Surgical resection of metastatic melanoma in the era of immunotherapy and targeted therapy

Advancements in Melanoma Therapies: From Surgery to Immunotherapy

OPINION STATEMENT

Melanoma is defined as the most aggressive and deadly form of skin cancer. The treatment of melanoma depends on the disease stage, tumor location, and extent of its spread from its point of origin. Melanoma treatment has made significant advances, notably in the context of targeted and immunotherapies. Surgical resection is the main therapeutic option for earlystage melanoma, and it provides favourable outcomes. With disease metastasis, systemic treatments such as immunotherapy and targeted therapy become increasingly important. The identification of mutations that lead to melanoma has influenced treatment strategies. Targeted therapies focusing on these mutations offer improved response rates and fewer toxicities than conventional chemotherapy. Furthermore, developing immunotherapies, including checkpoint inhibitors and tumor-infiltrating lymphocyte (TIL) therapies, has demonstrated encouraging outcomes in effectively combating cancer cells. These therapeutic agents demonstrate superior effectiveness and a more tolerable side-effect profile, improving the quality of life for patients receiving treatment. The future of melanoma treatment may involve a multimodal approach consisting of a combination of surgery, targeted therapy, and immunotherapy adapted to each patient's profile. This approach may improve survival rates and health outcomes.

Surgery for Oligometastatic Pancreatic Cancer: Defining Biologic Resectability

Pancreatic ductal adenocarcinoma (PDAC) is most often metastatic at diagnosis. As systemic therapy continues to improve alongside advanced surgical techniques, the focus has shifted toward defining biologic, rather than technical, resectability. Several centers have reported metastasectomy for oligometastatic PDAC, yet the indications and potential benefits remain unclear. In this review, we attempt to define oligometastatic disease in PDAC and to explore the rationale for metastasectomy. We evaluate the existing evidence for metastasectomy in liver, peritoneum, and lung individually, assessing the safety and oncologic outcomes for each. Furthermore, we explore contemporary biomarkers of biological resectability in oligometastatic PDAC, including radiographic findings, biochemical markers (such as CA 19-9 and CEA), inflammatory markers (including neutrophil-to-lymphocyte ratio, C-reactive protein, and scoring indices), and liquid biopsy techniques. With careful consideration of existing data, we explore the concept of biologic resectability in guiding patient selection for metastasectomy in PDAC.

A case of metastatic melanoma in the liver mimicking colorectal cancer with synchronous liver metastasis

INTRODUCTION AND IMPORTANCE

Colorectal cancer (CRC) presenting with synchronous liver metastasis is relatively common, occurring in approximately 20 % of patients1. Herein we report an atypical case of a patient who presented with a new, obstructing colon mass with synchronous liver metastasis, biopsy proven to be malignant melanoma.

CASE PRESENTATION

An 81-year-old male presented to the hospital emergency department with abdominal pain, diarrhea, and 30-pound unintentional weight loss over the past 4 months. Investigations revealed an obstructing cecal mass with multiple large, hypodense hepatic masses suspicious for metastatic disease. A multidisciplinary evaluation ensued, and the decision was made to treat with palliative intent. The patient was surgically treated with a diverting stoma and an intraoperative biopsy of the hepatic masses demonstrated metastatic melanoma. The patient did report a remote history of malignant melanoma and underwent curative-intent resection a decade earlier. There was no evidence of a new primary cutaneous melanoma. A tentative plan for checkpoint inhibitor therapy was discussed, but his medical issues worsened, and the patient died before any anti-cancer therapy could be started.

CLINICAL DISCUSSION

The clinical picture of obstructing colon mass with synchronous liver masses most commonly represents a colon primary with synchronous liver metastasis. The capacity for melanoma to mimic other pathologies is unusual but has been described, with case reports describing metastasis to the eye, biliary hilum, liver, pancreas, colon, small bowel, and brain. This case serves as a good reminder that melanoma may mimic a variety of oncologic presentations, even after a very long disease-free interval.

CONCLUSION

Our patient suspected to have metastatic colon cancer was found instead to have metastatic melanoma, with significantly different therapeutic options and prognosis.

