Mohs Micrographic Surgery for the Treatment of Cutaneous Melanomas of the Head and Neck

Surgical excision achieving clear histologic margins remains the mainstay treatment for primary cutaneous melanoma. Tumors of the head and neck, particularly those arising in chronically sun-damaged skin, often demonstrate extensive and asymmetric subclinical extension. Over the decades, this has proven to be a significant problem for tumors arising on the head and neck, as anatomic and functional complexities of these areas have led to suboptimal surgical treatment, yielding unacceptably high rates of local recurrence and persistently positive margins with traditional wide local excision. Patients who undergo Mohs micrographic surgery may have improved survival over those who undergo wide local excision.

Development and validation of a nomogram incorporating gene expression profiling and clinical factors for accurate prediction of metastasis in patients with cutaneous melanoma following Mohs micrographic surgery

BACKGROUND

There is a need to improve prognostic accuracy for patients with cutaneous melanoma. A 31-gene expression profile (31-GEP) test uses the molecular biology of primary tumors to identify individual patient metastatic risk.

OBJECTIVE

Develop a nomogram incorporating 31-GEP with relevant clinical factors to improve prognostic accuracy.

METHODS

In an IRB-approved study, 1124 patients from 9 Mohs micrographic surgery centers were prospectively enrolled, treated with Mohs micrographic surgery, and underwent 31-GEP testing. Data from 684 of those patients with at least 1-year follow-up or a metastatic event were included in nomogram development to predict metastatic risk.

RESULTS

Logistic regression modeling of 31-GEP results and T stage provided the simplest nomogram with the lowest Bayesian information criteria score. Validation in an archival cohort (n = 901) demonstrated a significant linear correlation between observed and nomogram-predicted risk of metastasis. The resulting nomogram more accurately predicts the risk for cutaneous melanoma metastasis than T stage or 31-GEP alone.

LIMITATIONS

The patient population is representative of Mohs micrographic surgery centers. Sentinel lymph node biopsy was not performed for most patients and could not be used in the nomogram.

CONCLUSIONS

Integration of 31-GEP and T stage can gain clinically useful prognostic information from data obtained noninvasively.

Association of Treatment Facility Characteristics With Overall Survival After Mohs Micrographic Surgery for T1a-T2a Invasive Melanoma

Importance

Early-stage melanoma, among the most common cancers in the US, is typically treated with wide local excision. However, recent advances in immunohistochemistry have led to an increasing number of these cases being excised via Mohs micrographic surgery (MMS). Although studies of resections for other cancers have reported that facility-level factors are associated with patient outcomes, it is not yet established how these factors may affect outcomes for patients treated with Mohs micrographic surgery.

Objective

To evaluate the association of treatment center academic affiliation and case volume with long-term patient survival after MMS for T1a-T2a invasive melanoma.

Design, Setting, and Participants

In a retrospective cohort study, 4062 adults with nonmetastatic, T1a-T2a melanoma diagnosed from 2004 to 2014 and treated with MMS in the National Cancer Database (NCDB) were identified. The NCDB includes all reportable cases from Commission on Cancer-accredited facilities and is estimated to capture approximately 50% of all incident melanomas in the US. Multivariable survival analyses were conducted using Cox proportional hazards models. Data analysis was conducted from February 27 to August 18, 2020.

Exposures

Treatment facility characteristics.

Main Outcomes and Measures

Overall survival.

Results

The study population included 4062 patients (2213 [54.5%] men; median [SD] age, 60 [16.3] years) treated at 462 centers. Sixty-two centers were top decile-volume facilities (TDVFs), which treated 1757 patients (61.9%). Most TDVFs were academic institutions (37 of 62 [59.7%]). On multivariable analysis, treatment at an academic center was associated with a nearly 30% reduction in hazard of death (hazard ratio, 0.730; 95% CI, 0.596-0.895). In a separate analysis, treatment at TDVFs was also associated with improved survival (hazard ratio, 0.795; 95% CI, 0.648-0.977).

Conclusions and Relevance

In this cohort study, treatment of patients with T1a-T2a invasive melanoma excised with MMS at academic and top decile-volume (≥8 cases per year) facilities was associated with improved long-term survival compared with those excised by MMS at nonacademic and low-volume facilities. Identification and protocolization of the practices of these facilities may help to reduce survival differences between centers.

Slow Mohs Micrographic Surgery for Acral Melanoma Treatment in Korean Patients

BACKGROUND

Obtaining conventional wide surgical margins is challenging in melanomas occurring at anatomically complex sites (e.g., hands and feet).

OBJECTIVE

We investigated the potential benefits of slow Mohs micrographic surgery (MMS) for acral melanomas.

MATERIALS AND METHODS

This single-center retrospective study investigated 210 patients who underwent slow MMS (n = 66) or wide local excision (WLE, n = 144) for melanomas during 2005 to 2015. Slow MMS was used for melanomas in anatomically complex locations and for high-risk lesions.

RESULTS

Acral melanoma (166/210) was the most common lesion observed in patients, in addition to head and neck (21/210) and trunk (23/210) melanomas. Slow MMS was more commonly performed for acral, and head and neck melanomas (32.5% and 52.4%, respectively) than for trunk melanomas (4.3%, p = .002). Local recurrence of acral melanomas occurred in 3.7% of patients after slow MMS and in 10.7% of patients after WLE. Multivariate analysis showed comparable prognostic outcomes between slow MMS and WLE used for acral melanomas. Compared with WLE, slow MMS resulted in a smaller postoperative defect after acral lesion excision (p < .001).

CONCLUSION

Slow MMS is an effective alternative to WLE for acral melanomas in anatomically complex sites, as evidenced by superior outcomes and maximum tissue conservation.