# NRG Oncology RTOG 0521

Source: https://onco.cc/trials/rtog-0521/  
OnCo record `rtog-0521` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Adding chemotherapy to hormone therapy and radiotherapy for the most aggressive localised prostate cancer improved four-year survival from 89 to 93 percent.

## Summary

RTOG 0521 enrolled 612 men with high-risk non-metastatic prostate cancer between 2005 and 2009; 563 were evaluable. Median PSA was 15.1 ng/mL, 53 percent had a Gleason score of 9 to 10 and 27 percent had cT3 to cT4 disease. Men were randomised to standard long-term androgen suppression with radiotherapy, with or without adjuvant docetaxel.

At a median 5.7 years, 4-year overall survival was 89 percent (95 percent confidence interval 84 to 92) without chemotherapy and 93 percent (90 to 96) with it, hazard ratio 0.69 (90 percent confidence interval 0.49 to 0.97, one-sided p=0.034). There were 59 deaths without chemotherapy and 43 with it, and fewer of those deaths were from prostate cancer (23 against 16). The 6-year rate of distant metastasis was 14 percent without and 9.1 percent with chemotherapy, hazard ratio 0.60 (0.37 to 0.99, two-sided p=0.044), and 6-year disease-free survival was 55 against 65 percent, hazard ratio 0.76 (0.58 to 0.99, p=0.043).

Treatment was well tolerated in both arms. The authors framed the result carefully, as an option to be discussed with selected men rather than a new standard, and it has not displaced abiraterone, which the STAMPEDE high-risk non-metastatic comparison later showed improves metastasis-free survival with a hazard ratio of 0.53.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-25
- Also known as: RTOG 0521; NRG/RTOG 0521
- Registry id: NCT00288080
- Phase: 3
- Setting: High-risk non-metastatic prostate cancer: long-term androgen suppression with radiotherapy, with or without adjuvant docetaxel chemotherapy, with overall survival as the primary endpoint
- Sponsor: NRG Oncology and the Radiation Therapy Oncology Group, funded by the National Cancer Institute
- Enrolled: 612
- Result: Four-year overall survival 93 against 89 percent with adjuvant docetaxel added to androgen suppression and radiotherapy (hazard ratio 0.69, 90 percent confidence interval 0.49 to 0.97); 6-year distant metastasis 9.1 against 14 percent.
- Outcomes: Overall survival at 4 years: Androgen suppression, radiotherapy and docetaxel 93% vs Androgen suppression and radiotherapy 89%, HR 0.69; Distant metastasis at 6 years: Androgen suppression, radiotherapy and docetaxel 9.1% vs Androgen suppression and radiotherapy 14%, HR 0.6
- Replication: GETUG-AFU 12 found a disease-free survival benefit for docetaxel in the same setting but no overall survival benefit; the STAMPEDE high-risk non-metastatic comparison of abiraterone gave a larger metastasis-free survival effect (hazard ratio 0.53).

## Sources

- ClinicalTrials.gov NCT00288080: https://clinicaltrials.gov/study/NCT00288080
- RTOG 0521 (Journal of Clinical Oncology 2019): https://doi.org/10.1200/JCO.18.02158

## Connected records

- cancers: [Localised prostate cancer, high and very high risk](https://onco.cc/cancers/prostate-high-risk/), [Prostate cancer](https://onco.cc/cancers/prostate/)
- technologies: [Androgen deprivation & AR pathway inhibitors](https://onco.cc/technologies/androgen-deprivation/), [Cytotoxic chemotherapy](https://onco.cc/technologies/cytotoxic-chemotherapy/), [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/)
- drugs: [Docetaxel](https://onco.cc/drugs/docetaxel/)
- companies: [NRG Oncology](https://onco.cc/companies/nrg-oncology/)
- terms: [Androgen deprivation therapy (ADT)](https://onco.cc/terms/adt/), [Curative intent vs palliative intent](https://onco.cc/terms/curative-intent/), [Gleason score / Grade Group](https://onco.cc/terms/gleason-grade-group/), [STAMPEDE's arms, and what each one answered](https://onco.cc/terms/prostate-stampede-arms/)
- trials: [CHAARTED (E3805)](https://onco.cc/trials/chaarted/), [STAMPEDE](https://onco.cc/trials/stampede/)

---
JSON: https://onco.cc/api/v1/entities/rtog-0521.json