18F-FDG-PET to predict disease progression in advanced digestive neuroendocrine neoplasms

Background

The role of 18F-FDG-PET to predict clinical outcome in advanced digestive neuroendocrine neoplasms (dNENs) is still unclear. The aim is to determine the ability of 18F-FDG-PET to predict DP in patients with advanced dNENs.

Methods

Prospective analysis of consecutive patients with advanced dNENs who performed during a maximum time frame of one month 18F-FDG-PET and CT scan. The analysis of risk factors for prediction of DP during follow-up was performed by uni and multi- variate analysis using a Cox proportional hazards model. Data are expressed as median (IQR). Comparison between subgroups was performed by Fisher test.

Results

60 patients evaluated (46.6% male; median age 59.5). Most frequent primary tumour sites were pancreas (37; 59.6%) and small bowel (19;33.5%). Median Ki67 value was 7% (14; 24.5% had G1 tumours, 34; 54.3% had G2 tumours, and 12; 21% had G3 tumours). 63.2% of patients (n = 36) had positive 18F-FDG-PET. Of these, at time of 18F-FDG-PET examination, 56.1% had a progressive disease, while 7% had a stable disease (p = 0.0001). 36.8% of patients (n = 21) had negative 18F-FDG-PET; of these, at time of 18F-FDG-PET examination, 24.5% had a stable disease, while 12% had a progressive disease (p = 0.05). As far as the grading is concerned, 18F-FDG-PET was positive in 4 patients (28.5%) with G1 dNENs, in 21 patients (61.7%) with G2 dNENs and in all patents (12, 100%) with G3 NEC. Overall median PFS was 8 months (mo). Significantly longer PFS was observed in 18F-FDG-PET negative patients group in comparison with 18F-FDG-PET positive patients group, median PFS being 6 mo (5-9) and 17 mo (8-27), respectively (p

Conclusions

18F-FDG-PET may be considered an accurate non-invasive diagnostic tool able to predict DP in advanced dNENs.

Clinical trial identification

Legal entity responsible for the study

Sapienza University of Rome, Department of Digestive and Liver Disease

Funding

University Sapienza of Rome, Department of Digestive and Liver Disease

Disclosure

All authors have declared no conflicts of interest.