Breast Cancer - the results of the Onchotype DX test and hormone therapy

This post follows my initial post about Sewing a gown for breast cancer surgery

and my previous post talking about Appointments to decide about chemotherapy and radiation treatment

Please note that this is my personal medical story. There are details of medical procedures. I am not a medical doctor. 

Onchotype DX Results

When I last posted an update I was waiting to hear about the results of the Onchotype DX test which is a genomic test, performed on a sample of my tumour, that determines whether chemotherapy will be beneficial in my case. 

I am absolutely thrilled to report that the test results showed that the benefit of chemotherapy would be less than 1% so it is not recommended for me!

My Onchotype DXtest results

What does this mean?

The Onchotype DX test looks at the genes in the tumour and how they influence the way the tumour grows and spreads. The test can also determine how likely it is that the tumour will respond to chemotherapy and how likely it is that the cancer will return. Most patients with early-stage breast cancer that isn't in the lymph nodes (like mine) will not benefit from chemotherapy, but some patients will. As I mentioned previously, I decided it was worth spending $5000 to find out whether I was in the minority that should have chemo, or could I avoid it?

The first result, reading from left to right above, is the Recurrence Score. Mine was 13, which is under 25 and therefore considered a low score. This means that there is only a small chance that the cancer will return and therefore chemotherapy is likely to be of little benefit. It is not definite that the cancer won't return, but very unlikely. 

The estimated likelihood of recurrence after 9 years is 4% (second result). However, that is assuming that I have 'AI or TAM', which are abbreviations for the oestrogen blocking medications 'Aromatase Inhibitors' and 'Tamoxifen'. This hormone therapy is considered essential in my case to reduce the chance of the cancer returning.

The third result gives the estimated benefit of chemotherapy, which is less than 1% in my case.

Underneath the main results is a table that shows the benefit of chemo, based on recurrence score for patients over and under 50 years old. Fortunately, my score of 13 shows a <1% benefit for patients above and below 50 years. For patients under 50 years, the benefit of chemo increases slightly to 1.6% with a recurrence score of 16, but the over 50 age group only benefits from chemo if they have a recurrence score above 25.

I can officially say that I don't need chemo. Hooray!

Hormone Therapy

So now I'm on to the next phase of treatment, which is hormone therapy or, more specifically, hormone blocking medication to stop the body producing oestrogen. The reason for this is that the type of cancer I have 'feeds' on oestrogen. There are various types of hormone therapy, the most well known being Tamoxifen, and the oncologist decides which is most suitable for each individual patient. In my case I'm having two different medications which I will have to take for five years. 

My oncologist wants me to take Exemestane (Aromasin), which is an oestrogen blocker recommended for patients who have been through menopause. I have not yet been through menopause, so I will have to take a second medication called Zoladex (Goserelin) which will put me into medically-induced menopause by stopping the ovaries from producing oestrogen. This one may not be necessary for the full five years if I go into actual menopause during that time. I think this can be determined by a blood test. The Zoladex is in the form of an injection, which I have to have monthly, so it's back to hospital for that.

On the day of the appointment for my first injection I had to go into the chemotherapy ward of the hospital. Under current guidelines, anyone entering the Oncology Department has to have a Rapid Antigen Test (RAT) for Covid beforehand as patients having chemo are likely to be immunocompromised, so at high risk of infection. This means arriving at the hospital an hour before the appointment to complete the RAT. Once in to Oncology, I was led past the patients receiving chemo. It was very quiet and calm in there. 

The Zoladex injection consists of a small pellet that is injected into the tummy. The needle is large, but I didn't look so I can't tell you how large! There was a bit of to-ing and fro-ing as the nurse tried to find a good place for the injection. The skin on my tummy is still pretty tight from the surgery, so that was a problem. Eventually she was able to pinch a bit at the side towards my hip. The process was a bit painful, but over very quickly. I was given some numbing cream to put on for next time.

I was also given my first box of Exemestane tablets which I have to take daily.

Both medications can have similar side effects, which are commonly the symptoms of menopause, but can also include joint and bone pain and osteoporosis, amongst other things. Due to the risk of osteoporosis I will need to go for bone density scans periodically throughout the treatment and may need bone infusions to prevent the bones from thinning. There is a really good website discussing hormone therapy and many other aspects of breast cancer here.

I have now been on the two hormone blocking medications for just under three weeks and so far I haven't noticed any side effects, apart from maybe some tiredness and mild muscle aches. I know that exercising really helps with the side effects and I have kept up the walking, as well as doing twice weekly sessions in the gym with an oncology physiotherapist. The gym sessions are fantastic and are covered under Medicare. I have a personalised programme to help me get back my range of movement after the surgery and also some weight-bearing exercises to help prevent osteoporosis. Alcohol can also exacerbate side effects, so I'm keeping that to a minimum.

So overall things are really good. I feel like I'm getting back to normal, albeit a new kind of normal, and that the worst of this is now behind me. I even went on a trip away, which I haven't done for a very, very long time, as my parents very kindly paid for a trip to Rottnest Island. Here I am with a friendly quokka!