Outcomes of Melanoma In Situ Treated With Mohs Micrographic Surgery Compared With Wide Local Excision

Surgical Management of Primary Cutaneous Melanoma

Primary cutaneous melanomas are potentially curative with surgical excision alone. Surgical management is based on several factors determined from the initial biopsy, including primary tumor thickness, histologic features including ulceration, and anatomic location. Cosmesis, although important, should be a secondary consideration as oncologic principles take precedence. Pathology has evolved to synoptic reporting with key variables to assist in staging and risk stratification.

Upstaging of melanoma in situ and lentigo maligna treated with Mohs micrographic surgery rarely results in additional surgical management

As Mohs micrographic surgery (MMS) is more widely utilized for melanoma in situ (MIS) and lentigo maligna (LM), there is increasing concern over whether the procedure can negatively affect the treatment of upstaged tumors. Previous studies have shown that about 1-2% of MIS/LM treated with MMS require sentinel lymph node biopsy, but little is still known regarding surgical outcomes. We performed a retrospective chart review of 117 MIS/LM lesions treated with MMS at Brigham and Women's Hospital. We found a low rate of tumor upstaging (8.5% or 10/117), and only 1.7% (2/117) required wide local excision and sentinel lymph node biopsy. In both patients, there was successful location of the sentinel nodes by surgical oncologists. This study highlights the low risk of MIS/LM upstaging, with the majority changing to T1a, and the low need for further surgical management after MMS. Collaboration with other surgical specialties ensures appropriate management of patients with upstaged tumors.

Improved overall survival of melanoma of the head and neck treated with Mohs micrographic surgery versus wide local excision

BACKGROUND

Optimal surgical management for melanoma of the head and neck remains controversial.

OBJECTIVE

Assess outcomes for melanomas of the head and neck treated with Mohs micrographic surgery (MMS) versus wide local excision (WLE) from the National Cancer Database.

METHODS

Head and neck melanoma data from the National Cancer Database from years 2004-2015 were analyzed.

RESULTS

In total, 50,397 cases of head and neck melanoma were reviewed; 3510 (7%) were treated with MMS and 46,887 (93%) with WLE. After controlling for potential confounding variables, patients treated with MMS were more likely than patients treated with WLE to survive after 5 years (hazard ratio [HR] 1.181, 95% confidence interval [CI] 1.083-1.288; P < .001). Factors associated with a statistically significant survival disadvantage included male sex (HR 1.287, 95% CI 1.242-1.357; P = 0), tumor ulceration (HR 1.687, 95% CI 1.616-1.760; P = 0), and positive surgical margins (HR 1.395, 95% CI 1.306-1.490; P = 0). Patient survival was inversely proportional to tumor Breslow depth.

LIMITATIONS

Database study, limited number of MMS treated melanomas.

CONCLUSION

MMS is a valid treatment option for melanoma of the head and neck; National Cancer Database data suggests that MMS might confer a survival benefit over WLE.

Is melanocyte density our last hope? Comparison of histologic features of photodamaged skin and melanoma in situ after staged surgical excision with concurrent scouting biopsies

Differentiating melanocytic hyperplasia (MH) on photodamaged skin from junctional lentiginous melanocytic proliferations (JLMP), early evolving melanoma in situ (MIS), or the periphery of a lesion of MIS on staged excision can be challenging. Although previous cross-sectional studies have elucidated important criteria for distinguishing MH on photodamaged skin from more concerning lesions, this study highlights a technique to treat JLMP and MIS with staged mapped excision and baseline scouting biopsies of adjacent nonlesional photodamaged skin to assist in determination of surgical margin clearance. Additionally, we compare the lesional and photodamaged control biopsies from the same patient to evaluate relevant histologic criteria that may be used to distinguish MH in photodamaged skin from JLMP/MIS, while minimizing confounding factors. There was a statistically significant difference (P ≤ 0.05) found for melanocyte density, irregular melanocyte distribution, melanocyte clustering, follicular infundibulum involvement, and nesting. However, criteria such as nesting, epithelioid cells and melanocyte clustering were seen in both photodamaged skin and MIS. These findings underscore the fact that histologic features of photodamaged skin can overlap with the histopathological features of MIS. Of all of the criteria evaluated, melanocytic density was the most objective histologic criterion and did not show overlap between the sun-damaged and JLMP/MIS groups.

Update on Current Treatment Recommendations for Primary Cutaneous Melanoma

Primary cutaneous melanoma describes any primary melanoma lesion of the skin that does not have evidence of metastatic disease. This article reviews the current workup, treatment, and follow-up recommendations for primary cutaneous melanoma (stages 0, I, and II). Specific attention is focused on recent updates with regard to staging, sentinel lymph node biopsy, and surgical modalities.

