# QUASAR

Source: https://onco.cc/trials/quasar/  
OnCo record `quasar` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The UK trial that measured exactly how small the benefit of chemotherapy is after surgery for early bowel cancer, turning a default into a conversation.

## Summary

QUASAR asked whether chemotherapy helps people whose bowel cancer was removed but whose risk of recurrence is low, the group for whom the answer had been guesswork. It randomised 3,239 people, nine in ten with stage II disease, to fluorouracil with folinic acid or to observation with chemotherapy held in reserve for recurrence. After a median 5.5 years the relative risk of death was 0.82 (95 percent confidence interval 0.70 to 0.95, p = 0.008) and of recurrence 0.78 (0.67 to 0.91, p = 0.001), with no significant difference by tumour site, stage, sex, age or schedule. The authors translated that into the number that mattered: assuming 20 percent five-year mortality without chemotherapy, an absolute survival gain of about 3.6 percent (1.0 to 6.0).

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-24
- Also known as: Quick and Simple and Reliable; ISRCTN82375386
- Tags: uk; adjuvant; colorectal
- Registry id: ISRCTN82375386
- Phase: 3
- Setting: Adjuvant fluorouracil and folinic acid against observation after apparently curative resection of colon or rectal cancer in people whose indication for chemotherapy was unclear; 2,963 of 3,239 (91 percent) had stage II, node-negative disease; 150 centres in 19 countries, enrolled May 1994 to December 2003
- Sponsor: UK Coordinating Committee on Cancer Research and the Medical Research Council
- Enrolled: 3239
- Result: Relative risk of death 0.82 (0.70 to 0.95, p = 0.008) and of recurrence 0.78 (0.67 to 0.91, p = 0.001) with adjuvant fluorouracil and folinic acid; an absolute five-year survival gain of about 3.6 percent in stage II disease.
- Outcomes: All-cause mortality: Fluorouracil and folinic acid 0.82 relative risk vs Observation 1 relative risk

## Sources

- Lancet 2007: https://europepmc.org/article/MED/18083404
- ISRCTN82375386: https://www.isrctn.com/ISRCTN82375386

## Connected records

- cancers: [Colon cancer (adenocarcinoma of the colon)](https://onco.cc/cancers/colon-cancer/), [Colorectal cancer](https://onco.cc/cancers/colorectal/)
- fronts: [Chemotherapy](https://onco.cc/fronts/chemotherapy/)
- technologies: [Cytotoxic chemotherapy](https://onco.cc/technologies/cytotoxic-chemotherapy/)
- drugs: [Fluorouracil (5-FU)](https://onco.cc/drugs/fluorouracil/), [Leucovorin (folinic acid)](https://onco.cc/drugs/leucovorin/)
- companies: [MRC Clinical Trials Unit at UCL](https://onco.cc/companies/mrc-ctu/)
- institutions: [Oxford Cancer (Oxford University Hospitals and University of Oxford)](https://onco.cc/institutions/oxford-cancer/)
- terms: [Neoadjuvant / adjuvant / perioperative](https://onco.cc/terms/neoadjuvant-adjuvant/)
- trials: [DYNAMIC](https://onco.cc/trials/dynamic/), [IDEA collaboration](https://onco.cc/trials/idea-collaboration/)
- people: [Rachel Kerr](https://onco.cc/people/rachel-kerr/)

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