Better therapies needed
While ovarian cancer can't yet be prevented, its risk can be reduced. Taking oral contraceptives for at least five years cuts the danger in half for some types of the disease.
After ovarian cancer treatment and two relapses, Clare Matthews prizes each day and calls herself "blessed."
Tubal ligation also reduces risk, and diets high in lycopene (a component of tomato sauce) and the antioxidant carotene (found in yellow-orange fruits and vegetables) have been found to be protective.
Dr. Berkowitz says, "The greatest opportunity to have a dramatic impact on improving survival in ovarian cancer is by advancing our capacity to improve prevention as well as early detection." Still, Dr. Matulonis says, until more powerful preventives are identified and effective early-detection tests become available, "there is a need to continue developing better therapies once the disease is diagnosed."
Plaguing the treatment of this cancer is the tendency of ovarian tumor cells to become resistant to drugs that initially halted the disease. In one of the SPORE projects, Alan D'Andrea, MD, of DFCI, and Michael Seiden, MD, a medical oncologist at Massachusetts General Hospital, will use a new test to determine when ovarian tumor cells become resistant to platinum, one of the standard chemotherapy agents. The sooner they can find out, the sooner doctors can switch to other, usually experimental, drugs that may fight the tumor better. They're also testing compounds that might be able to make a resistant tumor susceptible again.
Individualized vaccines are another new weapon in the attack on ovarian cancer. These therapeutic vaccines, made from a patient's own tumor cells and modified with genes, have had some success in other forms of cancer, stimulating the immune system to stiffen its defenses against tumor cells.
Marcus Butler, MD, of the WCP and his colleagues have tested such a vaccine in Phase I trials in women with advanced ovarian cancer. Researchers implanted immune-stimulating genes into tumor cells so that, when the vaccine was injected into patients, their immune defenses would readily recognize and attack the remaining ovarian disease.
"We're seeing signs of immune responses in the skin," says Dr. Butler, but whether the defensive cells are fighting the residual tumor cells isn't yet clear. Two additional trials will open in late 2004 or early 2005, he says, to find out if the vaccine can reduce the chances of recurrence in women who are currently in remission.
SPORE funding will enable Donald Kufe, MD, of Dana-Farber, to test a vaccine that targets a protein, MUC-1, that is overproduced in some kinds of cancer, including ovarian. He said the first human tests could begin this year.
