Colorectal Cancer

Colorectal cancer is cancer of the large intestine (colon) or rectum. It is rising in India along with urbanisation, sedentary lifestyles and diet changes. Caught early, it is largely curable; caught late, much less so. Screening saves lives.

Symptoms

• Blood in stool — bright red or darker; any age.
• Change in bowel habit (new constipation or diarrhoea, pencil-thin stool) lasting more than 2-3 weeks.
• Feeling bowel hasn't emptied fully.
• Unexplained weight loss.
• Iron-deficiency anaemia in a man or post-menopausal woman — colorectal cancer is always on the list.
• Persistent abdominal discomfort, bloating, cramps.
• Fatigue.
• Obstruction symptoms (vomiting, absolute constipation) — late sign.

Risk factors

• Age over 50 (but rising in younger adults).
• Family history; inherited syndromes (Lynch, familial polyposis).
• Inflammatory bowel disease (long-standing UC or Crohn's).
• Previous colon polyps.
• Obesity, sedentary lifestyle, diabetes.
• Diet low in fibre and high in red/processed meat.
• Heavy alcohol, smoking.
• Radiation to the pelvis.

Screening — the biggest lifesaver

• From age 45-50, or earlier with family/genetic risk or IBD.
• Colonoscopy every 10 years — gold standard; detects and removes polyps, preventing cancer.
• Stool tests (FIT test) every 1-2 years — simpler, needs follow-up if positive.
• Screen until at least age 75.

Diagnosis and staging

Colonoscopy with biopsy confirms diagnosis. CT abdomen/chest, MRI pelvis (for rectal cancer) are used for staging. Tumour molecular tests guide chemotherapy and targeted options.

Treatment

• Surgery is the main curative treatment for early/localised cancers.
• Adjuvant chemotherapy for certain stages.
• Rectal cancer often needs preoperative chemoradiation + surgery.
• Advanced / metastatic disease — chemotherapy, targeted therapy, sometimes surgery for liver-only spread (a distinct curative approach).
• Lynch syndrome and other inherited cancers need family testing and lifelong surveillance.

Prevention

• Diet rich in whole grains, dals, vegetables, fruits; less red/processed meat.
• Daily movement; healthy weight.
• Moderate or no alcohol.
• Don't smoke.
• Ask about screening at your annual check — a polyp removed today is a cancer that never happens.