Surgery and radiation successfully treated Joe Urban's prostate cancer. Soon, thanks to new understanding of the biology of cancer and how genes can identify who is most at risk, those traditional treatments may be combined with new drugs to make cancer as controllable a disease as high blood pressure or diabetes.
"It's a whole new ballgame," says oncologist Waun Ki Hong of the University of Texas M.D. Anderson Cancer Center. Traditionally, doctors have had to wait until a person gets cancer -- and may even have metastasized -- before being able to give diagnosis and treatment. Hong says that's like "sending a fire truck when the building is almost a bonfire."
Hong is a pioneer in chemoprevention, the use of drugs to slow and even halt the growth of cancer cells. Soon, he says, "we'll be able to identify the individual getting cancer, use imaging to pinpoint the area and the potential bad actors and target them" -- leaving healthy cells relatively unscathed.
Tamoxifen, used to prevent a recurrence of breast cancer, is a forerunner of this therapy, as is Celebrex, the arthritis drug recently approved to reduce colorectal polyps, which can lead to colon cancer. M.D. Anderson is studying the use of synthetic vitamin A on cancer of the mouth and larnyx, as well as Celebrex on lung cancer.
"The hope is our weapons against cancer will be more precise," says Susan Hellmann, an oncologist at Genentech, which developed the breast cancer drug herceptin.
Eventually, experts say, cancer therapy will be tailored specifically to an individual's needs. Treatments will be injections or pills, not the harder-to-take IVs or extra hospital time required by radiation and chemotherapy.
The deadliest cancers are those that spread fastest, such as pancreatic and liver cancers. Jim Wright, CEO of Lorus Therapeutics, says the company is in Phase 3 of clinical trials -- the last phase before it goes to the Food and Drug Administration for approval -- of an immunotherapeutic drug, Virulizin, that activates the body's natural immune response to combat growth of pancreatic cancer.
"We haven't given up the hope that we'll eventually have a cure," Wright says. "But there is a new paradigm. It's becoming clearer that cancer is a very complex disease; we'll have to approach it as a maintenance disease, like diabetes and insulin."
Meanwhile, some drugs have shown promise in halting the spread of cancer when used in combination with surgery and chemotherapy. They include:
-- Iressa (now before the FDA), which targets lung cancer, the No. 1 cancer killer of American men and women. It's taken once daily in tablet form.
-- Herceptin, which targets production of the HER2 protein, which is oversuppressed in about 15% of women with breast cancer. Its use in late-stage cancer patients increased life expectancy 25%.
-- Gleevec, used in late-stage cancer of the head, neck, colon and lung, as well as leukemia.
-- Thalidomide, the sedative that caused birth defects in the 1950s, is now used for a bone marrow cancer called multiple myeloma to halt angiogenesis (creation of blood vessels to feed a growing tumor). Avastin, an injection, is in Phase 3 studies for halting angiogenesis in breast, colon and lung cancers.
Another promising therapy is using a vaccine to boost the immune system's natural ability to fight disease. Unlike vaccines for childhood diseases, one shot won't prevent cancer for a lifetime, although researchers won't rule that out as a possibility someday. Instead, drugs under study are administered after a serious bout with cancer to prevent recurrence. Donald Morton, medical director at John Wayne Cancer Institute in Santa Monica, Calif., has worked for 40 years on a vaccine for melanoma, a skin cancer. Canvaxin is now in Phase 3 trials.
Some cancers share properties that could allow one vaccine to prevent recurrence in several types of the disease. For instance, the melanoma vaccine shares antigen targets associated with colon cancers. "It may be," Morton says, "there's enough cross-reactivity that a universal cancer vaccine could be developed."
