Colorectal cancer is one of the most commonly diagnosed malignancies and remains a leading cause of cancer-related death in Thailand and worldwide. Of particular concern, it is no longer a disease confined to older adults.

Over the past three decades, the incidence of colorectal cancer among individuals younger than 55 years has increased steadily by approximately 1–2% per year. Currently, one in five patients is diagnosed before the age of 50. Younger patients are often diagnosed at more advanced stages, largely due to the lack of routine and timely screening.

Colorectal cancer typically begins as small polyps arising from the inner lining of the colon or rectum. These precancerous lesions can be detected and removed at an early stage before progressing to invasive cancer. A critical challenge, however, is that early-stage disease is frequently asymptomatic, leading many individuals to seek medical attention only after the disease has advanced.

Early detection enables prevention.

Screening in asymptomatic individuals is the cornerstone of colorectal cancer prevention. It significantly increases the likelihood of curative treatment and reduces avoidable morbidity and mortality.

Colorectal cancer develops as a result of abnormal growth of epithelial cells lining the colon or rectum. In most cases, it originates from a polyp that gradually progresses to cancer over several years if left untreated. The key strength in combating this disease is that it is both preventable and highly treatable when detected early. Its major limitation, however, is the absence of symptoms in its initial stages.

Although no single definitive cause has been identified, colorectal cancer is considered a multifactorial disease involving:

• Genetic mutations in colonic epithelial cells

• Accumulation of adenomatous polyps

• Lifestyle and environmental factors

• Hereditary predisposition

Source
1.https://www.cancer.org/research/acs-research-news/colorectal-cancer-rates-rise-in-younger-adults.html
2. https://www.cancer.org/content/dam/cancer-org/research/cancer-facts-and-statistics/colorectal-cancer-facts-and-figures/colorectal-cancer-facts-and-figures-2023.pdf
3. https://nccrt.org/our-impact/data-and-progress/

Individuals at Increased Risk for Colorectal Cancer Include:

	Adults aged 45 years and older, or those entering the age range associated with increased risk
	Individuals with a family history of colorectal cancer or advanced adenomatous polyps
	Those with a personal history of colorectal polyps or previous colorectal cancer
	Individuals with chronic inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis
	Those experiencing symptoms such as rectal bleeding, changes in bowel habits, persistent abdominal pain, unexplained weight loss, fatigue, or anemia

In its early stages, colorectal cancer is often asymptomatic. As the disease progresses, the following symptoms may develop:

• • Blood mixed with stool or rectal bleeding

  • Passage of bright red blood or dark-colored blood in the stool

  • Narrowed or unusually thin stools

  • Persistent changes in bowel habits, such as alternating constipation and diarrhea

  • Abdominal pain, bloating, or cramping

  • Unexplained weight loss

  • Fatigue and weakness due to iron-deficiency anemia

  • A palpable abdominal mass or persistent tenesmus (a sensation of incomplete bowel emptying)

Individuals experiencing any of these symptoms should seek prompt evaluation by a qualified medical professional for appropriate diagnostic assessment.

Treatment depends on the stage of disease, tumor location, and the patient’s overall health condition. A combination of therapeutic approaches may be recommended to achieve optimal outcomes.

🔹 Surgery

Surgery is the primary treatment, particularly in early-stage disease.

Sphincter-Saving Surgery (SSS) — a minimally invasive laparoscopic technique — aims to remove the tumor while preserving the anal sphincter. This approach allows patients to:

• Have smaller surgical incisions

• Experience faster recovery

• Maintain near-normal bowel function

• Avoid a permanent colostomy bag

• Achieve significantly improved quality of life

🔹 Chemotherapy and/or Radiation Therapy

Chemotherapy and radiation therapy may be used in selected stages of the disease or in combination with surgery. These modalities help reduce tumor size before surgery, lower the risk of recurrence after surgery, and improve overall treatment effectiveness.

A personalized, multidisciplinary treatment plan is essential to ensure the best possible clinical outcomes.

Lifestyle modification plays a significant role in reducing the risk of colorectal cancer. Evidence-based preventive measures include:

• Limiting consumption of grilled, charred, and red meats

• Increasing regular intake of fruits and vegetables

• Engaging in consistent physical activity

• Maintaining a healthy body weight

• Avoiding tobacco use and limiting alcohol consumption

• Undergoing regular colorectal cancer screening as recommended

Colorectal cancer is a disease in which early detection leads to effective treatment and a high likelihood of cure when managed appropriately. Screening in asymptomatic individuals, combined with timely treatment by a multidisciplinary specialist team, significantly improves survival outcomes and enhances quality of life.

Proactive prevention and early intervention remain the most powerful tools in reducing the burden of this disease.