Mohs micrographic surgery versus wide local excision for head and neck melanoma-in-situ

Background: Various surgical options can be used to remove melanoma in situ (MIS). These include wide local excision (WLE), staged excision, and Mohs micrographic surgery (MMS). For MIS lesions located in the head and neck regions, the WLE approach may not always be a technically feasible option if both cosmesis and anatomical function is to be preserved.Methods: We performed a retrospective analysis of the Surveillance, Epidemiology, and End Results (SEERs) cancer registry. A total of 7933 cases of MIS in the head and neck region were included in this study, of which 5353 cases were treated by WLE and the remaining 2580 cases by MMS.Results: Comparing between the WLE and MMS group, cancer-specific survival rates at 5 (99% vs. 99%) and 10 years (98% vs. 98%) as well as the 5 year overall survival rate (85% vs. 86%) were similar. After adjusting for confounders, there was no significant difference in cancer-specific survival (HR: 0.902, 95% confidence interval (CI): 0.539-1.511, p = .695) and overall-survival (HR: 0.943, 0.813-1.093, p = .435).Conclusions: For cosmetic and functional purposes, MMS is a valid and suitable alternative to WLE to treat MIS due to its tissue-preserving nature particularly in the head and neck region.Key PointsOur adjusted analysis demonstrates similar overall and cancer-specific survival for Mohs surgery vs wide local excision for head and neck melanoma-in-situFor cosmetic and functional purposes, MMS is a valid and suitable alternative to WLE to treat MISThis is due to its tissue-preserving nature particularly in the head and neck region.

Comparison of surgical margins for lentigo maligna versus melanoma in situ

BACKGROUND

Multiple studies have shown a 5-mm surgical margin to be inadequate for excision of melanoma in situ. Some have suggested that a wider margin is needed only for the lentigo maligna subtype.

OBJECTIVE

To compare subclinical extension of lentigo maligna with that of melanoma in situ. The secondary objective was to investigate the effect of other factors on extent of subclinical extension.

METHODS

A prospectively collected series of noninvasive melanomas was studied. Original pathology reports were used to identify lentigo maligna and compare data for that subtype with data for the remaining melanomas in situ.

RESULTS

A total of 1506 lentigo maligna cases and 829 melanomas in situ were included. To obtain a 97% clearance rate, both lentigo maligna and melanoma in situ required a 12-mm margin on the head and neck and a 9-mm margin on the trunk and extremities. Only 79% of lentigo maligna and 83% of melanoma in situ were successfully excised with a 6-mm margin (P = .12). Local recurrence was identified in 0.26% (5 facial, 1 scalp, and 1 acral), with a mean follow-up time of 5.7 years.

LIMITATIONS

Margins less than 6 mm were not studied. The use of lentigo maligna diagnosis was not used by all dermatopathologists consistently. The degree of surrounding photodamage was not assessed.

CONCLUSION

Subclinical extension of lentigo maligna and melanoma in situ are similar. Standard surgical excision of all melanoma in situ subtypes, including lentigo maligna, should include at least 9 mm of normal-appearing skin, which is similar to the amount recommended for early invasive melanoma. Lesions on the head and neck or those with a diameter greater than 1 cm may require even wider margins and are best treated with Mohs micrographic surgery. The perception that lentigo maligna has wider subclinical extension may be related to its frequent location on the head and neck, where photodamage can camouflage the clinical border.

Rapid liquid biopsy for Mohs surgery: rare target cell separation from surgical margin lavage fluid with a high recovery rate and selectivity

In melanoma surgery, it is difficult to identify residual scattered tumor cells at the surgical margin because of invasive growth. Mohs surgery, widely applied to increase the cure rate and decrease the recurrence rate of melanoma, involves examination of the tissue for tumor cells after tissue removal. Here, we established a liquid biopsy platform for rapid (<5 h), sensitive examination of residual tumor cells at the margin after Mohs surgery using clinical samples from patients with pigment nevus for a demonstration. The design involved highly sensitive, selective rare target cell separation from surgical margin lavage fluid (SMLF) through micropore-arrayed filtration. High recovery rates (86.7% ± 16.3% and 72.7% ± 46.7%, respectively) for separation of spiked 5 A375s (cultured human melanoma cells) and 1 A375 from 1 mL PBS were achieved for this platform. Detection of SMLF samples from patients with pigment nevus was performed, and many (66-7420) Melan-A-positive target cells were successfully recovered and identified, demonstrating the application performance of this rapid liquid biopsy for Mohs surgery in clinical practice. Moreover, a high-selectivity separation of larger target A375 cells from smaller background Jurkat cells was achieved with a high enrichment factor (4.2 ± 1.1). In clinical practice, high selectivity contributes to effective depletion of red blood cells (RBCs), thus ensuring verification of target cells from samples with severe RBC contamination. Furthermore, target cells were obtained with high purity (2.7-35.2%). The capability of this method for rare-cell separation with a high recovery rate and good selectivity may facilitate improvement of performance of Mohs surgery for real clinical practice, including shortening examination time and increasing detection sensitivity.

