Abstract 527P
Background
Leptomeningeal metastases (LM) of lung cancer represent a severe neurological complication with a poor prognosis and limited effective treatments. Although intraventricular chemotherapy (IVC) is the preferred management for LM, there is currently insufficient data to support its effectiveness.
Methods
We conducted a retrospective study that analyzed data from consecutive patients with LM from lung adenocarcinoma who underwent Ommaya reservoir insertion at the Nanjing Chest Hospital between 2020 and 2022. The diagnosis of LM was based on either cerebrospinal fluid (CSF) cytology or concordant clinical and neuroimaging findings. The chemotherapy regimen consisted of pemetrexed (30mg or 50mg) and dexamethasone (5mg) administered twice a week for up to 2 weeks during the induction phase, followed by a maintenance phase once a month until progression or maximal doses were reached.
Results
We retrospectively analyzed 56 patients (median age, 56 years) with driver gene mutations, including 46 patients with EGFR mutations, 2 patients with other gene mutations, and 8 patients with non-driver genes. Of the patients, 48.3% had an ECOG PS of 4, 35.7% had an ECOG PS of 3, and 16% had an ECOG PS of 2. Additionally, 41 patients (73.2%) received a 30mg dose of pemetrexed, and 15 patients (26.8%) received a 50mg dose. In all patients, 31 had a response, 19 had stable disease (SD), and 6 had disease progression (PD), resulting in an overall response rate (ORR) of 55.4% and a disease control rate (DCR) of 89.3%. The median progression-free survival (mPFS) was 6.8 months, and the median overall survival (mOS) was not reached. Subgroup analysis showed that the mPFS for the pemetrexed 50mg and 30mg groups was 12 months and 6.8 months, respectively (p=0.006), and the mPFS was 9.6 months versus 4 months in the ECOG PS of 2-3 and 4 arms(Fig1B), respectively (p=0.001). The overall adverse event (AE) rate was 65%, with all adverse effects, including nausea, vomiting, seizures, and myelosuppression, being mild and transient.
Conclusions
In this real-world study, IVC with pemetrexed demonstrated excellent and encouraging results in patients with lung adenocarcinoma and LM, at an acceptable cost of toxicity.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
122P - Distinct transcriptomic immune profiling and clinicopathological features of cribriform morphology in colorectal adenocarcinomas
Presenter: Abdelhakim Khellaf
Session: Poster Display
Resources:
Abstract
123P - Spatial molecular profiling identifies FGF20 upregulation on cancer-associated fibroblast and FGFR2-PI3K/Akt activation in tumor cells of sporadic early-onset colon cancer
Presenter: Dave Hoon
Session: Poster Display
Resources:
Abstract
124P - Characteristics, prognosis and therapeutic effects of non-V600 BRAF mutated colorectal cancer
Presenter: Lalida Arsa
Session: Poster Display
Resources:
Abstract
125P - Final results of APOLLON-11 and SOYUZ-APOLLON study: Multicentre prospective observational post-authorization study of bevacizumab biosimilar in patients with metastatic colorectal cancer in real-world practice
Presenter: Alexey Tryakin
Session: Poster Display
Resources:
Abstract
126P - From tumor height (TH) to tumor regression grade (TRG) in locally advanced rectal cancers (LARC) during total neadjuvant therapy (TNT): A retrospective analysis
Presenter: Valeria Pusceddu
Session: Poster Display
Resources:
Abstract
127P - A meta-analysis of efficacy and safety from head-to-head first-line (1L) trials of epidermal growth factor receptor inhibitors (EGFRIs) versus bevacizumab in combination with chemotherapy (CT) doublets in patients with RAS wild-type (WT) metastatic colorectal cancer (mCRC) by sidedness
Presenter: Takayuki Yoshino
Session: Poster Display
Resources:
Abstract
128TiP - A phase II study of cadonilimab + FOLFOXIRI and bevacizumab as initial therapy for unresectable proficient mismatch repair/microsatellite stable (pMMR/MSS) metastatic colorectal cancer (mCRC)
Presenter: Rongbo Lin
Session: Poster Display
Resources:
Abstract
140P - Prevalence of claudin-18 isoform 2 (CLDN18.2) positivity in locally advanced (LA) unresectable or metastatic gastric or gastroesophageal junction (mg/GEJ) adenocarcinoma in patients (pts) in the Asia region: Phase III SPOTLIGHT and GLOW studies
Presenter: Hoo Hwoei Fen Soo
Session: Poster Display
Resources:
Abstract
141P - Early phase trials outcomes in refractory upper GI cancers: A 10-year analysis from the SCRI UK phase I unit
Presenter: Antonella Cammarota
Session: Poster Display
Resources:
Abstract
142P - The survival impact of the addition of durvalumab to cisplatin/gemcitabine in advanced biliary tract cancer: A real-world, retrospective, multicentric study
Presenter: Silvia Foti
Session: Poster Display
Resources:
Abstract