Triple intrathecal chemotherapy for leptomeningeal carcinomatosis in solid tumors: Treatment outcomes, response and their determinants.

Background Leptomeningeal carcinomatosis (LC) is the metastatic infiltration of leptomeninges by malignant cells originating from an extrameningeal primary tumor site, either extraneural or intraneural. In the absence of treatment, survival is usually measured in weeks, however with treatment this may be extended to a few months. Our institutional protocol has been to offer intrathecal chemotherapy (ITC) to patients having solid tumors with cerebrospinal fluid (CSF) cytology positive leptomeningeal carcinomatosis. This study was performed to describe the oncological outcomes in this cohort and their determinants. Methods A retrospective review of data of patients treated at Amrita Institute of Medical Sciences, Kochi, India was performed. Patients with CSF cytology positive solid tumors treated with triple ITC (methotrexate, cytosine arabinoside and hydrocortisone) were assessed for patient characteristics, treatment response, survival and the factors affecting them. Results Twenty patients of LC treated with triple ITC were included in the study. The median age of the study group was 49 years with a slight female preponderance (55%). All patients had positive CSF cytology with mean CSF glucose of 60 mg/dL, mean CSF protein of 92 mg/dL and mean cell count of 5. Breast cancer was the most common primary tumor (45%), followed by lung (35%) and stomach (5%). Symptomatic improvement was reported in 70% of patients after initiating ITC. Median overall survival (OS) at 6 and 12 months was 38% and 14%, respectively. Median progression-free survival (PFS) was 2 months. Patients with brain parenchymal metastasis had poor 6 month OS (25% vs 50%, P = 0.013) and 6 month PFS (0% vs 20%, P = 0.023). Conclusion A triple drug combination of methotrexate, cytosine arabinoside and hydrocortisone when given intrathecally for patients with LC showed good control of symptoms and reasonable survival. It may be beneficial in patients with no brain parenchymal involvement.