Raloxifene reduces risk of vertebral fractures [corrected] in postmenopausal women regardless of prior hormone therapy.
OBJECTIVE
We examined whether past use of hormone therapy influences the effects of raloxifene on the risk of new vertebral fracture, cardiovascular events, or breast cancer.


METHODS
The Multiple Outcomes of Raloxifene Evaluation (MORE) trial examined vertebral fracture incidence as the primary endpoint, breast cancer incidence as a secondary endpoint. Cardiovascular events were collected as secondary safety endpoints.


METHODS
The MORE trial enrolled 7705 postmenopausal women. Of the 7682 women who reported their previous HT use status, 29% used HT before screening.


METHODS
Separate logistic regression models analyzed the relationships between prior HT use and the risk of vertebral fracture, cardiovascular events, or breast cancer. Interaction terms with P<.10 were considered to be statistically significant. Confidence intervals for relative risks (RR) were calculated using the Mantel-Haenszel method.


RESULTS
Raloxifene 60 mg/d, the clinically approved dose for osteoporosis prevention and treatment, reduced the risk of vertebral fractures by 54% (RR=0.46) and 29% (RR=0.71) in women with and without prior HT use, respectively (interaction P=.05). A lower incidence of invasive breast cancer in women with prior HT use (RR=0.23) and in women without prior HT use [RR=0.31; interaction P=.60] was observed in women receiving raloxifene (pooled doses). Irrespective of prior HT use, women treated with raloxifene (pooled doses) had no change in incidence of cardiovascular events (interaction P=.56).


CONCLUSIONS
The risk of vertebral fractures was lower in women treated with raloxifene, regardless of prior HT use, but there was a suggestion that the effect was greater in women who had used HT. Women randomized to receive raloxifene exhibited a decreased incidence of invasive breast cancer, compared with women receiving placebo. No change occurred in the incidence of cardiovascular events, regardless of prior HT use.
Johnell
Olaf
O
Department of Orthopedics, Universitetssjukhuset MAS, SE-20502 Malmo, Sweden. olof.johnell@orto.mas.lu.se
Cauley
Jane A
JA
Kulkarni
Pandurang M
PM
Wong
Mayme
M
Stock
John L
JL
D000328:Adult; D000368:Aged; D015519:Bone Density; D001943:Breast Neoplasms / Q000517:prevention & control*; D002318:Cardiovascular Diseases / Q000453:epidemiology; D002561:Cerebrovascular Disorders / Q000453:epidemiology; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000150:complications / Q000188:drug therapy*; D020849:Raloxifene Hydrochloride / Q000627:therapeutic use*; D012306:Risk; D020845:Selective Estrogen Receptor Modulators / Q000627:therapeutic use*; D016103:Spinal Fractures / Q000209:etiology / Q000517:prevention & control*
D020845:Selective Estrogen Receptor Modulators; D020849:Raloxifene Hydrochloride