Acral lentiginous melanoma: who benefits from sentinel lymph node biopsy?

Nuclear Localization of Yes-Associated Protein Is Associated With Tumor Progression in Cutaneous Melanoma

Yes-associated protein (YAP), an effector molecule of the Hippo signaling pathway, is expressed at high levels in cutaneous melanoma. However, the role of YAP in melanoma progression according to cellular localization is poorly understood. Tissues from 140 patients with invasive melanoma were evaluated by immunohistochemistry. Flow cytometry, western blotting, viability assays, wound healing assays, verteporfin treatment, and xenograft assays were conducted using melanoma cell lines B16F1 and B16F10 subjected to YapS127A transfection and siYap knockdown. Nuclear YAP localization was identified in 63 tumors (45.0%) and was more frequent than cytoplasmic YAP in acral lentiginous and nodular subtypes (P = .007). Compared with cytoplasmic YAP melanomas, melanomas with nuclear YAP had higher mitotic activity (P = .016), deeper invasion (P < .001), and more frequently metastasized to lymph nodes (P < .001) and distant organs (P < .001). Patients with nuclear YAP melanomas had poorer disease-free survival (P < .001) and overall survival (P < .001). Nuclear YAP was an independent risk factor for distant metastasis (hazard ratio: 3.206; 95% CI, 1.032-9.961; P = .044). Proliferative ability was decreased in siYapB16F1 (P < .001) and siYapB16F10 (P = .001) cells and increased in YapS127AB16F1 (P = .003) and YapS127AB16F10 (P = .002) cells. Cell cycle analysis demonstrated relative G1 retention in siYapB16F1 (P < .001) and siYapB16F10 (P < .001) cells and S retention in YapS127AB16F1 cells (P = .008). Wound healing assays showed that Yap knockdown inhibited cell invasion (siYapB16F1, P = .001; siYapB16F10, P < .001), whereas nuclear YAP promoted it (YapS127AB16F, P < .001; YapS127AB16F1, P = .017). Verteporfin, a direct YAP inhibitor, reduced cellular proliferation in B16F1 (P = .003) and B16F10 (P < .001) cells. Proliferative effects of nuclear YAP were confirmed in xenograft mice (P < .001). In conclusion, nuclear YAP in human melanomas showed subtype specificity and correlated with proliferative activity and proinvasiveness. It is expected that YAP becomes a useful prognostic marker, and its inhibition may be a potential therapy for melanoma patients.

Nail Apparatus Melanoma: Current Management and Future Perspectives

Nail apparatus melanoma (NAM) is a rare type of cutaneous melanoma that belongs to the acral melanoma subtype. NAM is managed principally in accordance with the general treatment for cutaneous melanoma, but there is scarce evidence in support of this in the literature. Acral melanoma is genetically different from non-acral cutaneous melanoma, while recently accumulated data suggest that NAM also has a different genetic background from acral melanoma. In this review, we focus on recent advances in the management of NAM. Localized NAM should be surgically removed; amputation of the digit and digit-preserving surgery have been reported. Sentinel lymph node biopsy can be considered for invasive NAM for the purpose of accurate staging. However, it is yet to be clarified whether patients with metastatic sentinel lymph nodes can be safely spared completion lymph node dissection. Similar to cutaneous melanoma, immune checkpoint inhibitors and BRAF/MEK inhibitors are used as the first-line treatment for metastatic NAM, but data on the efficacy of these therapies remain scarce. The therapeutic effects of immune checkpoint inhibitors could be lower for NAM than for cutaneous melanoma. This review highlights the urgent need to accumulate data to better define the optimal management of this rare melanoma.

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.

Sentinel Lymph Node Biopsy Positivity in Patients With Acral Lentiginous and Other Subtypes of Cutaneous Melanoma

IMPORTANCE

Acral lentiginous melanoma (ALM) is a rare subtype of malignant melanoma typically occurring on the palmar and plantar surfaces. Although it has distinctive genetic, prognostic, and behavioral characteristics relative to cutaneous melanomas overall, owing to its rarity, treatment is largely guided by data extrapolated from more common subtypes. Although sentinel lymph node (SLN) status has been shown to be a significant prognostic factor for ALM, the independent effect of ALM-subtype disease on the likelihood of SLN positivity and the stage-specific positivity rates for ALM are not well characterized.

OBJECTIVE

To evaluate the association of ALM with SLN status as well as to characterize the clinical stage-specific rates of SLN positivity for ALM based on the AJCC Cancer Staging Manual, 8th edition (AJCC-8).

DESIGN, SETTING, AND PARTICIPANTS

The National Cancer Database (NCDB) includes all reportable cases from Commission on Cancer accredited facilities and represents approximately 50% of all newly diagnosed melanoma cases in the US. This retrospective cohort study included cases of AJCC-8 clinical stage I to II melanomas from the NCDB diagnosed from 2012 to 2015. The analysis took place between April 2021 and September 2021.

EXPOSURES

Melanoma histopathologic subtype.

MAIN OUTCOMES AND MEASURES

Sentinel lymph node status.

RESULTS

We identified 60 148 patients with malignant melanomas, 959 of whom had ALM-subtype disease. Among patients in the cohort, 25 550 (42.5%) were women and the mean (SD) age was 64 (16) years. Multivariable logistic regression controlling for demographic and histopathologic characteristics revealed that ALM was independently associated with the highest risk for SLN positivity among included subtypes (vs superficial spreading melanoma: odds ratio, 1.91; 95% CI, 1.59-2.28). Subgroup analysis by AJCC clinical stage demonstrated that ALM was independently associated with the highest risk for SLN positivity for both stage IB and II disease. The rate of SLN positivity for patients with stage IB and II ALM was 18.39% (95% CI, 13.82%-24.03%) and 39.53% (34.98%-44.26%), respectively.

CONCLUSIONS AND RELEVANCE

In this cohort study ALM was independently associated with SLN positivity and had relatively high positivity rates at clinical stage IB and II. This suggests that SLNB should be encouraged for all patients with clinical stage IB and II ALM, and such patients should receive appropriate counseling about the higher regional metastatic risk of their cancers. Future work with a larger cohort is required to elucidate the risk of SLN positivity for stage IA ALM.

