Latest Cancer TreatmentsDr. Mohammadreza Dabiri
Dr. Mohammadreza Dabiriفارسی
Questions and answers

Is chemotherapy necessary for breast cancer?

Not always; the decision depends on the type of tumour, its size and the lymph nodes, genomic testing of the tumour, menopause and general health

Updated: 29 October 202612 min read20 references
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Short answer

Not always. Many women with early hormone-positive, HER2-negative breast cancer are treated with surgery, radiotherapy if needed and hormone tablets, and chemotherapy adds no benefit to their treatment; a genomic test on the tumour (such as Oncotype DX) helps to identify these women [3, 5]. But in most HER2-positive and triple-negative cancers, drug treatment that includes chemotherapy increases the chance of cure [9, 10, 13]. Your treatment team makes the final decision based on the type and size of the tumour, lymph node involvement, your age and your general health [9].

Key points

  • Not every woman with breast cancer needs chemotherapy. Chemotherapy after surgery aims to destroy cancer cells that may have stayed in the body, and chemotherapy before surgery aims to shrink the tumour [1].
  • The benefit of chemotherapy depends on the risk of the cancer coming back: on average, chemotherapy lowers the risk of dying from breast cancer by about a third; so when the risk is low to begin with, the benefit is small too [2].
  • In hormone-positive, HER2-negative cancer that has not reached the lymph nodes, about 7 in 10 women can be treated without chemotherapy, based on a genomic test of the tumour [4].
  • In HER2-positive and triple-negative cancer, chemotherapy is usually given together with a targeted drug or immunotherapy, often before surgery, and it increases the chance of cure [9, 10, 13].
  • Age alone does not decide; in younger and older women alike, the risk from the disease and general health are what matter most [9].

What does chemotherapy do in breast cancer?

Surgery removes the tumour, but a few cancer cells may have stayed in the body. Chemotherapy after surgery aims to destroy these cells and lower the chance of the cancer coming back. Sometimes chemotherapy is given before surgery to shrink the tumour [1].

In a large review of nearly 100,000 women in 123 studies, common multi-drug chemotherapy lowered the risk of dying from breast cancer by about a third on average. But the benefit each woman actually gets depends on her own risk of the cancer coming back: when this risk is low, chemotherapy adds only a little to her treatment [2]. That is why your doctor first estimates the risk of your cancer coming back and then decides about chemotherapy. Chemotherapy also has side effects that have to be weighed in this decision; see What are the side effects of chemotherapy?

For physiciansEBCTCG 2012
For physicians

EBCTCG 2012 (123 trials, about 100,000 women): compared with no chemotherapy, the breast cancer mortality RR was 0.64 with CAF, 0.78 with standard 4AC and 0.76 with standard CMF; adding 4 cycles of a taxane to a fixed anthracycline-based control regimen gave an RR of 0.86. Proportional risk reductions were largely independent of age (up to at least 70 years), nodal status, tumour size and grade, ER status and tamoxifen use; the absolute 10-year gain therefore depends on the absolute risk without chemotherapy (in ER-positive disease, the risk that remains with appropriate endocrine therapy), and a low absolute risk means a low absolute benefit [2]. To convert relative into absolute reductions and NNT: NNT calculator.

How is the decision about chemotherapy made?

  1. 1

    The type of tumour in the pathology report

    The most important point is whether the tumour has hormone receptors (ER and PR) and HER2; these markers divide breast cancer into the main groups: hormone-positive, HER2-positive and triple-negative [9]. To understand these terms, see ER, PR, HER2 and Ki-67 on a breast cancer report: what do they mean?

  2. 2

    Tumour size and lymph nodes

    A larger tumour or cancer in the lymph nodes of the armpit means a higher risk of the cancer coming back; the stage of the disease is also worked out from these [9]. See What are the stages of cancer?

  3. 3

    A genomic test on the tumour, only in hormone-positive cancer

    If, after all these factors have been considered, it is still not clear whether chemotherapy is needed, a test on a tumour sample (such as Oncotype DX or MammaPrint) helps [9]. These tests are not used for HER2-positive or triple-negative cancer [8].

