Fig. 4

Regression Analysis of Calcitonin and Carcinoembryonic Antigen Levels by Line of Treatment^a. A. Calcitonin Levels During First-Line Treatment. B. Carcinoembryonic Antigen Levels During First-Line Treatment. CEA carcinoembryonic antigen. C. Calcitonin Levels During Second-Line Treatment. CEA carcinoembryonic antigen. Note: A locally weighted polynomial regression, or LOESS, fit was estimated to smooth the data points and highlight the underlying trend [18]. ^aPredicted using an unadjusted, mixed-model repeated-measures analysis. ^bEvaluations 28 days before or after initiating treatment line were attributed to baseline (i.e., time 0). Evaluation after 28 days of treatment initiation were grouped in to 28-day intervals and have been assigned to the end of the interval