New Weapons Against Colon Cancer

Treatments for this killer have taken a big step forward

Elaine Caldwell has a physical exam every year but has never been screened for colon cancer. "They give you that little home-testing kit as you're walking out the door like it's no big deal. I never get around to it," says the 62-year-old real estate agent in Houston. Unfortunately, Caldwell is not alone. Unlike tests for breast and prostate cancer, colon-cancer screenings often get shrugged off--with fatal results. The American Cancer Society says 50,000 people will die of the cancer this year, despite a 92% survival rate when the disease is detected early.

Fortunately, the fight against colon cancer is gaining on several fronts. For the first time in 40 years, new drugs promise to improve survival rates as well as patients' quality of life (table). A wider range of screening options is also helping people detect the disease. And prevention is coming to the forefront of research, including initial studies on the effectiveness of aspirin, nonsteroidal anti-inflammatory drugs, and Cox-2 drugs used for arthritis in curbing the disease.

Among drugs, the standard chemotherapy treatment, fluorouracil (known as 5-FU), suddenly has a slew of potential partners. The Food & Drug Administration approved Camptosar by Pharmacia & Upjohn last October as a second-line treatment to be given when 5-FU fails. Studies show that Camptosar, which, like 5-FU, is administered intravenously, prolongs lives as well allays such symptoms as fatigue, abdominal pain, and constipation, by curbing an enzyme that tumor cells need to replicate. Camptosar is causing excitement for another reason: It may work in tandem with 5-FU, which interferes with tumors' metabolism. Subjects treated with the combination "had a more than 50% response rate, compared with 29% of those who received the usual 5-FU preparation," says Dr. Leonard Saltz of Memorial Sloan-Kettering Cancer Center in New York, who led a nearly two-year study involving 669 patients. His findings indicate that this combination chemotherapy may soon become a first-line treatment.

SIDE EFFECTS. Another promising compound is oxaliplatin, a platinum-based drug that a venture by Eli Lilly and Sanofi Pharmaceuticals plans to submit for FDA approval this year. The intravenously administered drug, which causes tumor cells to self-destruct, also works well in combination with 5-FU. Like most chemotherapies, oxaliplatin can harm normal cells, causing side effects such as a weakened immune system and nausea.

Patients can take heart as well from the prospect of dispensing with intravenous (IV) devices, at least for some of their treatment. In the pipeline are oral 5-FU formulations. Hoffman LaRoche is seeking to expand the use of breast cancer drug Xeloda to colon cancer. Bristol-Myers Squibb's oral 5-FU, Orzel, is also under FDA consideration. Both, studies show, are as effective as the intravenous versions.

Despite the drug advances, early detection remains your best chance for survival. With this disease, early diagnosis is rare without regular screenings because symptoms often appear only when the cancer is at an advanced stage. The American Cancer Society, National Cancer Institute, and Centers for Disease Control recommend that anyone over 50 be tested regularly and will mount a campaign next year to raise public awareness.

Doctors disagree about which exam is best and most cost-effective, however. Insurers also differ on which they cover. "It's up to each individual," says Dr. Gabriel Feldman of the American Cancer Society. If you have a family history of the cancer, your doctor may devise a regimen that calls for frequent exams.

The simplest and least invasive method is an annual fecal occult test, which costs $10 and can be done at home. A sigmoidoscopy ($150), in which a doctor uses a periscope-like device to check the lower colon, needs to be done only every five years. Another alternative is a barium enema, a $300 procedure that needs to be done only once a decade. The colon is filled with barium so that any growths will be easier to see in an X-ray. Like a barium enema, a colonoscopy can be done once every 10 years. In this exam, which calls for sedation, a doctor explores the colon with a camera that also has retractable blades. Any polyp found can be removed immediately--as is not the case with other methods. Costs start at $600 to $800 but can go as high as $1,400.

Screening soon may become less invasive, thanks to "virtual colonoscopy," which uses computed tomography (CT). In the technique developed at Wake Forest University Baptist Medical Center in Winston-Salem, N.C., a CT scan of the pelvis and abdomen is transformed into a 3-D view of the inside of the colon and rectum. Hundreds of hospitals are trying out the procedure, which costs around $1,400 and is not yet covered by insurance as a screening tool. "It takes 10 minutes and has an accuracy rate of 90% or better," says Wake Forest radiologist David Vining, who holds a patent on the process. In any case, the first step--taking the test--is still up to you. It takes little effort to keep yourself from becoming a colon cancer statistic.

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