The genetic evolution of acral melanoma.

Acral melanoma is an aggressive type of melanoma with unknown origins. It is the most common type of melanoma in individuals with dark skin and is notoriously challenging to treat. We examine exome sequencing data of 139 tissue samples, spanning different progression stages, from 37 patients. We find that 78.4% of the melanomas display clustered copy number transitions with focal amplifications, recurring predominantly on chromosomes 5, 11, 12, and 22. These complex genomic aberrations are typically shared across all progression stages of individual patients. TERT activating alterations also arise early, whereas MAP-kinase pathway mutations appear later, an inverted order compared to the canonical evolution. The punctuated formation of complex aberrations and early TERT activation suggest a unique mutational mechanism that initiates acral melanoma. The marked intratumoral heterogeneity, especially concerning MAP-kinase pathway mutations, may partly explain the limited success of therapies for this melanoma subtype.

Insulin-like growth factor 2 mRNA-binding protein 3 enhanced melanoma migration through regulation of AKT1 and RELA expression.

IMP-3 expression is a poor prognostic factor of melanomas and it promotes melanoma cell migration and invasion by a pathway modulating HMGA2 mRNA expression. We tried to identify other putative targets of IMP-3. We identified putative IMP-3-binding RNAs, including AKT1, MAPK3, RB1 and RELA, by RNA immunoprecipitation coupled with next-generation sequencing. IMP-3 overexpression increased AKT and RELA levels in MeWo cells. siRNAs against AKT1 and RELA inhibited MeWo/Full-length IMP-3 cell migration. IMP-3 knockdown of A2058 cells decreased AKT1 and RELA expression and lowered migration ability. Co-transfection of A2058 cells with AKT1- or RELA-expressing plasmids with IMP-3 siRNA restored the inhibitory effects of IMP-3 knockdown on migration. HMGA2 did not influence AKT1 and RELA expression in melanoma cells. Human melanoma samples with high IMP-3 levels also showed high HMGA2, AKT1 and RELA expression. Our results show that IMP-3 enhances melanoma cell migration through the regulation of the AKT1 and RELA axis.

Anatomic mapping of acral melanocytic nevi and acral lentiginous melanomas among Taiwanese patients: A retrospective cohort study.

BACKGROUND: The early diagnosis of acral lentiginous melanoma (ALM) contributes to clinical outcomes since ALM can be mistaken for acral melanocytic nevus (AMN). ALM occurrence is reported to correlate with stress-bearing areas, which may assist in differential diagnoses. Our objective is to evaluate the distribution patterns of ALMs and AMNs on the palms and soles among Taiwanese patients. METHODS: A retrospective analysis was performed by reviewing the charts of 1400 patients diagnosed with benign and malignant pigmented lesions confirmed after excisional biopsy at our institution between 2000 and 2022 in Taiwan. Correlations between lesions and clinicopathological factors were analyzed. RESULTS: 309 AMNs and 177 ALMs were included. Mechanical stress was significantly associated with plantar ALMs (weight-bearing area: 92.65 %, arch: 7.35 %, P < 0.001). Significant differences in the distribution patterns were observed for plantar ALMs compared with all AMNs (P < 0.001) and non-atypical AMNs (P < 0.001), but were not observed between palmar AMNs and ALMs. CONCLUSION: Plantar ALMs were most commonly observed on the weight-bearing areas of the soles, distinct from the distribution of all AMNs and of non-atypical AMNs. The distribution features and anatomic mapping of ALMs may facilitate the early clinical diagnosis of ALM.

The genetic evolution of acral melanoma.

