Abstract:

Objective To identify potential prognostic markers of pediatric medulloblastoma (MB) in immunohistochemical results, and to construct a risk stratification system based on the integration of clinical characteristics, so as to guide the postoperative personalized management of MB children. Methods The clinical data of children with MB undergoing resection from January 1, 2011 to August 1, 2020 were retrospectively analyzed, and the logistic regression model was constructed to predict the short-term outcomes (STO) (postoperative tumor residue). The children were divided into high-risk group and low-risk group according to postoperative STO and imaging metastasis characteristics. The COX regression model was used to analyze the independent risk factors for long-term outcome (LTO) including recurrence, reoperation and survival. R software was used to construct the nomogram, and the nomogram was evaluated by C-index, calibration curve and decision curve analysis (DCA). Results A total of 111 children (67 boys and 44 girls) with MB were included, with a median age of 7.0 (4.0-9.0) years. Tumor diameter >5.0 cm (OR=8.07, 95% CI: 2.62-24.89) and MYC protein expression (OR=4.03, 95% CI: 1.29-12.63) can predict STO (AUC=0.81, 95% CI: 0.69-0.92, P<0.001). The 12-month LTO-free survival (LOFS) of the high-risk group (n=50) was 76.0% (95% CI: 70.0%-82.0%), and that of the low-risk group (n=61) was 83.6% (95% CI: 78.9% -88.3%). The difference between the two groups was statistically significant (HR=2.77, 95% CI: 1.53-5.01). COX regression model showed that risk grouping, age≤3 years, diameter>5.0 cm, and MYC positive were independent risk factors for poor LTO (P<0.05). Based on the above clinical-biological independent risk factors, LOFS can be accurately predicted by establishing a nomogram, with a C-index of 0.715. Moreover, the calibration curve showed a high degree of consistency between the predicted risk and the actual risk. The net benefit was good in DCA for a wide range of prediction probabilities, demonstrating a good clinical utility. Conclusions The nomogram constructed based on risk grouping, age, tumor diameter and MYC are conducive to the targeted monitoring and management of pediatric MB.

Key words: medulloblastoma, prognosis, nomogram