Acral Lentiginous Melanoma: Incidence and Survival in the United States, 2006-2015, an Analysis of the SEER Registry

A Review of Melanoma Subtypes: Genetic and Treatment Considerations

Melanoma affects over one million people in the United States. This review explores genetic mutations and markers of all seven subtypes. Current treatment options and prognosis of each subtype are also discussed. For lentigo maligna, spitzoid, and nodular subtypes, BRAF was the most common mutation reported. For superficial spreading, TP53 was the most common. Acral lentiginous demonstrated CCDN1 and desmoplastic NF1 most frequently. No mutations have been identified in the nevoid subtype. Nodular melanoma is the deadliest subtype. Evidence suggests that the subtypes differ in regard to genetic markers/mutations, treatment and prognosis. Therefore, subtype should be considered when treating a melanoma patient.

Trends in Melanoma Incidence, Prevalence, Stage at Diagnosis, and Survival: An Analysis of the United States Cancer Statistics (USCS) Database

Background and objectives Melanoma, a major skin cancer, has seen varying trends in incidence, prevalence, stage at diagnosis, and survival. This study examines these trends using the United States Cancer Statistics (USCS) database, covering the period from 1999 to 2021. Methods We extracted data from the USCS database, which integrates the National Cancer Institute's (NCI) Surveillance, Epidemiology, and End Results (SEER) program and the Centers for Disease Control and Prevention's (CDC) National Program of Cancer Registries (NPCR). The analysis included new melanoma cases, prevalence estimates (using a 20-year limited duration), stage at diagnosis, and five-year relative survival rates. Incidence rates were adjusted for age using the 2000 United States standard population. Descriptive and trend analyses were performed using IBM SPSS Statistics software, version 29 (IBM Corp., Armonk, NY).  Results The analysis of melanoma trends from 1999 to 2021 reveals a significant increase in the annual age-adjusted incidence rate, rising from 15.1 per 100,000 (95% CI: 14.9- 15.2) in 1999 to 23.0 per 100,000 (95% CI: 22.8- 23.1) in 2021. This upward trend is consistent across gender and racial/ethnic groups. The prevalence of melanoma over a 20-year period was 0.279 (95% CI: 0.276-0.282), with males showing a higher prevalence (0.302, 95% CI: 0.298-0.306) compared to females (0.256, 95% CI: 0.252-0.260). The distribution of melanoma stage at diagnosis indicated that 77% of cases were localized (95% CI: 76.5-77.5%), 9.5% regional (95% CI: 9.2-9.8%), 4.7% distant (95% CI: 4.4-5.0%), and 8.8% unstaged (95% CI: 8.5-9.1%). Survival analysis showed a five-year relative survival rate of 99.4% (95% CI: 99.2-99.6%) for localized melanoma and 35.6% (95% CI: 33.7-37.6%) for distant melanoma, highlighting significant disparities in survival based on stage at diagnosis. Conclusions The study highlights a rising incidence of melanoma and emphasizes the critical role of early detection in improving survival outcomes. The findings underscore the effectiveness of early diagnosis and the necessity for ongoing efforts to improve melanoma outcomes across diverse populations.

A Narrative Review of the Evolution of Diagnostic Techniques and Treatment Strategies for Acral Lentiginous Melanoma

Acral melanoma (AM) is a subtype of cutaneous melanoma located on the palms, soles, and nails. The pathogenesis of AM involves mechanical stimulation and characteristic tumor-promoting mutations, such as those in the KIT proto-oncogene. Dermoscopy is useful for diagnosing AM, which is characterized by parallel ridge patterns and irregular diffuse pigmentation. Although histopathological confirmation is the gold standard for diagnosing AM, lesions showing minimal histopathological changes should be considered early-stage AM if they clinically resemble it. Recently, immunohistochemical staining of preferentially expressed antigen in melanoma has been recognized as a useful method to distinguish benign from malignant melanocytic tumors. Research reveals that AM is associated with an immunosuppressive microenvironment characterized by increased numbers of M2 macrophages and regulatory T cells, alongside a decreased number of tumor-infiltrating lymphocytes. Mohs micrographic surgery or digit-sparing wide local excision has been explored to improve quality of life and replace wide local excision or proximal amputation. AM has a worse prognosis than other subtypes, even in the early stages, indicating its inherent aggressiveness.

Unveiling Melanoma: A Deep Dive into Disparities at a Latin-American Cancer Institute

INTRODUCTION

The worldwide incidence of melanoma has increased in the last 40 years. Our aim was to describe the clinic-pathological characteristics and outcomes of three cohorts of patients diagnosed with melanoma in a Latin-American cancer institute during the last 20 years.

METHODS

We evaluated three retrospective patient cohorts diagnosed with melanoma at Instituto Nacional de Enfermedades Neoplasicas (INEN), a public hospital in Lima, Peru, for the years 2005-2006, 2010-2011, and 2017-2018. Survival rate differences were assessed using the Log-rank test.

RESULTS

Overall, 584 patients were included (only trunk and extremities); 51% were male, the mean age was 61 (3-97) years, and 48% of patients resided in rural areas. The mean time to diagnosis was 22.6 months, and the mean Breslow thickness was 7.4 mm (T4). Lower extremity was the most common location (72%). A majority of the patients (55%) had metastases at the time of presentation, with 36% in stage III and 19% in stage IV. Cohorts were distributed as 2005-2006 (n = 171), 2010-2011 (n = 223), and 2017-2018 (n = 190). No immunotherapy was used. Cohort C exhibited the most significant increase in stage IV diagnoses (12.3%, 15.7%, 28.4%, respectively; p < 0.01). The median overall survival rates at the three-year follow-up demonstrated a decline over the years for stages II (97%, 98%, 57%, respectively; p < 0.05) and III (66%, 77%, 37%; p < 0.01).

CONCLUSIONS

There has been a worsening in the incidence of late-stage metastatic melanoma in Peru throughout the years, coupled with a significant decline in overall survival rates. This is underscored by the fact that half of the population lives in regions devoid of oncological access.

Acral Melanoma Incidence and Survival Trends in 1990-2020: A Nationwide, Population-based Study

Acral melanoma is a clinical subtype of melanoma with high mortality, on which research is limited in scope. This study aimed to assess incidence trends and melanoma-specific survival rates for acral melanoma in the Swedish population from 1990 to 2020.This cross-sectional study included patients with an acral melanoma diagnosis from 1990 to 2020 from the nationwide, population-based Swedish Melanoma Registry. Analyses on acral melanoma melanoma-specific survival rates were adjusted for age, sex, histopathological subtype, and tumour thickness. Clinicopathological features and melanoma-specific survival rates were compared between diagnostic periods: 1990-1999, 2000-2009, and 2010-2020, respectively. Changes in standardized incidence rates in 1996-2020 were evaluated separately for males and females. In total, 1,000 acral melanomas in 999 patients were included in the study. No significant yearly change in standardized incidence rates for either males or females was observed, even though the absolute number of cases increased. Factors such as male sex, age ≥ 70 years, and Breslow thickness > 1.0 were independently linked to lower melanoma-specific survival. The 5-year melanoma-specific survival across the studied period ranged from 75.8% to 77.9% for females, and from 62.4% to 71.7% for males.

