Results of NCCTG N0275 (Alliance) - a phase II trial evaluating resection followed by adjuvant radiation therapy for patients with desmoplastic melanoma

Randomized Trial of Postoperative Radiation Therapy After Wide Excision of Neurotropic Melanoma of the Head and Neck (RTN2 Trial 01.09)

BACKGROUND

Cutaneous neurotropic melanoma (NM) of the head and neck (H&N) is prone to local relapse, possibly due to difficulties widely excising the tumor. This trial assessed radiation therapy (RT) to the primary site after local excision.

METHODS

Participants from 15 international centers were randomized to observation or RT. The participants were required to have microscopically negative excision margins 5 mm wide or wider and no evidence of disease elsewhere. The primary outcome was time to local relapse. The secondary outcomes included time to any recurrence, overall survival (OS), and toxicity.

RESULTS

The trial ceased prematurely due to slow recruitment and the COVID-19 pandemic. During 2009-2020, 50 participants were randomized: 23 to observation and 27 to RT. The most common NM subsites were scalp (32%), midface (22%), and lip (20%). The median depth of invasion was 5 mm, and desmoplasia observed in 69%. The median duration from randomization to last contact was 4.8 years. Four participants (8%) experienced local relapse as a first recurrence during the study period: 3 in the observation arm and 1 in the RT arm (hazard ratio [HR] 0.29; 95% confidence interval [CI] 0.03-2.76; p = 0.279). No statistically significant difference in time to any relapse or OS was observed. More than 6 months after randomization, grade 3 or greater toxicity was experienced by 10% of the participants in the observation arm and 12.5% of the participants in the RT arm of the study.

CONCLUSION

Due to low accrual, the role of adjuvant RT for cutaneous NM of the H&N excised with microscopically negative margins 5 mm wide or wider remains undefined. Its routine use cannot be recommended. Local relapse might be less common than previously anticipated based on retrospective reports.

Radiation and Melanoma: Where Are We Now?

PURPOSE OF REVIEW

This review summarizes the current role of radiotherapy for the treatment of cutaneous melanoma in the definitive, adjuvant, and palliative settings, and combinations with immunotherapy and targeted therapies.

RECENT FINDINGS

Definitive radiotherapy may be considered for lentigo maligna if surgery would be disfiguring. High risk, resected melanoma may be treated with adjuvant radiotherapy, but the role is poorly defined since the advent of effective systemic therapies. For patients with metastatic disease, immunotherapy and targeted therapies can be delivered safely in tandem with radiotherapy to improve outcomes. Radiotherapy and modern systemic therapies act in concert to improve outcomes, especially in the metastatic setting. Further prospective data is needed to guide the use of definitive radiotherapy for lentigo maligna and adjuvant radiotherapy for high-risk melanoma in the immunotherapy era. Current evidence does not support an abscopal response or at least identify the conditions necessary to reliably produce one with combinations of radiation and immunotherapy.

Local Recurrence Rates After Excision of Desmoplastic Melanoma: A Systematic Review and Meta-Analysis

BACKGROUND

Few prospective studies have evaluated local recurrence rates (LRR) after excision of desmoplastic melanoma (DM); however, several retrospective studies have reported high LRR.

OBJECTIVE

To determine LRR after excision of DM and evaluate factors affecting LRR.

MATERIALS AND METHODS

Systematic review of the PubMed, Embase, and Web of Science databases was performed to identify studies reporting local recurrence after excision of DM with conventional wide local excision (WLE), Mohs micrographic surgery (MMS), or staged excision (SE). Meta-analysis was performed to calculate summary LRR and pooled risk ratios (RR).

RESULTS

Literature search identified 4 studies evaluating MMS or SE (total n = 61 DM). 53 studies assessed WLE ( n = 3,080) and were analyzed quantitatively. The overall LRR after WLE of DM was 21% (95% CI, 0.16-0.28; n = 2,308). Local recurrence rate was higher with positive/unknown histologic excision margins (49%, 95% CI, 0.25-0.74; n = 91) versus negative histologic margins (11%, 95% CI, 0.07-0.17; n = 1,075; [ p < .01]). Neurotropism was also associated with increased LRR (RR, 1.79; 95% CI, 1.34-2.38, p < .01; n = 644).

