Risk of haematologic malignancies among cutaneous melanoma survivors: A population-based analysis using large-scale queensland cancer registry data.

BACKGROUND

Queensland has the world's highest incidence of cutaneous melanoma, creating a large survivor population at risk of second primary cancers. This population-based study investigated the association between melanoma and subsequent haematological malignancies (HM) in Queensland, Australia.

METHODS

A retrospective cohort study was conducted using Queensland Cancer Registry data from 2012 to 2022, including residents diagnosed with invasive melanoma. Individuals were followed until 2022, and Standardised Incidence Ratios (SIRs) were calculated based on expected cases in the general population. Analyses were stratified by sex, age, and HM subtype according to the 2024 WHO classification of haematolymphoid tumours.

RESULTS

Melanoma survivors demonstrated a significantly increased risk of developing a haematologic malignancy compared with the general population (SIR 1.88, 95% CI 1.69-2.09). The greatest excesses were observed for plasma-cell neoplasms (SIR 1.81, 95% CI 1.58-2.07) and mature B-cell malignancies, including chronic lymphocytic leukaemia/small lymphocytic lymphoma (SIR 1.60, 95% CI 1.41-1.81). Risks were highest among individuals aged 50-79 years and were consistently greater in men (myeloma SIR 1.97; CLL/SLL 1.74) than in women (myeloma SIR 1.68; CLL/SLL 1.49). In contrast, myeloproliferative neoplasms occurred less frequently than expected (SIR 0.69, 95% CI 0.55-0.86). Temporal analyses showed the highest relative risk within one year of melanoma diagnosis, declining but remaining elevated beyond five years.

CONCLUSIONS

Queensland melanoma survivors experience a persistent and subtype-specific excess of haematological malignancies, particularly plasma-cell and mature B-cell neoplasms. The pattern of risk supports a multifactorial aetiology involving immune modulation, age-related clonal haematopoiesis, and treatment-related influences rather than surveillance bias alone. These findings underscore the importance of risk-aware, symptom-triggered follow-up and the need for future linkage of clinical, therapeutic, and genomic data to inform personalised survivorship care.