Should tamoxifen users be screened for endometrial lesions?

Heterocycles in Breast Cancer Treatment: The Use of Pyrazole Derivatives

Among the aromatic heterocycle rings, pyrazole -a five-membered ring with two adjacent nitrogen atoms in its structure has been postulated as a potent candidate in the pharmacological context. This moiety is an interesting therapeutic target covering a broad spectrum of biological activities due to its presence in many natural substances. Hence, the potential of the pyrazole derivatives as antitumor agents has been explored in many investigations, showing promising results in some cases. In this sense, breast cancer, which is already the leading cause of cancer mortality in women in some countries, has been the topic selected for this review, which covers a range of different research from the earliest studies published in 2003 to the most recent ones in 2021.

Comparative Study on Hysteroscopic and Histologic Examinations of the Endometrium in Postmenopausal Women Taking Tamoxifen

Objectives

To evaluate the histologic effects of tamoxifen on the endometrium using hysteroscopy in postmenopausal women with breast cancer.

Methods

The study included 46 postmenopausal patients who were referred from another clinic due to thickening or bleeding of the endometrium after taking tamoxifen for breast cancer. All patients underwent transvaginal sonography (TVS) and hysteroscopic endometrial biopsy with a 5-mm, continuous-flow, operating hysteroscope.

Results

The incidence of malignancy was high (20%) in cases of abnormal uterine bleeding (AUB) after taking tamoxifen. However, in the non-AUB group with thick endometrium after taking tamoxifen, the incidence of adenocarcinoma was 3.2%.

Conclusions

Our findings confirm the estrogen-like effect of tamoxifen on the endometrium. Endometrial evaluation with TVS suggests further diagnostic procedures; moreover, histologic examination is necessary under hysteroscopy, especially in cases of endometrial bleeding after taking tamoxifen.

Long-term endometrial effects in postmenopausal women with early breast cancer participating in the Intergroup Exemestane Study (IES)--a randomised controlled trial of exemestane versus continued tamoxifen after 2-3 years tamoxifen

BACKGROUND

The antiestrogen tamoxifen may have partial estrogen-like effects on the postmenopausal uterus. Aromatase inhibitors (AIs) are increasingly used after initial tamoxifen in the adjuvant treatment of postmenopausal early breast cancer due to their mechanism of action: a potential benefit being a reduction of uterine abnormalities caused by tamoxifen.

PATIENTS AND METHODS

Sonographic uterine effects of the steroidal AI exemestane were studied in 219 women participating in the Intergroup Exemestane Study: a large trial in postmenopausal women with estrogen receptor-positive (or unknown) early breast cancer, disease free after 2-3 years of tamoxifen, randomly assigned to continue tamoxifen or switch to exemestane to complete 5 years adjuvant treatment. The primary end point was the proportion of patients with abnormal (> or =5 mm) endometrial thickness (ET) on transvaginal ultrasound 24 months after randomisation.

RESULTS

The analysis included 183 patients. Two years after randomisation, the proportion of patients with abnormal ET was significantly lower in the exemestane compared with tamoxifen arm (36% versus 62%, respectively; P = 0.004). This difference emerged within 6 months of switching treatment (43.5% versus 65.2%, respectively; P = 0.01) and disappeared within 12 months of treatment completion (30.8% versus 34.7%, respectively; P = 0.67).

CONCLUSION

Switching from tamoxifen to exemestane significantly reverses endometrial thickening associated with continued tamoxifen.

The effect of tamoxifen on the genital tract

Tamoxifen is a selective estrogen receptor modulator (SERM) that is widely used in the treatment of patients with breast cancer and for chemoprophylaxis in high risk women. Tamoxifen results in a spectrum of abnormalities involving the genital tract, the most significant being an increased incidence of endometrial cancer and uterine sarcoma. This article reviews the effects of tamoxifen on the genital tract and the strengths and weaknesses of various imaging modalities for evaluating the endometrium.

