Hematological Markers as Predictors of Treatment Outcomes with Lutetium 177 (177Lu)-DOTATATE in Patients with Advanced Neuroendocrine Tumors.

Background: Chronic inflammation has been linked to the development and prognosis of neuroendocrine tumors (NETs). The current study intended to evaluate the role of peripheral hematological inflammatory markers, viz. the platelet-lymphocyte ratio (PLR), neutrophil-lymphocyte ratio, and monocyte-lymphocyte ratio, as predictors of treatment outcomes in patients with advanced NETs after Lu-177 DOTATATE therapy. Materials and Methods: Data of consecutive patients with advanced metastatic and/or inoperable NETs treated with Lu-177 DOTATATE from the year 2012 to 2019 at the authors' center were retrospectively analyzed. Results: Forty-two NET patients (median age: 49.5 years) received a median cumulative activity of 29.6 GBq of Lu-177 DOTATATE over 2-5 cycles at 8-12-week intervals. The median progression-free survival (PFS) of the study cohort was 30 months (95% confidence interval, CI: 18.2-41.9 months). A baseline PLR ≥173.1 was found to be a significant predictor of poor PFS with a univariate hazard ratio of 3.82 (95% CI: 1.21-12.03); however, the association was not significant on multivariate analysis. The median overall survival was not reached and none of the parameters were significantly associated with it. Conclusions: A higher baseline PLR was shown to be associated with a negative outcome on PFS after 177Lu-DOTATATE therapy and is a promising marker for future larger studies.