For Ovarian Cancer, More Than One Chemo Drug Available
July 24, 2001 -- More than 23,000 new cases of ovarian cancer were diagnosed last year, and most of those cancers were advanced. That means, even if the cancer responds to initial chemotherapy, the disease is likely to recur. When that happens, "having more than one effective chemotherapy drug [available] is important," a cancer specialist tells WebMD.
Alan Gordon, MD, a Dallas oncologist and author of a new study on ovarian cancer, tells WebMD that a new formulation of an old chemotherapy drug is proving to be an effective treatment option for the disease. The drug, called pegylated liposomal doxorubicin, or PLD, was as effective as topotecan, one of the most common drugs used to treat recurrent ovarian cancer. Gordon's study of more than 400 women with ovarian cancer is reported in the July 15 issue of Journal of Clinical Oncology.
Older formulations of doxorubicin were not effective for recurrent ovarian cancer. The difference here, says Gordon, is probably the slow-release design. With this new formulation, the drug, doxorubicin, is wrapped in a fat bubble, called a liposome, which allows the drug to remain in the blood stream longer and be released slowly to attack the tumor.
Another advantage with the pegylated, liposomal version is that it is given once every four weeks over a one hour-long infusion. Topotecan is infused over five days, usually Monday-Friday, every three weeks.
But the new formulation has some shortcomings. Cancer specialist Robert J. Morgan, MD, of the City of Hope National Cancer Center in Duarte, Calif., tells WebMD that even though pegylated, liposomal doxorubicin is easier to give to patients, it still falls short in treating recurrent ovarian cancer. That's because PLD -- like a handful of other chemotherapy drugs used to treat recurrent ovarian cancer -- is only effective in a small group of women.
"The response rates are just terrible," Morgan says. And that's true of both drugs studied by Gordon: Only 19% of women responded to the new doxorubicin formulation, compared with 17% of women treated with topotecan.
"That means that about 80% of the women are not responding" to treatment at all, says Morgan. That's a sobering fact for any cancer specialist. "That's why at City of Hope, we try to get these women into clinical trials because we are trying to get a better response rate," says Morgan.
Nonetheless, Maurie Markman, MD, director of the Cleveland Clinic's Taussig Cancer Center, tells WebMD that the new doxorubicin is an "acceptable option for treating recurrent ovarian cancer." It is important, he says, "that we have another treatment choice" to consider.
Painful side effects are another problem with the new doxorubicin. One side effect, called PPE, or palmar-plantar erythrodysesthesia, causes a great deal of pain in the hands and feet. Another painful side effect, called stomatitis, affects the mouth, adds Morgan.
Markman acknowledges that both PLD and topotecan are very toxic with significant, but different, side effects. Gordon explains that topotecan attacks blood cells so it is likely to cause anemia, while PLD causes mouth sores, rashes, and PPE.
As a result, many women will decide which drug to take based on which side effect they consider more bearable. "For example, I have a patient who is an organist at a church. She tells me that she doesn't want a chemotherapy drug that is going to affect her hands, her feet, or her mouth, so PLD is not for her," Gordon says.