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Soo Park, MD
Soo Park, MD
Posted: Friday, August 9, 2024
Since a significant percentage of deaths from melanoma are caused by thin melanoma, Pawel Teterycz, MD, PhD, of the Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, and colleagues conducted a study to determine the subgroup of stage pT1bN0 melanoma that demonstrates the worst prognosis. The results of this study, which were presented during the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 9583), suggest that because patients diagnosed with stage IB melanoma exhibit a poor prognosis, further research is warranted.
This study evaluated 665 cases of stage pT1b cutaneous melanoma with negative sentinel node biopsy that were treated between 1998 and 2022 in a high-throughput reference center. Participants were followed for up to 10 years, death, or were lost to follow-up; those alive at the 10-year mark were censored. Individuals were stratified into groups with one or both pT1b features, including Breslow thickness of more than 0.8 mm and/or ulceration.
The median patient age was 49, and 63% of participants were female. Most individuals were classified as pT1b according to Breslow thickness (70%), followed by ulceration (21%) and both features combined (9%). Additionally, 48% of patients had superficial-spreading melanoma, categorized as either nodular (9%) or acral (3%); all other patients had an unspecified subtype. Of note, the median mitotic index was 1 per mm2, which was absent in 46% of cases.
During follow-up, 61 patients died; the overall survival rate at 10 years was 86%. In addition, patients with both IB features (hazard ratio [HR] = 2.1), those who had acral or nodular melanoma (HR = 2.2), and male patients (HR = 2.6) had a worse prognosis, according to multivariable analysis. Of note, the mitotic index was not found to be predictive of overall survival in this instance. Furthermore, those harboring both pT1b features exhibited a 10-year survival rate of 75%; patients with one feature had a 10-year survival rate of 87%.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.
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