|
Back to 2015 Annual Meeting Program
Cellular Proliferation Does Not Correlate With Octreotide Scintigraphy Findings in GI Neuroendocrine Tumors
Samantha L. Savitch*1, Hetal N. Trivedi2, Matthew E. Maeder2, Samuel J. Wahl2, Stephen Scharf2, Stephen Machnicki2, Solaiman Futuri2, Joanne Weiskopf1, Paresh C. Shah1
1NYU Langone Medical Center, New York, NY; 2Lenox Hill Hospital, New York, NY
Objective: To assess if a correlation exists between ki-67 cellular proliferation index and the detectable uptake during octreotide scintigraphy in neuroendocrine tumors of the gastrointestinal tract.
Methods: This is a single institution retrospective study of patients diagnosed with a neuroendocrine (NET) or carcinoid tumor of the gastrointestinal tract who also had octreotide scintigraphy scans performed between 2006 and 2013. Ki-67 index as reported on pathology was correlated to the scintigraphy findings. A ki-67 index of ≤10% was considered low, while those >10% were considered high. Subset analysis was performed according to tumor location and tumor size, as well as biopsy or resection status. Statistical analysis was performed using Chi-squared and linear regression analyses.
Results: A total of 573 patients were diagnosed with a neuroendocrine tumor of the gastrointestinal tract. Of these, 214 patients had octreotide scans performed as either their initial staging or subsequent follow-up. From this group, 55 patients for whom ki-67 indices were available were included in the final analysis. 40% of patients had positive, localizing uptake on octreotide scintigraphy (O+), while 60% had no uptake (O-). 78% of patients had a low ki-67 index and 22% had a high index. There was no difference in the likelihood of scan positivity between low and high index groups (40% of all low index patients were O+, 42% of all high index patients were O+). There was also no difference in likelihood of high index between the scan positive and negative groups (23% of O+ were high index, 21% of O- were high index). All tumors ≤2cm in size were low index and 23% were O+. 75% of tumors >2cm were low index, and 38% were O+. 36 patients had extra-pancreatic (EP) tumors. Of these, 36% were O+, 64% O-, 78% had a low index, and 22% had a high index. Of EP patients with a low index, 40% were O+. Of EP patients with a high index, 25% were O+. This was not a statistically significant difference. The ratios of O+ and index levels were not significantly different within any of the subgroups (all p>0.30).
Conclusion: While both histology and nuclear medicine are useful tools in the management of neuroendocrine and carcinoid tumors of the gastrointestinal tract, cellular proliferation as measured by the ki-67 index does not correlate with the likelihood of uptake on octreotide scintigraphy scan.
Back to 2015 Annual Meeting Program
|