Different progression pattern between acral and nonacral melanoma: A retrospective, comparative, clinicoprognostic study of 492 cases of primary cutaneous melanoma according to tumor site

BACKGROUND

There are limited data regarding the difference in progression pattern between acral melanoma and nonacral melanoma.

AIMS

The objectives of this study were to compare the progression pattern between acral and nonacral melanoma and evaluate its impact on clinical outcomes.

METHODS

Clinical and histopathological features, survival outcomes and prognostic factors of 492 patients with acral melanoma or nonacral melanoma were retrospectively evaluated using the Asan Medical Center database.

RESULTS

The male-to-female ratio and the mean age was 1:0.92 and 60.2 years for acral melanoma (n = 249), and 1:0.85 and 58.4 years for nonacral melanoma (n = 243), respectively. The demographic difference was not significant. Although prediagnosis duration was longer and the advanced stage was more common in acral melanoma than that in nonacral melanoma, the vertical growth phase was more common in nonacral melanoma than that in acral melanoma, whereas, the horizontal diameter is longer in acral melanoma than that in nonacral melanoma. Dissemination to lymph nodes was more common in acral melanoma than that in nonacral melanoma. Lymph node involvement was associated with deeper Breslow thickness in nonacral melanoma but not in acral melanoma. The degree of correlation of prediagnosis duration with horizontal diameter was remarkable in acral melanoma, but with Breslow thickness in nonacral melanoma. Overall survival was worse in acral melanoma than that in nonacral melanoma. The prognostic value of Breslow thickness was more remarkable in nonacral melanoma than that in acral melanoma.

LIMITATIONS

This study is a retrospective, single-center design.

CONCLUSION

Acral melanoma has a longer radial growth phase compared with nonacral melanoma. However, acral melanoma is commonly associated with lymph node dissemination which contributed to worse survival in acral melanoma than nonacral melanoma.

Association of Histologic Regression With a Favorable Outcome in Patients With Stage 1 and Stage 2 Cutaneous Melanoma

Importance

Although regression is commonly observed in cutaneous melanoma, it is uncertain whether it is associated with patient prognosis.

Objective

To determine whether histologically confirmed regression was associated with better or worse survival in patients with primary cutaneous melanoma.

Design, Setting, and Participants

This cohort study analyzed data from 2 large cohorts of adults (one in the Netherlands and the other in Australia) with histologically proven, stage 1 and 2 primary, invasive cutaneous melanoma with known regression status treated between 2000 and 2014, with median follow-up times of 4.5 and 11.1 years for the Dutch and Australian cohorts, respectively. For the Dutch patients, population-based data from PALGA, the Dutch Pathology Registry, were used, and follow-up data were retrieved from the Netherlands Cancer Registry. For the Australian patients, data from the database of a large, specialized melanoma treatment center were used.

Main Outcomes and Measures

Multivariable Cox proportional hazards analyses were performed per cohort to assess recurrence-free survival (RFS) and overall survival (OS), and subgroup analyses according to Breslow thickness category and melanoma subtype were performed.

Results

A total of 17 271 Dutch patients and 4980 Australian patients were included. In both cohorts, survival outcomes were better for patients with disease regression. For Dutch patients, the hazard ratio (HR) for those with disease regression was 0.55 (95% CI, 0.48-0.63; P < .001) for RFS and 0.87 (95% CI, 0.79-0.96; P = .004) for OS; for the Australian patients, the HR was 0.61 (95% CI, 0.52-0.72; P < .001) for RFS and 0.73 (95% CI, 0.64-0.84; P < .001) for OS. Subgroup analyses showed that the presence of regression improved RFS within thin and intermediate Breslow thickness melanomas in both cohorts. For patients with superficial spreading melanoma (SSM) subtype, regression improved RFS and OS in both cohorts. For Dutch patients with SSM, the HR for those with disease regression was 0.54 (95% CI, 0.46-0.63; P < .001) for RFS and 0.86 (95% CI, 0.76-0.96; P = .009) for OS; for the Australian patients with SSM, the HR was 0.67 (95% CI, 0.52-0.85; P = .001) for RFS and 0.72 (95% CI, 0.59-0.88; P = .001) for OS.

Conclusions and Relevance

In 2 large patient cohorts from 2 different continents, regression was a favorable prognostic factor for patients with stage 1 and 2 melanomas, especially in those with thin and intermediate thickness tumors and those with SSM subtype.

Association between Skin Cancer and Systemic and Ocular Comorbidities in South Korea

Background: In this study, we investigated the associations between various systemic and ocular comorbidities and skin cancer, in a nationwide cohort of South Koreans. Method: We reviewed the data of 1,103,302 individuals in the South Korean National Health Insurance Service-National Sample Cohort database from 2002 to 2015. Of these, 1202 individuals diagnosed with skin cancer from 2004 were included in the study group. The control group was matched in a 1:5 ratio based on propensity scores. Results: The prevalence rates of melanoma and non-melanoma skin cancer increased from 2004 to 2015. Multivariate logistic regression analysis revealed that, among the various systemic conditions, hypertension was significantly associated with skin cancer, while among ocular comorbidities, macular degeneration showed a significant association with skin cancer. Conclusions: This is the first study to demonstrate associations between skin cancer and various systemic and ocular comorbidities. The results suggest that hypertension and macular degeneration may increase the risk of skin cancer development, or vice versa. Further studies are needed to evaluate the causal relationships between these conditions.

