Associations of hormone replacement therapy and oral contraceptives with risk of colorectal cancer defined by clinicopathological factors, beta-catenin alterations, expression of cyclin D1, p53, and microsatellite-instability

• BACKGROUND: Postmenopausal hormone therapy (HRT) and oral contraceptive (OC) use have in several studies been reported to be associated with a decreased colorectal cancer (CRC) risk. However, data on the association between HRT and OC and risk of different clinicopathological and molecular subsets of CRC are lacking. The aim of this molecular pathological epidemiology study was therefore to evaluate the associations between HRT and OC use and risk of specific CRC subgroups, overall and by tumour site.METHOD: In the population-based prospective cohort study Mamö Diet and Cancer, including 17035 women, 304 cases of CRC were diagnosed up until 31 December 2008. Immunohistochemical expression of beta-catenin, cyclin D1, p53 and MSI-screening status had previously been assessed in tissue microarrays with tumours from 280 cases. HRT was assessed as current use of combined HRT (CHRT) or unopposed oestrogen (ERT), and analysed among 12583 peri-and postmenopausal women. OC use was assessed as ever vs never use among all women in the cohort. A multivariate Cox regression model was applied to determine hazard ratios for risk of CRC, overall and according to molecular subgroups, in relation to HRT and OC use.RESULTS: There was no significantly reduced risk of CRC by CHRT or ERT use, however a reduced risk of T-stage 1-2 tumours was seen among CHRT users (HR: 0.24; 95% CI: 0.09-0.77).Analysis stratified by tumour location revealed a reduced overall risk of rectal, but not colon, cancer among CHRT and ERT users, including T stage 1-2, lymph node negative, distant metastasis-free, cyclin D1 - and p53 negative tumours.In unadjusted analysis, OC use was significantly associated with a reduced overall risk of CRC (HR: 0.56; 95% CI: 0.44-0.71), but this significance was not retained in adjusted analysis (HR: 1.05: 95% CI: 0.80-1.37). A similar risk reduction was seen for the majority of clinicopathological and molecular subgroups.CONCLUSION: Our findings provide information on the relationship between use of HRT and OC and risk of clinicopathological and molecular subsets of CRC.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Nyckelord

Biomarkers, Tumor

Colorectal Neoplasms

Contraceptives, Oral, Hormonal

Cyclin D1

Estrogen Replacement Therapy

Female

Genetic Predisposition to Disease

Humans

Immunohistochemistry

Microsatellite Instability

Middle Aged

Multivariate Analysis

Neoplasm Staging

Proportional Hazards Models

Prospective Studies

Risk Assessment

Risk Factors

Sweden

Time Factors

Tissue Array Analysis

Tumor Suppressor Protein p53

beta Catenin

Journal Article

Research Support, Non-U.S. Gov't

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)