Assessing the Efficacy of Imiquimod Use in Patients With Persistent Locally Advanced Melanoma In Situ

BACKGROUND: The standard of care when treating melanoma in situ (MMIS) is an excision with at least 5 mm surgical margins.1 Some studies have suggested up to 9 mm margins to maximize local recurrence-free survival.2 This retrospective review aims to assess the efficacy of imiquimod as a topical treatment for persistently positive MMIS at the margins of prior excisions or where surgery is not an option. METHODS: Retrospective study conducted at Moffitt Cancer Center between 2019 and 2021 with patients aged > 18 years with MMIS at the margins of excision of an invasive melanoma or MMIS. Included patients were not ideal candidates for primary or additional surgical resection due to non-feasibility of surgery because of comorbidity or cosmetically sensitive location and/or the need for repeated skin grafting, or due to patient's refusal. Patients received imiquimod on protocol for 16 weeks and were monitored for treatment response and side effects. Following completion of the treatment, scouting biopsies were performed to assess histological response, and dermoscopy was used to determine the clinical disease status. RESULTS: Ten patients completed 16 weeks of imiquimod. Seven (75%) had a median of 2 surgical resections, and 3 refused surgery despite discussion that surgery was standard of care. Seven were deemed free of disease on post-imiquimod treatment scouting biopsies, while 2 were found to be clinically free of disease following confocal microscopy, indicating a tumor clearance rate of 90% with imiquimod treatment. One patient was found to have persistent residual disease following 2 rounds of imiquimod and was taken for an additional surgical excision after which they were deemed free of disease. Median follow-up duration from the onset of imiquimod therapy to the last clinic visit was 18 months, without any recurrences to date. CONCLUSION: Imiquimod appears to demonstrate an encouraging tumor clearance among patients with persistent MMIS after surgery where further surgical resection may not be feasible. Although long-term durability has not been demonstrated in this study, a 90% tumor clearance rate is promising. J Drugs Dermatol. 2023;22(5): doi:10.36849/JDD.6987.

Genomic and Single-Cell Landscape Reveals Novel Drivers and Therapeutic Vulnerabilities of Transformed Cutaneous T-cell Lymphoma.

ABSTRACT: Cutaneous T-cell lymphoma (CTCL) is a rare cancer of skin-homing T cells. A subgroup of patients develops large cell transformation with rapid progression to an aggressive lymphoma. Here, we investigated the transformed CTCL (tCTCL) tumor ecosystem using integrative multiomics spanning whole-exome sequencing (WES), single-cell RNA sequencing, and immune profiling in a unique cohort of 56 patients. WES of 70 skin biopsies showed high tumor mutation burden, UV signatures that are prognostic for survival, exome-based driver events, and most recurrently mutated pathways in tCTCL. Single-cell profiling of 16 tCTCL skin biopsies identified a core oncogenic program with metabolic reprogramming toward oxidative phosphorylation (OXPHOS), cellular plasticity, upregulation of MYC and E2F activities, and downregulation of MHC I suggestive of immune escape. Pharmacologic perturbation using OXPHOS and MYC inhibitors demonstrated potent antitumor activities, whereas immune profiling provided in situ evidence of intercellular communications between malignant T cells expressing macrophage migration inhibitory factor and macrophages and B cells expressing CD74. SIGNIFICANCE: Our study contributes a key resource to the community with the largest collection of tCTCL biopsies that are difficult to obtain. The multiomics data herein provide the first comprehensive compendium of genomic alterations in tCTCL and identify potential prognostic signatures and novel therapeutic targets for an incurable T-cell lymphoma. This article is highlighted in the In This Issue feature, p. 1171.

Cutaneous Human Papillomavirus Infection and Development of Subsequent Squamous Cell Carcinoma of the Skin.

The role of cutaneous human papillomavirus (HPV) infection in the development of subsequent cutaneous squamous cell carcinoma (SCC) is unknown. Pathologically confirmed cases of SCC (n = 150) enrolled in a previously conducted case-control study were included in a retrospective cohort study to examine the association of cutaneous HPV at the time of SCC diagnosis with the risk of subsequent SCC development. Data on HPV seropositivity, HPV DNA in eyebrow hairs (EB) and SCC tumors were available from the parent study. Incidence of subsequent SCC was estimated using person-years of follow up. Cox Proportional Hazards ratios were estimated to evaluate the associations of both, HPV seropositivity and HPV DNA positivity with subsequent SCC. The five year cumulative incidence of subsequent SCC was 72%. Seropositivity to cutaneous HPV was not associated with the risk of subsequent SCC (HR = 0.83, 95% CI = 0.41-1.67). Any beta HPV infection in EB was associated with reduced risk (HR = 0.30, 95% CI = 0.11-0.78) of subsequent SCC among cases who were positive for beta HPV DNA in tumor tissue. Infection with beta HPV type 2 (HR = 0.32, 95% CI = 0.12-0.86) in EB was associated with reduced risk of subsequent SCC among HPV DNA positive SCCs. In conclusion, beta HPV infection was inversely associated with the risk of subsequent SCC.