Effects of toremifene and tamoxifen on lipid profiles in post-menopausal patients with early breast cancer: interim results from a Japanese phase III trial.
OBJECTIVE
Toremifene and tamoxifen have been used for adjuvant therapy in post-menopausal patients with breast cancer in Japan. Dyslipidemias are common in post-menopausal women. However, limited data are available on the effects of these agents on lipid profiles in Japanese patients. The Japan Toremifene Cooperative Study Group has been conducting a Phase III randomized trial of post-menopausal patients with breast cancer. One of its secondary endpoints is to confirm the effects of these agents on serum lipid profiles.


METHODS
The subjects were post-menopausal Japanese patients who had undergone surgery for early breast cancer. Toremifene or tamoxifen was administered for 2 years. Lipid levels were measured before and up to 24 months after initiation.


RESULTS
Compared with baseline, at 24 months, the toremifene group (n = 123) showed significantly decreased total cholesterol (P < 0.001) and low-density lipoprotein cholesterol levels (P < 0.001), and significantly increased high-density lipoprotein cholesterol levels (P < 0.001). Their triglyceride levels were not affected (P = 0.677). The tamoxifen group (n = 120) also showed significantly decreased total cholesterol (P < 0.001) and low-density lipoprotein cholesterol levels (P < 0.001); no significant changes occurred in high-density lipoprotein cholesterol (P = 0.297) or triglyceride levels (P = 0.120).


CONCLUSIONS
Distinct differences between two selective estrogen receptor modulators on lipids were observed. Toremifene improved lipid profiles, particularly as an enhancer of high-density lipoprotein cholesterol. To a large extent, tamoxifen improved low-density lipoprotein cholesterol levels. The impact of these improved lipid profiles on the risk of cardiovascular diseases needs further confirmation.
Tominaga
Takeshi
T
Breast Cancer Center, Toyosu Hospital, Showa University, Tokyo, Japan. t-tominaga@hkg.odn.ne.jp
Kimijima
Izo
I
Kimura
Morihiko
M
Takatsuka
Yuichi
Y
Takashima
Shigemitsu
S
Nomura
Yasuo
Y
Kasumi
Fujio
F
Yamaguchi
Akihiro
A
Masuda
Norikazu
N
Noguchi
Shinzaburo
S
Eshima
Nobuoki
N
D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000097:blood / Q000188:drug therapy*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D007564:Japan; D008055:Lipids / Q000097:blood*; D008875:Middle Aged; D017698:Postmenopause; D013629:Tamoxifen / Q000627:therapeutic use*; D017312:Toremifene / Q000627:therapeutic use*
D018931:Antineoplastic Agents, Hormonal; D008055:Lipids; D013629:Tamoxifen; D017312:Toremifene