Acral Lentiginous Melanoma: A Clinicoprognostic Study of 149 Cases at a Single Institution

Objective: The objective of this study is to investigate the epidemiological features, clinical characteristics, and pathological characteristics of acral lentiginous melanoma (ALM) and identify prognostic factors. Methods: A total of 149 patients diagnosed with ALM between August 2008 and December 2019 at the National Cancer Center (NCC) of China were retrospectively analyzed. Follow-up data on patient survival status were collected. Survival curves were generated using the Kaplan-Meier method, and statistical significance was assessed using the logrank test. Additionally, a Cox proportional hazards model was constructed to identify prognostic factors. Results: All patients included in this study were of Chinese ethnicity, with an average age of 52.4 +/- 14.8 years (range, 1580 years) at the time of diagnosis. No gender predilection or genetic susceptibility was observed. The plantar region was the most frequently affected site among primary lesions. Notably, only 17 (11.4%) patients reported a history of trauma. Statistical analysis revealed that a lesion duration of <= 2.5 years, Breslow thickness >4.0 mm, high mitotic rate (>6mm-2), presence of vascular invasion, and regional lymph node metastasis were identified as independent prognostic factors. Conclusion: Our findings indicate that a lesion duration of <= 2.5 years, Breslow thickness >4.0 mm, high mitotic rate (>6 mm(-2)), presence of vascular invasion, and regional lymph node metastasis are significantly associated with a poorer prognosis for patients with ALM.