Prognostic significance of acral lentiginous histologic type in T1 melanoma

Acral lentiginous melanoma (ALM) is a rare type of cutaneous melanoma with a poor prognosis. It is unclear whether the poor outcome of ALM is due to its inherent disease characteristics or advanced stage at initial diagnosis. To address this question, we retrospectively analyzed the clinicopathologic factors of 828 thin (T1; Breslow thickness ≤1.0 mm) melanomas [129 (15.6%) ALMs and 699 (84.4%) non-ALMs] and their nodal and distance metastases and local recurrence rates and determined their relationship with the disease-specific (DSS), overall (OS), and recurrence-free survivals (RFS) at the pathologic stages T1, T1a, and T1b with a median follow-up time of 84.5 months. With the exception of OS at T1b stage, ALM patients showed significantly lower 5- and 10-year DSS, OS, and RFS rates at every pathologic stage when compared with non-ALM. In multivariable analysis, ALM histologic type, SLN positivity, age, and the use of systemic therapy were detected as independent poor prognostic factors associated with significantly lower survival rates. ALM histologic type was associated with lower DSS and OS rates at T1 and T1a stages and lower RFS rates at T1b stage. SLN positivity was associated with lower DSS, OS, and RFS rates at T1, T1a, and T1b stages. Age was associated with lower OS rates at T1 and T1b stages. Whereas the use of systemic therapy was associated with lower DSS rates at T1a stage and RFS rates at T1b stage. In addition, the ALM group showed significantly older median age patients and higher rates of female sex, Hispanic ethnicity, nevoid cytology, non-brisk tumor-infiltrating lymphocytes, nodal metastasis, and local recurrence at every pathologic stage of thin melanoma. Our findings suggest that ALM is inherently more aggressive than other types of cutaneous melanoma. This information may be useful for prognostic stratification of patients with thin melanomas, especially to help guide the clinical decision-making for SLN biopsy and patients entering clinical trials.

Management of Nail Unit Melanoma

Nail unit melanoma is an uncommon form of melanoma with worse prognosis compared with nonacral cutaneous melanoma. Nail unit melanoma is often diagnosed at a late stage. Clinical and dermoscopic features may suggest a diagnosis of nail unit melanoma, but confirmation requires histologic analysis. Like the clinical diagnosis, histopathologic diagnosis of nail unit melanoma is also difficult. The surgical management of nail unit melanoma has evolved from aggressive amputations to digit-sparing approaches. This article reviews the clinical presentation, diagnosis, and surgical treatment of nail unit melanoma to promote early diagnosis and rational surgery.

BRAF Heterogeneity in Melanoma

OPINION STATEMENT

In the era of molecular targeted therapy, the accurate detection of BRAF mutation in melanoma has become increasingly important. With the advances of molecular analyses and immunohistochemistry, the presence of BRAF mutational heterogeneity in melanoma has been widely recognized. Although most patients with melanoma have a homogeneous BRAF mutation status because the BRAF mutation occurs at an early stage of melanoma development and acts as a driver gene mutation, BRAF mutational heterogeneity does exist, among different tumor sites of a single patient (intertumor heterogeneity) and/or even within a single tumor (intratumor heterogeneity). To summarize the published reports, about 10% of melanoma patients may show intertumorally discordant BRAF status and about 15% of BRAF-mutated melanomas may have intratumor BRAF heterogeneity, although the reported results vary strikingly among the studies and methods used. Considering the BRAF heterogeneity of melanoma, a single biopsy from a single tumor may not be sufficient to uncover the entire BRAF status of a patient. Multiple samples from different sites may be preferable to assess the indication of BRAF/MEK inhibitors, as recommended by the current clinical guidelines. The impact of BRAF heterogeneity on patient survival or the response to treatment with BRAF/MEK inhibitors is an interesting issue, but requires further investigation.

Sentinel lymph node biopsy in acral melanoma: A Korean single-center experience with 107 patients (2006-2018)

BACKGROUND

Sentinel lymph node biopsy (SLNB) of primary cutaneous melanoma as an important staging method has not been popularly undertaken in Korea and only a few studies with small patient numbers have been published.

AIM

We examined the clinical feasibility and overall outcomes of SLNB in acral melanoma (AM) of Korean in Kyungpook National University Hospital (KNUH) over the past 13 years.

METHODS

SLNB in AM patients during 2006-2018 were analyzed retrospectively for sentinel lymph node (SLN) harvesting rate, positivity rate, positivity-relevant overall survival (OS) and disease-free survival (DFS), and its side effects.

RESULTS

A total of 109 AM patients who underwent SLNB were enrolled. Harvested nodes were identified from 107 patients and SLN harvesting rate was 98.2%. The mean Breslow thickness (±standard deviation) was 3.38 ± 3.03 mm, and the proportion of ulcerated melanomas was 64%. Twenty-two (20.6%) had a tumor-positive SLN and, among them, 82% (18/22) underwent immediate complete lymph node dissection (CLND). The metastasis-positive nodal basin after CLND was detected in 16.7% of cases (3/18). Tumor-negative SLN cohorts showed significantly better OS and DFS than tumor-positive ones (P = 0.006 and P < 0.001 for each). Two side effects, one seroma and one lymphocele, were observed without major sequelae.

CONCLUSION

SLNB, crucial management of melanoma, proved its efficacy to predict patients' prognosis and could be performed successfully and safely in Korean AM patients by interdisciplinary cooperation between dermatology and other surgical departments. SLN(-) showed significantly better OS and DFS than SLN(+). Significant risk factors for DFS were Breslow thickness, the presence of ulceration and the presence of SLN metastasis. SLNB should be encouraged in order to stage melanoma accurately and direct the proper management in Korean AM.

Reporting regression in primary cutaneous melanoma. Part 2: prognosis, evaluation and management

The effect of histological regression on patient prognosis for primary cutaneous melanoma is controversial. Some authors hypothesize that regression indicates a robust systemic immune response and may decrease risk of metastasis. Others argue that histological regression calls into question a T0 diagnosis because there may have been an invasive component of the melanoma that is no longer visible but is still active. The literature to date does not suggest that histological regression is associated with increased risk of positive sentinel lymph node status, metastasis or increased risk of mortality. Thus, the presence of histological regression should not change patient staging, evaluation or management. The criteria used for reporting regression have varied dramatically across studies, and standardized reporting is needed to foster evidence-based practices in the future.

