Anti-PD1 checkpoint inhibitor therapy in acral melanoma: a multicenter study of 193 Japanese patients.

BACKGROUND: Acral melanoma (AM) is an epidemiologically and molecularly distinct entity that is underrepresented in clinical trials on immunotherapy in melanoma. We aimed to analyze the efficacy of anti-programmed cell death 1 (anti-PD-1) antibodies in advanced AM. PATIENTS AND METHODS: We retrospectively evaluated unresectable stage III or stage IV AM patients treated with an anti-PD-1 antibody in any line at 21 Japanese institutions between 2014 and 2018. The clinicobiologic characteristics, objective response rate (ORR, RECIST), survival estimated using Kaplan-Meier analysis, and toxicity (Common Terminology Criteria for Adverse Events 4.0.) were analyzed to estimate the efficacy of the anti-PD-1 antibodies. RESULTS: In total, 193 patients (nail apparatus, 70; palm and sole, 123) were included in the study. Anti-PD-1 antibody was used as first-line therapy in 143 patients (74.1%). Baseline lactate dehydrogenase (LDH) was within the normal concentration in 102 patients (52.8%). The ORR of all patients was 16.6% (complete response, 3.1%; partial response, 13.5%), and the median overall survival (OS) was 18.1 months. Normal LDH concentrations showed a significantly stronger association with better OS than abnormal concentrations (median OS 24.9 versus 10.7 months; P < 0.001). Although baseline characteristics were similar between the nail apparatus and the palm and sole groups, ORR was significantly lower in the nail apparatus group [6/70 patients (8.6%) versus 26/123 patients (21.1%); P = 0.026]. Moreover, the median OS in this group was significantly poorer (12.8 versus 22.3 months; P = 0.03). CONCLUSIONS: Anti-PD-1 antibodies have limited efficacy in AM patients. Notably, patients with nail apparatus melanoma had poorer response and survival, making nail apparatus melanoma a strong candidate for further research on the efficacy of novel combination therapies with immune checkpoint inhibitors.

The efficacy of eribulin mesylate for patients with cutaneous angiosarcoma previously treated with taxane: a multicentre prospective observational study.

BACKGROUND: Taxanes are the current first-line treatment for advanced cutaneous angiosarcoma (CAS) for patients who are considered difficult to treat with doxorubicin owing to advanced age or comorbidity. However, no effective second-line therapy for such patients has been established. METHODS: We designed a single-arm prospective observational study of eribulin mesylate (ERB) administered at a dose of 1·4 mg m-2 on days 1 and 8 in a 21-day cycle. Patients with advanced CAS who were previously treated with a taxane and were scheduled to begin ERB treatment were enrolled. The primary endpoint was overall survival (OS) and the secondary endpoints were response rate (RR), progression-free survival (PFS) and toxicity assessment. RESULTS: We enrolled a total of 25 patients. The median OS and PFS were 8·6 months and 3·0 months, respectively. The best overall RR was 20% (five of 25). In total, 16 grade 3/4 severe adverse events (SAEs) occurred; however, all patients recovered. Patients who achieved partial response or stable disease as best response had longer OS than those with progressive disease (median OS not reached and 3·3 months, respectively; P < 0·001). Patients who did not experience SAEs showed longer OS than those who did (median OS 18·8 months and 7·5 months, respectively; P < 0·05). Patients with distant metastasis had shorter median OS than those with locoregional disease, but without statistically significant difference. CONCLUSIONS: ERB showed a promising RR and is a potential candidate for second-line treatment for patients with CAS, after treatment with taxanes. However, owing to the occurrence of SAEs in over half of the participants, caution should be exercised regarding ERB use in elderly patients. What is already known about this topic? Taxanes are the current first-line treatment for patients with advanced cutaneous angiosarcoma (CAS) who are considered difficult to treat with doxorubicin owing to advanced age or comorbidity. No effective therapy for taxane-resistant CAS has been established thus far. Eribulin suppresses microtubule polymerization and elicits an antitumour effect similar to that of taxanes. What does this study add? In our single-arm prospective observational study to evaluate the efficacy of eribulin for treating patients with advanced CAS who previously received taxanes, the median overall survival and progression-free survival were 8·6 and 3·0 months, respectively. Response rates at weeks 7, 13 and 25 were 20%, 17% and 14%, respectively. Although 16 grade 3/4 severe adverse events occurred, all patients recovered. Eribulin showed a promising response rate and is a potential candidate for second-line treatment in CAS after taxane treatment. Linked Comment: Smrke and Benson. Br J Dermatol 2020; 183:797-798.

