Histopathological and Immunophenotypic Changes of Pancreatic Neuroendocrine Tumors after Neoadjuvant Peptide Receptor Radionuclide Therapy (PRRT)

Marco Schiavo Lena, Stefano Partelli, Paola Castelli, Valentina Andreasi, Chanel Elisha Smart, Eleonora Pisa, Mirco Bartolomei, Emilio Bertani, Giuseppe Zamboni, Massimo Falconi, Claudio Doglioni

Research output: Contribution to journalArticlepeer-review

Abstract

Peptide Receptor Radionuclide Therapy (PRRT) is an emerging therapeutic option for pancreatic neuroendocrine tumors (PanNETs). A possible role for PRRT as a neoadjuvant agent is still largely undetermined, explored only in case reports or small case series. Likewise, the histopathological and immunophenotypic changes induced by PRRT are poorly characterized. In the present study, 24 patients who underwent neoadjuvant PRRT on the basis of their disease’s characteristics were retrospectively matched with 24 patients who underwent upfront surgery. A comprehensive morphological and immunohistochemical evaluation was conducted to identify the differences in the two groups. The most significant findings were that the total percentage of stroma increased significantly in patients who underwent PRRT (p < 0.0001) and the characteristics of the stroma were different in the two groups. The somatostatin receptors type 2A (SSTR2A) were retained in most patients (87%) after PRRT. The density of CD163+ M2-polarized macrophages was greater in the PRRT group (p = 0.022), and M2-polarized macrophages tended to assume an epithelioid morphology (p = 0.043). In the neoadjuvant PRRT group, none of the histological parameters considered were associated with progression-free survival (PFS). Neoadjuvant PRRT in PanNETs is associated with reduced tumor diameter, an increased percentage of stroma, preserved SSTR2A expression in most of the cases, and an increased CD163+ M2-polarized macrophages density.

Original languageEnglish
Pages (from-to)119-131
Number of pages13
JournalEndocrine Pathology
Volume31
Issue number2
DOIs
Publication statusPublished - Jun 1 2020

Keywords

  • Immunohistochemistry
  • M2-polarized macrophages
  • Pancreatic neuroendocrine tumor
  • Peptide Receptor Radionuclide Therapy
  • Response to neoadjuvant therapy

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Endocrinology, Diabetes and Metabolism
  • Endocrinology

Fingerprint Dive into the research topics of 'Histopathological and Immunophenotypic Changes of Pancreatic Neuroendocrine Tumors after Neoadjuvant Peptide Receptor Radionuclide Therapy (PRRT)'. Together they form a unique fingerprint.

Cite this