Risk-reducing options

Breast awareness

Risk-reducing options

Risk reducing (prophylactic) surgery

If you find out that you do have an inherited genetic mutation that raises your risk of breast and/or ovarian cancer, you might want to consider these risk-reducing options.

Risk reducing (prophylactic) surgery

Risk-reducing (prophylactic) bilateral mastectomy

Having both breasts removed reduces the risk of breast cancer by 95%. It’s not possible for the surgeon to remove every remnant of breast tissue so some risk always remains. Self-surveillance is advised in the future.

Risk-reducing removal of the ovaries and fallopian tubes or BSO (bilateral salpingo oophorectomy)

In this procedure, both ovaries and fallopian tubes are removed to reduce the risk of ovarian cancer. This can often be done via three small “keyhole” incisions in the abdomen, using a laparoscope (a flexible tube with an attached camera). If the laparoscopic method is not appropriate then the ovaries can be removed through a short incision in the lower abdomen.

This reduces ovarian cancer risk by 98% if performed at or by the age of 40. It is not advised in younger women because of the long-term effects of a prolonged period of oestrogen depletion. HRT may be given for five years following the surgery if necessary to help with the side-effects of an instant surgical menopause. The side effects can be more severe than a more gradual, natural menopause.

Removal of the ovaries also reduces the risk of breast cancer in pre-menopausal women by 50-60%


Women with a confirmed high-risk genetic mutation would usually be recommended annual mammograms and MRIs which are alternated so that one is performed every six months. This is generally funded in the public hospital system, although funding constraints may exist in some DHBs. After the age of 50 years, the need for MRI may be reassessed. Annual clinical breast examinations are also recommended.

Risk-reducing medication

Clinical trials have shown that drugs which block or reduce oestrogen in the body can reduce the risk of breast cancer in high risk women. Tamoxifen can be used for pre- and post-menopausal women and anastrozole for post-menopausal women. This requires an in-depth discussion with your breast specialist, as side effects need to be taken into consideration. This is more suited to BRCA2 mutations, as BRCA1 cancers are most commonly not oestrogen sensitive.

What are my options if I am at moderate risk?

There are several options available if you are at moderately increased risk:

  • Surveillance with clinical checks and regular imaging .
  • Annual mammograms between 40-50, and two-yearly mammograms from 50 (or annually if breasts are very dense).
  • Risk reducing medication (tamoxifen or anastrozole) could be considered.
  • Risk-reducing surgery is not usually recommended for the moderate risk group, but patterns of family history and psychological factors are taken into consideration.
  • Women and men of all ages, and in all risk groups, must be aware of any breast changes and report them promptly.