Evaluation of the fat plane of the pancreatic groove using multidetector CT.

AIM: To assess the pancreatic groove fat plane in the normal population and compare this with the fat plane in patients with groove pancreatitis or carcinoma using multidetector computed tomography (CT). MATERIAL AND METHODS: The pancreatic groove fat plane was evaluated retrospectively in 460 normal subjects (normal group), and in 25 patients with groove pancreatitis or carcinoma (pathology group) using 5 mm- and 1 mm-thick slices of unenhanced axial multidetector CT images. Two investigators independently assessed the degree of pancreatic groove fat plane visualisation using a four-point scale (grade 1: visualisation of 0-25%, grade 2: 26-50%, grade 3: 51-75%, grade 4: 76-100%). Pancreatic parenchymal condition, age, sex, body mass index, diabetes mellitus, and dyslipidaemia were also evaluated. RESULTS: The interobserver agreement for the visualisation grades was almost perfect (k-value = 0.95). In the normal group, grade 4 visualisation of the pancreatic groove fat plane was more common in those aged >80 years (78.6%) compared with younger age groups. Pancreatic atrophy and fatty infiltration significantly improved fat plane visualisation. In the pathology group, grade 4 visualisation of the pancreatic groove fat plane was not seen in either groove carcinoma or pancreatitis. A cut-off point of ≤50% visualisation of the pancreatic groove fat plane showed 95% sensitivity and 82% specificity for detecting possible abnormalities in older patients (>60 years). The clinical factors investigated were not significantly related to pancreatic groove fat plane visualisation. CONCLUSION: Pancreatic groove fat plane visualisation could be a good predictor for detecting groove abnormalities.

Three-dimensional evaluation of subclinical extension of extramammary Paget disease: visualization of the histological border and its comparison to the clinical border.

BACKGROUND: In extramammary Paget disease (EMPD), Paget cells are sometimes detected outside the clinical border (subclinical extension). However, the spreading pattern of Paget cells in subclinical extension remains unclear. In addition, the macroscopic appearances of lesions accompanied by subclinical extension are totally unknown. OBJECTIVES: To characterize the spreading pattern of Paget cells as well as the macroscopic appearance of lesions of EMPD with subclinical extension. METHODS: Nineteen patients with primary anogenital EMPD underwent mapping biopsies and excisional surgeries; biopsy samples were then taken at the periphery of well-demarcated lesions. Samples were transparentized and subjected to whole-mount immunostaining with anticytokeratin 7 antibody to label Paget cells. The histological border was evaluated in three dimensions by two-photon microscopy. The shape and location of the histological border were compared with those of the clinical border. RESULTS: In 21 samples taken at the lesion where subclinical extension was not shown by mapping biopsy, the shape and location of the histological border were almost identical to those of the clinical border. However, two samples exhibited small foci of Paget cells outside the clinical border, showing subclinically extended satellite lesions. In the two samples taken at the lesions where subclinical extension was shown by mapping biopsy, a continuous arrangement of Paget cells extending beyond the clinical border was identified. Subclinically extended Paget cells were detected solely outside hypopigmented patches with erythema. CONCLUSIONS: In EMPD, at least two patterns of subclinical extension exist: continuous and satellite lesions. Subclinical extension might exist preferentially outside hypopigmented patches with erythema.

Mast cells and basophils in cutaneous immune responses.

Mast cells and basophils share some functions in common and are generally associated with T helper 2 (Th2) immune responses, but taking basophils as surrogate cells for mast cell research or vice versa for several decades is problematic. Thus far, their in vitro functions have been well studied, but their in vivo functions remained poorly understood. New research tools for their functional analysis in vivo have revealed previously unrecognized roles for mast cells and basophils in several skin disorders. Newly developed mast cell-deficient mice provided evidence that mast cells initiate contact hypersensitivity via activating dendritic cells. In addition, studies using basophil-deficient mice have revealed that basophils were responsible for cutaneous Th2 skewing to haptens and peptide antigens but not to protein antigens. Moreover, human basophils infiltrate different skin lesions and have been implicated in the pathogenesis of skin diseases ranging from atopic dermatitis to autoimmune diseases. In this review, we will discuss the recent advances related to mast cells and basophils in human and murine cutaneous immune responses.