Clinicopathological Features and Prognostic Factors of Primary Acral Melanomas in Caucasians

Background: Cutaneous melanomas located on the acral part of extremities (hand and foot melanoma; HFM) comprise a rare group within all melanomas in Caucasians. HFM is associated with a poor prognosis. We aimed to evaluate clinicopathological features, long-term outcomes, and prognostic factors in primary HFM in Caucasians. Methods: Medical records of all consecutive patients treated between 1997 and 2014 were revised. Patients were diagnosed with primary cutaneous melanoma at I-II clinical stage, and sentinel lymph node biopsy was conducted. The analysis was performed to define the clinicopathological factors influencing outcomes in the HFM and subungual cohort. Among 2537 consecutive patients diagnosed with primary cutaneous melanoma, 247 cases of HFM (9.7%) were found, with a median follow-up time of 7.8 years. Results: Median primary tumor Breslow thickness in subungual melanomas and HFMs was 4.0 mm and 3.3 mm, respectively, significantly higher than in the entire population (median 2.2 mm; p < 0.01). In the HFM group, 37.6% of tumors were ulcerated. Metastases to sentinel lymph node (SLN) were found in 28.3% of HFMs. The 10-year overall survival rate in the HFM group and subungual melanomas was 48.1% and 49.3%, respectively, compared to 63.0% in non-HFM melanomas. Conclusions: Our results confirm that patients with HFMs display worse overall survival compared to the entire melanoma population, with male gender and positive SLN biopsy status acting as independent negative prognostic factors.

Narrow-Margin Excision for Invasive Acral Melanoma: Is It Acceptable?

In this retrospective review of 100 patients with primary invasive acral melanoma, we examined whether narrow-margin excision is warranted for acral melanoma. Patients treated with surgical margins recommended by the National Comprehensive Cancer Network (R-group) were compared to those treated with narrow margins (N-group). A total of 65 patients underwent narrow-margin excision. Positive margin status or local recurrence rarely occurred regardless of the excision margins, whereas fatal events frequently occurred, particularly among the patients with T4 melanoma. The mortality rates of N- and R-group with T1–3 melanomas were similar (1.36 and 1.28 per 100 person-years, respectively). However, patients with T4 melanoma treated with narrow-margin excision had a higher mortality rate (11.44 vs. 5.03 per 100 person-years). Kaplan–Meier analyses showed a worse prognosis in the N-group (p = 0.045) but this group had thicker Breslow thickness (4.21 mm vs. 2.03 mm, p = 0.0013). A multivariate analysis showed that Breslow thickness was an independent risk factor, but surgical margin was not a risk factor for melanoma-specific survival or disease-free survival. In conclusion, although we could not find a difference between the narrow-margin excision and recommended-margin excision in this study, we suggest following current recommendations of guidelines. Our study warrants the prospective collection of data on acral melanoma to better define the prognosis of this infrequent type of melanoma.

Acral Lentiginous Melanoma: Do Surgical Approach and Sentinel Lymph Node Biopsy Matter?

Management of acral lentiginous melanoma (ALM) remains controversial. Traditionally, ALM was managed with digit amputation (DA), resulting in significant morbidity, but recent evidence has advocated for digit sparing management. Furthermore, the significance of nodal metastasis for ALM is not well reported. The aims of this study were to determine if surgical approach for primary ALM impacts outcomes and to evaluate the predictive value of nodal status for ALM.

Acral lentiginous melanoma: a single-centre retrospective review of four decades in East-Central Europe

BACKGROUND

Acral lentiginous melanoma (ALM) occurs on the palms, soles and subungual surface and has poor prognosis. It is uncommon in the Caucasian population and has remained unreported in East-Central Europe.

OBJECTIVES

Our aim was to collect data from East-Central Europe by analysing the demographic and clinicopathologic features of patients with ALM and comparing data with the reports in literature.

METHODS

We conducted a single-centre, retrospective review between 1976 and 2016 at one of the largest melanoma referral centres in Hungary.

RESULTS

We identified 176 patients with ALM (3.83%) from 4593 patients with melanoma (mean age: 66.2 years). The tumours were mainly located on the lower extremities (88.63%). The mean Breslow tumour thickness was 3.861 mm, 37.50% of the tumours were thicker than 4.00 mm, and 71.6% exhibited microscopic ulceration. Nearly one-third of the patients underwent sentinel lymph node (SLN) biopsy, and 60.3% of the biopsies were positive for metastasis. The positive SLN status was associated with significantly thick tumours and reduced survival. Patients with ALM had 5- and 10-year overall survival rates of 60.5% and 41.6%, respectively. The mean delay in diagnosis was 18 months after the discovery of skin tumours. In multivariate analyses, age, tumour thickness and distant metastasis were independent risk factors for poor survival (P < 0.001).

CONCLUSIONS

Our study, which is the first single-centre report in East-Central Europe focusing on ALM, confirms that patient and tumour characteristics and prognostic factors are similar with previous literature data involving Caucasians; however, tumour thickness and survival suggest even worse prognosis.

Immunohistochemical BRAF V600E Expression and Intratumor BRAF V600E Heterogeneity in Acral Melanoma: Implication in Melanoma-Specific Survival

Acral melanoma, a distinct form of cutaneous melanoma originating in the glabrous skin of the palms, soles, and nail beds, has a different genetic background from other subtypes of cutaneous melanoma. The roles of oncogenic BRAF mutations of acral melanoma in pathogenesis and patient outcomes have not been fully elucidated. We retrieved a total of 112 patients with primary acral melanoma and checked their BRAF V600E status using immunohistochemical staining of VE1 antibody. Among these cases, 21 acral melanoma samples (18.8%) showed positive BRAF V600E staining, and of those, 11 samples (9.8%) showed a heterogeneous staining pattern, with a mixture of VE1-positive and VE1-negative cells. BRAF V600E positivity was significantly associated with thicker melanoma (p = 0.0015). There was no significant difference in clinicopathological factors between homogeneous and heterogeneous VE1-positive acral melanoma. Both patients with BRAF V600E-positive acral melanoma and those with heterogeneous BRAF V600E had significantly shorter melanoma-specific survival than those with BRAF V600E-negative melanoma in Kaplan–Meier analysis (p = 0.0283 and p = 0.0065, respectively). These findings provide novel insights into the pathobiology of acral melanoma.