A novel PDPN antagonist peptide CY12-RP2 inhibits melanoma growth via Wnt/β-catenin and modulates the immune cells

BACKGROUND

Podoplanin (PDPN) is a highly conserved, mucin-type protein specific to the lymphatic system. Overexpression of PDPN is associated with the progression of various solid tumors, and plays an important roles in the tumor microenvironment by regulating the immune system. However, the role of PDPN-mediated signal activation in the progression of melanoma is still unknown.

METHODS

PDPN expression was first analyzed in 112 human melanoma tissue microarrays and melanoma cell lines. Functional experiments including proliferation, clone formation, migration, and metastasis were utilized to identify the suppressive effects of PDPN. The Ph.D.TM-12 Phage Display Peptide Library was used to obtain a PDPN antagonist peptide, named CY12-RP2. The immunofluorescence, SPR assay, and flow cytometry were used to identify the binding specificity of CY12-RP2 with PDPN in melanoma cells. Functional and mechanistic assays in vivo and in vitro were performed for discriminating the antitumor and immune activation effects of CY12-RP2.

RESULTS

PDPN was overexpressed in melanoma tissue and cells, and inhibited melanoma cells proliferation, migration, and metastasis by blocking the EMT and Wnt/β-catenin pathway. PDPN antagonistic peptide, CY12-RP2, could specifically bind with PDPN, suppressing melanoma various functions inducing apoptosis in both melanoma cells and 3D spheroids. CY12-RP2 also enhanced the anti-tumor capacity of PBMC, and inhibited melanoma cells growth both in xenografts and allogeneic mice model. Moreover, CY12-RP2 could inhibit melanoma lung metastasis, and abrogated the immunosuppressive effects of PDPN by increasing the proportion of CD3 + CD4 + T cells, CD3 + CD8 + T cells, CD49b + Granzyme B + NK cells, and CD11b + CD86 + M1-like macrophages and the levels of IL-1β, TNF-α, and IFN-γ.

CONCLUSIONS

This study has demonstrated the important role of PDPN in the progression of melanoma and formation of immunosuppressive environment, and provided a potential approach of treating melanoma using the novel CY12-RP2 peptide. In melanoma, PDPN is overexpressed in the cancer cells, and promotes melanoma cells growth and metastasis through activating the Wnt/β-catenin pathway. Treatment with the PDPN antagonistic peptide CY12-RP2 could not only inhibit the melanoma growth and metastasis both in vitro and in vivo through Wnt/β-catenin pathway blockade, but also abrogate the immunosuppressive effects of PDPN through modulating immune cells.

Ferroptosis as a promising therapeutic strategy for melanoma

Malignant melanoma (MM) is the most common and deadliest type of skin cancer and is associated with high mortality rates across all races and ethnicities. Although present treatment options combined with surgery provide short-term clinical benefit in patients and early diagnosis of non-metastatic MM significantly increases the probability of survival, no efficacious treatments are available for MM. The etiology and pathogenesis of MM are complex. Acquired drug resistance is associated with a pool prognosis in patients with advanced-stage MM. Thus, these patients require new therapeutic strategies to improve their treatment response and prognosis. Multiple studies have revealed that ferroptosis, a non-apoptotic form of regulated cell death (RCD) characterized by iron dependant lipid peroxidation, can prevent the development of MM. Recent studies have indicated that targeting ferroptosis is a promising treatment strategy for MM. This review article summarizes the core mechanisms underlying the development of ferroptosis in MM cells and its potential role as a therapeutic target in MM. We emphasize the emerging types of small molecules inducing ferroptosis pathways by boosting the antitumor activity of BRAFi and immunotherapy and uncover their beneficial effects to treat MM. We also summarize the application of nanosensitizer-mediated unique dynamic therapeutic strategies and ferroptosis-based nanodrug targeting strategies as therapeutic options for MM. This review suggests that pharmacological induction of ferroptosis may be a potential therapeutic target for MM.

