Use of different postmenopausal hormone therapies and risk of histology- and hormone receptor-defined invasive breast cancer.
OBJECTIVE
We previously found that the risk of invasive breast cancer varied according to the progestagen component of combined postmenopausal hormone therapy (CHT): progesterone, dydrogesterone, or other progestagens. We conducted the present study to assess how these CHTs were associated with histology- and hormone receptor-defined breast cancer.


METHODS
We used data from the French E3N cohort study, with 80,391 postmenopausal women followed for a mean duration of 8.1 years; 2,265 histologically confirmed invasive breast cancers were identified through biennial self-administered questionnaires completed from 1990 to 2002. The relative risks (RRs) were estimated using Cox proportional hazards models.


RESULTS
Compared with postmenopausal hormone therapy (HT) never-use, ever-use of estrogen+progesterone was not significantly associated with the risk of any breast cancer subtype, but increasing duration of estrogen+progesterone was associated with increasing risks of lobular (P = .06) and estrogen receptor-positive/progesterone receptor-negative (ER+/PR-; P = .02). Estrogen+dydrogesterone was associated with a significant increase in risk of lobular carcinoma (RR, 1.7; 95% CI, 1.1 to 2.6). Estrogen+other progestagens was associated with significant increases in risk of ductal and lobular carcinomas (RR, 1.6; 95% CI, 1.3 to 1.8; and 2.0; 95% CI, 1.5 to 2.7, respectively), of ER+/PR+ and ER+/PR- carcinomas (RR, 1.8; 95% CI, 1.5 to 2.1; and 2.6; 95% CI, 1.9 to 3.5, respectively), but not of ER-/PR+ or ER-/PR- carcinomas (RR, 1.0; 95% CI, 0.5 to 2.1; and 1.4; 95% CI, 0.9 to 2.0, respectively).


CONCLUSIONS
The increase in risk of breast cancer observed with the use of CHTs other than estrogen+progesterone and estrogen+dydrogesterone seems to apply preferentially to ER+ carcinomas, especially those ER+/PR-, and to affect both ductal and lobular carcinomas.
Fournier
Agnès
A
Institut National de la Santé et de la Recherche Médicale, ERI 20, EA 4045, Institut Gustave Roussy, 94805 Villejuif Cedex, France.
Fabre
Alban
A
Mesrine
Sylvie
S
Boutron-Ruault
Marie-Christine
MC
Berrino
Franco
F
Clavel-Chapelon
Françoise
F
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D018275:Carcinoma, Lobular / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D015331:Cohort Studies; D004394:Dydrogesterone / Q000627:therapeutic use*; D004967:Estrogens / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause; D011374:Progesterone / Q000627:therapeutic use*; D011372:Progestins / Q000627:therapeutic use*; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D012307:Risk Factors; D018426:SEER Program
D004967:Estrogens; D011372:Progestins; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D011374:Progesterone; D004394:Dydrogesterone