Acral melanoma: a retrospective cohort from the Brazilian National Cancer Institute (INCA)

Abstract

Acral melanoma (AM) is a rare subtype of melanoma arising on the palms, soles and subungual areas. In the Brazilian and Latin American populations, the sociodemographic and clinical-pathologic features of AM are unclear. AM tends to be more advanced at presentation because of delayed diagnoses, with poor survival. This study reports on a retrospective AM cohort from the Brazilian National Cancer Institute. We reviewed a database of 529 patients presenting with AM from 1997 to 2014 and analysed the sociodemographic and clinical-pathologic features of AM associated with overall survival and relapse-free survival. All patients were Brazilian, ranging in age from 19 to 101 years (mean 65.4; median 67.0). Two hundred and ninety-four (55.8%) patients were women. The Breslow primary lesion thicknesses ranged from 0.0 to 65.0 mm (mean 8.3 mm; median 5.0 mm). Of these patients, 43.3% had the acral lentiginous histologic subtype. Plantar was the most frequently involved site (68.5%), and ulcers and mitosis were present in 79.0 and 86.4% of these cases, respectively. Multivariate analysis results found that Breslow thickness of 1.03 (95% confidence interval: 1.01-1.05; P=0.01) and ulceration of 2.70 (95% confidence interval: 1.00-7.06; P=0.05) were poor prognostic indicators of overall survival. AM tumours were thick on diagnostic tests and were associated with poorer survival outcomes. Unfavourable prognosis likely derives from the delayed diagnosis compared with other melanoma subtypes.

Clinicopathological Features and Prognostic Factors of Primary Acral Melanomas in Caucasians

“…We have also shown that the most common histological subtype in HFM is ALM, which stays in concordance with studies of other authors such as Durbec et al, Albreski et al,Jung et al,Nunes et al [2,9,28,30]. Many HFMs were ulcerated (62.4%), which is consistent with the retrospective literature in this MM group [2,30,33]. In the HFM group, we found a higher median Breslow thickness (3.3 mm) than reported by Bello (2.1 mm) [5] but thinner than in the Nunes cohort (5.0 mm) [30].…”

“…In our study, the median age in the non-HFM cohort was 52.5 years old, which is consistent with data in the literature [31]. There were slightly more women in the HFM (59.5%) and SUM groups (58.7%), which is consistent with the previous literature [11,30,32]. We have also shown that the most common histological subtype in HFM is ALM, which stays in concordance with studies of other authors such as Durbec et al, Albreski et al,Jung et al,Nunes et al [2,9,28,30].…”

“…We confirmed a reduced survival in the HFM group vs. patients with MMs in other sites, as observed in previous studies [5,30]. The five-year survival rate in HFM patients was 59.3%, in line with the literature reporting a range of 59-63% [7,8].…”

“…Many HFMs were ulcerated (62.4%), which is consistent with the retrospective literature in this MM group [2,30,33]. In the HFM group, we found a higher median Breslow thickness (3.3 mm) than reported by Bello (2.1 mm) [5] but thinner than in the Nunes cohort (5.0 mm) [30]. In Durbec et al's review of HFM, melanoma was more frequently located on the foot than on the hand, with hand/foot melanoma distribution ranging from 1/13 to 1/4, which is similar to our results in which foot melanoma constituted 84.6% of all HFM [28].…”

“…Some studies show that only a higher stage at diagnosis is the predictor for a shorter survival rate [34]. Multivariate analysis in Slingluff et al's study on stage I acral melanomas showed that race and ulceration were significant as independent factors while in Nunes et al's study, Breslow thickness and ulceration were independent factors for HFM [29,30]. Differences between our cohort compared to other groups may arise from a different ethnical or genetic profile of MMs, as a result of, for example, a difference in exposure to UVR.…”