Definition
From a symptomatic perspective, postmenopausal bleeding describes the occurrence of vaginal bleeding following a woman’s last menstrual cycle. There is some debate regarding the minimum time period that must have passed after the end of menstruation before PMB can be considered to have taken place. An episode of bleeding 12 months or more after the last period is accepted as postmenopausal.

What if you are on HRT?
Abnormal bleeding in women using hormone replacement therapy (HRT) can be difficult to assess . For sequential (cyclical) regimens, abnormal bleeding may be considered if a woman experiences heavy or prolonged bleeding at the end of or after the progestogen phase or if bleeding occurs at an unscheduled time during the cycle. For women on tibolone or continuous combined HRT it can take up to six months for amenorrhoea (no bleeding) to develop. Therefore in these women bleeding should be considered abnormal if it occurs after six months of treatment or if it occurs after amenorrhea has been established.

Risk of endometrial cancer
The absolute risk of endometrial cancer in non-users of HRT who present with PMB ranges from 5.7 to 11.5%

  • Age – The probability of endometrial cancer being present in women with PMB increased with age
  • Hormone replacement therapy (HRT) – Older HRT regimens that utilise unopposed oestrogen increase the relative risk of endometrial cancer by around six times after five years of use Progestogens are added to HRT regimens to prevent endometrial hyperplasia and cancer. Their inclusion reduces the relative risk of endometrial cancer to around 1.5
  • Tamoxifen – Women receiving tamoxifen in the treatment or prevention of breast cancer experience a three to six fold greater incidence of endometrial cancer. The risk of endometrial cancer rises with both the use of higher doses and increasing duration of tamoxifen use.

Other risk factors – Hereditary non-polyposis colorectal cancer (HNPCC) is one of the commonest inherited cancer syndromes. Its inheritance is autosomal dominant. The estimated lifetime risk of developing endometrial cancer in women carrying these mutations is around 42 to 60%. Importantly, in contrast to ‘sporadic’ endometrial cancer, women from such affected families usually develop endometrial cancer premenopausally

Other causes of PMB

  • Uterine polyps – Uterine polyps are noncancerous growths. Though mostly benign, some polyps can cancerous. Uterine polyps are particularly common in women who have gone through menopause. However, younger women can also get them.
  • Endometrial hyperplasia – Endometrial hyperplasia is the thickening of the endometrium. It is a potential cause for postmenopausal bleeding. It is often caused when there is an excess of estrogen without enough progesterone. It occurs frequently in women after menopause. Long-term use of estrogen can lead to increased risk of endometrial hyperplasia. It can ultimately lead to cancer of the uterus if not treated.
  • Endometrial atrophy – This condition results in the endometrial lining becoming too thin. It can occur in postmenopausal women. As the lining thins, bleeding may occur.
  • Cervical cancer – It can also be a rare sign of cervical cancer.

What to expect during assessment?
Women presenting with PMB require a pelvic examination, including speculum examination at some stage during their assessment.

Investigations

  • Transvaginal Ultrasound
  • Endometrial sampling
  • Hysteroscopy and dilatation and curettage

Management
Dependent on the cause of the bleeding