Introduction

Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer-related deaths.¹ Early detection through screening significantly improves survival rates by identifying precancerous polyps or early-stage cancers when they are more treatable.¹

Tubular adenomas are a common type of colorectal polyp. While most remain harmless, they have the potential to turn into cancer over time. This makes early detection and appropriate follow-up essential.¹

This article explains the importance of CRC screening, particularly for patients with tubular adenomas, including risk factors, screening methods, guidelines, barriers to screening, and preventive measures.

Why screening for colorectal cancer is essential

CRC often develops without symptoms in its early stages, making regular screening crucial for early detection. According to the World Health Organization (WHO), CRC accounts for approximately 10% of all cancer cases globally, with nearly 1.9 million new cases diagnosed in 2020 alone.² 

Screening plays a vital role in reducing CRC-related deaths by allowing doctors to detect and remove precancerous polyps like tubular adenomas before they become cancerous.

Risk factors for colorectal cancer with tubular adenomas

Understanding the risk factors can help determine the appropriate screening strategy. While the exact causes of tubular adenomas remain unclear, genetic predisposition and environmental influences play key roles. Some key risk factors include:³

• Age: Most CRC cases occur in individuals over 50 years old, although the rate of cases among younger individuals is increasing
• Family history: Patients with previously detected tubular adenomas have an increased risk of developing CRC, necessitating more frequent screenings
• Diet and lifestyle: High consumption of red and processed meats, low fiber intake, obesity, physical inactivity, smoking, and heavy alcohol consumption contribute to increased risk
• Medical conditions: Individuals with inflammatory bowel disease (IBD), such as Crohn’s disease or ulcerative colitis, are at higher risk
• Genetic syndromes: Conditions like Lynch syndrome or familial adenomatous polyposis (FAP) significantly increase the risk of CRC
• Diabetes and insulin resistance: Type 2 diabetes has been associated with an increased risk of CRC development

Symptoms of colorectal cancer and tubular adenomas

Most tubular adenomas do not cause symptoms and are often found during routine colonoscopies. However, some individuals may experience:⁴

• Rectal bleeding (bright red or dark blood in stool)
• Changes in bowel habits (persistent constipation or diarrhea)
• Unexplained weight loss
• Abdominal pain or cramping
• Mucus in stool
• Signs of anaemia due to blood loss

Since symptoms may not be present, regular screenings, especially for high-risk individuals, are essential for early detection and management.⁴

Colorectal cancer screening methods

Several screening tests are available, each with varying effectiveness, accessibility, and recommendations based on patient risk factors.

Faecal-based tests

These non-invasive tests detect hidden blood or abnormal DNA in stool samples:

• Fecal immunochemical test (FIT): Detects blood in stool, which may indicate CRC or large polyps. It is recommended annually for average-risk individuals
• Guaiac-based fecal occult blood test (gFOBT): Similar to FIT but requires dietary restrictions before the test. Also recommended annually
• Stool DNA test (sDNA-FIT): Combines FIT with genetic testing for DNA mutations associated with CRC. Recommended every three years

Endoscopic procedures

Endoscopic tests provide direct visualisation of the colon and can detect and remove precancerous lesions including tubular adenomas. These include:

• Colonoscopy: Considered the gold standard for CRC screening, colonoscopy examines the entire colon and allows for polyp removal. Recommended every 10 years for average-risk individuals but more frequently for patients with tubular adenomas
• Sigmoidoscopy: Examines only the lower part of the colon and is less invasive than a full colonoscopy. Recommended every 5 years, or every 10 years if combined with FIT testing

Imaging-based tests

These tests use imaging technology to detect abnormalities in the colon. For instance:⁵

• CT colonography (virtual colonoscopy): A non-invasive alternative to colonoscopy that provides detailed images of the colon. Recommended every 5 years

Emerging screening techniques

• Blood-based biomarkers: Researchers are developing blood tests that detect tumor-related DNA and proteins associated with CRC. Some of these tests have shown promising accuracy in early-stage detection⁶
• Artificial intelligence (AI) in colonoscopy: AI-powered tools are being integrated into colonoscopy procedures to improve polyp detection rates and minimize human error⁷

Screening recommendations

Guidelines for CRC screening vary depending on risk factors and individual medical history. 

