Colon Cancer: One of the Most Preventable Cancers

No — most rectal bleeding is caused by piles (haemorrhoids) or an anal fissure, not cancer. But blood in the stool should never simply be assumed to be piles, especially if it is new, persistent, or comes with a change in bowel habit or weight loss. A quick check can reassure you or catch something early.

The commonest signs are a lasting change in bowel habit (looser, more frequent, or constipation), blood in the stool or rectal bleeding, and tummy pain, cramping or bloating. Later there may be a feeling that the bowel does not empty fully, unexplained weight loss, and tiredness from low iron. Many of these overlap with piles or IBS, so a change that persists for more than a couple of weeks deserves a check. Early colon cancer can also cause no symptoms at all, which is why screening matters.

To a large extent, yes — more than most cancers. Because colon cancer usually grows slowly from polyps, a colonoscopy can find and remove polyps before they ever become cancer, preventing the disease. A healthy weight, more fibre, less red and processed meat, staying active, and not smoking also lower the risk.

Not necessarily — colon cancer is rising in adults under 50. Because younger people are not routinely screened and their symptoms are often mistaken for piles or an upset stomach, they are frequently diagnosed late. If you are young with persistent bowel symptoms, insist on getting them checked — being young is not a reason to wait.

For people at average risk, screening is usually advised from around age 45. You should start earlier — and be screened more often — if you have a family history of colon cancer or polyps, an inherited condition such as Lynch syndrome or FAP, or long-standing inflammatory bowel disease. Your doctor will help decide what is right for you, and a simple stool test (FIT) is a non-invasive first option.

A colonoscopy is a test in which a thin, flexible camera is passed gently through the back passage to look at the whole lining of the colon. It is usually done under sedation, so most people feel little or nothing and do not remember much of it. It is the most effective way to prevent colon cancer, because any polyps found can be removed during the same procedure — before they can ever become cancer. The bowel-cleansing prep the evening before is the least pleasant part, but it is short-lived.

A polyp is a small growth on the inner lining of the colon. Most polyps are harmless and are not cancer, but some types can slowly turn into cancer over several years if left. That is exactly why screening works so well: removing polyps during a colonoscopy stops them ever becoming cancer. Having a polyp removed usually means you will be advised when to have your next colonoscopy.

Often, yes — especially when found early. Colon cancer confined to the bowel is highly curable with surgery, and even cancers that have spread to lymph nodes are frequently cured with surgery and chemotherapy. Even stage IV colon cancer is very treatable, and some are still cured. Your outlook depends on the stage, which is why checking symptoms early and screening matter so much.

Colon cancer is staged from 0 to IV. Stage 0 is very early, contained in a polyp or the inner lining. Stages I–II have grown into the bowel wall but not the lymph nodes, and are usually treated with surgery. Stage III has spread to nearby lymph nodes and is treated with surgery followed by chemotherapy. Stage IV has spread to distant organs such as the liver or lungs and is treated with chemotherapy, targeted therapy or immunotherapy, and sometimes surgery. Early stages are highly curable.

The key test is a colonoscopy, which lets the doctor see the whole colon and take a biopsy to confirm the diagnosis (and remove polyps). A CT scan of the chest, abdomen and pelvis checks the extent, a blood marker called CEA helps with assessment and follow-up, and a PET-CT is used in selected cases. For advanced disease, the tumour is also tested for molecular features that guide treatment.

Both are “colorectal cancer,” but they start in different parts of the large bowel — the colon (the long part) versus the rectum (the last few inches). They are treated a little differently: radiation therapy is a key treatment for rectal cancer but is not usually part of colon cancer treatment, and a permanent stoma is much more a concern with low rectal cancer than with colon cancer. If your cancer is in the rectum, see our rectal cancer page.

For most colon cancers, surgery is the main, curative treatment — removing the affected part of the colon and nearby lymph nodes, often by keyhole (minimally invasive) surgery, with the bowel rejoined. Chemotherapy may follow to lower the chance of the cancer returning, particularly for stage III (and some stage II) disease. For advanced or stage IV disease, targeted therapy and immunotherapy — guided by molecular testing — are used, sometimes alongside surgery for limited spread.

Usually not for colon cancer — a permanent stoma is much more a concern with low rectal cancer. Most colon operations rejoin the bowel so it works normally, and when a stoma is needed it is often temporary. Your surgeon will explain exactly what to expect, and our stoma-care and rehabilitation team supports you if one is needed.

Not usually. Radiation therapy is a key treatment for rectal cancer, but colon cancer is treated mainly with surgery and, when needed, chemotherapy and molecular-guided targeted therapy or immunotherapy. This is one of the important differences between colon and rectal cancer. Our radiation oncologists lead treatment for rectal cancer and other sites.

For advanced colon cancer, the tumour is tested for molecular features. MSI/MMR status shows whether a cancer is likely to respond especially well to immunotherapy. KRAS and BRAF are genetic changes that guide which targeted therapies will or will not work. Testing for these helps personalise treatment to your specific cancer. For early colon cancer, surgery is usually curative and this testing is less central.

Most colon cancer is not inherited, but a minority is linked to a family history or an inherited condition such as Lynch syndrome or familial adenomatous polyposis (FAP). If colon or other bowel cancer runs in your family, genetic counselling can clarify your risk and, where relevant, guide earlier and more frequent screening for you and close relatives — which can find and remove polyps before cancer ever develops.

Cost depends on the stage and treatment — surgery, chemotherapy, and targeted therapy or immunotherapy for advanced disease — so it is best given as an indicative range after assessment. Eligible treatment may be covered under Aarogyasri or PMJAY at empanelled centres. Use the cost estimator on this page for an indicative figure, then request a callback for an accurate estimate.

Eligible colon cancer treatment may be largely covered under Aarogyasri and PMJAY at empanelled centres, and cost should not delay care. Our team helps check your eligibility and guides you on private insurance and EMI options, and will explain clearly what is covered so there are no surprises.

It can, which is why structured follow-up is an important part of care after treatment — usually with regular check-ups, CEA blood tests, scans and colonoscopies for a few years. Follow-up is designed to pick up any return early, when it is most treatable, and to check for new polyps. Chemotherapy after surgery, when advised, also lowers the chance of the cancer returning.