Prognostic factors and clinical outcomes in patients with leptomeningeal metastasis from solid tumors

Background Leptomeningeal metastasis (LM) occurs in 4–15% of patients with solid tumors. Although the clinical outcomes in cancer patients have been improving recently, no standard treatment for LM has been established as yet. The purpose of this study was to identify the prognostic factors in patients with solid tumors with cytologically proven LM. Methods We retrospectively analyzed a series of 85 consecutive patients with cytologically proven LM who were treated between 1997 and 2005. Results The primary diseases were as follows; lung cancer (n = 36), breast cancer (n = 33), gastric cancer (n = 8), and others (n = 8). Forty-nine patients had brain metastasis at the time of diagnosis of the LM, and in 51 patients, MRI revealed meningeal dissemination in the brain or spine. The performance status (PS) was 0–1 in 26 patients and 2–4 in 59 patients. Thirty-one patients, including 19 with breast cancer, four with lung cancer, five with gastric cancer and three with other cancers, were treated by intrathecal (IT) chemotherapy. The response rate to the IT was 52% (95% confidence interval (CI): 41.4–62.6%). The median survival was 51 days (range, 3–759 days). A univariate analysis identified breast cancer, good PS (0–1), time to development of the LM (>1 year), and treatment by IT chemotherapy as being associated with a good prognosis, and multivariate analysis identified poor PS (HR: 1.72 (95% CI, 1.04–2.86) P = 0.04) and MRI-proven LM (HR: 1.82 (95% CI, 1.11–2.98) P = 0.02) as being associated with a poor prognosis. Conclusion In patients with poor prognostic factors, such as poor PS or MRI-proven LM, palliative therapy might be the most suitable treatment strategy.