Kechter, Jacob

BACKGROUND There is a scarcity of artificial intelligence models trained on frozen pathology. One way to expand the clinical utility of models trained on permanent pathology is by applying them to frozen sections and fine-tune based on weaknesses. OBJECTIVE To qualitatively evaluate a deep learning model trained on permanent pathology to classify squamous cell carcinoma on Mohs surgery frozen sections to learn model shortcomings and inform retraining and fine-tuning. MATERIALS AND METHODS The authors trained a model for classification of tumor on 746 skin biopsy slides and tested it on 15 Mohs surgery frozen sections. The authors estimated performance metrics and compared the regions of interest generated by the model with the original H&E slides. RESULTS The model achieved an AUC-ROC of 0.985 and 0.796 for tumor classification in permanent pathology and in frozen sections, respectively. Regions of interest for frozen sections with scarce tumor areas were inaccurate, focusing on normal tissue for slides classified as false negative, or highlighting structures different from tumor (e.g., inflammation, muscle, and nerves) for slides classified as true positive. CONCLUSION Deep anatomical structures more commonly present in Mohs frozen pathology might represent data out-of-distribution for models trained on permanent pathology, potentially leading to inadequate model outputs.

Background: Hidradenitis suppurativa (HS) is a chronic, recurrent inflammatory condition and is associated with significant psychosocial impacts on patient quality of life. Objective: This study aimed to characterize the utilization of patient-reported outcomes (PROs) in HS clinical trials and their concordance with trial primary endpoints. Methods: A systematic review of clinical trials was performed using the publicly available U.S. National Library of Medicine (ClinicalTrials.gov) in June 2023 utilizing the search terms hidradenitis, hidradenitis suppurativa, and suppurativa hidradenitis. Study title, start year, trial status, intervention, design, location, and primary and secondary outcomes were collected. To assess for concordance of patient and provider-reported outcomes, we identified published placebo-controlled trials that included Dermatology Life Quality Index (DLQI) and/or a numeric rating scale (NRS) for pain, the 2 most utilized PROs. Results: One hundred sixty-four HS clinical trials were identified, of which 115 were interventional studies. A total of 65.2% ( n = 107) of HS trials included at least one PRO. Pain NRS (42.7%, n = 70) and DLQI (42.1%, n = 69) were the most frequently used PRO instruments. The use of PROs in clinical trials increased over time, with 50% of trials between 2020 and 2023 utilizing PROs. Of 11 published HS trials, 82% ( n = 9) trials showed concordance of provider-assessed and PROs in at least one treatment arm. Limitations: Significance and standard deviations of PROs were rarely reported, preventing the calculation of significance and is a limitation of this review. Conclusion: While lesion counts provide single snapshots of disease, PROs can capture perceptions of lesions not actively present. PROs are frequently concordant with both achievement and nonachievement of primary endpoints in clinical trials.

BACKGROUND Cutaneous lichen planus (LP) is a recalcitrant, difficult-to-treat, inflammatory skin disease characterized by pruritic, flat-topped, violaceous papules on the skin. Baricitinib is an oral Janus kinase (JAK) 1/2 inhibitor that interrupts the signaling pathway of IFN-γ, a cytokine implicated in the pathogenesis of LP. METHODS In this phase II trial, 12 patients with cutaneous LP received 2 mg daily baricitinib for 16 weeks, accompanied by in-depth spatial, single-cell, and bulk transcriptomic profiling of pre- and posttreatment samples. RESULTS An early and sustained clinical response was seen, with 83.3% of patients responsive at week 16. Our molecular data identified a unique, oligoclonal IFN-γ, CD8 + , and CXCL13 + cytotoxic T cell population in LP skin and demonstrated a rapid decrease in IFN signature within 2 weeks of treatment, most prominently in the basal layer of the epidermis. CONCLUSION This study demonstrates the efficacy and molecular mechanisms of JAK inhibition in LP. TRIAL REGISTRATION NCT05188521 FUNDING Eli Lilly, Appignani Benefactor Funds, 5P30AR075043, Mayo Clinic Clinical Trials Stimulus Funds.

