Role of intrathecal chemotherapy in the management of meningeal carcinomatosis in patients with breast cancer.

Objective: To evaluate whether intrathecal chemotherapy improves clinical outcomes in patients with meningeal carcinomatosis.

Methods: This retrospective cohort study included consecutive patients with breast cancer diagnosed with meningeal carcinomatosis. Clinical and treatment data were collected from the patients' medical charts. The primary outcome was overall survival, and the secondary outcomes were time to neurological deterioration and reporting of clinical benefit. Logistic regression and Cox proportional hazard models adjusted for potential confounders were used to evaluate the clinical response and overall survival, respectively.

Results: Overall, 109 female patients were included, 50 (45.9%) of whom received intrathecal chemotherapy with methotrexate and dexamethasone. The median treatment duration was 3 weeks (range, 1-13 weeks). Patients treated with intrathecal chemotherapy were more likely to report clinical benefit (74% versus 57.7%, adjusted odds ratio [OR] = 9.0, 95%CI=2.6-30.9, p<0.001). However, there was no difference in the time to neurologic deterioration (hazard ratio [HR] = 0.96, 95%CI= 0.57-1.59, p=0.86). Patients who received intrathecal chemotherapy did not show an increase in overall survival compared with that of patients who did not receive intrathecal chemotherapy (median overall survival = 1.8 months, 95%CI= 1.27-3.0 versus 2.5, 95%CI= 1.9-3.9, adjusted HR = 0.71, 95%CI= 0.41-1.22, p=0.21). There was a significant interaction between intrathecal chemotherapy and systemic treatment, and patients who received systemic therapy without intrathecal chemotherapy had better overall survival than that of the no-treatment group (adjusted HR = 0.38, 95%CI= 0.20-0.70, p=0.002).

Conclusion: Intrathecal chemotherapy did not increase overall survival or time to neurological deterioration and should not preclude or postpone systemic treatments.