Review of Haematological Toxicities in Well-Differentiated Neuroendocrine Tumours: A Case Report and Comprehensive Review of the Literature.

Background

Neuroendocrine tumours (NETs) are heterogeneous neoplasms with several treatment options. Response rates, disease progression, and haematological toxicities can limit the use of some indicated treatments. Case Presentation: A 73-year-old woman with a well-differentiated grade 2 pancreatic NET (Ki-67 18%) underwent surgical resection and later developed hepatic recurrence. First-line treatment with sunitinib plus octreotide achieved temporary disease stabilisation. Upon progression, peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTATATE was initiated, resulting in stable disease but complicated by grade 3 thrombocytopenia. Two years later, PRRT retreatment was performed due to disease progression, which led to grade 4 thrombocytopenia. Further treatments with capecitabine and everolimus were limited by progression and significant thrombocytopenia. Therapy was switched to streptozocin plus 5-fluorouracil, which resulted in recovery of platelet counts, absence of haematological toxicity, and a sustained radiologic response until March 2025, when she presented with hepatic progression. FOLFOX chemotherapy was initiated but discontinued after one cycle due to severe thrombocytopenia. Deterioration in general condition ultimately led to supportive care and death in March 2026.

Conclusions

This case highlights the risk of cumulative haematological toxicity with PRRT, particularly in retreatment settings. Careful patient selection and close monitoring are essential. Streptozocin-based chemotherapy may be an effective and well-tolerated alternative for patients with treatment-limiting toxicity.