Prognostic significance of regression and mitotic rate in head and neck cutaneous melanoma

Abstract

Importance While regression is a commonly reported microscopic feature of melanoma, its prognostic significance is unclear. Objective To examine the impact of regression on sentinel node status and the likelihood of recurrence in primary cutaneous melanoma of the head and neck. Design Retrospective analysis of 191 adults who underwent surgical management for primary cutaneous melanoma of the head and neck between May 2002 and March 2019. Setting Tertiary academic center. Participants Patients appropriate for the study were identified by the Academic Health Center Information Exchange using a list of current procedural terminology codes. One hundred and ninety‐one cases of invasive melanoma of the head and neck were included from 830 patients identified. Clinical features assessed for each patient included age, sex, location of primary lesion, date of diagnosis, and current disease status (alive with or without disease). Histologic features assessed were histological melanoma subtype (nodular vs non‐nodular), Breslow thickness, Clark level, presence/absence of ulceration, mitotic rate per square millimeter, and regression. If applicable, sentinel lymph node biopsy (SLNB) status, date of recurrence, interval treatments, and date of death related to melanoma were recorded. Exclusion criteria included melanoma outside the anatomic parameters of head and neck, ocular or choroidal melanoma, mucosal melanoma, metastatic melanoma to the head or neck with no known primary tumor, melanoma of the head or neck with no surgical intervention, and non‐melanoma skin cancers of the head and neck. Intervention/Exposure Surgery for cutaneous melanoma of the head and neck. Main Outcome(s) and Measure(s) The association between presence of regression and Breslow thickness, sentinel node status, and recurrence. Results Of the 191 patients identified, 30.9% were female and 69.1% were male with a mean age at diagnosis of 62.6 (range 20‐97) years. Mean Breslow thickness was 1.2 mm in those with regression and 2.0 mm in those without regression. In patients with regression, 17.6% had a positive sentinel node, and 13.0% experienced a recurrence. In patients without regression, 26.5% had a positive sentinel node, and 31.4% experienced a recurrence. When adjusted for other factors above, regression was not associated with positive sentinel node (odds ratio [OR] = 0.59, 95% confidence interval [CI] = 0.13‐2.00) or recurrence (OR = 0.33, CI = 0.07‐1.01). Mitotic rate >2 was associated with recurrence (OR = 2.71, CI = 1.11‐6.75, P = .03). Conclusions and Relevance Patients with presence of regression had thinner melanomas and trended toward decreased rates of sentinel node positivity and recurrence, suggesting regression may not be a negative prognostic indicator in patients with cutaneous melanoma of the head and neck.

Head–neck melanoma: Clinical, histopathological and prognostic features of an Italian multicentric study

“…A higher proportion of in situ cases (49.6%), in particular LMM, with mean Breslow thickness 2.18 versus 1.77 mm was found. In a retrospective analysis of 191 HNM, regression was associated with thinner Breslow, decreased rates of sentinel node positivity, and lower recurrence, suggesting that regression may not be a negative prognostic indicator of HNM 29 …”

“…In a review of the literature, it has been shown that in HNM, the main risk factors associated with a reduction in OS and DFS were age, sex, and anatomical site 17 . Patients over 65 years of age had a lower 5‐year survival rate compared with younger patients; males had a worse prognosis than females, and the scalp region had the worst prognosis, also being an independent prognostic indicator 23–30 …”

“…In a retrospective analysis of 191 HNM, regression was associated with thinner Breslow, decreased rates of sentinel node positivity, and lower recurrence, suggesting that regression may not be a negative prognostic indicator of HNM. 29 The mean survival time from diagnosis of 143 patients was 37.15 ± 33.91 months and a significantly shorter survival time was observed for patients with posterior neck HNMs. The other patients were followed up for a mean time of 40.69 ± 41.12 months.…”

“…17 Patients over 65 years of age had a lower 5-year survival rate compared with younger patients; males had a worse prognosis than females, and the scalp region had the worst prognosis, also being an independent prognostic indicator. [23][24][25][26][27][28][29][30] As regards surviving, no significant differences have been highlighted between different sites, in the sub-population considered; this result is probably strongly influenced by the overall small number of cases and the high number of censored data.…”