Toremifene citrate is a selective estrogen receptor modulator (SERM), a class of research chemicals that exhibits affinity for estrogen receptors but does not have estrogenic activity at the receptor, thereby limiting many of the physiological effects of estrogen.Toremifene is approved under the brand name Fareston for advanced metastatic breast cancer in the USA, and is in trials for approval for use as a prostate cancer preventative under the name Acapodene.
Toremifene and tamoxifen, for different reasons, may be useful in treating cardiovascular disease, as revealed in a Japanese study of early-strage breast cancer treatment via SERMs:
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.
Lewis et al concluded from their observations that tamoxifen and toremifene are roughly equally effective in treating breast cancer:
Fareston (toremifene) and tamoxifen, both selective estrogen receptor modulators, are therapeutically equivalent treatments for metastatic breast cancer. We hypothesized that toremifene as compared with tamoxifen given as adjuvant therapy for early stage breast cancer would result in equivalent survival with an improved side effect profile, therefore, providing superior therapeutic efficacy. …Women treated with adjuvant hormonal therapy enjoyed excellent DFS and OS. No significant differences were found between treatment with either tamoxifen or toremifene. Treatment of HR-positive patients with either tamoxifen or toremifene is appropriate.
Tsourdi, comparing 20mg tamoxifen with 80mg toremifene and an equivalent dose of raloxifene, concluded that in treating idiopathic oligozoospermia, tamoxifen and toremifene are roughly equally effective but raloxifene is not.:
The antiestrogenic effects of SERMs at the hypothalamic level result in a statistically significant increase of gonadotropin levels, which is more marked for tamoxifen and toremifene compared with raloxifene.
Another study designed by Farmakiotis et al to “evaluate whether toremifene, a selective estrogen receptor modulator (SERM), has a beneficiary effect on all three main sperm parameters” concluded:
Toremifene administration for a period of 3 months in men with idiopathic oligozoospermia is associated with significant improvements of sperm count, motility, and morphology, mediated by increased gonadotropin secretion and possibly a direct beneficial effect of toremifene on the testes. The above findings are also indicative of a better testicular exocrine (improved sperm parameters) response to treatment in men whose partners achieved pregnancy compared with those who did not. Further randomized, placebo-controlled trials should be conducted to determine whether this particular selective estrogen receptor modulator can be useful as an initial approach in men with oligozoospermia.
Taneja et al write that toremifene has “shown promise in reducing fracture risk in [prostate cancer patients who are receiving androgen deprivation therapy who are at risk of bone issues].”
On the same topic, Egerdie and Saad write:
Osteoporosis and bone fractures are frequently overlooked complications of androgen deprivation therapy in men with nonmetastatic prostate cancer. All such patients should have their bone mineral density (BMD) monitored and be offered preventive measures, such as calcium and vitamin D supplementation; patients with low BMD should be offered treatment. Several agents, including bisphosphonates, are available (although this use is currently off-label), and upcoming treatments, such as denosumab and toremifene, have shown promise in reducing fracture risk in these patients.
On the topic of prostate cancer prevention, a fairly novel concept, Fitzpatrick et al write:
The long latency period, high disease prevalence, and significant associated morbidity and mortality make prostate cancer a suitable target for a risk-reduction approach. Several agents are under investigation for reducing the risk of prostate cancer, including selenium/vitamin E and selective oestrogen receptors modulators (e.g. toremifene). In addition, the Reduction by Dutasteride of Prostate Cancer Events trial, involving >8000 men, is evaluating the effect of the dual 5AR inhibitor, dutasteride, on the risk of developing prostate cancer. A successful risk-reduction strategy might decrease the incidence of the disease, as well as the anxiety, cost and morbidity associated with its diagnosis and treatment.
Price N, Sartor O, Hutson T, Mariani S. Role of 5a-reductase inhibitors and selective estrogen receptor modulators as potential chemopreventive agents for prostate cancer. Clin Prostate Cancer 2005;3:211-4.
Tominaga T, Kimijima I, Kimura M, Takatsuka Y, Takashima S, Nomura Y, Kasumi F, Yamaguchi A, Masuda N, Noguchi S, Eshima N. Effects of Toremifene and Tamoxifen on Lipid Profiles in Post-menopausal Patients with Early Breast Cancer: Interim Results from a Japanese Phase III Trial. Jpn J Clin Oncol. 2010 Apr 8.
Lewis JD, Chagpar AB, Shaughnessy EA, Nurko J, McMasters K, Edwards MJ. Excellent outcomes with adjuvant toremifene or tamoxifen in early stage breast cancer. Cancer. 2010 May 15;116(10):2307-15.
Tsourdi E, Kourtis A, Farmakiotis D, Katsikis I, Salmas M, Panidis D. The effect of selective estrogen receptor modulator administration on the hypothalamic-pituitary-testicular axis in men with idiopathic oligozoospermia. Fertil Steril. 2009 Apr;91(4 Suppl):1427-30.
Farmakiotis D, Farmakis C, Rousso D, Kourtis A, Katsikis I, Panidis D. The beneficial effects of toremifene administration on the hypothalamic-pituitary-testicular axis and sperm parameters in men with idiopathic oligozoospermia. Fertil Steril. 2007 Oct;88(4):847-53
Taneja SS, Smith MR, Dalton JT, Raghow S, Barnette G, Steiner M, Veverka KA. Toremifene–a promising therapy for the prevention of prostate cancer and complications of androgen deprivation therapy. Expert Opin Investig Drugs. 2006 Mar;15(3):293-305.
Egerdie B, Saad F. Bone health in the prostate cancer patient receiving androgen deprivation therapy: a review of present and future management options. Can Urol Assoc J. 2010 Apr;4(2):129-35.
Fitzpatrick JM, Schulman C, Zlotta AR, Schröder FH. Prostate cancer: a serious disease suitable for prevention. BJU Int. 2009 Apr;103(7):864-70.
*The latter article is intended for educational / informational purposes only. THIS PRODUCT IS INTENDED AS A RESEARCH CHEMICAL ONLY. This designation allows the use of research chemicals strictly for in vitro testing and laboratory experimentation only. Bodily introduction of any kind into humans or animals is strictly forbidden by law.