Establishment of a CD8+ T cells-related prognostic risk model for acral melanoma based on single-cell and bulk RNA sequencing

BACKGROUND

CD8+ T cells have been recognized as crucial factors in the prognosis of melanoma. However, there is currently a lack of gene markers that accurately describe their characteristics and functions in acral melanoma (AM), which hinders the development of personalized medicine.

METHODS

Firstly, we explored the composition differences of immune cells in AM using single-cell RNA sequencing (scRNA-seq) data and comprehensively characterized the immune microenvironment of AM in terms of composition, developmental differentiation, function, and cell communication. Subsequently, we constructed and validated a prognostic risk scoring model based on differentially expressed genes (DEGs) of CD8+ T cells using the TCGA-SKCM cohort through Lasso-Cox method. Lastly, immunofluorescence staining was performed to validate the expression of four genes (ISG20, CCL4, LPAR6, DDIT3) in AM and healthy skin tissues as included in the prognostic model.

RESULTS

The scRNA-seq data revealed that memory CD8+ T cells accounted for the highest proportion in the immune microenvironment of AM, reaching 70.5%. Cell-cell communication analysis showed extensive communication relationships among effector CD8+ T cells. Subsequently, we constructed a prognostic scoring model based on DEGs derived from CD8+ T cell sources. Four CD8+ T cell-related genes were included in the construction and validation of the prognostic model. Additionally, immunofluorescence results demonstrated that ISG20 and CCL4 were downregulated, while LPAR6 and DDIT3 were upregulated in AM tissues compared to normal skin tissues.

CONCLUSION

Identifying biomarkers based on the expression levels of CD8+ T cell-related genes may be an effective approach for establishing prognostic models in AM patients. The independently prognostic risk evaluation model we constructed provides new insights and theoretical support for immunotherapy in AM.

Receptor tyrosine kinase inhibition leads to regression of acral melanoma by targeting the tumor microenvironment

Acral melanoma (AM) is an aggressive melanoma variant that arises from palmar, plantar, and nail unit melanocytes. Compared to non-acral cutaneous melanoma (CM), AM is biologically distinct, has an equal incidence across genetic ancestries, typically presents in advanced stage disease, is less responsive to therapy, and has an overall worse prognosis. Independent analysis of published genomic and transcriptomic sequencing identified that receptor tyrosine kinase (RTK) ligands and adapter proteins are frequently amplified, translocated, and/or overexpressed in AM. To target these unique genetic changes, a zebrafish acral melanoma model was exposed to a panel of narrow and broad spectrum multi-RTK inhibitors, revealing that dual FGFR/VEGFR inhibitors decrease acral-analogous melanocyte proliferation and migration. The potent pan-FGFR/VEGFR inhibitor, Lenvatinib, uniformly induces tumor regression in AM patient-derived xenograft (PDX) tumors but only slows tumor growth in CM models. Unlike other multi-RTK inhibitors, Lenvatinib is not directly cytotoxic to dissociated AM PDX tumor cells and instead disrupts tumor architecture and vascular networks. Considering the great difficulty in establishing AM cell culture lines, these findings suggest that AM may be more sensitive to microenvironment perturbations than CM. In conclusion, dual FGFR/VEGFR inhibition may be a viable therapeutic strategy that targets the unique biology of AM.

Clinical characteristics, survival analysis and influencing factors of distant metastasis in patients with acromelanomas: A retrospective study

The prognosis of acromelanomas (AM) is worse. The objective of this study was to investigate the clinical features of distant metastasis of AM and the factors affecting the survival and prognosis of patients. In this study, a retrospective study was conducted to select 154 AM patients admitted to Nanjing Pukou People's Hospital from January 2018 to April 2021 for clinical research. The clinical characteristics of distant metastasis were statistically analyzed, and the survival curve was drawn with 5-year follow-up outcomes. The median survival time of the patients was calculated, and the clinicopathological features and peripheral blood laboratory indexes of the surviving and dead patients were analyzed. Logistic regression model was used to analyze the risk factors affecting the prognosis of AM patients. In this study, 154 patients with AM were treated, including 88 males and 76 females, aged from 27 to 79 years old, with an average age of (59.3 ± 11.7) years old. Among them, 90 cases had distant metastasis. The main metastatic sites were lung (47.78%) and lymph nodes (42.22%). Among them, single site metastasis accounted for 41.11% and multiple site metastasis 58.89%. 89 cases survived and 65 cases died. The survival time was 22 months to 60 months, and the median survival time was 48.0 months. The Breslow thickness, stage at diagnosis, distant metastasis, site of metastasis and ulceration were compared between the survival group and the death group (P < .05). serum lactate dehydrogenase (LDH), neutrophil-to-lymphocyte ratio (NLR) and lymphocyte monocyte ratio (LMR) were compared between the survival group and the death group (P < .05). The results of Logistic regression model showed that LDH ≥ 281 U/L, NLR ≥ 2.96, LMR ≤ 3.57, newly diagnosed stage > stage II, distant metastasis, multiple site metastasis and tumor ulcer were independent risk factors for poor prognosis of AM patients (P < .05). Patients with AM had a higher proportion of distant metastasis, mainly lung and lymph node metastasis. Increased LDH, increased NLR, decreased LMR, higher initial stage, distant metastasis, multiple site metastasis, and combined tumor ulcer were closely related to the poor prognosis of patients after surgery.

Pattern Analysis of Benign and Malignant Atypical Melanocytic Skin Lesions of Palms and Soles: Variations of Dermoscopic Features According to Anatomic Site and Personal Experience