Intra- and Inter-Tumor BRAF Heterogeneity in Acral Melanoma: An Immunohistochemical Analysis

The current development of BRAF inhibitors has revolutionized the treatment of unresectable melanoma. As the potential heterogeneity of BRAF mutations in melanoma has been reported, accurate detection of BRAF mutations are important. However, the genetic heterogeneity of acral melanoma-a distinct type of melanoma with a unique genetic background-has not fully been investigated. We conducted a retrospective review of our acral melanoma patients. Of the 196 patients with acral melanoma, we retrieved 31 pairs of primary and matched metastatic melanomas. We immunostained the 31 pairs with VE1, a BRAFV600E-mutation-specific monoclonal antibody. Immunohistochemistry with VE1 showed a high degree of sensitivity and specificity for detecting BRAFV600E mutations compared with the real-time polymerase chain reaction method. A total of nine primary (29.0%) and eight metastatic (25.8%) acral melanomas were positive for VE1. In three patients (9.7%), we observed a discordance of VE1 staining between the primary and metastatic lesions. Of note, VE1 immunohistochemical staining revealed a remarkable degree of intra-tumor genetic heterogeneity in acral melanoma. Our study reveals that VE1 immunostaining is a useful ancillary method for detecting BRAFV600E mutations in acral melanoma and allows for a clear visualization of intra- and inter-tumor BRAF heterogeneity.

The Role and Necessity of Sentinel Lymph Node Biopsy for Invasive Melanoma

Sentinel lymph node biopsy (SLNB) is a widely accepted procedure for melanoma staging and treatment. The development of lymphatic mapping and SLNB, which was first introduced in 1992, has enabled surgeons to detect microscopic nodal metastases and stage-negative regional nodal basins with low morbidity. SLNB has also facilitated the selective application of regional lymph node dissection for patients with microscopic nodal metastases, enabling unnecessary lymph node dissection. In contrast, recent major randomized phase III trials (DeCOG-SLT and MSLT–II trial) compared the clinical benefit of early completion lymph node dissection with observation after detecting microscopic nodal disease. The results of those studies indicated that there was no significant difference in the survival between the two groups, although regional control was superior after early completion lymph node dissection compared to that obtained after observation. Thus, the role and value of early completion lymph node dissection worldwide are currently very limited for patients with microscopic nodal disease. However, the use of SLNB is still controversial. In addition, the recent approval of adjuvant therapy using novel agents, such as anti-programmed death-1 antibodies, and molecular targeted therapeutics may influence the skipping of complete lymph node dissection in patients with micrometastatic nodal disease in a real-world setting. Furthermore, modern neoadjuvant therapy, which is now under investigation, may have the potential to change the surgical procedure used for nodal disease. Herein, we describe the current role and value of SLNB and completion lymph node dissection and discuss the major controversies as well as the favorable future outlook.

Periostin Links Skin Inflammation to Melanoma Progression in Humans and Mice

It is widely accepted that chronic inflammation initiates and promotes carcinogenesis and tumor progression in various cell types. However, this paradigm has not been comprehensively investigated in melanoma. To investigate the effects of chronic inflammation on the progression of melanoma, we established a murine inflammatory skin model and investigated the relationship between skin inflammation and melanoma progression. In a murine model, B16F10 melanoma cells in inflamed skin grew significantly more rapidly than cells in control skin. The stromal expression of periostin was upregulated in inflamed skin, and significantly more CD163⁺ M2 macrophages were recruited to the melanomas in inflamed skin. We then immunohistologically examined the expression of stromal periostin and the infiltration of CD163⁺ M2 macrophages in human acral lentiginous melanomas (n = 94) and analyzed the statistical associations with clinicopathological variables. In human melanomas, high periostin expression and a large number of infiltrated M2 macrophages were significantly correlated with poor prognosis. Furthermore, we confirmed that periostin promotes the proliferation of murine and human melanoma cells in vitro. Our findings indicate that periostin and M2 macrophages play a critical role in melanoma progression and prognosis in both humans and mice, indicating that periostin is a potential target for treating progressive melanoma.

Vertical Growth Phase as a Prognostic Factor for Sentinel Lymph Node Positivity in Thin Melanomas: A Systematic Review and Meta-Analysis

BACKGROUND

The 2010 American Joint Committee on Cancer guidelines recommended consideration of sentinel lymph node biopsy for thin melanoma (Breslow thickness <1.0 mm) with aggressive pathologic features such as ulceration and/or high mitotic rate. The therapeutic benefit of biopsy-based treatment remains controversial. The authors conducted a meta-analysis to estimate the risk and outcomes of sentinel lymph node positivity in thin melanoma, and examined established and potential novel predictors of positivity.

METHODS

Three databases were searched by two independent reviewers for sentinel lymph node positivity in patients with thin melanoma. Study heterogeneity, publication bias, and quality were assessed. Data collected included age, sex, Breslow thickness, mitotic rate, ulceration, regression, Clark level, tumor-infiltrating lymphocytes, and vertical growth phase. Positivity was estimated using a random effects model. Association of positivity and clinicopathologic features was investigated using meta-regression.

RESULTS

Ninety-three studies were identified representing 35,276 patients with thin melanoma who underwent sentinel lymph node biopsy. Of these patients, 952 had a positive sentinel lymph node biopsy, for an event rate of 5.1 percent (95 percent CI, 4.1 to 6.3 percent). Significant associations were identified between positivity and Breslow thickness greater than 0.75 mm but less than 1.0 mm, mitotic rate, ulceration, and Clark level greater than IV. Seven studies reported on vertical growth phase, which was strongly associated with positivity (OR, 4.3; 95 percent CI, 2.5 to 7.7).

CONCLUSIONS

To date, this is the largest meta-analysis to examine predictors of sentinel lymph node biopsy positivity in patients with thin melanoma. Vertical growth phase had a strong association with biopsy positivity, providing support for its inclusion in standardized pathologic reporting.