CONCLUSION

DM has high LRR after WLE. Local recurrence risk was greatest with positive excision margins, indicating the importance of achieving negative microscopic margins. Greater study of MMS and SE for DM is required.

Current and future approaches in the surgical management of T3b/T4 primary and locoregionally advanced melanoma

Currently accepted principles of surgical management-margin width, use of sentinel node biopsy, performance of radical node dissections for node-positive cases-and some aspects of postoperative management (use of radiation for desmoplastic melanoma primaries and for clinically node-positive disease) will change in the future with the potential widespread adoption of adjuvant and neoadjuvant therapies.

Nasal Mucosal Desmoplastic Melanoma: A Case Report with Review of the Literature

Mucosal melanoma is a rare subtype of melanoma that accounts for 1% of all melanomas. The incidence of nasal mucosal melanomas is 0.3 per million. Desmoplastic melanomas are a subtype of melanoma with a reported incidence of 2.0 per million. Although 50% of desmoplastic melanomas are found in the head and neck region, mucosal desmoplastic melanoma is exceedingly rare. In the present study, we report a case of nasal mucosal desmoplastic melanoma and review the literature. A 79-year-old female presented to an outside otolaryngologist with nasal discomfort accompanied by rhinorrhea and was found to have a nasal vestibule mass. An endonasal incisional biopsy was performed yielding a diagnosis of a SOX-10 positive tumor. The patient was referred to our institution for further management. A blue-tinged lesion was identified at the prior biopsy site, and the mass was resected via an open rhinoplasty approach. Final pathology demonstrated an infiltrative spindle cell neoplasm with immunohistochemical patterns supportive of desmoplastic melanoma arising from the nasal vestibule. Due to positive margins, the patient underwent a re-resection with no tumor identified on the re-resected specimen. To our knowledge, this is the third case of nasal mucosal desmoplastic melanoma. We review the clinicopathologic features and management of this rare entity.

3D printed integrated bolus/headrest for radiation therapy for malignancies involving the posterior scalp and neck

Background

Malignancies of the head and neck region, encompassing cutaneous, mucosal, and sarcomatous histologies, are complex entities to manage, comprising of coordination between surgery, radiation therapy, and systemic therapy. Malignancies of the posterior scalp are particular challenging to treat with radiation therapy, given its irregular contours and anatomy as well as the superficial location of the target volume. Bolus material is commonly used in radiation therapy to ensure that the dose to the skin and subcutaneous tissue is appropriate and adequate, accounting for the buildup effect of megavoltage photon treatment. The use of commercially available bolus material on the posterior scalp potentially creates air gaps between the bolus and posterior scalp.

Case presentations

In this report, we created and utilized a custom 3D-printed integrated bolus and headrest for 5 patients to irradiate malignancies involving the posterior scalp, including those with cutaneous squamous cell carcinoma, melanoma, malignant peripheral nerve sheath tumor, and dermal sarcoma. Treatment setup was consistently reproducible, and patients tolerated treatment well without any unexpected adverse effects.

Conclusions

We found that the use of this custom 3D-printed integrated bolus/headrest allowed for comfortable, consistent, and reproducible treatment set up while minimizing the risk of creating significant air gaps and should be considered in the radiotherapeutic management of patients with posterior scalp malignancies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41205-022-00152-w.

Comparison of Survival Outcomes With/Without Adjuvant Radiation Therapy in Desmoplastic Melanoma

BACKGROUND

Desmoplastic melanoma (DM) is a rare variant of cutaneous melanoma with a high rate of local recurrence. Recent studies have indicated a potential benefit in local control with the addition of adjuvant radiotherapy (RT).

OBJECTIVE

This study sought to evaluate the outcomes of adjuvant RT for patients with DM.

MATERIALS AND METHODS

The National Cancer Database was queried (2004-2015) for patients with newly diagnosed, nonmetastatic DM. Patients were divided into 2 groups based on the adjuvant therapy they received: RT or observation. Statistics included multivariable logistic regression to determine factors predictive of receiving adjuvant RT, Kaplan-Meier analysis to evaluate overall survival (OS), and Cox proportional hazards modeling to determine variables associated with OS.

