FAQs

Yes. We work with two dedicated patient advocates who were involved with the study from the very beginning. They have been critical in ensuring the study is patient and women centered, throughout the study.

We are also working closely with the Independent Cancer Patients’ Voice (ICPV) charity and NIHR Research Champions to ensure the interests of women are represented at all times. Women with direct experience of breast cancer have also helped write our information sheet and trial video.

There are many types of breast cancer. The most common type is called oestrogen receptor-positive (ER+) breast cancer.

This type of cancer is ‘hormone dependent’. This means that the tumour has oestrogen receptors and the hormone oestrogen is required for it to survive and grow. This means we can target this dependence of hormones with endocrine therapy to treat the cancer.

Oestrogen is a female hormone produced by the ovaries as a normal part of the menstrual cycle before the menopause. It is important for normal female growth, development and hormone and reproductive cycles.

As part of the menopause the ovaries stop producing oestrogen, and due to this oestrogen levels drop after the menopause.

Endocrine therapy is also known as hormone therapy. Unlike hormone replacement therapy (also known as HRT) however, which provides additional hormones, endocrine therapy for breast cancer blocks or prevents the production of these hormones, so has the opposite effect to HRT.

There are several different types of endocrine therapy used to treat and prevent breast cancer.

One of the most common types of endocrine therapy used are tablets known as aromatase inhibitors (AIs).

Despite the drop in oestrogen levels at the menopause, small amounts of oestrogen continue to be produced in other parts of the body, by changing other hormones (androgens) into oestrogens.

The body does this using an enzyme called aromatase. This enzyme can be blocked using aromatase inhibitor (AI) medication. Blocking this enzyme therefore blocks the production of oestrogens.

The most widely used types of AI medication are letrozole, anastrozole and exemestane. Hundreds of thousands of women affected by breast cancer take this treatment every day.

ER+ breast cancers rely on oestrogen to grow and survive. Taking endocrine therapy with an aromatase inhibitor stops the body making oestrogen.

This starves the tumour of this hormone. This is why endocrine therapy with an aromatase inhibitor is very effective at both treating and preventing ER+ breast cancer.

It can also help ER+ breast cancers to shrink by stopping the ‘fuel’ that ER+ breast cancers use to grow. This is why we are using it in this study.

The study is trying to find out if a ‘tumour shrinking’ period with an endocrine therapy aromatase inhibitor, to treat the breast cancer before surgery, leads to a smaller operation and better recovery.

The treatment can be broken down into two periods. The first is a period of endocrine therapy before surgery known as “neo-adjuvant endocrine therapy” if used, this is to shrink the cancer before surgery. The second is a period of endocrine therapy after surgery (known as “adjuvant endocrine therapy”), which usually lasts for 5 or 10 years and is used to reduce the risk of the cancer from coming back.

This diagram may help explain this:

Yes - if you have been recently diagnosed with strongly ER+ breast cancer and your doctor has confirmed that the study treatments are suitable for you and:

• You have been through the menopause;
• You have hormone-sensitive breast cancer which is strongly ER+ on tests;
• The cancer is visible on ultrasound;
• The tumour measures 15 mm or larger;
• You have not started or are planned for chemotherapy and/or anti-HER-2 therapy.

There are different types of breast surgery, and your surgeon will explain your options to you.  There are many factors to consider for the type of surgery you will have. This includes the type and the size of the tumour, your general health and your preferences.

Tumour size

Generally, the larger the tumour, the more tissue that needs to be removed. This can mean a greater impact of the surgery on your body image and wellbeing.

Larger tumours are more likely to need more extensive surgery to remove them (mastectomy), or more tissue rearrangement at surgery to compensate for any defect (oncoplastic surgery).

Smaller tumours may be removed with less extensive or complex surgery (lumpectomy or breast conserving surgery).

Mastectomy or larger lumpectomy

More extensive or complex surgery involves the removal of more tissue and/or the entire breast and/or may lead to the need for further reconstruction. This in turn might lead to a longer recovery time.

This can affect your ability to get back to a normal life.

Breast-conserving surgery (‘lumpectomy’)   

The main advantage of avoiding a mastectomy (by shrinking the tumour so a lumpectomy is possible) or having a smaller lumpectomy is that it can preserve more of the appearance and sensation of your natural breast.

It is also less extensive, so you may have less scarring and an easier recovery.

Many people are recommended radiotherapy after a lumpectomy.

If you agree to participate in the study, you will be started on treatment with endocrine therapy immediately.

People may feel that breast cancer should be removed by surgery as soon as possible. However, we now know that this may not always be the best strategy, and surgery is one treatment amongst several others.

There are already known benefits to starting other treatments before surgery in particular circumstances. This may allow us to reduce the tumour size before surgery, assess the response to other treatments, and gives us more time to plan the surgery.

Yes, for some types of breast cancer that require chemotherapy, it is best given before surgery. Some types of cancer, other than breast cancer, can also be treated successfully without the need for surgery at all.

This study is to understand if for women that need endocrine therapy, but not chemotherapy, giving a slightly longer period of endocrine therapy before surgery is of benefit.

Treating the cancer with endocrine therapy before surgery is safe. It is recommended as an approach to consider in national and international health care guidelines.

Your endocrine therapy treatment starts the day you join the study and your tumour will be monitored closely both at the hospital and with scans.

Endocrine therapy is very effective for oestrogen sensitive breast cancer. You would also not be offered this research if we did not think the treatment options were good and safe.

However, during the close monitoring, the clinical team will always be able to schedule your surgery early if medically required.  

Taking endocrine therapy before surgery may reduce the number of repeat operations. This would also benefit women with smaller tumours.

It may also mean that less tissue needs to be removed allowing for a better cosmetic result, or that more complex oncoplastic (breast tissue rearrangement) surgery is not needed.

Mammograms and scans help us estimate the tumour size before surgery. We won’t know the exact size of the tumour until it is removed at your operation and analysed under a microscope.

We know that further operations are needed in around 1 in 5 (or 20% of) women who have a lumpectomy. This is because cancer was very close to the edge (or “margin”) of tissue removed at the first operation.

This often happens when the tumour ends up being larger under the microscope than expected from mammograms or ultrasound.

Being in this trial does not stop you accessing the right treatments for you. Remember - you will be recommended endocrine therapy and surgery as part of your usual treatment even if you do not take part in the EndoNET trial.

If you are unable to tolerate the side effects of your endocrine therapy, your clinical team will suggest changing it. For example, if you do not tolerate letrozole, you may be able to have anastrozole instead.

You should take a little time to think about the options. You can also discuss them with your partner, friends, family or GP.

Over the years improvements in treatments and outcomes have been driven by patients who participate in research, and those treated in research active centres often have better outcomes. Within the EndoNET trial you will be followed up by a dedicated research team in addition to your usual clinical team.