While the causes of uterine cancer are unknown, a high level of oestrogen has been found to play a role in its development. Other risk factors include:

• Starting menstruation early – before the age of 12
• Late menopause
• Never having been pregnant
• Older age
• Obesity
• Irregular and infrequent periods – less than 4 periods in a year
• Oestrogen-only replacement therapy (ERT)
• Endocrine therapy drug called Tamoxifen for breast cancer
• Polycystic ovarian syndrome (PCOS)
• Family history of breast, uterine, ovarian or colon cancer