Two .
Earlier this year, controversy erupted after an independent lab Valisure petitioned the US Food and Drug Administration (FDA) to recall acne products with BP because it found extremely high levels of the carcinogen benzene. In the research, the lab directors contended that the products can form over 800 times the “conditionally restricted” FDA concentration limit of 2 parts per million (ppm) of benzene, with both prescription and over-the-counter (OTC) products affected. The issue, according to the lab’s report, is one of degradation, not contamination; BP can decompose into benzene. Exposures to benzene have been linked with a higher risk for leukemia and other blood cancers.
Kittisak Kaewchalun/iStock/Getty Images
(“Conditionally restricted” means that the maximum of 2 ppm only applies to a drug product in which the use of benzene is unavoidable in order to produce a drug product with a significant therapeutic advance, according to FDA guidance.)
Critics of the report questioned the method used to test the products, calling for more “real-world” use data, and said the temperature used may not be what is expected with everyday use.
Now, both new studies are reassuring about the safety of the products, John Barbieri, MD, MBA, assistant professor of dermatology at Harvard Medical School and director of the Advanced Acne Therapeutics Clinic at Brigham and Women’s Hospital, Boston, said in a telephone interview. He was a coauthor of both studies. A leading dermatologist not involved in the new research reviewed the findings and agreed.
Brigham and Women's Hospital
Dr. John Barbieri
One study using data from the National Health and Nutrition Examination Survey compared blood levels of benzene between 14 people who had used BP products and 65 people without a history of BP product use, finding no difference between the groups .
The other, much larger study analyzed electronic health records of more than 27,000 patients with acne using BP products, comparing them with more than 27,000 controls who did not use the products. The patients were followed for 10 years after the use of BP products began, and no increased risk for cancer, either blood cancers or solid tumors, was found.
The studies were recently published in the Journal of the American Academy of Dermatology.
“Both studies are well done,” said Henry W. Lim, MD, former chair of the Department of Dermatology and senior vice president for academic affairs at Henry Ford Health, Detroit. Dr. Lim, a former president of the American Academy of Dermatology, reviewed the results of both studies.
Dr. Lim
Dr. Henry W. Lim
“These studies indicate that [a] report of detection of benzene in [BP] products exposed to high temperature does not have any relevant clinical significance, both in terms of blood levels and in terms of internal cancer,” Dr. Lim said. “This is consistent with the clinical experience of practicing dermatologists; no internal side effects have been observed in patients using [BP products].”