A change in your bowel habits, such as diarrhea, constipation or more-frequent bowel movements
- Dark or red blood in stool
- Mucus in stool
- Abdominal pain
- Painful bowel movements
- Iron deficiency anemia
- A feeling that your bowel doesn't empty completely
- Unexplained weight loss
- Weakness or fatigue
Rectal cancer occurs when healthy cells in the rectum develop errors in their DNA. In most cases, the cause of these errors is unknown.
Healthy cells grow and divide in an orderly way to keep your body functioning normally. But when a cell's DNA is damaged and becomes cancerous, cells continue to divide even when new cells aren't needed. As the cells accumulate, they form a tumor.
With time, the cancer cells can grow to invade and destroy normal tissue nearby. And cancerous cells can travel to other parts of the body.
More about Treatment
Rectal cancer often requires more than one treatment type (modality), an approach known as multimodal therapy. In general, the treatment modalities used in rectal cancer are the same ones used to treat many other types of cancer. They are:
Surgery to remove the tumor.
Chemotherapy, usually consisting of two or more drugs that target cancer cells. In people with rectal cancer, chemotherapy is often used along with radiation therapy, either before or after surgery.
Radiation therapy, which uses high-powered beams, such as X-rays, to kill cancer cells.
Your surgical options depend on a number of factors, including:
The stage and grade of the cancer, the location of the tumor in the rectum, the size of the tumor, your age, your general health, your medical history, your preferences after you learn about different procedures
Some of the procedures commonly used to treat rectal cancer are:
Abdominoperineal resection with end colostomy
Abdominoperineal resection (APR) offers the best chance of cure for rectal tumors located extremely close to the anal sphincter. With cancer in this location, the surgeon has to remove both the tumor and the sphincter.
This sphincter-sparing procedure may be an option for rectal cancer surgery if the tumor is at least .39 inch (1 centimeter) above the top of the anal sphincter.
Low anterior resection
This procedure, which also leaves the anus intact, may be performed when the tumor is located in the upper part of the rectum.
Local excision takes out the rectal tumor, along with a margin of healthy tissue and the section of rectal wall beneath the tumor. This technique is generally reserved for early, small stage 1 rectal cancers, after a biopsy shows that the tumor is unlikely to spread or recur.
People with rectal cancer associated with Crohn's disease, ulcerative colitis or a genetic predisposition to colorectal cancer typically need surgery that is more extensive than are the procedures described here. Chemotherapy is also needed before or after surgery.