INFLUENCE OF LYMPHATIC, MICROVASCULAR AND PERINEURIAL INVASION ON ONCOLOGICAL OUTCOME IN PATIENTS WITH SMALL INTESTINAL NEUROENDOCRINE TUMORS

AUTHORS:
F. Butz (Berlin, Germany) , A. Dukaczewska (Berlin, Germany) , L. Reinhard (Berlin, Germany) , J. Krömer (Berlin, Germany) , C. Müller-Debus (Berlin, Germany) , T. Skachko (Berlin, Germany) , H. Jann (Berlin, Germany) , U. Fehrenbach (Berlin, Germany) , C. Kunze (Berlin, Germany) , J. Pratschke (Berlin, Germany) , P. Goretzki (Berlin, Germany) , M. Mogl (Berlin, Germany) , E. Dobrindt (Berlin, Germany)
Background:
Lymphatic (LI), microvascular (VI), and perineural (PnI) invasion have been identified as indicators of aggressive tumor behavior and poor outcome in many solid tumors. The determination of LI, VI and PnI is also recommended for histopathologic evaluation of resected neuroendocrine tumors of the small intestine (siNET), but their association with oncologic prognosis has not been fully evaluated.
Methods:
A retrospective analysis of all patients treated with siNET at the ENETS Center of Excellence Charité - Universitätsmedizin Berlin from 2010 to 2020 was performed (n=510), excluding patients who did not undergo primary resection or had G3 tumors.
Results:
In the overall cohort (n=161), distant metastases were more frequent in patients with LI, VI and PnI status (48.0% vs. 72.4%, p=0.004; 47.1% vs. 84.4%, p<0. 001; 34.2% vs. 84.7%, p<0.001), while curative surgery rates were lower (58.0% vs. 21.0%, p<0.001; 48.3% vs. 16.7%, p<0.001; 68.4% vs. 14.3%, p<0.001). In addition, progression-free survival, but not overall survival, was significantly reduced in patients with LI, VI or PnI compared to those without. This was also demonstrated in patients who underwent curative surgery.
Conclusions:
As lymphatic, microvascular and perineural invasion led to earlier disease recurrence and postoperative disease progression, we promote the routine evaluation of these histopathologic parameters and their consideration in treatment and follow-up decisions in patients with siNET.