Endometrial safety of third generation aromatase inhibitors versus tamoxifen in breast cancer patients

The estrogenic activity of tamoxifen on the uterus increases the risk of developing benign and malignant uterine pathologies in breast cancer patients receiving this drug. This has led to gynecological interventions specifically in symptomatic women to exclude malignant disease. Given this known side effect associated with tamoxifen therapy, newer endocrine therapies such as the third-generation aromatase inhibitors have been compared to tamoxifen also in terms of their uterine effects. To date, studies that have directly compared the uterine effects of tamoxifen with that of aromatase inhibitors generally show that aromatase inhibitors such as anastrozole, letrozole, and exemestane are associated with less uterine pathologies compared to tamoxifen. Furthermore, aromatase inhibitors may even reverse uterine abnormalities induced by tamoxifen. This implies that the absence of a stimulatory effect on the uterus would be one of the benefits gained with aromatase inhibitor therapy and may decrease or even obviate the need for gynecological interventions.

Endometrial cancer

Each year, endometrial cancer develops in about 142,000 women worldwide, and an estimated 42,000 women die from this cancer. The typical age-incidence curve for endometrial cancer shows that most cases are diagnosed after the menopause, with the highest incidence around the seventh decade of life. The appearance of symptoms early in the course explains why most women with endometrial cancer have early-stage disease at presentation. For all stages taken together, the overall 5-year survival is around 80%. There is a substantial prognostic difference between the histological types of endometrial cancers. The most common lesions (type 1) are typically hormone sensitive and low stage and have an excellent prognosis, whereas tumours of type 2 are high grade with a tendency to recur, even in early stage. The cornerstone of treatment for endometrial cancer is surgery, which not only is important for staging purposes but also enables appropriate tailoring of adjuvant treatment modalities that benefit high-risk patients only. We review current concepts about epidemiology, pathology, pathogenesis, risk factors and prevention, diagnosis, staging, prognostic factors, treatment, and follow-up of endometrial cancer.

Third generation aromatase inhibitors may prevent endometrial growth and reverse tamoxifen-induced uterine changes in postmenopausal breast cancer patients

BACKGROUND

Tamoxifen may induce uterine abnormalities of clinical concern. Our aim was to compare early uterine changes occurring in postmenopausal breast cancer patients treated in first-line with tamoxifen or third generation aromatase inhibitors. We also assessed the effect of aromatase inhibitors on tamoxifen-induced uterine changes.

PATIENTS AND METHODS

Seventy-seven consecutive postmenopausal breast cancer patients scheduled to start endocrine treatment were included in this prospective study. Transvaginal ultrasonography (TVUS) was carried out before and after 3 months of therapy. No interventions were done on pre-existing asymptomatic uterine abnormalities seen on baseline sonography.

RESULTS

After 3 months of therapy, tamoxifen significantly increased endometrial thickness and uterine volume. Additionally, tamoxifen induced endometrial cysts and polyps, and increased the size of pre-existing fibroids. In contrast, aromatase inhibitors did not stimulate endometrial growth and were not associated with endometrial pathologies seen under tamoxifen. Furthermore, aromatase inhibitors decreased endometrial thickness and uterine volume in patients previously treated with tamoxifen.

CONCLUSIONS

Our study demonstrates that tamoxifen induces uterine abnormalities from as early as 3 months of therapy. In contrast, these abnormalities are not seen in patients on aromatase inhibitors. Furthermore, our data indicate that tamoxifen therapy followed by an aromatase inhibitor may lead to a reduction in endometrial pathologies associated with tamoxifen.

The effects of tamoxifen on the female genital tract

Tamoxifen is an effective and relatively non-toxic compound used in palliative and adjuvant treatment of breast cancer. More recently its preventive role in breast cancer has also been demonstrated. However, tamoxifen use is related to some increase in the risk of endometrial cancer and to a significant rise in the incidence of benign endometrial pathologies. The activity of tamoxifen against breast cancer is mainly achieved by blocking the oestrogen receptor, whereas the effect of this compound on the female genital tract is mostly related to its agonistic properties. Despite numerous studies no effective methods of tamoxifen-user surveillance have been developed and currently no active screening for endometrial cancer, apart from yearly gynaecological examination, is recommended in these patients. In other parts of the genital tract, tamoxifen increases the risk of some benign conditions and may cause difficulties in the interpretation of cervical smears. Further studies are warranted to develop more effective surveillance and methods decreasing the detrimental effects of tamoxifen on the female genital tract.

