Immune Checkpoint Inhibitors in Advanced Acral Melanoma: A Systematic Review

Clinical Characteristics and Special Considerations in the Management of Rare Melanoma Subtypes

Rare histologic subtypes of melanoma, including acral, mucosal, uveal, and desmoplastic melanomas, only make up 5% of all diagnosed melanomas and are often underrepresented in large, randomized trials. Recent advancements in systemic therapy have shown marked improvement in pathologic response rates, improving progression-free and overall survival among cutaneous melanoma patients, but there are limited data to demonstrate improved survival among rarer subtypes of melanoma. Acral melanoma has a poor response to immunotherapy and is associated with worse survival. Mucosal melanoma has a large variability in its presentation, a poor prognosis, and a low mutational burden. Uveal melanoma is associated with a high rate of liver metastasis; recent adoption of infusion and perfusion therapies has demonstrated improved survival among these patients. Desmoplastic melanoma, a high-risk cutaneous melanoma, is associated with high locoregional recurrence rates and mutational burden, suggesting this melanoma may have enhanced response to immunotherapy. While these variants of melanoma represent distinct disease entities, this review highlights the clinicopathologic characteristics and treatment recommendations for each of these rare melanomas and highlights the utility of modern therapies for each of them.

Nilotinib in KIT-driven advanced melanoma: Results from the phase II single-arm NICAM trial

Mucosal (MM) and acral melanomas (AM) are rare melanoma subtypes of unmet clinical need; 15%-20% harbor KIT mutations potentially targeted by small-molecule inhibitors, but none yet approved in melanoma. This multicenter, single-arm Phase II trial (NICAM) investigates nilotinib safety and activity in KIT mutated metastatic MM and AM. KIT mutations are identified in 39/219 screened patients (18%); of 29/39 treated, 26 are evaluable for primary analysis. Six patients were alive and progression free at 6 months (local radiology review, 25%); 5/26 (19%) had objective response at 12 weeks; median OS was 7.7 months; ddPCR assay correctly identifies KIT alterations in circulating tumor DNA (ctDNA) in 16/17 patients. Nilotinib is active in KIT-mutant AM and MM, comparable to other KIT inhibitors, with demonstrable activity in nonhotspot KIT mutations, supporting broadening of KIT evaluation in AM and MM. Our results endorse further investigations of nilotinib for the treatment of KIT-mutated melanoma. This clinical trial was registered with ISRCTN (ISRCTN39058880) and EudraCT (2009-012945-49).

Melanoma biology and treatment: a review of novel regulated cell death-based approaches

The incidence of melanoma, the most lethal form of skin cancer, has increased due to ultraviolet exposure. The treatment of advanced melanoma, particularly metastatic cases, remains challenging with poor outcomes. Targeted therapies involving BRAF/MEK inhibitors and immunotherapy based on anti-PD1/anti-CTLA4 antibodies have achieved long-term survival rates of approximately 50% for patients with advanced melanoma. However, therapy resistance and inadequate treatment response continue to hinder further breakthroughs in treatments that increase survival rates. This review provides an introduction to the molecular-level pathogenesis of melanoma and offers an overview of current treatment options and their limitations. Cells can die by either accidental or regulated cell death (RCD). RCD is an orderly cell death controlled by a variety of macromolecules to maintain the stability of the internal environment. Since the uncontrolled proliferation of tumor cells requires evasion of RCD programs, inducing the RCD of melanoma cells may be a treatment strategy. This review summarizes studies on various types of nonapoptotic RCDs, such as autophagy-dependent cell death, necroptosis, ferroptosis, pyroptosis, and the recently discovered cuproptosis, in the context of melanoma. The relationships between these RCDs and melanoma are examined, and the interplay between these RCDs and immunotherapy or targeted therapy in patients with melanoma is discussed. Given the findings demonstrating melanoma cell death in response to different stimuli associated with these RCDs, the induction of RCD shows promise as an integral component of treatment strategies for melanoma.

Phase Ib study of anlotinib in combination with anti-PD-L1 antibody (TQB2450) in patients with advanced acral melanoma

BACKGROUND

Acral melanoma, the most common subtype of melanoma in Asians, is often diagnosed at an advanced stage and responds poorly to current programmed cell death protein 1 (PD-1) inhibitors.

OBJECTIVES

To evaluate the safety and efficacy of TQB2450 and anlotinib in patients with advanced acral melanoma in a phase Ib study (NCT03991975).

