Menopausal hormone therapy and colorectal cancer: a linkage between nationwide registries in Norway.

Abstract

OBJECTIVES:

With the present study, we aimed to investigate the association between menopausal hormone therapy (HT) and risk of colorectal cancer (CRC).

SETTING:

Cohort study based on the linkage of Norwegian population-based registries.

PARTICIPANTS:

We selected 466822 Norwegian women, aged 55-79, alive and residing in Norway as of 1 January 2004, and we followed them from 2004 to 2008. Each woman contributed person-years at risk as non-user, current user and/or past HT user.

OUTCOME MEASURES:

The outcome of interest was adenocarcinoma of the colorectal tract, overall, by anatomic site and stage at diagnosis. Incidence rate ratios (RRs) with 95% CIs were estimated by Poisson regression and were used to evaluate the association between HT and CRC incidence.

RESULTS:

During the median follow-up of 4.8 years, 138 655 (30%) women received HT and 3799 (0.8%) incident CRCs occurred. Current, but not past, use of HT was associated with a lower risk of CRC (RR 0.88; 95% CI 0.80 to 0.98). RRs for localised, regionally advanced and metastatic CRC were 1.13 (95% CI 0.91 to 1.41), 0.81 (95% CI 0.70 to 0.94) and 0.79 (95% CI 0.62 to 1.00), respectively. RRs for current use of oestrogen therapy (ET) were 0.91 (95% CI 0.80 to 1.04) while RR for current use of combined oestrogen-progestin therapy (EPT) was 0.85 (95% CI 0.70 to 1.03), as compared with no use of HT. The same figures for ET and EPT in oral formulations were 0.83 (95% CI 0.68 to 1.03) and 0.86 (95% CI 0.71 to 1.05), respectively.

CONCLUSIONS:

In our nationwide cohort study, HT use lowered the risk of CRC, specifically the most advanced CRC.

• Authors: Edoardo Botteri, Nathalie C Støer, Solveig Sakshaug, Sidsel Graff-Iversen, Siri Vangen, Solveig Hofvind, Thomas de Lange, Vincenzo Bagnardi, Giske Ursin, Elisabete Weiderpass
• Journal: BMJ open (BMJ Open) Vol. 7 Issue 11 Pg. e017639 (Nov 15 2017) ISSN: 2044-6055 [Electronic] England
• PMID: 29146641 (Publication Type: Journal Article)
• Copyright: © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Topics

• Aged
• Colorectal Neoplasms (epidemiology, prevention & control)
• Estrogen Replacement Therapy
• Female
• Follow-Up Studies
• Humans
• Incidence
• Middle Aged
• Norway (epidemiology)
• Poisson Distribution
• Postmenopause
• Registries
• Risk Factors