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Menopausal hormone therapy and breast cancer risk: Impact of different treatments. The European Prospective Investigation into Cancer and Nutrition
Author(s) -
Bakken Kjersti,
Fournier Agnès,
Lund Eiliv,
Waaseth Marit,
Dumeaux Vanessa,
ClavelChapelon Françoise,
Fabre Alban,
Hémon Bertrand,
Rinaldi Sabina,
Chajes Véronique,
Slimani Nadia,
Allen Naomi E.,
Reeves Gillian K.,
Bingham Sheila,
Khaw KayTee,
Olsen Anja,
Tjønneland Anne,
Rodriguez Laudina,
Sánchez MariaJosé,
Etxezarreta Pilar Amiano,
Ardanaz Eva,
Tormo MariaJosé,
Peeters Petra H.,
van Gils Carla H.,
Steffen Annika,
Schulz Mandy,
ChangClaude Jenny,
Kaaks Rudolf,
Tumino Rosario,
Gallo Valentina,
Norat Teresa,
Riboli Elio,
Panico Salvatore,
Masala Giovanna,
González Carlos A.,
Berrino Franco
Publication year - 2010
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.25314
Subject(s) - medicine , breast cancer , hazard ratio , oncology , estrogen , relative risk , gynecology , proportional hazards model , european prospective investigation into cancer and nutrition , cancer , hormone therapy , confidence interval , prospective cohort study , cohort , hormone replacement therapy (female to male) , population , testosterone (patch) , environmental health
Menopausal hormone therapy (MHT) is characterized by use of different constituents, regimens and routes of administration. We investigated the association between the use of different types of MHT and breast cancer risk in the EPIC cohort study. The analysis is based on data from 133,744 postmenopausal women. Approximately 133,744 postmenopausal women contributed to this analysis. Information on MHT was derived from country‐specific self‐administered questionnaires with a single baseline assessment. Incident breast cancers were identified through population cancer registries or by active follow‐up (mean: 8.6 yr). Overall relative risks (RR) and 95% confidence interval (CI) were derived from country‐specific Cox proportional hazard models estimates. A total of 4312 primary breast cancers were diagnosed during 1,153,747 person‐years of follow‐up. Compared with MHT never users, breast cancer risk was higher among current users of estrogen only (RR: 1.42, 95% CI 1.23–1.64) and higher still among current users of combined MHT (RR: 1.77, 95% CI 1.40–2.24; p = 0.02 for combined vs . estrogen‐only). Continuous combined regimens conferred a 43% (95% CI: 19–72%) greater risk compared with sequential regimens. There was no significant difference between progesterone and testosterone derivatives in sequential regimens. There was no significant variation in risk linked to the estrogenic component of MHT, neither for oral vs . cutaneous administration nor for estradiol compounds vs . conjugated equine estrogens. Estrogen‐only and combined MHT uses were associated with increased breast cancer risk. Continuous combined preparations were associated with the highest risk. Further studies are needed to disentangle the effects of the regimen and the progestin component.