Re. Pre-diagnostic exposures and cancer survival: Can a meaningful causal estimand be specified?

(1) Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles (UCLA), Los Angeles, CA, United States. (2) Practical Causal Inference Lab, UCLA, Los Angeles, CA, United States (3) Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, PA, United States. (4) Department of Statistics and Data Science, Division of Physical Sciences, College of Letters and Science, UCLA, Los Angeles, CA, United States. (5) Department of Public Health, Research Unit for Epidemiology, Aarhus University, Aarhus, Denmark. Funding statement: MMC was supported by the National Cancer Institute, grant number NIH/NCI T32 CA009142. Work on this project was also supported in part by the UCLA Jonsson Comprehensive Cancer Center's Office of Cancer Training and Education. Conflicts of interest: None Corresponding Author: Matthew M Coates, Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles (UCLA), Los Angeles, California, USA, [email protected]