A comprehensive review on novel targeted therapy methods and nanotechnology-based gene delivery systems in melanoma

Melanoma, a malignant form of skin cancer, has been swiftly increasing in recent years. Although there have been significant advancements in clinical treatment underlying a well-understanding of melanoma-susceptible genes and the molecular basis of melanoma pathogenesis, the permanency of response to therapy is frequently constrained by the emergence of acquired resistance and systemic toxicity. Conventional therapies, including surgical resection, chemotherapy, radiotherapy, and immunotherapy, have already been used to treat melanoma and are dependent on the cancer stage. Nevertheless, ineffective side effects and the heterogeneity of tumors pose major obstacles to the therapeutic treatment of malignant melanoma through such strategies. In light of this, advanced therapies including nucleic acid therapies (ncRNA, aptamers), suicide gene therapies, and gene therapy using tumor suppressor genes, have lately gained immense attention in the field of cancer treatment. Furthermore, nanomedicine and targeted therapy based on gene editing tools have been applied to the treatment of melanoma as potential cancer treatment approaches nowadays. Indeed, nanovectors enable delivery of the therapeutic agents into the tumor sites by passive or active targeting, improving therapeutic efficiency and minimizing adverse effects. Accordingly, in this review, we summarized the recent findings related to novel targeted therapy methods as well as nanotechnology-based gene systems in melanoma. We also discussed current issues along with potential directions for future research, paving the way for the next-generation of melanoma treatments.

Margin-Negative en Bloc Resection of a Large Retroperitoneal Melanoma Including Reconstruction of the Infra-renal Inferior Vena Cava

The management and outcomes for patients with metastatic melanoma have been revolutionized by immunotherapy. This case report highlights the role of surgery as an adjuvant to systemic therapies when there is oligoprogressive disease. We describe a 74-year-old man with metastatic melanoma who initially had a complete radiographic response after dual agent immunotherapy but subsequently developed a large metastasis in the retroperitoneum. After multidisciplinary discussion, he underwent margin negative resection that required en bloc segmental resection of the infra-renal inferior vena cava. To our knowledge, this is the first reported resection of a melanoma metastasis in this location.

Targeting the epigenome in malignant melanoma: Facts, challenges and therapeutic promises

Malignant melanoma is the most lethal type of skin cancer with high rates of mortality. Although current treatment options provide a short-clinical benefit, acquired-drug resistance highlights the low 5-year survival rate among patients with advanced stage of the disease. In parallel, the involvement of an aberrant epigenetic landscape, (e.g., alterations in DNA methylation patterns, histone modifications marks and expression of non-coding RNAs), in addition to the genetic background, has been also associated with the onset and progression of melanoma. In this review article, we report on current therapeutic options in melanoma treatment with a focus on distinct epigenetic alterations and how their reversal, by specific drug compounds, can restore a normal phenotype. In particular, we concentrate on how single and/or combinatorial therapeutic approaches have utilized epigenetic drug compounds in being effective against malignant melanoma. Finally, the role of deregulated epigenetic mechanisms in promoting drug resistance to targeted therapies and immune checkpoint inhibitors is presented leading to the development of newly synthesized and/or improved drug compounds capable of targeting the epigenome of malignant melanoma.

The Fatty Acid and Protein Profiles of Circulating CD81-Positive Small Extracellular Vesicles Are Associated with Disease Stage in Melanoma Patients

Simple Summary

Early detection of cutaneous melanoma is the key to increasing survival and proper therapeutic adjustment, especially in stages II–IV. We investigated whether the fatty acid (FA) and protein compositions of small extracellular vesicles (sEV) expressing CD81, derived from the plasma of stage 0–I, II and III–IV melanoma patients, could reflect disease stage. Results showed a higher content of FA and differences in C18:0/C18:1 ratio, a marker of cell membrane fluidity, that distinguished patients’ CD81sEV from those of healthy donors (HD). By proteomic analysis (identifier PXD024434) we identified significant increases in CD14, PON1, PON3 and APOA5 in stage II CD81sEV compared to HD. In stage III–IV, CD81sEV’ RAP1B expression was decreased. These stage-related signatures may support the potential of sEV to provide information for early diagnosis, prediction of metastatic behavior, treatment and follow-up of melanoma patients.

