Colorectal cancer (CRC) is the second most frequently diagnosed cancer in females worldwide. Menopausal hormone therapy (MHT) has been proposed as a potential protective factor for the development of CRC. Yet, the available evidence is controversial. ...
Colorectal cancer (CRC) is the second most frequently diagnosed cancer in females worldwide. Menopausal hormone therapy (MHT) has been proposed as a potential protective factor for the development of CRC. Yet, the available evidence is controversial. Thus, we aimed at summarizing the current evidence on the effect of MHT on CRC through a systematic review. A systematic literature search identified 1001 potentially relevant articles, out of which 57 original studies and nine meta‐analyses were deemed eligible for the final synthesis. The evidence synthesis showed the following: (1) MHT showed a heterogeneity in findings for CRC risk with a slight tendency to a neutral or protective effect; (2) MHT effect was either neutral or protective on colorectal adenoma; (3) MHT had no impact on tumour grade, subsite and histologic types; (4) MHT was not associated with CRC mortality; and (5) MHT showed heterogeneous effects on CRC stage and invasiveness, respectively. In summary, despite some evidence pointing towards a protective effect of MHT on CRC, MHT is currently not recommended for primary CRC prevention by international guidelines due to several important, potentially harmful effects.