The diameter of cutaneous melanoma serves as a prognostic indicator for survival among acral-melanoma predominant East Asian patients.

ABSTRACT

BACKGROUND: Tumor staging plays a pivotal role in melanoma management, where the depth of tumor invasion has been traditionally used as the cornerstone of staging. Paradoxically, the tumor diameter has not been integrated into the staging system. The aim of this study is to elucidate the clinical implications and prognostic value of tumor diameter in cutaneous melanoma, with a particular emphasis on the acral-melanoma predominant East Asian population, thus potentially enriching the clinical evaluation and treatment strategies for cutaneous melanoma. METHODS: From January 1st, 2006 to December 31st, 2022, a total of 352 patients were diagnosed with melanoma in our center. Among them, there were 135 patients diagnosed as cutaneous melanoma who received complete surgical wide excision and regional lymph nodes assessment. The diameter of the tumor, the depth of tumor invasion, lymph node status and patient survival were all collected and analyzed. RESULTS: The diameter of cutaneous melanoma had a weak positive correlation with tumor thickness (r = 0.26), however, it still had a significant predictive value for patients' overall survival (p = 0.005) and disease free survival (p = 0.023). As for lymph node metastasis prediction, the Breslow thickness had a better predictive value than tumor diameter (p = 0.002 vs. p = 0.565). CONCLUSIONS: In this study, though with only weak positive correlation to tumor thickness, the tumor diameter of melanoma showed a statistically significant correlation with the patients' overall survival and disease free survival. However, the larger tumor diameter cannot be used as an indicator of high risk of lymph node metastasis.