Hormone replacement therapy increases the incidence of breast cancer in postmenopausal women.

Abstract

An increase in life expectancy has meant that more women are affected by a decline in hormone production which is associated with a series of short-term problems and prolonged debilitating effects. Despite 50 years of Hormone Replacement Therapy (HRT) use with estrogen or estrogen/progestin preparations, the limited available research offer contradictory results with regards to their associated risks and benefits in relation to breast cancer. Hence, the aim of this research was to investigate if postmenopausal women, who have received HRT, compared to those without exposure are at a higher risk of developing breast cancer. A search strategy using various established databases together with internet search engines and manual searches was carried out. The established inclusion/exclusion criteria set for the literature search included postmenopausal women, age group 45 years and above on HRT or not, who have developed breast cancer. Such search resulted in the identification of 9 research studies including a randomized controlled trial (RCT), 4 systematic reviews/meta-analyses and 4 observational cohorts. These studies were assessed for quality using established tools, mainly the Critical Appraisal Skills Programme (National Health Service [NHS], 2011) and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA, 2009). An overall majority of the research studies reported a statistically significant association between HRT and breast cancer. Moreover, current use of estrogen-progestin combinations is associated with a higher incidence of breast cancer than estrogen only formulations. Results are also indicative of an increase in breast cancer incidence with current use for more than five years and that the risk starts to decrease till it wears off and returns to null after five years of ceasing treatment. Such results are supportive of local research studies investigating the relationship between breast cancer and HRT use in Malta and the establishment of a joint collaboration standard procedure between the postmenopausal woman and the gynaecologist/physician to establish individual risk factors and potential other alternative therapies prior the commencement of HRT treatment. Finally, educating health care professionals and patients alike to generate awareness about the associated risks to such treatment was also recommended.