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.

Isolated hyperthermic perfusions for cutaneous melanoma in-transit metastasis of the limb and uveal melanoma metastasis to the liver.

Patients with cutaneous melanoma can develop in-transit metastases (ITM), most often localized to limbs. For patients with uveal melanoma that develop metastatic disease, the overall majority develop isolated liver metastases. For these types of metastases, regional cancer therapies have evolved as effective treatments. Isolated limb perfusion (ILP), isolated limb infusion (ILI), isolated hepatic perfusion (IHP) and percutaneous hepatic perfusion (PHP) achieve a high local concentration of chemotherapy with minimal systemic exposure. This review discusses the mechanism and available literature on locoregional treatment modalities in the era of modern immunotherapy.

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.

Oncolytic intralesional therapy for metastatic melanoma.

In-transit metastasis (ITM) develop in approximately 1 in 10 patients with melanoma and the disease course can vary widely. Surgical resection is the gold-standard treatment; however, ITM are often surgically unresectable due to size, distribution, and/or anatomic involvement. Oncolytic viral therapies are one category of non-surgical treatment options available for ITM. They induce tumor cell lysis and systemic anti-tumor activity through selective infection of tumor cells by naturally occurring or genetically modified factors. While there are numerous oncolytic viral therapies in various stages of development for the treatment of ITM, this discussion focuses on the mechanism and available literature for the two most established herpes virus-based therapies.

A safety review of recently approved and late-stage trial treatments for metastatic melanoma: systemic and regional therapies.

INTRODUCTION: Advanced melanoma accounts for the majority of skin cancer-associated deaths. Over the past 15 years, there has been a dramatic change in the treatment options and prognosis for patients with advanced melanoma secondary to the development of novel systemic immunotherapies (IO) and targeted therapies. In addition to these novel systemic therapies, regional therapies (intralesional and perfusional) also continue to play a major role in the management of these patients. AREAS COVERED: In this article, we review recent updates in the management of advanced melanoma via Medline (PubMed) and Google Scholar, including recently published trials in the metastatic, adjuvant, and neoadjuvant settings. We also review recently published trials for regional therapies and discuss future directions in the management of patients with advanced melanoma. EXPERT OPINION: A significant portion of patients with advanced melanoma will develop recurrent or progressive disease following treatment with IO or targeted therapy. Therefore, identifying not only the appropriate therapeutic agent but also the sequence and duration of treatment is pivotal for these patients.

Active surveillance of patients who have sentinel node positive melanoma: An international, multi-institution evaluation of adoption and early outcomes after the Multicenter Selective Lymphadenectomy Trial II (MSLT-2).

BACKGROUND: For patients with sentinel lymph node (SLN)-positive cutaneous melanoma, the Second Multicenter Selective Lymphadenectomy trial demonstrated equivalent disease-specific survival (DSS) with active surveillance using nodal ultrasound versus completion lymph node dissection (CLND). Adoption and outcomes of active surveillance in clinical practice and in adjuvant therapy recipients are unknown. METHODS: In a retrospective cohort of SLN-positive adults treated at 21 institutions in Australia, Europe, and the United States from June 2017 to November 2019, the authors evaluated the impact of active surveillance and adjuvant therapy on all-site recurrence-free survival (RFS), isolated nodal RFS, distant metastasis-free survival (DMFS), and DSS using Kaplan-Meier curves and Cox proportional hazard models. RESULTS: Among 6347 SLN biopsies, 1154 (18%) were positive and had initial negative distant staging. In total, 965 patients (84%) received active surveillance, 189 (16%) underwent CLND. Four hundred thirty-nine patients received adjuvant therapy (surveillance, 38%; CLND, 39%), with the majority (83%) receiving anti-PD-1 immunotherapy. After a median follow-up of 11 months, 220 patients developed recurrent disease (surveillance, 19%; CLND, 22%), and 24 died of melanoma (surveillance, 2%; CLND, 4%). Sixty-eight patients had an isolated nodal recurrence (surveillance, 6%; CLND, 4%). In patients who received adjuvant treatment without undergoing prior CLND, all isolated nodal recurrences were resectable. On risk-adjusted multivariable analyses, CLND was associated with improved isolated nodal RFS (hazard ratio [HR], 0.36; 95% CI, 0.15-0.88), but not all-site RFS (HR, 0.68; 95% CI, 0.45-1.02). Adjuvant therapy improved all-site RFS (HR, 0.52; 95% CI, 0.47-0.57). DSS and DMFS did not differ by nodal management or adjuvant treatment. CONCLUSIONS: Active surveillance has been adopted for most SLN-positive patients. At initial assessment, real-world outcomes align with randomized trial findings, including in adjuvant therapy recipients. LAY SUMMARY: For patients with melanoma of the skin and microscopic spread to lymph nodes, monitoring with ultrasound is an alternative to surgically removing the remaining lymph nodes. The authors studied adoption and real-world outcomes of ultrasound monitoring in over 1000 patients treated at 21 centers worldwide, finding that most patients now have ultrasounds instead of surgery. Although slightly more patients have cancer return in the lymph nodes with this strategy, typically, it can be removed with delayed surgery. Compared with up-front surgery, ultrasound monitoring results in the same overall risk of melanoma coming back at any location or of dying from melanoma.

