Abstract
Gastric cancer is the fifth most common cancer worldwide and leptomeningeal carcinomatosis (LM) occurs in 0.06% of gastric cancers. As such, trials are difficult to power and quantitative analyses difficult to standardize. We composed a review and analysis of 47 recent cases to be used as a comprehensive resource for an oncologist faced with managing this highly morbid, rapidly fatal disease. Gold-standard of diagnosis of LM is through cerebral spinal fluid (CSF) cytology; MRI is the preferred imaging modality to identify LM. However, repeated lumbar punctures and imaging studies are often required to establish diagnosis. Negative results do not rule out LM. Treatment includes radiation and intrathecal chemotherapy, most commonly with methotrexate. Systemic treatment with chemotherapy and immunotherapy is also used. Median survival was 2 months. Intrathecal methotrexate was most commonly dosed at 10-12 mg and treatment continued till symptom resolution, serial lumbar punctures with negative cytology, decrease and stabilization of CSF carcinoembryonic antigen (CEA) levels, progression of disease, or poor functional status. The maximum survival was 12 months. The results of this review indicate that suspicion for leptomeningeal disease should be high in any patient with gastric malignancy or with symptoms consistent with malignancy. Treatment on a biweekly to bi-monthly basis and the addition of systemic therapy to intrathecal therapy should be studied in a matched prospective manner. And in the absence of this information, treatment with at least intrathecal chemotherapy and radiation therapy should be considered in those with a performance status conducive to continued treatment.