Rectal Cancer is a form of colorectal cancer. It occurs when cancerous cells develop in the tissue of the rectum. The rectum is the last part of the large intestine and leads to the anus, which is the opening to the outside of the body. Body waste is stored in the rectum until it is eliminated from the body through the anus.
Although rectal cancer is a life-threatening disease, it is a highly curable form of cancer if found early. Therefore, regular check-ups and screenings are very important.
Although the exact cause of rectal cancer is unknown, certain risk factors have been identified that may increase a person's chance of developing the disease. These include:
- Age: The majority of rectal cancers are diagnosed in people aged 50 or older, although the disease affects all ages.
- Bowel disease: A history of colorectal cancer, intestinal polyps, and diseases such as chronic ulcerative colitis, Crohn's disease and inflammatory bowel disease increase a person's chance of developing rectal cancer.
- Diet and exercise: A diet high in fat, particularly from animal sources, and an inactive, sedentary lifestyle can increase a person's chance of developing rectal cancer.
- Ethnic background and race: Jews of Eastern European descent called, Ashkenazi Jews have a higher rate of rectal cancer. African-Americans and Hispanics have a higher death rate caused by rectal cancer, which may be caused by insufficient screenings, poor diet and lack of exercise.
- Family history/genetic factors: Specific genes have been identified that significantly increase a person's chance of having rectal cancer. People with a strong family history of colorectal cancer, as defined by cancer or polyps in a first-degree relative younger than 60 or two first-degree relatives of any age, are also at increased risk for developing rectal cancer.
- Smoking and alcohol: Research suggests that smokers and heavy drinkers have an increased chance of developing rectal cancer.
Common signs and symptoms of rectal cancer include:
- A change in bowel habits
- Diarrhea, constipation, or feeling that the bowel does not empty completely
- Blood, either bright red or very dark in the stool
- Stools that are narrower than usual
- General abdominal discomfort such as frequent gas pains, bloating, fullness or cramps
- Weight loss with no known reason
- Constant tiredness
Radiation therapy or chemotherapy may be given before surgery to shrink the tumor, make it easier to remove the cancer, and lessen problems with bowel control after surgery.
Surgery is the most common treatment for all stages of rectal cancer. The cancer is removed using one of the following types of surgery:
- Polypectomy -- If the cancer is found in a polyp (a small piece of bulging tissue), the polyp is often removed during a colonoscopy.
- Local excision -- If the cancer is found on the inside surface of the rectum and has not spread into the wall of the rectum, the cancer and a small amount of surrounding healthy tissue is removed.
- Resection -- If the cancer has spread into the wall of the rectum, the section of the rectum with cancer and nearby healthy tissue is removed. Sometimes the tissue between the rectum and the abdominal wall is also removed. The lymph nodes near the rectum are removed and checked under a microscope for signs of cancer.
- Pelvic exenteration -- If the cancer has spread to other organs near the rectum, the lower colon, rectum, and bladder are removed. In women, the cervix, vagina, ovaries, and nearby lymph nodes may be removed. In men, the prostate may be removed. Artificial openings (stoma) are made for urine and stool to flow from the body to a collection bag.
After the cancer is removed, the surgeon will either:
- sew the healthy parts of the rectum together, sew the remaining rectum to the colon, or sew the colon to the anus (anastomosis)
- make a stoma (an opening) from the rectum to the outside of the body for waste to pass through. This procedure is done if the cancer is too close to the anus and is called a colostomy. A bag is placed around the stoma to collect the waste. Sometimes the colostomy is needed only until the rectum has healed, and then it can be reversed. If the entire rectum is removed, however, the colostomy may be permanent.
Even if all the cancer that can be seen at the time of the operation is removed, some patients may be given radiation therapy or chemotherapy after surgery to kill any cancer cells that are left.