Leptomeningeal Carcinomatosis in Colorectal Cancer: The Mayo Clinic Experience.

BACKGROUND: Leptomeningeal metastasis (LM) is an uncommon form of metastatic disease in many cancers. There remains a paucity of literature with regard to the course and management of LM in colorectal cancers (CRCs). The aim of this study was to estimate the incidence of LM in patients with CRC seen at our institution over a 15-year period, and to describe the clinical course and outcome of these cases.

METHODS: LM in CRC primary cases between 2000 and 2014 were identified in the Mayo Clinic databases. The charts were retrospectively reviewed.

RESULTS: Of 17,095 CRC primaries, we identified 10 patients with LM (0.058%) in this 15-year period. Nine cases were included in the analysis. Four had metastatic disease at the time of their initial CRC diagnosis. Median overall survival after CRC diagnosis was 25.7 months (range, 4.7-74.8 months). Median time to diagnosis of LM after CRC diagnosis was 25.3 months (range, 0-68.1 months). All patients had magnetic resonance imaging findings consistent with LM: 3 patients with spinal LM, 5 patients with intracranial LM, and 1 with both. Neurologic symptoms correlated with site of the lesions, with headache, cranial nerve palsy, lower extremity weakness, and gait disturbance among the most frequently reported. However, not all patients had neurologic findings, with LM lesions found incidentally in 2 cases. Seven patients (78%) had palliative radiotherapy for LM. Three patients continued to receive systemic chemotherapy after diagnosis of LM. Median survival after LM diagnosis was 7 weeks (range, 2-39 weeks).

CONCLUSIONS: LM is an exceedingly rare development in the natural course of CRC. It confers a poor prognosis with limited treatment options. At our institution, most patients had their disease addressed by palliative means, with many receiving radiotherapy to control their neurologic symptoms. Based on our series, supportive care remains a sensible approach to the management of LM in CRC.