Hormone therapy linked to reduced risk of colorectal cancer: Study
Menopausal hormone therapy is associated with an overall reduced odds for colon and rectal adenocarcinoma, especially among women aged 40 to 60 years.
Sweden: The use of menopausal hormone therapy (MHT) may lessen the risk of colorectal cancer (CRC) in women, finds a recent study in the journal Alimentary Pharmacology & Therapeutics.
Menopausal hormone therapy has been associated with various malignancies. Qing Liu, Karolinska Institutet, Stockholm, Sweden, and colleagues aimed to investigate the association of various MHT regimens with the risk of colorectal cancer.
The study included all the MHT ever-users (n = 290 186) through the Swedish Prescribed Drug Registry, with a 1:3 group-level matching to non-users. Ever-users were defined as women who received ≥1 dispensed prescription of systemic MHT during 2005-2012 in Sweden. All CRC cases following the drug initiation were extracted from the Swedish Cancer Registry.
The association was assessed by multivariable conditional logistic and Cox regression models, presented as odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (CIs) considering different regimens, duration, and age at treatment initiation.
Key findings of the study include:
- Compared with non-users, MHT users had an overall reduced odds for colon (OR = 0.67) and rectal adenocarcinoma (OR = 0.66), especially among women aged 40-60 years.
- Current users of estrogen-only preparations (E-MHT) showed a reduced odds (colon OR = 0.73; rectal OR = 0.76) compared to non-users, particularly with oestradiol and oestriol.
- Past E-MHT use showed stronger odds reductions (colon OR = 0.49; rectal OR = 0.36).
- Current use of estrogen combined progestin therapy (EP-MHT) indicated a less prominent odds reduction (colon adenocarcinoma OR 0.62; rectal adenocarcinoma OR = 0.60) than past users.
- Tibolone showed an increased risk of left-sided colorectal adenocarcinoma.
- Oral and cutaneous MHT usage showed similar patterns.
"MHT use may decrease colorectal adenocarcinoma risk, for both E-MHT and EP-MHT, and especially in past users," concluded the authors.
The study titled, "Menopausal hormone therapies and risk of colorectal cancer: a Swedish matched-cohort study," is published in the journal Alimentary Pharmacology & Therapeutics.