METHODS

Patients received TQB2450 (1200 mg every 3 weeks) and anlotinib (10 mg or 12 mg once daily, 2-week on/1-week off) in the dose-escalation and dose-expansion phases. The primary endpoints were dose-limiting toxicity (DLT), maximum tolerated dose (MTD) and objective response rate (ORR).

RESULTS

Nineteen patients were enrolled between June 2019 and June 2022. The majority of patients (16 of 19 patients) received anlotinib and TQB2450 as first-line treatment. No DLTs were observed, and MTD was not reached. Eighteen (94.7%) out of 19 patients experienced treatment-related adverse events (TRAEs), but most were grade 1 or 2. Grade 3 or greater TRAEs occurred in seven patients (36.8%). The ORR was 26.3% (two complete responses and three partial responses). The disease control rate was 73.7%. The median duration of response was 30.3 months [95% confidence interval (CI): 5.8-NA]. The median progression-free survival (PFS) was 5.5 months (95% CI: 2.8-NA), and median overall survival was 20.3 months (95% CI: 14.8-NA). Whole-exome sequencing suggested that acquired drug resistance might be attributed to activation of the MAPK signalling pathway and transformation to an immunosuppressive tumour environment.

CONCLUSIONS

TQB2450 combined with anlotinib showed favourable tolerance and promising anti-tumour activity with a prolonged PFS compared with anti-PD1 monotherapy in patients with advanced acral melanoma.

Slow Mohs micrographic surgery for nail apparatus melanoma in situ

BACKGROUND

Nail apparatus melanoma is a malignant tumor with a high incidence in Chinese melanoma patients. Slow Mohs micrographic surgery is an emerging technique for treating nail apparatus melanoma in situ (NAMIS).

OBJECTIVE

This study evaluated the efficacy and safety of slow Mohs micrographic surgery for treating NAMIS.

METHODS

Patients were enrolled in this retrospective study and treated in a single center from October 1, 2016, to June 30, 2022. Each patient underwent standard slow Mohs micrographic surgery, and follow-up was regularly conducted at clinics.

RESULTS

Ten patients were enrolled in the study. Two patients underwent one Mohs stage, seven underwent two Mohs stages, and one underwent seven Mohs stages. The resection margin ranged from 5 to 25 mm. No severe complications were reported in the treatment, and recurrence of NAMIS was not observed during the follow-up period.

CONCLUSION

Slow Mohs micrographic surgery is a valuable surgical method to treat NAMIS that preserves digit function and can be well tolerated by patients.

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.

Efficacy of salvage therapies for advanced acral melanoma after anti-PD-1 monotherapy failure: a multicenter retrospective study of 108 Japanese patients

Background

Anti-programmed cell death protein 1 (PD-1) monotherapy is one of the standard systemic therapies for advanced melanoma; however, the efficacy of salvage systemic therapies after PD-1 monotherapy failure (PD-1 MF), particularly in acral melanoma (AM), the main clinical melanoma type in Japanese patients, is unclear. This study aimed to investigate the efficacy of salvage systemic therapies in Japanese patients with AM after PD-1 MF.

Patients and methods

The study included 108 patients with advanced AM (palm and sole, 72; nail apparatus, 36) who underwent salvage systemic therapy at 24 Japanese institutions. We mainly assessed the objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).

Results

Thirty-six (33%) patients received ipilimumab, 23 (21%) received nivolumab and ipilimumab (nivo/ipi), 10 (9%) received cytotoxic chemotherapy, 4 (4%) received BRAF and MEK inhibitors (BRAFi/MEKi), and the remaining 35 (32%) continued with PD-1 monotherapy after disease progression. The ORRs in the ipilimumab, nivo/ipi, cytotoxic chemotherapy, and BRAFi/MEKi groups were 8, 17, 0, and 100%, respectively. The nivo/ipi group showed the longest OS (median, 18.9 months); however, differences in ORR, PFS, and OS between the groups were insignificant. The OS in the nivo/ipi group was higher in the palm and sole groups than in the nail apparatus group (median: not reached vs. 8.7 months, p < 0.001). Cox multivariate analysis demonstrated that nail apparatus melanoma independently predicted unfavorable PFS and OS (p = 0.006 and 0.001). The total OS (from PD-1 monotherapy initiation to death/last follow-up) was insignificant between the groups.