Acral melanoma is an aggressive type of melanoma with unknown origins, arising on the sole, palm, or nail apparatus. It is the most common type of melanoma in individuals with dark skin and is notoriously challenging to treat. Our study examined exome sequencing data from 139 tissue samples, spanning different progression stages, collected from 37 patients. We found that 78.4% of the melanomas displayed one or more clustered copy number transitions with focal amplifications, recurring predominantly on chromosomes 5, 11, 12, and 22. These genomic "hailstorms" were typically shared across all progression stages within individual patients. Genetic alterations known to activate TERT also arose early. By contrast, mutations in the MAP-kinase pathway appeared later during progression, often leading to different tumor areas harboring non-overlapping driver mutations. We conclude that the evolutionary trajectories of acral melanomas substantially diverge from those of melanomas on sun-exposed skin, where MAP-kinase pathway activation initiates the neoplastic cascade followed by immortalization later. The punctuated formation of hailstorms, paired with early TERT activation, suggests a unique mutational mechanism underlying the origins of acral melanoma. Our findings highlight an essential role for telomerase, likely in re-stabilizing tumor genomes after hailstorms have initiated the tumors. The marked genetic heterogeneity, in particular of MAP-kinase pathway drivers, may partly explain the limited success of targeted and other therapies in treating this melanoma subtype.

Survival benefit of sentinel lymph node biopsy in Asian melanoma patients.

Sentinel lymph node biopsy (SLNB) provides important prognostic information for early-stage melanomas. However, statistics regarding the survival comparison between SLNB and nodal observation in Asia, where acral lentiginous melanoma (ALM) predominates, are limited. This study aimed to identify if SLNB offered survival benefits over nodal observation in early-stage melanomas in Taiwan. The retrospective study included 227 patients who met the SLNB criteria according to the National Comprehensive Cancer Network guidelines and were treated at National Taiwan University Hospital from June 1997 to June 2021. Survival analysis was performed using Kaplan-Meier curves and Cox proportional hazards regression models. Of the study population, ALM accounted for 73.1%; 161 patients (70.9%) underwent SLNB and 66 patients (29.1%) were under nodal observation. Multivariate analysis showed significantly improved melanoma-specific survival (hazard ratio [HR], 0.6; p = .02) in the SLNB group. Among those who underwent completion lymph node dissection (CLND), the non-sentinel node positivity rate was 44.4%. Immediate CLND resulted in significantly longer melanoma-specific survival and distant-metastasis-free survival (DMFS) compared to nodal observation. (HR, 0.2; p = .01 for melanoma-specific survival. HR, 0.3; p = .046 for DMFS). In conclusion, SLNB may provide survival benefits of cutaneous melanoma over nodal observation in the Taiwanese population.

Risk factors for lymphatic and hematogenous metastasis after diagnosis of cutaneous Melanoma in Taiwan.

BACKGROUND: Risk factors of lymphatic and hematogenous metastasis in cutaneous melanoma remained unclear in Asian population. This study aimed to identify clinical and histopathological factors to predict metastatic pathways in cutaneous melanoma in Taiwan. METHODS: A total of 247 patients diagnosed as stage I and II melanoma, followed at National Taiwan University Hospital were included in this retrospective study from 1980 to 2020. Kaplan-Meier curves and Cox proportional hazards regression were utilized to identify risk factors. RESULTS: During a median follow-up of 143 months, 48 (19.4%) and 62 (25.1%) patients developed lymphatic and hematogenous metastasis respectively. In the univariate analysis, age> 70 years, greater Breslow thickness, ulceration, neurotropism, and NRAS mutation were significant risk factors for lymphatic metastasis in all subtypes of melanoma. Age >70 years, head and neck location, thickness, ulceration, higher mitotic rate, neurotropism, and NRAS mutation were significant predictors of hematogenous metastasis in all subtypes. In the multivariate analysis, greater thickness (HR for 2.0-4.0 mm, 4.5; p = .009 and HR for >4.0 mm, 5.7; p = .003) retained its significance as an independent risk factor for lymphatic metastasis in all subtypes of melanoma. Thickness (HR for >4.0 mm, 5.7; p < .001) and ulceration (HR, 2.5; p = .001) were independent risk factors for hematogenous metastasis. CONCLUSION: Risk factors of metastasis not only differ between lymphatic and hematogenous pathways, but also differ between ethnics and melanoma subtypes. Better understanding the behavior of cutaneous melanoma may help guide further treatments and follow-up plans.

Clinicopathological characteristics and prognosis in significantly thick acral lentiginous melanoma in Taiwan.

