Leptomeningeal metastases.

OPINION STATEMENT: Leptomeningeal cancer dissemination is a metastatic complication with growing impact in clinical oncology. Advances in treatment have been hampered by difficulties in diagnosis and response assessment, and nihilistic attitudes of physicians due to the poor prognosis, even when treating patients. However, relevant advances in therapeutic management have been achieved. In selected patients, survival and time to neurological progression can be improved with therapy, although an early diagnosis is critical (hence the importance of a high suspicion index). It is mandatory to perform an MRI of the entire neuraxis and cerebrospinal fluid (CSF) examination of up to two samples if the first lumbar puncture is negative, with appropriate volume and processing methods. It is advisable to supplement CSF analysis using flow cytometry techniques and new biomarker determinations (not yet validated) to improve diagnostic yield sensitivity. Currently, patients with good performance status and the option to receive effective systemic treatment must be treated with added intrathecal chemotherapy through Ommaya reservoirs and focal radiotherapy to bulky lesions or refractory painful areas. However, a standard treatment approach is not well-established due to the lack of well-designed randomized clinical trials and the mix of different cancer subtypes treated with the same drug in most studies. Liposomal cytarabine offers some advantages over methotrexate, both being first-line treatments for intrathecal administration. Recently, new agents have proven safe and feasible, broadening the available treatment options. The individualized choice of intrathecal agent based on the primary malignancy and appropriate treatment of underlying systemic disease are critical to improved outcomes in these patients.