An over-risk of breast cancer persists even after stopping hormone replacement therapy for menopause, according to a recent study.
This is probably the epilogue of a long story. New data published in The Lancet, Friday, Aug. 29, confirm that women on hormone replacement therapy (HRT) for menopause have an increased risk of developing breast cancer. This is not new, but it is also shown that all types of HRT are associated with an over-risk of breast cancer, except for local treatments. Five years of HRT from the age of 50 increases the risk of breast cancer by one additional case for 50 women treated with combination estrogen and progestogen treatment. Most importantly, the study demonstrates that there is a residual risk that persists for up to ten years after stopping treatment.
The increase is less pronounced with combined treatment with intermittent progestins (an additional case for 70 treated women) and lower with estrogen alone. "The type of hormone therapy for menopausal disorders with the lowest risk increase is estrogen alone, but this treatment is reserved for women in whom the uterus has been removed, which is not the case. the majority of patients on HRT »remarks Professor Anthony Gonçalves, head of the oncology department at the Paoli-Calmettes Institute (Marseille). The results also suggest that the risk for a ten-year treatment period is twice as high as for five years.
The authors examined 58 studies, conducted from January 1992 to January 2018, and individual data from 108,647 postmenopausal women who developed breast cancer at the mean age of 65, during the 20 years of follow-up, half of whom (51%) had used these treatments. The average age of menopause was 50 years old.
"This study of high statistical power and a very good methodology was conducted by a team that includes some of the biggest names in epidemiology, like Valerie Beral, from Oxford University, who spent his life studying the relationship between hormones and cancer, or Richard Peto, says Annie Sasco, a doctor epidemiologist specializing in cancer (University of Bordeaux).
Annoying symptoms of menopause
During menopause, the cessation of ovarian function causes the production of hormones (estrogen and / or progesterone), which are no longer naturally produced by the body, to drop, except for a small production of estrogen by adipose tissue. This can cause troublesome symptoms (insomnia hot flashes, fatigue, low libido …) that HRT attenuates or even eliminates.