Re-biopsy of partially sampled thin melanoma impacts sentinel lymph node sampling as well as surgical margins.

AIM: To assess the impact of re-biopsy on partially sampled melanoma in situ (MIS), atypical melanocytic proliferation (AMP) and thin invasive melanoma. MATERIALS & METHODS: We retrospectively identified cases of re-biopsied partially sampled neoplasms initially diagnosed as melanoma in situ, AMP or thin melanoma (Breslow depth ≤0.75 mm). RESULTS & CONCLUSION: Re-biopsy led to sentinel lymph node biopsy (SLNB) in 18.3% of cases. No patients upstaged from AMP or MIS had a positive SLNB. One out of nine (11.1%) initially diagnosed as a thin melanoma ≤0.75 mm, upstaged with a re-biopsy, had a positive SLNB. After re-biopsy 8.5% underwent an increased surgical margin. Selective re-biopsy of partially sampled melanoma with gross residual disease can increase the accuracy of microstaging and optimize treatment regarding surgical margins and SLNB.

Observational study of talimogene laherparepvec use for melanoma in clinical practice in the United States (COSMUS-1).

AIM: Talimogene laherparepvec (T-VEC) is an intralesional treatment for unresectable cutaneous, subcutaneous and nodal melanoma. COSMUS-1 was conducted to examine how T-VEC is used in US clinical practice. MATERIALS & METHODS: A chart review was conducted at seven centers, with 78 patients screened and 76 eligible. RESULTS: Patients began treatment with T-VEC between October 2015 and December 2016. Median follow-up was 9.4 months. Twenty percent of patients (n = 15) completed T-VEC treatment with no remaining injectable lesions or pathologic complete response. Flu-like symptoms were the most commonly reported adverse events (n = 8; 10.5%), followed by lesion ulceration (n = 4; 5.3%). No herpetic lesions or infections were reported. CONCLUSION: T-VEC was well tolerated and showed clinical utility.

Clinical Correlates of Response to Anti-PD-1-based Therapy in Patients With Metastatic Melanoma.

Anti-PD-1 agents, alone or in combination with ipilimumab, produce durable responses in some melanoma patients. Tumor features that correlate with response are not well defined. We collected clinical data from metastatic melanoma patients treated at 2 centers who received anti-PD-1 (n=303) or anti-PD-1+ipilimumab (n=57). We correlated number of metastases, diameter of largest tumor (tumor bulk), and organ involvement with response rate (RR), progression-free survival (PFS), and overall survival (OS). Patients with diameter of largest tumor ≤2 cm had a 53% RR, whereas those with largest tumor >2 cm had a 38% RR (P=0.009). Those with liver metastases had lower RR (25% vs. 43%; P=0.002). RR to anti-PD-1 was greater in patients with ≤10 metastases compared with those with >10 (39% vs. 27%; P=0.027). In multivariable analyses, size of the largest tumor was independently associated with PFS (P=0.0005), OS (P<0.0001), and RR (P=0.02), whereas AJCC stage, lactate dehydrogenase, liver metastases, ECOG performance status, number of metastases, and prior therapies were not. In patients treated with anti-PD-1+ipilimumab, however, tumor bulk was not associated with outcomes, although number of metastases was associated with PFS (P=0.035) and RR (P=0.009) but not OS. Pathologic analysis did not reveal differences in T-cell infiltration in bulky versus small tumors. Tumor bulk, defined by diameter of largest tumor, was strongly and independently associated with clinical outcomes in anti-PD-1 but not in anti-PD-1+ipilimumab. In conjunction with molecular biomarkers, clinical predictors may help guide selection of immunotherapy agents.

Management of intussusception in patients with melanoma.

