Amenorrhoea, menopause, and endocrine therapy for breast cancerBMJ 2009; 339 doi: https://doi.org/10.1136/bmj.b4261 (Published 03 December 2009) Cite this as: BMJ 2009;339:b4261
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The word menopause is derived from the Greek words “menos” meaning
month and “pausis” meaning cessation. It literally means the last period.
because we could not predict which period is going to be the final one in
woman’s life, the menopause has to be a retrospective diagnosis. Thus
menopause is diagnosed after 12 months of amenorrhoea for women over
the age of 50. For women under the age of 50, the Faculty of Sexual and
Reproductive Healthcare (FSRH) recommend an even longer interval of 24
months before stating a woman is post-menopausal.  The rationale behind
this recommendation comes from the World Health Organisation (WHO) and
their estimate that the probability of further menstruation after a year
amenorrhoea is between 2-10%. 
Tamoxifen is a selective estrogen receptor modulator and as such can
estrogen receptors found within the breast and endometrium. It is used in
the treatment of breast cancer. Aromatase inhibitors are also used but
use as single agents is confined to post-menopausal women. Amir et al
highlighted how difficult it can be to get the diagnosis of menopause
and how there can be serious consequences from using aromatase inhibitors
in women that have been falsely diagnosed as post-monopausal.  There
are serious implications too however in failing to diagnose the menopause
among women using tamoxifen. Tamoxifen may be used in pre- and post-
menopausal women but when used in post-menopausal women any vaginal
bleeding that occurs should trigger suspicion and an urgent referral to
gynaecolgists to exclude endometrial pathology.  If the clinician
believes that his patient’s bleeding is simply related to menstruation he
not refer her on for further investigation and failure to do so may result
delayed diagnosis of endometrial cancer. Thus although it can be tricky to
ascertain whether a woman is pre- or post menopausal, this important
feature of her history should not be neglected and must be taken into
consideration when prescribing certain treatments.
1. Faculty of Sexual and Reproductive Healthcare Clinical
FSRH Guidance. Contraception for women aged over 40 years (January 2005).
J Fam Plann Reprod Health Care2005; 31(1): 63-51.
2. World Health Organization. Progress in Reproductive Health.
and the Late Perimenopause. 40(2). 1996.
3. Amir E et al. Amenorrhoea, menopause and endocrine therapy for
cancer. BMJ 2009;339:b4261
4. Nice clinical guidance : Referral for suspected cancer. Available
Competing interests: No competing interests