Management of malignant melanoma

Real-world use and outcomes of targeted therapy and immunotherapy for adjuvant treatment of BRAF-mutated melanoma patients in the United States

Using a customized, harmonized US electronic health record database, real-world prescription patterns of first-line adjuvant immunotherapy and targeted therapy were retrospectively assessed for BRAFV600-mutated melanoma. Adults with BRAFV600 mutation-positive stage IIIA-D cutaneous melanoma who received first-line adjuvant immunotherapy (nivolumab or pembrolizumab) or targeted therapy (dabrafenib plus trametinib) between 1 January 2014 and 30 August 2020 in the NOBLE database were included. Patients were followed from first-line adjuvant therapy initiation for at least 6 months, until death, progression, follow-up loss, or data cutoff. Primary endpoints were proportion of patients receiving either therapy in first-line and second-line, treatment switching, treatment timing, and status at the end of first-line therapy. Secondary endpoints included discontinuation rates, recurrence-free survival (RFS), and overall survival (OS). Of 318 patients evaluated, 67.6% received nivolumab, 14.2% pembrolizumab, and 18.2% targeted therapy as first-line adjuvant therapy. Median treatment duration was longest for nivolumab (292 days) and shortest for targeted therapy (115 days). Reason for discontinuation was recorded for 195 of 274 patients who discontinued first-line therapy; most common reasons were treatment completion and treatment-related toxicity [87/158 (55.0%) and 29/158 (18.4%), respectively, in immunotherapy-treated patients; 9/37 (24.3%) and 21/37 (56.8%) in targeted therapy-treated patients]. Median RFS and OS for targeted therapy and nivolumab were not reached and were 34.6 and 38.1 months, respectively, for pembrolizumab. These results inform on prescription preferences and clinical outcomes for BRAFV600-mutated melanoma patients in the first-line adjuvant setting.

Current Controversies in Melanoma Treatment

LEARNING OBJECTIVES

After reading this article and viewing the videos, the participant should be able to: 1. Discuss margins for in situ and invasive disease and describe reconstructive options for wide excision defects, including the keystone flap. 2. Describe a digit-sparing alternative for subungual melanoma. 3. Calculate personalized risk estimates for sentinel node biopsy using predictive nomograms. 4. Describe the indications for lymphadenectomy and describe a technique intended to reduce the risk of lymphedema following lymphadenectomy. 5. Offer options for in-transit melanoma management.

SUMMARY

Melanoma management continues to evolve, and plastic surgeons need to stay at the forefront of advances and controversies. Appropriate margins for in situ and invasive disease require consideration of the trials on which they are based. A workhorse reconstruction option for wide excision defects, particularly in extremities, is the keystone flap. There are alternative surgical approaches to subungual tumors besides amputation. It is now possible to personalize a risk estimate for sentinel node positivity beyond what is available for groups of patients with a given stage of disease. Sentinel node biopsy can be made more accurate and less morbid with novel adjuncts. Positive sentinel node biopsies are now rarely managed with completion lymphadenectomy. Should a patient require lymphadenectomy, immediate lymphatic reconstruction may mitigate the lymphedema risk. Finally, there are minimally invasive modalities for effective control of in-transit recurrences.

Use of Biologic Agents in Extremity Reconstruction

Skin and soft tissue defects of the lower extremity present a unique challenge for the reconstructive surgeon. Successful repair of the lower extremity relies not only on strong anatomical knowledge and surgical expertise, but also on careful consideration of the numerous preoperative factors and indications that may alter the patient's response to operative management. While many of these injuries result from burns, avulsive trauma, diabetes, or vascular insufficiencies, a significant portion can be associated with resection of neoplastic pathologies. This review outlines the uses, indications, and considerations for biologic wound agents in reconstructing skin and soft tissue defects of the lower extremity following Mohs micrographic surgery.

Functional Surgery for Subungual Melanoma: Surgical Tips Based on Histological Analysis of 21 Cadavers

BACKGROUND

Amputation has been the standard treatment for subungual melanoma. Although there is growing attention toward a more conservative functional surgery, specific operative techniques are not yet available.

OBJECTIVE

We aimed to provide objective measurements for use in functional surgery by analyzing the anatomy of the nail apparatus obtained from 21 cadavers.

MATERIALS AND METHODS

Nailbed thickness was histologically measured in each subunit, and skin surface anatomy was evaluated to determine the proximal resection margin. Immunohistochemical staining was performed to analyze microvessel distribution according to the nail subunit.

RESULTS

The nailbed thickness was the thinnest at the most proximal point of the nail matrix (thumbs, 1.10 ± 0.42 mm; big toes, 1.15 ± 0.37 mm) and the thickest at the hyponychium (thumbs, 2.86 ± 0.82 mm; big toes, 2.72 ± 0.84 mm). The distance from the eponychium to the skin surface closest to the bony cortex of extensor tendon insertion was 6.92 ± 5.13 mm in thumbs and 5.14 ± 1.59 mm in big toes. The median microvessel density was the highest at the hyponychium (25.74 vessels/mm2) and lowest at the germinal matrix (16.26 vessels/mm2) (p < .05).

