About rectal cancer

What is rectal cancer ?

Stage II Rectal Cancer

Stage II rectal cancer is a little more advanced. The tumor has penetrated all the way through the bowel wall and may have invaded other organs, like the bladder, uterus, or prostate gland. However, lymph nodes are not involved at this stage. Treatment includes:

  • Surgery to remove all the organs involved with the cancer (wide-resection)
  • Radiation with chemotherapy is given before surgery, or after surgery; chemotherapy alone is given for 4 months after surgery.

What are the symptoms for rectal cancer ?

Common symptoms include:

  • A change in your bowel habits, such as diarrhea, constipation or more-frequent bowel movements
  • Dark or red blood in stool
  • Mucus in stool
  • Narrow stool
  • Abdominal pain
  • Painful bowel movements
  • Iron deficiency anemia
  • A feeling that your bowel doesn't empty completely
  • Unexplained weight loss
  • Weakness or fatigue

When to see a doctor

Make an appointment with your doctor if you have symptoms suggesting rectal cancer, particularly blood in your stool or unexplained weight loss.

What are the causes for rectal cancer ?

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.

Inherited gene mutations that increase the risk of colon and rectal cancer

In some families, gene mutations passed from parents to children increase the risk of colorectal cancer. These mutations are involved in only a small percentage of rectal cancers. Some genes linked to rectal cancer increase an individual's risk of developing the disease, but they don't make it inevitable.

Two well-defined genetic colorectal cancer syndromes are:

  • Hereditary nonpolyposis colorectal cancer (HNPCC). HNPCC, also called Lynch syndrome, increases the risk of colon cancer and other cancers. People with HNPCC tend to develop colon cancer before age 50.
  • Familial adenomatous polyposis (FAP). FAP is a rare disorder that causes you to develop thousands of polyps in the lining of your colon and rectum. People with untreated FAP have a greatly increased risk of developing colon or rectal cancer before age 40.

FAP, HNPCC and other, rarer inherited colorectal cancer syndromes can be detected through genetic testing. If you're concerned about your family's history of colon cancer, talk to your doctor about whether your family history suggests you have a risk of these conditions.

What are the treatments for rectal cancer ?

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. Otherwise, it's not possible to take a margin of healthy tissue on all sides of the tumor — and clear or healthy margins reduce the risk that the cancer will return.

    After APR, it is no longer possible to pass stool through the anus. An end colostomy connects the end of the colon that was attached to the rectum before APR to a surgical opening (stoma) in the lower abdomen. Stool then passes into a removable pouch placed over the stoma.

  • Coloanal anastomosis
    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. The surgeon removes the entire rectum and enough of the surrounding tissue to achieve clear margins. Then the remaining end of the colon may be shaped into a pouch that is connected to the colon. Alternatively, the end of the colon may be connected directly to the anus.

  • 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. The surgeon removes the tumor and a margin of healthy tissue around it, leaving the lower part of the rectum. The end of the colon is then attached to the remaining section of the rectum.

  • Local excision
    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.

    Unlike the other procedures listed, local excision does not include lymph-node removal. Instead, the excised tissue is examined in a laboratory to make sure the tumor doesn't have features that suggest more-advanced cancer than expected. If any of these features are present, a standard operation may be necessary.

  • More-extensive surgery
    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.

Combination therapy

Standard treatment for stage II and stage III rectal cancers is typically a combination of chemotherapy and radiation (chemoradiotherapy) given before surgery (preoperatively). This approach is also an option for treating some stage I rectal cancers that have a high risk of recurring.

Benefits of preoperative chemoradiotherapy include:

  • Increased response to radiation because of chemotherapy's effect on cancer cells
  • Reduced tumor size
  • Lowered cancer stage in some cases
  • Better chance that surgery will leave the anal area intact (sphincter-sparing surgery)
  • Lower risk of cancer recurrence

The usual period between preoperative chemoradiotherapy and surgery is about six weeks. After surgery, most people also have additional chemotherapy to destroy any remaining cancer cells.

