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Peptide receptor radionuclide therapy achieves partial response in rare mixed neuroendocrine tumor

RPEP-135642025Shekhda, Kalyan Mansukhbhai; Luong, Tu Vinh; Krell, Daniel; Navalkissoor, Shaunak; Paterson, Anna; Caplin, Martyn
evidence
The takeaway

A patient with rare mixed neuroendocrine/non-neuroendocrine neoplasm (MiNEN) of pancreato-biliary origin achieved partial response with 4 cycles of 177Lu-DOTATATE PRRT after failing lanreotide, expanding PRRT's potential role beyond pure NETs.

Partial response in MiNEN

First case of PRRT successfully treating a mixed neuroendocrine/adenocarcinoma tumor after lanreotide failure

What the researchers found

MiNEN with 60% grade 2 NET and 30% adenocarcinoma showed no FDG-PET avidity but intense DOTATATE avidity. Failed lanreotide (6 months). Achieved partial response with 4 cycles 177Lu-DOTATATE PRRT with no significant side effects.

Why it matters

MiNENs have no validated treatment guidelines and poor prognosis. This case demonstrates PRRT can be effective when the neuroendocrine component predominates and shows DOTATATE avidity, potentially expanding treatment options for this rare tumor type.

How the study worked

Single case report with imaging (MRI, FDG-PET, 68Ga-DOTATATE PET), histological diagnosis, treatment with lanreotide then PRRT, and response assessment.

What this study cannot tell us

Single case report. MiNENs are highly heterogeneous. Response of adenocarcinoma component unclear. Long-term outcome unknown.

How to read the evidence

Single case report—lowest evidence level but important for an ultra-rare tumor type with no treatment guidelines.

When this study was published

Published in 2025.

The bigger picture

This case pushes the boundaries of PRRT indications beyond pure neuroendocrine tumors into mixed tumors, suggesting that receptor expression rather than pure histology should guide treatment selection.

Questions still open

  • Should all MiNENs undergo DOTATATE-PET to identify PRRT candidates?
  • Does PRRT treat only the NET component or also cross-irradiate the adenocarcinoma?
  • What is the expected duration of response in mixed tumors?

Common questions

What is a MiNEN?
A mixed neuroendocrine and non-neuroendocrine neoplasm (MiNEN) is a rare tumor containing both neuroendocrine cancer cells and another cancer type (usually adenocarcinoma), each making up at least 30% of the tumor. They are hard to treat because they combine features of two different cancer types.
How does PRRT work for these tumors?
PRRT uses a peptide (octreotate) labeled with radioactive lutetium-177 that binds to somatostatin receptors on the neuroendocrine tumor component. This delivers radiation directly to receptor-expressing cancer cells. In this case, the NET component showed strong receptor expression, allowing targeted radiation therapy.

Read the original research

Mixed Neuroendocrine and Non-neuroendocrine Tumor of Pancreato-Biliary Origin Treated Successfully with Peptide Receptor Radionuclide Therapy.

Journal of gastrointestinal cancer, 56(1), 140

View on PubMed ↗Publisher’s paper ↗

Citation

Shekhda, Kalyan Mansukhbhai; Luong, Tu Vinh; Krell, Daniel; Navalkissoor, Shaunak; Paterson, Anna; Caplin, Martyn. (2025). Mixed Neuroendocrine and Non-neuroendocrine Tumor of Pancreato-Biliary Origin Treated Successfully with Peptide Receptor Radionuclide Therapy.. Journal of gastrointestinal cancer, 56(1), 140. https://doi.org/10.1007/s12029-025-01261-5