Acral melanoma: clinical advances and hope for the future.

Acral melanoma is a rare subtype of melanoma with unique histologic and biologic characteristics. Given its relative rarity compared with nonacral cutaneous melanoma, acral melanoma has been understudied and underrepresented in modern-day prospective clinical trials that have shaped the contemporary management of advanced cutaneous melanoma. Therefore, treatment principles for advanced acral melanoma are mostly derived from retrospective analyses or extrapolated from data largely based on nonacral cutaneous melanoma. Further studies are warranted to evaluate the efficacy of systemic immune and targeted molecular therapies, and to identify molecular targets for patients with advanced acral melanoma.

Current and future approaches in the surgical management of T3b/T4 primary and locoregionally advanced melanoma.

Currently accepted principles of surgical management-margin width, use of sentinel node biopsy, performance of radical node dissections for node-positive cases-and some aspects of postoperative management (use of radiation for desmoplastic melanoma primaries and for clinically node-positive disease) will change in the future with the potential widespread adoption of adjuvant and neoadjuvant therapies.

Therapeutic Value of Sentinel Lymph Node Biopsy in Patients With Melanoma: A Randomized Clinical Trial.

Importance: Sentinel lymph node (SLN) biopsy is a standard staging procedure for cutaneous melanoma. Regional disease control is a clinically important therapeutic goal of surgical intervention, including nodal surgery. Objective: To determine how frequently SLN biopsy without completion lymph node dissection (CLND) results in long-term regional nodal disease control in patients with SLN metastases. Design, Setting, and Participants: The second Multicenter Selective Lymphadenectomy Trial (MSLT-II), a prospective multicenter randomized clinical trial, randomized participants with SLN metastases to either CLND or nodal observation. The current analysis examines observation patients with regard to regional nodal recurrence. Trial patients were aged 18 to 75 years with melanoma metastatic to SLN(s). Data were collected from December 2004 to April 2019, and data were analyzed from July 2020 to January 2022. Interventions: Nodal observation with ultrasonography rather than CLND. Main Outcomes and Measures: In-basin nodal recurrence. Results: Of 823 included patients, 479 (58.2%) were male, and the mean (SD) age was 52.8 (13.8) years. Among 855 observed basins, at 10 years, 80.2% (actuarial; 95% CI, 77-83) of basins were free of nodal recurrence. By univariable analysis, freedom from regional nodal recurrence was associated with age younger than 50 years (hazard ratio [HR], 0.49; 95% CI, 0.34-0.70; P < .001), nonulcerated melanoma (HR, 0.36; 95% CI, 0.36-0.49; P < .001), thinner primary melanoma (less than 1.5 mm; HR, 0.46; 95% CI, 0.27-0.78; P = .004), axillary basin (HR, 0.61; 95% CI, 0.44-0.86; P = .005), fewer positive SLNs (1 vs 3 or more; HR, 0.32; 95% CI, 0.14-0.75; P = .008), and SLN tumor burden (measured by diameter less than 1 mm [HR, 0.39; 95% CI, 0.26-0.60; P = .001] or less than 5% area [HR, 0.36; 95% CI, 0.24-0.54; P < .001]). By multivariable analysis, younger age (HR, 0.57; 95% CI, 0.39-0.84; P = .004), thinner primary melanoma (HR, 0.40; 95% CI, 0.22-0.70; P = .002), axillary basin (HR, 0.55; 95% CI, 0.31-0.96; P = .03), SLN metastasis diameter less than 1 mm (HR, 0.52; 95% CI, 0.33-0.81; P = .007), and area less than 5% (HR, 0.58; 95% CI, 0.38-0.88; P = .01) were associated with basin control. When looking at the identified risk factors of age (50 years or older), ulceration, Breslow thickness greater than 3.5 mm, nonaxillary basin, and tumor burden of maximum diameter of 1 mm or greater and/or metastasis area of 5% or greater and excluding missing value cases, basin disease-free rates at 5 years were 96% (95% CI, 88-100) for patients with 0 risk factors, 89% (95% CI, 82-96) for 1 risk factor, 86% (95% CI, 80-93) for 2 risk factors, 80% (95% CI, 71-89) for 3 risk factors, 61% (95% CI, 48-74) for 4 risk factors, and 54% (95% CI, 36-72) for 5 or 6 risk factors. Conclusions and Relevance: This randomized clinical trial was the largest prospective evaluation of long-term regional basin control in patients with melanoma who had nodal observation after removal of a positive SLN. SLN biopsy without CLND cleared disease in the affected nodal basin in most patients, even those with multiple risk factors for in-basin recurrence. In addition to its well-validated value in staging, SLN biopsy may also be regarded as therapeutic in some patients. Trial Registration: ClinicalTrials.gov Identifier: NCT00297895.

