# Early HER2-positive breast cancer

Source: https://onco.cc/cancers/her2-positive-early-breast-cancer/  
OnCo record `her2-positive-early-breast-cancer` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

HER2-positive breast cancer caught early is usually cured. Chemotherapy with the antibodies trastuzumab and pertuzumab comes before surgery; if the tumour has gone by then, antibodies alone finish the year, and if cancer remains, trastuzumab emtansine or trastuzumab deruxtecan take over. Small tumours get a gentler regimen, and trials now ask how much treatment can be left out.

## Summary

A year of trastuzumab is the foundation. HERA, NSABP B-31 and NCCTG N9831, reported together in 2005, showed that adding trastuzumab to adjuvant chemotherapy cut deaths by about a third, with ten-year overall survival of 84 percent against 75.2 percent in the joint American analysis. PERSEPHONE found six months almost as good as twelve (four-year disease-free survival 89.4 against 89.8 percent) with half the cardiac toxicity, but twelve months remains the standard. For tumours of 3 cm or less without node involvement, the single-arm APT study of twelve weeks of paclitaxel with a year of trastuzumab gave 93 percent seven-year disease-free survival and became the standard for stage I disease without a randomised trial.

For stage II and III disease treatment moved before surgery, where pathological complete response predicts cure and guides what follows. NeoSphere showed that pertuzumab added to trastuzumab and docetaxel raises the complete response rate, and TRAIN-2 (438 patients) showed that carboplatin and paclitaxel with both antibodies matched an anthracycline regimen (complete response 67 against 68 percent) with less cardiac damage, so anthracycline-free regimens became usual. KRISTINE (444 patients) tested replacing chemotherapy with trastuzumab emtansine plus pertuzumab and found fewer complete responses (44.4 against 55.7 percent) and more progression before surgery, a warning against de-escalating on antibody-drug conjugates alone. KATHERINE (1,486 women with residual invasive disease) showed that fourteen cycles of trastuzumab emtansine instead of trastuzumab halved recurrence (three-year invasive disease-free survival 88.3 against 77.0 percent) and improved seven-year overall survival (89.1 against 84.4 percent), and APHINITY (4,805 women) showed adjuvant pertuzumab adds a few points of invasive disease-free survival in node-positive disease and nothing in node-negative disease.

Trastuzumab deruxtecan is now reshaping both ends. DESTINY-Breast05 (1,635 women with residual disease) showed it beats trastuzumab emtansine, with three-year invasive disease-free survival of 92.4 against 83.7 percent (hazard ratio 0.47), and DESTINY-Breast11 (927 women) showed trastuzumab deruxtecan followed by taxane, trastuzumab and pertuzumab before surgery gives more complete responses than dose-dense anthracycline chemotherapy (67.3 against 56.3 percent); the FDA approved both indications in 2026. In the other direction, PHERGain used an early PET scan to identify women who could be cured with antibodies and no chemotherapy at all, with 95.4 percent three-year invasive disease-free survival in the adapted arm and about a third spared chemotherapy. Who can safely skip chemotherapy, whether interstitial lung disease is acceptable in a curative setting, and how hormone receptor-positive HER2-positive tumours should be treated differently are the open questions.

## Fields

- Kind: Cancer
- Last checked: 2026-09-17
- Also known as: Stage I to III HER2-positive breast cancer; Operable HER2-positive breast cancer; HER2-positive breast cancer treated with curative intent
- Tags: subtype-page
- Group: breast
- Burden: Around 15 to 20 percent of breast cancers overexpress HER2 and most are diagnosed at an operable stage; once the subtype with the worst outlook, it now has some of the highest cure rates after a year of HER2-directed therapy.
- Subtypes: Stage I, node-negative HER2-positive tumours of 3 cm or less (paclitaxel and trastuzumab, APT); Stage II to III hormone receptor-negative HER2-positive disease (highest pathological complete response rates); Stage II to III hormone receptor-positive HER2-positive disease (lower response, endocrine therapy added); Residual invasive HER2-positive disease after neoadjuvant therapy (KATHERINE and DESTINY-Breast05 population); Pathological complete response after neoadjuvant therapy (antibodies alone to complete a year)
- Biomarkers: HER2 immunohistochemistry 3+ or in situ hybridisation amplification; Hormone receptor status (co-positive tumours respond less to HER2 therapy alone); Pathological complete response and residual cancer burden at surgery; Left ventricular ejection fraction before and during trastuzumab; Early FDG PET response (PHERGain, investigational); PIK3CA mutation (lower complete response rates, research use)