Average-risk individuals (age 45 and older)

For individuals aged 45 and older with no significant family history or underlying conditions:

• FIT or gFOBT annually
• Stool DNA test every 3 years
• Colonoscopy every 10 years
• CT colonography every 5 years

High-risk individuals

For individuals with a family history of CRC, genetic predisposition, or medical conditions such as IBD:⁸

• Colonoscopy is preferred every 1-5 years, depending on risk level
• Genetic counseling and testing may be recommended for hereditary cancer syndromes

Patients with tubular adenomas

If you have tubular adenomas, the frequency of a colonoscopy depends on the number, size, and type of polyps found:⁹

• 1-2 small adenomas (less than 10mm): Next colonoscopy in 5-10 years
• 3-10 adenomas: Next colonoscopy in 3 years
• More than 10 adenomas: Next colonoscopy in 1 year
• High-risk adenomas (larger than 10mm, certain cell changes, or villous features): Next colonoscopy in 3 years

Regular follow-ups help prevent colorectal cancer by catching any new or concerning polyps early.⁹

Treatment and management of tubular adenomas

The main way to treat tubular adenomas is by removing them during a colonoscopy, which is a procedure called a polypectomy. If the polyps are large or more likely to become cancerous, additional treatments may be needed, such as:

• Endoscopic mucosal resection (EMR): A special method to remove bigger or deeper polyps
• Surgery: If the polyp has cancerous changes or is linked to genetic conditions like familial adenomatous polyposis (FAP) or MUTYH-associated polyposis (MAP), surgery may be required
• Total colectomy: In rare cases where there are too many polyps, doctors may remove the entire colon
• Proctocolectomy with Ileostomy or internal pouch: For people with a high genetic risk, both the colon and rectum may be removed to prevent cancer, with an alternative way created for waste to leave the body¹⁰

Can tubular adenomas come back?

Once a tubular adenoma is removed, it won’t grow back. However, new polyps can still form. Around 30% of people who have had polyps removed will develop more in the future, which is why regular check-ups are important.

You may have a higher risk of developing new polyps if you:

• Are male
• Are over 60 years old
• Have a family history of colon polyps or cancer
• Smoke or drink alcohol often
• Are overweight or obese

Regular screenings and a healthy lifestyle can help lower the chances of new polyps forming.

Barriers to screening and how to overcome them

Even though colorectal cancer (CRC) screening can save lives, many people still don’t get tested. Sometimes, it’s because they don’t know they need to, and other times, it’s because of fear, cost, or access issues. Here’s a closer look at the most common reasons people skip screening, and how to overcome them.¹¹

1. Lack of awareness: Many believe screening is unnecessary without symptoms. Solution: Educate patients about the benefits of early detection
2. Cost and accessibility: Screening can be expensive or difficult to access. Solution: Many programs offer free or low-cost testing
3. Fear and stigma: Many avoid screening due to embarrassment or fear of discomfort. Solution: Reassure patients that modern procedures are safe and well-tolerated

Preventive measures for colorectal cancer

Screening is just one part of preventing colorectal cancer. You can also reduce your risk through lifestyle choices. Here’s how:¹²

• Eat a healthy diet: High fiber and low in red and processed meats.
• Stay physically active: Aim for 30 minutes of activity most days.
• Quit smoking and limit alcohol: Both increase CRC risk
• Maintain a healthy weight: Obesity raises CRC risk
• Adhere to screening schedules: Regular check-ups prevent progression to cancer

Summary

Colorectal cancer screening is a crucial preventive measure that can significantly reduce the incidence and mortality of CRC. Tubular adenomas, while often benign, pose a risk of developing colorectal cancer if left untreated. Regular screenings, lifestyle modifications, and early interventions significantly reduce the risks associated with these polyps. Awareness and proactive management are key to maintaining long-term colorectal health.