Abstract: Background and purpose: Acral melanoma (AM) is common in China, and the prognosis is poor. The purpose of this study was to analyze the clinical features, treatment methods and therapeutic effects, and to explore the related factors for poor prognosis of AM. Methods: We collected the clinical data of 322 patients with AM from January 2010 to December 2017. The clinical characteristics and prognostic factors of AM were analyzed. Results: AM was more common in peasants (66%) and workers (12%). About 70.5% of the lesions were located in the sole of the foot. The ratio of male and female was 1.3∶1.0, and the median age was 58 years. There was no difference in distribution among various regions of Hunan Province. Local physical stimulation and inflammation were closely related to the occurrence of AM. The prognosis of the patients undergoing standard operation in stage Ⅱ-Ⅲ was significantly better compared with those without surgical treatment. For the plantar melanoma, the necrosis and infection rate of medial plantar artery flap was lower than that of sural neurovascular flap. The time to distant metastasis was longer in postoperative patients receiving systemic adjuvant therapy than in patients without adjuvant therapy. Survival rate of stage Ⅳ patients with chemotherapy was higher than that of patients without chemotherapy. The patients in stage Ⅳ had higher lactic dehydrogenase (LDH) compared with the patients in stage Ⅰ-Ⅲ, while the survival rate of patients with LDH≥281 U/L was lower. The 5-year survival rate of patients with AM was 66%, and the median survival time was 69.4 months. Gender, age, tumor site, duration of the lesion, satellite lesion, LDH, erythrocyte sedimentation rate (ESR) and Ki-67 were used as multivariate analysis. The results showed that tumor site, duration of the lesion, LDH and Ki-67 were independent risk factors for prognosis. Conclusion: AM is more common in peasants and workers, and most of the lesions are located in the sole of the foot. Standard surgical treatment and systemic adjuvant therapy can improve the prognosis of the patients. The tumor site, duration of the lesion, LDH and Ki-67 labelling index are the independent risk factors affecting the prognosis of patients.

Key words: Acral melanoma, Clinical characteristics, Prognosis