# Therasse 2000: RECIST, the standard rules for measuring whether a tumour responds

Source: https://onco.cc/key-papers/paper-therasse-recist-jnci-2000/  
OnCo record `paper-therasse-recist-jnci-2000` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The guideline that defined how trials decide a tumour has shrunk, stayed stable or grown, using the longest diameter of a few measured lesions, so results from different trials can be compared.

## Summary

RECIST (Response Evaluation Criteria in Solid Tumours) was drawn up by the EORTC, the US National Cancer Institute and the National Cancer Institute of Canada to replace the older WHO criteria, which used two perpendicular diameters. RECIST measures only the longest diameter of each target lesion and sums them: a partial response is a decrease of at least 30% in the sum, progressive disease an increase of at least 20%, and stable disease anything between. It set rules for which lesions are measurable, how many to follow and how to confirm responses, and its revision as RECIST 1.1 in 2009 reduced the number of target lesions and added rules for lymph nodes.

## Fields

- Kind: Key paper
- Last checked: 2026-09-08
- Journal: JNCI: Journal of the National Cancer Institute
- Year: 2000
- DOI: 10.1093/jnci/92.3.205
- Authors: Therasse P, Arbuck SG, Eisenhauer EA, et al.
- Findings: Response is judged on the sum of the longest diameters of selected target lesions rather than the products of two diameters.; Partial response: at least a 30% decrease in the sum; progressive disease: at least a 20% increase or new lesions; stable disease in between.; Revised in 2009 as RECIST 1.1: a maximum of five target lesions, two per organ, and lymph node criteria based on the short axis.
- What it means: Almost every response rate and progression-free survival figure quoted on this site rests on RECIST. Knowing that a partial response means a 30% shrinkage of a few measured lesions, not a cure, helps read trial results honestly, and the criteria's limits with immunotherapy led to iRECIST for delayed and mixed responses.
- Caveats: Anatomical size does not capture necrosis or metabolic change, so RECIST can misjudge drugs that act without shrinking tumours.; Immunotherapy pseudoprogression prompted modified criteria (irRC, iRECIST).; Measurement variability between readers is real and affects small changes.

## Sources

- Full text (DOI): https://doi.org/10.1093/jnci/92.3.205
- RECIST 1.1 (Eisenhauer 2009): https://doi.org/10.1016/j.ejca.2008.10.026

## Connected records

- terms: [Complete response](https://onco.cc/terms/complete-response/), [Objective response rate (ORR)](https://onco.cc/terms/orr/), [Partial response](https://onco.cc/terms/partial-response/), [Progressive disease and radiographic progression](https://onco.cc/terms/progressive-disease/), [RECIST](https://onco.cc/terms/recist/)

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