On February 3, 2015, the FDA granted accelerated approval to palbociclib (IBRANCE, Pfizer Inc.), an inhibitor of cyclin-dependent kinases 4 and 6 (CDK4 and CDK6), for use in combination with letrozole for the treatment of postmenopausal women with estrogen receptor (ER)-positive, HER2-negative advanced breast cancer as initial endocrine-based therapy for their metastatic disease. The approval i...

Letrozole (Femara; Novartis Pharmaceuticals Corp., East Hanover, NJ) is a nonsteroidal inhibitor of aromatase enzyme complex. It inhibits the peripheral conversion of circulating androgens to estrogens. In postmenopausal women, letrozole decreases plasma concentrations of estradiol, estrone, and estrone sulfate by 75–95% from baseline with maximal suppression achieved within 2–3 days of treatme...

BACKGROUND Biomarkers to optimize extended adjuvant endocrine therapy for women with estrogen receptor (ER)-positive breast cancer are limited. The HOXB13/IL17BR (H/I) biomarker predicts recurrence risk in ER-positive, lymph node-negative breast cancer patients. H/I was evaluated in MA.17 trial for prognostic performance for late recurrence and treatment benefit from extended adjuvant letrozole...

We present data that letrozole, an extensively used aromatase inhibitor in the treatment of estrogen receptor-positive breast tumors in postmenopausal women, may be potentially used in the treatment of glioblastomas. First, we measured the in vitro cytotoxicity of letrozole and aromatase (CYP19A1) expression and activity in human LN229, T98G, U373MG, U251MG, and U87MG, and rat C6 glioma cell li...

Recent randomized clinical trials (RCT) comparing anastrozole (Arimidex) and letrozole (Femara) to tamoxifen in the first-line treatment of postmenopausal women with advanced hormone-sensitive breast cancer have demonstrated that both agents were at least as effective as tamoxifen. In addition, one RCT has revealed significant superiority of letrozole to tamoxifen with regard to tumor response ...

BACKGROUND Endocrine therapy is one of the standard treatments for estrogen-receptor-positive breast cancer patients. Letrozole is the only aromatase inhibitor (AI) included in Thailand's essential drug list since the change of reimbursement policy in 2008, when patients had to change their AIs (other than letrozole) to letrozole. This study aimed to prove that the efficacy of anastrozole plus ...

BACKGROUND Polycystic ovary syndrome (PCOS) is the most common cause of infrequent periods (oligomenorrhoea) and absence of periods (amenorrhoea). It affects about 4% to 8% of women worldwide and often leads to anovulatory subfertility. Aromatase inhibitors (AIs) are a novel class of drugs that were introduced for ovulation induction in 2001. Over the last ten years clinical trials have reached...

Objective: To compare the effects of letrozole 5mg and clomiphene citrate (CC) 100mg on total follicle number, endometrial thickness, hormone levels, pregnancy, miscarriage and OHSS rate in women undergoing superovulation and I.U.I. Material and methods: This study was done as a prospective randomized trial in Research and Clinical Center for Infertility (Shahid Sadoughi University) and Mother ...

STUDY QUESTION What is the effect of letrozole on the expression of steroid receptors in the placentae in cases of termination of pregnancies? SUMMARY ANSWER The expression of estrogen receptor-α (ERα) and progesterone receptor (PR) transcripts, as well as ERα protein, in placentae was suppressed by letrozole pretreatment in second trimester termination of pregnancy. WHAT IS KNOWN ALREADY T...

Aromatase inhibitors (AIs) have been used as adjuvant therapeutic agents for breast cancer. Their adverse side effect on blood lipid is well documented. Some natural compounds have been shown to be potential AIs. In the present study, we compared the efficacy of the flavonoid luteolin to the clinically approved AI letrozole (Femara; Novartis Pharmaceuticals, East Hanover, NJ) in a cell and a mo...