RESULTS

There was no difference in median OS between patients treated with RT when compared with patients observed (111.4 months vs 133.9 months, p = .1312). On multivariable analysis, older age, T stage ≥2, N stage ≥1, and no receipt of immunotherapy were associated with worse OS.

CONCLUSION

In this large study evaluating efficacy of adjuvant RT in DM, no overall survival benefit was observed among patients receiving adjuvant RT.

Radiation Therapy for Local Cutaneous Melanoma

While primary treatment for melanoma consists of surgical resection and chemotherapeutics, radiation can be used as either definitive or adjuvant therapy in certain clinical scenarios. This chapter aims to explore the indications for primary definitive radiotherapy as well as adjuvant treatment following resection. Delivery, dose, fractionation, and toxicity of radiation treatment will be discussed. As our understanding of melanoma tumor biology increases, the role of radiotherapy may expand for more effective treatment of oligometastatic disease.

Comparing survival outcomes in early stage desmoplastic melanoma with or without adjuvant radiation

Desmoplastic melanoma (DM) due to its rare and locally aggressive nature, can be difficult to study and to treat effectively. Whether the optimal treatment approach for these tumors should include adjuvant radiation has been unclear in the literature. In this retrospective study of the National Cancer Database, 2390 patients with localized DM were included for analysis. 2082 were treated with wide local excision (WLE) and 308 were treated with wide local excision and adjuvant radiation therapy (WLE + RT). Overall survival (OS) in these groups was compared on crude and adjusted analyses utilizing Cox proportional hazards regression modeling. There was no difference in OS at 1, 3, and 5 years on initial analysis. Subsequent multivariate analysis and propensity score analysis showed a survival benefit in those treated with WLE + RT. Multivariate analysis demonstrated significantly decreased OS in cases of residual tumor following surgical excision. Adjuvant radiation was more likely to be performed for tumors on the head and neck, tumors with higher pathologic American Joint Committee on Cancer stage and T classifications, and tumors with positive surgical margins. This is the first study to demonstrate significantly improved OS in early-stage DM patients treated with WLE + RT compared to WLE alone.

Surgical Considerations and Systemic Therapy of Melanoma

Recent advances in effective medical therapies have markedly improved the prognosis for patients with advanced melanoma. This article aims to highlight the current era of integrated multidisciplinary care of patients with advanced melanoma by outlining current approved therapies, including immunotherapy, targeted therapy, radiation therapy, and other strategies used in both the adjuvant and the neoadjuvant setting as well as the evolving role of surgical intervention in the changing landscape of advanced melanoma.

Radiotherapy for Melanoma: More than DNA Damage

Despite its reputation as a radioresistant tumour, there is evidence to support a role for radiotherapy in patients with melanoma and we summarise current clinical practice. Melanoma is a highly immunogenic tumour and in this era of immunotherapy, there is renewed interest in the potential of irradiation, not only as an adjuvant and palliative treatment, but also as an immune stimulant. It has long been known that radiation causes not only DNA strand breaks, apoptosis, and necrosis, but also immunogenic modulation and cell death through the induction of dendritic cells, cell adhesion molecules, death receptors, and tumour-associated antigens, effectively transforming the tumour into an individualised vaccine. This immune response can be enhanced by the application of clinical hyperthermia as evidenced by randomised trial data in patients with melanoma. The large fraction sizes used in cranial radiosurgery and stereotactic body radiotherapy are more immunogenic than conventional fractionation, which provides additional radiobiological justification for these techniques in this disease entity. Given the immune priming effect of radiotherapy, there is a strong but complex biological rationale and an increasing body of evidence for synergy in combination with immune checkpoint inhibitors, which are now first-line therapy in patients with recurrent or metastatic melanoma. There is great potential to increase local control and abscopal effects by combining radiotherapy with both immunotherapy and hyperthermia, and a combination of all three modalities is suggested as the next important trial in this refractory disease.

Re-examining the role of adjuvant radiation therapy

Previously important roles for adjuvant radiotherapy (RT) in melanoma patients included improved regional control after resection of high-risk nodal disease, to reduce local recurrence for desmoplastic, and other subtypes of melanoma with neurotropism, reducing in-brain relapse of brain metastases after surgery and other situations on a case-by-case basis. This review evaluates the integration of adjuvant RT into clinical practice at this time of rapidly evolving knowledge and improving outcomes from effective systemic therapy.