BACKGROUND: Increased cross-sectional imaging for surveillance of metastatic melanoma has led to more diagnoses of asymptomatic intussusception. METHODS: We performed a multi-institutional retrospective review of patient records with a history of metastatic melanoma and a diagnosis of intussusception. Patients were divided into three groups: 1) asymptomatic patients without current evidence of melanoma (no evidence of disease [NED]); 2) asymptomatic intussusception and known active metastatic melanoma; 3) symptomatic intussusception and known active metastatic melanoma; the number of patients requiring surgery and intraoperative findings were recorded. RESULTS: We reviewed 73 patients diagnosed with intussusception from 2004 to 2017. Among asymptomatic patients with NED (n = 16), 14 spontaneously resolved and 2 underwent pre-emptive surgery without abnormal intraoperative findings. Of asymptomatic patients with active metastatic disease (n = 32), 25 were initially observed and 7 underwent pre-emptive surgery and 9 of the 25 initially observed patients required surgery for development of symptoms. In this group, all 16 patients undergoing surgery (50% of the group) had intraoperative findings of intussusception and/or metastatic intestinal melanoma.. All symptomatic patients with metastatic melanoma (n = 25) underwent surgery; all had intraoperative findings of intussusception and/or metastatic melanoma except 1 (Meckel's diverticulum). CONCLUSION: Asymptomatic patients with NED do not require surgery and intussusception will likely resolve spontaneously. Asymptomatic patients with known metastatic melanoma may be initially observed, but a low threshold for surgery should be maintained. Symptomatic patients with known metastases should undergo surgery.

Real-World Outcomes of Talimogene Laherparepvec Therapy: A Multi-Institutional Experience.

BACKGROUND: Talimogene laherparepvec (TVEC) is an FDA-approved oncolytic herpes virus used to treat unresectable stage IIIB to IV metastatic melanoma via intralesional injection. This study aims to characterize the efficacy TVEC in patients with unresectable stage IIIB to IV melanoma. METHODS: We performed a multi-institutional, IRB-approved review of all patients who received TVEC at 3 centers from October 2015 to October 2018. Clinicopathologic characteristics, TVEC treatment data, and outcomes were assessed. RESULTS: One hundred and twenty-one patients received TVEC, of which 80 patients had available treatment response data with at least 3-month follow-up. Anatomic sites treated were 19 (24%) head and neck, 9 (11%) upper extremity, 12 (15%) torso, and 40 (50%) lower extremity. Thirty-four (42.5%) patients did not receive therapy before TVEC. Side effects were mild and self-limited, most commonly flu-like symptoms seen in 22 (28%) patients. Median follow-up was 9 months (range 3 to 28 months), with complete local response in 31 (39%) and partial response in 14 (18%) patients. Of complete responders, 29 (37%) had no evidence of disease at last follow-up and received a median of 6 (range 2 to 12) cycles of therapy. CONCLUSIONS: Talimogene laherparepvec is a well-tolerated, durable treatment option for patients with unresectable locoregional melanoma, particularly in stage IIIB/C disease. Additionally, we found that TVEC can be administered safely across anatomic sites that are otherwise not amenable to other local therapies.

Management of Sentinel Lymph Node Metastasis in Merkel Cell Carcinoma: Completion Lymphadenectomy, Radiation, or Both?

BACKGROUND: Approximately 30% of patients with clinically localized Merkel cell carcinoma (MCC) show nodal involvement on sentinel lymph node biopsy (SLNB). Optimal management of SLNB-positive disease has not been defined. This study compared outcomes after completion lymphadenectomy (CLND), radiation, and combined CLND plus radiation after a positive SLNB. METHODS: All patients treated at a single institution for SLNB-positive MCC (1998-2015) were retrospectively evaluated, with examination of patient demographics, clinicopathologic characteristics, outcomes, and regional toxicity. RESULTS: The study identified 71 evaluable patients with SLNB-positive disease. The median age of these patients was 76 years, and 76.1% were men. Of the 71 patients, 11 (15.5%) underwent CLND, 40 (56.3%) received radiation, and 20 (28.2%) underwent CLND plus postoperative radiation. Lymphovascular invasion was significantly more common in the radiation-alone cohort (p = 0.04). For the three cohorts, the median percentages of nodal involvement were respectively 2, 10, and 30% (p = 0.06). After a median follow-up period of 22.3 months, four patients had recurrence in their regional nodal basin (3 radiation-alone patients and 1 CLND + radiation patient). The three cohorts did not differ significantly in the development of distant metastases (p = 0.68) or overall survival (p = 0.72). Six patients experienced surgical-site infections (2 CLND and 4 CLND + radiation patients), and three patients experienced symptomatic lymphedema (1 CLND patient and 2 CLND + radiation patients). CONCLUSIONS: Regional failure was infrequent (≤ 10%) regardless of treatment, and morbidity appeared to be low with all approaches. Given that multiple treatment approaches can be successful in treating micrometastatic MCC, future efforts should be directed at refining criteria for allocating patients to a specific method, or possibly no further nodal basin treatment, in an effort to maximize regional control at the lowest cost and morbidity.

