Melanoma in situ: Exploring Perceived Risk and Management Preferences
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Open Access
Type
ThesisThesis type
Masters by ResearchAuthor/s
Wu, ZhuohanAbstract
Background:
Melanoma incidence trends in Australia show a pattern of overdiagnosis, largely driven by increasing diagnoses of melanoma in situ (MIS), now over twice as common as invasive melanoma. Evidence suggests MIS is a risk factor rather than an obligate precursor to invasive ...
See moreBackground: Melanoma incidence trends in Australia show a pattern of overdiagnosis, largely driven by increasing diagnoses of melanoma in situ (MIS), now over twice as common as invasive melanoma. Evidence suggests MIS is a risk factor rather than an obligate precursor to invasive disease. The term “melanoma” may cause psychological harm, as patients often do not distinguish in situ from invasive melanoma, leading to anxiety, fear of recurrence, and potential healthcare overuse. Renaming MIS has been proposed to reduce perceived risk and support de‑escalation of management. Aim: This MPhil examines how the MIS diagnostic label affects perceived risk and management decisions. Methods: A large online randomised experiment was conducted among Australian adults without melanoma. Participants received one of three labels for the same low‑risk lesion: “melanoma in situ,” “low‑risk melanocytic neoplasm,” or “low‑risk melanocytic neoplasm, in situ.” Perceived risk (absolute, comparative, experiential, vulnerability) and perceived melanoma mortality were assessed and compared with modelled risk estimates. Free‑text responses on perceived mortality risk, treatment, and follow‑up preferences were analysed using qualitative content analysis. Results: Alternative labels reduced perceived risk across all constructs and lessened, though did not eliminate, overestimation of invasive melanoma and melanoma mortality. Qualitative analysis showed elevated risk perception was driven by associations with the term “melanoma,” emotional responses, and limited understanding of disease progression. Diagnostic labels had less influence on follow‑up decisions than participants’ existing care habits and trust in clinicians. Conclusions: Diagnostic terminology shapes risk perception, but alternative labels alone are insufficient to align perceptions with clinical risk. Clearer prognostic communication is needed to reduce psychological harms of MIS overdiagnosis.
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See moreBackground: Melanoma incidence trends in Australia show a pattern of overdiagnosis, largely driven by increasing diagnoses of melanoma in situ (MIS), now over twice as common as invasive melanoma. Evidence suggests MIS is a risk factor rather than an obligate precursor to invasive disease. The term “melanoma” may cause psychological harm, as patients often do not distinguish in situ from invasive melanoma, leading to anxiety, fear of recurrence, and potential healthcare overuse. Renaming MIS has been proposed to reduce perceived risk and support de‑escalation of management. Aim: This MPhil examines how the MIS diagnostic label affects perceived risk and management decisions. Methods: A large online randomised experiment was conducted among Australian adults without melanoma. Participants received one of three labels for the same low‑risk lesion: “melanoma in situ,” “low‑risk melanocytic neoplasm,” or “low‑risk melanocytic neoplasm, in situ.” Perceived risk (absolute, comparative, experiential, vulnerability) and perceived melanoma mortality were assessed and compared with modelled risk estimates. Free‑text responses on perceived mortality risk, treatment, and follow‑up preferences were analysed using qualitative content analysis. Results: Alternative labels reduced perceived risk across all constructs and lessened, though did not eliminate, overestimation of invasive melanoma and melanoma mortality. Qualitative analysis showed elevated risk perception was driven by associations with the term “melanoma,” emotional responses, and limited understanding of disease progression. Diagnostic labels had less influence on follow‑up decisions than participants’ existing care habits and trust in clinicians. Conclusions: Diagnostic terminology shapes risk perception, but alternative labels alone are insufficient to align perceptions with clinical risk. Clearer prognostic communication is needed to reduce psychological harms of MIS overdiagnosis.
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Date
2026Rights statement
The author retains copyright of this thesis. It may only be used for the purposes of research and study. It must not be used for any other purposes and may not be transmitted or shared with others without prior permission.Faculty/School
Faculty of Medicine and Health, The University of Sydney School of Public HealthAwarding institution
The University of SydneyShare