Doctors in Manhattan have found a small, statistically significant link between women’s talcum-powder use and ovarian cancer, but the jury still is out on whether cosmetic products containing the ingredient actually can cause harm, these experts said.

Dr. Paolo Boffetta, associate director for cancer prevention at The Tisch Cancer Institute of Mount Sinai Hospital, reported his team’s finding in the European Journal of Cancer Prevention.

It was drawn from a meta-analysis that reassessed 24 previously published statistical analyses and also reexamined several so-called prospective studies that involved 302,000 patients with ovarian cancer.

Talcum powder’s main ingredient is highly purified talc, a mineral composed of the elements magnesium, silicon, oxygen and hydrogen, scientists said.

“Overall, it is about a 20 percent higher risk for women who say they used talc, compared to women who say they did not use it,” Boffetta said in an interview.

Consumer products giant Johnson & Johnson has faced a flurry of lawsuits related to Johnson’s baby powder and ovarian cancer. The product contains talc. Company officials have denied links between their powder and the disease.

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Three cases have won large jury awards — the most recent a $70 million verdict in October to a California woman who said she used baby powder for years before her ovarian cancer emerged .

Some cases have been thrown out by judges who ruled there wasn’t reliable evidence that talc causes ovarian cancer.

In a video statement last month, Tara Glasgow, the company’s vice president of baby research and development products, said the powder does not cause cancer. “We are guided by the science which supports the safety of Johnson’s baby powder,” she said in the video.

While Boffetta and his international team of scientists found an association, they have no evidence of a mechanism by which talc might cause the cancer.

“It would be premature to conclude that talc use causes ovarian cancer,” Boffetta said, magnifying one of many conundrums associated with this form of cancer.

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Most cases are what doctors call sporadic — that is, without a definable cause. There is no way to screen for ovarian cancer. Symptoms often are vague and initially can be mistaken as lesser, non-life-threatening conditions, resulting in many women being diagnosed at a late stage.

Moreover, the disease lacks the powerful advocacy and clout associated with other malignancies, which draw millions more in research dollars.

“The whole issue of talcum powder is seen as a possible agent. We don’t have strong links. Anything that can get in the peritoneal cavity can increase the risk,” said Dr. Eva Chalas, chief of gynecologic oncology and vice-chair of obstetrics and gynecology at Winthrop-University Hospital in Mineola. “We discourage patients from using anything that increases irritation or inflammation.”

Because there is no general form of screening for the cancer, Chalas said, taking precautions is important.

“Progress in gynecologic oncology has been very slow and that’s because there has been insufficient funding,” she said. “We have lost ground.”

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Boffetta, a former chief of environmental cancer epidemiology with the World Health Organization, said his talc research was not like studies of decades ago that found cigarettes to have a direct, carcinogenic impact on lung tissue.

As a meta-analysis, the investigation reexamined previous studies to seek a new conclusion. In this case, that was a small, statistically significant association between exposure to talc-containing products and serous carcinoma, the most common form of ovarian cancer.

Among cases examined in his analysis,, talc use could have dated back decades, Boffetta said. The studies also had imprecise data on duration and frequency of talc exposure, raising issues for further study.

More women die of ovarian cancer than any other reproductive malignancy and the majority of cases are sporadic, said Dr. Veena John, a medical oncologist at Northwell Health Cancer Institute in New Hyde Park who specializes in gynecologic cancers.

“It is one of the most lethal cancers,” she said.

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Ten percent to 15 percent of cases are caused by BRCA 1 or BRCA 2 gene mutations, which also are linked to breast cancer, she said. The cancer often is diagnosed late in its evolution, usually at stage 3 or 4.

Of talcum-powder exposure as a cause, John is not persuaded. “There is some evidence, but it is not well-established,” she said.

An estimated 22,000 new cases of ovarian cancer are diagnosed annually, and 14,000 women die each year of the disease, according to statistics from the American Cancer Society.