The Editorial Executive Committee welcomes letters, which should be less than 250 words. Before a decision to publish is made, letters which refer to a published article may be sent to the author for a response. Any letter may be sent to an expert for comment. When letters are published, they are usually accompanied in the same issue by their responses or comments. The Committee screens out discourteous, inaccurate or libellous statements. The letters are sub-edited before publication. Authors are required to declare any conflicts of interest. The Committee's decision on publication is final.

Letter to the editor

Editor, – I refer to Dr D. Palmer's article on this subject (Aust Prescr 1994;17:13-6). It is annoying that oestrogen alone is constantly promoted as hormone-replacement therapy (HRT) for women after hysterectomy. Should not HRT be just that -- therapy to provide a hormone profile similar to the premenopausal level? If progestogens are found to be protective for breast cancer1, how can we as a profession be taken seriously when promoting hormonal therapy with oestrogen only? Once bitten (1960s), twice shy (1990s). First - do no harm.

G. Bates
General Practitioner
North Ringwood, Vic

Dr D. Palmer, the author of the article, comments:

Oestrogen is recommended as unopposed therapy for women post-hysterectomy because it is the specific medication required to relieve symptoms and to protect against future disease. Progestogens were added to HRT regimens after being shown to protect against the increased risk of endometrial carcinoma. While it may be logical to include progestogens in all HRT regimens to mimic the premenopausal hormone profile, their effect on breast tissue remains unclear and they have associated problems.

There is debate whether progestogens antagonise the effect of oestrogen on breast tissue in the way that they protect endometrium. It is uncertain whether the increased mitotic activity in breast epithelium in the luteal phase of the cycle is a concern when using exogenous progestogen.2

A recent meta-analysis of 4 studies3 specifically addressed the hypothesis that the addition of progestogen to oestrogen reduces the risk of breast cancer. Contrary to Gambrell's earlier study4 (which did not adjust for age), use of combined HRT did not reduce the overall slight increase in relative risk of breast cancer.

Progestogenic adverse effects, while not life-threatening have been suggested as being one of the most important reasons for women stopping HRT.5 The potential adverse effects of progestogens on lipid profiles and attenuation of the beneficial effect of oestrogen on cardiovascular disease are controversial. These have not been significant in most short-term studies, but long-term results are not available.

Thus, despite limited data suggesting addition of progestogen may protect against breast cancer, most authorities6 would consider the data insufficient to warrant progestogen use in women who have had a hysterectomy; especially in view of the small but real incidence of adverse effects and the theoretical adverse effects on lipid profile.


  1. Gambrell RD Jr. Estrogen replacement therapy and breast cancer risk. A new look at the data. Female patient 1993;18:50,55-60,62.
  2. Anderson U, Battersby S, King RJ, McPherson K, Going JJ. Oral contraceptive use influences resting breast proliferation. Hum Pathol 1989;20:1139-44.
  3. Colditz GA, Egan KM, Stampfer MJ. Hormone replacement therapy and risk of breast cancer: results from epidemiologic studies. Am J Obstet Gynecol 1993;168:1473-80.
  4. Gambrell RD Jr, Maier RC, Sanders Bl. Decreased incidence of breast cancer in postmenopausal estrogen-progestogen users. Obstet Gynecol 1983;62:435-43.
  5. Smith RN, Holland EF, Studd J W The symptomatology of progestogen intolerance. Maturitas 1994;18:87-91.
  6. Khoo SK. Cancer, the menopause and hormone replacement therapy. Aust Prescr 1993;16:66-8.