Machine learning algorithm to predict response to immunotherapy in real-life settings for patients with advanced melanoma.

BACKGROUND: Melanoma is one of the most fatal forms of skin cancer. Defining relevant biomarkers to predict treatment outcome based on immune checkpoint inhibitors (ICIs) is needed in order to increase overall survival of metastatic melanoma patients (MM). OBJECTIVES: This study compared different machine learning models in terms of performance to identify biomarkers from clinical diagnosis and follow-up of MM patients, to predict treatment response to ICIs under real-life conditions. MATERIALS & METHODS: Clinical data from melanoma patients with an AJCC status of III C/D or IV, having received ICIs, were extracted from the RIC-MEL database for this pilot study. Light Gradient Boosting Machine, linear regression, Random Forest (RF), Support Vector Machine and Extreme Gradient Boosting were compared in terms of performance. The SHAP (SHapley Additive exPlanations) method was used to assess the link between the different clinical features investigated and the prediction of response to ICIs. RESULTS: RF showed the highest scores for accuracy (0.63) and sensitivity (0.64) and high scores for precision (0.61) and specificity (0.63). AJCC stage (0.076) showed the highest SHAP mean value, thus being the most suitable feature to predict response to treatment. The number of metastatic sites per year (0.049), number of months since first treatment initiation and the Breslow index (both 0.032) were less predictive, but still showed relatively high predictive power. CONCLUSION: This machine learning approach confirms that a certain number of biomarkers may enable prediction of treatment success with ICIs.

Prepubertal acne: A retrospective study.

BACKGROUND: Acne vulgaris is a common skin disorder, but studies on the epidemiologic features of prepubertal acne are limited. OBJECTIVES: The aim of this study was to determine the prevalence and severity of prepubertal acne and to identify factors influencing acne severity and poor response to treatment. METHODS: A retrospective study was conducted on 683 patients with acne from our database who visited the dermatology department of Nantes University hospital between October 2014 and May 2018. Patients of prepubertal acne (7-12 years) were included in this study. RESULTS: Of the 683 patients with acne, 24 (3.5%) had prepubertal acne. Prepubertal acne was more common in female patients (75%). Acne severity assessment showed that severe acne (Groupe Expert Acné global acne severity scale 4) was the most common form (33%), and mild and moderate forms (Global Evaluation Acne Group, global acne severity scales 2 and 3) accounted for 25% each. There was a high predominance of phylotype IA1 of Cutibacterium acnes (belonging to CC18 subgroup). The analysis of patients' lifestyle and acne features identified three factors associated with an increased risk of poor response or resistance to acne treatment. Initially severe acne grading (grade 4) was the most strongly associated parameter (p < .028), followed by regular milk consumption and taking other medications in addition to acne treatment (p < .049 for each). CONCLUSION: This study reported on prepubertal acne features and identified three factors associated with a high risk of treatment failure or relapse. Adequate and prompt treatment is needed in this subgroup of patients to minimize disease burden and prevent subsequent disease worsening.

Circulating Tumour DNA Is an Independent Prognostic Biomarker for Survival in Metastatic BRAF or NRAS-Mutated Melanoma Patients.

Circulating tumour DNA (ctDNA) can be used to identify gene alterations. The purpose of this study was to determine whether the detection of ctDNA, based on the identification of BRAF and NRAS mutations before systemic treatment initiation, was associated with the prognosis of metastatic melanoma. In total, 68 BRAF or NRAS-mutated stage IV or unresectable stage III metastatic cutaneous melanoma patients were included and tested for the presence of BRAF and NRAS mutations in circulating DNA before treatment initiation, using the Cobas BRAF/NRAS Mutation Test (Roche). The expected mutation was detected in the plasma of 34/68 patients (50% sensitivity). ctDNA detection was associated with AJCC stage, along with the number and nature of metastases. ctDNA was less frequently detected in NRAS-mutated than in BRAF-mutated melanoma (36% and 66%, respectively). At initiation of first-line treatment, ctDNA detection was associated with poor prognosis in Progression Free Survival (PFS) and Overall Survival (OS) in univariate analysis (log-rank: p = 0.002 and p < 0.0001, respectively). In multivariate analysis, ctDNA detection was an independent factor of poor prognosis in OS, after adjustment for AJCC stage, number and nature of metastases and gender (HR = 4.384; 95% CI: (1.308; 14.699); p = 0.017).

Foetal skin cells in wound healing: a promising tool for clinical application.

The skin is the first protective barrier of our body. Wound healing is therefore an essential mechanism. However, this phenomenon can be impaired when wounds are too large or chronic, for example, in diabetes. Interestingly, adult skin heals with scars, whereas foetuses present scarless regeneration. The objective of this review is to highlight the difference in healing pathways between foetal and adult skin and to present the recent therapeutic strategies envisaged using foetal properties in the clinic. The main features that distinguish foetal wound healing from adult wound healing are less tissue inflammation, faster reepithelialisation, and less contraction of the neodermis, allowing foetal tissues to regenerate. Recently, new therapies in regenerative medicine have been introduced using these foetal properties. For the first time, our team has developed CICAFAST, an innovative dressing composed of foetal keratinocytes and fibroblasts, which has been tested on a skin graft donor site in a clinical Phase 1/2 trial.

