# Molecular classification of the PORTEC-3 trial: prognosis and benefit from adjuvant chemotherapy by molecular group

Source: https://onco.cc/key-papers/paper-portec-3-molecular-leon-castillo-jco-2020/  
OnCo record `paper-portec-3-molecular-leon-castillo-jco-2020` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Re-analysing the PORTEC-3 trial by molecular class showed that p53-abnormal endometrial cancers gained substantially from adding chemotherapy to radiotherapy, POLE-mutated tumours did well regardless, and the other groups gained little.

## Summary

Molecular classification of 410 high-risk endometrial cancers from the PORTEC-3 trial (chemoradiotherapy versus radiotherapy) into p53-abnormal, POLE-mutated, mismatch repair-deficient and no specific molecular profile groups.

Five-year recurrence-free survival for p53-abnormal tumours was 59 percent with chemoradiotherapy against 36 percent with radiotherapy alone; POLE-mutated tumours had 96 to 100 percent recurrence-free survival in both arms; mismatch repair-deficient and no specific molecular profile groups showed no significant benefit from chemotherapy.

## Fields

- Kind: Key paper
- Last checked: 2026-09-17
- Journal: Journal of Clinical Oncology
- Year: 2020
- DOI: 10.1200/JCO.20.00549
- Authors: León-Castillo A, de Boer SM, Powell ME, et al.
- Findings: p53-abnormal: five-year recurrence-free survival 59 percent vs 36 percent with chemoradiotherapy vs radiotherapy.; POLE-mutated: recurrence-free survival 96 to 100 percent regardless of treatment.
- What it means: Molecular class is now a predictive factor for adjuvant therapy: chemotherapy for p53-abnormal disease, de-escalation for POLE-mutated tumours, and trials of immunotherapy for mismatch repair-deficient disease.
- Caveats: Retrospective subgroup analysis with small molecular groups.; Confirmation is being sought in the RAINBO programme.

## Sources

- J Clin Oncol 2020: https://doi.org/10.1200/JCO.20.00549
- PubMed: https://pubmed.ncbi.nlm.nih.gov/32749941/

## Connected records

- cancers: [Mismatch-repair-deficient endometrial cancer](https://onco.cc/cancers/endometrial-mmr-deficient/), [p53-abnormal endometrial cancer, including uterine serous carcinoma](https://onco.cc/cancers/endometrial-p53-abnormal/), [POLE-ultramutated endometrial cancer](https://onco.cc/cancers/endometrial-pole-ultramutated/)
- trials: [PORTEC-3](https://onco.cc/trials/portec-3/)
- journals: [Journal of Clinical Oncology](https://onco.cc/journals/jco/)

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