Abstract
Objectives Ki-67/MIB-1 is a marker of cellular proliferation used as a pathological parameter in
the clinical assessment of pituitary adenomas, where its expression has shown utility
in predicting the invasiveness of these tumors. However, studies have shown variable
results when using Ki-67/MIB-1 association with recurrence. The purpose of this study is to determine if
a high Ki-67/MIB-1 labeling index (LI) is predictive of recurrence in pituitary adenomas.
Methods A retrospective chart review was performed for patients undergoing pituitary adenoma
resection with at least 1 year of follow-up. Additionally, systematic data searches
were performed and included studies that correlated recurrence rate to Ki-67/MIB-1 LI. Our institutional data were included in a synthesis with previously
published data.
Results Our institutional review included 79 patients with a recurrence rate of 26.6%. We
found that 8.8% of our patients had a high Ki-67/MIB-1 LI (>3%); however, high Ki-67/MIB-1 was not associated with recurrence. The systematic review identified 244
articles and 49 full-text articles that were assessed for eligibility. Quantitative
analysis was performed on 30 articles including our institutional data and 18 studies
reported recurrence by level of Ki-67/MIB-1 LI. Among studies that compared Ki-67/MIB-1 ≥3 vs. <3%, 10 studies reported odds ratios (OR) greater than 1 of which
6 were statistically significant. A high Ki-67/MIB-1 had higher odds of recurrence via the pooled odds ratio (OR = 4.15, 95%
confidence interval [CI]: 2.31–7.42).
Conclusion This systematic review suggests that a high Ki-67/MIB-1 should prompt an increased duration of follow-up due to the higher odds
of recurrence of pituitary adenoma.
Keywords
pituitary adenoma - K
i-67 - MIB-1 - recurrence