Do all patients receive chemotherapy?

No. About 30 to 50% of patients undergoing breast cancer surgery receive chemotherapy. The decision depends on the molecular subtype, stage, genomic signatures and the multidisciplinary team meeting.

What is the difference between neoadjuvant and adjuvant chemotherapy?

Neoadjuvant: before surgery, to shrink the tumour, assess pathological complete response (pCR) and de-escalate axillary surgery. Adjuvant: after surgery, to eradicate residual micrometastases and reduce recurrence risk.

How long does breast cancer chemotherapy last?

Generally 4 to 6 months, sometimes followed by one year of trastuzumab for HER2+ tumours or 1 to 3 years of capecitabine, T-DM1, olaparib or abemaciclib depending on the profile.

It depends on the protocol used, not on chemotherapy in general. Anthracyclines (EC, AC, FEC) and taxanes (docetaxel, paclitaxel) cause hair loss in over 95% of cases, starting 2-3 weeks after the first cycle. With anti-HER2 alone (trastuzumab, pertuzumab), hormone therapy, or targeted treatments (abemaciclib, olaparib), there is no or very little hair loss. Scalp cooling limits hair loss and is most effective with anthracycline-free protocols (TOLANEY, TC, TCHP).

Does chemotherapy affect fertility?

Yes, particularly anthracyclines and cyclophosphamide. An oncofertility consultation must be offered before treatment for women under 40: oocyte cryopreservation, ovarian suppression with LH-RH agonists during chemotherapy.

Can a genomic test avoid chemotherapy?

Yes. For HR+/HER2- N0 (and selected N1) breast cancers, OncotypeDX, MammaPrint, EndoPredict and Prosigna signatures avoid chemotherapy in 60 to 70% of patients with a low score, without loss of chance (TAILORx, MINDACT trials).

Who prescribes and monitors chemotherapy?

The medical oncologist. Dr Zeitoun, breast surgeon, coordinates the pathway with the medical oncologist, the pathologist, the radiation oncologist and the radiologist within the multidisciplinary team meeting.

Breast cancer chemotherapy in Paris

Q: What are the most common chemotherapy protocols?

Main protocols: EC-T or AC-T (anthracycline then taxane, 4-6 months) for triple-negative and high-risk HR+/HER2- cancers; TCHP (taxane + carboplatin + trastuzumab + pertuzumab) for HER2+ ≥2 cm; TOLANEY protocol (weekly paclitaxel + trastuzumab) for small node-negative HER2+ cancers; KEYNOTE-522 (chemo + pembrolizumab) for triple-negative ≥2 cm or node-positive; TC (docetaxel + cyclophosphamide) as an anthracycline-sparing alternative.

Q: What is the TOLANEY protocol?

A de-escalated chemotherapy protocol validated for small HER2-positive node-negative tumours (≤3 cm). It combines weekly paclitaxel for 12 weeks + trastuzumab for 1 year, without anthracyclines or carboplatin. Better tolerated: less fatigue, less neutropenia, no anthracycline cardiotoxicity. Validated by the APT trial (Tolaney et al., 2015 and 2019).

KEY POINTS

In 30 seconds

Chemotherapy is an intravenous treatment that works throughout the whole body — whereas surgery only treats the breast. Its job is to destroy any cancer cells that may have escaped.
Not every patient needs it. Most low-risk hormone-positive cancers are treated without chemotherapy. A genomic test can confirm this.
It is almost always recommended for triple-negative and HER2-positive cancers, where it clearly improves outcomes.
It lasts about 4 to 6 months, with one infusion every 2 or 3 weeks. It can be given before or after surgery depending on the case.
Side effects (fatigue, hair loss, nausea) are usually reversible and far better controlled today than they were 20 years ago.

KEY FIGURES

A few useful reference points

The orders of magnitude worth knowing.

1 in 3 patients

receives chemotherapy after breast cancer surgery. The other two do not need it.

2 in 3 patients

can avoid chemotherapy thanks to a genomic test, when their cancer is hormone-positive and intermediate-risk.

4 to 6 months

is the typical treatment duration, with one infusion every 2 or 3 weeks.

2 to 4 hours

is the length of one infusion in day hospital. You go home afterwards.

3 to 5 days

after each infusion is when fatigue is most marked. Then it eases.

Understand

What does chemotherapy actually do?

When a breast cancer is operated on, the tumour is removed. But one question remains: could some cancer cells have detached before surgery and travelled elsewhere in the body? Often we cannot see them — they are far too small to show on any imaging. That is precisely the role of chemotherapy: to track down those potentially scattered cells, wherever they may be.

