Breast cancer with different prognostic characteristics developing in Danish women using hormone replacement therapy

TY - JOUR

T1 - Breast cancer with different prognostic characteristics developing in Danish women using hormone replacement therapy

AU - Stahlberg, Claudia

AU - Pedersen, A T

AU - Andersen, Zorana Jovanovic

AU - Keiding, N

AU - Hundrup, Y A

AU - Obel, E B

AU - Møller, S

AU - Rank, F

AU - Ottesen, B

AU - Lynge, E

PY - 2004/8/16

Y1 - 2004/8/16

N2 - The aim of this study is to investigate the risk of developing prognostic different types of breast cancer in women using hormone replacement therapy (HRT). A total of 10 874 postmenopausal Danish Nurses were followed since 1993. Incident breast cancer cases and histopathological information were retrieved through the National Danish registries. The follow-up ended on 31 December 1999. Breast cancer developed in 244 women, of whom 172 were invasive ductal carcinomas. Compared to never users, current users of HRT had an increased risk of a hormone receptor-positive breast cancer, but a neutral risk of receptor-negative breast cancer, relative risk (RR) 3.29 (95% confidence interval (CI): 2.27-4.77) and RR 0.99 (95% CI: 0.42-2.36), respectively (P for difference=0.013). The risk of being diagnosed with low histological malignancy grade was higher than high malignancy grade with RR 4.13 (95% CI: 2.43-7.01) and RR 2.17 (95% CI: 1.42-3.30), respectively (P=0.063). For breast cancers with other prognostic characteristics, the risk was increased equally for the favourable and non favourable types. Current users of HRT experience a two- to four-fold increased risk of breast cancer with various prognostic characteristics, both the favourable and non favourable types. For receptor status, the risk with HRT was statistically significantly higher for hormone receptor-positive breast cancer compared to receptor-negative breast cancer.

AB - The aim of this study is to investigate the risk of developing prognostic different types of breast cancer in women using hormone replacement therapy (HRT). A total of 10 874 postmenopausal Danish Nurses were followed since 1993. Incident breast cancer cases and histopathological information were retrieved through the National Danish registries. The follow-up ended on 31 December 1999. Breast cancer developed in 244 women, of whom 172 were invasive ductal carcinomas. Compared to never users, current users of HRT had an increased risk of a hormone receptor-positive breast cancer, but a neutral risk of receptor-negative breast cancer, relative risk (RR) 3.29 (95% confidence interval (CI): 2.27-4.77) and RR 0.99 (95% CI: 0.42-2.36), respectively (P for difference=0.013). The risk of being diagnosed with low histological malignancy grade was higher than high malignancy grade with RR 4.13 (95% CI: 2.43-7.01) and RR 2.17 (95% CI: 1.42-3.30), respectively (P=0.063). For breast cancers with other prognostic characteristics, the risk was increased equally for the favourable and non favourable types. Current users of HRT experience a two- to four-fold increased risk of breast cancer with various prognostic characteristics, both the favourable and non favourable types. For receptor status, the risk with HRT was statistically significantly higher for hormone receptor-positive breast cancer compared to receptor-negative breast cancer.

KW - Aged

KW - Breast Neoplasms

KW - Carcinoma, Ductal, Breast

KW - Cohort Studies

KW - Denmark

KW - Epidemiologic Studies

KW - Female

KW - Hormone Replacement Therapy

KW - Humans

KW - Incidence

KW - Middle Aged

KW - Postmenopause

KW - Prognosis

KW - Registries

KW - Risk Factors

KW - Survival Analysis

U2 - 10.1038/sj.bjc.6601996

DO - 10.1038/sj.bjc.6601996

M3 - Journal article

C2 - 15238982

SN - 0007-0920

VL - 91

SP - 644

EP - 650

JO - The British journal of cancer. Supplement

JF - The British journal of cancer. Supplement

IS - 4

ER -