Oestrogen-selective modulation of FSH and LH secretion by pituitary gland

Omega-3 fatty acids abrogates oxido-inflammatory and mitochondrial dysfunction-associated apoptotic responses in testis of tamoxifen-treated rats

BACKGROUND

Tamoxifen (TAM) is a widely used drug in patients with gynecomastia and breast cancer. TAM exerts its anticancer effects via its antiestrogenic activities. Unfortunately, TAM has been reported to exert gonadotoxic effects on male testes. Therefore, this study was designed to explore the possible associated mechanisms involved in TAM-induced testicular dysfunction and the possible ameliorative effects of omega-3 fatty acids (O3FA).

METHODOLOGY

Animals were randomly divided into control, O3FA, TAM, and TAM + O3FA. All treatment lasted for 28 days.

RESULTS

TAM exposure impaired sperm qualities (count, motility, and normal morphology) and decreased testicular 3β-HSD and 17β-HSD. It was accompanied by a decline in serum testosterone and an increase in estradiol, luteinizing and follicle-stimulating hormones. These observed alterations were associated with an increase in testicular injury markers, oxido-inflammatory response, and mitochondria-mediated apoptosis. These observed alterations were ameliorated by O3FA treatments.

CONCLUSIONS

O3FA ameliorated TAM-induced testicular dysfunction in male Wistar rats by modulating XO/UA and Nrf2/NF-kb signaling and cytochrome c-mediated apoptosis in TAM-treated rats.

Effect of anastrozole on hormone levels in postmenopausal women with early breast cancer

OBJECTIVES

The aim of this study was to investigate the influence of anastrozole on serum hormone levels in postmenopausal women with hormone receptor-positive breast cancer.

METHODS

We prospectively determined serum levels of estradiol, testosterone, dehydroepiandrosterone sulfate (DHEAS), sex hormone binding globulin (SHBG), follicle stimulating hormone (FSH) and luteinizing hormone (LH) at screening, as well as after 12 and 24 months of treatment and studied the associations with markers of bone turnover and bone mineral density (BMD).

RESULTS

Altogether, a full set of hormone levels was available for 70 patients. Anastrozole treatment led to decreases of 92.1% for estradiol and 11.1% for LH over the observation period (p < 0.001). Conversely, FSH, DHEAS and testosterone concentrations increased by 5.9%, 33.3% and 50%, respectively (p < 0.001). SHBG levels remained stable during the 24 months of treatment (p = 0.355). There were modest associations between FSH, SHBG, CrossLaps and N-terminal propeptide of human procollagen type I (p < 0.05). Moreover, SHBG correlated positively with the BMD of femoral neck, total hip, total hip T-score, lumbar spine and the lumbar spine T-score, whereas FSH and estradiol correlated with the lumbar spine T-score (p < 0.05).

CONCLUSIONS

During the 24 months of follow-up, treatment with anastrozole decreased the serum levels of estradiol and LH. Furthermore, we found notable increases of serum levels of FSH, DHEAS and testosterone in the first 12 months of treatment, stabilizing thereafter. Additionally, we were able to correlate hormone levels with markers of bone turnover and BMD for the first time in this regard.

Effects of exemestane and tamoxifen on hormone levels within the Tamoxifen Exemestane Adjuvant Multicentre (TEAM) trial: results of a German substudy

AIM

The aim of this study was to compare the effects of exemestane and tamoxifen on hormone levels in postmenopausal patients with hormone receptor-positive breast cancer within a Germany substudy of the Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial.

METHODS

Within the TEAM trial, patients were randomized to receive adjuvant treatment with exemestane for 5 years or tamoxifen for 2.5-3 years followed by exemestane for 2-2.5 years. Serum levels of testosterone, dehydroepiandrosterone sulfate (DHEAS), sex hormone binding globulin (SHBG), follicle stimulating hormone (FSH) and parathyroid hormone (PTH)-intact were measured at screening and after 3, 6 and 12 months of treatment.

RESULTS

Data on hormone levels were available from 63 patients in the tamoxifen arm and 68 patients in the exemestane arm. Treatment with exemestane resulted in decreases from baseline in SHBG and PTH-intact levels, and increases from baseline in testosterone, DHEAS and FSH levels. Tamoxifen treatment resulted in increases from baseline in SHBG and PTH-intact, whereas levels of testosterone and FSH decreased and DHEAS levels did not change. At all time points assessed, the absolute change from baseline was significantly different between tamoxifen and exemestane for testosterone, SHBG, FSH and PTH-intact (all p < 0.0001).

CONCLUSIONS

Exemestane and tamoxifen had statistically significantly different effects on hormone levels, including testosterone, SHBG, FSH and PTH-intact.