New Melanomas Difficult to Detect in Patients Treated With BRAF Inhibitors

Patients taking BRAF inhibitors are at an increased risk for developing new primary melanomas and nevi.

Patients taking a BRAF inhibitor are more susceptible to highly volatile melanocytic lesions that make the detection of new primary melanomas more difficult, according to results shared in a research letter published in JAMA: Dermatology.

Based on these findings, Sarah Yagerman, MD, of Memorial Sloan Kettering Skin Cancer Center, and colleagues recommended “total-body photography and short-term mole monitoring with dermoscopy as a method for monitoring atypical-pigmented lesions in the setting of highly volatile melanocytic changes in patients taking a BRAF inhibitor.”

According to background information in the letter, patients taking BRAF inhibitors are at an increased risk for developing new primary melanomas and nevi, and many of the neoplasms that develop are BRAF wild-type.

In their research, Yagerman and colleagues investigated the volatility of melanocytic lesions detected on overview photographs. They studied patients with baseline photographs taken within 1 year of BRAF inhibitor initiation therapy who also had follow-up photographs of their torso. They examined any new, growing, darkening or involuting melanocytic lesions.

The study included 13 men and 9 women. The patients' mean length of follow-up photography was 319 days, and patients had been on BRAF inhibitors for an average of 332 days. The mean number of combined new, growing, or darkening lesions was between 6.1 and 16.4. The mean number of involuting lesions was between 3.4 and 8.

Of the 42 melanocytic lesions identified, 83% were classified as benign and 17% were melanoma. No significant difference in time on a BRAF inhibitor was found between patients who had melanoma and those who did not.

The researchers wrote that their study was limited due to patient selection bias, as only those patients undergoing BRAF inhibitor therapy were assessed, and many of these patients had high-risk phenotype with many nevi.

“Further studies are needed to determine the extent of changes in all patients taking BRAF inhibitors,” the researchers wrote. “In addition, it remains to be seen if melanocytic changes are less dynamic in the setting of combined therapy with a MEK inhibitor, as was the case with squamous cell carcinomas.”