Comparison of Hysteroscopic and Hysterectomy Findings to Assess the Diagnostic Accuracy of Office Hysteroscopy in Tamoxifen-Treated Patients with Breast Cancer

STUDY OBJECTIVE

To assess the diagnostic accuracy of office hysteroscopy by comparing hysteroscopic findings with histologic findings on hysterectomy specimens in postmenopausal women with breast cancer treated with tamoxifen.

DESIGN

Retrospective clinical study (Canadian Task Force classification II-2).

SETTING

University-affiliated hospital.

PATIENTS

Thirty-three women.

INTERVENTION

Record review.

MEASUREMENTS AND MAIN RESULTS

Compared with histologic diagnoses of uteri, hysteroscopic findings showed diagnostic sensitivity of 97%, specificity of 100%, positive predictive value of 100% and negative predictive value of 96%. The diagnostic accuracy of hysteroscopy is the same in patients taking tamoxifen as in the general population.

CONCLUSION

Hysteroscopy is a powerful method for diagnosing endometrial disease because it provides a direct view of the uterine cavity, reveals focal lesions, and enables targeted biopsies to be performed at the same time.

Endometrial disorders in 406 breast cancer patients on tamoxifen: the case for less intensive monitoring

OBJECTIVES

To describe the endometrial appearance in postmenopausal breast cancer patients on tamoxifen and to assess a routine surveillance scheme for endometrial lesions.

STUDY DESIGN

Three hundred and seventeen postmenopausal breast cancer women already on tamoxifen at the start of the study (group I) and 89 breast cancer women assessed before any tamoxifen intake (group II) underwent an initial and then yearly scans with transvaginal ultrasonography, followed by an hysteroscopy and biopsy for women with an endometrium thickened above 8mm. Endometrial thickness was also measured in 823 women with no breast cancer nor tamoxifen intake (group III).

RESULTS

Initial mean endometrial thickness was 8.2mm in group I, 4.4mm in group II and 3.4mm in group III (P<0.001). Eighteen percent endometrial lesions were found in group I and 3.3% in group II. We observed a significant association between endometrial pathology and both cumulated dose and total duration. Polyps were the most frequent and first to appear pathology. Five cancers were detected in group I, and all of them had taken tamoxifen for more than 3 years.

CONCLUSION

Our surveillance scheme could be lightened; an acceptable screening scheme might include a baseline assessment before the start of tamoxifen and, if normal, yearly screening after 3 years of tamoxifen therapy, yearly surveillance for women with an abnormal baseline assessment and immediate investigation for symptomatic women.

What would be the properties of an ideal SERM?

Selective estrogen receptor modulators (SERMs) are drugs that bind to the estrogen receptor (ER); in some tissues they act like estrogen (agonists), while in other tissues they oppose the action of estrogen (antagonists). The SERM tamoxifen acts as an estrogen antagonist in the breast in that it prevents and treats breast cancer, but it acts as an estrogen agonist in the endometrium, where it can induce cancer. Estrogen, and to a lesser extent SERMs, are effective in preventing and treating osteoporosis. Contrary to the prevalent hypothesis that estrogen provides benefit to women with regard to secondary prevention of coronary heart disease (CHD), randomized clinical trials have demonstrated that estrogen is associated with an increased risk of CHD in this population of women. Conflicting results have been reported on the effect of estrogens on cognitive function. The latest and largest randomized clinical trials have demonstrated a beneficial role in short-term memory in nondemented women, in contrast to the absence of such benefit in improving symptoms in women with Alzheimer's disease. Although estrogens have been used successfully to treat some menopausal symptoms such as hot flashes, the SERMs tamoxifen and raloxifene actually induce or increase hot flashes. Data on the beneficial and adverse effects of estrogen and SERMs are reported along with an elaboration of the constellation of properties that would characterize an ideal SERM working through the ER.