Background: The differential diagnosis of atypical melanocytic skin lesions localized on palms and soles represents a diagnostic challenge: indeed, this spectrum encompasses atypical nevi (AN) and early-stage melanomas (EN) displaying overlapping clinical and dermoscopic features. This often generates unnecessary excisions or delayed diagnosis. Investigations to date were mostly carried out in specific populations, focusing either on acrolentiginous melanomas or morphologically typical acquired nevi. Aims: To investigate the dermoscopic features of atypical melanocytic palmoplantar skin lesions (aMPPLs) as evaluated by variously skilled dermatologists and assess their concordance; to investigate the variations in dermoscopic appearance according to precise location on palms and soles; to detect the features with the strongest association with malignancy/benignity in each specific site. Methods: A dataset of 471 aMPPLs-excised in the suspect of malignancy-was collected from 10 European Centers, including a standardized dermoscopic picture (17×) and lesion/patient metadata. An anatomical classification into 17 subareas was considered, along with an anatomo-functional classification considering pressure/friction, (4 macroareas). A total of 156 participants (95 with less than 5 years of experience in dermoscopy and 61 with ≥than 5 years) from 17 countries performed a blinded tele-dermoscopic pattern analysis over 20 cases through a specifically realized web platform. Results: A total of 37,440 dermoscopic evaluations were obtained over 94 (20%) EM and 377 (80%) AN. The areas with the highest density of EM compared to AN were the heel (40.3% EM/aMPPLs) of the sole and the "fingers area" (33%EM/aMPPLs) of the palm, both characterized by intense/chronic traumatism/friction. Globally, the recognition rates of 12 dermoscopic patterns were non statistically different between 95 dermatology residents and 61 specialists: aMPPLs in the plantar arch appeared to be the most "difficult" to diagnose, the parallel ridge pattern was poorly recognized and irregular/regular fibrillar patterns often misinterpreted. Regarding the aMPPL of the "heel area", the parallel furrow pattern (p = 0.014) and lattice-like pattern (p = 0.001) significantly discriminated benign cases, while asymmetry of colors (p = 0.002) and regression structures (p = 0.025) malignant ones. In aMPPLs of the "plantar arch", the lattice-like pattern (p = 0.012) was significant for benignity and asymmetry of structures, asymmetry of colors, regression structures, or blue-white veil for malignancy. In palmar lesions, no data were significant in the discrimination between malignant and benign aMPPLs. Conclusions: This study highlights that (i) the pattern analysis of aMPPLs is challenging for both experienced and novice dermoscopists; (ii) the histological distribution varies according to the anatomo-functional classification; and (iii) different dermoscopic patterns are able to discriminate malignant from benign aMPPLs within specific plantar and palmar areas.

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.

Baseline Serum neutrophil-to-lymphocyte ratio in acral melanoma compared with nonacral melanoma and its prognostic significance

BACKGROUND

Acral lentiginous melanoma (ALM), a cutaneous melanoma subtype, exhibits a poorer prognosis than nonacral cutaneous melanoma (NACM). The neutrophil-to-lymphocyte ratio (NLR) is emerging as a prognostic indicator across diverse cancers.

OBJECTIVE

We explored the baseline NLR disparities between ALM and NACM, and the NLR's prognostic significance in patients with ALM.

METHODS

We reviewed records of patients with ALM and NACM diagnosed between 1997 and 2022, analyzing medical data.

RESULTS

Among 327 and 159 patients with ALM and NACM, respectively, baseline NLR varied based on distinct clinicopathologic factors between ALM and NACM. In stage 3 to 4 melanomas, the median NLR for ALM (2.18; IQR, 1.70-3.08) significantly surpassed NACM (1.74; IQR, 1.33-2.53) (P = .029). In patients with ALM, high NLR (hazard ratio, 1.64; 95% CI, 1.02-2.66; P = .043) was independently correlated with poor progression-free survival when adjusting for ulceration, Breslow thickness of ≥2 mm, and nodal invasion.

LIMITATIONS

Single-center, retrospective design.

CONCLUSION

Advanced-stage ALM exhibited a significantly higher baseline NLR compared with that of NACM. Evaluating baseline NLR could provide valuable prognostic insights for patients with ALM.

Acral Lentiginous Melanoma: A Clinicoprognostic Study of 149 Cases at a Single Institution

OBJECTIVE

The objective of this study is to investigate the epidemiological features, clinical characteristics, and pathological characteristics of acral lentiginous melanoma (ALM) and identify prognostic factors.

METHODS

A total of 149 patients diagnosed with ALM between August 2008 and December 2019 at the National Cancer Center (NCC) of China were retrospectively analyzed. Follow-up data on patient survival status were collected. Survival curves were generated using the Kaplan-Meier method, and statistical significance was assessed using the log-rank test. Additionally, a Cox proportional hazards model was constructed to identify prognostic factors.

RESULTS

All patients included in this study were of Chinese ethnicity, with an average age of 52.4 ± 14.8 years (range, 15-80 years) at the time of diagnosis. No gender predilection or genetic susceptibility was observed. The plantar region was the most frequently affected site among primary lesions. Notably, only 17 (11.4%) patients reported a history of trauma. Statistical analysis revealed that a lesion duration of ≤2.5 years, Breslow thickness >4.0 mm, high mitotic rate (>6 mm-2), presence of vascular invasion, and regional lymph node metastasis were identified as independent prognostic factors.

CONCLUSION

Our findings indicate that a lesion duration of ≤2.5 years, Breslow thickness >4.0 mm, high mitotic rate (>6 mm-2), presence of vascular invasion, and regional lymph node metastasis are significantly associated with a poorer prognosis for patients with ALM.

Multidisciplinary approach and treatment of acral and mucosal melanoma

Acral and mucosal melanoma are uncommon variants of melanoma. Acral melanoma has an age-adjusted incidence of approximately 1.8 cases per million individuals per year, accounting for about 2% to 3% of all melanoma cases. On the other hand, mucosal melanoma, with an incidence of 2.2 cases per million per year, makes up around 1.3% of all melanoma cases. These melanomas, in addition to being biologically and clinically distinct from cutaneous melanoma, share certain clinical and pathologic characteristics. These include a more aggressive nature and a less favorable prognosis. Furthermore, they exhibit a different mutational pattern, with KIT mutations being more prevalent in acral and mucosal melanomas. This divergence in mutational patterns may partially account for the relatively poorer prognosis, particularly to immune checkpoint inhibitors. This review explores various aspects of acral and mucosal melanoma, including their clinical presentation, pathologic features, mutational profiles, current therapeutic approaches, outcomes associated with systemic therapy, and potential strategies to address resistance to existing treatments.

A European Multicentric Investigation of Atypical Melanocytic Skin Lesions of Palms and Soles: The iDScore-PalmoPlantar Database

Background: The differential diagnosis of atypical melanocytic palmoplantar skin lesions (aMPLs) represents a diagnostic challenge, including atypical nevi (AN) and early melanomas (MMs) that display overlapping clinical and dermoscopic features. We aimed to set up a multicentric dataset of aMPL dermoscopic cases paired with multiple anamnestic risk factors and demographic and morphologic data. Methods: Each aMPL case was paired with a dermoscopic and clinical picture and a series of lesion-related data (maximum diameter value; location on the palm/sole in 17 areas; histologic diagnosis; and patient-related data (age, sex, family history of melanoma/sunburns, phototype, pheomelanin, eye/hair color, multiple/dysplastic body nevi, and traumatism on palms/soles). Results: A total of 542 aMPL cases-113 MM and 429 AN-were collected from 195 males and 347 females. No sex prevalence was found for melanomas, while women were found to have relatively more nevi. Melanomas were prevalent on the heel, plantar arch, and fingers in patients aged 65.3 on average, with an average diameter of 17 mm. Atypical nevi were prevalent on the plantar arch and palmar area of patients aged 41.33 on average, with an average diameter of 7 mm. Conclusions: Keeping in mind the risk profile of an aMPL patient can help obtain a timely differentiation between malignant/benign cases, thus avoiding delayed and inappropriate excision, respectively, with the latter often causing discomfort/dysfunctional scarring, especially at acral sites.

