# PAM50 / intrinsic subtypes

Source: https://onco.cc/terms/pam50/  
OnCo record `pam50` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A 50-gene test that sorts breast cancers into luminal A, luminal B, HER2-enriched, and basal-like.

## Summary

PAM50 is a 50-gene expression test that sorts breast cancers into the intrinsic subtypes luminal A, luminal B, HER2-enriched and basal-like. It derives from the molecular portraits of Perou and Sørlie and is commercialised as Prosigna. Basal-like largely overlaps with Triple-negative breast cancer (TNBC), HER2-enriched predicts response to HER2 blockade regardless of IHC, and the luminal subtypes matter for HR-positive / HER2-negative breast cancer. The test depends on RNA sequencing & expression profiling and is referenced by the TCGA Pan-Cancer Atlas paper, the organ tropism pathway on seed and soil, and an idea on omitting radiotherapy for very low-risk breast cancer. Institutions associated with it include UNC Lineberger Comprehensive Cancer Center and SOLTI Cancer Research Group.

## Fields

- Kind: Term
- Last checked: 2026-09-04
- Also known as: PAM50 molecular subtypes; PAM50 gene set; PAM50 subtypes; intrinsic subtype; Basal-like; PAM50 Basal; basal-like subtype; HER2-enriched; PAM50 Her2; HER2-enriched subtype; Normal-like; PAM50 Normal; normal-like subtype

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Breast_cancer_classification
- PAM50 intrinsic-subtype predictor (Parker et al., J Clin Oncol 2009): https://doi.org/10.1200/JCO.2008.18.1370

## Connected records

- cancers: [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- technologies: [RNA sequencing & expression profiling](https://onco.cc/technologies/rna-seq/)
- key papers: [Clinical, pathological, and PAM50 gene expression features of HER2-low breast cancer](https://onco.cc/key-papers/paper-schettini-her2-low-features-npj-breast-cancer-2021/), [Comparison of breast cancer molecular features and survival by African and European ancestry in The Cancer Genome Atlas](https://onco.cc/key-papers/paper-huo-tcga-ancestry-breast-jama-oncol-2017/), [Comprehensive molecular portraits of human breast tumours](https://onco.cc/key-papers/paper-tcga-breast-molecular-portraits-nature-2012/), [Gene expression patterns of breast carcinomas distinguish tumor subclasses with clinical implications](https://onco.cc/key-papers/paper-sorlie-breast-carcinoma-subclasses-pnas-2001/), [Molecular portraits of human breast tumours](https://onco.cc/key-papers/paper-perou-molecular-portraits-breast-tumours-nature-2000/), [Repeated observation of breast tumor subtypes in independent gene expression data sets](https://onco.cc/key-papers/paper-sorlie-repeated-observation-subtypes-brca1-basal-pnas-2003/), [Supervised risk predictor of breast cancer based on intrinsic subtypes](https://onco.cc/key-papers/paper-parker-j-clin-oncol/), [TCGA Pan-Cancer Atlas: 10,000 tumours across 33 cancer types, classified by molecular features](https://onco.cc/key-papers/paper-tcga-pancancer-atlas-cell-2018/), [Unravelling triple-negative breast cancer molecular heterogeneity using an integrative multiomic analysis](https://onco.cc/key-papers/paper-bareche-tnbc-multiomic-heterogeneity-ann-oncol-2018/)
- roadmaps: [Triple-negative breast cancer roadmap: from a remainder defined by three negative tests to immunotherapy, antibody-drug conjugates and the residual disease problem](https://onco.cc/roadmaps/tnbc-roadmap/)
- targets: [Androgen receptor](https://onco.cc/targets/androgen-receptor/), [DNAJC12](https://onco.cc/targets/dnajc12/)
- ideas: [Make skipping radiotherapy the default for very low-risk breast cancer](https://onco.cc/ideas/idea-prev-omit-radiotherapy-low-risk-breast-default/)
- institutions: [Cancer Research UK Cambridge Centre / CRUK Cambridge Institute](https://onco.cc/institutions/cruk-cambridge-centre/), [Hospital Clínic de Barcelona / IDIBAPS](https://onco.cc/institutions/hospital-clinic-barcelona/), [Skåne University Hospital / Lund University Cancer Centre](https://onco.cc/institutions/lund-skane/), [UNC Lineberger Comprehensive Cancer Center](https://onco.cc/institutions/unc-lineberger/)
- pathways: [Organ tropism: seed and soil](https://onco.cc/pathways/organ-tropism-seed-soil/)
- companies: [SOLTI Cancer Research Group](https://onco.cc/companies/solti/)
- terms: [Logistic regression and nearest-centroid classifiers](https://onco.cc/terms/logistic-regression-term/)

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