# Drop mandatory fresh biopsies where blood or archival tissue would do

Source: https://onco.cc/ideas/idea-tr1-drop-non-essential-biopsies/  
OnCo record `idea-tr1-drop-non-essential-biopsies` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Trials often require a fresh tumour biopsy just to enter, even when the sample is only for research. Classifying each biopsy as essential or research-only, making the latter optional and allowing blood tests or archived tissue for eligibility markers, would remove a painful hurdle that drives refusals.

## Summary

Protocols classify each biopsy as essential (eligibility-defining, no alternative) or research-only; research-only biopsies become optional sub-studies, and eligibility biomarkers may be assessed on archival tissue or ctDNA where analytically validated. Screen-failure and refusal attributable to biopsy requirements are tracked and published.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: Removing mandatory research biopsies will reduce screen failure and refusal rates by a measurable margin and shorten time to enrolment, without loss of the biomarker data needed for the primary analysis.
- Rationale: Mandatory biopsies are among the most frequently cited reasons patients decline early-phase trials, and a notable share of biopsies yield insufficient tissue. Liquid biopsy now matches tissue for many actionable alterations.
- Proposed test: A sponsor amends a set of ongoing trials to make research biopsies optional and compares screen failure, refusal and enrolment speed before and after amendment.
- Maturity: early-clinical
- Actor: industry

## Sources

- Bottleneck evidence (Trials enrol too few, too slowly): Unger et al., Systematic review of barriers to cancer trial participation (JNCI 2019): https://doi.org/10.1093/jnci/djy221

## Connected records

- technologies: [Comprehensive genomic profiling](https://onco.cc/technologies/cgp/), [Liquid biopsy (ctDNA)](https://onco.cc/technologies/liquid-biopsy/)
- companies: [Foundation Medicine (Roche)](https://onco.cc/companies/foundation-medicine/), [Guardant Health](https://onco.cc/companies/guardant-health/)
- terms: [Circulating tumour DNA (ctDNA)](https://onco.cc/terms/ctdna/)
- bottlenecks: [Toxicity and quality of life are undervalued](https://onco.cc/bottlenecks/b-toxicity-qol/), [Trials enrol too few, too slowly](https://onco.cc/bottlenecks/b-trial-enrolment/)

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