Emerging Therapies in the Treatment of Advanced Melanoma.

Great strides in immunotherapy and targeted therapy have revolutionized the management of previously devastating, advanced melanomas. Although these subfields continue to progress, novel approaches in intratumoral oncolytic therapy, adoptive cell therapy, and vaccine therapies are being developed as adjuncts or alternatives. Cytokines, meanwhile, are seeing a resurgence as a viable option as well. The array of effective agents will, in the next few years, provide options for therapy not only in the adjuvant or unresectable settings but also in the neoadjuvant settings. Perhaps, too, in earlier stage melanomas.

Evidence-Based Clinical Practice Guideline: Reconstruction after Skin Cancer Resection.

SUMMARY: A multi-disciplinary work group involving stakeholders from various backgrounds and societies was convened to develop guidelines for the management of reconstruction after skin cancer resection. The goal was to identify areas of common ground and provide evidence-based recommendations to improve patient care. Given the heterogeneity of reconstructive techniques and clinical scenarios, investigation centered around common elements in the process. In some cases, a distinction was made between treatment options in the office-based setting as opposed to those in the facility setting. A systematic literature review was performed, and an established appraisal process was used to rate the quality of relevant scientific research (Grading of Recommendations Assessment, Development, and Evaluation methodology). Final recommendations are related to concepts concerning the timing of reconstruction, management of anticoagulation, use of antibiotics, methods of pain control, and follow-up assessment. At times, there was insufficient evidence to make high-level recommendations. The literature analysis highlights the need for additional methodologically robust studies in this area, to help guide clinical practice.

Evidence-based clinical practice guideline: Reconstruction after skin cancer resection.

A multi-disciplinary work group involving stakeholders from various backgrounds and societies was convened to develop guidelines for the management of reconstruction after skin cancer resection. The goal was to identify areas of common ground and provide evidence-based recommendations to improve patient care. Given the heterogeneity of reconstructive techniques and clinical scenarios, investigation centered around common elements in the process. In some cases, a distinction was made between treatment options in the office-based setting as opposed to those in the facility setting. A systematic literature review was performed, and an established appraisal process was used to rate the quality of relevant scientific research (Grading of Recommendations Assessment, Development, and Evaluation methodology). Final recommendations are related to concepts concerning the timing of reconstruction, management of anticoagulation, use of antibiotics, methods of pain control, and follow-up assessment. At times, there was insufficient evidence to make high-level recommendations. The literature analysis highlights the need for additional methodologically robust studies in this area, to help guide clinical practice.

Evidence-Based Clinical Practice Guideline: Reconstruction after Skin Cancer Resection.

SUMMARY: A multi-disciplinary work group involving stakeholders from various backgrounds and societies was convened to develop guidelines for the management of reconstruction after skin cancer resection. The goal was to identify areas of common ground and provide evidence-based recommendations to improve patient care. Given the heterogeneity of reconstructive techniques and clinical scenarios, investigation centered around common elements in the process. In some cases, a distinction was made between treatment options in the office-based setting as opposed to those in the facility setting. A systematic literature review was performed, and an established appraisal process was used to rate the quality of relevant scientific research (Grading of Recommendations Assessment, Development, and Evaluation methodology). Final recommendations are related to concepts concerning the timing of reconstruction, management of anticoagulation, use of antibiotics, methods of pain control, and follow-up assessment. At times, there was insufficient evidence to make high-level recommendations. The literature analysis highlights the need for additional methodologically robust studies in this area, to help guide clinical practice.