Tamoxifen and the female reproductive tract

The use of tamoxifen among women with breast cancer or at high risk of the disease has greatly expanded over the past several decades. Tamoxifen has a complex effect on the female reproductive tract and several tamoxifen-associated changes have been described among tamoxifen users. These include endometrial thickening, cervical and endometrial polyps, endometrial hyperplasia, endometrial adenocarcinoma, uterine sarcoma, increase in the size of uterine leiomyomata, exacerbation of endometriosis and ovarian cysts. The most common uterine change associated with tamoxifen is endometrial polyps. The annual incidence of endometrial cancer among women on tamoxifen is 2 per 1000 and seems to be related to the cumulative tamoxifen dose. It is not clear whether endometrial cancer occurring among women on tamoxifen is of worse prognosis than endometrial cancer occurring among women not receiving tamoxifen. Tamoxifen is associated with several sonographic changes which make the use of ultrasound in surveillance of these patients difficult. There is no indication to implement routine screening for endometrial cancer among all women on tamoxifen. However, endometrial biopsy, preferably via hysteroscopy, should be considered in women with uterine bleeding.

Endometrial evaluation with transvaginal US and hysterosonography in asymptomatic postmenopausal women with breast cancer receiving tamoxifen

PURPOSE

To determine performance characteristics of transvaginal ultrasonography (US) and hysterosonography for diagnosing endometrial abnormality in asymptomatic postmenopausal women with breast cancer receiving tamoxifen.

MATERIALS AND METHODS

The authors prospectively examined 138 women receiving tamoxifen by using transvaginal US, hysterosonography, and office hysteroscopy. The combined hysteroscopic-histopathologic diagnosis was the reference standard. Sensitivity, specificity, positive and negative predictive values, and likelihood ratios of transvaginal US and hysterosonography were calculated.

RESULTS

All 138 women underwent transvaginal US; 104, successful hysterosonography; and 117, successful hysteroscopy. Uterine abnormality was present in 47 (40.2%) of 117 women: 45 with polyps and two with submucosal fibroids. Receiver operating characteristic curve analysis revealed 6 mm to be the optimal endometrial thickness cutoff for diagnosing endometrial abnormalities. When a thickness greater than 6 mm or a focal endometrial finding was considered abnormal, transvaginal US had a sensitivity of 85.1% and a specificity of 55.7%. In 92 women who completed transvaginal US, hysterosonography, and hysteroscopy, hysterosonography was more specific (79.2%; P =.008) but not significantly more sensitive (89.7%; P =.508) than transvaginal US. When women with abnormal transvaginal US findings were further examined with hysterosonography, the sequential combination of transvaginal US and hysterosonography was more specific (77.1%) than transvaginal US alone (P <.001), without a significant decrease in sensitivity (78.7%; P =.25).

CONCLUSION

In asymptomatic postmenopausal women receiving tamoxifen, 6 mm is the optimal endometrial thickness cutoff for diagnosing endometrial abnormalities with transvaginal US. Further examination with hysterosonography can improve specificity by reducing the high false-positive rate of transvaginal US.

Tamoxifen, screening and new oestrogen receptor modulators

Tamoxifen is a selective oestrogen receptor modulator (SERM) with anti-oestrogenic properties in the breast and oestrogenic effects in tissues such as bone and the cardiovascular system. It is an excellent breast cancer drug for all stages of the disease. Its SERM profile makes it a valuable alternative to hormone replacement therapy, especially for women at high risk of breast cancer. Tamoxifen, however, increases the incidence of benign and malignant lesions of the uterus. Secondary prevention of these, early detection and treatment, is feasible but not cost-effective in breast cancer patients because potential endometrial risks do not outweigh beneficial effects in the breast. This may be different in healthy women with an as yet unknown benefit on breast cancer mortality. We review the literature on the importance of tamoxifen's endometrial lesions and balance available evidence on whether and how best to screen them. In a subset of tamoxifen users it seems advisable to assess the uterine cavity prior to intake with a yearly endometrial assessment as pointed out, starting 3 years after initiation of treatment. In most cases there is endometrial thickening on ultrasonographic assessment and additional tests such as hydrosonography or hysteroscopy are required to confirm an empty atrophic uterus as remains the case in most asymptomatic women on tamoxifen. Newer compounds, such as raloxifene, have a similar SERM profile to tamoxifen but are neutral on the uterus. This has recently been proven by 3 years of endometrial follow-up data. Longer endometrial safety will hopefully confirm these early findings. Whether other SERMs in development are better, and which of them is better for the breast, is to be demonstrated in ongoing studies.

