Epidermal autophagy and beclin 1 regulator 1 and loricrin: a paradigm shift in the prognostication and stratification of the American Joint Committee on Cancer stage I melanomas.

BACKGROUND: The updated American Joint Committee on Cancer (AJCC) staging criteria for melanoma remain unable to identify high-risk stage I tumour subsets. OBJECTIVES: To determine the utility of epidermal autophagy and beclin 1 regulator 1 (AMBRA1)/loricrin (AMLo) expression as a prognostic biomarker for AJCC stage I cutaneous melanoma. METHODS: Peritumoral AMBRA1 expression was evaluated in a retrospective discovery cohort of 76 AJCC stage I melanomas. AMLo expression was correlated with clinical outcomes up to 12 years in two independent powered, retrospective validation and qualification cohorts comprising 379 AJCC stage I melanomas. RESULTS: Decreased AMBRA1 expression in the epidermis overlying primary melanomas in a discovery cohort of 76 AJCC stage I tumours was associated with a 7-year disease-free survival (DFS) rate of 81·5% vs. 100% survival with maintained AMBRA1 (P < 0·081). Following an immunohistochemistry protocol for semi-quantitative analysis of AMLo, analysis was undertaken in validation (n = 218) and qualification cohorts (n = 161) of AJCC stage I melanomas. Combined cohort analysis revealed a DFS rate of 98·3% in the AMLo low-risk group (n = 239) vs. 85·4% in the AMLo high-risk cohort (n = 140; P < 0·001). Subcohort multivariate analysis revealed that an AMLo hazard ratio (HR) of 4·04 [95% confidence interval (CI) 1·69-9·66; P = 0·002] is a stronger predictor of DFS than Breslow depth (HR 2·97, 95% CI 0·93-9·56; P = 0·068) in stage IB patients. CONCLUSIONS: Loss of AMLo expression in the epidermis overlying primary AJCC stage I melanomas identifies high-risk tumour subsets independently of Breslow depth. What's already known about this topic? There is an unmet clinical need for biomarkers of early-stage melanoma. Autophagy and beclin 1 regulator 1 (AMBRA1) is a proautophagy regulatory protein with known roles in cell proliferation and differentiation, and is a known tumour suppressor. Loricrin is a marker of epidermal terminal differentiation. What does this study add? AMBRA1 has a functional role in keratinocyte/epidermal proliferation and differentiation. The combined decrease/loss of peritumoral AMBRA1 and loricrin is associated with a significantly increased risk of metastatic spread in American Joint Committee on Cancer (AJCC) stage I tumours vs. melanomas, in which peritumoral AMBRA1 and loricrin are maintained, independently of Breslow depth. What is the translational message? The integration of peritumoral epidermal AMBRA1/loricrin biomarker expression into melanoma care guidelines will facilitate more accurate, personalized risk stratification for patients with AJCC stage I melanomas, thereby facilitating stratification for appropriate follow-up and informing postdiagnostic investigations, including sentinel lymph node biopsy, ultimately resulting in improved disease outcomes and rationalization of healthcare costs.

Harnessing autophagy to overcome mitogen-activated protein kinase kinase inhibitor-induced resistance in metastatic melanoma.

