The Clinicopathological and Survival Profiles Comparison Across Primary Sites in Acral Melanoma

Abstract

Background. The clinicopathological and survival profiles across primary sites in acral melanoma (AM) are still controversial and unclear. Methods. This is a multi-center retrospective study. Clinicopathological data of AM patients diagnosed between 1 January 2000 and 31 December 2017 from 6 large tertiary hospitals in China were extracted. Chi square tests were used to compare basic characteristics between primary sites of sole, palm and nail bed. Melanomaspecific survival (MSS) differences based on primary sites were compared by log-rank tests and multivariate Cox regressions were used to identify prognostic factors for MSS. Results. In total, 1157 AM patients were included. The sole group had a more advanced initial stage, deeper Breslow thickness, higher recurrence rate and distant metastases risk (all P \ 0.05). The proportion of age \ 65 years and ulceration were statistically lower in nail bed and palm groups, respectively. A total of 294 patients underwent sentinel lymph node biopsy and rates of positive SLN status had no statistical difference across primary sites. Among 701 patients with genetic profiles, the mutational frequency of BRAF, C-KIT, and PDGFRA were similar except for NRAS (higher in sole group, P = 0.0102). The median MSS of sole, nail bed and palm patients were 65.0 months, 112.0 months, and not reached, respectively (log-rank P = 0.0053). In multivariate analyses, primary site, initial stage, ulceration and recurrence were the prognostic factors for MSS in overall population, but the statistical significance varied over primary sites. Conclusions. Substantial clinicopathological and survival heterogeneities exist across different primary sites in the AM population. Sole melanoma has worse prognosis compared with palm and nail bed subtypes. Melanoma is a malignancy with a steadily increasing incidence worldwide. Acral melanoma (AM) is a term referring to the melanoma affecting soles, palms, and nail beds. 1 It is documented as the least common subtype in Caucasians but constitutes up to 50-75% in populations of color. 2-5

Caucasians with acral lentiginous melanoma have the same outcome as patients with stage- and limb-matched superficial spreading melanoma

“…Accordingly, Eriksson et al ( 2015 ) prospectively studied 4237 melanoma patients of all tumor subtypes and did not observe that melanoma-specific death rates differ between ALM and SSM patients. As also observed in the present study, positive SLNB is the strongest predictor of disease relapse and melanoma-specific death (Wei et al 2020 ). Similar to our approach, Huayllani et al ( 2020 ) compared a large sample of AML ( n = 5203) with patients with melanomas located on the limbs, exclusively ALM (Huayllani et al 2020 ).…”

Immune Checkpoint Inhibitors in Advanced Acral Melanoma: A Systematic Review

“…According to a multi-center retrospective study in China, there exist differences in survival in different primary locations in AM. Compared with AM arising from sole, AM arising from palm and nail bed subgroup has a better prognosis ( 49 ). AM in different anatomical positions may have variable mutation profiles, which is exemplified by the study result that BRAF mutations were more often found in AM located on the feet.…”

Immunotherapy in Acral and Mucosal Melanoma: Current Status and Future Directions

“…The study also showed that initial tumor stage and ulceration were significant predictors of melanoma-specific survival. Intriguingly, patients with primary melanomas on the soles of their feet had a worse prognosis than those with primary lesions on the palms and under the nails (39).…”

“…However, the higher tumor thickness and ulceration rates in Asian patients with melanoma compared with their Caucasian counterparts may reflect differences in the clinicopathological characteristics of acral and cutaneous melanomas, such as the higher aggressiveness of acral melanomas (35). In a recent study of 1157 Chinese patients with acral melanoma, Wei et al (39) showed that patient prognosis varied depending on the anatomical location of the primary tumor. The study also showed that initial tumor stage and ulceration were significant predictors of melanoma-specific survival.…”