Does preoperative imaging for scalp non-melanocytic skin cancer accurately predict invasion of the cranial vault? A systematic review and meta-analysis.

PURPOSE: This study aimed to determine the diagnostic accuracy of CT and MRI in the preoperative detection of bone involvement for non-melanoma skin cancers (NMSCs) located on the scalp. This study further aimed to evaluate the predictive value of these imaging modalities in determining the need for craniectomy and to identify gaps in the existing literature. METHODS: Electronic searches of the MEDLINE, Embase, Cochrane and Google Scholar databases were performed for English language studies of any type. Studies reporting detection or exclusion of histopathologically confirmed bone involvement through preoperative imaging were identified according to PRISMA guidelines. Studies reporting dural involvement, non-scalp tumours, and lacking tumour type(s) or outcome data were excluded. Outcomes were preoperative imaging result and histopathologically confirmed bone invasion. Meta-analysis was performed and sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated (excluding case report and MRI data due to insufficient quality and quantity respectively). RESULTS: Four studies with a total of 69 patients were included in the final review, of which two studies totalling 66 patients were included in the meta-analysis. Preoperative CT had a sensitivity of 38%, specificity of 98%, PPV of 90% and NPV of 73%. CONCLUSIONS: The available data suggests that a preoperative CT finding of calvarial involvement by a scalp NMSC is likely to be real, but the absence of such a finding is unreliable. Current evidence suggests that preoperative imaging cannot exclude the necessity for craniectomy and future research is needed, particularly on the role of MRI.

Has the advent of modern adjuvant systemic therapy for melanoma rendered sentinel node biopsy unnecessary?

The prognostic value of sentinel node biopsy (SNB) is well established and SNB was therefore adopted as a requirement for pathological staging of melanomas>1 mm thick in the American Joint Committee on Cancer (AJCC) 8th edition. Consequently, a negative SNB status became an eligibility criterion for clinical trials of adjuvant systemic therapy in resected stage IIB/C melanoma. However, since the Keynote 716 trial demonstrated an improvement in relapse-free survival (RFS) in patients with Stage IIB/C melanoma, all of whom had SNB staging, some have argued that SNB is no longer required for patients with T3 and T4 primary melanomas. The rationale for omitting SNB is that these patients will be able to access adjuvant immunotherapy regardless of SNB status, avoiding the costs and potential complications of SNB. However, this argument overlooks the prognostic value of knowing a patient's nodal status and the therapeutic benefit of SNB in regional disease control. Based on extrapolation of data from multiple sources, we demonstrate that the risk of regional node-field relapse with SNB and immunotherapy for T3b and T4 melanomas is around 7-9% but is 20-27% without SNB. Similarly, the node-field recurrence rate with SNB alone is around 14% compared to around 40% with no SNB or immunotherapy. Consequently, in the absence of prospective data, we propose that the optimal management of the regional node-field for high-risk T3b and T4 primary melanomas is likely to be achieved by combining SNB and adjuvant immunotherapy for those patients who are suitable, rather than either treatment alone.

Immunotherapy in advanced cutaneous squamous cell carcinoma: Sydney west cancer network experience.

BACKGROUND: Cutaneous squamous cell carcinoma (CSCC) is the second most common malignancy in the Caucasian population. A minority of cases are inoperable at presentation, recur or develop metastatic disease with a historical 5-year overall survival of ~10%. Treatment options in this setting are generally palliative. Immunotherapy has emerged as a new paradigm in managing these patients. METHODS: Patients presenting to Sydney West Cancer Network with locally advanced or metastatic CSCC treated with the anti-PD1 agent cemiplimab were identified. Response to treatment was objectively assessed based on RECIST1.1 or PERCIST criteria. Primary end point was objective response rate (ORR). Secondary end points included progression-free survival (PFS), overall survival (OS), therapy toxicity, and predictors of treatment response. RESULTS: A total of 19 patients were identified with a median age of 76 (range 56-94) and 4 immunosuppressed. The longest follow up duration was 28 months. ORR, complete response (CR), and partial response (PR) were 68% (13/19), 53% (10/19), and 16% (3/19), respectively. Median PFS was 12 months (95% CI 9-14) whilst median OS was not reached by end of study. Responders (CR or PR) had significantly superior OS compared to those with no response (P < 0.01). A primary site of head and neck cancer was significantly associated with ORR (P = 0.04). A single patient experienced Grade 3 toxicity with the rest being Grades 0-1. CONCLUSION: This study confirms the clinical efficacy of cemiplimab in patients with advanced CSCC with many experiencing a durable response and an acceptable adverse effect profile.

