Mind the Gap: Impact of New Labels on Public Perceptions and Calculated Risk of Adverse Outcomes after a Melanoma In Situ Diagnosis-A Secondary Analysis of an Online Randomized Experiment.

BACKGROUND: Alternative diagnostic labels for melanoma in situ may better reflect its lower risk (15-y survival of 98%) compared with invasive melanoma (10-y survival ranging from 98% for American Joint Committee on Cancer stage IA to 19% for stage IV). DESIGN: Secondary analysis of an online randomized experiment in Australian adults without melanoma. Participants were randomized to a hypothetical diagnosis of "melanoma in situ (MIS)" (control), "low-risk melanocytic neoplasm," or "low-risk melanocytic neoplasm, in situ" and completed a survey. OUTCOMES: Perceived risk measures were future invasive melanoma and mortality risk (0%-100%), comparative risk, affective risk, and vulnerability (7-point Likert scales). Calculated risk measures were lifetime invasive melanoma risk (from participants' risk factors) and melanoma mortality probability (Australian sex-/age-specific mortality rates). ANALYSIS: An intention-to-treat analysis across randomized groups was performed, unadjusted and adjusted for covariates (linear regression models). RESULTS: In total, 1,668 adults were recruited. Compared with MIS, perceived melanoma mortality risk was lower for low-risk melanocytic neoplasm (-10.4%, 95% confidence interval [CI]: -13.1% to -7.63%, P < 0.001) and for low-risk melanocytic neoplasm, in situ (-7.4%, 95% CI: -10.2% to -4.6%, P < 0.001). Similar patterns were observed for perceived risk of invasive melanoma; comparative, affective risk; and vulnerability. Participants in all groups substantially overestimated their lifetime risk of invasive melanoma (by 48.7%) and of dying from melanoma (by 32.0%) compared with the calculated risk; overestimation was lower in alternative label groups. CONCLUSIONS: Diagnostic labels without the word "melanoma" reduced risk overestimation, supporting MIS relabeling to mitigate overdiagnosis harm by reflecting its largely indolent nature. TRIAL REGISTRATION: ANZCTR: 386943HighlightsAlternative diagnostic labels for melanoma in situ that do not include the word "melanoma" significantly decreased perceived risk compared with melanoma in situ.Participants substantially overestimated their risk; alternative labels reduced this overestimation of perceived risk compared with calculated risk.A new label for melanoma in situ may better communicate the lower risk of adverse outcomes for this lesion compared with invasive melanoma. This may reduce patient anxiety and allow for management decisions that align with their values and preferences.