Japan Digestive Disease Week 2025
International Poster Session16 (JDDW)
October 31, 15:44–16:16, Room 15 (Kobe International Exhibition Hall No.1 Building Digital Poster Venue)
IP-79_S
Immune reaction after PRRT in neuroendocrine tumor (NET) patients
- 1
- Department of Hepatobiliary and Pancreatic Surgery, Institute of Science Tokyo
- 2
- Department of Oncology Yokohama City University Graduate School of Medicine
Background: Peptide receptor radionuclide therapy (PRRT) is a new treatment strategy for somatostatin receptor (SSTR) positive neuroendocrine tumor (NET), which is internal radiotherapy targeting SSTR on the tumor cell surface. NET is known to be less immunogenic tumor with few immune cell infiltrations; therefore, immune checkpoint inhibitor (ICI) is not effective. On the other hand, external radiotherapy has shown to induce abscopal effect, where not only irradiated site, but also non-irradiated metastatic site is shrunk due to immune reaction after radiotherapy. Therefore, we hypothesized that PRRT can induce immune reaction in NET patients.
Methods: To test this hypothesis, we investigated serum cytokine change by cytokine array in NET patients who received PRRT. 12 pairs of serum from 9 patients were examined.
Results: 9 pairs were from pre and post PRRT serum of 1st PRRT. 1 pair was from 2nd PRRT, remaining 2 were comparison pre and post whole course of PRRT. The results showed that, among 36 examined cytokines, only 12 were detectable by the cytokine array. Of those, CD154 showed significant changes in 7 pairs, in which 6 were downregulated and 1 was upregulated. IL-1ra was also upregulated in 3 pairs.
Conclusion: We found that PRRT induce systemic cytokine change. Further study is needed to clarify the mechanism of the detected cytokine changes.
Methods: To test this hypothesis, we investigated serum cytokine change by cytokine array in NET patients who received PRRT. 12 pairs of serum from 9 patients were examined.
Results: 9 pairs were from pre and post PRRT serum of 1st PRRT. 1 pair was from 2nd PRRT, remaining 2 were comparison pre and post whole course of PRRT. The results showed that, among 36 examined cytokines, only 12 were detectable by the cytokine array. Of those, CD154 showed significant changes in 7 pairs, in which 6 were downregulated and 1 was upregulated. IL-1ra was also upregulated in 3 pairs.
Conclusion: We found that PRRT induce systemic cytokine change. Further study is needed to clarify the mechanism of the detected cytokine changes.
- Index Term 1: neuroendocrine tumor
- Index Term 2: peptide receptor radionuclide therapy