Neoadjuvant Pembrolizumab and High-Dose IFNα-2b in Resectable Regionally Advanced Melanoma.

PURPOSE: Neoadjuvant immunotherapy may improve the clinical outcome of regionally advanced operable melanoma and allows for rapid clinical and pathologic assessment of response. We examined neoadjuvant pembrolizumab and high-dose IFNα-2b (HDI) therapy in patients with resectable advanced melanoma. PATIENTS AND METHODS: Patients with resectable stage III/IV melanoma were treated with concurrent pembrolizumab 200 mg i.v. every 3 weeks and HDI 20 MU/m2/day i.v., 5 days per week for 4 weeks, then 10 MU/m2/day subcutaneously 3 days per week for 2 weeks. Definitive surgery followed, as did adjuvant combination immunotherapy, completing a year of treatment. Primary endpoint was safety of the combination. Secondary endpoints included overall response rate (ORR), pathologic complete response (pCR), recurrence-free survival (RFS), and overall survival (OS). Blood samples for correlative studies were collected throughout. Tumor tissue was assessed by IHC and flow cytometry at baseline and at surgery. RESULTS: A total of 31 patients were enrolled, and 30 were evaluable. At data cutoff (October 2, 2019), median follow-up for OS was 37.87 months (range, 33.2-43.47). Median OS and RFS were not reached. Radiographic ORR was 73.3% [95% confidence interval (CI): 55.5-85.8], with a 43% (95% CI: 27.3-60.1) pCR rate. None of the patients with a pCR have had a recurrence. HDI and pembrolizumab were discontinued in 73% and 43% of patients, respectively. Correlative analyses suggested that intratumoral PD-1/PD-L1 interaction and HLA-DR expression are associated with pCR (P = 0.002 and P = 0.008, respectively). CONCLUSIONS: Neoadjuvant concurrent HDI and pembrolizumab demonstrated promising clinical activity despite high rates of treatment discontinuation. pCR is a prognostic indicator.See related commentary by Menzies et al., p. 4133.

Defining best practices for tissue procurement in immuno-oncology clinical trials: consensus statement from the Society for Immunotherapy of Cancer Surgery Committee.

Immunotherapy is now a cornerstone for cancer treatment, and much attention has been placed on the identification of prognostic and predictive biomarkers. The success of biomarker development is dependent on accurate and timely collection of biospecimens and high-quality processing, storage and shipping. Tumors are also increasingly used as source material for the generation of therapeutic T cells. There have been few guidelines or consensus statements on how to optimally collect and manage biospecimens and source material being used for immunotherapy and related research. The Society for Immunotherapy of Cancer Surgery Committee has brought together surgical experts from multiple subspecialty disciplines to identify best practices and to provide consensus on how best to access and manage specific tissues for immuno-oncology treatments and clinical investigation. In addition, the committee recommends early integration of surgeons and other interventional physicians with expertise in biospecimen collection, especially in clinical trials, to optimize the quality of tissue and the validity of correlative clinical studies in cancer immunotherapy.

Indocyanine green and fluorescence lymphangiography for sentinel node identification in patients with melanoma.

BACKGROUND: Infrared fluorescence imaging with indocyanine green (ICG) is a novel method for sentinel node localization. Our objective was to assess ICG and fluorescence imaging for preoperative and intraoperative utility. METHODS: 87 eligible patients participated in this prospective study. All patients received injection of ICG dye in addition to both methylene blue and 99mTc. Each sentinel node was assessed for the presence of each dye. RESULTS: ICG was visible prior to incision in 44% of subjects. 99mTc identified a mean of 1.89 SLN per patient. ICG identified a mean of 1.87 SLN while methylene blue (MB) dye identified a mean of 0.71 SLN. 99mTc and ICG identified the same number of sentinel nodes per patient (P = .73) while methylene blue was inferior in its ability to localize sentinel nodes (P < .001). CONCLUSION: Our findings indicate that ICG/fluorescence imaging has limited ability to identify the nodal basin preoperatively, but is equivalent to 99mTc for intraoperative identification of sentinel nodes and superior to MB.