## Sections of this record

The page is a hub with ten sections in reading order; large sections have their own page. The same plan as JSON: https://onco.cc/api/v1/cancers/her2-positive-early-breast-cancer/sections.json

- Overview (on the hub): The TL;DR, the family this cancer belongs to, the organ, who gets it and what the state of the art is. https://onco.cc/cancers/her2-positive-early-breast-cancer/#overview [4 state-of-the-art points]
- Types and stages (on the hub): Anatomy, the subtypes and how they differ, how it is staged, and where advanced disease spreads. https://onco.cc/cancers/her2-positive-early-breast-cancer/#what-it-is [5 subtypes]
- Symptoms and diagnosis (on the hub): How this cancer shows itself, how the diagnosis is confirmed, and the biomarkers clinicians test for. https://onco.cc/cancers/her2-positive-early-breast-cancer/#finding-it [6 biomarkers]
- Treatment (on the hub): The standard of care by setting, the medicines, surgery and radiotherapy named in it, and the regimens behind them. https://onco.cc/cancers/her2-positive-early-breast-cancer/#treating-it [5 settings, 5 decisions with options]
- Trials and papers (on the hub): Trials recruiting now, the landmark trials, the trials held by this cancer's subtypes, the key papers and what they mean, the latest literature, and the milestones year by year. https://onco.cc/cancers/her2-positive-early-breast-cancer/#evidence [23 trials, 4 key papers, 10 milestones]
- Biology and targets (on the hub): The molecular landscape: the targets and how often each appears, the pathways, the mechanics stages and the preclinical models. https://onco.cc/cancers/her2-positive-early-breast-cancer/#science [2 targets]
- Countries and centres (own page): Cases by country, the UK and NHS pathway and other country lenses, the expert centres with trials on record, and the centres named on this cancer's subtypes. https://onco.cc/cancers/her2-positive-early-breast-cancer/where-you-are/ [16 UK centres]
- Decisions and support (on the hub): The decisions you may face, the aids that walk through them, the warnings on record, the first sixty days and the questions to ask. https://onco.cc/cancers/her2-positive-early-breast-cancer/#living-with-it [22 questions, 6 red cards]
- Pipeline and open problems (own page): Everything in development, the medicines held by this cancer's subtypes, the open problems and what is being done about them, the roadmaps, and what changed on this record. https://onco.cc/cancers/her2-positive-early-breast-cancer/coming/ [9 medicines, 23 trials, 4 open problems]
- Data (own page): Every connected record, the notes, the JSON, Markdown and RDF twins, and where the record came from and when it was checked. https://onco.cc/cancers/her2-positive-early-breast-cancer/data/ [68 connected records]

## Standard of care

- Stage I, small node-negative tumours: Surgery first, then twelve weeks of paclitaxel with a year of trastuzumab (APT). ([Paclitaxel / nab-paclitaxel](https://onco.cc/drugs/paclitaxel/), [Trastuzumab](https://onco.cc/drugs/trastuzumab/), [APT (adjuvant paclitaxel-trastuzumab)](https://onco.cc/trials/apt-trial/))
- Stage II to III, before surgery: Carboplatin, a taxane, trastuzumab and pertuzumab for six cycles without an anthracycline (TRAIN-2), or trastuzumab deruxtecan followed by taxane, trastuzumab and pertuzumab (DESTINY-Breast11). ([Carboplatin](https://onco.cc/drugs/carboplatin/), [Docetaxel](https://onco.cc/drugs/docetaxel/), [Paclitaxel / nab-paclitaxel](https://onco.cc/drugs/paclitaxel/), [Trastuzumab](https://onco.cc/drugs/trastuzumab/), [Pertuzumab](https://onco.cc/drugs/pertuzumab/), [TRAIN-2](https://onco.cc/trials/train-2/), [Trastuzumab deruxtecan](https://onco.cc/drugs/trastuzumab-deruxtecan/), [DESTINY-Breast11](https://onco.cc/trials/destiny-breast11/))
- Pathological complete response at surgery: Trastuzumab, with pertuzumab in node-positive disease, to complete one year (APHINITY, HERA); endocrine therapy if hormone receptor-positive. ([Trastuzumab](https://onco.cc/drugs/trastuzumab/), [Pertuzumab](https://onco.cc/drugs/pertuzumab/), [APHINITY](https://onco.cc/trials/aphinity/), [HERA, NSABP B-31 & NCCTG N9831 (adjuvant trastuzumab)](https://onco.cc/trials/hera-b31-n9831/), [Pathologic complete response (pCR)](https://onco.cc/terms/pcr/))
- Residual invasive disease at surgery: Trastuzumab deruxtecan (DESTINY-Breast05) or trastuzumab emtansine for fourteen cycles (KATHERINE). ([Trastuzumab deruxtecan](https://onco.cc/drugs/trastuzumab-deruxtecan/), [DESTINY-Breast05](https://onco.cc/trials/destiny-breast05/), [Trastuzumab emtansine](https://onco.cc/drugs/trastuzumab-emtansine/), [KATHERINE](https://onco.cc/trials/katherine/), [Residual cancer burden (RCB)](https://onco.cc/terms/rcb/))
- Local therapy and the heart: Breast conservation or mastectomy with sentinel node biopsy, radiotherapy by stage, and echocardiography every three months during trastuzumab. ([Lumpectomy (breast-conserving surgery)](https://onco.cc/terms/lumpectomy/), [Mastectomy](https://onco.cc/terms/mastectomy/), [Sentinel lymph node biopsy](https://onco.cc/technologies/sentinel-node/), [Hypofractionated radiotherapy](https://onco.cc/technologies/hypofractionated-radiotherapy/), [Trastuzumab cardiotoxicity](https://onco.cc/terms/trastuzumab-cardiotoxicity/))