Metastatic acral lentiginous melanoma in a tertiary referral center in Switzerland: a systematic analysis

Acral lentiginous melanoma (ALM) is a unique histopathological subtype of melanoma with a poorer prognosis than other cutaneous melanomas. This study aims to evaluate the clinicopathological characteristics, metastatic pattern, prognostic factors, response to systemic therapy, and overall survival (OS) of ALM in a White population. This is a retrospective study of patients who were diagnosed and/or treated for ALM at the Department of Dermatology of the University Hospital Zurich, Switzerland, from January 2005 to December 2015. Overall, 172 patients with histologically confirmed ALM were included in the study. In univariate Cox regression, Breslow thickness (P<0.001), age (P=0.003), status of sentinel lymph node (P=0.005), and ulceration (P=0.008) were identified as significant prognostic factors for OS in ALM. In multivariate analysis, only Breslow thickness (P=0.0003) showed statistical significance. The median OS (mOS) was 155.7 months in the entire cohort (n=172) and 11.2 months for stage IV patients (n=36), irrespective of treatment. When first treatment was considered (n=35), mOS for stage IV patients was 8.9, 16.6, 21.7, and 3.7 months, for patients who had received chemotherapy (ChT) (n=17), immunotherapy (n=9), targeted therapy (TT) (n=3), and no therapy (n=6), respectively. The overall response rate was 44% (7/16 patients) to ChT, 100% to TT (3/3), and 25% to ipilimumab (2/8). In our study, Breslow thickness represents the best prognostic factor for OS. In stage IV ALM patients treated with either immunotherapy or TT, there is a trend for extended mOS compared with ChT.

Acral Melanoma: A Patient's Experience and Physician's Commentary

This article, co-authored by a patient diagnosed with acral melanoma, discusses the patient's experience of being diagnosed with and treated with surgery for this disease. The physician discusses the epidemiology, genetics, diagnosis, treatment, and prognosis of acral melanoma. Follow-up care plans are also discussed.

TERT copy gain predicts the outcome of high-dose interferon α-2b therapy in acral melanoma

Background

Asian populations are more likely to develop acral melanoma (AM) than Caucasians. The high-dose interferon (HD-IFN) α-2b regimen is the main adjuvant treatment for AM. TERT encodes the catalytic subunit of telomerase reverse transcriptase, which plays an important role in melanoma. Frequent TERT mutation and increased TERT gene expression have been described in AM. Our study aimed to investigate the status and the clinical significance of TERT copy number in a large cohort of patients with AM and to analyze the relationship between TERT copy number gain and the efficiency of HD-IFN.

Patients and methods

A total of 573 melanoma samples were retrospectively collected and analyzed for TERT copy number via Sanger sequencing. Clinical data of patients were also collected.

Results

TERT copy gain (copy number >2) was detected in 257 of the 573 patients with AM (44.9%). Of the 573 patients, 81 (14.1%) had a high copy gain (copy number >4). Patients with ulceration showed a significantly higher copy gain rate of TERT compared to the patients without ulceration (P=0.028). Patients with a tumor thicker than 4 mm also had a higher copy number rate of TERT than those with <4 mm (P=0.048). Our results showed that the overall survival (OS) was not significantly different between patients with and without TERT copy gain (P=0.890). However, among the 278 patients who received an HD-IFN regimen, Kaplan–Meier survival analysis demonstrated a significant correlation between TERT copy gain and relapse-free survival (RFS) (P=0.008). In addition, multivariate Cox regression assays validated TERT copy gain to be an independent prognostic factor of RFS for patients with AM undergoing HD-IFN therapy (hazard ratio =1.50; P=0.019).

Conclusion

The copy number status of TERT might be a predictor for HD-IFN efficacy, but it is not a prognostic factor of OS in patients with AM.

Surgical Management of Plantar Melanoma: A Retrospective Study in One Center

Cutaneous melanoma is a highly malignant skin tumor, and in China, the planta pedis is a commonly involved site. The sites of plantar melanomas are a challenge to reconstruct after wide excision. Our experience with surgical management of melanomas was based on the 4 different anatomic subunits of the planta pedis. From January 1, 2002 to December 31, 2016, 35 patients who had had plantar melanoma had undergone surgical treatment in our clinic. The tumor locations were as follows: the toe in 6, the ball of the foot in 5, the arch in 15, and the heel in 9. Surgical management involved extended resection of the tumor, repair of defects with skin grafts or flaps, and inguinal lymphadenectomy. The skin flaps included a residual toe flap, an anterograde or retrograde medial plantar flap, and a retrograde sural neurocutaneous vascular flap. Of the 35 cases of flaps and skin grafts, 33 (94.29%) survived, and the wounds had healed by first intention. After a follow-up period of 6 months to 7 years, 24 patients (68.57%) were free of local and systemic disease and 30 patients (85.71%) were ambulatory using shoes, and all the flaps and skin grafts showed a good appearance. The personalized surgical treatments we used for melanoma in the planta pedis resulted in overall satisfactory outcomes and adequate disease clearance, and allowed the patients to resume normal lives. The function of the foot was maintained or restored to the greatest possible degree, and the patients' quality of life improved postoperatively.

Diagnosis and Management of Acral Lentiginous Melanoma

OPINION STATEMENT

Melanoma is one of the most aggressive malignant skin tumors and its incidence has been increasing worldwide in recent decades. Among the four subtypes, acral lentiginous melanoma (ALM) shows the highest incidence in Asian countries, whereas ALM comprises only 1% of all melanomas in white populations. Early clinical diagnosis of ALM is essential, but early ALM lesions are often difficult to diagnose because the pigmentation of the lesions sometimes follows the skin marking of the palms and soles, resulting in an asymmetrical appearance and an irregular border in both ALM and benign melanocytic nevus. To overcome this difficulty, dermoscopy was introduced, and determination of the patterns by this method is essential for accurate clinical diagnosis of ALM. Although recent clinical trials have demonstrated that immune checkpoint inhibitors and BRAF/MEK inhibitors showed significantly improved overall survival of patients with advanced melanoma, ALM may be less susceptible to immune checkpoint inhibitors because of the poor immune response to the tumor. Therefore, strategies for enhancing the immune response to the tumor cells may be required when we apply immune checkpoint inhibitors in advanced ALM. In this context, imiquimod, dacarbazine, or interferon are possible therapies that may enhance the effectiveness of the immune checkpoint inhibitors. In addition to being known to have poor immunogenicity, ALM is also known to have infrequent BRAF mutation. Therefore, the majority of ALM patients may not benefit from therapy with BRAF/MEK inhibitors. However, some ALMs have mutations such as KIT and NRAS mutations, and therefore, targeted therapies may improve the survival of ALM patients in the future.

