Nomogram of myelosuppression and survival prognosis in patients with brain metastases from non-small cell lung adenocarcinoma by intrathecal injection of pemetrexed via the Ommaya Reservoir

Abstract

Abstract Objective: Pemetrexed via Ommaya Reservoir as a new treatment of brain metastases from non-small cell lung adenocarcinoma has been reported in clinical cases. However, there are no studies of the efficacy of pemetrexed via Ommaya Reservoir in patients from the real world. The aim of this study was to explore the efficacy and safety of patients from the real world using pemetrexed via Ommaya Reservoir. Methods: Retrospective analysis of 174 patients with non-small cell lung adenocarcinoma (NSCLA) receiving different treatment of pemetrexed. Nomograms were created based on the independent factors and they were evaluated using consistency index (C-index), AUC, calibration curve and Decision Curve Analysis (DCA) curve. Results: The patients with NSCLA in this study were treated with 4 different treatment regimens using pemetrexed chemotherapy (n=23), intrathecal pemetrexed via Ommaya Reservoir (n=38), co-immunisation (n=65), and co-targeting (n=48). Median progression-free survival (mPFS) was 4.1 months, 8.0 months, 8.0 months and 5.6 months, respectively. Bone metastases (OR=3.011, 95%CI 1.408~6.441), reduced pre-treatment leukocyte (OR=13.036 95%CI5.569~30.517) and Platelet/lymphocyte (PLR) (OR=2.664, 95%CI 1.203~5.903) were associated with the development of myelosuppression; BMI (P=0.008), smoking index >400 (P<0.001), Eastern Cooperative Oncology Group (ECOG) ≥2 (P=0.001), treatment (P=0.001) and systemic immunoinflammatory index (SII) (P<0.001) were associated with PFS. The C-index for the 2 nomograms were 0.845 (95% CI 0.789-0.901) and 0.811 (95% CI0.768-0.854), respectively. Conclusions: Pemetrexed via Ommaya Reservoir is a novel treatment option with good clinical benefit for patients with brain metastases from NSCLA.