Abstract PS3-19: Prognostic value of textural associated with metabolic parameters of baseline 18FDG-PET/CT in early triple-negative breast cancer (TNBC)

Abstract

Background : Triple negative breast cancer (TNBC) represents 10-17 % of all diagnosed early breast cancers, occurs more frequently in young women (< 50 years old) and has a poor prognosis. TNBC remains a clinical and therapeutic challenge dealing with a paradox: a high-risk of metastatic relapse despite a high rate of clinical and histological response after neoadjuvant chemotherapy with contrasting but disappointing results of targeted therapies. However, TNBCs are treated as a single entity and due to their phenotypic heterogeneity and various molecular pathogenesis, this subtype has a very different profile in terms of prognosis and response to treatment. Positron emission tomography/computed tomography (PET/CT) with 18F-fluorodeoxyglucose (18FDG) is gaining importance for the staging of patients with large or locally advanced breast cancer. TNBCs often show high 18FDG uptake and several studies demonstrate correlations between standard uptake value (SUV) and histoprognostic factors such as grade or KI67%. Recently, a new approach is growing interest in medical imaging: textural analysis. Some studies have shown correlations between metabolic parameters with overall survival (OS) and disease free survival (DFS) in other carcinoma, such as lung and head-and-neck cancers. Few studies analyzed textural features with potentially promising prognostic value that has to be confirmed. The objective of this study is to evaluate the association between metabolic and textural parameters measured at the initial 18FDG-PET/CT, disease-free survival (DFS) and overall survival (OS) in patients with non-metastatic TBNC. Patients and Methods: All consecutive non-metastatic TNBC women who underwent 18FDG-PET/CT at diagnosis between 2012 and 2018 were retrospectively included. Metabolic parameters (SUVmax, SUVmean, SUVpeak, MTV, TLG) in the primary tumor and lymph nodes and textural features (entropy, homogeneity, SRE, LRE, LGZE, HGZE) in the primary tumor were collected. Regression models were used to assess the correlations between PET parameters and histoprognostic factors. Cox regression models were computed to identify association with DFS and OS. Results : One hundred and eleven patients were enrolled. The median follow-up was 53.6 months. Thirty-six patients experienced relapse and 20 died. Homogeneity was associated with no axillary lymph node involvement and lower grade. Entropy was associated with higher grade, lymph node involvement and inflammatory tumors. SRE was only associated with higher grade. TLG and MTV were highly correlated (r =0.98, 95%CI = 0.97-0.99). TLG, MTV and Entropy of the primary tumor were associated with lower DFS (p = 0.008, p = 0.006, and p = 0.025, respectively) and lower OS (p = 0.002, p = 0.001 and p = 0.046, respectively). In the 50 patients with positive PET axillary lymph nodes, all metabolic parameters except SUVmean were correlated with DFS whereas no correlation was seen with OS. Conclusion: Textural associated with metabolic features of baseline 18FDG-PET/CT add prognosis value interesting to identify high risk group of relapse in early TNBC patients. Citation Format: Clément Bouron, Clara Mathie, Valérie Seegers, Camille Guillerminet, Mario Campone, Olivier Morel, Pascal Jézéquel, Anne Patsouris, Aude Testard. Prognostic value of textural associated with metabolic parameters of baseline 18FDG-PET/CT in early triple-negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS3-19.