## State of the art

- Response-adapted treatment: what happens after surgery depends on whether the tumour has gone.
- Trastuzumab deruxtecan approved in 2026 for both neoadjuvant and post-neoadjuvant use.
- PET-guided and pathology-guided de-escalation trials are sparing a growing minority of women chemotherapy.
- Anthracyclines have largely left HER2-positive treatment.

## Open problems

- Which women can skip chemotherapy entirely without losing cure.
- Interstitial lung disease from trastuzumab deruxtecan in women who would otherwise have been cured.
- Hormone receptor-positive HER2-positive tumours respond less and the right endocrine and HER2 maintenance is unsettled.
- Cardiac safety of longer and stronger HER2 regimens over decades of survivorship.

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/HER2-positive_breast_cancer
- KATHERINE (NEJM 2019): https://doi.org/10.1056/NEJMoa1814017
- APHINITY (NEJM 2017): https://doi.org/10.1056/NEJMoa1703643
- TRAIN-2 (Lancet Oncology 2018): https://doi.org/10.1016/S1470-2045(18)30570-9
- Wikipedia: https://en.wikipedia.org/wiki/HER2-positive_breast_cancer

## Connected records

- cancers: [HER2-positive breast cancer](https://onco.cc/cancers/breast-her2-positive/), [HER2-positive breast cancer with brain metastases](https://onco.cc/cancers/her2-positive-breast-brain-metastases/)
- trials: [A Clinical Study of Neoadjuvant Treatment With TQB2102 for Injection for Human Epidermal Growth Factor Receptor 2 (HER2) Positive Breast Cancer](https://onco.cc/trials/nct07043725/), [A Phase 2 Neoadjuvant Study of Zanidatamab in Combination With Chemotherapy in Participants With HER2-positive Breast Cancer](https://onco.cc/trials/nct07102381/), [A Phase III Study of KN026 in Combination With HB1801 as Adjuvant Therapy for Resectable HER2-Positive Breast Cancer](https://onco.cc/trials/nct07441460/), [A Phase III, Active-Controlled Study of SHR-A1811 Versus Trastuzumab Emtansine (T-DM1) in HER2-Positive Primary Breast Cancer Participants With Residual Invasive Disease Following Neoadjuvant Therapy](https://onco.cc/trials/nct06126640/), [A Study Evaluating the Efficacy and Safety of Adjuvant Atezolizumab or Placebo and Trastuzumab Emtansine for Participants With HER2-Positive Breast Cancer at High Risk of Recurrence Following Preoperative Therapy](https://onco.cc/trials/nct04873362/), [A Study of BL-M07D1 Versus T-DM1 in the Adjuvant Treatment of HER2-positive Breast Cancer With Residual Invasive Cancer After Neoadjuvant Therapy](https://onco.cc/trials/nct06830889/), [A Study of BL-M07D1 With or Without Pertuzumab Versus Docetaxel + Carboplatin + Trastuzumab + Pertuzumab in Neoadjuvant Therapy for HER2-Positive Brea](https://onco.cc/trials/nct06891833/), [A Study of Neoadjuvant Treatment With TQB2102 for Injection for Human Epidermal Growth Factor Receptor 2 (HER2) Positive Breast Cancer](https://onco.cc/trials/nct06198751/), [APHINITY](https://onco.cc/trials/aphinity/), [APT (adjuvant paclitaxel-trastuzumab)](https://onco.cc/trials/apt-trial/), [ATEMPT](https://onco.cc/trials/atempt/), [Clinical Study of the