An ongoing study of women in nine countries shows that the injectable contraceptive Depo-Provera probably does not cause breast or cervical cancer, a spokesman for the World Health Organization, which is conducting the study, said yesterday.
WHO representatives, who presented the details of their study to a special Public Board of Inquiry, refused to elaborate on their findings to reporters.
The Upjohn Co., which makes Depo-Provera, is asking the government to allow its sale in this country. The contraceptive has been taken by 10 million women in 80 countries, but the Food and Drug Administration banned its use as a contraceptive in the United States, chiefly because of studies in which beagles and monkeys given the drug got cancer.
Spokesmen for both the FDA and Upjohn say that the WHO study is "appropriate" and "well-designed." However, despite the preliminary findings, there still is no agreement on whether Depo-Provera is dangerous.
An FDA consultant who has seen the details of the WHO data has told the FDA that, following a quick analysis, the WHO study "still is not useful. That doesn't mean it won't be useful in the future."
He said WHO must collect more data over a longer period and analyze more thoroughly the data it already has collected.
Upjohn spokesmen said that the study is important to their case.
The company dismisses its own animal studies, which showed that the drug caused cancer, because the animals were not "good models" for whether Depo-Provera can cause cancer in humans, spokesmen said. They noted that beagles are extremely susceptible to spontaneous breast tumors, and that the cancers in the monkeys arose in a type of cell not found in humans.
According to Upjohn, approval of Depo-Provera for American women must rest chiefly on the WHO study and on the fact that the medical literature fails to show an unusually high occurrence of cancer in women who have taken the drug.
The FDA defends its ban of Depo-Provera. Robert N. Temple, acting director of FDA's Office of New Drug Evaluations, told the hearing that the animal studies show that Depo-Provera causes cancer, that little is known about the drug's effect on humans and that several other contraceptives are available.
Until now, there have been no controlled, scientifically acceptable studies tracking women who have taken Depo-Provera over several years.