Conclusion

Nivo/ipi was not more effective than cytotoxic chemotherapy and ipilimumab after PD-1 MF in patients with advanced AM. The prognosis after PD-1 MF would be poorer for nail apparatus melanoma than for palm and sole melanoma.

Adult and Pediatric Nail Unit Melanoma: Epidemiology, Diagnosis, and Treatment

Nail unit melanoma (NUM) is an uncommon form of melanoma and is often diagnosed at later stages. Approximately two-thirds of NUMs are present clinically as longitudinal melanonychia, but longitudinal melanonychia has a broad differential diagnosis. Clinical examination and dermoscopy are valuable for identifying nail findings concerning malignancy, but a biopsy with histopathology is necessary to confirm a diagnosis of NUM. Surgical treatment options for NUM include en bloc excision, digit amputation, and Mohs micrographic surgery. Newer treatments for advanced NUM include targeted and immune systemic therapies. NUM in pediatric patients is extremely rare and diagnosis is challenging since both qualitative and quantitative parameters have only been studied in adults. There is currently no consensus on management in children; for less concerning melanonychia, some physicians recommend close follow-up. However, some dermatologists argue that the "wait and see" approach can cause delayed diagnosis. This article serves to enhance the familiarity of NUM by highlighting its etiology, clinical presentations, diagnosis, and treatment options in both adults and children.

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.

Impact of response patterns for patients with advanced acral melanoma treated with anti-programmed death-1 monotherapy

BACKGROUND

Acral melanoma (AM) is less responsive to immunotherapy than nonacral cutaneous melanoma. Variable responses are seen during immunotherapy, including pseudoprogression, hyperprogressive disease (HPD) and heterogeneous responses. There are currently no studies on the response patterns of patients with AM treated with immunotherapy and the impact on the outcome.

OBJECTIVES

To evaluate the response patterns and prognosis of patients with AM treated with anti-programmed death (PD)-1 antibodies.

METHODS

Patients with advanced AM treated prospectively in five clinical trials of anti-PD-1 monotherapy at Peking University Cancer Hospital were included. Responses of individual metastases and heterogeneous responses were evaluated during immunotherapy. Cox proportional hazards regression analysis was conducted to identify the possible predictive factors and generate a nomogram to predict the risk of 1-year and 2-year mortality.

RESULTS

The overall response rate was 18·0%, the disease control rate was 36·1%, median progression-free survival was 3·5 months [95% confidence interval (CI) 1·7-5·3] and median overall survival was 17·5 months (95% CI 15·1-19·9) for anti-PD-1 monotherapy. Overall, 9·8% of patients met the criteria of HPD, and displayed a dramatically worse outcome than patients without HPD. In total, 369 metastatic lesions were assessed, with the highest response rate in lymph nodes (20·4%) and the lowest in the liver (5·6%). Homogeneous response, heterogeneous response and heterogeneous or homogeneous progression had different prognoses from the best to the worst. A predictive model was constructed and achieved good accuracy with a C-index of 0·73 (95% CI 0·63-0·84) in the training set and 0·74 (95% CI 0·61-0·86) in the validation set.

CONCLUSIONS

HPD during immunotherapy serves as an essential biomarker of poor prognosis in advanced AM. Metastases in different sites respond distinctively to immunotherapy. Clinically heterogeneous responses to immunotherapy affect the outcome of patients. A predictive model was built to distinguish the prognosis of acral melanoma under immunotherapy.

Oncogenic alterations reveal key strategies for precision oncology in melanoma treatment

Background

Molecular profiling with next-generation sequencing (NGS) has been applied in multiple solid tumors, including melanomas, to identify potential drug targets. However, the association between clinical outcomes and the molecular alterations has not yet been fully clarified.

Methods

A total of 108 patients with melanoma were included in this study, 95 of whom had both sequencing data and clinical outcomes were collected. We analyzed the genetic alterations of 108 malignant melanoma patients using the OncoCare panel, which covers 559 genes.

Results

A model was also established to predict side effects through a combination analysis of clinical data and somatic variants, yielding an area under the receiver operating characteristic curve (AUROC) score of 0.8. We also identified epidermal growth factor receptor (EGFR) mutation was excellent predictor for progression-free survival (PFS) for patient who received immunotherapy (log-rank P=0.01), while tumor mutation burden (TMB) was found to not be significantly associated with PFS (log-rank P=0.87). Combining clinical features with genetic analysis, we found that patients carrying both DNA POLD1/ALOX12B or POLD1/PTPRT mutations had a significantly lower survival rate.