  4. 4

    Menopause, general health and age

    Whether you have been through the menopause, other illnesses and your physical fitness all affect the decision; but age alone is not the main criterion [9].

  5. 5

    Your own views and wishes

    You should take part in every decision about your treatment and receive clear, complete explanations [9]. Weigh the benefits and side effects together with your doctor.

Hormone-positive cancer: a genomic test on the tumour makes the decision clearer

Hormone-positive, HER2-negative breast cancer is the most common type; in the United States, about 7 in 10 breast cancers were of this type [20]. In this cancer, hormone tablets are the backbone of treatment and all these women receive them [9]. The question is whether chemotherapy adds anything to the hormone tablets. Tests such as Oncotype DX and MammaPrint measure the activity of a set of genes in a tumour sample and show how likely the cancer is to come back [3, 6].

  • No lymph nodes involved: in a large study of more than 10,000 women, those with a low or intermediate Oncotype DX score did just as well with hormone tablets alone as with chemotherapy plus tablets; only in some women aged 50 or younger with a score of 16 to 25 did chemotherapy bring a small benefit [3]. With a high score (26 to 100), chemotherapy together with hormone tablets is considered [4].
  • 1 to 3 lymph nodes involved: in women past the menopause with a score of 25 or lower, chemotherapy added no benefit; but in women who had not yet reached the menopause, chemotherapy clearly lowered the risk of the cancer coming back [5].
  • MammaPrint: in women whose tumour size and grade suggested a high risk but whose genomic risk was low, about 19 in 20 were alive without the cancer spreading 5 years later, without chemotherapy [6]. With longer follow-up, chemotherapy made almost no difference in the women of this group who were over 50, and it may bring a small benefit in women aged 50 or younger [7].
  • 4 or more lymph nodes involved: there are no data on using these tests in this group, and chemotherapy is usually considered [8, 9].

If no genomic test is done, your doctor decides with the help of the pathology report (such as tumour grade and Ki-67), the size of the tumour and lymph node involvement [8, 9]. For what an Oncotype DX score means and how the two tests differ, see Treating hormone receptor-positive breast cancer.

For physiciansTAILORx
For physicians

TAILORx (10,273 women with HR-positive/HER2-negative, node-negative disease; 6,711 with RS 11 to 25 were randomised): endocrine therapy alone was non-inferior (iDFS HR 1.08; 95% CI 0.94 to 1.24; P=0.26); at 9 years, iDFS 83.3% vs 84.3%, freedom from distant recurrence 94.5% vs 95.0% and OS 93.9% vs 93.8%. The chemotherapy benefit varied with the combination of RS and age (P=0.004), and some benefit was seen at age 50 or younger with RS 16 to 25 [3]. According to the NCI, about 70% of this population can forgo chemotherapy; with RS 26 to 100, distant recurrence was 13% despite chemotherapy plus endocrine therapy [4]. At age 50 or younger on endocrine therapy alone, 9-year distant recurrence with an intermediate RS was 12.3% with high clinical risk (based on size and grade) and 4.7% with low clinical risk [19].

RxPONDER (5,083 women, 1 to 3 positive nodes, RS ≤25; 33.2% premenopausal): postmenopausal, 5-year iDFS 91.9% with endocrine therapy alone vs 91.3% with chemoendocrine therapy (HR 1.02; 95% CI 0.82 to 1.26); premenopausal, 89.0% vs 93.9% (HR 0.60; 0.43 to 0.83; P=0.002), with a similar gain in distant relapse-free survival (HR 0.58); the relative benefit did not increase with rising RS [5].

MINDACT (6,693 women, 0 to 3 positive nodes): with high clinical/low genomic risk (1,550 patients, 23.2%), 5-year distant metastasis-free survival without chemotherapy was 94.7% (95% CI 92.5 to 96.2), 1.5 percentage points lower than with chemotherapy [6]. At a median follow-up of 8.7 years, 8-year DMFS was 92.0% with chemotherapy vs 89.4% without (HR 0.66); in the exploratory HR-positive/HER2-negative analysis, the absolute difference was 5.0 percentage points at age 50 or younger (95% CI −0.5 to 10.4) and 0.2 percentage points above 50; the authors suggest part of the benefit in younger women may come from chemotherapy-induced ovarian function suppression [7].

