HRT and Breast Cancer Risk
As explained earlier in this book, oestrogen seems to promote breast cancer growth. However, the risk of breast cancer is increased by 30% in women who have taken HRT for more than 5 years.
Women taking HRT should still practise self-examination of the breasts and participate in breast cancer screening programmes (one mammogram every two years). It is also worth pointing out that breast cancers that develop in women taking HRT are usually early cancers and have a good prognosis.
The above advice also applies to women with a family history of breast cancer. Women who have had breast cancer will probably be taking tamoxifen (see Chapter 2). This drug has similar beneficial effects on the bones as HRT. If these women have severe menopausal symptoms, such as hot flushes and vaginal dryness, then HRT can still be considered. However, it is usually preferable to try alternative drugs to improve these symptoms. Alternatives to HRT in the treatment of postmenopausal symptoms include progesterone tablets, oestrogen creams and Prozac-like drugs. Progesterone tablets can relieve hot flushes and oestrogen creams can be used in the vagina to improve dryness and discomfort. Remember that oestrogen creams applied in the vagina can still be absorbed into the blood stream, and only small amounts should be applied for short periods (maximum of three weeks) and repeated as necessary.
If you have had breast cancer, it is worth asking your breast specialist about the type of cancer you had. Some types of breast cancer are sensitive to oestrogen and the hormone stimulates tumour growth, while other types of breast cancer are not affected by oestrogen. If your cancer was of the non-oestrogen-sensitive type, HRT is less likely to increase the risk of the breast cancer returning.
It is the author's opinion that women with breast cancer should avoid using HRT for at least two years after diagnosis. The development of new drugs to reduce the risk of bone loss or osteoporosis, such as bisphosphonates and raloxifene, is likely to reduce the need to use HRT among all women.
A recent study from the USA (the Women's Health Initiative Study) has shown that taking HRT increases the risk of heart disease and breast cancer but decreases the risk of brittle bone disease and large bowel cancer. It is the author's opinion that the disadvantages of HRT outweigh its benefits and should be used only as a last resort.