# Slamon 1987: HER2 gene amplification marks an aggressive form of breast cancer

Source: https://onco.cc/key-papers/paper-slamon-her2-amplification-science-1987/  
OnCo record `paper-slamon-her2-amplification-science-1987` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Extra copies of the HER2 gene were found in about a quarter to a third of breast cancers and picked out the patients most likely to relapse, the discovery that made HER2 a drug target and a test.

## Summary

Slamon and colleagues measured copies of the HER2/neu gene in 189 primary human breast cancers and found amplification in 53 of them, about 28%, with amplification ranging from 2- to more than 20-fold. In node-positive patients, amplification was a strong and independent predictor of both time to relapse and survival, stronger than most conventional factors. The paper established HER2 as a marker of aggressive disease and, with later work showing the receptor's role in growth signalling, as the target that trastuzumab would hit a decade later.

## Fields

- Kind: Key paper
- Last checked: 2026-09-08
- Journal: Science
- Year: 1987
- DOI: 10.1126/science.3798106
- Authors: Slamon DJ, Clark GM, Wong SG, et al.
- Findings: HER2/neu amplification in 53 of 189 primary breast cancers (about 28%).; Amplification correlated with the number of positive lymph nodes and, in node-positive patients, with shorter time to relapse and shorter survival.; Amplification was an independent prognostic factor in multivariate analysis, stronger than tumour size or hormone receptor status.
- What it means: Every HER2 test, every trastuzumab prescription and the whole HER2-positive breast cancer category trace back to this observation. It is the model for how a genomic marker of bad prognosis became a drug target and then the basis for one of the largest survival gains in solid tumour oncology.
- Caveats: Prognostic effect was clearest in node-positive disease; the node-negative signal was weaker in this dataset.; Measured gene copies by Southern blot; clinical testing later moved to immunohistochemistry and in situ hybridisation with their own cut-offs.

## Sources

- Full text (DOI): https://doi.org/10.1126/science.3798106

## Connected records

- key papers: [American Society of Clinical Oncology/College Of American Pathologists guideline recommendations for immunohistochemical testing of estrogen and progesterone receptors in breast cancer](https://onco.cc/key-papers/paper-asco-cap-er-pr-testing-guideline-jco-2010/), [Slamon 1989: HER2/neu in human breast and ovarian cancer](https://onco.cc/key-papers/paper-slamon-her2-breast-ovarian-science-1989/), [Slamon 2001: adding trastuzumab to chemotherapy for HER2-positive metastatic breast cancer](https://onco.cc/key-papers/paper-slamon-trastuzumab-nejm-2001/), [Yarden and Sliwkowski 2001: untangling the ErbB signalling network](https://onco.cc/key-papers/paper-yarden-sliwkowski-erbb-network-nrmcb-2001/)
- cancers: [HER2-positive breast cancer](https://onco.cc/cancers/breast-her2-positive/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- targets: [HER2](https://onco.cc/targets/her2/)
- people: [Dennis J. Slamon](https://onco.cc/people/dennis-slamon/)
- 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/)

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