Patients at very high risk for melanoma, including those with a family history or with inherited pathogenic variants of genes that increase the risk, likely benefit from routine whole-body screening for melanoma and education about UV protection.
Those are key findings from the first prospective cohort study to quantify the benefit of screening in melanoma-prone families, which was published online April 2 in Cancer Epidemiology, Biomarkers & Prevention.
“Whole-body screening for melanoma is currently routine for individuals at high risk for melanoma, which includes people from melanoma-prone families (at least two relatives who have had melanoma) and those with inherited pathogenic gene variants of the CDKN2A or CDK4 genes, which increase risk for melanoma,” lead author Michael R. Sargen, MD, said in an interview. “In our study, we investigated whether screening and educational interventions, including education about the appearance of melanoma and strategies for protecting skin from ultraviolet damage, contributed to early diagnosis of melanoma in individuals from melanoma-prone families.”
Dr. Sargen, a dermatologist and clinical research fellow in the Division of Cancer Epidemiology and Genetics at the National Cancer Institute, Rockville, Md., and his colleagues evaluated data on 293 cases from the NCI Familial Melanoma Study, which was launched in 1976 to investigate inherited and environmental risk factors for the disease. Upon study enrollment and subsequent in-person visits, study participants received whole-body screening for melanoma, total body photographs with closeups of potentially problematic moles, education about the appearance of melanoma, and strategies for protecting their skin from UV damage. They were also counseled to follow up with their local dermatologist annually for whole-body screening exams.Of the 293 individuals who enrolled in the study between 1976 and 2014, 246 were diagnosed with melanoma before enrollment (the prestudy cohort) and 47 were diagnosed after enrollment (the prospective cohort). The researchers compared differences in melanoma thickness and tumor stage between participants in the prestudy and prospective cohorts, and compared tumor-thickness trends between participants in their study and cases in the general population using data from Surveillance, Epidemiology, and End Results (SEER) registries between 1973 and 2016. Because information on melanoma thickness was missing for 24% of melanoma cases in the NCI Familial Melanoma Study and 8.7% of melanoma cases found in the SEER registry, the researchers imputed the missing data.
After adjusting for gender and age, Dr. Sargen and his colleagues found that participants in the prospective cohort had significantly thinner melanomas, compared with those in the prestudy cohort (0.6 mm vs. 1.1 mm, respectively; P < .001). In addition, 83% of those in the prospective cohort were significantly more likely to be diagnosed at the early T1 stage, compared with 40% of those in the prestudy cohort (P < .001).
In their analysis, they also determined that after adjusting for gender and age, “all NCI family cases had systematically lower thickness than SEER cases during the study period.” The reductions in melanoma thickness and tumor stage, they concluded, “were not fully explained by calendar period effects of decreasing thickness in the general population and point to the potential benefit of skin cancer screening for patients with a family history of melanoma and those with pathogenic germline variants of melanoma-susceptibility genes.”