocolitis and Crohn’s disease require constant monitoring, especially if colon involvement is extensive;
• personal medical history: having already removed adenomatous polyps or having had previous colorectal cancer increases the likelihood of new formations;
• heredity: about 10 percent of colorectal cancers are related to inherited syndromes transmitted by parents carrying genetic alterations, such as Lynch syndrome or familial polyposis adenomatosis.

If several relatives in the family have had colon cancer or many polyps, especially at a young age, it is important to seek specialized genetic counseling. This signal indicates that there may be a hereditary predisposition, making individualized controls necessary to protect yourself and your loved ones.

What is genetic counseling for and who should request it?

Genetic counseling is a specialized interview aimed at assessing familial risk and identifying whether cancer occurrence is related to an inherited genetic predisposition. It is particularly suitable for:

• People diagnosed with colon cancer at a young age (under 50 years old);
• families with multiple cases of colon, uterine, ovarian, or stomach cancer among close relatives;
• People diagnosed with polyposis (10 or more adenomas).

During genetic counseling, the specialist collects the family oncological history in detail, assesses the likelihood of a hereditary syndrome, and-if indicated-suggests genetic testing (DNA analysis on blood or saliva sample). The test can identify the presence of pathogenic germline mutations in predisposition genes such as MLH1, MSH2, MSH6, PMS2 or APC.

In case of a positive result, the pathway includes intensified endoscopic surveillance, possible predictive genetic testing for healthy family members, and-in selected cases-prophylactic (or preventive) surgery measures.

Genetic counseling is not only indicated for those who have already had cancer: it is also a service for healthy family members who wish to know their risk and take appropriate preventive measures.

Is there a link between nutrition and colorectal cancer?

Yes, diet is one of the most relevant modifiable risk factors for colorectal cancer. The scientific evidence on this issue is solid and derived from decades of epidemiological and experimental studies.

Risks

Processed meats (cold cuts, sausages) are classified as carcinogenic. Excessive consumption of red meat (beef, pork, lamb) and alcohol also significantly increases the risk.

Protection

A diet rich in fiber (fruits, vegetables, legumes, whole grains) speeds up intestinal transit and reduces contact with harmful substances. Calcium and vitamin D also appear to play a protective role.

Practical recommendation: limit red meat consumption to no more than 2-3 times a week, eliminate or drastically reduce cold cuts and sausages, avoid or reduce alcohol, and increase consumption of fruits, vegetables, and whole grains.

Who should be screened and when?

In Italy, the national screening program is free and targeted at the average risk population:

• Age: generally between 50 and 69-70 years (in some regions 45 to 74 years);
• test: faecal occult blood test (FIT), to be repeated every 2 years. This is a simple, noninvasive test that is performed at home by collecting a small stool sample.

Participating in the free NHS screening program is one of the most effective gestures a person can make to protect his or her health. Unfortunately, membership in Italy is still insufficient: less than 50 percent of those invited participate.

If the screening is positive, what are the follow-up examinations?

A positive occult blood result does not necessarily mean you have cancer, but it does require immediate investigation by colonoscopy. This examination allows us to visualize the inside of the colon and, if necessary, immediately remove polyps (polypectomy) or take biopsies. In selected cases or if traditional colonoscopy is not possible, virtual colonoscopy by CT scan can be used.

Early diagnosis makes a difference: at stage IV (metastatic disease), 5-year survival drops to 10-15%. Early diagnosis, however, significantly changes the chances of treatment: detecting the cancer at an early stage provides access to more effective treatments and significantly better prognoses.

How often should screening be repeated if the first result is negative?

If the occult blood test is negative, the National Health Service program requires it to be repeated every two years. On the other hand, if a colonoscopy has been performed with a negative result, the follow-up interval is usually 10 years.

Important: The surveillance interval is always tailored by the gastroenterologist or oncologist based on the specific characteristics of the removed polyps, the quality of the bowel preparation, and the patient’s personal and family history.

The future of early diagnosis: liquid biopsy

Liquid biopsy is one of the most advanced frontiers in diagnostics and research. It consists of a simple blood draw to look for circulating tumor DNA (ctDNA) fragments. The results of preliminary studies are encouraging, but further studies and validation are needed before these tests can be adopted as reliable and standardized screening tools.