Talimogene Laherparepvec (TVEC) for the Treatment of Advanced Melanoma: A Single-Institution Experience.

BACKGROUND: Talimogene laherparepvec (TVEC) is an oncolytic herpes virus used as intralesional therapy for patients with unresectable stage IIIB through IV melanoma. We reviewed the standard of care treatment of TVEC at a single institution. METHODS: All patients treated with TVEC for advanced melanoma were retrospectively evaluated from 2015 to 2018. Patient demographics, clinicopathologic characteristics, treatment response, and toxicity were reviewed. RESULTS: Twenty-seven patients underwent therapy with TVEC. Median age was 75 years, and 63% of patients were female. Seventeen (63.0%) patients underwent injections on the lower extremity, four (14.8%) on the upper extremity, four (14.8%) on the head and neck, and two (7.4%) on the trunk. Median number of injections was five. Median follow-up was 8.6 months. Of the 27 patients, 23 patients met the criteria for response analysis with at least 8 weeks follow-up. Ten (43.5%) patients experienced a complete response (CR), three (13.1%) experienced a partial response (PR), and five (21.7%) had stable disease (SD) for an overall response rate of 56.5% (CR + PR) and a disease control rate of 78.3% (CR + PR + SD). Adverse events were mostly limited to mild constitutional symptoms within 48 h of injection. Two patients developed cellulitis treated with oral antibiotics, and one patient underwent excision of a lesion for ulceration and bleeding during therapy. DISCUSSION: TVEC is an effective and well-tolerated intralesional therapy for patients with unresectable stage IIIB through IV melanoma. A CR was achieved in almost half of patients treated. Disease control is seen in the vast majority.

Severe thromboembolic phenomenon in the setting of pseudoprogression of melanoma brain metastases in response to combination immunotherapy.

Approximately half of patients with metastatic melanoma develop brain metastasis (MBM) in their disease course. However, patients with MBM were often excluded from early immunotherapy trials, and therefore, the role of immunotherapy in these patients is less clear. We review the case of a patient with widespread metastatic melanoma and symptomatic brain metastases at initial diagnosis. In this case, we have demonstrated that it is reasonable to pursue combination ipilimumab and nivolumab in borderline performance status patients with extensive brain metastases. Additionally, this case teaches us to be vigilant for severe autoimmune toxicities such as severe thrombotic events in the setting of pseudoprogression of brain metastases. We discuss this case in the context of the current melanoma literature.

Resection Margins in Merkel Cell Carcinoma: Is a 1-cm Margin Wide Enough?

BACKGROUND: Guidelines regarding specific resection margins for primary Merkel cell carcinoma (MCC) are not well established. The current National Comprehensive Cancer Network (NCCN) guidelines recommend 1- to 2-cm resection margins. This study aimed to determine the impact of margin width on local recurrence (LR), disease-specific survival (DSS), overall survival (OS), and type of wound closure. METHODS: All patients who underwent resection of primary MCC at a single institution from 2000 to 2015 were reviewed. Patient demographics, clinicopathologic characteristics, treatments, and outcomes were reviewed. RESULTS: A total of 240 patients underwent resection of primary MCC with resection margin width identified in the operative report. The median age was 76 years, and 65.8% of the patients were men. Of the 240 patients, 85 (35.4%) had head and neck primaries, 140 (58.3%) had extremity primaries, and 15 (6.3%) had trunk primaries. In terms of margins, 69 patients (28.8%) had a margin of 1 cm, 36 patients (15%) had a margin of 1.1-1.9 cm, and 135 patients (56.2%) had a margin of 2 cm or more. The median follow-up period was 21 months. The LR rate was 2.9% for a margin of 1 cm, 2.8% for a margin of 1.1-1.9 cm, and 5.2% for a margin of 2 cm or more (p = 0.80). The 5-year OS was 63.6% for a margin of 1 cm, 59.7% for a margin of 1.1-1.9, and 70.7% for a margin of 2 cm or more (p = 0.66). The 5-year DSS was 80.3% for a margin of 1 cm, 66.2% for a margin of 1.1-1.9 cm, and 91.8% for a margin of 2 cm or more (p = 0.28). For wound closure, 43.5, 50, and 65.9% of the patients respectively required a flap or graft with a margin of 1, 1.1-1.9, and 2 cm or more (p = 0.006). CONCLUSIONS: A 1-cm resection margins did not increase the risk of LR. Margin width did not make a significant difference in DSS or OS. Larger resection margins increase the need for a graft or flap closure.