Management of acral lentiginous melanoma: current updates and future directions

Acral lentiginous melanoma is a rare subtype of melanoma generally associated with poor outcomes, even when diagnosed at an early stage. The tumor genetic profile remains poorly understood, but it is known to have a suppressed immune environment compared to that of non-acral cutaneous melanomas, which limits therapy options. There is significant attention on the development of novel therapeutic approaches, although studies are limited due to disease rarity. For local disease, wide local excision remains the standard of care. Due to frequent under-staging on preoperative biopsy, wider margins and routine sentinel lymph node biopsy may be considered if morbidity would not be increased. For advanced disease, anti-PD1 monotherapy or combination therapy with anti-PD1 and anti-CTLA4 agents have been used as first-line treatment modalities. Anti-PD1 and anti-CTLA4 combination therapies have been shown to be particularly beneficial for patients with BRAF-mutant acral lentiginous melanoma. Other systemic combination regimens and targeted therapy options may be considered, although large studies with consistent results are lacking. Regional and intralesional therapies have shown promise for cutaneous melanomas, but studies generally have not reported results for specific histologic subtypes, especially for acral melanoma. Overall, the unique histologic and genetic characteristics of acral lentiginous melanoma make therapy options significantly more challenging. Furthermore, studies are limited, and data reporting has been inconsistent. However, more prospective studies are emerging, and alternative therapy pathways specific to acral lentiginous melanoma are being investigated. As further evidence is discovered, reliable treatment guidelines may be developed.

Prevalence of subungual melanoma in patients with cutaneous malignant melanoma: A systematic review and meta-analysis

BACKGROUND

Subungual melanoma (SUM) is a rare type of cutaneous malignant melanoma (CMM) associated with poor prognosis, while data regarding its prevalence are scarce.

OBJECTIVES

We sought to provide a comprehensive systematic review and meta-analysis of the prevalence rates of SUM among all types of CMM, considering certain demographic and clinical characteristics.

METHODS

The MEDLINE electronic database was searched systematically to identify eligible studies providing prevalence rate estimates of SUM in patients with CMM. Included studies were further analysed to estimate the relative prevalences of SUM according to study design, study years, geographical region and sex distribution.

RESULTS

Twenty-eight studies met the inclusion criteria. The overall SUM prevalence was 1.9% (95% CI [1.5%-2.3%]). The prevalence of SUM did not differ significantly between population- and hospital-based studies and remained stable over time. However, it was found to be significantly higher in Asians compared to patients of other geographical regions as well as in studies with more men than women compared to those with female preponderance (p < 0.001).

CONCLUSIONS

In all, the overall SUM prevalence among all subtypes of CMM was estimated at 1.9%, without significant changes over time, and was found to exhibit significant variability between subgroups of different geographical regions.

Analyzing County-level Social Vulnerabilities of Head and Neck Melanomas in the United States

OBJECTIVES

Studies addressing social determinants of health (SDH) in head-neck melanomas (HNM) have only assessed incidence with increasing socioeconomic status. None have investigated a wider scope of SDH or their summed influence on affecting HNM prognosis and follow-up care.

METHODS

This retrospective cohort study analyzed 374,138 HNM in adults from 1975 to 2017 from the NCI-Surveillance, Epidemiology, and End Results Program (NCI-SEER) database. Utilizing the NCI-SEER database, Social Vulnerability Index (SVI) scores were matched to county of residence upon diagnosis. Univariate linear regressions were performed on length of care (months of follow-up/surveyed) and prognosis (months survival) across various SDH/SVI scores of socioeconomic status, minority and language status, household composition, housing and transportation, and their total composite.

RESULTS

With increasing overall SVI score, which indicates increasing social vulnerability, months of follow-up showed significant decreases ranging from 0.04% to 27.63% compared with the lowest vulnerability groups, with the highest differences in nodular melanomas and the lowest with malignant melanomas in giant pigmented nevi. Similarly, months survival significant decreases ranged from 0.19% to 39.84% compared with the lowest SVI scores, with the highest difference in epithelioid cell melanomas and the lowest in amelanotic melanoma. Comprising this overall score trend, decreases with socioeconomic status, minority-language status, household composition, and housing-transportation contributed differentially per histology subtype.

CONCLUSIONS

Our data highlight significant negative trends in HNM prognosis and care with higher total social vulnerability while showing which SDH-themes quantifiably contribute more to these differences.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:185-190, 2024.

Comparison of full-thickness skin graft and punch grafting in the reconstruction of plantar defects

Acral melanoma commonly occurs on weight-bearing areas of the sole. Reconstruction of such areas presents a surgical challenge due to limited availability and mobility of local skin. Thus, we aimed to compare the scar outcome of full-thickness skin graft (FTSG) and punch grafting in the reconstruction of plantar defects after melanoma surgery. We retrospectively reviewed six patients who underwent both FTSG for nonweight-bearing areas and punch grafting for weight-bearing areas. We compared results of FTSG and punch grafting within the same patient. Photos of completely healed scars were graded using the Stony Brook Scar Evaluation Scale (SBSES). The averages of the FTSG scores and the punch graft scores, as measured by the SBSES, were statistically compared. Punch grafting yielded a better outcome than FTSG, according to the SBSES. The average of the punch grafting scars was 4.67, which was significantly greater (p = 0.004) than that of FTSG scar scores at 1.83. For weight-bearing areas, punch grafting should be considered as the first option of reconstruction, with FTSG as a second option for nonweight-bearing areas. Overall, this combined approach provides an effective and safe method for reconstruction of extensive plantar wounds.

Acral melanoma: new insights into the immune and genomic landscape

Acral melanoma is a rare subtype of melanoma that arises on the non-hair bearing skin of the nail bed, palms of the hand and soles of the feet. It is unique among melanomas in not being linked to ultraviolet radiation (UVR) exposure from the sun, and, as such, its incidence is similar across populations who are of Asian, Hispanic, African and European origin. Although research into acral melanoma has lagged behind that of sun-exposed cutaneous melanoma, recent studies have begun to address the unique genetics and immune features of acral melanoma. In this review we will discuss the latest progress in understanding the biology of acral melanoma across different ethnic populations and will outline how these new discoveries can help to guide the therapeutic management of this rare tumor.