ASCO 2022: Oncotype DX, MammaPrint, Breast Cancer Index and EndoPredict for postmenopausal patients or those over 50 with ER-positive/HER2-negative disease and N0 or 1 to 3 positive nodes; in premenopausal patients, only Oncotype DX and only in N0; premenopausal patients with 1 to 3 positive nodes benefit from chemotherapy regardless of the genomic result; no data for 4 or more positive nodes; in postmenopausal patients, when no genomic test is done, Ki-67 combined with other parameters or IHC4; no assay is recommended for HER2-positive or triple-negative disease [8]. ESMO (Pan-Asian adaptation 2024): most luminal A-like tumours do not need chemotherapy, except with a high disease burden [I, A]; when in doubt, gene expression assays or endocrine response assessment [I, B]; luminal B-like: chemotherapy followed by endocrine therapy, and chemotherapy in high clinical risk (e.g. multiple positive nodes, premenopausal node-positive, locally advanced) [I, A] [9].

HER2-positive and triple-negative cancer: why is chemotherapy usually needed?

Triple-negative: this cancer behaves more aggressively, and its risk of coming back is higher in the first few years after diagnosis [15]. Hormone tablets do not work in it, because the tumour has no hormone receptors [14]. That is why chemotherapy, and in many patients immunotherapy with it, is the main drug treatment [9]. Only in very small triple-negative tumours (5 mm or less) that have not reached the lymph nodes, or in a few special low-risk types seen under the microscope, may chemotherapy not be needed [9].

HER2-positive: anti-HER2 drugs such as trastuzumab are given together with chemotherapy [9]. In two large studies, adding trastuzumab to chemotherapy after surgery almost halved the risk of the cancer coming back [10]. When a HER2-positive tumour is small (1 cm or less) and the lymph nodes are not involved, surgery usually comes first, followed by lighter chemotherapy (12 weeks of weekly paclitaxel) with one year of trastuzumab [9]. In a study of women with tumours of 3 cm or smaller and no lymph node involvement, more than 9 in 10 women treated this way were alive without the cancer coming back after 7 years [11].

Treatment before surgery: in HER2-positive cancer larger than 2 cm or with lymph node involvement, and in triple-negative cancer larger than 1 cm or with lymph node involvement, drug treatment is usually given before surgery [9]. In stage 2 and 3 triple-negative cancer, with chemotherapy plus immunotherapy (pembrolizumab) before surgery, no cancer was left at the time of surgery in about 2 in 3 patients, more often than with chemotherapy alone, and more patients stayed alive [12, 13]. If some cancer is still left after treatment before surgery, the treatment after surgery is changed to lower the risk of it coming back; for example, the drug trastuzumab emtansine in HER2-positive cancer [16] and capecitabine tablets in triple-negative cancer [17].

Read more: Treating HER2-positive breast cancer and What is the best treatment for triple-negative breast cancer?

For physiciansHER2-positive.
For physicians

HER2-positive. NSABP B-31/NCCTG N9831 (joint analysis): adding 52 weeks of trastuzumab to AC followed by paclitaxel, HR for events 0.48 (P<0.0001), an absolute difference of 12% in 3-year disease-free survival and a 33% reduction in the risk of death; 3-year cumulative incidence of class III or IV heart failure or cardiac death 4.1% in B-31 and 2.9% in N9831 [10]. APT (410 patients, tumours ≤3 cm and N0; paclitaxel 80 mg/m² with trastuzumab for 12 weeks, then trastuzumab for 9 months): 7-year DFS 93% (95% CI 90.4 to 96.2), 4 distant recurrences (1.0%) and 7-year OS 95% [11]. ESMO: anti-HER2 therapy (with chemotherapy at the start) for 12 months [I, A]; stage II–III (e.g. T larger than 2 cm or N-positive): neoadjuvant chemotherapy with trastuzumab–pertuzumab is preferred [I, A]; stage I (T1a–b N0): primary surgery [III, B] followed by 12 weeks of paclitaxel and one year of trastuzumab [III, B]; residual disease after neoadjuvant therapy: T-DM1 for up to 14 cycles [I, A] [9]. KATHERINE: 3-year iDFS 88.3% vs 77.0% (HR 0.50; 95% CI 0.39 to 0.64) [16]. Regimens: APT · TCHP · T-DM1.