This retrospective cohort study enrolled 385 patients diagnosed with cutaneous melanoma from 1980 to 2021 in National Taiwan University Hospital (NTUH). The aim of this study was to investigate the relationship between thickness of primary melanoma lesions and disease outcome of melanoma patients, in particular, those diagnosed with acral lentiginous melanoma (ALM). The association between important clinicopathological characteristics other than tumor thickness and disease outcome was also analyzed. Survival analyses with the Kaplan-Meier method were utilized to investigate the prognoses of patients with different lesion thickness. The male-to-female ratio was 1.12:1. The median age at diagnosis was 63 years old (mean: 62.2 years). There were 283 cases (73.5%) of acral lentiginous melanoma (ALM) with a male-to-female ratio of 1.04:1. Between patients with primary ALM lesions 4.1 millimeters (mm) to 8.0 mm thick and those with lesions over 8.0 mm thick, significant differences in prognostic outcomes including incidence of second recurrences within 1 year (raw p = 0.003, Bonferroni corrected p = 0.009) and distant metastases within 1 year (raw p = 0.003, Bonferroni corrected p = 0.008), were observed. Significantly worse 1-year (raw p = 0.01, Bonferroni corrected p=0.03) and 2-year survival (raw p = 0.006, Bonferroni corrected p = 0.02) were found in ALM patients with lesions of over 8 mm thick than those with lesions 4.1 mm to 8.0 mm at diagnosis. Vigilant short-term follow-up is warranted in ALM patients with lesions of over 8.0 mm thick at diagnosis due to higher risks of adverse outcome.

Risk factors of recurrence and distant metastasis in primary cutaneous melanoma in Taiwan.

Risk factors of recurrence and distant metastasis of acral lentiginous melanoma (ALM) are of great interest for the high percentage of ALM in cutaneous melanoma in Asian populations. This single-center retrospective cohort including 177 patients with localized melanoma diagnosed from 2004 to 2020 aims to identify adverse predictors in cutaneous melanoma in Taiwan, with a focus on ALM. The relationship between clinicopathological features and outcomes, including incidences of recurrence and distant metastasis in 5 years from diagnosis, was analyzed. This study included 124 patients (70.1%) with ALM and 53 (29.9%) with non-ALM melanoma. Regarding clinicopathological characteristics, ALM patients were diagnosed at an older age and received sentinel lymph node biopsies (SLNBs) more often, while adjacent melanocytic nevi were more prevalent in non-ALM patients. With respect to prognostic implications of clinicopathological features, in ALM, implementation of SLNB was associated with a lower 5-year distant metastasis rate. Thickness of melanoma lesions over 4 mm, ulceration, and neurotropism, were related to both higher 5-year recurrence and distant metastasis rates. With regard to non-ALM patients, diagnoses made at or over 65 years old was linked to a higher 5-year recurrence rate, whereas ulceration was associated with both higher 5-year recurrence and distant metastasis rates. In conclusion, several clinicopathological characteristics have been identified to be associated with poor prognosis of cutaneous melanoma, especially ALM.

Purpuric drug eruptions induced by EGFR tyrosine kinase inhibitors are associated with IQGAP1-mediated increase in vascular permeability.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are used as a treatment for non-small-cell lung cancer. There have been some reports of EGFR-TKIs being associated with vascular adverse events. We found that EGFR-TKIs decreased the proliferation of HMEC-1s (immortalized human dermal microvascular endothelial cells) and HMVECs (human dermal microvascular endothelial cells), and also inhibited the phosphorylation of EGFR and ERK. We examined the mRNA expression profile of erlotinib-treated HMEC-1s and identified IQ motif containing GTPase activating protein 1 (IQGAP1) as the most consistently up-regulated transcript and protein. IQGAP1 was also overexpressed and co-localized with endothelial cells in the lesional skin. Notably, increased IQGAP1 expression was associated with decreased transendothelial electrical resistance and increased vascular permeability in vitro. Erlotinib treatment enriched the staining of IQGAP1 and reduced the intensities of α-catenin at the sites of cell-cell contact. In conclusion, erlotinib induces adherens junction dysfunction by modulating the expression of IQGAP1 in dermal endothelial cells. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

miR-519d Promotes Melanoma Progression by Downregulating EphA4.