Diagram: how breast cancer chemotherapy works

Chemotherapy circulates throughout the body and targets cancer cells wherever they may be.

Surgery is a local treatment: it acts only on the breast and the armpit. Chemotherapy, by contrast, is a whole-body (or "systemic") treatment: the drugs travel through the blood and reach everywhere. That is its strength — but also why it has more side effects: it does not target only cancer cells, it also affects healthy cells that divide rapidly (hair, mucous membranes, blood).

Chemotherapy drugs have evolved enormously. Alongside the "classic" molecules (taxanes, anthracyclines), there are now much more targeted treatments: immunotherapy (which helps your immune system recognise the cancer), anti-HER2 therapies (which block a specific protein), and others. The word "chemotherapy" often refers to all these whole-body treatments together, even though technically each works in a different way.

Timing

Before or after surgery?

The decision is made at the multidisciplinary team meeting (MDT).

Both options exist, and the choice is not trivial. Here is what each one really means:

Before surgery

Neoadjuvant chemotherapy

Medical treatment first, then surgery. Five concrete benefits:

The tumour can shrink, sometimes enough to switch from a mastectomy to a lumpectomy
It shows the in vivo response to treatment: if the tumour melts, that is reassuring; if it resists, treatment can be adjusted (I-SPY, KATHERINE trials)
A pathological complete response (pCR: no remaining cancer cells in the surgical specimen) predicts excellent long-term survival — especially in triple-negative and HER2+ disease
Major survival benefit for HER2+ and triple-negative cancers ≥ 2 cm or node-positive. It is in these subtypes that starting with neoadjuvant treatment has shown the greatest impact on event-free survival
It allows time for genetic counselling and oncofertility: the 4-6 months of treatment leave room to test for a BRCA mutation, which can change surgical strategy itself (bilateral prophylactic mastectomy discussed if BRCA1/2)

Preferred for HER2+ and triple-negative cancers ≥ 2 cm or with positive nodes.

After surgery

Adjuvant chemotherapy

Surgery first, then medical treatment. Main reasons:

When the full diagnosis (true size, nodes, subtype) is only known after surgery
For hormone-positive cancers at intermediate or high risk
When uncertainty remains and a genomic test on the surgical specimen will guide the decision
For small (< 2 cm), unifocal, favourable-profile tumours where the benefit of neoadjuvant treatment is not established

The historical strategy for many hormone-positive low or intermediate-risk cancers.

Key trials

The trials that shaped current neoadjuvant practice.

KEYNOTE-522

Schmid et al., N Engl J Med 2020 (update 2022)

Adding pembrolizumab to neoadjuvant chemotherapy increases pathological complete response from 51% to 65% in early triple-negative disease and improves event-free survival.

NeoSphere

Gianni et al., Lancet Oncol 2012 (follow-up 2016)

Trastuzumab + pertuzumab + docetaxel achieves 45% pathological complete response in HER2+ disease, versus 29% with trastuzumab alone.

KATHERINE

von Minckwitz et al., N Engl J Med 2019

For HER2+ tumours with residual disease after neoadjuvant treatment, T-DM1 reduces recurrence risk by 50% compared with trastuzumab alone.

CTNeoBC

Cortazar et al., Lancet 2014 (meta-analysis)

Pathological complete response after neoadjuvant treatment is associated with significantly improved overall survival, most strongly in triple-negative and HER2+ subtypes.

BRCA & neoadjuvant

Tung et al., J Clin Oncol 2020; GeparOLA

BRCA status modifies surgical strategy. The 4-6 months of neoadjuvant treatment allow the oncogenetics consultation to be completed before definitive surgery.

The choice between the two sequences is made by the multidisciplinary team, with the surgeon, medical oncologist, radiation oncologist and pathologist, based on the pathology report.

For whom

Who is chemotherapy for?

The answer depends on the biological profile of your tumour, identified at biopsy. Each profile has its own logic.

A short glossary to get oriented

HR+ "hormone-positive"

The tumour has hormone receptors (oestrogen and/or progesterone) on its surface. It is "fed" by hormones. The most common profile (about 70% of breast cancers). Hormone therapy works very well on these cancers.

HER2+

The tumour produces large amounts of a protein called HER2 that drives rapid growth. Targeted anti-HER2 drugs (such as trastuzumab) block it very effectively.

Triple-negative

The tumour has neither hormone receptors nor HER2 ("negative" on all three). So neither hormone therapy nor anti-HER2 work. Chemotherapy is then the main treatment.