Endometrial protection from tamoxifen-stimulated changes by a levonorgestrel-releasing intrauterine system: a randomised controlled trial

INTRODUCTION

Tamoxifen is currently the most commonly used adjuvant treatment for breast cancer, however, it frequently causes episodes of unscheduled uterine bleeding, which could be associated with proliferative changes of the endometrium, or even endometrial cancer. We aimed to assess whether a levonorgestrel intrauterine system could modulate the uterine responses to tamoxifen. We also aimed to assess women's tolerance of the screening procedures, the insertion, removal, and potential side-effects of the device.

METHODS

We did a randomised controlled trial, in which postmenopausal women who had had at least 1 year of adjuvant tamoxifen treatment and who were undergoing regular follow-up for breast cancer were randomly assigned to either endometrial surveillance alone, or endometrial surveillance before and after insertion of the levonorgestrel intrauterine system for 12 months. We assessed tolerance of the surveillance procedures and the device with visual analogue scales.

FINDINGS

Baseline assessment showed only benign uterine changes in all women (n=122). Hysteroscopic assessment indicated a uniform decidual response (confirmed histologically in 40 of 41 cases) in all women fitted with the intrauterine system; there were no new polyps in these women and 13% had fewer fibroids than in controls. Both screening procedures and device were well tolerated. There was an excess of bleeding in the women fitted with intrauterine systems but this resolved to a baseline similar to those receiving surveillance only.

INTERPRETATION

The levonorgestrel-releasing intrauterine system had a protective action against the uterine effects of tamoxifen. The effectiveness of this device in preventing uterine changes in the endometrium needs to be assessed in the context of decreasing the need for repeated investigations of postmenopausal bleeding in women taking tamoxifen.

Effects of adjuvant tamoxifen on the endometrium in postmenopausal women with breast cancer: a prospective long-term study using transvaginal ultrasound

PURPOSE

To study the value of transvaginal ultrasound (TVS) in endometrial screening of postmenopausal breast cancer patients treated with tamoxifen.

PATIENTS AND METHODS

In 247 tamoxifen-treated (20 to 30 mg/d for >/= 2 years) women and 98 controls, the endometrium was prospectively followed-up by means of TVS every 6 months for up to 5 years. Patients with homogeneous endometrium of more than 10-mm thickness were then scanned repeatedly every 3 months.

RESULTS

The mean endometrial thickness was 3.5 +/- 1.1 mm before treatment and increased to a maximum of 9. 2 +/- 5.1 mm after 3 years of tamoxifen application (P: <.0001), which was significantly (P: <.0001) thicker compared with controls. Fifty-two asymptomatic patients with thickened or morphologically suspect endometrium underwent hysteroscopy and dilatation and curettage (D&C), resulting in four uterine perforations. Histopathologically, atrophy was found in 38 patients (73.1%), polyps in nine, hyperplasia in four, and endometrial cancer in one case. In 20 screened patients who reported vaginal bleeding, five atrophies (25%), five polyps, four hyperplasias, and two endometrial cancers were found. Before hysteroscopy and D&C were performed, 36 (69.2%) of 52 asymptomatic and four (20%) of 20 symptomatic patients were scanned by repeated TVS over 2 to 30 months. Invasive diagnostic procedures were significantly (P: <.05) more frequent in younger and obese patients. In the controls, one asymptomatic polyp and one symptomatic hyperplasia were found.

CONCLUSION

In tamoxifen-treated patients, TVS offered a high false-positive rate, even with a cutoff value of 10 mm for endometrial thickness and repeated TVS scans. Increased iatrogenic morbidity and only one asymptomatic endometrial carcinoma do not warrant endometrial screening by TVS in tamoxifen-treated patients.

Uterine side effects of treatment with tamoxifen

OBJECTIVE

To assess a causal the relationship between endometrial lesions and tamoxifen therapy in patients with breast cancer.

DESIGN

Prospective longitudinal study and cross-sectional study.

SETTING

Cancer prevention unit at Basurto Hospital, Bilbao.

