title: Usefulness of the octreotide test in Japanese patients for predicting the presence/absence of somatostatin receptor 2 expression in insulinomas.
abstract: We investigated the relationship between the results of the octreotide test and somatostatin receptor (SSTR) 2 expression in insulinoma patients, to evaluate the usefulness of this test for predicting SSTR2 expression in insulinomas in Japanese patients. Five females and one male were included in the study. All patients underwent the octreotide test before the surgery carried out to resect the tumor, and histopathological examination of the resected tumor was performed by a single experienced pathologist. SSTR2 expression was evaluated by the SSTR2 immunohistochemistry scoring system. Insulinoma was clinically diagnosed and surgically resected in all six patients. In the octreotide test, suppression of insulin secretion was sufficient after loading in patients 1-4 and 6. In patient 5, however, the suppression of insulin secretion was insufficient, which resulted in severe hypoglycemia with endogenous relative hyperinsulinemia after the octreotide loading. The histopathological findings revealed SSTR2 expression in the insulinomas of patients 1-4 and 6, but not in the insulinoma of patient 5. In conclusion, improvement of hyperinsulinemic hypoglycemia by octreotide in Japanese insulinoma patients was associated with SSTR2 expression in the tumor. Our results suggest that the octreotide test could be useful for predicting SSTR2 expression in the tumor.
authors.affiliation: Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Akinobu
authors.initials: A
authors.lastname: Nakamura
authors.forename: Tomoko
authors.initials: T
authors.lastname: Mitsuhashi
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Takano
authors.forename: Hideaki
authors.initials: H
authors.lastname: Miyoshi
authors.forename: Hiraku
authors.initials: H
authors.lastname: Kameda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nomoto
authors.forename: So
authors.initials: S
authors.lastname: Nagai
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hatanaka
authors.forename: Chikara
authors.initials: C
authors.lastname: Shimizu
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Terauchi
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Atsumi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003940:Diagnostic Techniques, Endocrine; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D005951:Glucose Tolerance Test; D006801:Humans; D007340:Insulinoma / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism*; D007564:Japan; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000494:pharmacology* / Q000627:therapeutic use; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism*; D011237:Predictive Value of Tests; D011379:Prognosis; D017481:Receptors, Somatostatin / Q000378:metabolism*
chemical_list: D017481:Receptors, Somatostatin; C574734:SSTR2 protein, human; D015282:Octreotide