# PR status (progesterone receptor by IHC)

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

## TL;DR

PR status is read the same way as ER: 1 percent or more of nuclei staining is positive. It is measured alongside ER, adds to prognosis, and a tumour positive for either receptor counts as hormone-receptor-positive.

## Summary

The ASCO/CAP 2020 guideline applies the same 1 percent nuclear staining threshold to the progesterone receptor as to ER; PR is a downstream target of ER signalling, so PR-negativity in an ER-positive tumour flags a less endocrine-responsive cancer with a worse outlook. Labels use the phrase 'hormone receptor (HR)-positive', which by convention means ER-positive or PR-positive or both, so PR alone can qualify a patient for endocrine therapy and CDK4/6 inhibitors. In endometrial cancer PR expression is used to select progestin therapy under guidelines rather than labels.

## Fields

- Kind: Biomarker
- Last checked: 2026-09-23
- Also known as: PR status; PR-positive; PR positive; PR+; PgR; progesterone receptor status; PR-negative; PR >= 1%
- Tags: biomarker; hormone-receptor

## Sources

- ASCO/CAP estrogen and progesterone receptor testing guideline, 2020 update (Allison et al., J Clin Oncol): https://doi.org/10.1200/JCO.19.02309

## Connected records

- biomarkers: [ER status (oestrogen receptor by IHC)](https://onco.cc/biomarkers/er-status/), [Ki-67 index (proliferation by IHC)](https://onco.cc/biomarkers/ki-67-index/)
- cancers: [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/), [Endometrial cancer](https://onco.cc/cancers/endometrial/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/)
- drugs: [Fulvestrant](https://onco.cc/drugs/fulvestrant/), [Letrozole (and other aromatase inhibitors)](https://onco.cc/drugs/letrozole/), [Palbociclib](https://onco.cc/drugs/palbociclib/), [Tamoxifen](https://onco.cc/drugs/tamoxifen/)
- terms: [Hormone receptor status (ER / PR)](https://onco.cc/terms/hormone-receptor-status/), [Immunohistochemistry (IHC)](https://onco.cc/terms/ihc/)
- targets: [Progesterone receptor (PGR)](https://onco.cc/targets/pgr/)

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JSON: https://onco.cc/api/v1/entities/pr-status.json