Desmoplastic melanoma

Desmoplastic melanoma (DM) is a rare melanoma variant that has unique biology and pathology compared with conventional melanoma (non-DM). Importantly, DM is classified into pure and mixed histologic subtypes, which have been correlated with outcomes. Management of DM broadly mirrors that of non-DM; however, there are unique considerations for DM that influence treatment approaches. This paper will provide a contemporary overview of this disease and will review the literature regarding the management of DM.

Guidelines of care for the management of primary cutaneous melanoma

The incidence of primary cutaneous melanoma continues to increase each year. Melanoma accounts for the majority of skin cancer-related deaths, but treatment is usually curative following early detection of disease. In this American Academy of Dermatology clinical practice guideline, updated treatment recommendations are provided for patients with primary cutaneous melanoma (American Joint Committee on Cancer stages 0-IIC and pathologic stage III by virtue of a positive sentinel lymph node biopsy). Biopsy techniques for a lesion that is clinically suggestive of melanoma are reviewed, as are recommendations for the histopathologic interpretation of cutaneous melanoma. The use of laboratory, molecular, and imaging tests is examined in the initial work-up of patients with newly diagnosed melanoma and for follow-up of asymptomatic patients. With regard to treatment of primary cutaneous melanoma, recommendations for surgical margins and the concepts of staged excision (including Mohs micrographic surgery) and nonsurgical treatments for melanoma in situ, lentigo maligna type (including topical imiquimod and radiation therapy), are updated. The role of sentinel lymph node biopsy as a staging technique for cutaneous melanoma is described, with recommendations for its use in clinical practice. Finally, current data regarding pregnancy and melanoma, genetic testing for familial melanoma, and management of dermatologic toxicities related to novel targeted agents and immunotherapies for patients with advanced disease are summarized.

Transplantable Melanomas in Hamsters and Gerbils as Models for Human Melanoma. Sensitization in Melanoma Radiotherapy-From Animal Models to Clinical Trials

The focus of the present review is to investigate the role of melanin in the radioprotection of melanoma and attempts to sensitize tumors to radiation by inhibiting melanogenesis. Early studies showed radical scavenging, oxygen consumption and adsorption as mechanisms of melanin radioprotection. Experimental models of melanoma in hamsters and in gerbils are described as well as their use in biochemical and radiobiological studies, including a spontaneously metastasizing ocular model. Some results from in vitro studies on the inhibition of melanogenesis are presented as well as radio-chelation therapy in experimental and clinical settings. In contrast to cutaneous melanoma, uveal melanoma is very successfully treated with radiation, both using photon and proton beams. We point out that the presence or lack of melanin pigmentation should be considered, when choosing therapeutic options, and that both the experimental and clinical data suggest that melanin could be a target for radiosensitizing melanoma cells to increase efficacy of radiotherapy against melanoma.

Results of NCCTG N0275 (Alliance) - a phase II trial evaluating resection followed by adjuvant radiation therapy for patients with desmoplastic melanoma

To examine, in a prospective fashion, the utilization and efficacy of adjuvant radiation therapy (RT) in patients with resected desmoplastic melanoma (DM). Adult patients with resected, margin‐negative, and nonmetastatic DM were eligible for this single‐arm prospective phase II study. Patients were to receive postoperative RT, 30 Gy in five fractions, to the operative bed with 2‐ to 3‐cm margins (depending on the tumor location). Nodal basin RT was not allowed. The primary study endpoint was the 2‐year local recurrence rate (LRR). Secondary endpoints included the incidence of regional and distant metastatic disease, progression‐free survival, overall survival (OS), and treatment‐related toxicity. Twenty patients with a single de novo DM lesion meeting trial eligibility criteria were enrolled and treated. The 2‐year LRR was 10%, with two patients demonstrating a LR within 2 years of completion of protocol therapy. No regional or distant failures occurred. OS at 2 and 5 years was 95 and 77%, respectively. There were no grade 3 or higher acute or late adverse events that were related to the protocol therapy. Adjuvant RT after wide local excision (WLE) for DM is efficacious and well tolerated. It should be considered for DM patients after margin‐negative WLE. Additional study is needed to further refine low‐risk patient populations that can potentially have adjuvant RT omitted as part of the treatment plan.