Anaplastic Thyroid Cancer (Atc): Prognostic Factors, Patterns Of Care, And Overall Survival

ATC represents a rare yet highly aggressive malignancy. We sought to analyze factors predictive for overall survival and use of high-dose radiation therapy (HDRT) as well as patterns of care for patients with ATC in a population-based cohort. In doing so, we aim to add to the body of knowledge regarding patient selection for aggressive treatment versus supportive care. Using the National Cancer Data Base from 1999 to 2012, we identified 3552 patients with ATC. Factors associated with use of HDRT (≥59.4 Gy) were evaluated using a parsimonious multivariate logistic regression model. From this, a propensity score for receipt of high-dose RT was generated and incorporated into a multivariate Cox regression analysis for overall survival. Three-month conditional landmark analysis was performed. Median overall survival was 3.5 months (inerquartile range [IQR], 1.5-8.8). RT use was 59.2% overall and 72.7% for patients who lived more than 3 months, while for chemotherapy (CT) the rates were 42.4% and 56.5%, respectively. Both RT and CT were given to 37.3% of patients (75.0% concurrent). Median time from diagnosis to RT initiation was 27 days (IQR, 13-46) and 30 days for CT (IQR, 15-47). RT lasted a median of 35 days (IQR, 17-48). Death within 30 days of starting RT occurred in 18.2% of patients and within 60 days for 35%. Median RT dose was 45 Gy (≤36 Gy = 32.1%, ≥59.4 Gy = 38.1%). Factors predictive for HDRT use were later year of diagnosis, private insurance, rural residential setting, higher residential area median income, no reported metastasis, negative surgical margins, receipt of surgery, and receipt of chemotherapy. Factors associated with improved overall survival were age <65 years, lower Charlson-Deyo comorbidity score, treatment at a community/comprehensive community hospital, facility volume >5 cases, primary confined to the thyroid, total thyroidectomy, other surgery, RT, and CT (hazard ratios [HR]=0.71, 0.74, 0.82, 0.79, 0.71, 0.35, 0.48, 0.59, and 0.69, respectively, all P6 cm, and positive surgical margins (HR=1.22, 1.82, 1.38, and 1.53, respectively, all P