Radiographic appearance of leptomeningeal disease in patients with EGFR-mutated non-small-cell lung carcinoma treated with tyrosine kinase inhibitors: a case series

Osimertinib is associated with improved outcomes in pre-treated non-small cell lung cancer leptomeningeal metastases: A systematic review and meta-analysiss

Purpose

Leptomeningeal metastasis (LM) is a severe complication of non-small cell lung cancer (NSCLC). In patients with NSCLC LM harboring epidermal growth factor receptor (EGFR) mutations, osimertinib is favored over alternative EGFR tyrosine kinase inhibitors (TKIs). However, the efficacy of osimertinib relative to other EGFR-TKIs is not well established for patients with LM. We aimed to compare the efficacy of EGFR-TKIs in EGFR-mutated NSCLC LM.

Methods

This systematic review and meta-analysis performed according to PRISMA guidelines included studies of adult patients with EGFR-mutated NSCLC and a diagnosis of LM who received an EGFR-TKI for the treatment of LM. We searched Medline ALL, Embase, Cochrane Central Register of Controlled Trials, Scopus, and Web of Science Core Collection. The evaluation of biases was done by using the Ottawa-Newscastle scale. The hazard ratio was used as the parameter of interest for overall survival (OS) and central nervous system-specific progression-free survival (PFS).

Results

128 publications were included with 243 patients and 282 lines of EGFR-TKI for NSCLC LM that met inclusion criteria. The median PFS in patients receiving any EGFR-TKI was 9.1 months, and the median OS was 14.5 months. In univariate analyses of the entire cohort, osimertinib treatment demonstrated significantly prolonged PFS, but not OS, compared to other EGFR-TKIs. Osimertinib demonstrated significantly prolonged PFS and OS in the subset of patients who were previously treated with EGFR-TKIs, but not in EGFR-TKI naïve patients.

Conclusion

Osimertinib is associated with improved outcomes compared to other EGFR-TKIs, particularly in patients previously treated with EGFR-TKIs. An important limitation is that most patients were derived from retrospective reports. These results highlight the need for prospective studies for this difficult-to-treat patient population.

Case Report: Focal leptomeningeal disease, atypical cancer of unknown primary site

Background: Leptomeningeal metastasis is an infrequent form of cancer expression, and it has a poor prognosis due to its torpid evolution and its challenging diagnosis. Case report: We report the case of a 68-year-old woman with rapidly progressing cognitive decline and focal epilepsy. Brain magnetic resonance imaging showed extensive gyriform hypersignal in the right precentral sulcus region, without mass effect, tenuous contrast uptake, and hydrocephalus with transependymal edema. The body tomographic study was negative for solid cancer and the 18F-FDG PET-CT revealed a severe hypermetabolism in the right lung upper lobe. These findings were suggestive of lung cancer with leptomeningeal metastasis. We performed a brain biopsy, finding atypical cells in the leptomeningeal region with positive immunohistochemical staining for CK7 and negative for CK20 corresponding to lung adenocarcinoma. The patient was evaluated in the oncology service and scheduled for radiotherapy and chemotherapy. Conclusions: Focal leptomeningeal disease is an entity that should be considered as a differential diagnosis in all cases of focal leptomeningitis. Timely diagnosis and adequate cancer management can increase patient survival.

Focal Leptomeningeal Disease with Perivascular Invasion in EGFR-Mutant Non-Small-Cell Lung Cancer

We report a previously undescribed pattern of brain metastases in patients with epidermal growth factor receptor-mutated non-small-cell lung cancer treated with tyrosine kinase inhibitors and radiation therapy. These highly distinct lesions appear to spread focally within the leptomeninges, with invasion along the perivascular spaces (FLIP). The survival of patients with FLIP was significantly better compared with patients with classic leptomeningeal disease (median survival, 21 versus 3 months; P = .003). It is unclear whether this pattern of growth is unique to epidermal growth factor receptor-mutated non-small-cell lung cancer.