Introduction
Colorectal cancer is the third most common cancer in India and increasingly affects adults under 50. The good news is that caught early it is one of the most curable solid cancers - Stage I disease has a 5-year survival above 90%. Caught late, the picture is very different.
What makes colon cancer particularly tragic is that the early symptoms are easy to dismiss. A bit of blood in the stool that gets blamed on piles. A change in bowel habit blamed on stress or diet. Mild anaemia found on a routine blood test.
This guide walks through the early symptoms that should always be evaluated, who is at higher risk, and what a colonoscopy - the test that picks up early colon cancer - actually involves.
What is colon cancer?
Colon (colorectal) cancer is a malignant growth that starts in the large intestine or rectum. Almost all colorectal cancers begin as small benign growths called polyps. Over years - usually 5 to 10 - some polyps turn cancerous.
This long lead time is what makes colon cancer screenable. A colonoscopy can find polyps before they turn cancerous and remove them in the same sitting. This is why screening colonoscopy from age 45 to 50 is recommended in average-risk adults.
When colon cancer is caught at Stage I (confined to the inner layers of the bowel wall), surgical cure rates are above 90%. At Stage IV (spread to other organs), 5-year survival drops sharply. Every step earlier matters enormously.
Symptoms & when to seek help
- Blood in the stool - bright red or dark - even if intermittent
- Change in bowel habit lasting more than 4 weeks (looser, harder, or alternating)
- Unexplained weight loss with abdominal symptoms
- Iron-deficiency anaemia in adults, particularly men
- A persistent feeling of incomplete evacuation
- Abdominal cramping or bloating that is new and persistent
- Narrow or pencil-thin stools
Causes & risk factors
- Age over 45 to 50
- Family history of colorectal cancer or polyps in a first-degree relative
- Personal history of inflammatory bowel disease (ulcerative colitis, Crohn's)
- Diet high in processed and red meat, low in fibre
- Obesity, smoking and heavy alcohol use
- Type 2 diabetes
- Certain genetic syndromes (FAP, Lynch syndrome)
How it is diagnosed
- Outpatient consultation and digital rectal examination
- Colonoscopy - the single most important test; biopsies any suspicious area
- CT scan of the abdomen and chest for staging
- MRI of the pelvis for rectal cancers
- CEA blood test as a baseline tumour marker
- Multidisciplinary tumour board review before treatment is finalised
Treatment options
- Polyps and very early cancers can be removed during colonoscopy itself
- Localised colon cancer: laparoscopic colectomy with removal of the affected segment and lymph nodes
- Rectal cancer: often a combination of chemoradiation followed by surgery
- Adjuvant chemotherapy for higher-stage disease, planned with medical oncology
- Stage IV disease: combination chemotherapy, sometimes with surgery for liver or lung metastases
- Most modern colorectal cancer surgery is laparoscopic with equivalent long-term outcomes
Recovery & aftercare
- Day 0 to 1: surgery and early walking
- Day 2 to 4: gradual diet advancement, drains and catheters removed
- Day 5 to 7: discharge home in most cases
- Week 2 to 4: gradual return to office work
- Week 4 to 6: adjuvant chemotherapy planning if indicated
- Long term: surveillance colonoscopy and CEA monitoring on a structured schedule
Risks of delaying care
- Stage I cancer becoming Stage III over months
- Local invasion into bladder, ureter or pelvic structures
- Spread to liver, lungs or peritoneum (Stage IV)
- Bowel obstruction requiring emergency surgery
- Severe anaemia requiring blood transfusion
- Significantly worse 5-year survival with each stage of progression
Frequently asked questions
Reviewed by
Dr. Sanjay Yadagiri
Consultant - Minimal Access Surgery & Surgical Oncology
Over three decades of surgical experience. UK-trained, France-certified in laparoscopic and colorectal surgery, with a long association with the Indo-American Cancer Institute and Omega Hospitals, Hyderabad.
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