BACKGROUND: Patients with malignant melanoma often relapse after treatment with BRAF and/or mitogen-activated protein kinase kinase (MEK) inhibitors (MEKi) owing to development of drug resistance. OBJECTIVES: To establish the temporal pattern of CD271 regulation during development of resistance by melanoma to trametinib, and determine the association between development of resistance to trametinib and induction of prosurvival autophagy. METHODS: Immunohistochemistry for CD271 and p62 was performed on human naevi and primary malignant melanoma tumours. Western blotting was used to analyse expression of CD271, p62 and LC3 in melanoma subpopulations. Flow cytometry and immunofluorescence microscopy was used to evaluate trametinib-induced cell death and CD271 expression. MTS viability assays and zebrafish xenografts were used to evaluate the effect of CD271 and autophagy modulation on trametinib-resistant melanoma cell survival and invasion, respectively. RESULTS: CD271 and autophagic signalling are increased in stage III primary melanomas vs. benign naevi. In vitro studies demonstrate MEKi of BRAF-mutant melanoma induced cytotoxic autophagy, followed by the emergence of CD271-expressing subpopulations. Trametinib-induced CD271 reduced autophagic flux, leading to activation of prosurvival autophagy and development of MEKi resistance. Treatment of CD271-expressing melanoma subpopulations with RNA interference and small-molecule inhibitors to CD271 reduced the development of MEKi resistance, while clinically applicable autophagy modulatory agents - including Δ9-tetrahydrocannabinol and Vps34 - reduced survival of MEKi-resistant melanoma cells. Combined MEK/autophagy inhibition also reduced the invasive and metastatic potential of MEKi-resistant cells in an in vivo zebrafish xenograft. CONCLUSIONS: These results highlight a novel mechanism of MEKi-induced drug resistance and suggest that targeting autophagy may be a translatable approach to resensitize drug-resistant melanoma cells to the cytotoxic effects of MEKi.

Do perioperative antibiotics reduce the risk of surgical-site infections following excision of ulcerated skin cancers? A Critically Appraised Topic.

AIM: To review the efficacy of perioperative antibiotics in reducing the risk of surgical-site infections (SSIs) following excision of ulcerated skin cancers. SETTING AND DESIGN: Study selection, data extraction and analysis were carried out independently by four authors. Only randomized controlled trials (RCTs) reported in the English language were included. INCLUDED STUDIES: RCTs in the English language in which patients received perioperative topical, intralesional or oral antibiotics for dermatological surgery, including Mohs micrographic surgery in general practice, dermatology or plastic surgery departments, were included. OUTCOME: The proportion of participants developing SSI following excision of skin lesions. RESULTS: Thirteen RCTs were identified from our literature search of PubMed and Embase, which evaluated SSI following use of topical (n = 5), oral (n = 3), intramuscular (n = 2), intravenous (n = 1) and intralesional antibiotics (n = 2) in dermatological surgery. Two RCTs specifically investigated SSIs in ulcerated skin cancer excisions; one RCT investigated the SSI rate following surgical treatment specifically for ulcerated skin cancers in individuals randomized to topical antibiotics vs. oral cephalexin; and one RCT compared intravenous cefazolin with no antibiotic, demonstrating significant reduction in SSI rates for ulcerated tumours (P = 0·04). CONCLUSIONS: The heterogeneity of the RCTs included in this study makes it difficult to make a direct comparison of the outcomes measured. High-quality evidence demonstrating a beneficial effect of the use of perioperative antibiotics to prevent SSI following excision of ulcerated skin cancers is lacking. In the absence of an evidence base, we propose that a well-designed multicentre RCT could evaluate the effect of perioperative antibiotics following excision of ulcerated tumours, and potentially reduce inappropriate antibiotic prescription.

Cutaneous manifestations of phosphate solution extravasation.

Extravasation injuries are common in patients receiving multiple intravenous infusions. Although such injuries are closely associated with the infusion of cytotoxic chemotherapy, they have also been been associated with extravasation of noncytotoxic drugs. Extravasation injuries can lead to skin ulceration and nerve and tendon damage, and therefore to permanent disability. We report three cases of phosphate solution extravasation leading to unusual cutaneous manifestations.

Legionella feeleii: an unusual organism associated with cutaneous infection in an immunocompromised patient.

We report a 23-year-old immunocompromised woman who, following cardiac transplantation, presented with an unusual cutaneous eruption. She developed a widespread pustular rash, systemic symptoms and a high temperature with raised inflammatory markers. The diagnosis was reached when a skin biopsy was cultured onto Legionella agar (buffered charcoal yeast extract) and Legionella feeleii was isolated. The patient was treated with 6 weeks of moxifloxacin and her cutaneous lesions gradually resolved. Cutaneous Legionella infections are uncommon and usually affect immunocompromised patients.