Conclusions

Overall, these results demonstrate the benefits of applying NGS clinical panels and shed light on future directions of personalized therapeutics for the treatment of melanoma.

Efficacy comparison between anti-PD-1 antibody monotherapy and anti-PD-1 plus anti-CTLA-4 combination therapy as first-line immunotherapy for advanced acral melanoma: A retrospective, multicenter study of 254 Japanese patients

BACKGROUND

Although anti-PD-1 antibody monotherapy (PD-1) is commonly used to treat advanced acral melanoma (AM), its efficacy is limited. Further, data on the efficacy of PD-1 plus anti-CTLA-4 antibody (PD-1+CTLA-4) for the treatment of AM are limited. Therefore, we compared the efficacy of PD-1+CTLA-4 and PD-1 in the treatment of Japanese patients with advanced AM.

METHODS

This retrospective study evaluated patients with advanced AM who were treated with PD-1 or PD-1+CTLA-4 as first-line immunotherapy in 24 Japanese institutions between 2014 and 2020. Treatment efficacy focussing on the objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) was compared between the two groups.

RESULTS

In total, 254 patients (palm and sole melanoma [PSM], n = 180; nail apparatus melanoma [NAM], n = 74) were included. Among the patients with PSM, the ORR (19% vs. 31%; P = 0.44), PFS (5.9 vs. 3.2 months; P = 0.74), and OS (23.1 vs. not reached; P = 0.55) did not differ significantly between the PD-1 and PD-1+CTLA-4 groups. Among the patients with NAM, the ORR (61% vs. 10%; P < 0.001) was significantly higher and PFS was longer (6.4 vs. 3.8 months; P = 0.10) in the PD-1+CTLA-4 group than in the PD-1 group. Cox multivariate analysis demonstrated that PD-1+CTLA-4 is an independent predictor of a favourable PFS in patients with NAM (P = 0.002).

CONCLUSIONS

The efficacy of PD-1+CTLA-4 is not superior to that of PD-1 for the treatment of advanced PSM. However, PD-1+CTLA-4 may be more efficacious than PD-1 for the treatment of advanced NAM.

Causes, consequences and clinical significance of aneuploidy across melanoma subtypes

Aneuploidy, the state of the cell in which the number of whole chromosomes or chromosome arms becomes imbalanced, has been recognized as playing a pivotal role in tumor evolution for over 100 years. In melanoma, the extent of aneuploidy, as well as the chromosomal regions that are affected differ across subtypes, indicative of distinct drivers of disease. Multiple studies have suggested a role for aneuploidy in diagnosis and prognosis of melanomas, as well as in the context of immunotherapy response. A number of key constituents of the cell cycle have been implicated in aneuploidy acquisition in melanoma, including several driver mutations. Here, we review the state of the art on aneuploidy in different melanoma subtypes, discuss the potential drivers, mechanisms underlying aneuploidy acquisition as well as its value in patient diagnosis, prognosis and response to immunotherapy treatment.

Advanced Acral Melanoma Therapies: Current Status and Future Directions

Melanoma is one of the deadliest malignancies. Its incidence has been significantly increasing in most countries in recent decades. Acral melanoma (AM), a peculiar subgroup of melanoma occurring on the palms, soles, and nails, is the main subtype of melanoma in people of color and is extremely rare in Caucasians. Although great progress has been made in melanoma treatment in recent years, patients with AM have shown limited benefit from current therapies and thus consequently have worse overall survival rates. Achieving durable therapeutic responses in this high-risk melanoma subtype represents one of the greatest challenges in the field. The frequency of BRAF mutations in AM is much lower than that in cutaneous melanoma, which prevents most AM patients from receiving treatment with BRAF inhibitors. However, AM has more frequent mutations such as KIT and CDK4/6, so targeted therapy may still improve the survival of some AM patients in the future. AM may be less susceptible to immune checkpoint inhibitors because of the poor immunogenicity. Therefore, how to enhance the immune response to the tumor cells may be the key to the application of immune checkpoint inhibitors in advanced AM. Anti-angiogenic drugs, albumin paclitaxel, or interferons are thought to enhance the effectiveness of immune checkpoint inhibitors. Combination therapies based on the backbone of PD-1 are more likely to provide greater clinical benefits. Understanding the molecular landscapes and immune microenvironment of AM will help optimize our combinatory strategies.