Triple-negative

Almost always

This subtype has neither hormone receptors nor HER2 — so neither hormone therapy nor anti-HER2 therapies work. Chemotherapy remains the cornerstone, and it is now often combined with immunotherapy (pembrolizumab) before surgery for tumours ≥2 cm or with positive nodes. The benefit is very clear.

HER2 positive

+ targeted therapy

The HER2 protein is overproduced by the cancer cells. We target it with specific antibodies (trastuzumab, pertuzumab) combined with chemotherapy. This subtype now has some of the best outcomes, whereas it used to be one of the most difficult. Anti-HER2 therapy continues for 1 year. For small HER2+ tumours (≤3 cm, node-negative), a de-escalated regimen exists: the TOLANEY protocol (weekly paclitaxel + trastuzumab), without anthracyclines, with better hair preservation.

HR+ / HER2− high risk

Depends on risk

Hormone-positive (HR+) without HER2 cancers with several positive nodes, high grade or large size may justify chemotherapy in addition to hormone therapy. For intermediate cases, a genomic test on the tumour is invaluable: it often safely allows chemotherapy to be avoided.

HR+ / HER2− low risk

No chemotherapy

Hormone-positive cancer with small tumour, negative nodes, low grade: chemotherapy brings no meaningful benefit. Hormone therapy alone (often 5 to 10 years) is enough. This is the most frequent situation — and that is good news.

Protocols

Chemotherapy protocols — and which ones cause hair loss

Each protocol is tailored to the biological subtype and stage.

A "protocol" means the specific combination of drugs used, the number of cycles and their schedule. Below are the most common ones in breast cancer, with their real-world impact on hair loss. This is often the first question asked — the answer depends mostly on the type of drugs used.

Anthracycline + taxane

EC-T / AC-T / FEC-T

The "classic" regimen: 3-4 cycles of EC (epirubicin + cyclophosphamide) or AC, then 3-4 cycles of a taxane (docetaxel or paclitaxel). Total duration: 4 to 6 months.

Hair loss: almost universal (>95%). Scalp cooling is possible but less effective with anthracyclines.

Used for: triple-negative, HR+/HER2− high risk, some HER2+.

Triple-negative neoadjuvant

KEYNOTE-522

For triple-negative cancers ≥2 cm or with positive nodes: chemotherapy (carboplatin + paclitaxel then EC or AC) + pembrolizumab (immunotherapy) before surgery, then pembrolizumab alone afterwards. Total duration: about 1 year.

Hair loss: almost universal. Immunotherapy does not worsen hair loss but adds other effects (thyroid, skin).

HER2+ standard

TCHP / TCH

For HER2+ cancers ≥2 cm or with positive nodes: taxane + carboplatin + trastuzumab + pertuzumab (TCHP) before surgery. Then trastuzumab (± pertuzumab) alone for the rest of the year.

Hair loss: almost universal (taxane). Scalp cooling is more effective here (no anthracyclines).

HER2+ small tumours

TOLANEY protocol

For small HER2+ tumours (≤3 cm, node-negative): weekly paclitaxel for 12 weeks + trastuzumab for 1 year. No anthracyclines, no carboplatin. Much better tolerated. Validated by the APT trial (Tolaney et al., 2015 and 2019).

Hair loss: common but often partial (paclitaxel alone). Scalp cooling considerably more effective.

HR+ post-menopausal

Docetaxel + cyclophosphamide (TC)

Alternative to anthracyclines for hormone-positive intermediate-risk cancers: 4 cycles of docetaxel + cyclophosphamide, every 3 weeks. Duration: 3 months.

Hair loss: almost universal but regrowth quicker (no anthracyclines).

Targeted therapies (no chemo)

Abemaciclib, olaparib, anti-HER2

Taken after chemotherapy or alone depending on the case: abemaciclib for 2 years for high-risk HR+ (MonarchE), olaparib for 1 year for BRCA mutation (OlympiA), trastuzumab alone for 1 year.

Hair loss: none or very rare. These are not chemotherapies in the strict sense.

The protocol is chosen by the multidisciplinary team based on your tumour profile, age, prior medical history (cardiac in particular), and the expected risk/benefit. Ask your oncologist: "Can I avoid anthracyclines?" — the answer depends on your tumour type, but it is worth asking.

Pathway

What does it actually look like, step by step?

Here is what a chemotherapy pathway typically looks like.

