# TIL-based omission of chemotherapy in stage I TNBC

Source: https://onco.cc/ideas/idea-til-guided-deescalation/  
OnCo record `idea-til-guided-deescalation` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Small triple-negative tumours packed with immune cells almost never come back. The idea is to skip chemotherapy for those patients.

## Summary

Small triple-negative tumours packed with immune cells almost never come back, so this idea skips chemotherapy for stage I TNBC with high stromal TILs and treats with surgery and radiation alone. TILs mark a tumour already under immune control, and pooled cohorts such as ETNA, OPTimal and TIL-CHOICE suggest chemotherapy adds toxicity without measurable benefit in this group. A prospective single-arm trial with a non-inferiority boundary, central AI-assisted TIL scoring and ctDNA surveillance as a safety net would be needed before practice changes. The idea is being tested at scale, draws on histopathology and digital pathology AI, and is linked from the idea Payer-funded trials that omit surgery or radiotherapy in low-risk patients.

## Fields

- Kind: Idea
- Last checked: 2026-09-04
- Hypothesis: Stage I TNBC with sTILs ≥50% (or ≥30% with pT1a-b) managed with surgery and radiation alone has 5-year iDFS non-inferior to chemotherapy.
- Rationale: TILs mark a tumour already under immune control; chemotherapy adds toxicity without measurable benefit in this group.
- Proposed test: Run a single-arm prospective trial with a non-inferiority boundary (e.g., 5-year iDFS >90%), central AI-assisted TIL scoring, and ctDNA surveillance as a safety net.
- Maturity: being-tested-at-scale

## Sources

- Leon-Ferre et al., Tumour-infiltrating lymphocytes in triple-negative breast cancer treated without chemotherapy (JAMA 2024): https://doi.org/10.1001/jama.2024.3056

## Connected records

- cancers: [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- technologies: [Digital pathology & AI](https://onco.cc/technologies/digital-pathology-ai/), [Histopathology & immunohistochemistry](https://onco.cc/technologies/histopathology-ihc/)
- terms: [Tumour-infiltrating lymphocytes (TILs)](https://onco.cc/terms/tils/)
- key papers: [Tumor-Infiltrating Lymphocytes in Triple-Negative Breast Cancer](https://onco.cc/key-papers/paper-leon-ferre-tils-tnbc-no-chemotherapy-jama-2024/)
- ideas: [Payer-funded trials that omit surgery or radiotherapy in low-risk patients](https://onco.cc/ideas/idea-fund-omission-deescalation-trials/)

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