Management of Acral and Mucosal Melanoma: Medical Oncology Perspective

Acral and mucosal melanomas (MM) are rare subtypes of melanoma that are biologically and clinically distinct from cutaneous melanoma. Despite the progress in the treatment of cutaneous melanomas with the development of targeted and immune therapies, the therapeutic options for these less common subtypes remain limited. Difficulties in early diagnosis, the aggressive nature of the disease, and the frequently occult sites of origin have also contributed to the poor prognosis associated with acral and MM, with substantially worse long-term prognosis. The rarity of these subtypes has posed significant barriers to better understanding their biological features and investigating novel therapies. Consequently, establishing standardized treatment guidelines has been a challenge. In this review, we provide a brief overview of the current knowledge regarding acral and MM, focusing on their epidemiology, genetic backgrounds, and unique clinical characteristics. Further discussion centers around the management of primary and advanced disease and the role of emerging targeted and immune therapies for these subtypes, specifically focusing on issues relevant to medical oncologists.

Efficacy of anti-PD-1 and ipilimumab alone or in combination in acral melanoma

BACKGROUND

Acral melanoma is a rare melanoma subtype with poor prognosis. Importantly, these patients were not identified as a specific subgroup in the landmark melanoma trials involving ipilimumab and the anti-programmed cell death protein-1 (PD-1) agents nivolumab and pembrolizumab. There is therefore an absence of prospective clinical trial evidence regarding the efficacy of checkpoint inhibitors (CPIs) in this population. Acral melanoma has lower tumor mutation burden (TMB) than other cutaneous sites, and primary site is associated with differences in TMB. However the impact of this on the effectiveness of immune CPIs is unknown. We examined the efficacy of CPIs in acral melanoma, including by primary site.

METHODS

Patients with unresectable stage III/IV acral melanoma treated with CPI (anti-PD-1 and/or ipilimumab) were studied. Multivariable logistic and Cox regression analyses were conducted. Primary outcome was objective response rate (ORR); secondary outcomes were progression-free survival (PFS) and overall survival (OS).

RESULTS

In total, 325 patients were included: 234 (72%) plantar, 69 (21%) subungual and 22 (7%) palmar primary sites. First CPI included: 184 (57%) anti-PD-1, 59 (18%) anti-PD-1/ipilimumab combination and 82 (25%) ipilimumab. ORR was significantly higher with initial anti-PD-1/ipilimumab compared with anti-PD-1 (43% vs 26%, HR 2.14, p=0.0004) and significantly lower with ipilimumab (15% vs 26%, HR 0.49, p=0.0016). Landmark PFS at 1 year was highest for anti-PD-1/ipilimumab at 34% (95% CI 24% to 49%), compared with 26% (95% CI 20% to 33%) with anti-PD-1 and 10% (95% CI 5% to 19%) with ipilimumab. Despite a trend for increased PFS, anti-PD-1/ipilimumab combination did not significantly improve PFS (HR 0.85, p=0.35) or OS over anti-PD-1 (HR 1.30, p=0.16), potentially due to subsequent therapies and high rates of acquired resistance. No outcome differences were found between primary sites.

CONCLUSION

While the ORR to anti-PD-1/ipilimumab was significantly higher than anti-PD-1 and PFS numerically higher, in this retrospective cohort this benefit did not translate to improved OS. Future trials should specifically include patients with acral melanoma, to help determine the optimal management of this important melanoma subtype.

European consensus-based interdisciplinary guideline for melanoma. Part 2: Treatment - Update 2022

A unique collaboration of multidisciplinary experts from the European Dermatology Forum (EDF), the European Association of Dermato-Oncology (EADO), and the European Organization of Research and Treatment of Cancer (EORTC) was formed to make recommendations on cutaneous melanoma diagnosis and treatment, based on the systematic literature reviews and the experts' experience. Cutaneous melanomas are excised with one to 2-cm safety margins. Sentinel lymph node dissection shall be performed as a staging procedure in patients with tumor thickness ≥1.0 mm or ≥0.8 mm with additional histological risk factors, although there is as yet no clear survival benefit for this approach. Therapeutic decisions in stage III/IV patients should be primarily made by an interdisciplinary oncology team ("tumor board"). Adjuvant therapies can be proposed in stage III/completely resected stage IV patients and are primarily anti-PD-1, independent of mutational status, or alternatively dabrafenib plus trametinib for BRAF mutant patients. In distant metastases (stage IV), either resected or not, systemic treatment is always indicated. For first-line treatment particularly in BRAF wild-type patients, immunotherapy with PD-1 antibodies alone or in combination with CTLA-4 antibodies shall be considered. In stage IV melanoma with a BRAF-V600  E/K mutation, first-line therapy with BRAF/MEK inhibitors can be offered as an alternative to immunotherapy. In patients with primary resistance to immunotherapy and harboring a BRAF-V600  E/K mutation, this therapy shall be offered as second-line therapy. Systemic therapy in stage III/IV melanoma is a rapidly changing landscape, and it is likely that these recommendations may change in the near future.

