So I’ve completed my breast cancer triathlon, but it’s not the end of the journey. My breast cancer is sensitive to oestrogen. This means that the oestrogen I produce could stimulate any remaining cancer cells to grow and spread. It was time for Operation ‘Lose the Oestrogen’. I’ve been trying to tie this in with the triathlon analogy. The only thing I can think of is to liken it to the strength and conditioning workouts we all know we should be doing, but never get round to.

Classically this treatment starts after radiotherapy. The theory is that you want any remaining breast cancer cells to be active, so radiotherapy is more likely to destroy them. If you take oestrogen out of the equation, those cancer cells will be inactive and therefore less likely to be affected by radiotherapy.

In my case, I had to wait over 3 months before I could have radiotherapy, whereas most women only wait 4-6 weeks. If you remember, this was because I was waiting for my nipple to fall off, and I had to get my arm above my head. My oncologist decided she would rather start the anti-oestrogen therapy beforehand, because lobular cancer really only responds to the hormonal manipulation, and the chemotherapy hadn’t touched it. We didn’t want to risk any cells growing whilst I waited for radiotherapy to begin.

Who needs hormones?
The mainstay of treatment for any woman with an ER+ (American spelling of (o)estrogen, sorry) cancer is a daily tablet to reduce her oestrogen levels. If you are post-menopausal, your ovaries have stopped working but you still make a little oestrogen in your body fat via the enzyme Aromatase . There are 3 tablets that stop the Aromatase enzyme working, called, not surprisingly, Aromatase Inhibitors (AIs). They are Anastrozole (Arimidex), Letrozole (Femara) and Exemestane (Aromasin).

If you are pre-menopausal, your ovaries produce oestrogen, so you are given Tamoxifen instead. This works by stopping oestrogen attaching to breast cancer cells.

Some young women are also advised to switch off their ovaries with a monthly injection of Zoladex, on top of either Tamoxifen or an AI.

Action plan
My oncologist wanted me to take Tamoxifen for 10 years, based on the ATLAS trial data. On top of that, she wanted me to have Zoladex injections for 5 years. The standard used to be 2 years’ of injections, but data coming from several trials (TEXT and SOFT trials) has shown a benefit for longer treatment.

Time to put breast cancer behind you
This is easier said than done, because of the hormonal manipulation. Every day for the next 10 years I will take a tablet that could potentially make me feel rotten, in order to reduce the risk of the breast cancer coming back.

Every month for the next 5 years I will have to make an appointment with a nurse to get a possibly painful injection into my tummy, that could also make me feel rotten, in order to reduce the risk of the breast cancer coming back.

What both of these do is send you into an instant chemical menopause, with some or all of the side effects that happen when you stop producing oestrogen. No gentle warning signals. And you can’t take HRT to help, because that would be giving you oestrogen, which we’re trying to remove.

Panic stations
The one thing most of my patients complain about is the side effects of these tablets. Some don’t take the tablets, even though they know the tablets will reduce the risk of their breast cancer coming back, because their quality of life on the tablets is so poor.

I was really, really worried about starting this part of my treatment. I spent hours reading forums looking for the holy grail – but there isn’t one. You either get the side effects, or you don’t. Some women get a few, others get all of them. A bit like our mums going through the menopause – some had a horrific time and others sailed through.

I did read that symptoms generally get better in 6 months as the body gets used to the lack of oestrogen. I also read that switching the brand of Tamoxifen can make a difference (for example, Gordon’s gin versus Bombay Sapphire – both gin but taste different).

Side Effects
Here are links to the side effect profiles of the drugs:-

The common side effects are:
Hot flushes
Night sweats
Headaches and nausea
Weight gain
Vaginal dryness and painful sex
Loss of libido
Mood swings and altered concentration
Osteoporosis (bone thinning)

There is also a small but serious risk of getting a blood clot in your leg (DVT) or endometrial cancer

It was time to find out what was in store for me…