Summary Safety Review - Hormone Replacement Therapy (Estrogenic and Progestogenic Agents) and Selective Estrogen Receptor Modulators (SERMs) - Assessing the Potential Risk of Ovarian Cancer

Review decision

A Summary Safety Review complements other safety related information to help Canadians make informed decisions about their use of health products. Each summary outlines what was assessed in Health Canada’s review, what was found and what action was taken by Health Canada, if any.


Issued: 2016-08-09

Product

Hormone replacement therapy (estrogenic and progestogenic agents) and selective estrogen receptor modulators (SERMs)

Potential Safety Issue

Ovarian cancer in menopausal women

Key Messages

  • Hormone replacement therapy (HRT) products containing estrogens and/or progestogens are used to treat symptoms of menopause and in some cases, to prevent weakening of bones (osteoporosis). Some selective estrogen receptor modulators (SERMs) (raloxifene, bazedoxifene) are also used for these same purposes.
  • This safety review was triggered following the publication of a study showing a potential for increased risk of ovarian cancer in women undergoing HRT for less than 5 years.
  • As of 2008, the Canadian product information for HRT products includes warning statements about the risk of ovarian cancer during treatment, especially after 5 years of treatment or more.
  • Health Canada's safety review did not identify any changes in the known risk of ovarian cancer in women undergoing HRT. The review did not find evidence for a link between SERMs (raloxifene, bazedoxifene) and ovarian cancer.

Overview

Based on a publication of a study suggesting that the risk of ovarian cancer may be increased in women undergoing HRT for less than 5 years, Health Canada carried out a safety review to further assess this risk and to determine if additional changes to the product information are needed. As of 2008, the Canadian product information for HRT products includes warning statements about the risk of ovarian cancer during treatment, especially after 5 years of treatment or more. Although SERMs (raloxifene, bazedoxifene) were not included in that study, Health Canada also assessed the risk of ovarian cancer with this class of drugs since they may have similar effects in the body.

Use in Canada

  • HRT products containing estrogens and/or progestogens are used to treat menopausal symptoms such as hot flashes, night sweats, and vaginal dryness. Some HRT products are also used to prevent weakening of bones (osteoporosis). Selective estrogen receptor modulators (SERMs) (raloxifene, bazedoxifene) are also used for preventing and treating osteoporosis and some symptoms of menopause.
  • There are 37 HRT products (containing estrogen and/or progesterone) and 7 SERMs products (containing raloxifene or bazedoxifene) approved for use in postmenopausal women in Canada.

Safety Review Findings

  • At the time of the review, there was 1 Canadian case of ovarian cancer reported in a patient undergoing HRT, but there was not enough information to determine a link between HRT and ovarian cancera. There were no Canadian cases of ovarian cancer reported with the use of SERMs (raloxifene, bazedoxifene) for symptoms of menopause.
  • A published studyb showed the potential for a higher risk of ovarian cancer in women undergoing HRT for less than 5 years. Health Canada's safety review found limitations, which questioned the conclusions of the study. Most studies, showing a link between HRT and ovarian cancer, are related to undergoing HRT for 5 years or more.
  • The review did not find published studies looking at the link between ovarian cancer and SERM use in menopausal women.

Conclusions and actions

  • At this time, Health Canada's safety review did not find enough information to confirm that the risk of ovarian cancer is increased in women undergoing HRT for less than 5 years. The current Canadian product information for HRT products warns about the risk of ovarian cancer during treatment, especially after 5 years of treatment or more.
  • The safety review did not find evidence for a link between SERMs (raloxifene, bazedoxifene) and ovarian cancer.
  • Based on the review findings, no changes will be made to the product information for HRT or SERMs at this time. Health Canada will continue to monitor side effect information involving HRT and SERMs, as it does for all health products on the Canadian market, to identify and assess potential harms. Health Canada will take appropriate and timely action if and when any new health risks are identified.

Additional information

The analysis that contributed to this safety review included scientific and medical literature, Canadian and international adverse reaction reports and what is known about the use of this drug both in Canada and internationally.

For additional information, contact the Marketed Health Products Directorate.

Footnotes

  1. Canadian reports can be accessed through the Canada Vigilance Online Database.
  2. Collaborative Group on Epidemiological Studies of Ovarian Cancer. Menopausal hormone use and ovarian cancer risk: individual participant meta-analysis of 52 epidemiological studies. The Lancet. 2015; Volume 385, Issue 9980, Pages 1835-1842.