Increasing evidence suggests that there is a unique cell subpopulation in melanoma that can form nonadherent melanospheres in serum-free stem cell medium, mimicking aggressive malignancy. Using melanospheres as a model to investigate progression mechanisms, we found that miR-519d overexpression was sufficient to promote cell proliferation, migration, invasion, and adhesion in vitro and lung metastatic capability in vivo The cell adhesion receptor EphA4 was determined to be a direct target of miR-519d. Forced expression of EphA4 reversed the effects of miR-519d overexpression, whereas silencing of EphA4 phenocopied the effect of miR-519d. Malignant progression phenotypes were also affected at the level of epithelial-to-mesenchymal transition and the ERK1/2 signaling pathway inversely affected by miR-519d or EphA4 expression. In clinical specimens of metastatic melanoma, we observed significant upregulation of miR-519d and downregulation of EphA4, in the latter case correlated inversely with overall survival. Taken together, our results suggest a significant functional role for miR-519d in determining EphA4 expression and melanoma progression.Significance: These results suggest a significant role for miR-519d in determining expression of a pivotal cell adhesion molecule that may impact risks of malignant progression in many cancers. Cancer Res; 78(1); 216-29. ©2017 AACR.

A clinicopathological analysis of 153 acral melanomas and the relevance of mechanical stress.

The pathogenesis of melanomas emerging in plantar surfaces remains unclear; however, mechanical stress has been reported to increase the formation of melanomas. In this study, we conducted a multicenter retrospective analysis of 153 acral melanomas diagnosed between 2000 and 2015 in Taiwan. The male-to-female ratio of the patients in question was 1:1.28, and the mean age at diagnosis was 68 years. We examined whether melanomas which developed in different areas of the patients' soles differed in their associations with various clinicopathological characteristics and survival. Testing by goodness of fit indicated that stress-bearing areas were significantly more conducive to the generation of melanomas than non-stress-bearing areas (P < 0.0001). More specifically, compared to the arch, the rear of the foot and front of the foot were significantly more conducive to the generation of melanomas (P < 0.0001 and P < 0.0001, respectively). The distribution pattern was not associated with differences in age, gender, right/left foot involvement, ulceration, mitosis, lymph node metastasis, tumor thickness, or stage. The overall, distant metastasis-free, and recurrence-free survival rates did not differ significantly between the stress-bearing and non-stress-bearing areas. Furthermore, while acral melanomas tended to develop on stress-bearing areas, the distribution pattern was not associated with the prognostic index or survival.

Clinicopathological features and prognosis of patients with de novo versus nevus-associated melanoma in Taiwan.

Studies surveying melanomas associated with melanocytic nevi in Asia are rare. In this study, we examined whether nevus-associated melanomas differ from de novo melanomas in terms of their associations with clinical factors, histologic characteristics, and patient survival in Taiwan. Using data on cancer cases obtained from the Department of Pathology archives and the Cancer Registry of National Taiwan University Hospital, we conducted a retrospective analysis of 103 consecutive melanoma patients who were diagnosed between 2010 and 2015 and received follow-up through November 2016. Approximately 17.5% of the melanomas in question were associated with a nevus. In patients under 65 years of age, non-acral lentiginous melanomas were significantly associated with a higher percentage of nevus-associated melanomas. The superficial spreading subtype, younger patient age, thinner tumor, intermittent solar exposure, and early stage were significant predictors of a melanoma being histologically associated with a nevus. The appearance of a nevus associated with a melanoma predicted better recurrence-free survival compared with de novo melanomas. Although acral lentiginous melanomas (70.9%) constituted the most common histologic subtype, only 9.6% of the acral lentiginous melanomas were associated with a nevus. Furthermore, there was no statistically significant difference between the nevus-associated and de novo acral lentiginous melanomas with regard to clinicopathological factors and survival. In conclusion, nevus-associated melanomas were uncommon among acral lentiginous melanomas. Relatedly, because over half of all melanomas in Asians are acral lentiginous melanomas, Asians are less likely than Caucasians to have nevus-associated melanomas.

