Cytologically proven leptomeningeal carcinomatosis in gastric cancer patients: Experience in a tertiary referral center

Leptomeningeal carcinomatosis (LMC) is a rare but devastating complication of advanced cancer. The reported incidence may be underestimated because of the non-specific clinical presentation and the suboptimal accuracy of the confirmation tests. Despite advances in multidisciplinary care, the prognosis for patients with LMC remains poor. Gastric cancer (GC) ranking 9th in incidence among all kinds of malignancies in Taiwan. We aimed to review our experience with LMC in GC patients at a tertiary referral center to analyze the clinical features and survival outcomes. All patients with a malignant diagnosis of cerebrospinal fluid (CSF) cytology at the National Taiwan University Hospital were reviewed from January 2002 to December 2018. The survival analysis was calculated by the Kaplan-Meier method. Univariate and multivariate Cox proportional hazards regression analysis were used to identify factors associated with survival. We identified 18 patients with a diagnosis of GC-related LMC. LMC occurred in approximately 0.45% of GC patients during this period. Nine (50%) were male, and the median age was 58.5 years old. The most frequent neurological symptom of these patients was altered mental status (72.2%), followed by headache (44.4%) and nausea/vomiting (44.4%). Intracranial hypertension was noted in 87.5% with the mean opening pressure to be 385.3 mmCSF. Intrathecal (IT) chemotherapy was administered to nine patients, principally with methotrexate alone (55.6%). Fourteen patients received CSF drainage by ventriculo-peritoneal shunt or external ventricular drainage via Ommaya reservoir for relieving intracranial hypertension. In the univariate Cox proportional hazards regression analysis, the poor ECOG performance status (>2), absence of other metastases, and absence of CSF drainage were all prognostic factors of poor survival. In conclusion, LMC was a rare manifestation of GC and was associated with an extremely poor survival when the performance status was poor at presentation. CSF drainage may have some impact on the survival duration in selected cases with LMC.