1/3Melanoma rates in the U.S. have more than doubled over the last 30 years, now making up 5% of all new cancers 1 .The 4 main subtypes are superficial spreading melanoma (SSM), nodular melanoma (NM), lentigo maligna melanoma (LMM), and acral lentiginous melanoma (ALM), each with different behaviors.Five-year relative survival rates vary: SSM at 99.5%, NM at 74.6%, LMM at 100%, and ALM at 81% 2 .Many factors affect risk of metastasis including Breslow thickness, ulceration, and mitotic rate.Sentinel lymph node status is a crucial prognostic assessment.Despite the many factors identified to aid in risk stratification, data remain limited regarding whether cutaneous melanoma subtype is associated with specific sites of metastasis.This data has been elucidated for ocular melanoma, with the liver being the predominant site of metastasis 3 .Accordingly, our retrospective study provides a descriptive analysis of the distribution of metastasis sites across cutaneous melanoma subtypes and organ specific metastases in a single institution, with consideration of Breslow depth and ulceration status.These findings are exploratory and intended to generate hypotheses rather than establish predictive associations.A retrospective observational study was conducted using data from the University of Arizona's (UA) melanoma database from January 2019 to August 2022.Approved by the University of Arizona Institutional Review Board (Study #00001667), data was collected via REDCap, focusing on melanoma staging, subtype, thickness, ulceration, mitoses, sentinel lymph node metastases, and distant metastases.Eligibility criteria included patients 18 years or older, diagnosed with melanoma, who developed metastases within the study period and received treatment at the UA Cutaneous Oncology Program Clinic in Tucson, Arizona.Exclusions were patients under 18, diagnosed with melanoma in situ or mucosal/ocular melanoma, or having multiple primary invasive melanomas.Statistical analysis was performed using R Core Team (2022) software (Version 4.2.2;R Foundation for Statistical Computing, Vienna, Austria), and the data was visualized using the ggplot2 package 4 .Each patient was considered the unit of analysis.If a patient developed multiple metastatic sites, all locations were recorded.For visualization, each metastatic site is displayed, but proportions in the text are reported at the per-patient level.Of 1,000 patients screened, 32 met inclusion criteria: 56.3% male, 43.8% female, ages 23-87 (median 63.5).Most (97%) were White.The cohort included 32 patients, each serving as the unit of analysis.Six of these patients each had a primary melanoma with multiple, distinct sites of metastasis.Among these, 2 patients had 4 metastatic sites, 2 patients had 3, and 3 patients had 2. The remaining 25 patients had 1 metastatic site each, yielding a total of
Ameneni et al. (Thu,) studied this question.