# SWOG 9916

Source: https://onco.cc/trials/swog-9916/  
OnCo record `swog-9916` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The second trial published the same day as TAX 327, showing the same thing by a different route: docetaxel beats mitoxantrone, though the partner drug it used has since been dropped for its side effects.

## Summary

SWOG 9916 randomly assigned 770 men with metastatic androgen-independent prostate cancer to docetaxel with estramustine or to mitoxantrone with prednisone; 674 were eligible, 338 and 336 respectively.

Median overall survival was 17.5 months with docetaxel and estramustine against 15.6 months with mitoxantrone and prednisone (p=0.02 by log-rank), hazard ratio for death 0.80 (95 percent confidence interval 0.67 to 0.97). Median time to progression was 6.3 against 3.2 months (p<0.001). PSA declines of at least 50 percent occurred in 50 against 27 percent (p<0.001) and objective responses in 17 against 11 percent of men with bidimensionally measurable disease (p=0.30).

The reason estramustine is not used today is in the toxicity table: grade 3 or 4 neutropenic fever (p=0.01), nausea and vomiting (p<0.001) and cardiovascular events (p=0.001) were all more common with docetaxel and estramustine, and pain relief was no better than with mitoxantrone. TAX 327 achieved the same survival gain with prednisone rather than estramustine, so that is the regimen that survived.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-25
- Also known as: SWOG 9916; S9916; INT-0161
- Registry id: NCT00004001
- Phase: 3
- Setting: Metastatic androgen-independent prostate cancer: estramustine 280 mg three times daily on days 1 to 5 with docetaxel 60 mg/m2 on day 2 and dexamethasone, against mitoxantrone 12 mg/m2 with prednisone, in 21-day cycles, with overall survival as the primary endpoint
- Sponsor: SWOG Cancer Research Network, funded by the National Cancer Institute
- Enrolled: 770
- Result: Median overall survival 17.5 against 15.6 months (hazard ratio for death 0.80, 95 percent confidence interval 0.67 to 0.97, p=0.02) and time to progression 6.3 against 3.2 months, at the cost of more neutropenic fever, vomiting and cardiovascular events.
- Outcomes: Overall survival (median): Docetaxel with estramustine 17.5 months vs Mitoxantrone with prednisone 15.6 months, HR 0.8; Time to progression (median): Docetaxel with estramustine 6.3 months vs Mitoxantrone with prednisone 3.2 months
- Replication: TAX 327, published the same day, found the same survival advantage for docetaxel with prednisone and without the extra toxicity of estramustine.

## Sources

- ClinicalTrials.gov NCT00004001: https://clinicaltrials.gov/study/NCT00004001
- SWOG 9916 (New England Journal of Medicine 2004): https://doi.org/10.1056/NEJMoa041318

## Connected records

- cancers: [Metastatic castration-resistant prostate cancer](https://onco.cc/cancers/prostate-mcrpc/), [Prostate cancer](https://onco.cc/cancers/prostate/)
- technologies: [Cytotoxic chemotherapy](https://onco.cc/technologies/cytotoxic-chemotherapy/)
- drugs: [Docetaxel](https://onco.cc/drugs/docetaxel/), [Estramustine](https://onco.cc/drugs/estramustine/), [Mitoxantrone](https://onco.cc/drugs/mitoxantrone/), [Prednisone](https://onco.cc/drugs/prednisone/)
- companies: [SWOG Cancer Research Network](https://onco.cc/companies/swog/)
- terms: [Castration-resistant prostate cancer (CRPC)](https://onco.cc/terms/castration-resistance/), [PSA50 / PSA90 response](https://onco.cc/terms/psa50/)
- trials: [TAX 327](https://onco.cc/trials/tax-327/)

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