POPULATION AND METHODS

Three populations of breast cancer were studied: 43 before the beginning of tamoxifen; 78 after 5-72 months of tamoxifen, and 34 before tamoxifen and after 12-24 months of tamoxifen treatment (PAIRED GROUP). All of them were systematically studied with CO(2) diagnostic hysteroscopy and endometrial biopsy by the same clinician.

RESULTS

Before tamoxifen, the following endometrial lesions were detected: endometrial polyps 9.3%; endometrial cysts 16.3%; synechiae 11.6%. In the paired group the ingestion of tamoxifen shows a direct causal effect with a significant increase in endometrial polyps (11.8% vs. 29.4%; OR=13; CI=7.9-18.1), in endometrial cysts (17.7% vs. 55.9%; OR=7.5; CI=5. 9-9.1) and in synechiae (14.7% vs. 35.5%; OR=8; CI=4.7-11.3). In the group under tamoxifen for 5-72 months, one endometrial carcinoma was detected.

CONCLUSIONS

Breast cancer patients have a number of endometrial lesions before undergoing any hormonal therapy. Tamoxifen significantly increased benign endometrial lesions, usually after less than one year of treatment. No cases of endometrial carcinoma was found in our series of 34 patients with 1-2 years of tamoxifen treatment, and 1/78 in patients with 5-72 months of tamoxifen.

Ultrasound assessment of the endometrium in healthy, asymptomatic early post-menopausal women: saline infusion sonohysterography versus transvaginal ultrasound

OBJECTIVE

To exclude pre-existing endometrial pathology in asymptomatic early post-menopausal women before starting hormone replacement therapy by transvaginal ultrasound (TVS) and saline infusion sonohysterography (SIS).

METHODS

In a cross-sectional study, 148 healthy women (mean age, 51.1 years; range, 46-59 years) underwent ultrasound evaluation of the endometrium before participation in a clinical trial. TVS was used to measure double-layer endometrial thickness. SIS was performed at the same visit to measure anterior and posterior single-layer endometrial thickness, and to identify endometrial abnormalities when present. Ultrasound results were defined as informative if the endometrium could be adequately visualized. Findings on TVSs were defined as abnormal if a double-layer endometrial measurement > 5.0 mm was obtained. Findings on SIS were defined as abnormal if one or both single layers of the endometrium measured > 2.5 mm, or if focal endometrial thickening or a polyp was present.

RESULTS

Of the 148 eligible women, informative TVS results were obtained from 134 women, SIS results from 133 women and both procedures combined from 119 women. TVS scans gave abnormal results in 8.2% of women (11 of 134) and SIS gave abnormal results in 36.8% of women (49 of 133). Of the 14 women with a non-informative TVS, eight had abnormal SIS results. Of the 15 women with a non-informative SIS, three had abnormal TVS results. In the 119 women with both informative TVS and SIS, abnormal TVS scans were found in 6.7% of women (eight of 119) and abnormal SIS in 34.5% of women (41 of 119). All eight women with abnormal TVS had an abnormal SIS, whereas 29.7% (33 of 111) of the women with a normal TVS had an abnormal SIS.

CONCLUSIONS

Ultrasound evaluation demonstrated endometrial abnormalities in 34.5% (41 of 119) of asymptomatic post-menopausal women. SIS is more accurate than TVS in the detection of endometrial abnormalities.

Limited value of sonohysterography for endometrial screening in asymptomatic, postmenopausal patients treated with tamoxifen

OBJECTIVES

Sonohysterography (SHG) has been proposed as a useful tool for the surveillance of the endometrium in patients receiving tamoxifen. This study aimed to assess the value of SHG in asymptomatic patients who would have been biopsy candidates because of abnormal transvaginal ultrasound (TVUS) results.

METHODS

The study population included postmenopausal breast cancer patients receiving adjuvant tamoxifen who had asymptomatic abnormalities at TVUS (endometrial thickness >/=8 mm or endometrial echo not adequately visualized). SHG was performed with an Aloka SSD 680 system using a 5-MHz vaginal probe, with sterile saline solution as contrast medium.

