Dose-Limiting Bone Marrow Toxicities After Peptide Receptor Radionuclide Therapy Are More Prevalent in Women Than in Men.

Purpose: Peptide receptor radionuclide therapy (PRRT) can cause dose-limiting toxicities (DLTs) of the bone marrow, liver, and kidneys. It is yet unknown whether women and men are equally at risk of these DLTs.

Methods: Neuroendocrine tumor patients treated with 177Lu-DOTATATE between 2000 and 2015 in our phase II trial with available laboratory data were included. For all DLTs, the highest Common Terminology Criteria for Adverse Events (version 4.03) grades that occurred from the start of PRRT until 3 months after the last cycle were scored.

Results: At baseline, women (n = 439) had a significantly lower body mass index, Karnofsky Performance Score, hemoglobin level, and creatinine clearance and a significantly higher platelet level than men (n = 534). Both groups received a median activity of 29.6 GBq (800 mCi). After the start of PRRT, women more frequently developed grade ≥2 thrombocytopenia compared with men (25% vs 18%, P = 0.004) due to a significant increase in grade ≥3 thrombocytopenia (11% vs 6%, P = 0.008). Furthermore, the incidence of grade ≥3 anemia was higher in women (7% vs 3%, P = 0.002). In the multivariable regression model, female sex (odds ratio, 2.50; 95% confidence interval, 1.67-3.74) was confirmed to be an independent risk factor for grade ≥2 thrombocytopenia, among baseline platelet count, bone metastases, uptake on 111In-DTPA-octreotide scan, Karnofsky Performance Score, alkaline phosphatase, lymphocytes, albumin, and renal function.

Conclusions: Female neuroendocrine tumor patients more often experienced PRRT-induced toxicities of platelets and hemoglobin than males, but this did not lead to a lower cumulative activity.