Posted: Thursday, August 22, 2024
Alexander M. Menzies, PhD, of the Melanoma Institute Australia, Sydney, and colleagues used fluorodeoxyglucose (FDG)-PET scans to evaluate the changes following neoadjuvant immunotherapy in patients with melanoma to assess the correlation between recurrence-free survival and pathologic response. Presented during the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 9523), the results of this trial seem to support the use of this diagnostic modality in this patient population.
“FDG-PET demonstrates utility in predicting pathologic response and survival with neoadjuvant immunotherapy in melanoma,” concluded the investigators. “PET may identify patients who are not going to be pathologic responders and who have the worst survival outcomes, enabling a potential switch of neoadjuvant systemic therapy.”
This study included 33 patients with stage III, measurable, nodal melanoma from the NeoTrio (n = 13) and NeoPele (n = 20) trials. Patients in both trials received two doses of the PD-1 inhibitor pembrolizumab before surgery, and those in NeoPele also received 5 weeks of the tyrosine kinase inhibitor lenvatinib before surgery. All patients underwent surgery, as well as baseline and 6-week FDG-PET imaging.
The median follow-up was 29.9 months, and nearly half of patients had BRAF mutations (48%). A complete metabolic response was achieved by all patients who also accomplished major pathologic response (n = 8); 14 other patients who obtained partial metabolic response had varying pathologic outcomes. Of the six patients who experienced progressive disease, five had a pathologic nonresponse .
It was reported that PET response correlated with relapse-free survival, since patients demonstrating a complete or near-complete metabolic response had a 100% rate of 24-month relapse-free survival. Furthermore, individuals who had a partial response or stable disease had poor outcomes, with patients who had progressive disease having the worst outcomes (P = .0029).
Disclosure: For full disclosures of the study authors, visit coi.asco.org.