Prognostic role of histological regression in primary cutaneous melanoma: a systematic review and meta-analysis

The prognostic significance of histological regression in primary melanoma has been debated for many years. We aim to review the evidence to see how histological regression may affect prognosis. A systematic review was performed by searching in MEDLINE, Scopus and the Cochrane Library from 1 January 1966 to 1 August 2015. All studies reporting hazard ratios or data on survival and histological regression were included. Primary random-effects meta-analyses were used to summarize outcome measures. Heterogeneity was assessed using the χ² -test and I² -statistic. To assess the potential bias of small studies we used funnel plots and the Begg and Mazumdar adjusted rank correlation method. Summaries of survival outcomes were measured as hazard ratios or relative risk of death at 5 years according to the presence of histological regression of primary melanoma. In total, 183 articles were reviewed out of 1876 retrieved. Ten studies comprising 8557 patients were included. Patients with histological regression had a lower relative risk of death (0·77, 95% confidence interval 0·61-0·97) than those without. Examination of the funnel plot did not provide evidence of publication bias. The results showed that histological regression is a protective factor for survival.

Prognostic role of the histological subtype of melanoma on the hands and feet in Caucasians

Acral melanoma (AM) is associated with a poor prognosis in part because of delayed diagnosis, but probably also because of other intrinsic characteristics of location. The aim of this study was to review the specific characteristics and outcome of AM in Caucasians. This was a cross-sectional retrospective clinical-pathological study of 274 patients identified with AM in the database of a referral unit in Europe from 1986 to 2010. The mean age of the patients was 56.6 (SD 17.7) years. 269 cases could be histologically classified and included in the study. In all, 222 (82.5%) were located on feet. According to melanoma subtype, 165 (61.3%) were acral lentiginous melanoma (ALM), 84 (31.2%) were superficial spreading melanoma (SSM), and 20 (7.5%) were nodular melanoma (NM). SSM patients were characterized by female predominance (77.4%), younger age, and classic melanoma-risk phenotype (fair skin and multiple nevi). Among the 198 invasive cases with a mean follow-up of 56.2 months, the mean (SD) Breslow's thickness was 3.1 (3.6) mm, being 1.4 (1.4) mm in SSM, 3.5 (4.1) mm in ALM and 4.9 (2.9) mm in NM (P<0.001). Ulceration was present in 33.3%, 2.9% in SSM, 38.6% in ALM, and 76.9% in NM (P<0.001). A total of 29.3% relapsed (7.3% of SSM, 35% of ALM and 55% of NM) and 24.2% died because of AM. In multivariate analysis, age at diagnosis, Breslow, and histopathological subtype were independent prognostic factors for both disease-free and AM-specific survival. The ALM and NM subtypes presented poorer outcome after weighting Breslow and age (P=0.02). Histological subtype of AM could have an impact on biological behavior, ALM and NM subtypes presenting a poorer prognosis after adjusting for age and Breslow's thickness.

Acral lentiginous melanoma versus other melanoma: A single-center analysis in Japan

We summarize herein our 14-year experience of conventional treatment outcomes before the era of molecular-targeted therapy and immunotherapy. Specifically, we conducted a retrospective review of our 252 patients with primary cutaneous melanoma (acral lentiginous melanoma [ALM], n = 121; non-acral lentiginous melanoma [non-ALM], n = 131), and compared the prognostic factors between ALM and non-ALM. Melanoma-specific survival and disease-free survival were estimated using the Kaplan-Meier method. Regarding the results, all patients were Japanese (106 male and 146 female), with a mean age of 60.1 years. Among ALM patients, age was elder and primary tumor size was larger than non-ALM. As for tumor thickness, in situ lesions were more frequently observed in ALM. There was no significant difference in the distribution of tumor thickness between the two groups when excluding the in situ lesions. For treatment of the primary melanoma, 248 patients (98.4%) had undergone curative surgical excision and 120 patients with more than 1 mm or ulcerated melanoma had undergone sentinel lymph node biopsy. Patients with systemic metastasis primarily underwent dacarbazine-based chemotherapy. The Kaplan-Meier survival curves revealed no significant difference in melanoma-specific survival and disease-free survival between those with ALM and non-ALM. The results also showed that both ALM and non-ALM, when they initially metastasize, first affect the regional lymph nodes. Incisional biopsy was not an adverse prognostic factor. These results suggest that ALM does not differ in its biological behavior from non-ALM, so we can consider ALM as being equivalent to non-ALM. The initial treatment for ALM and non-ALM can involve the same strategy.

Regression in cutaneous melanoma: a comprehensive review from diagnosis to prognosis

Histological regression in primary cutaneous melanoma occurs in 10-35% of cases. Although a large body of literature exists to suggest that histological regression serves very little purpose in predicting biologic behaviour with melanoma, recognizing the presence of regression at clinical and histological ground may still retain some value in grading melanoma aggressiveness. In the current review, a comprehensive overview of the main aspects of regression will be provided. Histologically, many classifications have been reported so far, but all of them only agreed on the presence of an infiltrate of lymphocytes admixed with pigment-laden macrophages underlying an atrophic epidermis with flattened rete ridges. Upon dermoscopy, regression is also named Blue White Scar-like areas and could be variably admixed with granularity or peppering. Almost fully regressed lesions represent a main diagnostic issue in dermoscopy, and thus, confocal microscopy can be of help to identify whether the tumour is melanocytic or not. The clinical utility of regression as a prognostic factor has been challenged recently. Nowadays, evidences showed that it is less likely associated to SLN metastases.

