Endocrine Abstracts

Craniopharyngiomas (CP) are low-prevalent tumors characterized for their local invasiveness and poor clinical outcomes, often requiring aggressive therapeutic measures. Ki67 is a marker of proliferation with good correlation with tumor recurrence in many solid tumors but this relationship is unclear in CP. Our aim is to determine whether Ki67 could be a marker for recurrence in CP.

Material and methods: Descriptive retrospective observational study. All patients with confirmed histology of CP and tissue sample available for immunohistochemical analysis admitted to the Endocrinology Department from Virgen Del Rocio University Hospital (Seville, Spain) from January 2000 to December 2013 were included. Immunohistochemical analysis for Ki67 was performed on tumor samples following standard procedures. Tumors were in 2 groups according to the Ki67 proliferation index (number of positive cells per high power field score: Group A (Ki67<10%) and group B (Ki67>10%). Quantitative variables are expressed as Median [Interquartile Range], while qualitative ones are expressed as number of patients/patients with available data (percentage). As all variables followed a non-parametric distribution (Demonstrated by Shapiro-Wilks and Kolmogorov-Smirnov tests when appropriate), Chi-Square, Fisher’s exact test and Z-test with Benjamini-Hochberg correction were used when needed. A p-value <0.05 was considered as significant.

Results: Our study population included 29 patients (12 male and 17 female), with a median age at diagnosis of 28.5 years [IQR7.25-46.00]. 12 were children (under 18 years old), and 17 adults (older than 18). A higher tumor recurrence rate was found in tumors with Ki67 proliferative index >10%, 8/9 (88.9%) in comparison with Ki67<10% (6/15, 40.0%, P=0.019). In children, six tumors display Ki67<10% and 6 Ki67>10%; recurrences were observed in 2/6 (33.3%) in the first group and in 6/6 (100%) in the second, respectively (P=0.061). In adults, 9 tumors displayed Ki67<10% and 3 patients Ki67>10% (in 5 patients, no reliable data could be obtained); recurrences were observed in 4/9 (44.4%) in the first group and in 2/3 (66.7%) in the second, respectively (P=1,000). There were no differences between age groups.

Conclusions: In our series, CP with Ki67 proliferative index >10% are more likely to recur; sub-analysis per age group shows the same pattern. These findings support the use of Ki67 as a marker for recurrence in CP.