Colon Cancer : Treating the Disease, Part 2

by Food and Drug Administration (FDA)

(Page 4 of 4)

If surgery reveals that the cancer has spread to the lymph nodes or other organs such as the liver, chemotherapy is usually prescribed. This was the case for cancer patient Vallarelli. Two days after her daughter's birthday, she awoke from surgery to learn that the tumor had invaded her uterus, and the doctors had performed a hysterectomy. It was devastating news for the 30-year-old, but nothing compared to what came next. Her sister gently informed her that the cancer had spread to her liver. Her chances for survival were not good, but, she says, her sister would not let her give up.

Just 44 days following her first surgery, Vallarelli returned to the operating room to have the left half of her liver removed. She spent two weeks in the hospital, weakened by the two surgeries, but encouraged by tests showing there was no cancer in the remaining part of her liver. Then she underwent chemotherapy, in which she was given a regimen of intravenous drugs.

The main approved drug for colorectal cancer treatment is 5-fluorouracil (5-FU), which has been in use for more than 30 years. This drug works by inhibiting an important enzyme in cancer cells. The standard chemotherapy programs have used a combination of 5-FU and leucovorin (folinic acid), a drug that enhances the action of 5-FU. This therapy is commonly given intravenously daily for five days, every four to five weeks, for six months.

In April 2000, FDA approved Camptosar (irinotecan) to be used in combination with 5-FU and leucovorin as a primary treatment for advanced colorectal cancer. Previously, Camptosar was used only in patients who failed to respond to the 5-FU and leucovorin combination. Recent studies have shown that the addition of Camptosar significantly delays tumor progression and improves the chances of survival. Camptosar's main side effect is diarrhea, which may be severe.

Vallarelli, whose chemotherapy took place before the approval of Camptosar as a primary treatment, says she experienced some weakness and diarrhea but was gratified that her hair loss was minimal.

An alternative method for the delivery of chemotherapy drugs is to use a pump and catheter. A small pump is implanted beneath the skin of the abdomen, and a catheter, a small, flexible tube, connects the pump to an artery that carries the drug directly to the tumor. After several weeks, the pump must be reloaded with chemotherapy by injecting more of the drug into the pump's reservoir. This method provides a continuous supply of the chemotherapy agent, though it may still cause side effects in the patient.

Many drugs are being studied that may improve colorectal cancer treatment, including oral drugs that are analogs of 5-FU or that increase 5-FU absorption from the gastrointestinal tract. This oral treatment results in prolonged exposure to 5-FU. "In advanced disease, it's been shown that prolonged exposure to 5-FU gives better results," says Martin Cohen, M.D., an FDA medical officer.

Cohen cites another class of drugs in the early stages of study: matrix metalloproteinase inhibitors. "The idea behind these drugs is that they would prevent cancer cells from spreading and thus would allow you to live with the cancer," he says. "It's too early for real data, but they're drawing much interest."

Living with cancer is something survivor Vallarelli knows plenty about. She has been cancer-free for four years, though she awaits the five-year mark when doctors will tell her she's likely to have beaten the disease. Meanwhile, she keeps a vigilant watch for signs of recurrence with periodic blood tests, CAT scans, and MRIs to screen for new growths.

"Going in for the testing every month is hard sometimes. It brings everything back to me. My strongest message to everyone is: Don't put off screening because of embarrassment. A little embarrassment or discomfort is a small price to pay to save your life."

Lifestyle Changes Could Save Your Life

In June 1999, the Harvard Center for Cancer Prevention released a report summarizing the impact of diet and lifestyle factors on colon cancer. The report came to a startling conclusion: Half of all colon cancers can be prevented through lifestyle changes and widespread screening.

Behaviors recommended by the Harvard report for lowering colon cancer risk include:

• Regular screening after age 50. This can reduce the risk of dying from colon cancer by at least 33 percent.
• Regular exercise. Physically active adults are half as likely to develop colon cancer as sedentary adults. The report recommends a daily workout of 30 minutes of vigorous exercise or one hour of brisk walking.
• Cut down on red meat. Eating one serving per day of red meat is associated with a 50 percent increase in risk.

The report also recommended maintaining a healthy weight, eating more vegetables, limiting alcohol intake, and not smoking.

About the Author

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