WEDNESDAY, March 6, 2024 -- There has been a considerable increase in the use of immunohistochemistry (IHC) staining for melanoma diagnosis, according to a study published online March 6 in JAMA Dermatology.

Kenechukwu Ojukwu, M.D., from the David Geffen School of Medicine at the University of California in Los Angeles, and colleagues examined trends in the use of IHC for examination of skin biopsies in incident melanoma cases diagnosed between January 2000 and December 2017 in a retrospective cross-sectional study. The analysis used the Surveillance Epidemiology, and End Results-Medicare linked database, which included data from 17 population-based registries, and focused on melanoma diagnosed in patients aged 65 years and older.

The final sample included 132,547 melanomas in 116,117 distinct patients. The researchers found that 33 percent of these diagnoses had accompanying IHC claims. Among these cases, 65 percent were diagnosed in men and 44, 38, and 18 percent were diagnosed in patients aged 65 to 74, 75 to 84, and 85 years and older, respectively. Overall, 11 percent of melanoma cases had claims for IHC at or near the time of diagnosis in 2000; this proportion increased annually and reached 51 percent in 2017. Increasing use of IHC was seen for all melanoma stages, including in situ melanoma. In all 17 registries, claims for ICH increased, but at different rates. Across registries, use of IHC for melanoma diagnosis varied from 39 to 68 percent in 2017.

"Given the extensive use of IHC in clinical practice, studies examining the resulting outcomes of IHC on different domains, such as symptom burden, quality of life, and mortality, are crucial," the authors write.