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Chemotherapy for Early Breast Cancer

Chemotherapy is a type of medicine which attacks fast-growing cells in your body including cancer cells. In early breast cancer, chemotherapy aims to cure the disease by killing any undetectable cancer cells that have escaped the breast and lymph nodes.

 
 

How is chemotherapy used in early breast cancer?

Chemotherapy is usually given intravenously via a cannula (drip) inserted into a vein in the hand or forearm. A course of chemotherapy for early breast cancer will take between 3-6 months depending on the type and combination of drugs used.

Chemotherapy is usually required to manage triple negative breast cancers and HER2 positive breast cancers and some faster-growing hormone receptor positive/HER2 negative cancers. Slower-growing hormone receptor positive/HER2 negative breast cancers usually do not benefit from chemotherapy treatment.

Neoadjuvant chemotherapy

In the past, chemotherapy was mostly given after surgery as part of treatment for breast cancer. This is termed 'adjuvant' chemotherapy. While adjuvant chemotherapy is still common, today chemotherapy may also be used prior to breast surgery as a means of shrinking the cancer and killing any cancer cells beyond the breast and lymph nodes. When chemotherapy is given prior to surgery it is termed 'neoadjuvant' chemotherapy.

Benefits of neoadjuvant chemotherapy

The effectiveness of chemotherapy (in terms of improving overall survival in breast cancer) is the same whether you have it before or after surgery. However, neoadjuvant treatment provides some additional benefits. These include:

Downstaging

Shrinking cancers can make them easier to remove surgically. Neoadjuvant therapy can reduce the size of the cancer in some patients, which may be especially useful for tumours considered inoperable at diagnosis, or large cancers where a mastectomy would be required if surgery was performed upfront. Around 25 out of every 100 patients treated with neoadjuvant systemic treatment (who would have required mastectomy upfront) will be able to avoid a mastectomy.

Prognostication

There is good data showing that the better a cancer responds to systemic treatment, then the lower the chances that the cancer will recur. If surgery is performed first, there is no opportunity to assess this response because the cancer has already been removed. Giving systemic treatment first allows medical teams to assess how the cancer responds to medicines, which can provide useful information about the chance of the cancer coming back in the future.  

Treatment planning post surgery

How a person responds to systemic treatment given prior to surgery is increasingly being used to guide how treatment is managed after surgery to improve outcomes. This may include being prescribed additional chemotherapy after surgery for people with triple negative breast cancers (often in tablet form) or changing the targeted therapy used after surgery for HER2 positive breast cancers depending on the response demonstrated at surgery.

Improved surgical planning

Where a person is likely to need a mastectomy, giving neoadjuvant systemic treatment allows for more time to consider options for breast reconstruction if this is desired.  

For more information about the benefits of neoadjuvant systemic therapy some excellent resources include:  

Adjuvant chemotherapy

For some types of breast cancer, surgery is used as the first mode of treatment as it allows for more information to guide subsequent treatment such as radiotherapy, chemotherapy and hormonal therapy. When chemotherapy is used after surgery as part of treatment for breast cancer, it is termed 'adjuvant' chemotherapy.

Whilst most people with HER-2 positive and triple negative cancers are recommended to have neoadjuvant systemic therapy, people with very small cancers may still be recommended to have surgery first. This allows medical teams to better understand the need, type and amount of systemic treatment required.

For people with hormone receptor positive/HER-2 negative cancers, sometimes the need for chemotherapy is not clear-cut. By removing the cancer, pathologists can examine it whole (as opposed to a small sample taken at a biopsy), which can better inform medical oncologists about the need for subsequent chemotherapy.

Sometimes further tests may be recommended to clarify the biology of hormone receptor positive/HER-2 negative cancers (in order to predict the benefits of adjuvant chemotherapy). These can be performed on the surgical specimen from your breast surgery. Examples of these ‘gene-profiling’ tests include OncotypeDx, Prosigna and EndoPredict. These tests are not useful in all circumstances. They are also expensive and not funded by Medicare or private health insurers.

Common chemotherapy treatment combinations

How do we work out which treatment combinations (or 'regimens') for breast cancer are recommended for different people? These decisions are always based on a person’s individual circumstances, the breast cancer subtype and characteristics of the cancer pathology. Some overall guidelines are as follows:

  • Most treatment regimens include two or more different chemotherapy drugs, in addition to targeted therapies such as trastuzumab (Herceptin) if indicated.

  • The most common chemotherapies used for the treatment of early breast cancer are taxanes (including docetaxel and paclitaxel), anthracyclines (including doxorubicin and epirubicin) and cyclophosphamide.

  • When trastuzumab is required (for HER2 positive cancers), this is administered in combination with chemotherapy, and then continues on its own after the completion of chemotherapy, to complete a total of 12 months of treatment.

  • Another targeted therapy called pertuzumab (Perjeta) may also be recommended in combination with Herceptin and neoadjuvant chemotherapy, to improve the chances of the cancer disappearing completely prior to surgery.

If you have any specific questions or concerns about your treatment regimen, speak to Dr Ben Forster.

Read more about managing side effects of chemotherapy.

Chemotherapy for Her2 negative breast cancers

The choice of chemotherapy regimen depends on the risk of recurrence in the future, and discussion around the potential risks and benefits of the treatment for each patient. Commonly prescribed regimens include:

  • TC (docetaxel and cyclophosphamide, given every three weeks for four cycles) given usually in the adjuvant setting

  • AC (doxorubicin and cyclophosphamide, given every 2-3 weeks for four cycles) given usually in the adjuvant setting

  • AC-T (doxorubicin and cyclophosphamide, given every 2-3 weeks for four cycles, followed by paclitaxel given weekly for 12 cycles) given in the adjuvant or neoadjuvant setting

  • EC-D (epirubicin and cyclophosphamide, given every three weeks for three cycles, followed by docetaxel given every three weeks for three cycles) given in the adjuvant or neoadjuvant setting

Her2 positive breast cancer chemotherapy

Her2 positive breast cancer requires regimens that include chemotherapy in combination with trastuzumab (Herceptin). Examples of these are outlined below:

  • AC-TH (doxorubicin and cyclophosphamide, given every 2-3 weeks for four cycles, followed by paclitaxel given weekly for twelve cycles and trastuzumab given every three weeks for 12 months) given in the adjuvant or neoadjuvant setting

  • TCH (docetaxel and carboplatin, given every three weeks for six cycles, in combination with trastuzumab given every three weeks for 12 months) given in the adjuvant or neoadjuvant setting

  • Paclitaxel/trastuzumab (paclitaxel given weekly for twelve cycles and trastuzumab given every three weeks for 12 months) given in the adjuvant setting

N.B pertuzumab (Perjeta), may also be given in some circumstances in combination with trastuzumab (Herceptin) in neoadjuvant regimens for HER-2 positive cancer.

If chemotherapy and targeted therapy are used in the neoadjuvant setting for Her2 positive breast cancer and there is evidence of an incomplete response (i.e. residual disease at the time of surgery), then trastuzumab is usually switched to TDM1/trastuzumab emtansine (Kadcyla) after surgery.

 

Dr Forster will discuss the specific details of the recommended chemotherapy schedule with at the time of your appointment, including the potentials risks and adverse effects of treatment.