title: Analysis of SEER Glassy Cell Carcinoma Data: Underuse of Radiotherapy and Predicators of Cause Specific Survival.
abstract: BACKGROUND
  This study used receiver operating characteristic curve to analyze Surveillance, Epidemiology and End Results (SEER) for glassy cell carcinoma data to identify predictive models and potential disparities in outcome.
  
  
  METHODS
  This study analyzed socio-economic, staging and treatment factors. For risk modeling, each factor was fitted by a generalized linear model to predict the cause specific survival. Area under the receiver operating characteristic curves (ROCs) were computed. Similar strata were combined to construct the most parsimonious models. A random sampling algorithm was used to estimate modeling errors. Risk of glassy cell carcinoma death was computed for the predictors for comparison.
  
  
  RESULTS
  There were 79 patients included in this study. The mean follow up time (S.D.) was 37 (32.8) months. Female patients outnumbered males 4:1. The mean (S.D.) age was 54.4 (19.8) years. SEER stage was the most predictive factor of outcome (ROC area of 0.69). The risks of cause specific death were, respectively, 9.4% for localized, 16.7% for regional, 35% for the un-staged/others category, and 60% for distant disease. After optimization, separation between the regional and unstaged/others category was removed with a higher ROC area of 0.72. Several socio-economic factors had small but measurable effects on outcome. Radiotherapy had not been used in 90% of patients with regional disease.
  
  
  CONCLUSIONS
  Optimized SEER stage was predictive and useful in treatment selection. Underuse of radiotherapy may have contributed to poor outcome.
authors.affiliation: Bryn Mawr Ave K43, Bryn Mawr, PA, USA E-mail : cheung.r100@gmail.com.
authors.forename: Rex
authors.initials: R
authors.lastname: Cheung
mesh_terms: D002277:Carcinoma / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D054625:Healthcare Disparities; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D009375:Neoplasms, Glandular and Epithelial / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy*; D012372:ROC Curve; D012306:Risk; D018426:SEER Program; D012959:Socioeconomic Factors