Prognostic value of ulceration varies across Breslow thicknesses and clinical stages in acral melanoma: a retrospective study

Ulceration is regarded as an adverse prognostic factor and used together with tumor thickness to subcategorize cutaneous melanoma patients. However, the prognostic impact of ulceration in acral melanoma (AM) is controversial.

Assess the prognostic impact of ulceration in AM and the variability across different Breslow thicknesses and clinical stages.

A multi-center retrospective study of patients diagnosed with AM between Jan 2000 and Dec 2017. Differences in melanoma-specific survival (MSS) between patients with and without ulceration were assessed using the multivariable Cox proportional hazards model and log-rank test.

Among 1053 enrolled patients, 62.6% had ulceration. After a median follow-up of 61 months, patients with ulceration had a lower median MSS vs. those without [66.1 months (95% confidence interval, 95% CI 60.0-86.0) vs. not reached; hazard ratio (HR) =1.41, 95% CI 1.09-1.82; P-value=0.012]. Among patients with thin (?1 mm) melanoma, the survival curves of patients with vs. without ulceration clearly separated over time (P-value<.001). No association between ulceration and MSS was observed for melanomas of thickness >1 mm (Subgroups of T2, T3 and T4; all P-values>0.05) or with stage III disease (HR=1.09, 95% CI 0.71-1.68, P-value=0.391).

Ulceration is an independent negative prognostic factor for patients with AM but the impact varies across Breslow thicknesses and clinical stages. Ulceration has a significant effect on prognosis for patients with thin (?1 mm) melanoma, but there was no association between ulceration and survival in intermediate/thick or stage III AM.