As of January 2023, the UCSF IRB now requires that screening biopsies be the last screening procedure conducted, whenever possible. This will avoid any unnecessary procedure that is accompanied by risks, if the patient will be later deemed ineligible based on simpler screening interventions, such as lab blood values.

Study teams should: 

1. Use archival sample whenever possible 

2. If archival sample is not available, look first at other non-invasive exclusion criteria   

3. Screening biopsy consent should be part of the main ICF (so potential participants are aware of the risks of the main study in the event they are determined eligible) 

4. A biopsy performed during screening that is not done for eligibility purposes cannot be mandatory. It can be optional.