Can the Ki-67 Labeling Index in Biopsy Specimens Predict the World Health Organization Grade of Rectal Neuroendocrine Tumors?

Dig Dis. 2018;36(2):118-122. doi: 10.1159/000484083. Epub 2017 Oct 31.

Abstract

Background: Being grade 2 is a known risk factor for metastasis in rectal neuroendocrine tumors (R-NETs). We aimed to identify the efficacy of the Ki-67 labeling index (LI) in endoscopic biopsy specimens to predict the World Health Organization (WHO) grade of R-NETs.

Methods: A total of 59 patients with 60 R-NETs (43 WHO grade 1 and 17 WHO grade 2), treated between October 2002 and December 2014, were retrospectively evaluated. The patients included in the study underwent biopsies followed by endoscopic submucosal resection with a ligation device, trans-anal full-thickness surgical resection, or radical surgery with lymph node dissection. The Ki-67 LI in the biopsy and resected specimens were compared between the 2 tumor grade groups, and the diagnostic sensitivity, specificity, and positive and negative predictive values for the detection of WHO grade 2 tumors were evaluated.

Results: The sensitivity, specificity, and positive and negative predictive values of the Ki-67 LI in biopsy specimens for predicting grade 2 tumors were 53% (9 of 17), 95% (41 of 43), 100% (9 of 9), and 87% (41 of 47), respectively. Pearson's rank correlation coefficient between the Ki-67 LI in the biopsy and resected specimens was 0.92.

Conclusions: The Ki-67 LI of the biopsy specimen is useful for determining the appropriate treatment for R-NETs.

Keywords: Biopsy; Ki-67 labeling index; Neuroendocrine tumor; Rectum; World Health Organization grade.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biopsy*
  • Female
  • Humans
  • Ki-67 Antigen / metabolism*
  • Male
  • Middle Aged
  • Neoplasm Grading
  • Neuroendocrine Tumors / metabolism*
  • Neuroendocrine Tumors / pathology*
  • Predictive Value of Tests
  • Rectal Neoplasms / metabolism*
  • Rectal Neoplasms / pathology*
  • Rectal Neoplasms / surgery
  • Rectum / metabolism
  • Rectum / pathology
  • Retrospective Studies
  • Sensitivity and Specificity
  • Staining and Labeling*
  • World Health Organization*

Substances

  • Ki-67 Antigen