Abstract 46P
Background
18F fluorodesoxyglucose (18F FDG) positron emission tomography (PET/CT) has emerged as a tool able to predict prognosis in many neoplasms. In adrenocortical cancer (ACC), 18F FDG/CT is widely used for diagnosis and staging; its prognostic role, however, needs to be explored. This study aimed to investigate the prognostic role of 18F FDG PET/CT parameters in ACC patients treated with first-line chemotherapy in terms of PFS and OS.
Methods
This retrospective monocentric study included metastatic ACC patients treated with chemotherapy after 18F FDG PET/CT staging. Clinicopathological features and PET/CT semiquantitative parameters such as standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), SUVmax/liver ratio (SL) and SUVmax/blood-pool ratio (SBP) were collected. T-test and Kruskal-Wallis test were used to assess the relationship between these parameters. Cox regression models were performed to identify prognostic factors in terms of progression free (PFS) and overall survival (OS).
Results
Forty-one patients were included. Median PFS was 9.3 months and median OS was 14.3 months. Lower MTV (HR 0.36, CI 0.17-0.74; p = 0.006), lower TLG (HR 0.31, CI 0.15-0.64; p = 0.002), lower tumour burden (HR 0.45, CI 0.23-0.94; p = 0.03) and reaching mitotane therapeutic concentration (HR 0.45, CI 0.21-0.99; p = 0.05) attained the statistical significance in univariate analysis in terms of longer PFS while lower PLR was at the limit of statistical significance (HR 2.09, CI 1.06-4.36, p = 0.06). Lower TLG (HR 0.33, CI 0.13-0.82; p = 0.004) confirmed its independent role in the multivariate analysis. At univariate analysis, lower MTV (HR 0.36, CI 0.16-0.82; p = 0.01), lower TLG (HR 0.30, CI 0.12-0.69; p = 0.005) and mitotane in range during treatment (HR 0.30, CI 0.13-0.73; p = 0.008) correlated with longer OS while lower tumour burden was near the statistical significance value (HR 0.48, CI 0.21-1.07; p = 0.07). Lower TLG did not achieve statistical significance as an independent prognostic factor in terms of OS in the multivariate analysis.
Conclusions
Pretreatment TLG assessed with 18F FDG PET/CT was reported as an independent predictive tool for ACC patients treated with first-line chemotherapy.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.