Melanoma of the Foot

Melanoma is a rare form of skin cancer that is responsible for most skin cancer deaths globally. Tumors arising on the foot continue to be a particular challenge. Patients present later and lesions are frequently misdiagnosed, leading to more advanced disease with an overall poorer prognosis then melanoma elsewhere. In order to improve early recognition, this article reviews the clinical features of the disease along with published algorithms. Emerging assessment techniques such as dermoscopy are also discussed as tools to improve clinical decision making. Contemporary drug therapies in the treatment of advanced disease are also discussed.

Cutaneous angiosarcoma of the head and face: a single-center analysis of treatment outcomes in 43 patients in Japan

PURPOSE

For a better understanding of angiosarcoma, we summarized our 30-year experience of conventional treatment outcomes before the era of molecular-targeted therapy.

METHODS

We conducted a retrospective review of our 43 patients with cutaneous angiosarcoma of the head and face, and investigated the prognostic factors including the treatment strategy. Disease-specific survival (DSS) and event-free survival (EFS) were estimated using the Kaplan-Meier method, together with multivariate analyses using the Cox proportional hazard regression model.

RESULTS

All patients were Japanese (25 males and 18 females), with a mean age of 72.1. For the initial treatment of the primary lesion, 34 patients underwent radiotherapy with or without taxanes (docetaxel and/or paclitaxel); only 6 patients underwent surgical excision. As the systemic adjuvant therapy, 19 patients were treated with taxanes and 15 with interleukin-2. Interestingly, patients who underwent the continued chemotherapy with taxanes had significantly prolonged DSS (5-year DSS, 57.0 vs. 19.6 %; median survival, 62.2 vs. 17.7 months; P = 0.0049) and EFS (5-year EFS, 34.9 vs. 5.6 %; median survival, 46.7 vs. 12.4 months; P = 0.0024) than the others. The continuous use of taxanes was also a prognostic factor in multivariate analyses. Neither radiotherapy nor surgical excision significantly influenced the patients' outcome. Among five patients who survived more than 5 years, three underwent surgical excision of the primary tumor or lung metastasis.

CONCLUSIONS

Our results suggest that continued chemotherapy with taxanes is important for patient survival.

Clinical utilities and biological characteristics of melanoma sentinel lymph nodes

An estimated 73870 people will be diagnosed with melanoma in the United States in 2015, resulting in 9940 deaths. The majority of patients with cutaneous melanomas are cured with wide local excision. However, current evidence supports the use of sentinel lymph node biopsy (SLNB) given the 15%-20% of patients who harbor regional node metastasis. More importantly, the presence or absence of nodal micrometastases has been found to be the most important prognostic factor in early-stage melanoma, particularly in intermediate thickness melanoma. This review examines the development of SLNB for melanoma as a means to determine a patient’s nodal status, the efficacy of SLNB in patients with melanoma, and the biology of melanoma metastatic to sentinel lymph nodes. Prospective randomized trials have guided the development of practice guidelines for use of SLNB for melanoma and have shown the prognostic value of SLNB. Given the rapidly advancing molecular and surgical technologies, the technical aspects of diagnosis, identification, and management of regional lymph nodes in melanoma continues to evolve and to improve. Additionally, there is ongoing research examining both the role of SLNB for specific clinical scenarios and the ways to identify patients who may benefit from completion lymphadenectomy for a positive SLN. Until further data provides sufficient evidence to alter national consensus-based guidelines, SLNB with completion lymphadenectomy remains the standard of care for clinically node-negative patients found to have a positive SLN.

Prognostic significance of forkhead box M1 (FoxM1) expression and antitumour effect of FoxM1 inhibition in melanoma

AIMS

Forkhead box M1 (FoxM1) is a transcription factor that regulates cell-cycle progression and tumour progression, but limited information is available regarding its clinical significance in melanoma. The aim of this study was to investigate the potency of FoxM1 as a therapeutic target in melanoma.

METHODS AND RESULTS

We investigated 60 melanoma clinical samples and a melanoma WM266-4 cell line using immunohistochemical staining and molecular biological approaches. Patients with a FoxM1-overexpressing melanoma had significantly shorter survival [both for melanoma-specific survival (MSS) and disease-free survival (DFS)] than the other patients (P < 0.001, respectively). The FoxM1 overexpression was also an adverse prognostic factor for both MSS and DFS on the Cox multivariate analyses [hazard ratio (HR): 3.96, 95% confidence interval (CI): 1.12-14.27, P = 0.032; HR: 3.21, 95% CI: 1.08-9.67, P = 0.037, respectively). FoxM1 inhibition using siRNA and an inhibitor (thiostrepton) each suppressed the cell proliferation of the melanoma cell line. Furthermore, FoxM1 inhibition improved chemosensitivity to dacarbazine, whereas it reduced cell migration and invasion. These results suggest that FoxM1 plays important roles in tumour progression and the chemoresistance of melanoma.

CONCLUSION

We have shown the prognostic impact of FoxM1 on melanoma patients. FoxM1 inhibition may be a potential therapeutic option for advanced melanoma.

Atypical dermoscopic presentation of an acral congenital melanocytic nevus in an adult: parallel ridge pattern and its histologic correlation

Acral melanoma is the most frequent subtype in the Asian and Mexican mestizo populations. Dermoscopy is a noninvasive diagnostic technique that helps the differential diagnosis of pigmented skin lesions on acral volar skin.

We, herein, present a case of acral congenital melanocytic nevus with a parallel ridge dermoscopic pattern. Since the parallel ridge pattern in a melanocytic lesion of the acral skin is classically ascribed to melanoma, the present case can be definitely labeled as “atypical” and worth of being elucidated in its histopathological correlates.

Hyperkeratotic acral melanoma mimicking a common wart

Acral melanoma is a great pretender; anything but i nfrequently, it adopts clinical faces, simulating skin conditions that make the healthcare provider diagnose it as a benign disease of the palms, soles, and ungual regions. We present a case of a hyperkeratotic acral melanoma that has been misdiagnosed and that has led to an amputation of the thumb.