Purpuric Drug Eruptions Caused by Epidermal Growth Factor Receptor Inhibitors for Non-Small Cell Lung Cancer: A Clinicopathologic Study of 32 Cases.

Importance: Purpuric skin lesions have only rarely been reported in patients receiving epidermal growth factor receptor inhibitors. However, their clinical and histopathologic presentations have varied considerably. Objective: To characterize purpuric skin eruptions caused by epidermal growth factor receptor inhibitors. Design, Setting, and Participants: This prospective study enrolled 32 patients who presented to an integrated dermato-oncologic clinic in a tertiary referral medical center with purpuric skin lesions after using epidermal growth factor receptor inhibitors from January 1, 2013, through December 31, 2015. Exposures: Epidermal growth factor receptor tyrosine kinase inhibitors, including gefitinib, erlotinib, and afatinib. Main Outcomes and Measures: Clinical presentations, histopathologic features, laboratory examinations, and treatment outcomes of patients with purpuric drug eruptions. Results: Thirty-two patients, 14 with purpuric drug eruptions without pustules (mean [SD] age, 60 [11] years; 12 female and 2 male) and 18 with purpuric drug eruptions with pustules (mean [SD] age, 64 [11] years; 12 female and 6 male), were identified. The median time to development of skin lesions was 3.5 months. The clinical presentations were characterized by purpuric macules, papules, and confluent plaques predominantly on the lower extremities. Pustules in various sizes could be found in 18 patients (56%). Eleven patients (34%) had skin lesions that covered places other than the lower extremities. Eczema craquelé-like features developed in 13 patients (41%). Bacterial pathogens were frequently identified in these skin lesions. Among them, Staphylococcus aureus was the most predominant and was found in 20 patients (63%), commonly in those with cutaneous pustules. Epidermal dysmaturation, neutrophil exocytosis, perivascular infiltration of lymphocytes and neutrophils, red blood cell extravasation, and plumping endothelium were the main histopathologic features. The expressions of filaggrin and human ß-defensin 2 in lesional skin of these patients were markedly reduced. All patients improved after receiving at least 1 week of systemic antibiotic treatment; the doses of epidermal growth factor receptor inhibitors were also changed for 14 patients (44%). Conclusions and Relevance: Purpuric drug eruptions caused by epidermal growth factor receptor inhibitors are uncommon and have characteristic clinical and histopathologic presentations. The role of bacterial pathogens in this reaction is important and requires further exploration.

Frequent PIK3CA activating mutations in nipple adenomas.

AIMS: Nipple adenoma (NA) is a rare benign epithelial tumour occurring in the nipple. Histologically, it exhibits variable and often mixed adenosis-like and usual ductal hyperplasia-like growth patterns. Morphologically, it is similar to other benign proliferative breast lesions occurring in the breast parenchyma, which have been shown to harbour activating mutations in PIK3CA, AKT1 or, less frequently, in RAS in more than 50% of cases. In this study, we aimed to analyse the mutation status of PIK3CA, AKT1, RAS and BRAF in NAs and correlated the mutation status with the histological features. METHODS AND RESULTS: Mutation analysis of PIK3CA, AKT1, RAS and BRAF was performed in 24 NAs by Sanger sequencing. Our results showed that activating PIK3CA mutations were identified in eight of the 15 NAs (53%) with a predominantly adenosis-like pattern and four of the nine NAs (44%) with a predominantly usual ductal hyperplasia-like pattern. One tumour with a PIK3CA H1047R mutation also had a KRAS Q61H mutation. Two tumours with an adenosis-like pattern had BRAF V600E mutations. Overall, half of the NAs (12 of 24, 50%) in our series had PIK3CA mutations and 58% (14 of 24) had PIK3CA, RAS or BRAF mutations. CONCLUSIONS: Our data indicate that, similar to other benign proliferative lesions occurring in the breast parenchyma, activating PIK3CA mutations are very common in NAs, and KRAS mutation may occur concurrently with PIK3CA mutation. In addition, as BRAF mutation has not been identified in benign proliferative lesions in previous studies, BRAF-mutated NAs appear to have distinct pathogenesis.

Frequent PIK3CA-activating mutations in hidradenoma papilliferums.

