Colorectal Cancer: A Silent Threat

Context:

This analysis, Written ahead of World Colorectal Cancer Awareness Month, it underscores the rising incidence of colorectal cancer (CRC) globally and in India, emphasising its nature, prevalence, and the critical need for early detection. The piece uses case studies to highlight diagnostic delays, making it a key resource for understanding public health challenges and preventive strategies in India.

1. Definition: Colorectal cancer (CRC) is a malignancy of the large intestine (colon) or rectum, arising from uncontrolled growth of abnormal cells in the mucosal lining.
2. Global Ranking: Third most common cancer worldwide and second leading cause of cancer deaths, with increasing incidence in India due to lifestyle shifts.
3. Origin: Often begins as benign polyps (fleshy growths from the colon’s mucosa), which can turn cancerous over years if undetected or untreated.
4. Types of Polyps: Precancerous polyps include adenomas and serrated polyps; their removal during colonoscopy can prevent CRC development.
5. Symptoms: Includes rectal bleeding, anemia, weight loss, and bowel habit changes; often subtle, leading to late diagnosis (e.g., caecal cancer presenting as anemia in a 65-year-old).
6. Pathophysiology: Triggered by genetic mutations and environmental factors, causing cells to grow uncontrollably and potentially metastasize to organs like the liver.
7. India’s Burden: In 2022, India reported 64,863 cases and 38,367 deaths; age-standardized incidence is 4-6 per 100,000 (men) and 4-5 per 100,000 (women).
8. Risk Factors: Age over 50, family history of CRC/polyps, inflammatory bowel disease (IBD), and genetic syndromes (Lynch, FAP) elevate susceptibility.
9. Early Detection: Screening via colonoscopy identifies and removes polyps, catching CRC early when curable; late stages limit treatment to palliative care.

Key Terms:

• Colorectal Cancer (CRC): Cancer of the colon or rectum originating from mucosal cells.
• Polyps: Benign growths in the colon that may become cancerous if untreated.
• Colonoscopy: Endoscopic exam of the colon to detect and remove polyps or early cancer.
• Adenomas: Common precancerous polyps linked to CRC risk.
• Lynch Syndrome: Genetic condition increasing CRC likelihood.
• FAP: Familial Adenomatous Polyposis, a hereditary syndrome causing multiple polyps.
• Metastasis: Spread of cancer from the colon/rectum to other organs, e.g., liver.

Link To The Original Article – https://www.thehindu.com/sci-tech/health/be-aware-and-beware-of-colorectal-cancer/article69352248.ece