Tremendous advances have been made in the treatment of colorectal cancer, offering more patients the opportunity to live longer.

A quick glance at the numbers

Colorectal cancer (CRC) is a relatively common cancer that affects about 150,000 patients in the U.S. each year. It is the third most commonly diagnosed cancer in the U.S. and the second leading cause of cancer death. The general population has about a 2 percent risk of developing colorectal cancer by the age of 70 years old.

Over the last twenty years, the incidence has decreased significantly which could be attributed to increased screening, improved surgical techniques, early diagnosis and chemotherapy improvements.

Survival rates have also improved. During the mid 70s, about 50 percent of CRC patients survived their disease by at least five years. As of 2004, about 65 percent of CRC patients survive their disease by at least five years.

Certain risk factors have been associated with CRC and they include:

• Patients older than 50
• Prior history of colon cancer or colon polyps
• Family history of colon cancer
• Certain gastrointestinal disease such as ulcerative colitis or Crohn’s disease
• High-fat, low-fiber diets

The Stages of CRC

Like many cancers, CRC advances through stages.

If the CRC is caught and treated at an early stage, often no further treatment is recommended.

Stage II disease is still considered a relatively early stage although the risk of recurrence is higher than Stage I due to risk factors.  The use of chemotherapy at this stage is controversial among cancer doctors.  Some Stage II patients receive chemotherapy to decrease their recurrence rate. If the risk of recurrence is relatively small, there may still be some benefit to chemotherapy, but the potential benefit may not be worth the ill side effects, cost, and effort.

Stage III CRC is more advanced and involves cancer that has spread to the lymph nodes around the colon, but has not invaded the organs distant from the colon. Chemotherapy has shown definite benefit by decreasing the recurrence rate and improving the survival rate of patients with resected stage III CRC. New drug therapies, such as oxaliplatin, that when added to the older drugs such as 5-FU and leucovorin, improve survival rates.

Stage IV is the most advanced stage and is defined as having spread to distant organs. Surgery is usually done to remove the primary colon cancer and may be done to remove isolated cancer deposits from the liver. Chemotherapy can significantly prolong survival in stage IV CRC and significant advances have been made in the last several years.

Not only have new chemotherapy agents become available that add to the benefit of older agents, but other agents have been developed that are not technically chemotherapy, but still have anti-cancer activity.

Some of the newer agents target specific biological processes that are needed by cancer cells to grow. Therefore, the agents are often referred to as “targeted agents”. These targeted agents may affect normal cells, but do so to a much lesser degree than standard chemotherapy.

In general, these targeted agents are well tolerated and when added to standard chemotherapy, may significantly increase the benefit without increasing the ill side effects.

Sadly, survival in patients with stage IV CRC is still relatively short, even with the use of the newer agents. The present day standard care chemotherapy for metastatic, Stage IV CRC results in the usual survival of about 22 months, which is nearly double the usual survival of 12 months from the standard chemotherapy of six years ago.

Catching CRC Early

The general population should start screening for CRC at about age 50, but only about 40% of the population get this potentially life-saving process. Screening may include the insertion of a flexible scope into the colon to look for abnormalities. This is called a colonoscopy and patients are usually sedated during the procedure. Other screening tests may include tests for blood in the stool, or an X-ray procedure called a Barium enema.

Colon cancers probably start as small noncancerous, or benign, growths called polyps. Over the course of several years, these may grow and, for various reasons, may slowly become more and more abnormal until they eventually become cancerous. Luckily, most polyps are benign. Screening allows doctor to detect and remove polyps before they become cancerous and before any problems have developed. If a relatively small cancer has already developed, a colonoscopy may allow the doctor to detect and remove the cancer, using the scope, before it has advanced.

If a cancer has become too advanced to be removed during the colonoscopy, the cancer will require surgical resection. Obviously, the earlier the cancer is detected and removed, the better the outlook for the patient and the easier the cancer is to treat.

Surgery remains the primary treatment of CRC.  The more advanced a cancer is at the time of surgical resection, the more likely it is that microscopic deposits of cancer cells have already spread elsewhere in the body.

These deposits may grow and appear later as recurrent disease in the tissues near the original surgical site or in distant tissues, having traveled through the blood stream or the lymphatic system.

David Sullivan, M.D. - David Sullivan, M.D. joined the Family Cancer Center in 2005.  He graduated from the University of Mississippi medical school and completed his residency in Internal Medicine at the University of Tennessee.  When not working, he enjoys spending time with his family.