Early tumor response assessment may avoid serious immune-related adverse events in nivolumab and ipilimumab combination therapy for stage IV melanoma

Nivolumab and ipilimumab combination therapy is one of the most promising treatments for patients with melanoma. However, this combination therapy is highly toxic and causes serious adverse events (SAEs) in more than half of the patients.

Prior Therapy With Pegylated-Interferon Alfa-2b Improves the Efficacy of Adjuvant Pembrolizumab in Resectable Advanced Melanoma

Combination immunotherapy can overcome the limited objective response rates of PD-1 blockade. Interferon alpha (IFN-α) has been proven to be effective in modulating immune responses and may enhance the clinical responses to PD-1 blockade. According to clinical practice guidelines, IFN-α was recommended as adjuvant therapy for stage IIB/C melanoma patients. However, the impact of prior IFN-α therapy on the efficacy of subsequent PD-1 blockade in melanoma has not been previously reported. Therefore, we performed a retrospective analysis for melanoma patients and addressed whether prior IFN-α therapy enhanced adjuvant pembrolizumab as later-line treatment. Fifty-six patients with resectable stage III/IV melanoma who received adjuvant therapy with pembrolizumab were retrospectively enrolled in this study. Notably, 25 patients received adjuvant pegylated IFN-α (PEG-IFN-α) in the prior line of treatment while 31 patients did not receive prior PEG-IFN-α therapy. Cox regression analysis showed that prior PEG-IFN-α therapy was associated with the efficacy of later-line adjuvant pembrolizumab (hazard ratio=0.37, 95% CI 0.16-0.89; P = 0.026). The recurrence rates after treatment with adjuvant pembrolizumab were significantly reduced in the prior PEG-IFN-α group (P < 0.001). The Kaplan-Meier analysis also showed that recurrence-free survival (RFS) after adjuvant pembrolizumab therapy was prolonged by prior PEG-IFN-α treatment (median RFS_Pem 8.5 months vs. 4.5 months; P = 0.0372). These findings indicated that prior PEG-IFN-α could enhance the efficacy of adjuvant pembrolizumab. The long-lasting effects of PEG-IFN-α provide a new rationale for designing combination or sequential immunotherapy.

Research Interest and Public Interest in Melanoma: A Bibliometric and Google Trends Analysis

INTRODUCTION

Melanoma is a severe skin cancer that metastasizes quickly. Bibliometric analysis can quantify hotspots of research interest. Google Trends can provide information to address public concerns.

METHODS

The top 15 most frequently cited articles on melanoma each year from 2015 to 2019, according to annual citations, were retrieved from the Web of Science database. Original articles, reviews, and research letters were included in this research. For the Google Trends analysis, the topic "Melanoma" was selected as the keyword. Online search data from 2004 to 2019 were collected. Four countries (New Zealand, Australia, the United States and the United Kingdom) were selected for seasonal analysis. Annual trends in relative search volume and seasonal variation were analyzed, and the top related topics and rising related topics were also selected and analyzed.

RESULTS

The top 15 most frequently cited articles each year were all original articles that focused on immunotherapy (n=8), omics (n=5), and the microbiome (n=2). The average relative search volume remained relatively stable across the years. The seasonal variation analysis revealed that the peak appeared in summer, and the valley appeared in winter. The diseases associated with or manifestations of melanoma, treatment options, risk factors, diagnostic tools, and prognosis were the topics in which the public was most interested. Most of the topics revealed by bibliometric and Google Trends analyses were consistent, with the exception of issues related to the molecular biology of melanoma.

CONCLUSION

This study revealed the trends in research interest and public interest in melanoma, which may pave the way for further research.