Prognostic Factors In Determining The Recurrence Of Desmoplastic Melanoma
Sarah Persing, MD, Raysa Cabrejo, BA, Anjela Galan, MD, Stephan Ariyan, MD, James Clune, MD.
Yale School of Medicine, New Haven, CT, USA.
Desmoplastic melanoma is a rare subclass of melanoma with unique clinical implications. Recent advances in immunotherapy have been shown to be highly effective in the treatment of this type of melanoma. Currently, patients with positive sentinel node biopsies may be candidates for adjuvant immunotherapy without a completion lymphadenectomy. Staging in melanoma relies heavily on sentinel lymph node biopsies. The rate of positive sentinel nodes in desmoplastic melanoma is lower than other sybtypes yet rates of visceral recurrence are similar and rates of local recurrenc are actually higher. Therefore, staging desmoplastic melanoma and predicting those that may benefit from upfront check point inhibitor therapy is difficult. The purpose of this study is to identify patients that are likely to have recurrence utilizing pathological characteristics, mutation analysis and sentinel lymph node biopsies and clinical/demographic characteristics. METHODS:
From 1998 to 2017, 109 patients with desmoplastic melanoma underwent treatment in the Yale Melanoma Unit. Of these, 71 patients had sentinel lymph node biopsies. All dermatopathology reports, sentinel lymph node biopsy results, demographics, and clinical outcomes were recorded for all patients. A binomial logistic regression was performed with the coefficients of depth of the initial pathology, age, and the number of positive nodes from the sentinel lymph node biopsy. All statistics were done utilizing SPSS 24. RESULTS:
Desmoplastic melanoma had a recurrence rate of 25% in our cohort. The average age of diagnosis was 69.6 (±13.3) years. The average depth of the desmoplastic melanoma was 4.1 (±3.8) mm. Only 13% of the patients had a positive sentinel lymph node biopsy; 78% of them had complete lymphadenectomies subsequently. Of the patients that had complete lymphadenectomy after a positive sentinel lymph node biopsy, 83% had a recurrence: 40% were intransit and 60% were distant metastasis. The binomial logistic regression calculated an odds ratio of recurrence for depth of 1.03 (p=0.28, CI: 0.82-1.29), for age of 1.07 (p=0.03, CI: 1.01-1.14) and for a positive lymph node of 20.76 (p=0.01, CI: 2.52-171.34). CONCLUSION: In this study, we study pathological characteristics, sentinel lymph node biopsies, and overall clinical outcomes. We found that histological characteristics were not a factor in recurrence. A positive sentinel lymph node biopsy and age were statistically significant factors in determining recurrence. Therefore, it is probably beneficial to provide patients with positive sentinel lymph node biopsies upfront check point inhibitor therapy as a preventative treatment for recurrence. However, we believe that there continues to be a subset of patients that have negative sentinel nodes or no sentinel node biopsy that would benefit for adjuvant immunotherapy. We are currently sequencing the desmoplastic tumors from this study to evaluate for mutations that may predict recurrence better than a sentinel node biopsy.
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