Hidradenoma papilliferum (HP) is a benign epithelial tumor most commonly seen in the vulva. It is proposed to be derived from the anogenital mammary-like glands and is histologically very similar to the mammary intraductal papilloma (IP). Approximately 60% of mammary IPs have activating mutations in either PIK3CA or AKT1, with each gene accounting for 30% of cases. In this study, we screened the mutation statuses of PIK3CA, AKT1, RAS, and BRAF in 30 HPs. The results showed that activating mutations in either PIK3CA or AKT1 were identified in 20 tumors (67%); 19 tumors had PIK3CA mutations (63%; 13 in exon 20 and 6 in exon 9), and 1 had an AKT1 E17K mutation (3%). BRAF V600E mutation was found in an HP that also had a PIK3CA H1047R mutation. No RAS mutation was found. The mutation status was not correlated with the degree of epithelial cell hyperplasia. We conclude that although there might be site-related variations in the mutation frequencies of PIK3CA and AKT1 genes, HP is histologically and also genetically very similar to the mammary IP, suggesting that HP can be viewed as the extramammary counterpart of mammary IP.

Insulin-Like Growth Factor II mRNA-Binding Protein 3 Expression Correlates with Poor Prognosis in Acral Lentiginous Melanoma.

Insulin-like growth factor-II mRNA-binding protein 3 (IMP-3) is an RNA-binding protein expressed in multiple cancers, including melanomas. However, the expression of IMP-3 has not been investigated in acral lentiginous melanoma (ALM). This study sought to elucidate its prognostic value in ALMs. IMP-3 expression was studied in 93 patients diagnosed with ALM via immunohistochemistry. Univariate and multivariate analyses for survival were performed, according to clinical and histologic parameters, using the Cox proportional hazard model. Survival curves were graphed using the Kaplan-Meier method. IMP-3 was over-expressed in 70 out of 93 tumors (75.3%). IMP-3 expression correlated with thick and high-stage tumor and predicted poorer overall, melanoma-specific, recurrence-free and distant metastasis-free survivals (P = 0.002, 0.006, 0.008 and 0.012, respectively). Further analysis showed that patients with tumor thickness ≤ 4.0 mm and positive IMP-3 expression had a significantly worse melanoma-specific survival than those without IMP-3 expression (P = 0.048). IMP-3 (hazard ratio 3.67, 95% confidence intervals 1.35-9.97, P = 0.011) was confirmed to be an independent prognostic factor for melanoma-specific survival in multivariate survival analysis. Positive IMP-3 expression was an important prognostic factor for ALMs.

TERT promoter mutations in periocular carcinomas: implications of ultraviolet light in pathogenesis.

BACKGROUND/AIMS: Ultraviolet light-signature mutations in the telomerase reverse transcriptase (TERT) gene promoter have been identified in cutaneous melanomas, basal cell carcinomas (BCCs), and squamous cell carcinomas (SCCs). Whether these mutations also occur in periocular tumours, including periocular sebaceous carcinomas (PSCs) and in situ tumours, has not been studied. METHODS: DNA extraction, PCR and Sanger sequencing were used to determine the frequency of TERT promoter mutations in periocular tumours. The presence of mutations was correlated with histological evidence of solar elastosis. RESULTS: Sixty-three tumours were analysed. TERT promoter mutations were identified in 18 of 22 BCCs (82%), 6 of 10 SCCs (60%), 1 of 2 in situ SCCs (50%), 4 of 9 grade III conjunctival intraepithelial neoplasia (CIN III) (44%) and 0 of 20 PSCs (0%). For BCCs, TERT promoter mutations were not associated with the histological risk categories of the tumours. For CIN III cases, all of the three lesions with solar elastosis had TERT promoter mutations, whereas the mutation was found in only one of the six CIN III cases without solar elastosis. CONCLUSIONS: We demonstrate that ultraviolet light-signature TERT promoter mutations are very common in periocular BCCs, SCCs and CIN III lesions, indicating important roles of ultraviolet light in the pathogenesis of these tumours. In addition, the mutations are present in in situ stage. By contrast, no TERT promoter mutation is found in PSCs.