Triple-negative. ESMO: chemotherapy with or without pembrolizumab [I, A], except some special histological subtypes with N0 (secretory or adenoid cystic carcinoma) or very low clinical risk (pT1a pN0) [II, B]; 12 to 24 weeks (4 to 8 cycles) [I, A]; cT1c–4 N0 or any N-positive: neoadjuvant treatment preferred [I, A]; cT2–4 N0 or any N-positive (stage II–III): neoadjuvant chemotherapy with pembrolizumab [I, A]; residual disease without prior ICI: capecitabine for 6 to 8 cycles [I, A]; gBRCA with high risk: one year of olaparib [I, A] [9]. KEYNOTE-522: pCR 64.8% vs 51.2% [12]; 60-month OS 86.6% vs 81.7% (P=0.002; median follow-up 75.1 months) [13]. CREATE-X, triple-negative subgroup: DFS 69.8% vs 56.1% (HR 0.58) and OS 78.8% vs 70.3% (HR 0.52) [17]. EBCTCG 2011: tamoxifen had little or no effect in ER-negative disease [14]. In the Dent cohort, triple-negative disease carried a higher risk of distant recurrence (HR 2.6) and death (HR 3.2) within the first 5 years, with distant recurrence peaking at about year 3 [15]. Regimens: KEYNOTE-522 · AC followed by paclitaxel · TC · Capecitabine (CREATE-X).

Age, menopause and older women

Younger women and those before the menopause: in these women, chemotherapy has brought a benefit in some groups where it did not in women past the menopause; for example, when 1 to 3 lymph nodes are involved [5, 8]. Researchers think part of this benefit may come from chemotherapy stopping the ovaries from working [7]. Chemotherapy may affect fertility; if you would like to have children in the future, talk to your doctor about ways to preserve fertility before treatment starts [9] (Fertility and sex during cancer treatment).

Older women: age alone is not a reason to leave out chemotherapy. What counts is "biological age", meaning general health and physical fitness, not just the number of years; and a geriatric assessment is recommended before the decision [9]. Lighter treatments are considered for frailer women, but a woman who is fit for standard chemotherapy should receive that standard treatment [9]. In a study of women aged 65 and over, when lighter treatment (capecitabine tablets alone) was given instead of standard chemotherapy, the cancer came back almost twice as often [18].

For physiciansSpecialist notes
For physicians

ESMO: age should be considered together with other factors and should not be the primary determinant of the decision [IV, A]; treatment of older patients should be adapted to biological rather than chronological age, with less aggressive regimens in frail patients, and a standard multidrug regimen in patients suitable for standard chemotherapy [II, B]; a geriatric assessment before treatment decisions [II, A]; fertility and fertility preservation should be discussed with younger premenopausal patients before any systemic treatment [V, A] [9]. CALGB 49907 (aged 65 and over, stage I to IIIB; CMF or AC vs capecitabine): HR for recurrence or death with capecitabine 2.09 (95% CI 1.38 to 3.17; P<0.001); 3-year RFS 68% vs 85% and OS 86% vs 91%; moderate to severe toxicity in 64% with standard chemotherapy vs 33% with capecitabine [18]. Tools: Geriatric assessment before chemotherapy · G8 screening · CARG score.

When is it safe to go without chemotherapy, and when is leaving it out dangerous?