Nanoliposomal delivery of cytosolic phospholipase A2 inhibitor arachidonyl trimethyl ketone for melanoma treatment.

Drug resistance and toxicity are major limitations of cancer treatment and frequently occurs during melanoma therapy. Nanotechnology can decrease drug resistance by improving drug delivery, with limited toxicity. This study details the development of nanoparticles containing arachidonyl trifluoromethyl ketone (ATK), a cytosolic phospholipase A2 inhibitor, which can inhibit multiple key pathways responsible for the development of recurrent resistant disease. Free ATK is toxic, limiting its efficacy as a therapeutic agent. Hence, a novel nanoliposomal delivery system called NanoATK was developed, which loads 61.7% of the compound and was stable at 4oC for 12 weeks. The formulation decreased toxicity-enabling administration of higher doses, which was more effective at inhibiting melanoma cell growth compared to free-ATK. Mechanistically, NanoATK decreased cellular proliferation and triggered apoptosis to inhibit melanoma xenograft tumor growth without affecting animal weight. Functionally, it inhibited the cPLA2, AKT, and STAT3 pathways. Our results suggest the successful preclinical development of a unique nanoliposomal formulation containing ATK for the treatment of melanoma.

Moving Synergistically Acting Drug Combinations to the Clinic by Comparing Sequential versus Simultaneous Drug Administrations.

Drug combinations acting synergistically to kill cancer cells have become increasingly important in melanoma as an approach to manage the recurrent resistant disease. Protein kinase B (AKT) is a major target in this disease but its inhibitors are not effective clinically, which is a major concern. Targeting AKT in combination with WEE1 (mitotic inhibitor kinase) seems to have potential to make AKT-based therapeutics effective clinically. Since agents targeting AKT and WEE1 have been tested individually in the clinic, the quickest way to move the drug combination to patients would be to combine these agents sequentially, enabling the use of existing phase I clinical trial toxicity data. Therefore, a rapid preclinical approach is needed to evaluate whether simultaneous or sequential drug treatment has maximal therapeutic efficacy, which is based on a mechanistic rationale. To develop this approach, melanoma cell lines were treated with AKT inhibitor AZD5363 [4-amino-N-[(1S)-1-(4-chlorophenyl)-3-hydroxypropyl]-1-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidine-4-carboxamide] and WEE1 inhibitor AZD1775 [2-allyl-1-(6-(2-hydroxypropan-2-yl)pyridin-2-yl)-6-((4-(4-methylpiperazin-1-yl)phenyl)amino)-1H-pyrazolo[3,4-d]pyrimidin-3(2H)-one] using simultaneous and sequential dosing schedules. Simultaneous treatment synergistically reduced melanoma cell survival and tumor growth. In contrast, sequential treatment was antagonistic and had a minimal tumor inhibitory effect compared with individual agents. Mechanistically, simultaneous targeting of AKT and WEE1 enhanced deregulation of the cell cycle and DNA damage repair pathways by modulating transcription factors p53 and forkhead box M1, which was not observed with sequential treatment. Thus, this study identifies a rapid approach to assess the drug combinations with a mechanistic basis for selection, which suggests that combining AKT and WEE1 inhibitors is needed for maximal efficacy.

Completion Dissection or Observation for Sentinel-Node Metastasis in Melanoma.

