Primary Care-Based Melanoma Screening Linked to Higher Incidence of Thin Melanoma

Laura Ferris, MD, PhD

A new quality improvement study found that primary care-based melanoma screening was associated with increased detection of thin melanoma, which raised concerns about overdiagnosis.

Systematic skin cancer screening has been suggested to reduce melanoma mortality, yet no randomized clinical trials of melanoma screening have been performed.

This has raised concerns regarding overdiagnosis and increased detection of thin tumors that otherwise would not have been noticed that were unlikely to progress to a harmful cancer.

Investigators led by Laura Ferris, MD, PhD, Department of Dermatology at the University of Pittsburgh School of Medicine, compared thickness-specific incidence of melanoma in screened versus unscreened patients following primary care-based skin cancer screening.

Investigators invited primary care clinicians employed by the University of Pittsburgh Medical Center to participate in web-based, validated, skin cancer training that would inform them on how to perform fully body skin examination and recognize melanoma, keratinocyte carcinomas, lesions, and more.

Patients who were eligible for screening were those 35 years and older who visited UPMC for a primary care visit between January 1, 2014, and December 31, 2018. Patients who were diagnosed with melanoma prior to their first primary care visit or had a screening date during the study period were excluded.

Patients who were enrolled in the screen-eligible cohort were assigned screening status and a primary visit date.

From there, a text-based search of pathology reports in the UPMC system was utilized to confirm that only primary lesions were included.

A data analysis would be performed from January 2020 to January 2022, and main outcomes and measures included the thickness of melanomas diagnosed in screened and unscreened patients.

Investigators identified a total of 595,799 screen eligible patients. Among them, 144,851 (24.3%) were screened at least once.

Screened patients tended to be older, with a median age of 59, and more likely to be female (82,244; 56.8%) and non-Hispanic White (86.1%) compared to unscreened patients. Patients 65 years and older made up 32.9% of the screened and 28.4% of the unscreened cohort.

A total of 994 patients were diagnosed with melanoma in which thickness was determined during the study period. A total of 110 melanomas were diagnosed in the screened population within 60 days following the initial screen date.

After adjustments to age, sex, and race, investigators observed that screened patients were more likely to be diagnosed with situ (incidence, 30.4 vs 14.4; hazard ratio [HR], 2.6; 95% CI, 2.1-3.1) (P < .001) or thin invasive (≤1 mm) melanoma (incidence, 24.5 vs 16.1; HR, 1.8; 95% CI, 1.5-2.2) (P < .001) compared to unscreened patients.

Furthermore, screened patients were also more likely to be diagnosed with in situ (incidence, 26.7 vs 12.9; HR, 2.1; 95% CI, 1.7-2.6; P < .001) or thin invasive (≤1 mm) interval melanomas compared to unscreened patients.

Investigators suggested that future studies with longer follow-up were needed to determine the influence of screening on the incidence of thick melanoma and outcomes associated with high costs and poor outcomes.

“Real-world data can add to this to help to determine which patients, if any, can benefit from screening and the optimal screening strategies that maximize benefit and minimize cost and harms,” the team wrote. “Longer follow-up is needed to fully determine the association of screening with outcomes such as the incidence of thick melanoma, treatment cost and morbidity, distant metastasis, and death.”

The study, "Five-Year Outcomes of a Melanoma Screening Initiative in a Large Health Care System," was published online in JAMA Dermatology.