The rectum is the last portion of the large intestine. Large bowel cancer is the 3rd most common cancer in both men and women. Colorectal cancer is curable if detected in early stages.

Who is at risk?

Rectal cancer tends to occur in older people. About 90% of people with this disease are older than 50. Other risk factors include a family (close relatives) history of colorectal cancer, personal history of inflammatory bowel disease, presence of colon polyps or cancers of other organs.

Can it be prevented?

Yes. Nearly all rectal cancers develop from polyps. Detection and removal of these polyps by colonoscopy reduces the risk of getting rectal cancer. Screening typically starts at age 50 in patients with average risk, or at younger ages in patients at higher risks for colon cancer. A high fiber (whole grains, fruits, vegetables, nuts), low fat diet is the only dietary measure that might help prevent colon cancer.

What are the manifestations?

Many rectal cancers cause no symptoms at all. The most common symptoms are changes in bowel habits such as constipation or diarrhea, narrowing in the stools, or blood in the stool. Hemorrhoids don’t cause rectal cancer but cause similar symptoms. Anyone should with these manifestations should see a doctor for appropriate treatment.

How is the diagnosis made?

Physical exam and medical history. Digital rectal exam. Colonoscopy and biopsy.

How is the outcome determined?

The stage of the cancer. Location in the rectum. Whether the bowel is blocked or not. Invasion of the nearby tissues. The patient’s general health.

Staging of the rectal cancer: CT scan and/or PET scan and CEA level for distant staging. For local staging, MRI to determine if the tumor has spread through the wall of the rectum or EUS evaluation.

Treatment: For complete cure, surgery is the mainstay of treatment. With surgery, the cancer and lymph nodes are removed together with portions of healthy bowel. Creation of a stoma depends on the rectal cancer. Laparoscopy could be used for surgery. Additional treatment with preoperative or postoperative chemotherapy or radiotherapy depends on the stage of the disease.

(Simplified from Patient Eduction Brochures of The American Society of Colon and Rectal Surgeons)