BACKGROUND: Sentinel-lymph-node biopsy is associated with increased melanoma-specific survival (i.e., survival until death from melanoma) among patients with node-positive intermediate-thickness melanomas (1.2 to 3.5 mm). The value of completion lymph-node dissection for patients with sentinel-node metastases is not clear. METHODS: In an international trial, we randomly assigned patients with sentinel-node metastases detected by means of standard pathological assessment or a multimarker molecular assay to immediate completion lymph-node dissection (dissection group) or nodal observation with ultrasonography (observation group). The primary end point was melanoma-specific survival. Secondary end points included disease-free survival and the cumulative rate of nonsentinel-node metastasis. RESULTS: Immediate completion lymph-node dissection was not associated with increased melanoma-specific survival among 1934 patients with data that could be evaluated in an intention-to-treat analysis or among 1755 patients in the per-protocol analysis. In the per-protocol analysis, the mean (±SE) 3-year rate of melanoma-specific survival was similar in the dissection group and the observation group (86±1.3% and 86±1.2%, respectively; P=0.42 by the log-rank test) at a median follow-up of 43 months. The rate of disease-free survival was slightly higher in the dissection group than in the observation group (68±1.7% and 63±1.7%, respectively; P=0.05 by the log-rank test) at 3 years, based on an increased rate of disease control in the regional nodes at 3 years (92±1.0% vs. 77±1.5%; P<0.001 by the log-rank test); these results must be interpreted with caution. Nonsentinel-node metastases, identified in 11.5% of the patients in the dissection group, were a strong, independent prognostic factor for recurrence (hazard ratio, 1.78; P=0.005). Lymphedema was observed in 24.1% of the patients in the dissection group and in 6.3% of those in the observation group. CONCLUSIONS: Immediate completion lymph-node dissection increased the rate of regional disease control and provided prognostic information but did not increase melanoma-specific survival among patients with melanoma and sentinel-node metastases. (Funded by the National Cancer Institute and others; MSLT-II ClinicalTrials.gov number, NCT00297895 .).

Improved survival and complete response rates in patients with advanced melanoma treated with concurrent ipilimumab and radiotherapy versus ipilimumab alone.

There is a growing body of evidence supporting the synergistic roles of radiotherapy and immunotherapy in the treatment of malignancy. Published case studies of the abscopal effect have been reported with the use of ipilimumab and radiotherapy in metastatic melanoma, but evidence supporting the routine use of this combination of therapy is limited. We conducted a retrospective analysis to evaluate patients treated with ipilimumab for advanced melanoma at a single institution from May 2011 to June 2015. Patients were grouped into those who had received concurrent radiotherapy while on ipilimumab (Ipi-RT), and those who did not. We then evaluated the treatment response following completion of ipilimumab. A total of 101 patients received ipilimumab in the prespecified time frame. 70 received Ipi-RT and 31 received ipilimumab without concurrent radiotherapy. Median overall survival (OS) was significantly increased in the concurrent Ipi-RT arm at 19 months vs. 10 months for ipilimumab alone (p = 0.01). Median progression free survival (PFS) was marginally increased in the Ipi-RT group compare with the ipilimumab alone group (5 months vs. 3 months, p = 0.20). Rates of complete response (CR) were significantly increased in the Ipi-RT group vs. ipilimumab alone (25.7% vs. 6.5%; p = 0.04), and rates of overall response (OR) in the groups were 37.1% vs. 19.4% (p = 0.11). No increase in toxicities was observed in the Ipi-RT group compare with ipilimumab alone. Prospective trials are needed to further clarify the role of radiotherapy with ipilimumab, but these encouraging preliminary observations suggest that this combination can induce more durable responses to immunotherapy.

Orbital Expansion for Congenital Anophthalmia May Be Achievable in Infancy But Not in Childhood.

