Korean J Dermatol.  2022 Dec;60(10):657-665.

Immunohistochemical Expression of Yes-Associated Protein in Koreans with Acral Melanomas

• Kim SM
• Kim D
• Kwon IS
• Shin JM
• Hong D
• Jung KE
• Kim CD
• Lee Y
• Seo YJ
• Park S

Abstract

Background
Acral melanoma is the most common subtype of melanoma among Koreans, and regional or distant metastasis is an indicator of poor prognosis. Yes-associated protein (YAP), a key effector of the Hippo pathway, is known to induce tumor progression and metastasis in various cancers.
Objective
We aimed to analyze the clinical and histopathological characteristics of acral melanoma among Koreans and to evaluate their association with YAP expression.
Methods
This retrospective review included 27 patients with acral melanoma. Clinical features including age, sex, lesion site, and stage were obtained from the medical records and images. Biopsy slides of patients with acral melanoma were reviewed, and immunohistochemical staining for YAP was performed.
Results
The rate of YAP expression was significantly higher in patients having acral melanoma with regional or distant lymph node (LN) metastasis than in those without metastasis (n=4/5, 80.0% vs. n=2/22, 9.1%; p=0.004). Histopathologically, the rate of YAP expression was higher in patients having acral melanoma with lymphovascular invasion than in those without lymphovascular invasion (n=4/8, 50.0% vs. n=2/19, 10.5%; p=0.044). Among the 27 lesions, 14 (51.9%) were on stress-bearing sites such as the forefoot and heel. However, the rate of YAP expression did not differ significantly between weight-bearing and non-weight-bearing locations (p=0.834).
Conclusion
YAP expression is significantly associated with metastasis, especially LN metastasis, in patients with acral melanoma. Therefore, YAP expression may be used as a prognostic factor for LN metastasis and a target for novel treatments in patients with melanoma.

Keyword

Acral melanoma; Lymph node metastasis; YAP