Hormone Replacement Therapy, Likely Neither Angel Nor Demon

Area of Science:

• Oncology
• Epidemiology
• Public Health

Background:

• Hormone replacement therapy (HRT) use has been linked to breast cancer incidence, with a notable decline in prescriptions following the 2003 Women's Health Initiative (WHI) paper.
• Previous analyses have not comprehensively evaluated HRT prescription trends against breast cancer incidence over extended periods.

Purpose of the Study:

• To analyze the relationship between hormone replacement therapy (HRT) prescription rates and breast cancer incidence using extensive Surveillance, Epidemiology, and End Results (SEER) data.
• To investigate potential associations between declining HRT use and the incidence of other health conditions, including cardiovascular diseases and fractures.

Main Methods:

• Utilized SEER data (1992-2012) for breast and endometrial carcinoma incidence rates in women over 50.
• Incorporated data from the Medical Expenditure Panel Survey (1996-2012) for HRT prescription trends and the National Hospital Discharge Survey (1996-2010) for major health event incidence.
• Applied Joinpoint regression analysis to evaluate trends and changes in incidence rates over time.

Main Results:

• HRT prescription rates decreased significantly from 2001 to 2012 (AAPC -14.9%).
• Breast cancer rates, after an initial decline, showed an increase post-2003, with rates in 2012 similar to 2001 levels for both ductal and lobular carcinomas.
• Endometrial carcinoma rates increased during the study period, and no significant differences in the trends of femoral neck fractures, hip replacements, myocardial infarctions, or cerebral infarctions were detected across genders, suggesting no general HRT effect.

Conclusions:

• Changes in breast cancer incidence rates cannot be attributed to the observed shifts in hormone replacement therapy (HRT) prescription patterns.
• The study did not find evidence to support a general association between HRT discontinuation and the incidence of major health conditions like cardiovascular events or fractures.