Abstract

The early detection of cutaneous melanoma, a potentially lethal cancer with rising incidence, is fundamental to increasing survival and therapeutic adjustment. In stages II–IV especially, additional indications for adjuvant therapy purposes after resection and for treatment of metastatic patients are urgently needed. We investigated whether the fatty acid (FA) and protein compositions of small extracellular vesicles (sEV) derived from the plasma of stage 0–I, II and III–IV melanoma patients (n = 38) could reflect disease stage. The subpopulation of sEV expressing CD81 EV marker (CD81sEV) was captured by an ad hoc immune affinity technique from plasma depleted of large EV. Biological macromolecules were investigated by gas chromatography and mass spectrometry in CD81sEV. A higher content of FA was detectable in patients with respect to healthy donors (HD). Moreover, a higher C18:0/C18:1 ratio, as a marker of cell membrane fluidity, distinguished early (stage 0–I) from late (III–IV) stages’ CD81sEV. Proteomics detected increases in CD14, PON1, PON3 and APOA5 exclusively in stage II CD81sEV, and RAP1B was decreased in stage III–IV CD81sEV, in comparison to HD. Our results suggest that stage dependent alterations in CD81sEV’ FA and protein composition may occur early after disease onset, strengthening the potential of circulating sEV as a source of discriminatory information for early diagnosis, prediction of metastatic behavior and following up of melanoma patients.

Recognition, Staging, and Management of Melanoma

Melanoma accounts for approximately 1% of all skin cancers but contributes to almost all skin cancer deaths. The developing picture suggests that melanoma phenotypes are driven by epigenetic mechanisms that reflect a complex interplay between genotype and environment. Furthermore, the growing consensus is that current classification standards, notwithstanding pertinent clinical history and appropriate biopsy, fall short of capturing the vast complexity of the disease. This article summarizes the current understanding of the clinical picture of melanoma, with a focus on the tremendous breakthroughs in molecular classification and therapeutics.

Overcoming Immune Evasion in Melanoma

Melanoma is the most aggressive and dangerous form of skin cancer that develops from transformed melanocytes. It is crucial to identify melanoma at its early stages, in situ, as it is "curable" at this stage. However, after metastasis, it is difficult to treat and the five-year survival is only 25%. In recent years, a better understanding of the etiology of melanoma and its progression has made it possible for the development of targeted therapeutics, such as vemurafenib and immunotherapies, to treat advanced melanomas. In this review, we focus on the molecular mechanisms that mediate melanoma development and progression, with a special focus on the immune evasion strategies utilized by melanomas, to evade host immune surveillances. The proposed mechanism of action and the roles of immunotherapeutic agents, ipilimumab, nivolumab, pembrolizumab, and atezolizumab, adoptive T- cell therapy plus T-VEC in the treatment of advanced melanoma are discussed. In this review, we implore that a better understanding of the steps that mediate melanoma onset and progression, immune evasion strategies exploited by these tumor cells, and the identification of biomarkers to predict treatment response are critical in the design of improved strategies to improve clinical outcomes for patients with this deadly disease.

Prognostic factors for pulmonary metastasectomy in malignant melanoma: size matters

OBJECTIVES

Pulmonary metastasectomy for malignant melanoma requires an individualized therapeutic decision. Due to recently developed novel treatment options, the prognosis of patients with melanoma has improved significantly. Validated prognostic factors that identify patients who are most likely to benefit from metastasectomy are urgently needed.

METHODS

We retrospectively reviewed all consecutive patients with melanoma undergoing complete pulmonary metastasectomy between January 2010 and December 2016. The impact of age, sex, extrapulmonary metastases, preoperative systemic therapy, number of metastases, laterality and largest diameter of metastasis on survival after metastasectomy was analysed.

RESULTS

A total of 29 male and 32 female patients were included in the study. The median follow-up time was 25.6 months. The mean number of resected metastases was 1.7 ± 1.1 (range 1-5). Ten patients had repetitive pulmonary metastasectomies. The median survival time was 31.3 months with a 2-year survival rate of 54%. Bilateral metastases or multiple nodules were not associated with a significantly decreased overall survival rate after metastasectomy. Shorter overall survival times were observed in male patients [hazard ratio (HR) 2.9, 95% confidence interval (CI) 1.42-5.92; P = 0.0035] and in patients with nodules larger than 2 cm (HR 3.18, 95% CI 1.45-6.98; P = 0.004). In multivariable analysis, both gender and tumour size remained significant independent prognostic factors.

