# [68Ga]Ga-NOTA-T4 PET/CT imaging of TROP2 expression in patients with HER2-negative breast cancer

Source: https://onco.cc/key-papers/paper-liu-ga68-nota-t4-breast-eur-j-nucl-med-2026/  
OnCo record `paper-liu-ga68-nota-t4-breast-eur-j-nucl-med-2026` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A TROP2 PET scan in breast cancer showed that how much TROP2 a cancer has can change after hormone therapy or chemotherapy, in opposite directions in different subtypes.

## Summary

Retrospective review of 42 patients with HER2-negative breast cancer at Huashan Hospital, Fudan University, imaged with [68Ga]Ga-NOTA-T4 PET/CT between September 2023 and March 2025, 27 of whom also had [18F]FDG PET/CT. Detection of patients and metastatic lesions was comparable with FDG. In luminal B disease, patients who had received endocrine therapy or chemotherapy had higher uptake than untreated patients (SUVmax 5.20 ± 5.07 against 3.36 ± 3.52, p = 0.008); a similar trend in luminal A was not significant (p = 0.241); in triple-negative disease, treated patients had lower uptake (3.02 ± 2.35 against 7.63 ± 5.64, p = 0.008).

## Fields

- Kind: Key paper
- Last checked: 2026-11-04
- Journal: European Journal of Nuclear Medicine and Molecular Imaging
- Year: 2026
- DOI: 10.1007/s00259-026-07796-4
- Authors: Liu Y, Chu Z, Jin X, et al.
- Findings: Comparable detection to FDG.; Luminal B: higher uptake after treatment (p = 0.008).; TNBC: lower uptake after treatment (p = 0.008).
- What it means: TROP2 is not a fixed property of a breast cancer; treatment can move it. A test of TROP2 taken at diagnosis may not describe what is left later.
- Caveats: Retrospective, single centre, cross-sectional comparison of treated and untreated patients rather than the same patients over time.

## Sources

- Liu et al., Eur J Nucl Med Mol Imaging 2026: https://doi.org/10.1007/s00259-026-07796-4
- PubMed: https://pubmed.ncbi.nlm.nih.gov/41781717/

## Connected records

- cancers: [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- fronts: [Imaging](https://onco.cc/fronts/imaging/)
- technologies: [PET (positron emission tomography)](https://onco.cc/technologies/pet/), [TROP2 PET](https://onco.cc/technologies/trop2-pet/)
- targets: [TROP2](https://onco.cc/targets/trop2/)
- drugs: [68Ga-NOTA-T4](https://onco.cc/drugs/ga68-nota-t4/)
- bottlenecks: [Naming which clone or phenotype is left after treatment](https://onco.cc/bottlenecks/b-subclone-attribution-residual-disease/)

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