- Inclusion of pemetrexed in chemotherapy regimens is associated with longer survival in patients with epidermal growth factor receptor (EGFR)-positive NSCLC and leptomeningeal metastasis (LM).
Why this matters
- Studies suggest a higher incidence of LM in EGFR-mutant vs wild-type disease.
- 631 patients with advanced EGFR+ NSCLC.
- Funding: Ministry of Health & Welfare, Republic of Korea.
- 17.4% developed LM.
- Among LM group, 58.2% were women, 62.6% were never-smokers, and 94.5% had adenocarcinoma.
- Median time from lung cancer diagnosis to LM onset was 14.4 months.
- LM was present at lung cancer diagnosis in 14.5% of patients.
- 51.8% of patients with LM were treated with systemic chemotherapy after LM diagnosis.
- Of these, 17.3% received pemetrexed and 40% EGFR TKIs.
- Median OS after LM was significantly longer in patients who received pemetrexed after LM diagnosis than those who did not (13.7 vs 4.0 months; P=.008), and in those who used TKIs after LM diagnosis (16.9 vs 3.0 months; P<.001>
- Use of pemetrexed (HR, 3.1; P=.002) and TKIs (HR, 3.0; P=.001) after LM diagnosis predicted better post-LM OS.
- Retrospective study.