Survival impact of immediate complete lymph node dissection for Chinese acral and cutaneous melanoma with micrometastasis in sentinel nodes: a retrospective study

Sentinel node biopsy (SNB) has become a critical part of standard surgical treatment for melanoma with no clinical metastatic evidence. However, for patients with a positive sentinel node, the MSLT-II and DeCOG-SLT trials have shown that immediate complete lymph node dissection (CLND) does not bring further survival benefits. There is still an argument among the Chinese population dominated by acral subtypes on whether CLND can be omitted. Thus, this study aims to investigate the impact of immediate CLND on relapse-free survival (RFS) in Chinese melanoma patients with a positive sentinel node. Patients with acral or cutaneous melanoma of clinical Stages I-II who received SNB procedure and were detected with nodal micrometastasis were retrospectively collected at Fudan University Cancer Center (FUSCC) from January 2017 to December 2021. The clinicopathologic features and prognostic factors for RFS were analyzed. Out of 381 patients who received SNB in the past 5 years, 130 (34%) cases with SN micrometastasis detected were included in this study. Ninety-nine patients underwent immediate CLND while the other 31 patients received observation alone. Among patients who received CLND, the non-SN(NSN)-positive rate was 22.2%. Most of the clinicopathologic factors were balanced well between the CLND and non-CLND groups. However, more patients in the CLND group were detected with BRAF and NRAS mutation (P = 0.006) and received adjuvant PD-1 monotherapy (P = 0.042) as well. There were slightly fewer N1 patients in the CLND group, although the difference did not reach statistical significance (P = 0.075). The study found no significant difference in RFS between the two groups (P = 0.184). Even for patients with the acral subtype (P = 0.925), primary T4 lesion (P = 0.769), or presence of ulceration (P = 0.249), immediate CLND did not bring more survival benefits. Immediate CLND did not bring further RFS benefit for Chinese melanoma patients with SN micrometastasis in real-world clinical practice, even for patients with acral subtype or more tumor burden such as thick Breslow invasion and ulceration.

Diagnosis and Management of Acral Pigmented Lesions

BACKGROUND

Survival outcomes in acral lentiginous melanoma (ALM) are worse than for cutaneous melanoma. Diagnostic delays are believed to contribute to worse outcomes in ALM, including advanced-stage disease at initial presentation. Acral lentiginous melanoma, especially in its early stages, may be difficult to discern from benign pigmented acral lesions.

OBJECTIVE

The purpose of this article is to provide a comprehensive review of the diagnosis and management of acral pigmented lesions.

MATERIALS AND METHODS

A literature review was performed. The outcomes included were the clinical and dermoscopic features and the management frameworks and considerations for acquired and congenital melanocytic nevi, acral melanosis, nonmelanocytic pigmented lesions, and ALM.

RESULTS

Original research studies were primarily included. The use of dermoscopy, such as the 3-step algorithm and blotch (irregular), ridge pattern (parallel), asymmetry of structures, asymmetry of colors, furrow pattern (parallel), fibrillar pattern (BRAAFF) checklist, increases the diagnostic accuracy of acral pigmented lesions with high specificity and sensitivity. Short-term digital dermoscopic surveillance can be used to manage acral lesions, and histopathology should be collected when there is a concern for ALM.

CONCLUSION

The use of dermoscopy and an understanding of how to manage acral lesions may limit the number of biopsies performed on the acral skin, decrease the time to diagnosis, and facilitate early detection of ALM.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of melanoma, version 3.0

Since the first approval for immune checkpoint inhibitors (ICIs) for the treatment of cutaneous melanoma more than a decade ago, immunotherapy has completely transformed the treatment landscape of this chemotherapy-resistant disease. Combination regimens including ICIs directed against programmed cell death protein 1 (PD-1) with anti-cytotoxic T lymphocyte antigen-4 (CTLA-4) agents or, more recently, anti-lymphocyte-activation gene 3 (LAG-3) agents, have gained regulatory approvals for the treatment of metastatic cutaneous melanoma, with long-term follow-up data suggesting the possibility of cure for some patients with advanced disease. In the resectable setting, adjuvant ICIs prolong recurrence-free survival, and neoadjuvant strategies are an active area of investigation. Other immunotherapy strategies, such as oncolytic virotherapy for injectable cutaneous melanoma and bispecific T-cell engager therapy for HLA-A*02:01 genotype-positive uveal melanoma, are also available to patients. Despite the remarkable efficacy of these regimens for many patients with cutaneous melanoma, traditional immunotherapy biomarkers (ie, programmed death-ligand 1 expression, tumor mutational burden, T-cell infiltrate and/or microsatellite stability) have failed to reliably predict response. Furthermore, ICIs are associated with unique toxicity profiles, particularly for the highly active combination of anti-PD-1 plus anti-CTLA-4 agents. The Society for Immunotherapy of Cancer (SITC) convened a panel of experts to develop this clinical practice guideline on immunotherapy for the treatment of melanoma, including rare subtypes of the disease (eg, uveal, mucosal), with the goal of improving patient care by providing guidance to the oncology community. Drawing from published data and clinical experience, the Expert Panel developed evidence- and consensus-based recommendations for healthcare professionals using immunotherapy to treat melanoma, with topics including therapy selection in the advanced and perioperative settings, intratumoral immunotherapy, when to use immunotherapy for patients with BRAFV600-mutated disease, management of patients with brain metastases, evaluation of treatment response, special patient populations, patient education, quality of life, and survivorship, among others.

Acral lentiginous melanoma incidence by sex, race, ethnicity, and stage in the United States, 2010-2019

INTRODUCTION

Acral lentiginous melanoma (ALM) is a rare type of melanoma associated with delayed diagnosis and poor survival rates. This study examines ALM incidence rates in comparison to all other melanoma types.

METHODS

We used data from the Centers for Disease Control and Prevention's National Program of Cancer Registries and the National Cancer Institute's Surveillance, Epidemiology, and End Results Program, which together cover 99% of the US population. We calculated age-adjusted rates and rate ratios for ALM and all other malignant melanomas by sex, race and ethnicity, stage, and year of diagnosis (2010-2019).

RESULTS

ALM incidence rates were significantly lower among non-Hispanic Black persons (1.8 per 1,000,000); non-Hispanic Asian/Pacific Islander (API) persons (1.7 per 1,000,000); and Hispanic Black, American Indian/Alaska Native (AI/AN), and API persons (1.5 per 1,000,000) compared to non-Hispanic White persons (2.3 per 1,000,000). Rates were significantly higher among Hispanic White persons (2.8 per 1,000,000) compared to non-Hispanic White persons. For all other melanoma types, incidence rates were significantly higher among non-Hispanic White persons compared to persons in each of the other racial and ethnic categories. The percentage of melanomas that were ALM ranged from 0.8% among non-Hispanic White persons to 19.1% among Hispanic Black, AI/AN, and API persons.

CONCLUSION

These findings suggest that awareness of the potential for ALM in patients of all races and ethnicities could be balanced with an understanding of the rarity of the disease and the potential for the development of other melanoma types in racial and ethnic minority groups.

Lower limb cutaneous melanoma surgery: location matters

The anatomical location of cutaneous melanoma is a relevant independent prognostic factor in melanoma. The aim of the study is to know the prognosis of lower limb cutaneous melanoma related to their location within the limb, regardless of the histological type, and if there are any other influencing variables. A real-world data observational study was developed. The lesions were divided depending on the location of the melanoma (thigh, leg and foot). Bivariate and multivariate analysis were performed, and melanoma-specific survival and disease-free survival rates were calculated. When these analysis were done, the results showed that, in melanomas of the lower limb, location on the foot presented a lower melanoma-specific survival rate compared to more proximal locations, and only the anatomical location presents statistical significance to discriminate cases with a higher mortality risk and a lower disease-free survival rate among distal melanomas (mainly on the foot). In conclusion, this study confirms that a more distal location of lower limb cutaneous melanoma is a relevant prognostic factor.Trial registration number NCT04625491 retrospectively registered.