Merkel cell carcinoma in situ: A systematic review of prognosis and management.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare primary cutaneous neuroendocrine tumour. While dermally invasive MCC is known to have a five-year survival of only 30-40%, the prognosis and management of MCC in situ (MCCis) is not widely reported. OBJECTIVE: We present a systematic review to elucidate the prognosis and management of MCCis. METHODS: We performed a systematic review, searching three databases to 01 June 2021. Case reports, cohort studies, clinical trials and literature reviews were considered for inclusion. RESULTS: We identified 26 cases of MCCis published in the literature with a median age of 74 years and involving 19 males and 7 females. Most cases were on the face and neck (n = 17), followed by upper limb (n = 8) and lower limb (n = 1). Sentinel lymph node biopsy was performed in three patients, and all were negative. One subject underwent adjuvant radiotherapy. No MCCis-associated deaths were reported. CONCLUSION: This review suggests that MCCis has an excellent prognosis with minimal, if any, risk of mortality and a very low risk of dermal invasion and recurrence when treated with wide local excision alone. Sentinel lymph node biopsy is unlikely to be useful for MCCis.

BRAF mutation testing for patients diagnosed with stage III or stage IV melanoma: practical guidance for the Australian setting.

Targeted therapy (BRAF inhibitor plus MEK inhibitor) is now among the possible treatment options for patients with BRAF mutation-positive stage III or stage IV melanoma. This makes prompt BRAF mutation testing an important step in the management of patients diagnosed with stage III or IV melanoma; one that can help better ensure that the optimal choice of systemic treatment is initiated with minimal delay. This article offers guidance about when and how BRAF mutation testing should be conducted when patients are diagnosed with melanoma in Australia. Notably, it recommends that pathologists reflexively order BRAF mutation testing whenever a patient is found to have American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) stage III or IV melanoma (i.e., any metastatic spread beyond the primary tumour) and that patient's BRAF mutation status is hitherto unknown, even if BRAF mutation testing has not been specifically requested by the treating clinician (in Australia, Medicare-subsidised BRAFV600 mutation testing does not need to be requested by the treating clinician). When performed in centres with appropriate expertise and experience, immunohistochemistry (IHC) using the anti-BRAF V600E monoclonal antibody (VE1) can be a highly sensitive and specific means of detecting BRAFV600E mutations, and may be used as a rapid and relatively inexpensive initial screening test. However, VE1 immunostaining can be technically challenging and difficult to interpret, particularly in heavily pigmented tumours; melanomas with weak, moderate or focal BRAFV600E immunostaining should be regarded as equivocal. It must also be remembered that other activating BRAFV600 mutations (including BRAFV600K), which account for ∼10-20% of BRAFV600 mutations, are not detected with currently available IHC antibodies. For these reasons, if available and practicable, we recommend that DNA-based BRAF mutation testing always be performed, regardless of whether IHC-based testing is also conducted. Advice about tissue/specimen selection for BRAF mutation testing of patients diagnosed with stage III or IV melanoma is also offered in this article; and potential pitfalls when interpreting BRAF mutation tests are highlighted.

Survival Outcomes of Salvage Metastasectomy After Failure of Modern-Era Systemic Therapy for Melanoma.

BACKGROUND: Metastasectomy for selected patients with melanoma was associated with improved survival in the era before effective systemic therapy. Emerging evidence shows that these benefits persist even in this era of BRAF-targeted therapy and immune checkpoint inhibitor immunotherapy. This study aimed to evaluate the outcomes of salvage metastasectomy after failure of systemic therapy. METHODS: Stage 3 or 4 melanoma patients with extracranial disease progression after at least 4 weeks of systemic treatment between 2009 and 2020 were identified and categorized as resected to no evidence of disease (NED), non-progressive residual disease (NPRD), or progressive residual disease (PRD). Systemic therapy was stratified into BRAF-targeted therapy, immune checkpoint inhibitor immunotherapy, or both. The end points of overall survival (OS), progression-free survival (PFS), and locoregional disease control (LRC) were assessed using Kaplan-Meier curves. Uni- and multivariable Cox regression procedures were used to examine factors associated with OS, PFS and LRC. RESULTS: The study enrolled 190 patients. Among all the patients, the 5-year OS from metastatectomy was 52%, the 3-year PFS was 21%, and the 5-year LRC was 61%. After resection to NED, NPRD, and PRD, the 5-year OS values were 69%, 62% and 8%, respectively. Fewer lines of preoperative therapy, use of preoperative immunotherapy, and resection to NED were predictors of improved OS. After resection to NED, NPRD, and PRD, the 3-year PFS values were 23%, 24% and 10%, and the 5-year LRC values were 61%, 72% and 34%, respectively. CONCLUSIONS: Salvage metastasectomy was associated with durable survival and disease control, particularly after resection to NED, preoperative immunotherapy, and fewer lines of preoperative systemic therapy.

