Studies find benzoyl peroxide for acne has no increased risk for blood benzene, malignancy

Key takeaways:

• A watchdog organization previously reported high levels of the carcinogen benzene in benzoyl peroxide products.
• Two studies found no increase in blood benzene levels or malignancy in patients using these products for acne.

Patients with acne who used benzoyl peroxide products did not have a risk for malignancy or increased blood benzene levels, according to a pair of studies published in the Journal of the American Academy of Dermatology.

Valisure, a consumer watchdog organization, has previously raised concerns regarding the ability for products containing benzoyl peroxide (BPO) to develop high levels of benzene when handled or stored at higher temperatures. These studies were designed to evaluate how this could affect patients who rely on BPO products to treat acne.

“There have been concerns about the potential for BPO products to thermally decompose into benzene, a known carcinogen,” John Barbieri, MD, MBA, assistant professor at Harvard Medical School, director of the advanced acne therapeutics clinic at Brigham and Women’s Hospital and an author on both studies, told Healio. “However, it is uncertain whether this potential issue confers any clinically meaningful risks to those using BPO under routine conditions.”

Using data from the National Health and Nutrition examination Survey (NHANES), researchers of the first study evaluated blood benzene levels in a set of 14 adolescents and adults who had used BPO products and a group of 65 exact age-matched controls who did not report using BPO products.

Detectable blood benzene was found in five (36%) patients who had used benzol peroxide and 21 (31%) of those in the control group, with a mean level of benzene of 0.04 ng/mL in the exposed group and 0.05 ng/mL for the control group.

Logistic and linear regression models found no association between detectable blood benzene levels and BPO use (OR = 1.12; 95% CI, 0.46-2.74).

“This study found that those using BPO were not more likely to have detectable benzene levels in their blood and had the same average level of benzene among those with detectable benzene,” Barbieri said.

Additionally, a retrospective cohort study further explored the risk associated with BPO exposure and malignancy.

Using the ICD-10-CM codes for acne, patients who had been prescribed BPO were identified and selected, as well as a control comparator cohort of patients diagnosed with nevus or seborrheic keratosis (SK) who had not been exposed to BPO.

The risk for incident lymphoma, leukemia, hematologic malignancy and internal malignancy was assessed in both groups using Cox Proportional Hazards Models. A sensitivity analysis was conducted using a comparator cohort of patients with viral warts in order to include a younger population and increase sample size.

The study found no significant difference in risks for lymphoma (HR = 1; 95% CI, 0.68-1.47) leukemia (HR = 0.91; 95% CI, 0.51-1.65), any lymphoma or leukemia (HR = 1.04; 95% CI, 0.74-1.45) or internal malignancy (HR = 0.93; 95% CI, 0.79-1.08).

“These studies highlight that those who are using BPO products for acne do not appear to have increased levels of blood benzene or increased risk of hematologic malignancy or solid organ cancers,” Barbieri told Healio. “These data are reassuring for those who would like to use BPO for acne or other indications, especially as there are no direct substitutes for BPO in the management of acne. However, it still is important to store BPO products appropriately to minimize potential risk of benzene exposure.”

Valisure has called for all products containing BPO to be recalled and sales suspended; however, in a letter to the editor of the Journal of the American Academy of Dermatology, Barbieri stated that while exposure to carcinogens must be avoided, the absolute risk for BPO use should be considered.

“Since there is no direct alternative to BPO in the management of acne, avoiding its use will necessitate increased use of treatments such as oral antibiotics, spironolactone and isotretinoin, which each has its own risks to consider,” Barbieri wrote. “To minimize risk, we should educate patients and the public about the importance of appropriate storage of

BPO at room temperature or refrigerated and discard old products or those past its expiration date.”

References:

• Barbieri JS, et al. J Am Acad Dermatol. 2024;doi:10.1016/j.jaad.2024.05.093.
• Garate D, et al. J Am Acad Dermatol. 2024;doi:10.1016/j.jaad.2024.07.011.