Current standards of surgical management in primary melanoma.

Melanoma accounts for the majority of skin cancer-related deaths, and its incidence continues to rise worldwide. While advanced disease has historically been associated with poor long-term survival, early-stage disease has a favorable prognosis and therefore, early diagnosis is paramount. Resection of primary melanoma requires a balance of maximizing oncological outcome while minimizing morbidity. Wide excision with 1-2 cm margins, depending on depth of the tumor, is the standard of care for surgical treatment of primary, invasive melanoma. Sentinel lymph node biopsy is indicated for patients with clinically node-negative, intermediate-thickness primary melanomas but should also be considered in selected patients with thin and thick primaries. In this article, historical perspectives and key clinical trials regarding the current guidelines for the surgical management of primary melanoma are discussed.

Hepatic Progression-free and Overall Survival After Regional Therapy to the Liver for Metastatic Melanoma.

OBJECTIVES: Regional therapy for metastatic melanoma to the liver represents an alternative to systemic therapy. Hepatic progression-free survival (HPFS), progression-free survival (PFS), and overall survival (OS) were evaluated. MATERIALS AND METHODS: A retrospective review of patients with liver metastases from cutaneous or uveal melanoma treated with yttrium-90 (Y90), chemoembolization (CE), or percutaneous hepatic perfusion (PHP) was conducted. RESULTS: Thirty patients (6 Y90, 10 PHP, 12 CE, 1 PHP then Y90, 1 CE then PHP) were included. Multivariate analysis showed improved HPFS for PHP versus Y90 (P=0.004), PHP versus CE (P=0.02) but not for CE versus Y90. PFS was also significantly different: Y90 (54 d), CE (52 d), PHP (245 d), P=0.03. PHP treatment and lower tumor burden were significant predictors of prolonged PFS on multivariate analysis. Median OS from time of treatment was longest, but not significant, for PHP at 608 days versus Y90 (295 d) and CE (265 d), P=0.24. Only PHP treatment versus Y90 and lower tumor burden had improved OS on multivariate analysis (P=0.03, 0.03, respectively). CONCLUSIONS: HPFS and PFS were significantly prolonged in patients treated with PHP versus CE or Y90. Median OS in PHP patients was over double that seen in Y90 or CE patients but was significant only between PHP and Y90.

Isolated Limb Infusion: A Single-Center Experience with Over 200 Infusions.

BACKGROUND: Isolated limb infusion (ILI) is a minimally invasive technique for delivering regional chemotherapy to an extremity for patients with locally advanced cutaneous malignancies and sarcoma. METHODS: A single-institution, prospectively collected database was analyzed for intention-to-treat with ILI. RESULTS: From 2007 to 2016, 163 patients underwent 205 procedures (201 were successfully completed), and four malignancies were treated: melanoma (72.1% of all ILIs), sarcoma (23.4%), squamous cell carcinoma (SCC; 2.0%) and Merkel cell carcinoma (MCC; 2.5%). A median grade II regional Wieberdink toxicity score was observed, with 88.1% of patients experiencing grade II or less. Median follow-up was 21.8 months, and overall response rate (ORR) was 59.0% for melanoma, 48.9% for sarcoma, 50.0% for SCC, and 60.0% for MCC. A significant difference (p = 0.04) between upper (76.9%) and lower extremity (55.1%) ORR was observed in patients with melanoma. When comparing responders with nonresponders, patients with melanoma had significantly longer in-field progression-free survival (IPFS; 14.1 vs. 3.2 months, p < 0.001), distant metastatic-free survival (DMFS; not reached vs. 25.8 months, p = 0.006), and overall survival (OS; 56.0 vs. 26.7 months, p = 0.0004). Sarcoma responders had a significantly longer IPFS (13.0 vs. 2.7 months, p < 0.0001), but no significant distant metastatic or OS advantage. Over a median follow-up of 19.3 months, sarcoma patients had an overall limb salvage rate of 68.4%. CONCLUSION: ILI is a well-tolerated procedure for patients with locally advanced melanoma, sarcoma, and other cutaneous malignancies. ILI responders had a significantly longer time to IPFS, while melanoma responders also had a DMFS and OS advantage.