1193P - Evaluation of treatment appropriateness in patients submitted to surgery for non-functioning pancreatic neuroendocrine tumors (NF-PanNETs)

Background

Currently availbale preoperative prognostic factors for non-functioning pancreatic neuroendocrine tumors (NF-PanNETs) still struggle to predict tumor aggressiveness, making an adequate management of these lesions hard to be achieved. Aims of this study were: i) to evaluate treatment appropriateness in patients submitted to surgery for NF-PanNETs, and ii) to investigate preoperative features predicting undertreatment or overtreatment in this setting.

Methods

Patients who underwent curative surgery (R0-R1) for NF-PanNETs at San Raffaele Hospital (2002-2022) were retrospectively analysed. Treatment appropriateness was categorized as appropriate treatment, overtreatment, and undertreatment. The presence of histological features of aggressiveness and the occurrence of disease relapse within one year from surgery were considered to define treatment appropriateness.

Results

Overall, 384 patients were included. Of these, 230 (60%) received an appropriate treatment, 129 (34%) an overtreatment and 25 (6%) an undertreatment. Treatment appropriateness was significantly associated with radiological tumor size (p<0.001), tumor site (p=0.012), surgical technique employed (p<0.001), and year of surgical resection (p<0.001). Surgery performed before 2015 (p<0.001), radiological tumor diameter <25.5mm (p<0.001) and pancreatic body/tail location (p=0.018) were identified as independent predictors of overtreatment. Radiological tumor size was the only independent determinant of undertreatment (p=0.016). Significantly poorer disease-free survival (p<0.001), overall survival (p<0.001) and disease-specific survival (p<0.001) were observed among undertreated patients.

Conclusions

Overtreatment occured in almost one-third of patients undergoing surgery for NF-PanNETs. However, over the last decade, the percentage of appropriately treated patients has been steadily increasing. Surgical management should be carefully considered in presence of lesions located in the pancreatic body-tail and/or measuring <25.5 mm, in order to further improve treatment appropriateness.

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.