A New Preoperative Scoring System for Predicting Aggressiveness of Non-Functioning Pancreatic Neuroendocrine Neoplasms

Abstract

The management of non-functioning pancreatic neuroendocrine neoplasms (NF-PanNENs) is still controversial. This study aimed to develop a new scoring system for treatment decisions at initial diagnosis based on the identification of the predictive factors for aggressive NF-PanNENs. Seventy-seven patients who had been pathologically diagnosed with NF-PanNENs were enrolled. We retrospectively reviewed 13 variables that could be assessed preoperatively. Univariate and multivariate stepwise logistic regression analyses were performed to identify factors for the aggressiveness of NF-PanNENs, and a scoring system was developed by assigning weighted points proportional to their β regression coefficient. Tumor size > 20 mm on contrast-enhanced computed tomography, tumor non-vascularity, and Ki-67 labeling index ≥5% on endoscopic ultrasound-guided fine-needle aspiration specimens were identified as independent factors for predicting the aggressiveness of NF-PanNENs. The new scoring system, developed using the identified factors, had an excellent discrimination ability, with area under the curve of 0.92 (95% CI, 0.85–0.99), and good calibration (p = 0.72, Hosmer-Lemeshow test). Ten-year overall survival rates in low-risk (0 point), intermediate-risk (1 to 2 points), and high-risk (3 to 4 points) groups were 100%, 90.9%, and 24.3%, respectively. This new scoring system would be useful for treatment decisions and prognostic prediction at initial diagnosis.

Prediction of disease recurrence in patients after complete pancreatic NET G2 resection

“…developed a new preoperative scoring system for predicting aggressiveness of NF-PanNETs. They identi ed tumor size > 2cm on contrast-enhanced CT, tumor non-vascularity, and Ki-67 ≥ 5% on endoscopic ultrasound-guided ne-needle aspiration specimens as independent factors associated with relapse [4]. Genc et al proposed a novel categorization G1/G2 PanNET to predict recurrence after curative resection based on the Ki67 index.…”

“…Of these, the size > 4 cm, Ki-67 > 5% and lymph node metastases proved to be independent predictors [2]. It is worth noting that cases of late relapse even 10 years after curative surgery have been described [4]. 60-90% of PanNETs are hormonally inactive and used to be detected in advanced stages due to an asymptomatic course, which changes with an improvement of diagnostic methods [6].…”

“…However, numerous studies have shown that the prognosis of small localized PanNENs, especially G1 is good and watchful waiting strategy may be an alternative to surgery in patients with small, non-functioning tumors [2,3]. Therefore, the management of non-functioning PanNENs particularly G2 is still controversial [4,5]. Despite evidence of a different malignancy potential of PanNETs G1 and G2, postoperative management is the same in all patients [3].…”

“…If the radical removal of the G1 or G2 tumor is successful, there are no indications for adjuvant chemotherapy. So far, no consistent protocols have been developed based on the likelihood of relapse, although it affects nearly 20% of patients with well-differentiated PanNETs and signi cantly shortens their survival [4]. The Ki-67 value, lymph node involvement and tumor size are essential for prognostic signi cance.…”