Table 3 A summary of the main clinical features, molecular pathology, and immune microenvironmental characteristics of acral melanoma
Characteristics | Classification | Results/Conclusions | Ref. |
|---|---|---|---|
Clinical characteristics | Etiology | Trauma may promote the development of extremity melanoma | |
Gender | Men may have a worse prognosis compared to women | ||
Anatomic subsite | The poorer prognosis of AM might be more closely related to the anatomical site than the histological subtype | ||
Molecular pathology characteristics | Chromosomal structural variations and copy number variations | Compared to CM, AM has more chromosomal structural variations and CNVs Common copy number amplified genes include CCND1, GAB2, PAK1, TERT, YAP1, MDM2, CDK4, NOTCH2, KIT, and EP300; common copy number deletion regions, including those containing CDKN2A and NF1 and PTEN | |
Driver mutations | the proportion of TWT mutations is higher in AM than in CM (38% vs. 11%) | [60] | |
Immune microenvironmental characteristics | TILs | AM has a suppressive immune microenvironment compared to CM (CD 8 + T cell, NK cells, and γδ T cells) | |
M2-Ms | the density of M2-Ms is higher in the ALM tumor microenvironment compared to SSM | [85] | |
PD-L1 | Lower levels of PD-L1 are present in AM than in chronic sun-damaged melanoma (31% vs. 62%) | [92] |