In a recent publication in the British Journal of Dermatology, researchers attempted to assess possible overdiagnosis by comparing subsequent melanoma incidence and biopsy rates among individuals subjected to skin screening with those who were not.

The study recruited 43,762 residents in Australia between the ages of 40 to 69 years with no previous history of melanoma, randomly selected from a population register in 2010.

At baseline, participants completed a comprehensive melanoma risk factor survey, and were questioned about skin examination by a doctor in the 3 years prior to baseline.

Researchers calculated incidence and relative risk of histologically confirmed melanoma (invasive and in situ) in years 2 to 7 of follow-up, acquired through linkage to the cancer registry. In secondary analyses, the researchers measured biopsy rates in years 2 to 6 of follow-up and utilized propensity score analysis to calculate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs).

Prior to baseline, 28,155 (73%) participants underwent skin screening. Researchers observed 967 first incident melanomas (381 invasive) during 197,191 person-years of follow-up.

Individuals screened had greater rates of melanoma (aHR, 1.29; 95% CI 1.02 to 1.63) and subsequent skin biopsies (aHR, 1.85; 95% CI 1.69 to 2.04) than unscreened participants. The greater risk linked with skin screening was evident for in situ melanoma (aHR, 1.45; 95% CI 1.09 to 1.92) but not invasive melanoma (aHR, 1.05; 95% CI 0.72 to 1.54).

In secondary analyses where screening was defined as having a skin biopsy in the first year after baseline, there was considerably heightened risks of melanoma and subsequent biopsies relative to those who did not have a biopsy.

The authors concluded, “Our analyses suggest that, after accounting for known risk factors, people undergoing physician-based screening for skin cancer have melanoma detection rates at least 29% higher than those not undergoing screening. While our primary analyses suggest that this effect is largely driven by increased detection of in situ melanomas, our secondary analyses observed similarly increased rates of invasive melanomas among screened versus unscreened participants.”

Source:

Whiteman DC, Olsen CM, MacGregor S, et al. The effect of screening on melanoma incidence and biopsy rates. Br J Dermatol. Published online May 9, 2022. doi:10.1111/bjd.21649