Chemotherapy in early breast cancer, as a general rule
SituationChemotherapy is usuallyWhy
Hormone-positive and HER2-negative, no nodes involved, a genomic score of 25 or lower over age 50, or 15 or lower at age 50 or youngerNot neededHormone tablets alone did just as well [3, 4]
Hormone-positive and HER2-negative, 1 to 3 nodes involved, past the menopause, score of 25 or lowerNot neededChemotherapy added no benefit [5]
Hormone-positive and HER2-negative, aged 50 or younger with a score of 16 to 25, or before the menopause with 1 to 3 nodes involvedWeighed up with your doctor; often beneficialIn these groups, chemotherapy lowered the risk of the cancer coming back [3, 5]
Hormone-positive with a high genomic score, or 4 or more nodes involvedUsually consideredThe risk of the cancer coming back is high [4, 9]
HER2-positiveUsually yes, with an anti-HER2 drugTrastuzumab with chemotherapy almost halved the risk of the cancer coming back; a lighter regimen for small tumours [9, 10, 11]
Triple-negative, larger than 5 mm or with nodes involvedYes, often before surgery and with immunotherapyChemotherapy is the main drug treatment and hormone tablets do not work [9, 13, 14]
Very small triple-negative (5 mm or less) with no nodes involvedMay not be neededThe risk of the cancer coming back is very low [9]

This table is only a guide. The exact size of the tumour, its grade, other illnesses and your wishes also affect the decision [9].

Before leaving out chemotherapy

If your doctor has recommended chemotherapy and you are worried about its side effects, do not drop it on your own or put off starting it. Ask your doctor to explain the benefits and side effects for you, in numbers, and if you are unsure, ask another treatment team for their opinion as well. In high-risk cancers, going without chemotherapy can lower the chance of cure [2, 10, 13].

Questions to ask your doctor

  • "Which type of cancer do I have (hormone-positive, HER2-positive or triple-negative), and what is its stage?"
  • "What is the risk of my cancer coming back with and without chemotherapy? Out of 100 women like me, for how many does chemotherapy make a difference?"
  • "Would a genomic test on the tumour (such as Oncotype DX) help with my decision?"
  • "Will I have chemotherapy before or after surgery? How many cycles, and which drugs?"
  • "What side effects might I have, and what can be done to reduce them? Will it affect my fertility?"
  • "If I do not have chemotherapy, what other treatments do I have, and what would I be giving up?"

To prepare, read: What is chemotherapy and how is it given?, How many chemotherapy sessions will I need? and Your first chemotherapy session.

Frequently asked questions

Is chemotherapy needed for stage 1 breast cancer?

It depends on the type of tumour. In hormone-positive, HER2-negative cancer that has not reached the lymph nodes, most women do not need chemotherapy, and a genomic test on the tumour helps in borderline cases [4, 9]. In stage 1 HER2-positive cancer, lighter chemotherapy is usually given with trastuzumab, and in triple-negative cancer, too, chemotherapy is recommended except for very small tumours [9].

Can I take hormone tablets instead of chemotherapy?

In hormone-positive cancer with a low or intermediate risk, yes; in large studies, hormone tablets alone worked just as well [3, 5]. But hormone tablets do not work in cancer without hormone receptors (such as triple-negative cancer) [14], and in high-risk hormone-positive cancer, chemotherapy is usually recommended alongside them [9].

What happens if I do not have chemotherapy?

The answer depends on the risk of your cancer coming back. On average, chemotherapy lowers the risk of dying from breast cancer by about a third; so in a high-risk cancer, going without it means losing an important part of the chance of cure, while in a low-risk cancer its benefit is small [2]. Ask your doctor to explain this for your own situation.

Does everyone need an Oncotype DX test?

No. This test is for hormone-positive, HER2-negative cancer, when it is not clear without it whether chemotherapy is needed [9]. It is not used for HER2-positive or triple-negative cancer, and there are no data on its use in women with 4 or more lymph nodes involved [8].

Is chemotherapy better before or after surgery?

