Prognostic value of WHO grade in pancreatic neuro-endocrine tumors in Multiple Endocrine Neoplasia type 1: Results from the DutchMEN1 Study Group

• Published in: Pancreatology : official journal of the International Association of Pancreatology (IAP) ... [et al.] 2017-09, Vol.17 (5), p.766-772
• Main Authors: Conemans, Elfi B., Brosens, Lodewijk A.A., Raicu-Ionita, Gabriela M., Pieterman, Carolina R.C., de Herder, Wouter W., Dekkers, Olaf M., Hermus, Ad R., van der Horst-Schrivers, Anouk N., Bisschop, Peter H., Havekes, Bas, Drent, Madeleine L., Timmers, H. Th Marc, Offerhaus, G. Johan, Valk, Gerlof D., Vriens, Menno R.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Epidemiology; Ethics; Eye; Female; Gene expression; Humans; Image processing; Liver; Liver metastases; Male; Medical prognosis; Metastases; Metastasis; Middle Aged; Multiple endocrine neoplasia; Multiple endocrine neoplasia type 1; Multiple Endocrine Neoplasia Type 1 - classification; Multiple Endocrine Neoplasia Type 1 - epidemiology; Multiple Endocrine Neoplasia Type 1 - surgery; Netherlands - epidemiology; Neuroendocrine tumors; Pancreas; Pancreatic cancer; Pancreatic Neoplasms - classification; Pancreatic Neoplasms - epidemiology; Pancreatic Neoplasms - surgery; Pancreatic neuroendocrine tumors; Paraffin; Pathology; Patients; Prognosis; Surgery; Tumors; WHO grade; World Health Organization
• ISSN: 1424-3903; 1424-3911
• DOI: 10.1016/j.pan.2017.07.196

The prognostic value of WHO grade in pancreatic neuroendocrine tumors (PanNETs) in patients with Multiple Endocrine Neoplasia Type 1 (MEN1) is unknown. We performed a cohort study using the Dutch National MEN1 database, which includes >90% of the Dutch MEN1 population with data collected between 1990 and 2014. Formalin-fixed paraffin embedded tissue blocks from the largest resected PanNET per patient were collected. MIB1 staining was performed and KI67 labeling index (LI) was determined by manual eye-counting under a microscope and by digital image analysis. Mitotic count was evaluated from hematoxylin & eosin stains. Association between WHO grade and (time until) development of liver metastases was calculated. Sixty-nine MEN1 patients who underwent pancreatic surgery were included. Ten patients (14%) developed liver metastases and all had PanNETs ≥3 cm. WHO G1, G2 and G3 PanNETs were seen in 83% (n = 57), 16% (n = 11) and 1% (n = 1) respectively. In non-functioning PanNETs >2 cm, liver metastases occurred in 80% of WHO G2 PanNETs (4/5) compared to 23% (5/22) in WHO G1 PanNETs (p = 0.03) when WHO grade was based on mitotic count only. This significant association was not seen for WHO grade based on Ki67 LI. After five years, liver metastases in non-functioning PanNETs were not seen in tumors ≤2 cm, in 10% of the large WHO G1 (according to mitotic count only) tumors and in 60% of large WHO G2 tumors (p-value 0.000). High mitotic count is correlated with poor prognosis in MEN1 patients with large non-functioning PanNETs.