Benefit of Mohs Micrographic Surgery Over Wide Local Excision for Melanoma of the Head and Neck: A Rational Approach to Treatment

BACKGROUND

There are limited published data comparing wide local excision (WLE) with Mohs micrographic surgery (MMS) for the treatment of melanoma.

OBJECTIVE

To describe a novel treatment algorithm for the surgical management of head and neck melanoma and compare rates of local recurrence for tumors treated with either MMS using immunohistochemistry or WLE.

MATERIALS AND METHODS

A 10-year retrospective chart review including all in situ and invasive melanomas of the head and neck treated at one institution from January 2004 to June 2013.

RESULTS

Among 388 patients with melanoma, MMS was associated with decreased rates of local recurrence (p = .0012). However, patient and tumor characteristics varied significantly, and WLE subgroup was largely composed of higher stage and risk tumors. Subgroup analysis found that patients with in situ or thin invasive tumors (<0.8 mm) treated with MMS had improved local recurrence outcomes (p = .0049), despite more frequent tumor location on high risk anatomic sites (e.g., central face). In addition, MMS was associated with a favorable delay in time to local recurrence among in situ tumors (HR = 31.8; p = .0148).

CONCLUSION

These findings further support the use of MMS for treatment of melanoma of the head and neck and help to validate our proposed clinical decision tree.

Mohs Micrographic Surgery: Past, Present, and Future

BACKGROUND

Mohs micrographic surgery (MMS) is a frequently used technique that provides total margin visualization for treatment of skin neoplasms.

OBJECTIVE

To provide a comprehensive review of MMS literature, focusing on its origins, evidence behind present-day uses of MMS, and future directions.

METHODS

A literature search was conducted using PubMed to identify articles pertaining to MMS.

RESULTS

The fresh frozen technique led to widespread use of MMS in the 1970s. One randomized controlled trial and several large prospective studies have demonstrated low recurrence rates for treatment of nonmelanoma skin cancer (NMSC). MMS, when compared with surgical excision, also achieved a statistically significant higher cure rate for treatment of recurrent NMSC. Studies have demonstrated low recurrence for the treatment of melanoma and melanoma in situ with MMS. MMS has also been shown to effectively treat several rare cutaneous neoplasms. The future of MMS is likely to include the adoption of noninvasive imaging, immunostaining, and digital technology.

CONCLUSION

Mohs micrographic surgery is an effective treatment modality for numerous cutaneous neoplasms. It has achieved statistically significant superiority to surgical excision for the treatment of recurrent and high-risk NMSC. The future is likely to see increased use of noninvasive imaging, immunostaining, and digital technology.

Management of Early-Stage Melanoma

Melanoma is a potentially aggressive skin cancer with a steadily rising incidence. Most melanomas are diagnosed at an early stage and associated with an excellent prognosis when treated appropriately. Primary treatment for melanoma is surgical. Wider surgical margins and a variety of techniques for comprehensive histologic margin assessment may be considered for lentigo maligna type melanoma on the head and neck, due to characteristic broad subclinical extension. For invasive melanoma, sentinel lymph node biopsy may be indicated for staging, and to guide further management and follow-up. Appropriate treatment guidelines for early-stage melanoma are reviewed and discussed.

Patient indications for Mohs micrographic surgery: a clinical practice guideline

Objective

The purpose of the present work was to develop evidence-based indications for Mohs micrographic surgery in patients with a diagnosis of skin cancer.

Methods

The guideline was developed by Cancer Care Ontario's Program in Evidence-Based Care, together with the Melanoma Disease Site Group and the Surgical Oncology Program, through a systematic review of relevant literature, patient- and caregiver-specific consultation, and internal and external reviews.

Recommendation 1

Given a lack of high-quality, comparative evidence, surgery (with postoperative or intraoperative margin assessment) or radiation (for those who are ineligible for surgery) should remain the standard of care for patients with skin cancer.