RESULTS

Forty-one patients entered the study. A regular endometrial echo was identified by SHG in 9 patients (21.9%). Histology was obtained in the remaining 32 patients with positive (n = 27, 65.8%) or unsuccessful (n = 5, 12.2%) SHG. Benign polyps (n = 15, 36.6%) and endometrial atrophy (n = 14, 34.1%) were the most common findings; 3 patients (7.3%) had simple hyperplasia.

CONCLUSIONS

Breast cancer patients with asymptomatic, tamoxifen-associated TVUS abnormalities have little additional benefit from SHG. More than 23 remain candidates for biopsy, which usually yields benign or insignificant findings.

Hysteroscopic evaluation of the endometrium in postmenopausal women taking tamoxifen

STUDY OBJECTIVE

To evaluate hysteroscopic endometrial changes due to tamoxifen therapy in postmenopausal women with breast cancer.

DESIGN

Retrospective study (Canadian Task Force classification II-2).

SETTING

University-affiliated hospital. Patients. Eighty-eight postmenopausal women (or with iatrogenic amenorrhea) receiving tamoxifen 20 mg/day for at least 1 year for breast cancer.

INTERVENTION

Record review of patients undergoing transvaginal sonography (TVS) and office hysteroscopy with eye-directed biopsy specimens obtained with a 5-mm, continuous-flow, operative hysteroscope.

MEASUREMENTS AND MAIN RESULTS

Patients with thickened endometrium and pathologic findings at hysteroscopy had taken tamoxifen for significantly longer times than those without such findings (p < 0.05).

CONCLUSION

Our findings confirm the estrogenic effect of tamoxifen on endometrium. Endometrial evaluation by TVS suggests further diagnostic procedures, but only hysteroscopy allows the surgeon to visualize endometrial lesions and obtain eye-directed biopsy tissue.

Factors implicated in the decision whether or not to join the tamoxifen trial in women at high familial risk of breast cancer

Why, given similar medical circumstances-high familial risk of breast cancer-will some women elect to join a trial of drugs designed to reduce that risk but others choose not to take part? The aim of this study was to identify measurable differences between women who elect to join a placebo-controlled, double-blind randomised trial of the drug tamoxifen and women who elect not to join. One hundred and six women attending a breast care clinic completed questionnaires covering demographic details, health locus of control, perception of risk and adequacy of medical communication. All were eligible for inclusion in the tamoxifen trial. Only half (n=53) of the sample elected to join, the other half (n=53) declined. Those who declined the trial were significantly more aware of lifestyle factors thought to influence the development of cancers-diet, exercise and oestrogen-prolonging activities (p<0.001), and they also appeared to find the information given by the hospital about tamoxifen harder to understand than did the group who had joined the trial (p=0.01). They could think of significantly fewer positive reasons for joining (p<0.001) and were significantly younger (p=0.001). Participants in both groups significantly overestimated the relative risks of breast cancer. The average estimation of risk for women aged 30 with a family history of breast cancer was 22 times higher than that given by their consultant. This gives rise to considerable concerns about the information underpinning informed consent.

Sonographic, hysteroscopic, and histologic evaluation of the endometrium in postmenopausal women with breast cancer receiving tamoxifen

STUDY OBJECTIVE

To evaluate the estrogenic effects of tamoxifen on the endometrium in postmenopausal women with breast cancer.

DESIGN

Consecutive study (Canadian Task Force classification II-2).

SETTING

University-affiliated hospital.

PATIENTS

Thirty-three women. Interventions. All patients underwent transvaginal sonography (TVS) and color flow Doppler of endometrial vessels, hysteroscopy, and, if necessary, endometrial biopsy or other operative hysteroscopic procedures.

MEASUREMENTS AND MAIN RESULTS

In four women the endometrium was thin on TVS and atrophic at hysteroscopic assessment. In 29 women with thick endometrium on TVS, hysteroscopy and endometrial biopsy showed atrophy (11 patients), hyperplasia (5), polyps (11), and well-differentiated adenocarcinoma (2). The two endometrial cancers were present in women with uterine bleeding. In women with positive histologic findings, the endometrium was significantly thicker (p = 0.04) and duration of tamoxifen therapy longer than in those with negative findings, although this was not statistically significant (p = 0.067).

