a) Difference between FaceAge and age across cancer types and datasets to investigate if individuals look older or younger compared to their age. Analyzing all cancer patients included in our analysis, we found that, on average, cancer patients look older than their age. This difference was significant when comparing these results to the reference UTK dataset of healthy individuals 60 years and older. b) Difference between FaceAge and age for current, former, and never smokers included in the MAASTRO cohort. c) Scatterplot assessing the association of FaceAge with body mass index (BMI) in the MAASTRO cohort. d) Association of FaceAge with performance status (Eastern Cooperative Oncology Group (ECOG)) was quantified for a subset of patients in the MAASTRO cohort. In the boxplots the box covers the interquartile range (IQR), with the line at the center of the box indicating the mean; the top (bottom) whisker extends from the box to the largest (smallest) value within 1.5 IQR (***: p<0.001; unpaired, two-sided t-test was used in all cases).