Colorectal Cancer
- Home
- Colorectal Cancer
Colorectal Cancer
(Colon and Rectal Cancer)
What is Colorectal Cancer?
Colorectal cancer is a cancer that starts in the colon (large intestine) or rectum (last part of the colon before the anus). Together, they are referred to as the large bowel or large intestine.
Most colorectal cancers begin as small, non-cancerous growths called polyps, which over time may turn into cancer if not removed. It is one of the most preventable and treatable cancers when detected early through screening.
Types of Colorectal Cancer
- Adenocarcinoma (most common – ~95%)
- Starts in mucus-producing gland cells lining the colon or rectum
- Includes subtypes like mucinous and signet-ring cell carcinoma (more aggressive)
- Carcinoid Tumours – Begin in hormone-producing cells of the intestine
- Gastrointestinal Stromal Tumours (GISTs) – Rare tumours of muscle/connective tissue
- Lymphomas – Cancers of immune cells, occasionally seen in the colon
- Sarcomas – Very rare in the colon/rectum
Symptoms of Colorectal Cancer
Early colorectal cancer may not cause symptoms. When they do appear, they may include:
- Blood in stool or rectal bleeding (bright red or dark)
- Change in bowel habits (diarrhoea, constipation, or narrow stools)
- A persistent feeling of needing to pass stool, even after doing so
- Abdominal discomfort (cramping, pain, or bloating)
- Unexplained weight loss
- Weakness or fatigue
- Iron-deficiency anaemia
- Nausea or vomiting (in advanced cases)
- Feeling of fullness even after small meals
Important: Symptoms can mimic other conditions like piles or IBS. Always consult a doctor if symptoms persist.
Risk Factors for Colorectal Cancer
- Age > 50 years
- Family history of colorectal cancer or polyps
- Inflammatory Bowel Disease (IBD) – Crohn’s or ulcerative colitis
- Sedentary lifestyle
- Obesity
- Diets low in fiber and high in red/processed meats
- Smoking and alcohol consumption
- Type 2 diabetes
- Lynch Syndrome or FAP (Familial Adenomatous Polyposis) – Genetic disorders
- History of colorectal polyps
Diagnosis of Colorectal Cancer
- Screening Tests (for those without symptoms)
- Colonoscopy – Gold standard; visualizes entire colon and removes polyps
- Stool Tests – To detect hidden (occult) blood
- FIT (Faecal Immunochemical Test)
- gFOBT (Guaiac-based faecal occult blood test)
- CT Colonography (virtual colonoscopy)
- Diagnostic Tests (for symptomatic patients)
- Colonoscopy with biopsy – Confirms cancer diagnosis
- Carcinoembryonic Antigen (CEA) – Tumour marker
- CT or MRI of abdomen & pelvis – To assess spread
- PET-CT Scan – For complete staging
Stages of Colorectal Cancer (TNM System)
- Stage 0 (Carcinoma in situ): Only the inner lining is affected
- Stage I: Cancer has grown into the colon wall but not spread
- Stage II: Grown through the wall but not to lymph nodes
- Stage III: Spread to nearby lymph nodes
- Stage IV: Spread to distant organs (liver, lungs, etc.)
Treatment Options at Onco-Life Cancer Centre
Treatment is based on location (colon or rectum), stage, general health, and genetic markers.
Surgery
- Colectomy – Removal of part or entire colon
- Low Anterior Resection (LAR) – For rectal tumours (preserves bowel function)
- Abdominoperineal Resection (APR) – May require permanent colostomy
- Polypectomy or Local Excision – For very early-stage cancers
Chemotherapy
- Common drugs: 5-FU, Capecitabine, Oxaliplatin, Irinotecan
- Used after surgery to kill remaining cells or before surgery to shrink tumors
Radiation Therapy
- Especially for rectal cancer (before or after surgery)
- Can reduce tumour size and recurrence risk
Targeted Therapy
- Drugs that block specific cancer growth pathways (e.g., Bevacizumab, Cetuximab)
- Used in metastatic disease
Immunotherapy
- Especially for patients with MSI-High or Lynch Syndrome cancers
- Drugs like Pembrolizumab may be effective
Supportive Care
- Pain management
- Nutritional support
- Colostomy care and rehabilitation
- Counselling and survivorship programs
Prevention & Early Detection
- Screening after age 45 (or earlier if family history)
- High-fibre, low-fat diet
- Regular exercise
- Avoid red/processed meats
- Limit alcohol and quit smoking
- Maintain healthy weight
- Treat inflammatory bowel diseases early
Colorectal Cancer in India: A Growing Concern
- Increasing due to urban diets, sedentary lifestyles
- Often confused with piles, leading to delayed diagnosis
- Low awareness of preventive colonoscopy screening
Most Popular Questions
Colorectal Cancer
1. Is colorectal cancer curable?
Yes, especially if caught early. Even advanced cases can often be managed effectively.
2. What is the difference between colon and rectal cancer?
Colon cancer affects the large intestine; rectal cancer affects the last part near the anus.
3. At what age should I get a colonoscopy?
Typically at age 45, or earlier if high-risk.
4. Does colorectal cancer always cause bleeding?
Not always. Some patients may have hidden bleeding detected only in stool tests.
5. Is colonoscopy painful?
No. It’s usually done under sedation and is not painful.
6. Can piles cause cancer?
No, but piles can hide cancer symptoms like bleeding. That’s why evaluation is important.
7. What is a polyp?
A small growth on the inner colon lining. Some types (adenomatous) can turn cancerous over time.
8. Can lifestyle changes reverse early-stage cancer?
Lifestyle helps prevent cancer, but early-stage cancer still needs medical treatment.
9. Is surgery always required?
Most cases need surgery. Very early cancers may be treated with endoscopic removal.
10. How long is chemotherapy for colorectal cancer?
Usually 3–6 months, depending on stage and drug combination.
11. What is a colostomy?
An opening (stoma) in the abdomen where stool is passed into a bag. Sometimes temporary.
12. Can colorectal cancer spread?
Yes, commonly to the liver, lungs, or peritoneum.
13. Are there hereditary forms of colorectal cancer?
Yes. Lynch syndrome and FAP are inherited and increase risk significantly.
14. Is radiation needed for colon cancer?
Mostly used for rectal cancer. Not commonly used in colon cancer unless recurrence.
15. What foods help colon health?
Fiber-rich foods: fruits, vegetables, whole grains, legumes.
16. Can vegetarians get colorectal cancer?
Yes, though risk may be lower. Genetics, age, and inflammation still matter.
17. What does CEA mean in reports?
Carcinoembryonic Antigen – a tumour marker used to monitor treatment response or recurrence.
18. Can I live normally after surgery for rectal cancer?
Yes. With proper rehab and diet, most patients adjust well.
19. Is colonoscopy 100% accurate?
It is the most accurate test available, especially when done by an experienced gastroenterologist.
20. Can stress cause colorectal cancer?
Not directly, but chronic stress affects digestion and immunity. It’s best to manage stress for overall health.
