The prognostic impact of pregnancy-associated melanoma on overall and melanoma-specific survival: A systematic review and meta-analysis.

BACKGROUND

Pregnancy-associated melanoma (PAM) - melanoma diagnosed during pregnancy or within 12 months postpartum - raises concern that physiological immune adaptations may worsen tumour outcomes, yet whether PAM independently confers worse survival remains unresolved.

METHODS

We searched PubMed/MEDLINE, Scopus, Cochrane CENTRAL, and ClinicalTrials.gov for observational studies comparing survival in PAM versus non-PAM women reporting adjusted hazard ratios. Risk of bias was assessed with ROBINS-E. Four pre-specified random-effects meta-analyses (REML; Hartung-Knapp adjustment) were stratified by timing (antepartum, postpartum) and outcome (overall survival [OS], melanoma-specific survival [MSS]).

RESULTS

From 454 deduplicated records, 11 studies entered qualitative synthesis and 3 low-risk-of-bias studies (16,467 women; 1662 PAM) were meta-analysed. Neither antepartum (HR 1.13, 95% CI 0.19-6.70; I²=65.6%) nor postpartum PAM (HR 1.14, 95% CI 0.39-3.38; I²=54.8%) showed a significant OS difference; MSS analyses were similarly null. Sensitivity analyses restricted to staged cases eliminated heterogeneity entirely, shifting estimates toward protection (antepartum HR 0.78, 95% CI 0.44-1.39). Stage-matched evidence yielded a borderline-significant pooled HR of 0.85 (95% CI 0.73-1.00; I²=0%) favouring PAM.

CONCLUSIONS

PAM does not independently worsen OS or MSS when stage is adequately controlled. Observed heterogeneity reflects incomplete stage ascertainment rather than true biological variation. Future registries must adopt standardised PAM definitions and ensure complete staging to yield reliable survival estimates.