Undereducation is afoot: Assessing the lack of acral lentiginous melanoma educational materials for skin of color

Acral lentiginous melanoma (ALM) is a subtype of cutaneous melanoma notorious for poor outcomes that disproportionately affect individuals with skin of color (e.g., African-, Hispanic-, Asian-descent) when compared to mortality rates among non-Hispanic White populations. There are several societal factors that contribute to racial disparities in ALM, including a lack of representative educational material in the context of patient education and medical instruction. This gap in representative information for the US population includes risk of disease, patterns of incidence, and differences in disease presentation in skin of color. The atypical presentation of ALM on acral volar skin sites makes early detection challenging and necessitates an increased index of suspicion on the part of physicians and patients alike. Studies underscoring the importance of early detection in reducing mortality risk make the availability of adequate representative educational materials indispensable.

Melanoma in skin of color: Part I. Epidemiology and clinical presentation

Although there is a higher incidence of melanoma among non-Hispanic White individuals, melanoma is diagnosed at more advanced stages and associated with worse survival rates among individuals with skin of color (SOC). The proportions of melanoma subtypes differ across racial groups, with acral lentiginous melanoma and mucosal melanoma representing higher proportions of melanoma diagnoses in individuals with SOC compared to White individuals. The recognition of distinct differences in anatomic locations and dermatoscopic patterns may facilitate the appropriate differentiation of physiologic from pathologic pigmentation. The first article of this continuing medical education series will focus on the epidemiology and clinical presentation of melanoma in individuals with SOC, with the aim of improving early diagnoses and clinical outcomes.

Melanoma in skin of color: Part II. Racial disparities, role of UV, and interventions for earlier detection

Despite a higher incidence of melanoma among White individuals, melanoma-specific survival is worse among individuals with skin of color. Racial disparities in survival are multifactorial. Decreased skin cancer education focused on people with skin of color, lower rates of screening, increased socioeconomic barriers, higher proportions of more aggressive subtypes, and underrepresentation in research and professional education contribute to delays in diagnosis and treatment. Although high, intermittent UV exposure during childhood has been established as a significant modifiable risk factor for melanoma in individuals with lighter skin phototypes, there are limited data on UV exposure and melanoma risk in people with darker skin phototypes. The second article of this continuing medical education series will examine factors contributing to racial disparities in melanoma-specific survival, discuss the role of UV radiation, and address the need for further research and targeted educational interventions for melanoma in individuals with skin of color.

Acral Melanoma Is Infiltrated with cDC1s and Functional Exhausted CD8 T Cells Similar to the Cutaneous Melanoma of Sun-Exposed Skin

Acral melanoma (AM) is the most common melanoma in non-Caucasian populations, yet it remains largely understudied. As AM lacks the UV-radiation mutational signatures that characterize other cutaneous melanomas, it is considered devoid of immunogenicity and is rarely included in clinical trials assessing novel immunotherapeutic regimes aiming to recover the antitumor function of immune cells. We studied a Mexican cohort of melanoma patients from the Mexican Institute of Social Security (IMSS) (n = 38) and found an overrepresentation of AM (73.9%). We developed a multiparametric immunofluorescence technique coupled with a machine learning image analysis to evaluate the presence of conventional type 1 dendritic cells (cDC1) and CD8 T cells in the stroma of melanoma, two of the most relevant immune cell types for antitumor responses. We observed that both cell types infiltrate AM at similar and even higher levels than other cutaneous melanomas. Both melanoma types harbored programmed cell death protein 1 (PD-1+) CD8 T cells and PD-1 ligand (PD-L1+) cDC1s. Despite this, CD8 T cells appeared to preserve their effector function and expanding capacity as they expressed interferon-γ (IFN-γ) and KI-67. The density of cDC1s and CD8 T cells significantly decreased in advanced stage III and IV melanomas, supporting these cells' capacity to control tumor progression. These data also argue that AM could respond to anti-PD-1-PD-L1 immunotherapy.

Human epidermal growth factor receptor 3 serves as a novel therapeutic target for acral melanoma

Acral melanoma (AM) is a rare, life-threatening skin cancer. Since AM bears unique features, existing therapies for other types of malignant melanomas have limited effects and the establishment of effective treatments for AM is strongly desired. Human epidermal growth factor receptor 3 (HER3) is a receptor tyrosine kinase that is frequently elevated in tumors and contributes to tumor progression, so it is considered a promising therapeutic target for tumors. This study was established to evaluate the potential of HER3-targeted therapy to treat AM by investigating the expression and function of HER3. HER3 expression was immunohistochemically analyzed in AM lesions of 72 patients and in AM cell lines. To investigate function of HER3, effects of HER3 inhibition on cell proliferation, apoptosis/survival, anchorage-independent growth, and underlying signals were assessed. HER3 was expressed in patients' AM tissues with various intensities and HER3 expression was significantly correlated with patient's disease-free survival. In vitro analyses revealed that HER3 is more highly expressed in AM cells than in normal epidermal melanocytes. AM cells were also shown to be sensitive to the cytotoxic part of a HER3-targeted antibody-drug conjugate. Inhibition of HER3 did not affect cell proliferation, whereas it decreased the anchorage-independent growth of AM cells likely through affecting the nuclear translocation of Yes-associated protein. It is implied that HER3 may serve as a novel therapeutic target for AM.

Variations in genetics, biology, and phenotype of cutaneous disorders in skin of color - Part I: Genetic, biologic, and structural differences in skin of color

Skin of color (SOC) populations include those who identify as Black/African, Hispanic/Latinx, Asian/Pacific Islander, American Indian/Native Alaskan, Indigenous Australian, Middle Eastern, biracial/multiracial, or non-White; this list is far from exhaustive and may vary between and within cultures. Recent genetic and immunological studies have suggested that cutaneous inflammatory disorders (atopic dermatitis, psoriasis, and hidradenitis suppurativa) and malignancies (melanoma, basal cell carcinoma, and cutaneous T-cell lymphoma) may have variations in their immunophenotype among SOC. Additionally, there is growing recognition of the substantial role social determinants of health play in driving health inequalities in SOC communities. It is critically important to understand that social determinants of health often play a larger role than biologic or genetic factors attributed to "race" in health care outcomes. Herein, we describe the structural, genetic, and immunological variations and the potential implications of these variations in populations with SOC. This article underscores the importance of increasing the number of large, robust genetic studies of cutaneous disorders in SOC to create more targeted, effective therapies for this often underserved and understudied population. Part II of this CME will highlight the clinical differences in the phenotypic presentation of and the health disparities associated with the aforementioned cutaneous disorders in SOC.