Efficacy and Safety of BCD-178 and Perjeta® as Neoadjuvant Therapy of HER2-Positive Breast Cancer](https://onco.cc/trials/nct05802225/), [DESTINY-Breast05](https://onco.cc/trials/destiny-breast05/), [DESTINY-Breast11](https://onco.cc/trials/destiny-breast11/), [DV in Combination With Pertuzumab With or Without Toripalimab Neoadjuvant Therapy With HER2-positive Breast Cancer](https://onco.cc/trials/nct06178159/), [HERA, NSABP B-31 & NCCTG N9831 (adjuvant trastuzumab)](https://onco.cc/trials/hera-b31-n9831/), [KATHERINE](https://onco.cc/trials/katherine/), [KRISTINE](https://onco.cc/trials/kristine/), [MARGetuximab Or Trastuzumab (MARGOT)](https://onco.cc/trials/nct04425018/), [NeoSphere](https://onco.cc/trials/neosphere/), [PERSEPHONE](https://onco.cc/trials/persephone/), [PHERGain](https://onco.cc/trials/phergain/), [TRAIN-2](https://onco.cc/trials/train-2/)
- key papers: [APHINITY: adjuvant pertuzumab added to trastuzumab and chemotherapy in early HER2-positive breast cancer](https://onco.cc/key-papers/paper-aphinity-nejm-2017/), [APT: adjuvant paclitaxel and trastuzumab for small, node-negative HER2-positive breast cancer](https://onco.cc/key-papers/paper-apt-tolaney-nejm-2015/), [KATHERINE: switching to T-DM1 when HER2-positive breast cancer survives pre-surgery treatment](https://onco.cc/key-papers/paper-katherine-nejm-2019/), [TRAIN-2: neoadjuvant chemotherapy with or without anthracyclines alongside dual HER2 blockade](https://onco.cc/key-papers/paper-train-2-lancet-oncol-2018/)
- drugs: [Carboplatin](https://onco.cc/drugs/carboplatin/), [Docetaxel](https://onco.cc/drugs/docetaxel/), [Paclitaxel / nab-paclitaxel](https://onco.cc/drugs/paclitaxel/), [Pertuzumab](https://onco.cc/drugs/pertuzumab/), [Trastuzumab](https://onco.cc/drugs/trastuzumab/), [Trastuzumab deruxtecan](https://onco.cc/drugs/trastuzumab-deruxtecan/), [Trastuzumab emtansine](https://onco.cc/drugs/trastuzumab-emtansine/), [Trastuzumab rezetecan](https://onco.cc/drugs/trastuzumab-rezetecan/), [Zanidatamab](https://onco.cc/drugs/zanidatamab/)
- technologies: [HER2 PET](https://onco.cc/technologies/her2-pet/), [Hypofractionated radiotherapy](https://onco.cc/technologies/hypofractionated-radiotherapy/), [MRD / molecular residual disease testing](https://onco.cc/technologies/mrd-testing/), [Sentinel lymph node biopsy](https://onco.cc/technologies/sentinel-node/)
- terms: [Lumpectomy (breast-conserving surgery)](https://onco.cc/terms/lumpectomy/), [Mastectomy](https://onco.cc/terms/mastectomy/), [Pathologic complete response (pCR)](https://onco.cc/terms/pcr/), [Residual cancer burden (RCB)](https://onco.cc/terms/rcb/), [Trastuzumab cardiotoxicity](https://onco.cc/terms/trastuzumab-cardiotoxicity/)
- people: [Luca Gianni](https://onco.cc/people/luca-gianni/)
- biomarkers: [HER2 IHC 3+ (HER2-positive by immunohistochemistry)](https://onco.cc/biomarkers/her2-ihc-3-plus/), [HER2 ISH amplified (ERBB2 gene amplification)](https://onco.cc/biomarkers/her2-ish-amplified/)

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JSON: https://onco.cc/api/v1/entities/her2-positive-early-breast-cancer.json