Clinicopathological characteristics of malignant melanomas of the skin and gastrointestinal tract

Metastatic Gastric Mucosal Melanoma: A Rare Case Presenting With Diffuse Gastric Polyposis

We report a 66-year-old Chinese lady who presented with a three-month history of postprandial vomiting, early satiety, anorexia and weight loss, and significant physical findings of hepatomegaly and ascites. Gastroscopy revealed gastric polyposis with both hyperpigmented and unpigmented lesions over the gastric fundus, body, and proximal antrum, biopsies of which yielded malignant melanoma histologically. Cross-sectional imaging with CT also demonstrated extensive hepatic and bony metastases. No cutaneous or ocular primary was detected. She was treated with a combination of ipilimumab and nivolumab but developed interval progression of hepatic metastases after two cycles of immunotherapy. The patient eventually succumbed two months after diagnosis.

Surgical Outcomes of Vaginal or Cervical Melanoma

Objective: To evaluate the effectiveness of radical resection compared with non-radical resection for vaginal or cervical melanoma.

Methods: We retrospectively analysed the clinical data of post-operative patients with primary lower genital tract melanoma hospitalised at Peking University Cancer Hospital between Jan 2014 and Dec 2020. The study endpoints were recurrence-free survival (RFS) and overall survival (OS). Kaplan–Meier method-plotted survival curves and univariate and multivariate Cox proportional hazards regression models were used to identify the factors associated with RFS and OS, and to calculate hazard ratios (HRs) and associated 95% confidence intervals (95% CIs).

Results: A total of 80 patients were included. Thirty-one patients had received non-radical resection, and 49 patients had received radical resection. The median patient age was 55.5 (IQR 45.3–60.0) years. Sixty-two (77.5%) patients had vaginal melanoma. Sixty-four patients (80.0%) had received post-operative adjuvant therapy. The median follow-up time was 36.0 months (95% CI 10.1–62.1 months). Sixty-four patients developed recurrence, and 44 patients died. The median RFS (mRFS) was 6.0 months (95% CI 3.4–8.6 m), and the RFS for the radical resection group was longer than that for the non-radical resection group (9.5 vs. 5.3 m), with no significant difference (P > 0.05). The median OS (mOS) was 25.9 months (95% CI 14.4–37.4 m). The mOS was 24.6 months (95% CI 10.3–38.9 m) and 25.9 months (95% CI 10.9–40.9 m) in the non-radical resection group and the radical resection group, respectively. Multivariate Cox regression analysis showed that surgical approach, infiltration depth of the tumour, lymph node metastasis, and post-operative adjuvant therapy were independent risk factors for RFS and that post-operative adjuvant therapy was an independent risk factor for OS.

Conclusion: By performing multivariate analysis, which corrected for potential confounding factors, we identified surgical procedures that were associated with RFS, and we found that RFS and OS in patients with vaginal melanoma and cervical melanoma benefitted from post-operative adjuvant therapy.

Safety Profile of Immunotherapy Combined With Antiangiogenic Therapy in Patients With Melanoma: Analysis of Three Clinical Studies

Objective: To describe the frequency and spectrum of treatment-related adverse events (TRAEs) of immunotherapy combined with antiangiogenic therapy in patients with melanoma. Methods: This retrospective cohort study included three clinical trials on patients with stage III/IV melanoma treated with anti-PD 1 and antiangiogenic therapy. Results: We analyzed data from 72 patients with a median follow-up time of 25.9 months (95% CI, 9.1-42.7 m). The median treatment duration was 7.5 months (range, 0.7-42.8 m), and the median of treatment cycles was 11.0 (range, 1-90). Most patients (70 of 72 or 97.2%) experienced TRAEs (mostly grades 1 or 2). No drug-related deaths were reported. Most TRAEs were hepatic (75%), endocrine (72.2%), skin (65.3%), and gastrointestinal tract (59.7%) manifestations, followed by myelosuppression (55.6%), renal dysfunction (55.6%), and dyslipidaemia (54.2%). The adverse event (AE) spectra were similar between regimens. Using multivariate Cox proportional risk models showed that hypertension was associated with a long PFS. According to our multivariable logistic regression models, TRAEs were not associated with ORR. Conclusion: We found that the prevalence of AEs was higher than that of anti-PD-1 monotherapy. Most of the AEs were mild. The AE spectra were similar to those seen after anti-PD-1 or antiangiogenic therapy monotherapy, without unexpected AEs. Immunotherapy combined with antiangiogenic therapy was well tolerated. Clinical Trial Registration: ClinicalTrials.gov, identifier NCT03955354.

Immunotherapy in Acral and Mucosal Melanoma: Current Status and Future Directions

Acral and mucosal melanomas are extremely rare in Caucasians; however, they are the predominant melanoma subtypes in Asians and other non-Caucasian populations. Acral and mucosal melanomas share many clinicopathological features, including aggressive phenotypes, similar genetic landscapes, and grim prognoses. In spite of advances in melanoma management, patients with acral and mucosal melanomas show limited benefit from current therapies. The rarity of these subtypes of melanoma is a significant factor contributing to the poor understanding of these pathological subtypes and the lack of effective interventions. Furthermore, the mechanisms contributing to disparities between different types of melanoma remain largely unclear. Herein, we comprehensively review current knowledge on the clinicopathological characteristics and mutational landscapes of acral and mucosal melanomas, as well as providing an overview of current therapies for patients with these aggressive melanoma subtypes, focusing on available immunotherapeutic interventions. We also discuss pathological differences between different melanoma subtypes and summarize current knowledge on melanoma disparities between Asians and Caucasians. Finally, we discuss emerging immunotherapeutic strategies for the treatment of acral and mucosal melanomas, focusing on combination therapies with immune checkpoint inhibitors. Unraveling the unique features of acral and mucosal melanomas is key for their early diagnosis and for the development of effective therapies.

PD-L1 expression in malignant melanomas of the skin and gastrointestinal tract

Gastrointestinal melanoma (GM) is a rare but aggressive type of malignant melanoma arising in the gastrointestinal tract. An anti-programmed cell death protein 1 (PD-1) antibody markedly improves prognosis in patients with melanoma. However, little is known regarding the expression of immune-oncology biomarkers in GM compared with skin melanoma (SM), especially in the Asian population. the present study examined clinicopathological characteristics, PD-L1 and HLA expression, and immune-oncology marker expression in 10 cases of GM and 31 cases of SM. Patients with GM exhibited significantly higher incidences of lymph node and distant metastases than patients with SM (P=0.0448 and P=0.0247, respectively). The infiltration of CD8⁺ lymphocytes was significantly higher in GM than in SM (P=0.0231). The infiltration of PD-1⁺ lymphocytes was higher in GM than in SM, but the difference was not significant (P=0.0975). PD-L1-positive melanoma exhibited a higher proportion of BRAF^V600E-positive melanoma than PD-L1-negative melanoma (P=0.0317; 39.4 and 0%, respectively). PD-L1-positive melanoma exhibited significantly higher rates of CD8⁺ and FOXp3⁺ lymphocyte infiltration than PD-L1-negative melanoma (P=0.0221 and P=0.0463, respectively). By contrast, PD-1⁺ lymphocytes did not differ between PD-L1-positive and -negative cases. Furthermore, HLA-positive melanoma exhibited higher proportions of PD-1 (P=0.0101; 53.7 and 15.4%) and CD8 than HLA-negative melanoma (P=0.0818; 66.7 and 38.2%). These results provided useful information regarding tumor immunity in GM and SM and may contribute to the development of treatment strategies for GM.