Sentinel Lymph Node Biopsy Positivity in Patients With Acral Lentiginous and Other Subtypes of Cutaneous Melanoma

Abstract

IMPORTANCE Acral lentiginous melanoma (ALM) is a rare subtype of malignant melanoma typically occurring on the palmar and plantar surfaces. Although it has distinctive genetic, prognostic, and behavioral characteristics relative to cutaneous melanomas overall, owing to its rarity, treatment is largely guided by data extrapolated from more common subtypes. Although sentinel lymph node (SLN) status has been shown to be a significant prognostic factor for ALM, the independent effect of ALM-subtype disease on the likelihood of SLN positivity and the stage-specific positivity rates for ALM are not well characterized.OBJECTIVE To evaluate the association of ALM with SLN status as well as to characterize the clinical stage-specific rates of SLN positivity for ALM based on the AJCC Cancer Staging Manual, 8th edition (AJCC-8). DESIGN, SETTING, AND PARTICIPANTSThe National Cancer Database (NCDB) includes all reportable cases from Commission on Cancer accredited facilities and represents approximately 50% of all newly diagnosed melanoma cases in the US. This retrospective cohort study included cases of AJCC-8 clinical stage I to II melanomas from the NCDB diagnosed from 2012 to 2015. The analysis took place between April 2021 and September 2021.EXPOSURES Melanoma histopathologic subtype. MAIN OUTCOMES AND MEASURES Sentinel lymph node status. RESULTSWe identified 60 148 patients with malignant melanomas, 959 of whom had ALM-subtype disease. Among patients in the cohort, 25 550 (42.5%) were women and the mean (SD) age was 64 (16) years. Multivariable logistic regression controlling for demographic and histopathologic characteristics revealed that ALM was independently associated with the highest risk for SLN positivity among included subtypes (vs superficial spreading melanoma: odds ratio, 1.91; 95% CI, 1.59-2.28). Subgroup analysis by AJCC clinical stage demonstrated that ALM was independently associated with the highest risk for SLN positivity for both stage IB and II disease. The rate of SLN positivity for patients with stage IB and II ALM was 18.39% (95% CI, 13.82%-24.03%) and 39.53% (34.98%-44.26%), respectively. CONCLUSIONS AND RELEVANCEIn this cohort study ALM was independently associated with SLN positivity and had relatively high positivity rates at clinical stage IB and II. This suggests that SLNB should be encouraged for all patients with clinical stage IB and II ALM, and such patients should receive appropriate counseling about the higher regional metastatic risk of their cancers. Future work with a larger cohort is required to elucidate the risk of SLN positivity for stage IA ALM.

Clinical characteristics, survival analysis and influencing factors of distant metastasis in patients with acromelanomas: A retrospective study

“…This distant metastasis characteristic of AM is often one of the important factors for poor prognosis of patients. [21] The prognosis of AM also depends on a variety of other factors, including region, race, gender, age, etc, [1] as well as the stage of cancer at the time of diagnosis, [1] Breslow thickness, [22] combined ulcers, [23] pathological stage, [24] and sentinel lymph node positive [25] and the overall health status of the individual. Studies have shown that, [26] sentinel lymph node positive is the strongest predictor of melanoma disease recurrence and death.…”

Assessing Rates of Positive Surgical Margins After Standard Excision of Vulvar Melanomas

“…7 The risk for a positive sentinel node may also be higher for some specialty site melanomas; although data are minimal for vulvar melanomas, recent work has demonstrated very high rates of positive sentinel nodes in patients with acral melanoma. 50 With patients who have regional disease becoming eligible for potentially lifesaving adjuvant immunotherapy, this is an important part of an adequate staging workup based on a tumor's T stage. [51][52][53][54] MMS is typically an in-office procedure and SLNB is typically performed in the operating room concurrently with excision of the primary tumor, as was performed in 84.3% of cases in our analysis, the logistical coordination of SLNB before MMS is a potential limitation to the use of MMS for vulvar melanoma.…”

Role of Sentinel Lymph Node Biopsy for Skin Cancer Based on Clinical Studies

“…The risk of SLN metastases may differ among subtypes of melanoma. In a retrospective study comparing the rate of positive SLNB results among subtypes of melanoma (SSM, LMM, ALM, NM, and others), ALM was independently associated with the highest risk for positive SLNB results, whereas LMM was associated with the lowest risk among the included subtypes [ 44 ]. A subgroup analysis demonstrated that ALM was also independently associated with the highest risk for positivity of SLNB results in both stage IB and stage II disease [ 44 ].…”

“…In a retrospective study comparing the rate of positive SLNB results among subtypes of melanoma (SSM, LMM, ALM, NM, and others), ALM was independently associated with the highest risk for positive SLNB results, whereas LMM was associated with the lowest risk among the included subtypes [ 44 ]. A subgroup analysis demonstrated that ALM was also independently associated with the highest risk for positivity of SLNB results in both stage IB and stage II disease [ 44 ]. These results suggest that SLNB should be more encouraged for patients with ALM than for those with the other subtypes, especially in cases of stage IB or stage II disease.…”