Blakaj, Dukagjin

Abstract Background:The standard of care for elderly glioblastoma (GBM) patients is 40 Gy in 15 fraction radiotherapy with temozolomide (TMZ). However, this regimen has a lower biologic equivalent dose (BED) compared to the Stupp regimen of 60 Gy in 30 fractions. We hypothesize that accelerated hypofractionated radiation of 52.5 Gy in 15 fractions (BED equivalent to Stupp) will have superior survival compared to 40 Gy in 15 fractions.Methods:Elderly patients (≥ 65 years old) who received hypofractionated radiation with TMZ from 2010-2020 were included in this analysis. Overall survival (OS) and progression free survival (PFS) were defined as the time elapsed between surgery/biopsy and death from any cause or progression. Baseline characteristics were compared between patients who received 40 Gy and 52.5 Gy. Univariable and multivariable analyses were performed.Results: Sixty-six newly diagnosed patients were eligible for analysis. Thirty-nine patients were treated with 40 Gy in 15 fractions while twenty-seven were treated with 52.5 Gy in 15 fractions. Patients had no significant differences in age, sex, methylation status, or performance status. Overall survival (OS) was superior in the 52.5 Gy group (14.1 months) when compared to the 40 Gy group (7.9 months, p = 0.011). Isoeffective dosing to 52.5 Gy was shown to be an independent prognostic factor for improved OS on multivariable analysis. Conclusions:Isoeffective dosing to 52.5 Gy in 15 fractions was associated with superior OS compared to standard of care 40 Gy in 15 fractions. These hypothesis generating data support accelerated hypofractionation in future prospective trials.

10016 Background: The impact of race and socioeconomic status (SES) on cancer mortality has been elucidated in adult patients, but is not well described in pediatric oncology. We hypothesize that racial and socioeconomic disparities exist in pediatric cancer patients, resulting in higher rates of hospitalization and mortality. Methods: We analyzed the Kids’ Inpatient Database (KID) which shows national estimates of inpatient stays for pediatric patients. Inclusion criteria included patients who were ≤20 with a cancer diagnosis identified through the Clinical Classifications Software (CCS). Variables analyzed were discharge status, patient demographics, hospital characteristics, expected payment source, total visit charge, and length of stay. Initial comparisons between cancer and non-cancer related discharges were performed using a chi-square test. To estimate disparities by race, clinical comparisons were performed across five racial groups: White, Black, Hispanic, Asian/Pacific Islander, and Native American/Other. A multivariable logistic regression model was used to examine predictors of hospitalization and mortality. Results: From 2006-2012, there were 9,488,477 non-cancer related pediatric inpatient stays and 242,489 cancer related stays. Patients with cancer related visits were more likely to be white, male (54.9% vs 46.1%, p < 0.0001), older at admission, have private insurance (52.5% vs 41.7%), and were from a higher income quartile (76th-100th percentile, 25.2% vs 19.9%, p < 0.001). These patients also had a higher rate of death during admission (1.2% vs 0.5%, p < 0.0001), higher cost of visit charge ($25,097 vs $8,267, p < 0.001), longer length of stay (4 vs 2 days), and were less likely to be discharged (85.5% vs 92.0%, p < 0.0001).The four most frequent cancer diagnoses associated with hospital admission were leukemia (n = 75,807), Other and Unspecified Primary (n = 50,076), bone/connective tissue tumor (n = 42,477), and central nervous system tumor (n = 27,958). Patients who were non-white were more likely to die during their inpatient stay (1.5% Non-white versus 0.9% White, p < 0.001). On multivariate logistic regression, Black (OR: 1.61, 95% CI: 1.57-1.66, p < 0.0001) and Native American (OR: 1.39, 95% CI: 1.34-1.44, p < 0.0001) race, as well as lower income quartile (OR: 1.24, 95% CI: 1.19-1.28, p < 0.001) were associated with increased odds of death during admission. Conclusions: This is the largest observational study to date to identify the impact of race and SES on pediatric cancer hospitalization and mortality in the United States. Non-white race and lower SES was associated with significantly increased odds of death during admission. Given the significant difference in mortality by race, healthcare policy makers and insurance companies should investigate the specific drivers of increased admission and mortality and develop strategies to address inequity in cancer care.