SAT-122 Expression of Cell Synthesis and Dna Repair Markers in Meningioma Recurrence or Regrowth

Meningiomas correspond to 37% of intracranial tumors and are considered the second most common neoplasm of the central nervous system in adults. Most of them are benign with slow growth pattern, common from the fifth decade, more frequent in women and with high recurrence rates. In tumors, there is a reduction in the efficiency of DNA error repair, allowing the proliferation of tumor cells. In this work, we evaluated the protein expression of markers involved in cell synthesis (cyclin D1) and repair of DNA errors (MUTYH, XPF, and XPG) in meningiomas. To date, this is the first study to use the immunohistochemical technique in the evaluation of these repair proteins, relating them to clinical data, tumor variables and recurrence-regrowth free survival. 85 samples were included in the study, patients with a mean age of 52 + 13.3 years, 68% female, in proportion 2:1. Most cases were classified as grade I (79%), meningothelial subtype (38%) and transitional (25%). Regarding surgery, 59% of the patients underwent total resection. Regarding location, the most common was the peripheral (62.2%). Most tumors (64%) were larger than 3cm, with a mean of 3.6±2cm. The median recurrence-regrowth free survival was 67 months (95% CI:57.8-76.6). According to the Kaplan-Meier curve, the recurrence-regrowth free survival rate was 94.4% at 1 year, 76.6% at 2 years and 64.7% at 3 years and 49.4% at 5 years. Grades II and III were prognostic factors for tumor recurrence-regrowth (p<0.05). Cyclin D1 was positive in 92%, 77% in grade I and 23% in grades II and III. A statistically significant relationship was found between cyclin D1 and tumor grade (p = 0.001), with higher expression in grade II and III. Repair proteins were expressed in most meningiomas. MUTYH (63.5%), 43.5% in grades I and 20% in grades II and III, with a significant relationship between grades II and III and, expression 10-50% (p=0.02). Significant association was observed with MUTYH (p=0.001) and XPF (p=0.019). XPF and XPG were associated with grades II and III (p=0.002 and p<0.001) and XPF with size >3cm (p=0.03). There was a positive correlation between XPF and XPG (p= 0.02) and between MUTYH and XPF (p=0.003). XP proteins were related to recurrence-regrowth (p=0.04), but not with recurrence-regrowth free survival. Our results demonstrate the activation of repair pathways and increased cell synthesis in grades II and III in meningiomas. Cellular synthesis and DNA repair markers are important tools to broaden knowledge about the biological behavior of meningiomas.