Effects of tamoxifen on Doppler velocimetry parameters of periurethral vessels in postmenopausal women

Effects of tamoxifen on urinary incontinence: Case report and review of literature

RATIONALE

Tamoxifen has been used in women with hormone receptor-positive breast cancer and has been shown to successfully reduce both recurrence and mortality. On the contrary, long-term use of tamoxifen has hormone-related urogenital side effects which decrease the quality of life of the patients.

PATIENT CONCERNS

In this case report, we present a breast cancer patient receiving tamoxifen who developed urinary incontinence; we discuss the effects of tamoxifen on urinary incontinence, which decreases quality of life of the patients who were evaluated in our clinic.

DIAGNOSES

Breast cancer, urinary incontinence.

INTERVENTIONS

Temporarily discontinuing tamoxifen.

OUTCOMES

Urinary incontinence resolved.

LESSONS

Based on the case we reported and literature, estrogen can cause a dose-dependent increase in incontinence, but more preclinical and clinical studies of both estrogen and SERMs are needed to support this notion; given the fact that some small-scale clinical studies have not proven a direct relationship between tamoxifen and urinary incontinence. We suggest that clinicians faced with the issue should temporarily stop usage of the drug once the complaint of urinary incontinence arises.

Effect of tamoxifen on extracellular signal-regulated kinases in the urethra of castrated female rats

OBJECTIVE

The aim was to evaluate the effects of tamoxifen in activating extracellular signal-regulated kinases (ERKs) 1 and 2 in the urethras of castrated female rats.

STUDY DESIGN

Twelve castrated adult female rats were divided into a control group (n=6) in which the animals received vehicle, and the experimental group (n=6) in which the rats received tamoxifen 250 μg/day by gavage for 28 days. Then, the animals were sacrificed and their urethras removed. Proteins were extracted, quantified and processed by Western blot analysis with specific phospho-ERK1 and 2 antibodies. Data were analyzed using Student's t-test (p<0.05).

RESULTS

A significant increase occurred in phospho-ERK1 levels in the experimental group compared to the control group (p<0.01), while no difference was found in phospho-ERK2 levels between the groups (p=0.313).

CONCLUSION

The present results indicate that, at the doses and during the time of treatment used, tamoxifen significantly increased phospho-ERK1 levels in the urethras of castrated female rats.

Sexual steroids in urogynecology

The decline in sex hormone levels that accompanies the menopause has substantial effects on the tissues of the urogenital system, leading to atrophic changes. These changes can have negative effects on sexual and urinary function. The authors evaluate the repercussion of hypoestrogenism and sexual steroids on some elements of the pelvic floor and lower urinary tract. They summarize their research work and review significant published papers. They emphasize the changes in urinary mucosae, periurethral vessels, muscular layer, connective tissue, gene expression, autonomic nervous system receptors, as well as the main clinical aspects involved.

Vascular endothelial growth factor expression in the urethral epithelium of castrated adult female rats treated with tamoxifen

OBJECTIVE

The aim of this study was to evaluate the effects of tamoxifen on vascular endothelial growth factor (VEGF) expression in the urethral epithelium of castrated rats.

MATERIALS AND METHODS

Thirty-six adult, castrated, female Wistar-Hannover rats were randomly divided into two groups: group I (n = 16, control), receiving only propylene glycol, and group II (n = 20, tamoxifen), treated with 250 microg/day of tamoxifen for 30 consecutive days by gavage. On the 31st day, the animals were sacrificed and the urethras were immediately removed, separated into the proximal and distal segments and processed for VEGF immunohistochemistry. The data were analysed using Student's t-test (p < 0.05).

RESULTS

The mean percentage of VEGF expression in the epithelium of the proximal urethra of the animals in groups I and II was 64.47+/-3.70 and 74.69+/-3.03, respectively (p < 0.03), whereas the mean percentage of VEGF expression in the distal urethral epithelium of the animals in groups I and II was 53.49+/-4.64 and 68.57+/-3.67, respectively (p < 0.01).

CONCLUSIONS

Our results indicate that, at the dose and during the time of treatment used, tamoxifen increased VEGF expression in the urethral epithelium of castrated rats.

Morphometric analysis of the urethra of castrated female rats treated with tamoxifen

OBJECTIVES

The aim of this study was to evaluate the effects of tamoxifen on the weight and thickness of the urethral epithelium of castrated female rats.

METHODS

Forty castrated adult female Wistar-Hannover rats were randomly divided into two groups: Group I (n=20) in which the animals received only the vehicle (propylene glycol) and Group II (n=20) in which the rats received tamoxifen 250microg/day by gavage. After 30 days of treatment, all animals were sacrificed and the urethra was immediately removed for weighing. Next, the urethra was divided into the proximal and distal segments, which were fixed in 10% formaldehyde and submitted to routine histological techniques for morphometric study. The data were analyzed using the weighted minimum mean-square error method and Student's t-test for two independent samples (p<0.05).

RESULTS

There was a significant increase in the mean weight of the urethra in the rats of Group II compared to the control group, 32.0+/-2.0mg and 22.0+/-1.6mg, respectively (p<0.001). The mean thickness of the distal urethral epithelium of the animals treated with tamoxifen was significantly greater than that of the control group, 42.8+/-2.0microm and 36.6+/-1.5microm, respectively (p<0.001). There was no statistically significant difference between the two groups with respect to the epithelial thickness of the proximal urethra (p=0.514).

CONCLUSION

Treating castrated adult rats with 250microg/day of tamoxifen for 30 days may increase the weight of the urethra and the thickness of the distal urethral epithelium.

Hormonal influence on periurethral vessels in postmenopausal incontinent women using Doppler velocimetry analysis

The lack of estrogen affects the urinary tract mainly by diminishing vascular, muscular and epithelial trophism, resulting in negative effects on continence in postmenopausal women.

OBJECTIVE

Study the effect of hormone therapy (estrogen and progesterone) in periurethral vessels detected by Doppler velocimetric analysis using, as parameters, the number of vessels, resistance and pulsatility indexes, as well as the minimum diastolic value.

METHODS

Thirty-eight postmenopausal women with stress urinary incontinence were randomized into two groups. The first consisted of women receiving 3 months of estrogen therapy previous to 3 months of continuous estrogen and progesterone combined therapy. The second comprised of women receiving 3 months of continuous estrogen and progesterone therapy. Periurethral Doppler velocimetric analysis was done before hormone administration and during treatment in both groups.

RESULTS

We observed a statistically significant increased number of periurethral vessels during treatment in both groups. There was an increase in value of the mean minimum diastolic value during estrogen and progesterone therapy in Group 2. The resistance indexes diminished in both groups. However, they were not statistically significant.

CONCLUSION

Hormonal therapy of short duration (3-6 months) had a positive effect on the urethral continence mechanism increasing the number of periurethral vessels either with estrogen alone or combined therapy (estrogen and progesterone).