A Clinical Study of Furmonertinib in the Treatment of EGFR-Mutated NSCLC With Leptomeningeal Metastases

Inclusion criteria

• Patients aged ≥18 years, male or female;
• Histologically or cytologically confirmed diagnosis of **non-small cell lung cancer (NSCLC);
• " EGFR mutation-positive"(classic or non-classic mutations) confirmed by genetic testing;
• "Leptomeningeal metastasis" definitively diagnosed by investigators based on "EANO-ESMO diagnostic criteria", involving comprehensive clinical assessment including symptom evaluation, imaging evaluation (MRI/CT), and/or cerebrospinal fluid (CSF) cytology;
• Received furmonertinib (treatment duration ≥1 month) between "March 3, 2021, and December 31, 2024", with concurrent therapies permitted (e.g., radiotherapy, intrathecal chemotherapy, surgical interventions such as ventriculoperitoneal shunting).

Exclusion criteria

• History of other malignancies during NSCLC treatment or prior to diagnosis, except those effectively controlled (e.g., complete remission ≥5 years);
• Severe gastrointestinal disorders affecting drug administration or absorption, including but not limited to peptic ulcer disease, inflammatory bowel disease, or malabsorption syndromes;
• Evidence of uncontrolled systemic diseases (e.g., uncontrolled hypertension [BP >140/90 mmHg despite treatment], diabetes mellitus [HbA1c >8%], arrhythmias, heart failure [NYHA class III/IV], active bleeding, active infections requiring IV antibiotics, or interstitial pneumonia requiring corticosteroid therapy), which in the investigator's judgment may directly compromise patient prognosis;
• Incomplete medical records or follow-up data;
• Pregnancy or lactation;
• Other severe acute/chronic medical conditions, psychiatric disorders, or laboratory abnormalities that, in the investigator's opinion, may confound the interpretation of study results.