BACKGROUND: Congenital anophthalmia is a rare anomaly that results in micro-orbitism and craniofacial microsomia. Treatment with static conformers is labor-intensive and provides minimal stimulation for orbital growth that requires eventual reconstruction with orbital osteotomies after skeletal maturity. METHODS: A protocol for the treatment of congenital anophthalmia is presented. Patients underwent a preoperative low-dose radiation computed tomography (CT) scan of the facial bones to assess orbital volume. An intraorbital expander was placed and was filled on a monthly basis. Quantitative changes in the affected and unaffected orbits were assessed by a repeat CT scan obtained 1 year postoperatively. RESULTS: Two patients with left unilateral congenital anophthalmia were prospectively followed. In a 4-month-old, the affected orbital width and height increased by 171.6% and 116.7% respectively compared with the unaffected orbit. In a 4-year-old, the affected orbital width increased by 36.1% but the height decreased by 35.3% compared with the unaffected orbit. At 18 months follow-up, no complications, ruptures, infections, or extrusions have been observed. CONCLUSIONS: Our results support that accelerated expansion can be achieved in a 4-month-old orbit reversing the effects of anophthalmia. However, in a 4-year-old, minimal growth was observed. The lack of accelerated growth in this study may be explained by synostosis of the orbital sutures. As such, expansion should be initiated at the earliest age possible. Further longitudinal study is ongoing to determine if sustained catch-up growth will obviate or reduce the complexity of a secondary correction.

Malignant melanoma-The cradle of anti-neoplastic immunotherapy.

One of the defining characteristics of the malignant phenotype is the ability to evade the host immune system. Immunotherapy as a treatment modality represents a new dawn in the way we think about the treatment of a variety of malignancies. The story of immunotherapy traces its roots to its relationship with malignant melanoma. In this article, we review the intertwined history of immunotherapy and melanoma, including the early significant history, a discussion on immune mechanisms, resistance, local and systemic immunotherapeutic modalities, and speculate on possible novel future treatment options.

Characterization and Management of Hedgehog Pathway Inhibitor-Related Adverse Events in Patients With Advanced Basal Cell Carcinoma.

Abnormal activation of hedgehog pathway signaling is a key driver in the pathogenesis of basal cell carcinoma (BCC). Vismodegib, a first-in-class small-molecule inhibitor of hedgehog pathway signaling, is approved by regulatory authorities for the treatment of adults who have metastatic BCC or locally advanced BCC that has recurred after surgery, or who are not candidates for surgery and who are not candidates for radiation. A second inhibitor, sonidegib, was also recently approved for the same patient group with locally advanced BCC. Adverse events (AEs) commonly observed in hedgehog pathway inhibitor (HPI)-treated patients include muscle spasms, ageusia/dysgeusia, alopecia, weight loss, and asthenia (fatigue). These AEs are thought to be mechanistically related to inhibition of the hedgehog pathway in normal tissue. Although the severity of the majority of AEs associated with HPIs is grade 1-2, the long-term nature of these AEs can lead to decreased quality of life, treatment interruption, and in some cases discontinuation, all of which might affect clinical outcome. The incidence, clinical presentation, putative mechanisms, and management strategies for AEs related to HPIs in advanced BCC are described. These observations represent the first step toward the development of mechanism-based preventive and management strategies. Knowledge of these AEs will allow health care professionals to provide appropriate counseling and supportive care interventions, all of which will contribute to improved quality of life and optimal benefit from therapy. IMPLICATIONS FOR PRACTICE: The hedgehog pathway inhibitors (HPIs) vismodegib and sonidegib represent a therapeutic breakthrough for patients with advanced basal cell carcinoma. However, the nature of the low-grade adverse events (AEs) commonly observed in HPI-treated patients, including muscle spasms, ageusia/dysgeusia, alopecia, weight loss, and fatigue, can impact clinical outcomes as a result of decreased quality of life and treatment discontinuation. The incidence, clinical presentation, putative mechanisms, and management strategies for AEs related to administration of HPIs are described, with the goal of enabling health care professionals to provide appropriate counseling and supportive care interventions to their patients.

Macrophage-tumor cell fusions from peripheral blood of melanoma patients.

