December 20, 2018

Current treatment guidelines do not adequately cover what kind of surveillance and treatment should apply to patients with melanoma after a negative sentinel node biopsy.

Measures of ulceration, Breslow thickness, and microsatellitosis in the primary melanoma after a negative sentinel node biopsy (SNB) are predictive of recurrence risk at 1, 2, 5, and 10 years, according to a study published in the Journal of the American Academy of Dermatology.

Current treatment guidelines do not adequately cover what kind of surveillance and treatment should apply to patients with melanoma after a negative SNB, and there is little data on appropriate adjuvant treatments for Stage II patients, even though they are still at risk of recurrence. In the current study, researchers sought to create a nomogram designed to evaluate recurrence risk for patients with a negative SNB based on pathological and clinical characteristics of the primary melanoma. Researchers conducted a retrospective analysis of patients at the Skin Cancer Department of AC Camargo Cancer Center in São Paulo, Brazil, who underwent a SND between 2000 and 2015 (N=1213).

Among those patients, 79.7% (n=967) had a negative SNB. These patients had a mean follow-up of 59.67 months, with 133 melanoma recurrences (13.8%). Forty-five of the 133 recurrences (33.8%) presented with a nodal recurrence, and 35 (26.3%) with a recurrence at the SNB site. Study investigators used the patient data to create a nomogram that assigned points to the 3 most predictive melanoma characteristics (ulceration, Breslow thickness, and microsatellitosis) to determine the probability of survival at 1, 2, 5, and 10 years. 

For example, a hypothetical patient with a primary melanoma tumor that has ulceration (61 points), a 2 mm Breslow thickness (10 points), and does not have microsatellitosis (0 points) would have a total score of 71 points using the nomogram. This can predict that the hypothetical patient has a 90% probability of being recurrence-free after the first year, 77% after year 2, 64% after year 5, and 50% after year 10, with a C-index of 0.749.

Despite the limitations of conducting the analysis at a single treatment center, study investigators concluded they were able to create “a predictive nomogram for melanoma patients after a negative SNB. It is easy to be used and can help both clinicians and patients to provide an individualized follow-up program, as well as to identify high-risk patients who should be considered for adjuvant treatments.”

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Reference

Bertolli E, Petaccia de Macedo M, Calsavara VF, Lopes Pinto CA, Duprat Neto JP. A nomogram to identify high-risk melanoma patients with a negative sentinel node biopsy [published online November 2, 2018]. J Am Acad Dermatol. doi: 10.1016/j.jaad.2018.10.060