Stage IV rectal cancer

Some of the treatments used in stage II and III rectal cancers may also be appropriate for cancers in stage IV. By definition, though, stage IV rectal cancer has spread (metastasized) to a different part of the body, usually the liver.

In some cases, a metastatic tumor may appear in the liver when the primary tumor is still confined mainly to the rectum and nearby lymph nodes. If this happens, your doctor may recommend surgery to remove both the primary tumor and the liver tumor at once.

In other cases, the primary tumor may have spread to organs near the rectum, such as the uterus and ovaries, before liver metastasis appears. Complex surgery and reconstruction of pelvic structures may be possible in these cases as well.

Drugs for stage IV rectal cancer

Chemotherapy may extend life for people with stage IV rectal cancer, as may radiation therapy in some cases. Either treatment may be given after surgery, while chemotherapy is more commonly used before surgery. Chemotherapy or radiation may be used to relieve symptoms in cases where the cancer is too extensive for surgery.

People with stage IV rectal cancer may receive one of three newer FDA-approved drugs in addition to cancer chemotherapy. These drugs, called biologics, target cancer-cell traits that allow tumors to grow. The addition of a biologic drug to standard chemotherapy has been found to improve response to treatment in certain cases of colorectal cancer. Therapy that includes biologics is called targeted therapy.

The FDA-approved biologics used with chemotherapy in first line treatment of stage 4 colorectal cancer are:

  • Bevacizumab (Avastin)
  • Cetuximab (Erbitux)
  • Panitumumab (Vectibix)

Supportive (palliative) care

Palliative care is focused on providing relief from pain and other symptoms of a serious illness. Palliative care specialists work with you, your family and your other doctors to provide an extra layer of support that complements your ongoing care.

An example of palliative care might be surgery to relieve a blockage of the rectum in order to improve your symptoms.

Palliative care is provided by a team of doctors, nurses and other specially trained professionals. Palliative care teams aim to improve the quality of life for people with cancer and their families. This form of care is offered alongside curative or other treatments you may be receiving.

What are the risk factors for rectal cancer ?

The characteristics and lifestyle factors that increase your risk of rectal cancer are the same as those that increase your risk of colon cancer. They include:

  • Older age. The great majority of people diagnosed with colon and rectal cancer are older than 50. Colorectal cancer can occur in younger people, but it occurs much less frequently.
  • African-American descent. People of African ancestry born in the United States have a greater risk of colorectal cancer than do people of European ancestry.
  • A personal history of colorectal cancer or polyps. If you've already had rectal cancer, colon cancer or adenomatous polyps, you have a greater risk of colorectal cancer in the future.
  • Inflammatory bowel disease. Chronic inflammatory diseases of the colon and rectum, such as ulcerative colitis and Crohn's disease, increase your risk of colorectal cancer.
  • Inherited syndromes that increase colorectal cancer risk. Genetic syndromes passed through generations of your family can increase your risk of colorectal cancer. These syndromes include FAP and HNPCC.
  • Family history of colorectal cancer. You're more likely to develop colorectal cancer if you have a parent, sibling or child with the disease. If more than one family member has colon cancer or rectal cancer, your risk is even greater.
  • Dietary factors. Colorectal cancer may be associated with a diet low in vegetables and high in red meat, particularly when the meat is charred or well-done.
  • A sedentary lifestyle. If you're inactive, you're more likely to develop colorectal cancer. Getting regular physical activity may reduce your risk of colon cancer.
  • Diabetes. People with poorly controlled type 2 diabetes and insulin resistance may have an increased risk of colorectal cancer.
  • Obesity. People who are obese have an increased risk of colorectal cancer and an increased risk of dying of colon or rectal cancer when compared with people considered normal weight.
  • Smoking. People who smoke may have an increased risk of colon cancer.
  • Alcohol. Regularly drinking more than three alcoholic beverages a week may increase your risk of colorectal cancer.
  • Radiation therapy for previous cancer. Radiation therapy directed at the abdomen to treat previous cancers may increase the risk of colorectal cancer.

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