Omid Fotouhi1, Jan Zedenius2, Anders Höög3, Carl Christofer Juhlin3. 1. German Cancer Consortium (DKTK) partner site Freiburg, German Cancer Research Center (DKFZ) and Department of Urology, Medical Center-University of Freiburg, Germany. 2. Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden. 3. Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden.
Abstract
OBJECTIVE: Somatostatin receptor (SSTR) expression constitutes a pivotal cornerstone for accurate radiological detection and medical treatment of small intestinal neuroendocrine tumors (SI-NETs), and the development of somatostatin analogues for these purposes have revolutionized the clinical work-up. Previous assessments of SSTR isoform expression in SI-NETs have found correlations to overall prognosis and treatment response, however these analyses usually report overall tumoral immunoreactivity, and little is reported regarding histo-regional differences in expressional patterns. METHODS: Thirty-seven primary SI-NETs (WHO grade I, n=32 and WHO grade II, n=5) were collected and assessed for SSTR2 immunohistochemistry. Samples were stratified with regards to histological level of bowel infiltration and spread (mucosal region, muscularis propria region, subserosal region) and each of these tumoral regions was separately scored by SSTR2 staining localization (membrane, cytoplasmic), overall staining intensity and local staining differences within each region. RESULTS: SSTR2 immunoreactivity was progressively weaker as the tumor cells advanced through the small intestinal layers. This was exemplified by a reduction in the amount of tumor samples with strong SSTR2 expression in the deeper histological levels of the section; 56% of tumors displayed strong SSTR2 expression in the mucosal region, as compared to 29% and 30% of tumors within muscularis propria and subserosal layers, respectively. CONCLUSIONS: This observation indicates a down-regulation of SSTR2 expression as the tumors progress through the intestinal wall, which might signify underlying biological processes of importance for SI-NET invasion behavior.
OBJECTIVE: Somatostatin receptor (SSTR) expression constitutes a pivotal cornerstone for accurate radiological detection and medical treatment of small intestinal neuroendocrine tumors (SI-NETs), and the development of somatostatin analogues for these purposes have revolutionized the clinical work-up. Previous assessments of SSTR isoform expression in SI-NETs have found correlations to overall prognosis and treatment response, however these analyses usually report overall tumoral immunoreactivity, and little is reported regarding histo-regional differences in expressional patterns. METHODS: Thirty-seven primary SI-NETs (WHO grade I, n=32 and WHO grade II, n=5) were collected and assessed for SSTR2 immunohistochemistry. Samples were stratified with regards to histological level of bowel infiltration and spread (mucosal region, muscularis propria region, subserosal region) and each of these tumoral regions was separately scored by SSTR2 staining localization (membrane, cytoplasmic), overall staining intensity and local staining differences within each region. RESULTS:SSTR2 immunoreactivity was progressively weaker as the tumor cells advanced through the small intestinal layers. This was exemplified by a reduction in the amount of tumor samples with strong SSTR2 expression in the deeper histological levels of the section; 56% of tumors displayed strong SSTR2 expression in the mucosal region, as compared to 29% and 30% of tumors within muscularis propria and subserosal layers, respectively. CONCLUSIONS: This observation indicates a down-regulation of SSTR2 expression as the tumors progress through the intestinal wall, which might signify underlying biological processes of importance for SI-NET invasion behavior.
Authors: Nina Ionovici; Mara Carsote; Dana Cristina Terzea; Anca Mihaela Predescu; Anne Marie Rauten; Mihaela Popescu Journal: Rom J Morphol Embryol Date: 2020 Apr-Jun Impact factor: 1.033
Authors: Yingnan Si; Seulhee Kim; Jianfa Ou; Yun Lu; Patrick Ernst; Kai Chen; Jason Whitt; Angela M Carter; James M Markert; James A Bibb; Herbert Chen; Lufang Zhou; Renata Jaskula-Sztul; Xiaoguang Margaret Liu Journal: Cancer Gene Ther Date: 2020-07-20 Impact factor: 5.987