# PATHOS

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

## TL;DR

PATHOS is the British trial asking whether people with HPV-positive throat cancer who have robotic surgery can safely be given less radiotherapy, or radiotherapy without chemotherapy, and keep better swallowing.

## Summary

PATHOS enrols patients with HPV-positive oropharyngeal cancer whose tumours can be removed transorally. After surgery and neck dissection, intermediate-risk patients are randomised to 50 or 60 Gy of postoperative radiotherapy, and high-risk patients (extranodal extension or positive margins) to radiotherapy alone or radiotherapy with cisplatin. The phase 2 primary endpoint is patient-reported swallowing at one year; the phase 3 endpoint is overall survival.

The design mirrors ECOG-ACRIN E3311 but goes further by dropping chemotherapy in the high-risk group, which E3311 did not test. It also collects swallowing, feeding-tube use and quality-of-life data prospectively, since function is the reason for de-escalating.

Recruitment across the United Kingdom, Ireland and other European centres continues; the phase 3 answer will decide whether reduced adjuvant treatment after transoral surgery becomes routine rather than a trial option.

## Fields

- Kind: Trial
- Status: active
- Last checked: 2026-09-17
- Registry id: NCT02215265
- Phase: 2/3
- Setting: Resectable HPV-positive oropharyngeal cancer: transoral surgery and neck dissection, then risk-stratified reduction of adjuvant treatment (50 versus 60 Gy in intermediate risk; radiotherapy alone versus chemoradiation in high risk), with swallowing function and survival as endpoints
- Sponsor: Velindre University NHS Trust
- Replication: ECOG-ACRIN E3311 reported two-year progression-free survival near 95 percent with reduced-dose radiotherapy in the same intermediate-risk group.

## Sources

- ClinicalTrials.gov NCT02215265: https://clinicaltrials.gov/study/NCT02215265

## Connected records

- cancers: [HPV-positive oropharyngeal cancer](https://onco.cc/cancers/hpv-positive-oropharyngeal-cancer/), [Oropharyngeal cancer (tonsil and base of tongue)](https://onco.cc/cancers/oropharyngeal-cancer/)
- technologies: [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/), [Transoral robotic surgery (TORS)](https://onco.cc/technologies/tors/)
- drugs: [Cisplatin](https://onco.cc/drugs/cisplatin/)
- terms: [Chemoradiation (chemoradiotherapy, CRT)](https://onco.cc/terms/chemoradiation/), [HPV-positive (p16) head and neck cancer](https://onco.cc/terms/hpv-p16/)
- trials: [ECOG-ACRIN E3311](https://onco.cc/trials/ecog-e3311/)

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JSON: https://onco.cc/api/v1/entities/pathos.json