High Breast Cancer Risk With Menopausal Hormone Therapy & Strong Family History

TOPLINE:

The use of menopausal hormone therapy (MHT) increases breast cancer risk in women with a strong family history of breast cancer. These women have a striking cumulative risk of developing breast cancer (age, 50-80 years) of 22.4%, according to a new modelling study of UK women.

METHODOLOGY:

This was a modeling study integrating two data-sets of UK women: the BOADICEA dataset of age-specific breast cancer risk with family history and the Collaborative Group on Hormonal Factors in Breast Cancer, which covers relative risk for breast cancer with different types and durations of MHT.

Four different breast cancer family history profiles were:

• “Average” family history of breast cancer has unknown affected family members;
• “Modest” family history comprises a single first-degree relative with breast cancer at the age of 60 years.
• “Intermediate” family history comprises a single first-degree relative who developed breast cancer at the age of 40 years.
• “Strong” family history comprises two first-degree relatives who developed breast cancer at the age of 50 years.

TAKEAWAY:

• The lowest risk category: “Average” family history with no MHT use has a cumulative breast cancer risk (age, 50-80 years) of 9.8% and a risk of dying from breast cancer of 1.7%. These risks rise with 5 years’ exposure to MHT (age, 50-55 years) to 11.0% and 1.8%, respectively.
• The highest risk category: “Strong” family history with no MHT use has a cumulative breast cancer risk (age, 50-80 years) of 19.6% and a risk of dying from breast cancer of 3.2%. These risks rise with 5 years’ exposure to MHT (age, 50-55 years) to 22.4% and 3.5%, respectively.

IN PRACTICE:

The authors concluded that, “These integrated data will enable more accurate estimates of absolute and attributable risk associated with MHT exposure for women with a family history of breast cancer, informing shared decision-making.”

SOURCE:

The lead author is Catherine Huntley of the Institute of Cancer Research, London, England. The study appeared in the British Journal of General Practice.

LIMITATIONS:

Limitations included modeling study that did not directly measure individuals with combined risks.

DISCLOSURES:

The study was funded by several sources including Cancer Research UK. The authors reported no conflicts of interest.

A version of this article first appeared on Medscape.com.