CONCLUSIONS

Excellent overall survival rates after pulmonary metastasectomy for melanoma metastases were observed in patients with a metastatic diameter less than 2 cm and in female patients. In view of improved long-term outcome due to novel treatment options, the selection of patients for pulmonary metastasectomy based on prognostic factors will become increasingly important.

A Novel Nomogram and Risk Classification System Predicting the Cancer-Specific Mortality of Patients with Initially Diagnosed Metastatic Cutaneous Melanoma

BACKGROUND

Cutaneous melanoma and distant organ metastasis has varying outcomes. Considering all prognostic indicators in a prediction model might assist in selecting cases who could benefit from a personalized therapy strategy.

OBJECTIVE

This study aimed to develop and validate a prognostic model for patients with metastatic melanoma.

METHODS

A total of 1535 cases diagnosed with metastatic cutaneous melanoma (stage IV) were identified from the Surveillance, Epidemiology, and End Results database. Patients were randomly divided into the training (n = 1023) and validation (n = 512) cohorts. A prognostic nomogram was established based predominantly on results from the competing-risk regression model for predicting cancer-specific death (CSD). The area under the time-dependent receiver operating characteristic curve (AUC), calibration curves, and decision curve analyses (DCAs) were used to evaluate the nomogram.

RESULTS

No significant differences were observed in the clinical characteristics between the training and validation cohorts. In the training cohort, patient-, tumor-, and treatment-related predictors of CSD for metastatic melanoma included age, sex, race, marital status, insurance, American Joint Committee on Cancer T and N stage, number of metastatic organs, surgical treatment, and chemotherapy. All these factors were used for nomogram construction. The time-dependent AUC values of the training and validation cohorts suggested a favorable performance and discrimination of the nomogram. The 6-, 12-, and 18-month AUC values were 0.706, 0.700, and 0.706 in the training cohort, and 0.702, 0.670, and 0.656 in the validation cohort, respectively. The calibration curves for the probability of death at 6, 12, and 18 months showed acceptable agreement between the values predicted by the nomogram and the observed outcomes in both cohorts. DCA curves showed good positive net benefits in the prognostic model among most of the threshold probabilities at different time points (death at 6, 12, and 18 months). Based on the total nomogram scores of each case, all patients were divided into the low-risk (n = 511), intermediate-risk (n = 512), and high-risk (n = 512) groups, and the risk classification could identify cases with a high risk of death in both cohorts.

CONCLUSIONS

A predictive nomogram and a corresponding risk classification system for CSD in patients with metastatic melanoma were developed in this study, which may assist in patient counseling and in guiding clinical decision making for cases with metastatic melanoma.

Prognostic significance of distant metastasis-free interval in patients with relapsed melanoma treated with BRAF with or without MEK inhibitors

This retrospective cohort study assessed the prognostic significance of distant metastasis-free interval (DMFI) in patients with relapsed BRAF-mutant melanoma treated with BRAF with or without MEK inhibitors (BRAFi ± MEKi). Patients with a DMFI of up to 24 months were compared with those with DMFI of more than 24 months, with regard to their postrelapse progression-free survival (PR-PFS) and overall survival (PR-OS). In total, 109 patients were included in the study. Median DMFI was 25.3 (range: 3.4-188.2) months. Median PR-PFS in patients with DMFI of more than 24 months was 7.9 months [95% confidence interval (CI): 6.2-9.7] compared with 5.4 (95% CI: 4.2-6.7) months of those with shorter DMFI (P = 0.016). Median PR-OS was 15.6 months (95% CI: 13.6-17.6) in patients with DMFI of more than 24 months and 12.0 months (95% CI: 9.0-15.0) with DMFI of up to 24 months (P = 0.289). Multivariate Cox regression analysis showed that DMFI was independently and strongly associated with improved PR-PFS (adjusted hazard ratio = 3.21, 95% CI: 1.78-5.77, ≤ 24 vs. > 24 months) and longer PR-OS (adjusted hazard ratio: 2.09, 95% CI: 1.15-3.80, ≤ 24 vs. > 24 months). The present cohort study is one of the first to confirm the association of DMFI of more than 24 months with an indolent disease course, as shown by longer PR-PFS and PR-OS, in patients with relapsed stage IV melanoma treated by BRAF inhibitor/MEK inhibitor.