BACKGROUND: While the morbidity and mortality from cancer are largely attributable to its metastatic dissemination, the integral features of the cascade are not well understood. The widely accepted hypothesis is that the primary tumor microenvironment induces the epithelial-to-mesenchymal transition in cancer cells, facilitating their escape into the bloodstream, possibly accompanied by cancer stem cells. An alternative theory for metastasis involves fusion of macrophages with tumor cells (MTFs). Here we culture and characterize apparent MTFs from blood of melanoma patients. METHODS: We isolated enriched CTC populations from peripheral blood samples from melanoma patients, and cultured them. We interrogated these cultured cells for characteristic BRAF mutations, and used confocal microscopy for immunophenotyping, motility, DNA content and chromatin texture analyses, and then conducted xenograft studies using nude mice. FINDINGS: Morphologically, the cultured MTFs were generally large with many pseudopod extensions and lamellipodia. Ultrastructurally, the cultured MTFs appeared to be macrophages. They were rich in mitochondria and lysosomes, as well as apparent melanosomes. The cultured MTF populations were all heterogeneous with regard to DNA content, containing aneuploid and/or high-ploidy cells, and they typically showed large sheets (and/or clumps) of cytoplasmic chromatin. This cytoplasmic DNA was found within heterogeneously-sized autophagic vacuoles, which prominently contained chromatin and micronuclei. Cultured MTFs uniformly expressed pan-macrophage markers (CD14, CD68) and macrophage markers indicative of M2 polarization (CD163, CD204, CD206). They also expressed melanocyte-specific markers (ALCAM, MLANA), epithelial biomarkers (KRT, EpCAM), as well as the pro-carcinogenic cytokine MIF along with functionally related stem cell markers (CXCR4, CD44). MTF cultures from individual patients (5 of 8) contained melanoma-specific BRAF activating mutations. Chromatin texture analysis of deconvoluted images showed condensed DNA (DAPI-intense) regions similar to focal regions described in stem cell fusions. MTFs were readily apparent in vivo in all human melanomas examined, often exhibiting even higher DNA content than the cultured MTFs. When cultured MTFs were transplanted subcutaneously in nude mice, they disseminated and produced metastatic lesions at distant sites. CONCLUSIONS AND HYPOTHESIS: Apparent MTFs are present in peripheral blood of patients with cutaneous melanomas, and they possess the ability to form metastatic lesions when transplanted into mice. We hypothesize that these MTFs arise at the periphery of primary tumors in vivo, that they readily enter the bloodstream and invade distant tissues, secreting cytokines (such as MIF) to prepare "niches" for colonization by metastasis initiating cells.

Durable complete responses off all treatment in patients with metastatic malignant melanoma after sequential immunotherapy followed by a finite course of BRAF inhibitor therapy.

We report 3 cases of durable complete response (CR) in patients with BRAF-mutated metastatic melanoma who were initially treated unsuccessfully with sequential immunotherapies (high dose interleukin 2 followed by ipilimumab with or without concurrent radiation therapy). After progression during or post immunotherapy, these patients were given BRAF inhibitor therapy and developed rapid CRs. Based on the concomitant presence of autoimmune manifestations (including vitiligo and hypophysitis), we postulated that there was a synergistic effect between the prior immune therapy and the BRAF targeting agents. Accordingly, the inhibitors were gradually weaned off beginning at 3 months and were stopped completely at 9-12 months. The three patients remain well and in CR off of all therapy at up to 15 months radiographic follow-up. The institution of the BRAF therapy was associated with development of severe rheumatoid-like arthritis in 2 patients which persisted for months after discontinuation of therapy, suggesting it was not merely a known toxicity of BRAF inhibitors (arthralgias). On immunologic analysis, these patients had high levels of non-T-regulatory, CD4 positive effector phenotype T-cells, which persisted after completion of therapy. Of note, we had previously reported a similar phenomenon in patients with metastatic melanoma who failed high dose interleukin-2 and were then placed on a finite course of temozolomide with rapid complete responses that have remained durable for many years after discontinuation of temozolomide. We postulate that a finite course of cytotoxic or targeted therapy specific for melanoma given after apparent failure of prior immunotherapy can result in complete and durable remissions that may persist long after the specific cytotoxic or targeted agents have been discontinued suggesting the existence of sequence specific synergism between immunotherapy and these agents. Here, we discuss these cases in the context of the literature on synergy between conventional or targeted cytotoxic therapy and immunotherapy in cancer treatment.