Study Concludes Most Melanoma Overdiagnoses Are In Situ

TOPLINE:

Melanoma in situ drives most cases of melanoma overdiagnoses, according to an analysis by Surveillance, Epidemiology, and End Results (SEER).

METHODOLOGY:

• The increase in melanoma diagnoses in the United States, while mortality has remained flat, has raised concerns about overdiagnosis of melanoma, cases that may not result in harm if left untreated. How much of the overdiagnoses can be attributed to melanoma in situ vs invasive melanoma is unknown.
• To address this question, researchers collected data from the SEER 9 registries database.
• They used DevCan software to calculate the cumulative lifetime risk of White American men and women being diagnosed with melanoma between 1975 and 2018, adjusting for changes in longevity and risk factors over the study period.
• The primary outcome was excess lifetime risk for melanoma diagnosis between 1976 and 2018, adjusted for year 2018 competing mortality and changes in risk factors.

TAKEAWAY:

• Researchers found that between 1975 and 2018, the adjusted lifetime risk of being diagnosed with melanoma in situ increased from 0.17% to 2.7% in White men and 0.08% to 2% in White women.
• An estimated 49.7% and 64.6% of melanomas diagnosed in White men and White women, respectively, were overdiagnosed in 2018.
• Among individuals diagnosed with melanoma in situ, 89.4% of White men and 85.4% of White women were likely overdiagnosed in 2018.

IN PRACTICE:

“A large proportion of overdiagnosed melanomas are in situ cancers, pointing to a potential area to focus for an intervention de-escalation of the intensity of treatment and survivorship care,” the authors wrote.

SOURCE:

Adewole S. Adamson, MD, of the Division of Dermatology at The University of Texas at Austin Dell Medical School, led the research. The study was published in BMJ Evidence-Based Medicine on January 19, 2024.

LIMITATIONS:

The analysis only involved White individuals. Other limitations include a high risk for selection bias and that the researchers assumed no melanoma diagnosis in 1975, which may not be the case.

DISCLOSURES:

Dr. Adamson disclosed that he is supported by the Robert Wood Johnson Foundation through The Harold Amos Medical Faculty Development Program. Coauthor Katy J.L. Bell, MBchB, PhD, of the University of Sydney, is supported by an Australian Government National Health and Medical Research Council Investigator Grant.

A version of this article first appeared on Medscape.com.