CICAFAST: comparison of a biological dressing composed of fetal fibroblasts and keratinocytes on a split-thickness skin graft donor site versus a traditional dressing: a randomized controlled trial.

BACKGROUND: Wound repair is one of the most complex biological processes of human life. Allogeneic cell-based engineered skin substitutes provide off-the-shelf temporary wound coverage and act as biologically active dressings, releasing growth factors, cytokines and extracellular matrix components essential for proper wound healing. However, they are susceptible to immune rejection and this is their major weakness. Thanks to their low immunogenicity and high effectiveness in regeneration, fetal skin cells represent an attractive alternative to the commonly used autologous and allogeneic skin grafts. METHODS/DESIGN: We developed a new dressing comprising a collagen matrix seeded with a specific ratio of active fetal fibroblasts and keratinocytes. These produce a variety of healing growth factors and cytokines which will increase the speed of wound healing and induce an immunotolerant state, with a slight inflammatory reaction and a reduction in pain. The objective of this study is to demonstrate that the use of this biological dressing for wound healing at the split-thickness skin graft (STSG) donor site, reduces the time to healing, decreases other co-morbidities, such as pain, and improves the appearance of the scar. This investigation will be conducted as part of a randomized study comparing our new biological dressing with a conventional treatment in a single patient, thus avoiding the factors that may influence the healing of a graft donor site. DISCUSSION: This clinical trial should enable the development of a new strategy for STSG donor-wound healing based on a regenerative dressing. The pain experienced in the first few days of STSG healing is well known due to the exposure of sensory nerve endings. Reducing this pain will also reduce analgesic drug intake and the duration of sick leave. Our biological dressing will meet the essential need of surgeons to "re-crop" from existing donor sites, e.g., for thermal-burn patients. By accelerating healing, improving the appearance of the scar and reducing pain, we hope to improve the conditions of treatment for skin grafts. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT03334656 . Registered on 7 November 2017.

5-fluorouracil chemowraps for the treatment of multiple actinic keratoses.

Few satisfactory treatment options are available for widespread areas affected by multiple actinic keratoses (AKs). Our primary objective was to assess the response rate to weekly 5-fluorouracil (5-FU) chemowraps on widespread AK lesions, and secondarily to assess tolerability, the percentage of patients with recurrence and time to recurrence, the response rate for patients with associated Bowen's disease (BD), and the percentage of squamous cell carcinomas (SCCs) identified after treatment. We conducted an open study which included all the patients who had been treated with weekly 5-FU chemowraps in our department over the course of five years for areas of widespread AKs. The response rate for AKs was 60%, with 20% complete responses among 25 patients after an average of 9.6 sessions (1 to 64). The treatment had to be discontinued because of toxicity in four patients; one case of contact dermatitis, one case of erosive pustular dermatosis, and two cases of Grade 2 irritations. Invasive SCCs were identified in five patients after treatment cessation. The median recurrence-free survival was five months. A 64% response rate was achieved for associated BD. The weekly application of 5-FU under occlusion seems to be an interesting, well-tolerated therapeutic option for the treatment of widespread AKs.

Evaluation of the colorectal cancer risk conferred by rare UNC5C alleles.

AIM: To evaluate the risk associated with variants of the UNC5C gene recently suspected to predispose to familial colorectal cancer (CRC). METHODS: We screened patients with familial CRC forms as well as patients with sporadic CRCs. In a first time, we analyzed exon 11 of the UNC5C gene in 120 unrelated patients with suspected hereditary CRC, 58 patients with suspected Lynch-associated cancer or polyposis, and 132 index cases of Lynch syndrome families with a characterized mutation in a DNA mismatch repair (MMR). Next, 1023 patients with sporadic CRC and 1121 healthy individuals were screened for the variants identified in patients with familial cancer. RESULTS: Of 120 patients with familial CRC of unknown etiology, one carried the previously reported mis-sense mutation p.Arg603Cys (R603C) and another exhibited the unreported variant of unknown significance p.Thr617Ile (T617I). The p.Ala628Lys (A628K) mutation previously described as the main UNC5C risk variant for familial CRC was not detected in any cases of familial CRC of unknown etiology, but was present in a patient with familial gastric cancer and in two Lynch syndrome patients in co-occurrence with MMR mutations. A statistically non-significant increase in cancer risk was identified in familial CRC and/or other Lynch-associated cancers (1/178 patients vs 2/1121 healthy controls, OR = 3.2, 95%CI: 0.29-35.05, P = 0.348) and in sporadic CRCs (4/1023 patients vs 2/1121 healthy controls, OR = 2.2, 95%CI: 0.40-12.02, P = 0.364). CONCLUSION: We confirm that UNC5C mutations are very rare in familial and sporadic CRCs, but further investigations are needed to justify routine UNC5C testing for diagnostic purposes.