Abstract 142P
Background
Immune checkpoint inhibitors (ICI) have improved outcomes in patients with eTNBC. However, irAEs are a major concern in clinical practice. 18F-FDG PET/CT scan is routinely performed for initial staging before neoadjuvant treatment with immunotherapy and chemotherapy (NACT-IO). This study aims to evaluate whether FDG-PET features could predict the occurrence of irAE from NACT-IO in eTNBC.
Methods
We conducted a single-center retrospective study on eTNBC patients treated with NACT and pembrolizumab, between April 2022 and April 2023. Adverse events were recorded and graded according to NCI-CTC AE version 5. Extracted FDG-PET parameters were primary tumor and metastatic loco-regional lymph node-related features (SUVpeak, SUVmax, MVT, TLG, necrosis [only primary tumor]), and healthy organs features (SUVmean of liver, spleen, bone marrow, blood pool, digestive organs, endocrine glands and breasts). Data cut-off date was November 2023. Primary endpoint was the incidence of grade 3-4 irAEs. Logistic regression analysis was performed using R software version 4.1.1.
Results
Of 86 identified patients, 50 had baseline FDG-PET raw data and toxicity data available at our institution. 64% (32/50) of patients experienced any-grade irAEs, and 26% (13/50) severe irAEs. Primary lesion SUVpeak ranged between 1.9 and 27.8 (median: 9.7). 44% (22/50) of primary lesions had central necrosis. 52% (26/50) patients had FDG-avid locoregional lymph nodes. Among the FDG-PET parameters explored, the univariable analysis found a unique significant association between the primary lesion SUVpeak/SUVmax and an increased risk of severe irAE (OR 1.13 IC95 [1.02-1.27]; per unit of SUV). Neither lymph node related features nor healthy organ basal uptake value were associated with severe toxicity.
Conclusions
Our findings suggest that baseline FDG-PET SUVpeak/SUVmax of the primary lesion are significantly associated with an increased risk of severe ICIs irAEs. If these findings are independently validated, baseline FDG-PETmay contribute to personalized risk assessment of irAE in eTNBC, ultimately improving clinical decision-making.
Legal entity responsible for the study
T. Henry.
Funding
Has not received any funding.
Disclosure
J.R. Dixon Douglas: Financial Interests, Other, Travel and accomodation: MSD, Novartis, Pierre Fabre; Financial Interests, Invited Speaker: Gilead Life Sciences . S. Delaloge: Financial Interests, Institutional, Advisory Board: Novartis, Sanofi, Gilead; Financial Interests, Institutional, Invited Speaker: Pfizer, Roche Genentech, BMS, Sanofi; Financial Interests, Institutional, Advisory Board, ad board: Besins Healthcare; Financial Interests, Institutional, Invited Speaker, ESMO symposium: Gilead; Financial Interests, Institutional, Advisory Board, scientific board: Elsan; Non-Financial Interests, Member of Board of Directors, Société Française de Sénologie et Pathologie Mammaire: SFSPM; Non-Financial Interests, Principal Investigator, H2020 funding: European Commission. B. Pistilli: Financial Interests, Institutional, Advisory Board: AstraZeneca, Seagen, Lilly, Daiichi Sankyo, MSD; Financial Interests, Institutional, Invited Speaker: Gilead, Novartis, AstraZeneca, AstraZeneca, Gilead, Seagen, MSD, Novartis, Novartis; Financial Interests, Personal, Advisory Board: Pierre Fabre, Daiichi Sankyo; Financial Interests, Personal, Other, travel support: AstraZeneca, Pierre Fabre, MSD, Daiichi Sankyo; Financial Interests, Personal, Other, Travel support: Pfizer; Financial Interests, Institutional, Research Grant: AstraZeneca; Financial Interests, Institutional, Funding: Daiichi Sankyo; Non-Financial Interests, Project Lead: Unicancer. D. Deandreis: Financial Interests, Personal, Invited Speaker: Novartis; Financial Interests, Personal, Advisory Board, Consensus Document for refractory thyroid cancer: Eisai; Financial Interests, Institutional, Invited Speaker, Trial RADTHYR 2014-2016: Bayer Healthcare. All other authors have declared no conflicts of interest.