In many HER2-positive and triple-negative cancers that are larger or have reached the lymph nodes, treatment before surgery is preferred [9]. One advantage is that the doctor can see how well the tumour has responded, and if some cancer is left, the treatment after surgery is changed to lower the risk of it coming back [16, 17].

Is chemotherapy needed at age 70 or older?

Sometimes, yes. Age alone does not decide; general health, physical fitness and the risk from the disease matter more, and a geriatric assessment is recommended before the decision [9]. In a study of women aged 65 and over, standard chemotherapy worked better than a lighter treatment [18].

Does chemotherapy cause infertility?

It may affect fertility. That is why fertility and ways to preserve it should be discussed with younger women before any drug treatment starts [9]. See Fertility and sex during cancer treatment.

Scientific evidence

Key studies in the evidence library

7 items
Clinical trial · Phase 3

Adjuvant Chemotherapy Guided by a 21-Gene Expression Assay in Breast Cancer

N Engl J Med · 2018
HR 1.08iDFS (endocrine therapy vs chemo + endocrine)
Summary
Meta-analysis

Comparisons between different polychemotherapy regimens for early breast cancer: meta-analyses of long-term outcome among 100 000 women in 123 randomised trials

The Lancet · 2012
RR 0.86 (SE 0.04)Adding four cycles of a taxane to a fixed anthracycline-based control regimen (extended treatment) – breast cancer mortality
Summary
Clinical guideline

Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with early breast cancer

ESMO Open · 2024
Summary
Clinical trial

Trastuzumab plus Adjuvant Chemotherapy for Operable HER2-Positive Breast Cancer

N Engl J Med · 2005
133 events in the trastuzumab group vs 261 events in the control group (total 394)Number of events (recurrence, second primary cancer or death before recurrence) up to 15 March 2005
Summary
Clinical trial · Phase 3

Pembrolizumab for Early Triple-Negative Breast Cancer

N Engl J Med · 2020
64.8% vs 51.2%Pathological complete response
Summary
Clinical trial · Phase 3

Trastuzumab Emtansine for Residual Invasive HER2-Positive Breast Cancer

N Engl J Med · 2019
88.3% vs 77.0%3-year iDFS
Summary
Clinical trial

Adjuvant Capecitabine for Breast Cancer after Preoperative Chemotherapy

N Engl J Med · 2017
74.1% vs 67.6%Disease-free survival at 5 years (all patients)
Summary

Related links

Related cancer types

Breast cancer

Related questions

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References

20 references
Show all references, 9 with a study cardClose the reference list

Numbers in the text, such as [1], refer to these sources. Sources with a “Study card” button are summarised in the site’s evidence library.