CONCLUSION

This histological study offers practical tips, including those to help decide the proximal and deep resection margins, in functional surgery.

Does acral lentiginous melanoma subtype account for differences in patterns of care in Black patients?

BACKGROUND

Melanoma-specific outcomes for Black patients are worse when compared to non-Hispanic white (NHW) patients. We sought to evaluate whether acral lentiginous melanoma, seen more commonly in Black patients, was associated with racial disparities in outcomes METHODS: The National Cancer Database was analyzed for major subtypes of stage I-IV melanoma diagnosed from 2004 to 2016. The association between Black race and (Siegel et al., Jan) 1 acral melanoma diagnosis and (Bradford et al., Apr) 2 receipt of major amputation for surgical management of melanoma was evaluated using multivariable logistic regression.

RESULTS

251,864 patients were included (1453 Black). Black patients had increased odds of acral melanoma (odds ratio [OR] = 27.6, 95% CI]: 24.4, 31.2) compared to NHW patients. Black patients still had higher odds ratios of major amputation across all stages after adjusting for acral histology and other potential confounders CONCLUSIONS: Increased prevalence of acral melanoma in Black patients does not fully account for increased receipt of major amputation.

Ultrasound-Mediated Microbubble Destruction Suppresses Melanoma Tumor Growth

Melanoma is one of the most aggressive types of cancer, and its incidence has increased rapidly in the past few decades. In this study, we investigated a novel treatment approach, the use of low-intensity ultrasound (2.3 W/cm² at 1 MHz)-mediated Optison microbubble (MB) destruction (UMMD) to treat melanoma in a flank tumor model. The effect of UMMD was first evaluated in the melanoma cell line B16 F10 (B16) in vitro and then in mice inoculated with B16 cells. MB⁺B16 cells were exposed to US in vitro, resulting in significant cell death proportional to duty cycle (R² = 0.74): approximately 30%, 50%, 80% and 80% cell death at 10%, 30%, 50% and 100% DC respectively. Direct implantation of tumors with MBs, followed by sonication, resulted in retarded tumor growth and improved survival (p = 0.0106). Immunohistochemical analyses confirmed the significant changes in expression of the cell proliferation marker Ki67 (p = 0.037) and a microtubule-associated protein 2 (p = 0.048) after US + MB treatment. These results suggest that UMMD could be used as a possible treatment approach in isolated melanoma and has the potential to translate to clinical trials.

The relationship between mitotic rate and depth of invasion in biopsies of malignant melanoma

Background

Malignant melanoma of the skin is a potentially lethal neoplasm that generally originates from atypical melanocytes in the dermal-epidermal junction. When the neoplasm penetrates into the dermis, several variables can affect the extent of its spread, among which depth of invasion has the most important prognostic value. Mitotic rate is another prognostic factor that reflects the biological behavior of the neoplasm.

Objective

This study was designed to evaluate the probable relationship between the depth of invasion of malignant melanoma and its mitotic rate.

Materials and methods

This study was performed on 50 excisional biopsy specimens that had received the diagnosis of malignant melanoma histopathologically. Tumor characteristics including Breslow thickness, Clark level, T-stage, and tumor mitotic rate were recorded.

Results

We observed that at higher Clark levels and higher T-stages, and the mean mitotic rate was significantly increased. Moreover, there was a positive and significant correlation between Breslow thickness and mitotic rate. We demonstrated that one unit increase in mitotic rate was correlated with 0.8 mm increase in Breslow thickness of the tumor.

Conclusion

In malignant melanoma, mitotic activity may probably indicate the depth of tumor invasion. Therefore, in incisional biopsies where depth of invasion cannot be accurately determined, the mitotic activity may be used to estimate Breslow thickness, which is necessary for planning surgical management.

PET Scan Misses Cutaneous Melanoma Metastasis with Significant Tumour Size and Tumour Thickness

BACKGROUND

Although PET-scan is an advanced, innovative and widely used method for monitoring patients with different types of cancer diseases, it is important to note that its application in patients with cutaneous melanoma is limited and should be reconsidered.

CASE REPORT

To affirm this new statement, we are presenting a case from our clinical practice of a patient with melanoma of the interdigital space (with resected in sano primary melanoma and performed complete lymphadenectomy) that showed locoregional and systemic progression in two months post operation. The PET scan performed within the second hospitalization (and before the second operation) did not detect the presence of any cutaneous metastases, which were clinically and histologically verified after the second operative procedure.

CONCLUSIONS

This data suggests that shortly more reliable and sensitive imaging methods for monitoring patients with cutaneous melanoma should be found. Having in mind that our patient has been operated twice in the area of the primary lesion (as the surgical wound underwent secondary healing), theoretically, the abundant cicatrization could have led to reduced glucose uptake in the surrounded cancerous tissue. Monitoring of a larger number of patients with locoregional metastases and surgical interventions in different locations would shed light on the observations shared by us.