1

Consultation with the medical oncologist

The oncologist explains the chosen regimen, the planned number of cycles, the drugs involved and their expected effects. They will order a pre-treatment workup (blood tests, echocardiogram) and arrange the placement of a venous access device.
2

Placement of an implantable port

A small device placed under the skin, just below the collarbone, connected to a large vein. It avoids needle sticks in the arms at every cycle and protects the veins. Placement is quick (30 min, local anaesthetic) and the device stays in place for the whole treatment, sometimes longer.
3

If you wish to have children: fertility preservation consultation

A crucial and time-sensitive step if you are considering having children. Chemotherapy can affect fertility, especially after age 35. Egg or embryo freezing can be organised — but it takes 2 to 4 weeks. The decision must therefore be made before the first cycle.
4

Chemotherapy cycles

Frequency and duration vary by protocol:
- EC-T / AC-T: 3-4 cycles every 3 weeks + 3-4 cycles every 3 weeks (or 12 weekly paclitaxel). Total 4 to 6 months
- TCHP (HER2+): 6 cycles every 3 weeks before surgery. About 4-5 months, then trastuzumab alone to complete 1 year
- TOLANEY (small HER2+): weekly paclitaxel for 12 weeks + trastuzumab for 1 year. So 12 closely-spaced infusions
- TC (HR+ alternative): 4 cycles every 3 weeks. Total 3 months
- KEYNOTE-522 (triple-negative): 8 chemotherapy cycles over 5-6 months + pembrolizumab every 3 weeks for ~1 year total
Each infusion lasts 1 to 4 hours in day hospital. Before each cycle, a blood test confirms recovery. If white cells are too low, the cycle can be delayed a few days or supportive medication added.
5

Between cycles

Life carries on between infusions. Fatigue is most marked for 3-5 days after each cycle, then eases. Most patients maintain activity (family life, sometimes part-time work). You have a number to reach the team in case of fever, vomiting or concern.
6

Surgery (if neoadjuvant chemo)

A few weeks after the last cycle, surgery takes place: lumpectomy or mastectomy as decided, with assessment of the sentinel lymph node.
7

Further treatments

After chemotherapy, what often follows is radiotherapy (5 to 6 weeks), then hormone therapy (5 to 10 years for hormone-positive cancers), or continuation of targeted therapies (anti-HER2 for 1 year).

Side effects

What can happen, and what can be done

Side effects depend on the regimen, but here are the main ones and what helps. Most are manageable — and nearly all are reversible once treatment ends.

Fatigue

The most common effect. Peaks 3-5 days after each cycle. Eased by gentle physical activity (walking, gentle yoga), short naps and support at home.

Hair loss

Very common with taxanes and anthracyclines, starting around day 15-21. Scalp cooling (worn during infusion) significantly reduces hair loss. Regrowth starts 1 to 2 months after the last cycle.

Nausea

Far better controlled than before thanks to modern antiemetics. Given systematically, before and after the infusion. Severe forms are now quite rare.

Low white blood cells

Monitored by blood test before each cycle. If needed, an injection (G-CSF) stimulates the bone marrow. Simple hygiene: avoid crowds on low-count days, wash hands carefully.

Tingling in hands/feet

Linked mainly to taxanes (paclitaxel). Dose adjustments are possible, and cooling mittens/socks can be used during the infusion. Usually resolves after treatment ends.

Sensitive mouth

Dryness, small ulcers. Regular mouth rinses, lukewarm food, gentle brushing. Usually short-lived.

Effects on the heart

Systematic monitoring (echocardiogram) with anthracyclines and anti-HER2 drugs. Cardiac function usually recovers once treatment stops. Very rare with adequate monitoring.

Fertility

A real risk, especially after age 35. Fertility preservation consultation before starting. Options: egg/embryo freezing, ovarian protection medication during chemotherapy in selected cases.

Can it be avoided?

When chemotherapy can be avoided

This is one of the great advances of the past 15 years: for many hormone-positive breast cancers, we can now identify the patients who do not need chemotherapy, without taking any risk.

The tool: a test on the tumour itself (not on your blood) that measures the activity of certain genes. Four tests have been validated in France since 2023: Oncotype DX, MammaPrint, EndoPredict, Prosigna. They produce a score that distinguishes "active" tumours (which benefit from chemotherapy) from "lazy" ones (where hormone therapy alone is enough).

Based on the TAILORx and MINDACT trials, 60 to 70% of eligible patients avoid chemotherapy thanks to these tests, with no loss of survival. This has become the standard for HR+/HER2− cancers with 0 to 3 positive nodes, particularly in postmenopausal women.

→ Read more on genomic tests

Your questions

Frequently asked questions about chemotherapy

The questions patients most often ask — before treatment, during, or simply to understand what is being proposed. If yours isn't here, it will find its answer in consultation.

