Molecular and clinical prognostic factors for favorable outcome following surgical resection of adult intramedullary spinal cord astrocytomas

Objective Intramedullary spinal cord astrocytomas are uncommon but important entities. Aggressive surgical resection is believed to be critical to prevent subsequent neurological deterioration; however, the prognostic significance of numerous patient and molecular variables remains unclear. We sought to investigate the clinical and molecular factors associated with outcomes following surgical resection of adult spinal cord astrocytomas. Methods A consecutive retrospective chart review of all patients who underwent intramedullary spinal cord astrocytoma resection at a single tertiary-care institution between January 1996 and December 2011 was conducted. Molecular data collected included p53 mutation status, proliferative activity (Ki-67), 1p/19q chromosome loss, and EGFR amplification. Multivariable logistic and Cox proportional hazards regression were used to identify variable associated with postoperative outcomes. Results Among 13 patients undergoing surgical resection followed for a median of 54 months, 54% experienced improvement in neurological status, while 15% remained unchanged and 31% deteriorated. Following resection, the 5-year local control (LC), progression-free survival (PFS), and overall survival (OS) rates were 83%, 63%, and 83%. Median PFS time was found to be 5.6 years. Multivariable regression revealed limited characteristics associated with postoperative outcomes, though no molecular characteristics were found to be prognostic. Older age at surgery predicted decreased probability of PFS (HR 0.91, 95% CI 0.81-0.99, p = 0.03) and trended towards predicting lack of neurological improvement (OR 0.94, 95% CI 0.83-1.02, p = 0.21) and decreased OS (HR 0.93, 95% CI 0.81, 1.03, p = 0.15). Preoperative motor symptoms (OR 0.12, 95% CI <0.01-1.91, p = 0.14) and adjuvant chemotherapy (OR 0.07, 95% CI <0.01-1.82, p = 0.12) also trended towards predicting lack of neurological improvement. Conclusion Age was the only patient variable found to have a statistically significant association with profession-free survival and no other factors were significantly associated with postoperative outcomes. These findings were limited by a relatively small sample size; thus, future studies with increased power investigating the prognostic effects of molecular characteristics could provide further clarity in identifying patients most likely to benefit from surgical resection.