AbstractBackgroundPrevious literature on cutaneous squamous cell carcinoma (cSCC) suggests that the incidence, rate of metastasis, and tumour severity of cSCC are higher in immunosuppressed patients than in immunocompetent patients. However, current literature lacks an extensive comparison of cSCC clinical characteristics and outcomes in immunosuppressed patients.ObjectivesWe compared cSCC tumour characteristics and disease‐related outcomes to help guide the clinical management of immunosuppressed patients.MethodsWe conducted a retrospective review of histopathologic and clinical data from 935 cSCC cases (19.5% immunosuppressed) from the Mayo Clinic.ResultsImmunosuppression was associated with younger age (69.3 vs. 74.8 years old, p < 0.0001), male gender (78.6% vs. 67.2%, p = 0.003), and higher grade cSCC tumour characterized by moderate or poor differentiation (25.7% vs. 15.8%, p = 0.009; 9.2% vs. 7.2%, p = 0.009, respectively). No significant differences were found in other tumour characteristics, including clinical tumour dimension, Brigham and Women's Hospital tumour staging or cumulative risk of metastasis and recurrence. Immunosuppressed patients had an increased risk of disease‐specific death on univariate analysis (hazard ratio [HR] [95% confidence interval, CI] 2.05 [1.13–3.74], p = 0.0128). Overall survival in the immunosuppressed population was worse (adjusted HR [95% CI] 1.83 [1.42–2.35], p < 0.001) and, notably, solid organ transplant recipients had the lowest overall survival when stratifying immunosuppressed patients by immunosuppression type (HR [95% CI] 1.62 [1.17–2.24], p < 0.0001).ConclusionsIn our study, immunosuppression status was predictive of poor differentiation of tumours and a reduction in overall and cSCC‐specific survival. Current staging systems for cSCC do not include immunosuppression as a risk factor and incorporating immune status may be beneficial for accurate risk stratification.

AbstractBackgroundPrimary cutaneous B‐cell lymphoma (PCBCL) is a group of B‐cell lymphomas of the skin containing primary cutaneous follicle centre lymphoma (PCFCL) and marginal zone B‐cell lymphoma/lymphoproliferative disorder (PCMZL), which are indolent, and diffuse large B‐cell lymphoma, leg type (PCDLBCL‐LT), which is aggressive.ObjectivesTo evaluate treatment outcomes between PCBCL subtypes after treatment with rituximab and to compare the efficacy of intralesional against systemic rituximab in indolent subtypes.MethodsA search for patients diagnosed with PCBCL and treated with rituximab (systemic or intralesional) across all Mayo Clinic sites was performed, yielding 39 patients.ResultsEight patients had PCFCL (six treated intralesionally and two systemically), 11 had PCMZL (four intralesional, eight systemic with one dual‐treated) and 20 had PCDLBCL‐LT (all systemic). The average age at diagnosis was 62.1 years (SD = 15.1), with average follow‐up of 1852.6 days (SD = 1473.2). 69.2% of all patients treated with any form of rituximab experienced a complete response (100% PCFCL, 81.8% PCMZL and 50% PCDLBCL‐LT). When comparing all three subtypes, a significant difference was seen in overall treatment response (p = 0.022), and progressive disease rates (p = 0.015), but not in retreatment with rituximab (p = 0.440), time to retreatment (p = 0.757), recurrence (p = 0.907) or survival (p = 0.093). In the indolent subtypes, no difference in overall treatment response (p = 1.000), progressive disease rates (p = 1.000), recurrence (p = 0.650), rituximab retreatment (p = 0.650) or time to retreatment (p = 0.724) was observed.ConclusionsThis study suggests that rituximab, as systemic therapy and intralesional therapy, is effective in the management of PCBCL, and that intralesional therapy should be considered before more aggressive therapy in indolent disease.