Differences in the demographics, incidence, and survival of palmar and plantar acral melanoma: a population-based study

Acral melanoma (AM) has the worst prognosis of all cutaneous malignant melanomas (CMM). Differences between palmar and plantar tumors have not been well characterized at the population level. The objective of this study was to investigate the differences in demographics, incidence, and survival between palmar and plantar AM. The 2004-2016 National Cancer Database (NCDB) and 2000-2018 Surveillance, Epidemiology, and Results (SEER) databases were used to evaluate differences between palmar and plantar AM. Data were analyzed using Chi-square test, Fisher's exact, T-test, or likelihood ratio test. A total of 5002 participants were included in the study. A greater percentage of tumors occurred on the plantar surface (82.0%) than the palmar surface (18.0%). The incidence of plantar tumors is four times greater than palmar tumors (1.7 vs 0.4 cases per 1,000,000 people per year). Palmar melanomas were more likely to occur in Whites (84.6% vs 76.8%, p < 0.001) and be treated with amputation (28.1% vs 12.9%, p < 0.001) compared to plantar melanomas. Disease-specific five-year survival was similar for all palmar (80.8%) and plantar tumors (78.2%). While subtle differences do exist between palmar and plantar tumors, they behave similarly overall and should be treated as one entity.

Major Histotypes in Skin Melanoma: Nodular and Acral Lentiginous Melanomas Are Poor Prognostic Factors for Relapse and Survival

ABSTRACT

The histological subtype is not considered one of the major prognostic factors in melanoma, yet it is known to have an impact on survival. The aim of this study was to investigate the clinical significance of histological subtypes and the possible impacts of clinicopathological factors on the course of melanoma patients of all stages. A total of 1017 cutaneous melanoma patients were analyzed retrospectively. Four major melanoma histotypes that were studied in this study were as follows: (1) superficial spreading melanoma (SSM), (2) nodular melanoma (NM), (3) acral lentiginous melanoma (ALM), and (4) lentigo maligna melanoma (LMM). Unlike SSMs and LMMs, there were statistically significant correlations between NMs and ALMs and most aggressive histopathological prognostic indicators, such as higher Clark level ( P = 0.0001), thick Breslow depth ( P = 0.0001), presence of ulceration ( P = 0.0001), and lymphovascular invasion ( P = 0.0001). Furthermore, NMs and ALMs were also associated with advanced clinical stages, that is, node involvement and metastasis. Relapse rates for nonmetastatic melanomas were higher in NMs (39.6%) and ALMs (35.3%) than in SSMs (24.3%) and LMMs (10.3%) ( P = 0.0001). Additionally, 5-year relapse-free survival rates were 90.5%, 70.5%, 55.7%, and 50.5% in LMMs, SSMs, ALMs, and NMs, respectively ( P = 0.0001). Moreover, 5-year overall survival rates plummeted from 84.3% in LMMs to 74.8%, 64.3%, and 46% in SSMs, ALMs, and NMs, respectively ( P = 0.0001). In conclusion, we observed that the histologic subtype was an independent predictor for relapse and outcome for cutaneous melanoma patients. Both NM and ALM had unfavorable prognoses, and they were associated with known poor pathological and clinical indicators.

Clinical features, molecular pathology, and immune microenvironmental characteristics of acral melanoma

Acral melanoma (AM) has unique biology as an aggressive subtype of melanoma. It is a common subtype of melanoma in races with darker skin tones usually diagnosed at a later stage, thereby presenting a worse prognosis compared to cutaneous melanoma. The pathogenesis of acral melanoma differs from cutaneous melanoma, and trauma promotes its development. Compared to cutaneous melanomas, acral melanomas have a significantly lighter mutational burden with more copy number variants. Most acral melanomas are classified as triple wild-type. In contrast to cutaneous melanomas, acral melanomas have a suppressive immune microenvironment. Herein, we reviewed the clinical features, genetic variants, and immune microenvironmental characteristics of limbic melanomas to summarise their unique features.

Integrated genomic analyses of acral and mucosal melanomas nominate novel driver genes

BACKGROUND

Acral and mucosal melanomas are aggressive subtypes of melanoma, which have a significantly lower burden of somatic mutations than cutaneous melanomas, but more frequent copy number variations, focused gene amplifications, and structural alterations. The landscapes of their genomic alterations remain to be fully characterized.

METHODS

We compiled sequencing data of 240 human acral and mucosal melanoma samples from 11 previously published studies and applied a uniform pipeline to call tumor cell content, ploidy, somatic and germline mutations, as well as CNVs, LOH, and SVs. We identified genes that are significantly mutated or recurrently affected by CNVs and implicated in oncogenesis. We further examined the difference in the frequency of recurrent pathogenic alterations between the two melanoma subtypes, correlation between pathogenic alterations, and their association with clinical features.

RESULTS

We nominated PTPRJ, mutated and homozygously deleted in 3.8% (9/240) and 0.8% (2/240) of samples, respectively, as a probable tumor suppressor gene, and FER and SKP2, amplified in 3.8% and 11.7% of samples, respectively, as probable oncogenes. We further identified a long tail of infrequent pathogenic alterations, involving genes such as CIC and LZTR1. Pathogenic germline mutations were observed on MITF, PTEN, ATM, and PRKN. We found BRAF V600E mutations in acral melanomas with fewer structural variations, suggesting that they are distinct and related to cutaneous melanomas. Amplifications of PAK1 and GAB2 were more commonly observed in acral melanomas, whereas SF3B1 R625 codon mutations were unique to mucosal melanomas (12.9%). Amplifications at 11q13-14 were frequently accompanied by fusion to a region on chromosome 6q12, revealing a recurrent novel structural rearrangement whose role remains to be elucidated.

CONCLUSIONS

Our meta-analysis expands the catalog of driver mutations in acral and mucosal melanomas, sheds new light on their pathogenesis and broadens the catalog of therapeutic targets for these difficult-to-treat cancers.

Response to immune checkpoint inhibitors in acral melanoma: A nationwide cohort study

BACKGROUND

Recent reports suggest the limited efficacy of immune checkpoints inhibitors in advanced acral melanoma (AM). This study aims to investigate the clinical outcomes of immune checkpoint inhibitors in patients with stage III and IV AM and compare them to cutaneous melanoma (CM).

METHODS

We included patients with advanced AM and CM treated with first-line anti-programmed cell death (PD)-1 monotherapy or ipilimumab-nivolumab registered in the prospective nationwide Dutch Melanoma Treatment Registry. Objective response rates, progression-free survival (PFS) and overall survival (OS) were calculated. A Cox proportional hazard model was used to assess the prognostic factors with PFS and OS.

RESULTS

In total, 2058 patients (88 AM and 1970 CM) with advanced melanoma were included. First-line objective response rates were 34% for AM versus 54% for CM in the advanced anti-PD-1 cohort and 33% for AM versus 53% for CM in the advanced ipilimumab-nivolumab cohort. The Median PFS was significantly shorter for anti-PD-1 treated AM patients (3.1 months; 95%CI: 2.8-5.6) than patients with CM (10.1 months; 95%CI: 8.5-12.2) (P < 0.001). In patients with advanced melanoma, AM was significantly associated with a higher risk of progression (HRadj 1.63; 95%CI: 1.26-2.11; P < 0.001) and death (HRadj 1.54; 95%CI: 1.15-2.06; P = 0.004) than CM.

