WHAT IS
NEOADJUVANT THERAPY?

What Is Neoadjuvant Therapy?

Neoadjuvant therapy really refers to therapy that is given before surgery. Traditionally in breast cancer, therapy has been mostly what we call adjuvant therapy – a therapy that you give after breast cancer surgery and therapy that is designed to reduce the chance of any future problems from breast cancer, and it’s usually post-operative. Neoadjuvant therapy refers to giving therapy before the surgery, so it’s a timing issue in relation to the tumour surgery, the cancer surgery.

Why Would You Have Neoadjuvant Therapy?

There are actually quite a large number of potential reasons why you might consider neoadjuvant therapy. Traditionally, we mostly considered neoadjuvant therapy when a patient had a very large breast cancer and perhaps one that wasn’t considered operable. The idea of the neoadjuvant therapy was to try to shrink the tumour and to make it operable. This can also be used when somebody has a large tumour that is operable, but we aim the neoadjuvant therapy to try to shrink the tumour before surgery with the aim of being able to perform a smaller surgery than would have been done if they had had their therapy after the surgery. In that instance, it might be possible to conserve the breast of a patient with a larger tumour by shrinking the tumour before the surgery.

Other reasons that you might consider neoadjuvant therapy is that generally this therapy will last for several months before the surgery and it provides a window of opportunity, of time, during which other things can happen. For example, some women would be referred for genetic assessment based on their family history or their age or their type of breast cancer, so it allows time for somebody to undergo genetic assessment, genetic counselling, and to receive results of genetic testing which might influence the type of breast cancer that they would want. It also allows women, if they’re making a decision in a short period of time, as to what kind of surgery they want. Often it’s at a time of high anxiety, so it allows women time to actually contemplate the type of surgery that they want over a period of time and with some of the initial anxiety diffused so that women can think about the type of surgery – whether they want to conserve the breast, whether they want a mastectomy, whether they would want to have bilateral mastectomy vs a unilateral or one-sided mastectomy. So it allows women time to think about the type of surgery they want. If somebody was going to undergo a mastectomy, it would allow time to plan a reconstruction.

The other really important thing about neoadjuvant therapy is if we give drugs to a patient with a breast cancer while the breast cancer remains in the breast, we can actually tell whether the drugs are helping by assessing whether that tumour is shrinking. So it actually gives you a method of assessing whether the drugs are helping. Most women actually receive their breast cancer drug therapy post-operatively when the cancer has gone, and in that scenario, we can’t actually tell whether the drugs are helping. We give drugs that we hope will help based on past experience but we can’t measure whether it’s helping, whereas if we give drugs pre-operatively, we can see by the change in the size of the tumour or the nature of the tumour or biopsies whether we feel we’re making an impact. So it gives us a way of assessing that.

Breast Cancer Trials developed the Neoadjuvant Patient Decision Aid to help women make an informed decision about their treatment. It is recommended for women who have recently been diagnosed with early-stage breast cancer. Find out more about this resource here.

Neoadjuvant Therapy in Breast Cancer Clinical Trials

Increasingly, neoadjuvant therapy is being employed in clinical trials in research for breast cancer because it’s a very useful way for us to identify new approaches to therapy because we can see while the cancer is there, and we can obtain biopsies that can tell us what changes are happening in a tumour, so it’s a routine part of therapy. The other thing is that with a neoadjuvant approach, it does actually provide more prognostic information for the women or the patients with breast cancer because particularly in the case of breast cancer that’s called ‘triple negative’ where there are no hormone receptors and HER2-negative. For cancers that are called HER2-positive, if the cancer completely goes away and there’s no evidence of cancer after the neoadjuvant therapy, that is quite powerful information that suggests that patient will have a better prognosis than a woman who has that same therapy and has significant tumour remaining. So, neoadjuvant therapy can provide prognostic information which is useful.

We’ve been conducting a clinical trial testing neoadjuvant therapy, and it’s one that I’ve been involved in called the ELIMINATE trial. In the ELIMINATE trial we’ve been looking at women who have a breast cancer which is larger than average, and one that is also considered to be hormone receptor positive or oestrogen receptor positive. Traditionally, these cancers will have surgery, then chemotherapy, then hormonal therapy. In the ELIMINATE trial, we’re giving the drug therapy prior to the surgery, and we are also looking at the question of whether giving chemotherapy at the same time as hormonal therapy might give a better initial shrinkage of the cancer, versus the usual sequential approach of chemotherapy before the surgery and then the hormonal therapy later.