by William Stanton, MD
Chemotherapy may be useful in up to 60 percent of patients with colorectal cancer seen by Scripps Cancer Center specialists.
The treatment is most effective earlier in the course of colorectal malignancy (Stages II and II) when given immediately before or after surgery, especially when the lymph nodes are involved.
International clinical trials with more than 4,000 patients demonstrate that when colon cancer involves lymph nodes, chemotherapy with standard agents reduces mortality by 30 percent. Clinicians at the Scripps Cancer Center are also testing whether adding the new drug Oxaloplatin enhances the ability of standard agents to save lives when used early in the course of the disease.
Chemotherapy also has an established role in improving the outcomes of patients receiving radiation therapy for rectal cancer. It works to enhance the effect of radiation locally, and it may also treat cancer that has spread beyond the pelvis where radiation is focused. Increasingly, chemotherapy and radiation are being used before rather than after surgery. In selected cases, pre-operative treatment can make it possible to avoid a colostomy.
When the colorectal cancer has spread to distant organs such as the liver or lung (Stage IV), chemotherapy may relieve symptoms and improve quality of life. In the past, a combination of two drugs has been used in patients with advanced colorectal cancer.
These drugs are 5FU and a vitamin known as folinic acid. The vitamin helps 5FU destroy cancer cells. Recently, irinotecan has become available and may be used together with 5FU and folinic acid for advanced disease.
There is some evidence that the addition of irinotecan to 5FU and folinic acid has better outcomes than when 5FU and folinic acid are used alone. More recently, a new agent called Capecitabine has been introduced for the treatment of advanced colon cancer. Capecitabine, which is given orally, may be especially useful for treating tumors that no longer respond to 5FU.
In the past several years, considerable progress has been made in making the administration of chemotherapy more comfortable and safe.
New drugs for nausea have greatly improved the quality of life of patients receiving cancer treatments. Medications to increase the red and white blood counts can also be used to treat anemia and reduce the risk of serious infection. New ways to administer chemotherapy have been developed that allow outpatient treatment for most patients, even those receiving prolonged intravenous infusions of medication.
One of the more exciting developments in oncology during the past year is the study of a new class of cancer treatment medicines called angiogenesis inhibitors. These drugs prevent the development of the blood vessels cancers need to survive and grow.
Oncologists at Scripps Cancer Center are currently testing SU5416, a new angiogenesis inhibitor, in the treatment of patients with advanced colon cancer.
The scientists and clinicians of the Scripps Cancer Center are working together to improve the outcomes in patients with colorectal cancer using these treatments.