CD103+ T Lymphocyte Count Linked to the Thickness of Invasion on Acral Melanoma without E-Cadherin Involvement

BACKGROUND: Acral melanoma (AM) is a malignancy that originates from melanocytes, located in an anatomical area without sun exposure, aggressive, resistant to chemotherapy, and quickly metastasize. The invasion capability of tumor cells is the main factor for metastasis in malignancy. E-cadherin is a marker of tumor progressivity that has an important role in the process of invasion. The responsibility of E-cadherin in the invasion process of AM is not well known. CD103 is an immune component found in the tumor microenvironment that contributes to melanoma progression control, whereas E-cadherin is the ligand for CD103. PURPOSE: The objective of this research was to see if there was an association between E-cadherin and CD103 immunoexpression and the thickness of invasion in AM. MATERIALS AND METHODS: This is observational cross-sectional research. Formalin-fixed paraffin-embedded (FFPE) acral melanoma tissue samples were collected during 2014–2020 at the Department of Anatomic Pathology, Dr. Hasan Sadikin Hospital, Bandung. A total of 40 samples were collected, including 20 cases of invasive melanoma less than 4 mm thickness and 20 cases of invasive melanoma greater than 4 mm thickness. All samples were immunostained with E-cadherin and CD103. Chi-Square test was used to examine the association concerning E-cadherin and CD103 with the thickness of invasion, respectively. The p-value of 0.05 was chosen as the significance level. RESULTS: This study showed an insignificant association between E-cadherin immunoexpression and the thickness of invasion on AM (p = 0.4272). CD103 immunoexpression had a significant association with the thickness of invasion on AM (p = 0.0001). CONCLUSION: The findings revealed that CD103 in AM is associated with the thickness of invasion, and it may play important functions throughout the invasion process despite the uninvolvement of E-cadherin.