Immunotherapy in advanced Merkel cell carcinoma: Sydney west cancer network experience.

INTRODUCTION: Merkel cell carcinoma (MCC) is a highly aggressive skin cancer with no survival benefit demonstrated using palliative cytotoxic chemotherapy in the setting of metastatic MCC. Recently, immune checkpoint inhibitors (anti-PD-L1/PD1) have been approved in this setting after durable clinical response was demonstrated in several clinical trials. In this series, we present a multicentre real-world experience in using anti-PD-L1/PD1 in advanced MCC. METHODS: A retrospective review was performed of all patients with metastatic MCC who were treated with at least one dose of anti-PD-L1/PD1 presenting to Sydney West Cancer Network (Westmead, Nepean and Blacktown hospitals) was performed between 2016 and 2020. Treatment response was assessed based on morphologic and/or metabolic changes of the disease on FDG-PET/CT scans. Primary end point investigated was objective response rate. Secondary outcomes included therapy toxicity, disease control and overall survival. RESULTS: Thirteen patients received anti-PD-L1/PD1 with a median age of 82 (range 62-89). Two patients had undergone prior palliative chemotherapy. The median follow-up time was 17 months (range 2-34). The overall, complete and partial response rates were 77% (10), 54% (7) and 23% (3), respectively. Treatment-related grade 1 or 2 toxicity was experienced by 69% with only 2 cases of greater severity. The median progression-free survival and overall survival were 18 months (95% CI 10-26 months) and 33 months (95% CI range 7.6-58.4 months), respectively. CONCLUSIONS: Consistent with clinical trial results, anti-PD-L1/PD1 therapy in this small series demonstrated efficacy and safety in patients with metastatic MCC.

Outcomes of patients with metastatic cutaneous squamous cell carcinoma to the axilla: a multicentre cohort study.

BACKGROUND: Metastatic cutaneous squamous cell carcinoma to the axilla is uncommon, with limited data to guide management. We sought to assess the outcomes of patients with this condition after surgery and radiotherapy. METHODS: A retrospective cohort study of patients treated at two Australian hospitals from 1994 through 2016 was performed. RESULTS: A total of 74 patients were identified, including 48 treated curatively with surgery-plus-radiotherapy and 15 with surgery alone. Compared with patients treated with surgery alone, a higher proportion of patients treated with surgery-plus-radiotherapy had lymph nodes larger than 6 cm (53% versus 8%, P = 0.012) and multiple adverse histopathological features (75% versus 47%, P = 0.04). The groups had similar 5-year disease-free survival (45% versus 46%) and overall survival (51% versus 48%). Presence of multiple positive lymph nodes was associated with reduced disease-free survival (hazard ratio 4.57, P = 0.01) and overall survival (hazard ratio 3.53, P = 0.02). Regional recurrence was higher in patients treated with surgery alone (38% versus 22%, P = 0.22) and patients with lymph nodes larger than 6 cm (34% versus 10%, P = 0.03). All recurrences occurred within 2 years following treatment. CONCLUSION: Combined-modality therapy for metastatic cutaneous squamous cell carcinoma to the axilla is recommended for high-risk patients, although outcomes remain modest. The key period for recurrence is within 2 years following treatment.

Design and Testing of a Custom Melanoma Next Generation Sequencing Panel for Analysis of Circulating Tumor DNA.

Detection of melanoma-associated mutations using circulating tumor DNA (ctDNA) from plasma is a potential alternative to using genomic DNA from invasive tissue biopsies. In this study, we developed a custom melanoma next-generation sequencing (NGS) panel which includes 123 amplicons in 30 genes covering driver and targetable mutations and alterations associated with treatment resistance. Analysis of a cohort of 74 stage III and IV treatment-naïve melanoma patients revealed that sensitivity of ctDNA detection was influenced by the amount of circulating-free DNA (cfDNA) input and stage of melanoma. At the recommended cfDNA input quantity of 20 ng (available in 28/74 patients), at least one cancer-associated mutation was detected in the ctDNA of 84% of stage IV patients and 47% of stage III patients with a limit of detection for mutant allele frequency (MAF) of 0.2%. This custom melanoma panel showed significant correlation with droplet digital PCR (ddPCR) and provided a more comprehensive melanoma mutation profile. Our custom panel could be further optimized by replacing amplicons spanning the TERT promoter, which did not perform well due to the high GC content. To increase the detection rate to 90% of stage IV melanoma and decrease the sensitivity to 0.1% MAF, we recommend increasing the volume of plasma to 8 mL to achieve minimal recommended cfDNA input and the refinement of poorly performing amplicons. Our panel can also be expanded to include new targetable and treatment resistance mutations to improve the tracking of treatment response and resistance in melanoma patients treated with systemic drug therapies.