What is chemotherapy for?▾

It complements surgery by attacking any cancer cells that may have spread through the body but cannot be detected. Surgery treats the breast locally; chemotherapy treats the whole body.

Does every patient need chemotherapy?▾

No. Most low-risk hormone-positive breast cancers are treated without chemotherapy. For intermediate cases, a genomic test helps decide — it allows chemotherapy to be avoided in 60-70% of eligible cases.

Before or after surgery?▾

Both are possible. Before surgery ("neoadjuvant"), chemotherapy can shrink the tumour and show how it responds. After ("adjuvant"), it completes surgery. The choice is made in MDT based on the tumour profile.

How long does it last?▾

Typically 4 to 6 months, with one infusion every 2 or 3 weeks. Targeted therapies (anti-HER2, immunotherapy, hormone therapy) can then continue for 1 year or more.

Will I lose my hair?▾

It depends on the protocol used, not on chemotherapy in general. Anthracyclines (EC, AC, FEC) and taxanes (docetaxel, paclitaxel) cause hair loss in over 95% of cases. Hair loss starts 2-3 weeks after the first cycle. With anti-HER2 alone (trastuzumab, pertuzumab), with hormone therapy or with targeted treatments (abemaciclib, olaparib), there is no or very little hair loss. Scalp cooling, worn during infusion, limits hair loss — it is considerably more effective without anthracyclines (TOLANEY, TC, TCHP protocols).

What are the most common chemotherapy protocols?▾

Main protocols: EC-T / AC-T (anthracycline then taxane, 4-6 months) for triple-negative and high-risk HR+/HER2− cancers; TCHP (taxane + carboplatin + dual anti-HER2) for HER2+ ≥2 cm; TOLANEY protocol (weekly paclitaxel + trastuzumab) for small HER2+ without positive nodes, much better tolerated; KEYNOTE-522 (chemo + pembrolizumab immunotherapy) for triple-negative ≥2 cm or with positive nodes; TC (docetaxel + cyclophosphamide) as an anthracycline-sparing alternative for some HR+ cancers. The choice is made in MDT based on your tumour profile.

What is the TOLANEY protocol?▾

It is a de-escalated chemotherapy protocol validated for small HER2-positive tumours without nodal involvement (typically ≤3 cm). It combines paclitaxel given weekly for 12 weeks + trastuzumab for 1 year. No anthracyclines, no carboplatin. It is significantly better tolerated than the more intensive protocols: less fatigue, less drop in white cells, no anthracycline cardiotoxicity, and scalp cooling works well. It is named after Sara Tolaney who published the results (APT trial) in 2015 and 2019.

Can anthracyclines be avoided?▾

Yes in several situations: TC protocol (docetaxel + cyclophosphamide) for some intermediate-risk HR+/HER2−; TOLANEY or TH (paclitaxel + trastuzumab) protocols for small HER2+; no chemotherapy at all for low-risk HR+/HER2− thanks to genomic tests. Anthracyclines (EC, AC, doxorubicin, epirubicin) are effective but carry cardiac toxicity that we try to avoid when possible — particularly if you have any cardiac fragility. Ask your oncologist.

Can I have children afterwards?▾

Yes, but chemotherapy can affect fertility, especially after age 35. If you plan to have children, a fertility preservation consultation must take place BEFORE starting treatment, as soon as the diagnosis is made. Egg or embryo freezing is possible.

Is it covered by insurance?▾

Yes, 100% covered by French public health insurance under ALD 30 long-term illness coverage. No out-of-pocket cost on medications. Some additional fees may apply for sector-2 specialists.

Chemotherapy for breast cancer Dr Jérémie Zeitoun · Breast surgeon Paris

In 30 seconds

A few useful reference points

What does chemotherapy actually do?

Before or after surgery?

Neoadjuvant chemotherapy

Adjuvant chemotherapy

Who is chemotherapy for?

Chemotherapy protocols — and which ones cause hair loss

EC-T / AC-T / FEC-T

KEYNOTE-522

TCHP / TCH

TOLANEY protocol

Docetaxel + cyclophosphamide (TC)

Abemaciclib, olaparib, anti-HER2

What does it actually look like, step by step?

Consultation with the medical oncologist

Placement of an implantable port

If you wish to have children: fertility preservation consultation

Chemotherapy cycles

Between cycles

Surgery (if neoadjuvant chemo)

Further treatments

What can happen, and what can be done

Fatigue

Hair loss

Nausea

Low white blood cells

Tingling in hands/feet

Sensitive mouth

Effects on the heart

Fertility

When chemotherapy can be avoided

Related reading

A second opinion

Frequently asked questions about chemotherapy