CONCLUSIONS

This study shows lower effectiveness of anti-PD -1 monotherapy and ipilimumab-nivolumab in AM, with lower response rates, PFS and OS than CM. This group of patients should be prioritised in the development of alternative treatment strategies.

TRPM1 promotes tumor progression in acral melanoma by activating the Ca2+/CaMKIIδ/AKT pathway

INTRODUCTION

Acral melanoma is a predominant and aggressive subtype of melanoma in non-Caucasian populations. There is a lack of genotype-driven therapies for over 50% of patients. TRPM1 (transient receptor potential melastatin 1), a nonspecific cation channel, is mainly expressed in retinal bipolar neurons and skin. Nonetheless, the function of TRPM1 in melanoma progression is poorly understood.

OBJECTIVES

We investigated the association between TRPM1 and acral melanoma progression and revealed the molecular mechanisms by which TRPM1 promotes tumor progression and malignancy.

METHODS

TRPM1 expression and CaMKII phosphorylation in tumor specimens were tested by immunohistochemistry analysis and scored by two independent investigators. The functions of TRPM1 and CaMKII were assessed using loss-of-function and gain-of-function approaches and examined by western blotting, colony formation, cell migration and invasion, and xenograft tumor growth assays. The effects of a CaMKII inhibitor, KN93, were evaluated using both in vitro cell and in vivo xenograft mouse models.

RESULTS

We revealed that TRPM1 protein expression was positively associated with tumor progression and shorter survival in patients with acral melanoma. TRPM1 promoted AKT activation and the colony formation, cell mobility, and xenograft tumor growth of melanoma cells. TRPM1 elevated cytosolic Ca²⁺ levels and activated CaMKIIδ (Ca²⁺/calmodulin-dependent protein kinase IIδ) to promote the CaMKIIδ/AKT interaction and AKT activation. The functions of TRPM1 in melanoma cells were suppressed by a CaMKII inhibitor, KN93. Significant upregulation of phospho-CaMKII levels in acral melanomas was related to increased expression of TRPM1. An acral melanoma cell line with high expression of TRPM1, CA11, was isolated from a patient to show the anti-tumor activity of KN93 in vitro and in vivo.

CONCLUSIONS

TRPM1 promotes tumor progression and malignancy in acral melanoma by activating the Ca^2+/CaMKIIδ/AKT pathway. CaMKII inhibition may be a potential therapeutic strategy for treating acral melanomas with high expression of TRPM1.

Skin Cancer in People of Color: A Systematic Review

BACKGROUND

People of African, Asian, Hispanic or Latino, Pacific Islander, and Native Indian descent are considered people of color by the Skin of Color Society (SOCS).

OBJECTIVES

In this study, we assess incidence, risk factors, clinical characteristics, histopathology, treatment, and survival for skin malignancies in people of color as defined by the SOCS, by systematically reviewing the literature.

METHODS

An electronic literature search of the PubMed, EMBASE, and MEDLINE databases was performed. Articles published from 1 January 1990 through 12 December 2020 were included in the search.

RESULTS

We identified 2666 publications potentially meeting the study criteria. Titles and abstracts of these studies were reviewed and 2353 were excluded. The full text of 313 articles were evaluated and 251 were included in this review.

CONCLUSION

Differences in incidence, patterns, treatment, and survival exist among people of color for cutaneous malignancies. Further research and initiatives are needed to account for and mitigate these differences.

Un-Fair Skin: racial disparities in acral melanoma research

Patients of colour predominately present with acral lentiginous melanoma (ALM), the most lethal subtype of cutaneous melanoma. We here advocate for increased mechanistic studies using models derived from the patient communities suffering most from ALM to develop therapies that benefit patients across all ethnic and racial groups.

Survival differences in acral lentiginous melanoma according to socioeconomic status and race

BACKGROUND

Relationships of socioeconomic status (SES) and race to survival in acral lentiginous melanoma (ALM) are poorly characterized.

OBJECTIVE

To compare disease-specific survival in ALM across SES and race.

METHODS

Retrospective cohort study using the Surveillance, Epidemiology, and End Results database, 2000 to 2016.

RESULTS

We identified 2245 patients with a first ALM diagnosis. Five-year disease-specific survival was 77.8% (95% CI, 75.9%-79.9%). After adjustment, patients in the lowest and second-to-lowest SES quintile had 1.33 (95% CI, 0.90-1.96) and 1.42 (95% CI, 1.03-1.97) times the risk of death, respectively, compared to highest quintile patients. Hispanic White and Black patients had 1.48 (95% CI, 1.10-1.99) and 1.25 (95% CI, 0.88-1.79) times the risk of death, respectively, compared to non-Hispanic Whites. Hazard ratios for ALM-specific death decreased in Hispanic White and Black patients after adjusting for SES and American Joint Committee on Cancer stage at diagnosis.

LIMITATIONS

Treatments could not be evaluated. SES was measured at the level of the census tract and does not account for individual level factors.

CONCLUSION

Differences exist in ALM survival according to socioeconomic status and race. Differences in SES and American Joint Committee on Cancer stage at diagnosis contribute to survival disparities for Hispanic White and Black patients. Understanding factors driving survival disparities related to SES and race may improve ALM outcomes.

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.

Acral Lentiginous Melanoma: A United States Multi-Center Substage Survival Analysis

Background

Acral lentiginous melanoma is associated with worse survival than other subtypes of melanoma. Understanding prognostic factors for survival and recurrence can help better inform follow-up care.

Objectives

To analyze the clinicopathologic features, melanoma-specific survival, and recurrence-free survival by substage in a large, multi-institutional cohort of primary acral lentiginous melanoma patients.

Methods

Retrospective review of the United States Melanoma Consortium database, a multi-center prospectively collected database of acral lentiginous melanoma patients treated between January 2000 and December 2017.

Results

Of the 433 primary acral lentiginous melanoma patients identified (median [range] age: 66 [8–97] years; 53% female, 83% white), 66% presented with stage 0–2 disease and the median time of follow-up for the 392 patients included in the survival analysis was 32.5 months (range: 0–259). The 5-year melanoma-specific survivals by stage were 0 = 100%, I = 93.8%, II = 76.2%, III = 63.4%, IIIA = 80.8%, and IV = 0%. Thicker Breslow depth ((HR) = 1.13; 95% CI = 1.05–1.21; P < .001)) and positive nodal status ((HR) = 1.79; 95% CI = 1.00–3.22; P = .050)) were independent prognostic factors for melanoma-specific survival. Breslow depth ((HR = 1.13; 95% CI = 1.07–1.20; P < .001), and positive nodal status (HR = 2.12; 95% CI = 1.38–3.80; P = .001) were also prognostic factors for recurrence-free survival.

Conclusion

In this cohort of patients, acral lentiginous melanoma was associated with poor outcomes even in early stage disease, consistent with prior reports. Stage IIB and IIC disease were associated with particularly low melanoma-specific and recurrence-free survival. This suggests that studies investigating adjuvant therapies in stage II patients may be especially valuable in acral lentiginous melanoma patients.