Narrow Excision Versus Wide Excision for the Treatment of Adults With Invasive Cutaneous Melanoma, ICEMAN Trial

Inclusion Criteria:

* Participants or legally authorized representatives (LAR) must provide written informed consent before any study-specific procedures or interventions are performed
* Age ≥ 18 years; all biological gender identities and racial/ethnic groups will be included
* Participants must have histologically confirmed primary cutaneous melanoma. Acral melanomas are eligible.
* Participants must have one of the following:

  * American Joint Committee on Cancer (AJCC) 8th Ed clinical stage IA disease with Breslow thickness \> 0.5 mm AND at least one high-risk feature (Mitotic rate ≥ 2/mm2, age ≤ 42, lymphovascular invasion, head/neck location)
  * AJCC 8th Ed Clinical Stage IB melanoma

    * If a melanoma is widely transected and the true Breslow depth is uncertain, then to be eligible for this trial, the melanoma must be re-biopsied to ascertain an accurate Breslow depth.
* The index melanoma must be classified as low risk on the Merlin Assay (SkylineDx)
* Study intervention (surgery) must be completed within 120 days of the original diagnostic biopsy
* Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2 (Karnofsky ≥ 50%)
* Patients with a prior or concurrent malignancy whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen are eligible for this trial
* Participants with a history of HIV infection are eligible
* Participants can speak, read and write in English or Spanish

Exclusion Criteria:

* Uncertain diagnosis of melanoma (i.e. severely dysplastic nevi, melanocytic lesion of unknown malignant potential, atypical intraepidermal melanocytic proliferations)
* The patient has already undergone wide local excision at the site of the primary index lesion
* The patient has a pure desmoplastic melanoma. A pure desmoplastic melanoma is defined as being \> 90% desmoplastic type. Melanomas with \< 90% desmoplastic type may be included in this trial
* Mucosal and ocular melanomas are also excluded, as these are approached differently for surgical excision
* Physical, clinical, radiographic, or pathologic evidence of satellite, in-transit, regional, or distant metastatic melanoma
* Participants with known or suspected cancer with regional or distant metastasis are excluded from this clinical trial because this trial is aimed at evaluating the control of localized disease
* The patient has undergone surgery on a separate occasion to clear the lymph nodes of the probable draining lymphatic field, including a sentinel lymph node biopsy, of the index melanoma
* Planned adjuvant radiotherapy to the primary melanoma site after excision
* Participant is unwilling or unable to comply with study procedures