Our study identified a total of 189 patients with histologically-confirmed AT/RT between 2004 and 2016. All patient demographics can be found in Table 1. With a median age at diagnosis of 1 year (interquartile range 0.00 – 4.00), the majority of the cohort was male (105, 55.6%), Caucasian (130, 71%), and lacked Charlson-Deyo comorbidities (157, 83.1%).
The tumor characterization and outcome data of our patient cohort is displayed in Table 2. The average tumor size was 4.75\(\pm\)2.02 cm with 126 (80.8%) patients presenting with a brain mass ≥ 3cm at diagnosis. Sixty-one (34.1%) patients had supratentorial tumors, 51 (28.5%) had infratentorial tumors, 11 (6.15%) had overlapping brain lesions, and 56 (31.3%) had tumors in unspecified locations. Among those under the age of three with specified tumor locations, the largest proportion of patients had infratentorial lesions (35%) compared to those over the age of three, where the majority of patients whose tumor location was specified had supratentorial lesions (50%). Similarly, when dichotomized at the age of one, the largest grouping of younger patients had infratentorial lesions (38%) while in those over the age of one, the most common specified tumor location was supratentorial (40%). Regarding surgical treatment, 97 (53.6%) patients underwent gross total resections, 53 (29.3%) underwent subtotal resections, and 31 (17.1%) underwent biopsy only. Adjuvant treatment consisted of different combinations of chemotherapy, radiation, and bone marrow/stem cell transplant. Overall, 126 (68.1%) patients received chemotherapy, 70 (37.6%) received radiation, and 29 (15.3%) received a bone marrow/stem cell transplant. More specifically, 50 (27.2%) patients underwent surgery only, 51 (27.7%) received surgery with adjuvant chemotherapy, 9 (4.9%) received surgery with adjuvant radiation, 45 (24.5%) received surgery with both adjuvant chemotherapy and radiation. Furthermore, 13 (7.07%) received adjuvant chemotherapy and bone marrow/stem cell transplant while 16 (8.7%) patients received adjuvant chemotherapy, radiation, and a bone marrow/stem cell transplant. Of the 29 patients who received bone marrow/stem cell transplants, the majority (65.5%) were less than 3 years old. More specifically, 6 patients (20.7%) were under 1 year of age when they received a bone marrow/stem cell transplant, 8 patients (27.6%) were 1 year old, 5 patients (17.2%) were 2 years old, 1 patient (3.4%) was 3 years old, 5 patients (17.2%) were 4 years old, 1 patient (3.4%) was 6 years old, 2 patients (6.9%) were 8 years old, and 1 patient (3.4%) was 9 years old. Thirty-nine (20.6%) patients were readmitted within 30 days of surgery; 30- and 90-day survival was 93.5% and 84.4%, respectively.
The median OS for patients with AT/RT tumors was 17.8 months (Figure 1). Univariate Kaplan-Meier analysis demonstrated a significant increase in median survival with increasing age and the administration of chemotherapy, radiation, or bone marrow/stem cell transplant, regardless of regimen (Figure 2). Notably, no association was found between OS extent of resection, or the presence of comorbidities according to Charlson-Deyo classification.
Bivariate analysis of dichotomized age (HR=0.550, 95% CI[0.357, 0.847], p=0.0067) demonstrated significantly increased patient survival if diagnosed with an AT/RT at or above the age of one year, with OS being 7.9 months if under the threshold age and 27.2 months if above the threshold age. Furthermore, those who received the adjuvant chemotherapy and radiation regimen (Hazard Ratio [HR]=0.353, 95% CI[0.201, 0.618], p=0.0003), chemotherapy and bone marrow/stem cell transplant regimen (HR=0.297, CI[0.115, 0.764], p=0.0118), and adjuvant chemotherapy, radiation, and bone marrow/stem cell transplant regimen (HR=0.228, CI[0.088, 0.586], p=0.0022) had significantly prolonged survival compared to patients who only received surgery. Results of all bivariate analyses can be found in Table 3.
Similarly, multivariate analysis demonstrated that OS was significantly increased by adjuvant chemotherapy and radiation regimen (HR=0.377, CI[0.21, 0.68], p=0.0012), chemotherapy and bone marrow/stem cell transplant regimen (HR=0.296, CI[0.11, 0.77], p=0.0109), and adjuvant chemotherapy, radiation, and bone marrow/stem cell transplant regimen (HR=0.272, CI[0.10, 0.74, p=0.0121) when compared to patients who only received surgery. Of note, age did not remain a significant prognostic factor after accounting for treatment regimen. Multivariate modelling of factors impacting OS results are summarized in Table 4.
Further analysis demonstrated that extent of resection, the presence of comorbidities, and treatment type were significantly associated with 30-day mortality, as seen in Table 5. Specifically, gross total resection (HR=13.8, CI[1.69, 112], p=0.0144) and adjuvant chemotherapy (HR=21.1, CI[1.95, 229], p=0.0121) corresponded with an increased 30-day mortality, whereas the presence of comorbidities (HR=0.117, CI[0.018, 0.742], p=0.0229) was associated with decreased 30-day mortality. On multivariate analysis of 90-day survival, only adjuvant chemotherapy (HR=5.16, CI[1.500, 17.8], p=0.0092) was significantly associated with increased survival.