  1. 1
    Chemotherapy to Treat CancerNational Cancer Institute · cancer.gov · 2025
    Source Back to text: 1 2
  2. 2
    Comparisons between different polychemotherapy regimens for early breast cancer: meta-analyses of long-term outcome among 100,000 women in 123 randomised trialsPeto R, Davies C, Godwin J, et al · Lancet · 2012;379:432-44
    Study cardDOIPubMed Back to text: 1 2 3 4 5
  3. 3
    Adjuvant Chemotherapy Guided by a 21-Gene Expression Assay in Breast CancerSparano JA, Gray RJ, Makower DF, et al · N Engl J Med · 2018;379:111-121
    Study cardDOIPubMed Back to text: 1 2 3 4 5 6 7
  4. 4
    TAILORx trial finds most women with early breast cancer do not benefit from chemotherapyNational Cancer Institute · cancer.gov · 2018
    Source Back to text: 1 2 3 4 5 6
  5. 5
    21-Gene Assay to Inform Chemotherapy Benefit in Node-Positive Breast CancerKalinsky K, Barlow WE, Gralow JR, et al · N Engl J Med · 2021;385:2336-2347
    DOIPubMed Back to text: 1 2 3 4 5 6 7
  6. 6
    70-Gene Signature as an Aid to Treatment Decisions in Early-Stage Breast CancerCardoso F, van't Veer LJ, Bogaerts J, et al · N Engl J Med · 2016;375:717-29
    DOIPubMed Back to text: 1 2 3
  7. 7
    70-gene signature as an aid for treatment decisions in early breast cancer: updated results of the phase 3 randomised MINDACT trial with an exploratory analysis by agePiccart M, van 't Veer LJ, Poncet C, et al · Lancet Oncol · 2021;22:476-488
    DOIPubMed Back to text: 1 2 3
  8. 8
    Biomarkers for Adjuvant Endocrine and Chemotherapy in Early-Stage Breast Cancer: ASCO Guideline UpdateAndre F, Ismaila N, Allison KH, et al · J Clin Oncol · 2022;40:1816-1837
    DOIPubMed Back to text: 1 2 3 4 5 6
  9. 9
    Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with early breast cancerPark KH, Loibl S, Sohn J, et al · ESMO Open · 2024;9:102974
    Study cardDOIPubMed Back to text: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
  10. 10
    Trastuzumab plus adjuvant chemotherapy for operable HER2-positive breast cancerRomond EH, Perez EA, Bryant J, et al · N Engl J Med · 2005;353:1673-84
    Study cardDOIPubMed Back to text: 1 2 3 4 5 6
  11. 11
    Seven-Year Follow-Up Analysis of Adjuvant Paclitaxel and Trastuzumab Trial for Node-Negative, Human Epidermal Growth Factor Receptor 2-Positive Breast CancerTolaney SM, Guo H, Pernas S, et al · J Clin Oncol · 2019;37:1868-1875
    DOIPubMed Back to text: 1 2 3
  12. 12
    Pembrolizumab for Early Triple-Negative Breast CancerSchmid P, Cortes J, Pusztai L, et al · N Engl J Med · 2020;382:810-821
    Study cardDOIPubMed Back to text: 1 2
  13. 13
    Overall Survival with Pembrolizumab in Early-Stage Triple-Negative Breast CancerSchmid P, Cortes J, Dent R, et al · N Engl J Med · 2024;391:1981-1991
    Study cardDOIPubMed Back to text: 1 2 3 4 5 6
  14. 14
    Relevance of breast cancer hormone receptors and other factors to the efficacy of adjuvant tamoxifen: patient-level meta-analysis of randomised trialsDavies C, Godwin J, Gray R, et al · Lancet · 2011;378:771-84
    Study cardDOIPubMed Back to text: 1 2 3 4
  15. 15
    Triple-negative breast cancer: clinical features and patterns of recurrenceDent R, Trudeau M, Pritchard KI, et al · Clin Cancer Res · 2007;13:4429-34
    DOIPubMed Back to text: 1 2
  16. 16
    Trastuzumab Emtansine for Residual Invasive HER2-Positive Breast Cancervon Minckwitz G, Huang CS, Mano MS, et al · N Engl J Med · 2019;380:617-628
    Study cardDOIPubMed Back to text: 1 2 3
  17. 17
    Adjuvant Capecitabine for Breast Cancer after Preoperative ChemotherapyMasuda N, Lee SJ, Ohtani S, et al · N Engl J Med · 2017;376:2147-2159
    Study cardDOIPubMed Back to text: 1 2 3
  18. 18
    Adjuvant chemotherapy in older women with early-stage breast cancerMuss HB, Berry DA, Cirrincione CT, et al · N Engl J Med · 2009;360:2055-65
    DOIPubMed Back to text: 1 2 3
  19. 19
    Clinical and Genomic Risk to Guide the Use of Adjuvant Therapy for Breast CancerSparano JA, Gray RJ, Ravdin PM, et al · N Engl J Med · 2019;380:2395-2405
    DOIPubMed Back to text
  20. 20
    US incidence of breast cancer subtypes defined by joint hormone receptor and HER2 statusHowlader N, Altekruse SF, Li CI, et al · J Natl Cancer Inst · 2014;106
    DOIPubMed Back to text

This page is based on reputable scientific sources and was last updated on 29 October 2026. The content of this website is for educational and informational purposes only and does not replace consultation, diagnosis or treatment by a specialist physician. Consult your treating physician about any treatment decision.

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