Question asked by: 
Date asked: 
Jan 2016

My relative's stage IV epithelial ovarian cancer has recurred just over 12 months after she was treated with radical surgery, followed by chemotherapy with carboplatin, paclitaxel and bevacizumab. She is BRCA2 positive, and her cancer is oestrogen receptor positive.  The recurrent tumours are small - less than 1cm and she is asymptomatic. Instead of repeating her chemotherapy straight away, she has been started on anastrozole to reduce the oestrogen that may be helping the tumours to develop. I have two questions: 

1.     I am struggling to find the evidence for using anastrozole in epithelial ovarian cancer. I know a trial is underway. How effective is anastrozole as far as we know? 

2.    If the anastrozole works, will it shrink the tumours, or just prevent them growing further, and can it prevent further tumours forming elsewhere?

Do you have any more information on anastrozole?
Anastrozole works best in tumours that are strongly oestrogen receptor positive and doesn’t have too many side effects
Response by Professor Richard Edmondson, Professor of Gynaecological Oncology

As with all things in medicine there is often no absolutely right or wrong thing to do but most now agree that there is no rush to repeat chemotherapy if the tumours are small and not causing any symptoms. The idea of giving a drug at this point that could keep the disease under control for a bit longer is therefore very sensible. Anastrazole is a sensible option as it doesn't have too many side effects.

The question of course, as you point out, is whether it will work. The evidence we have from trials so far is that it works best in tumours that are strongly oestrogen receptor positive, not just a bit. If your relative's tumour has a lot of oestrogen receptor then this is a very sensible idea.  Response rates vary between studies, mainly because studies have included slightly different groups of patients but have been described as high as 35-45% in some studies. About half of those who respond seem to get a reduction in the size of the tumour whilst the tumour stays static in the other half.
There is another trial which has just completed and will be published later this year but I haven't seen the results of this yet.

Sooner or later it is likely that your relative may need more chemotherapy and it is important that she considers enrolling in a clinical trial of a PARP inhibitor. These drugs appear to work best in patients with BRCA mutations but are still being evaluated in clinical trials. I hope that the Anastrazole is effective and wish you both the best.