It is estimated that about 5% of Americans will develop colorectal cancer. Colon cancer is preventable and highly curable if detected in the early stages.
Who is at risk?
It is more likely to occur as people get older. More than 90% of people with colon cancer are diagnosed after age 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.
Is this disease avoidable?
Yes. Nearly all colon cancers develop from polyps. Detection and removal of these polyps by colonoscopy reduces the risk of getting colon 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 of colon cancer?
Many colon cancers cause no symptoms at all. The most common symptoms are changes in bowel habits like constipation, diarrhea, or blood in the stool. Abdominal pain and weight loss are usually late symptoms.
Evaluation: The stage is based on whether the tumor has invaded nearby tissues or lymph nodes, and whether the cancer has spread to other parts of the body. The exact stage is determined after surgery. Standard evaluations include colonoscopy with biopsy, CT scans, and specific blood tests.
Treatment: Surgery is almost always required for complete cure. With surgery, the colon cancer is removed along with some parts of the healthy colon on either side of the cancer and all the draining lymph nodes. Creation of a stoma is only needed in small number of patients. Depending on the features of the cancer a laparoscopic technique could also be used. Additional treatment with chemotherapy may be offered after surgery depending on the pathological evaluation. Unlike rectal cancer, radiation therapy is rarely use for colon cancer.
Follow-up care after treatment for colon cancer is important. The disease sometimes returns because undetected cancer cells remain somewhere in the body. You will have interval checks for recurrence of the cancer using blood and radiology tests.
(Simplified from Patient Eduction Brochures of The American Society of Colon and Rectal Surgeons)
Rectal cancer
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)
