Five years after diagnosis, 91.5% of people with early-stage bowel cancer are still alive, according to figures from the National Cancer Institute. For stage 4, the number is 16.2%.
Those two figures, passed along in a patient guide from Booking Health, frame the whole question of prognosis. Survival depends first on the stage at diagnosis: how far the tumor has grown into the bowel wall, and whether it has reached lymph nodes or organs such as the lungs, liver or bones.
Stage by stage
The same National Cancer Institute data give five-year survival of 87% for stage 2A and 63% for stage 2B. In stage 3, it is 89% for 3A, 69% for 3B and 53% for 3C. The guide ties the drop at 3C to the number of lymph nodes involved, which makes it harder to remove every site of cancer.
At stage 4 the disease has spread to distant parts of the body, usually the liver first. The number and location of those metastases weigh heavily on the outlook. Booking Health says a short survival time is often linked to late diagnosis, and that the picture is personal: patients under 60 do better, as do those with no other serious illness, particularly of the liver, kidneys or heart, and those whose tumor responds to chemotherapy.
Why detection matters
Bowel cancer can start in any part of the large bowel, including the colon and rectum, and it often grows out of a benign polyp. The guide cites research that 15% to 40% of colon cancers arise from polyps over two to five years.
Early signs include constipation, diarrhea or narrow stools. Blood in the stool, weakness and weight loss come later. In advanced disease a blocked bowel can cause sharp abdominal pain and need emergency treatment.
Treatment differs by location. Colon cancer usually begins with surgery, followed by chemotherapy in some cases. Locally advanced rectal cancer usually starts with chemoradiotherapy before the operation.
Survival rates describe groups of patients, not individuals, and they say little about how many years any one person has left. Consult your doctor for medical advice.