Recommendation 2

Mohs micrographic surgery is recommended for patients with histologically confirmed recurrent basal cell carcinoma of the face and is appropriate for primary basal cell carcinomas of the face that are larger than 1 cm, have aggressive histology, or are located on the H zone of the face.

Recommendation 3

Mohs micrographic surgery should be performed by physicians who have completed a degree in medicine or equivalent, including a Royal College of Physicians and Surgeons of Canada Specialist Certificate or equivalent, and have received advanced training in Mohs micrographic surgery.

NEO412: A temozolomide analog with transdermal activity in melanoma in vitro and in vivo

Despite new treatments introduced over the past several years, metastatic melanoma remains difficult to cure. Although melanoma in situ (MIS) has better prognosis, it relies heavily on thorough surgical excision, where ill-defined margins can pose a challenge to successful removal, potentially leading to invasive melanoma. As well, MIS in the head and neck area can create serious aesthetic concerns with regard to the surgical defect and substantial scar formation. Toward improved treatment of localized melanoma, including the targeting of unrecognized invasive components, we have been studying a novel agent, NEO412, designed for transdermal application. NEO412 is a tripartite agent that was created by covalent conjugation of three bioactive agents: temozolomide (TMZ, an alkylating agent), perillyl alcohol (POH, a naturally occurring monoterpene with anticancer properties), and linoleic acid (LA, an omega-6 essential fatty acid). We investigated the anti-melanoma potency of NEO412 in vitro and in mouse models in vivo. The in vitro results showed that NEO412 effectively killed melanoma cells, including TMZ-resistant and BRAF mutant ones, through DNA alkylation and subsequent apoptosis. in vivo, NEO412 inhibited tumor growth when applied topically to the skin of tumor-bearing animals, and this effect involved a combination of increased tumor cell death with decreased blood vessel development. At the same time, drug-treated mice continued to thrive, and there was no apparent damage to normal skin in response to daily drug applications. Combined, our results present NEO412 as a potentially promising new treatment for cutaneous melanoma, in particular MIS, deserving of further study.

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.

Patient Indications for Mohs Micrographic Surgery: A Systematic Review

The purpose of the present review was to describe evidence-based indications for Mohs micrographic surgery (MMS) in patients with a diagnosis of skin cancer. Relevant studies were identified from a systematic MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews search of studies published from 1970 to 2017. Randomized controlled trials (RCTs), prospective and retrospective comparative studies with greater than 30 patients, and single-arm retrospective studies with multivariate analyses were included. A total of 2 RCTs, 3 prospective studies, and 16 retrospective studies (14 comparative and 2 single-arm) were included. Data on recurrence rate, cure rate, complications, cosmesis, and quality of life were extracted. Surgery (with postoperative or intraoperative marginal assessment) or radiation for those who are ineligible for surgery should remain the standard of care for patients with skin cancer given the lack of high-quality, comparative evidence. MMS is recommended for those with histologically confirmed recurrent basal cell carcinoma (BCC) of the face and is appropriate for primary BCCs of the face that are >1 cm, have aggressive histology, or are located on the H zone of the face. The available evidence is difficult to generalize to all patients with skin cancer because the evidence did not adequately cover non-BCC skin cancers; however, those skin cancers can be considered on a case-by-case basis for MMS. MMS should be performed by physicians who have completed a degree in medicine or equivalent, including a Royal College of Physicians and Surgeons of Canada Specialist Certificate or equivalent, and have received advanced training in MMS.

Current perspectives on Mohs micrographic surgery for melanoma

Mohs micrographic surgery (MMS), a specialized surgical excision technique used primarily in the treatment of skin cancers, is tissue sparing and provides optimal margin control through evaluation of 100% of both the peripheral and deep margin. The use of MMS for the treatment of malignant melanoma (MM) and melanoma in situ (MIS) has been slow in gaining the same widespread acceptance that it has for keratinocyte carcinomas despite its cost-effectiveness and the growing body of evidence demonstrating similar or improved cure rates to standard wide local excision. However, modern advances in immunohistochemical staining have continued to greatly enhance the ability of Mohs surgeons to interpret MMS frozen sections of melanoma specimens – the primary concern of most opponents of MMS for melanoma. These advances, coupled with an increased recognition by professional organizations of the utility of MMS in treating MM and MIS, have led to a rise in the use of MMS for melanoma in recent years. Given the expanding role of MMS in the treatment of cutaneous melanoma, this manuscript will describe how MMS is performed, discuss the rationale and current evidence regarding the use of MMS for MM and MIS, review the immunohistochemical stains currently available for use in MMS, and consider special situations and future directions in this area of growing interest.