CONCLUSION

We believe regular assessment of the endometrium by TVS should be performed in postmenopausal patients at the start of the tamoxifen therapy, and hysteroscopy in women with a thick endometrium or postmenopausal bleeding. We believe that patients with thin endometrium on TVS at the beginning of tamoxifen therapy, who have no abnormal uterine bleeding should be screened with these examinations for 2 years.

Guidelines for monitoring patients taking tamoxifen treatment

Tamoxifen is the most important anti-breast cancer drug in clinical use and has the potential to be used as a chemopreventive breast cancer agent. Using outpatient hysteroscopy and based on 2 case control and 2 cohort follow-up studies in our department, we were able to demonstrate that 50% of women receiving long term tamoxifen experienced some sort of adverse endometrial effects. Although many women retain an atrophic endometrial layer, tamoxifen intake can lead to extensive senile cystic atrophia of the human endometrium, to endometrial hyperplasia and to endometrial polyp formation. Based on a critical review of the literature, we have shown that tamoxifen doubles the risk for developing endometrial cancer in postmenopausal women, although this increased risk may be higher and is duration (i.e. time of use)-dependent. Screening patients with breast cancer for endometrial abnormalities while they are taking tamoxifen is feasible and uterine morbidity related to tamoxifen intake is preventable. Although screening may increase drug compliance it may not be cost-beneficial. However, uterine safety becomes important when only a small benefit of the treatment is to be expected as in the use of tamoxifen in healthy women for breast cancer prevention. The aim of this report is to discuss methods and guidelines for detecting endometrial adverse effects of tamoxifen and to provide the clinician with a current opinion on timing and frequency of screening patients taking tamoxifen for the development of endometrial cancer. In summary, those who advocate screening should start with pretreatment uterine assessment using transvaginal ultrasonography or outpatient hysteroscopy. Symptom-free women with a normal pretreatment uterine cavity can be screened annually with transvaginal sonography from 2 to 3 years after the start of tamoxifen. Hysteroscopy or saline infusion sonography will be required if there is endometrial thickening because the only value of transvaginal ultrasonography is a normal finding being a thin rectilinear endometrium.

Tamoxifen-induced uterine abnormalities: the role of imaging

Tamoxifen citrate is an orally administered, nonsteroidal antiestrogen agent that is widely used for the treatment of breast cancer and that has recently been found to prevent breast cancer in some high-risk populations. Tamoxifen may, however, cause adverse effects at the uterine level. In this article, the authors review (a) the histopathologic uterine changes associated with tamoxifen therapy, (b) the spectrum of uterine imaging findings in women treated with tamoxifen, and (c) the recommendations of the American College of Obstetrics and Gynecology for women treated with tamoxifen. An algorithm for imaging evaluation of the uterus in women treated with tamoxifen is presented.

American Society of Clinical Oncology technology assessment on breast cancer risk reduction strategies: tamoxifen and raloxifene

OBJECTIVE

To conduct an evidence-based technology assessment to determine whether tamoxifen and raloxifene as breast cancer risk-reduction strategies are appropriate for broad-based conventional use in clinical practice.

POTENTIAL INTERVENTION

Tamoxifen and raloxifene.

OUTCOME

Outcomes of interest include breast cancer incidence, breast cancer-specific survival, overall survival, and net health benefits.

EVIDENCE

A comprehensive, formal literature review was conducted for tamoxifen and raloxifene on the following topics: breast cancer risk reduction; tamoxifen side effects and toxicity, including endometrial cancer risk; tamoxifen influences on nonmalignant diseases, including coronary heart disease and osteoporosis; and decision making by women at risk for breast cancer. Testimony was collected from invited experts and interested parties.

VALUES

More weight was given to publications that described randomized trials. BENEFITS/HARMS/COSTS: The American Society of Clinical Oncology (ASCO) Working Group acknowledges that a woman's decision regarding breast cancer risk-reduction strategies will depend on the importance and weight attributed to the information provided regarding both cancer and non-cancer-related risks.

CONCLUSIONS

For women with a defined 5-year projected risk of breast cancer of >/= 1.66%, tamoxifen (at 20 mg/d for up to 5 years) may be offered to reduce their risk. It is premature to recommend raloxifene use to lower the risk of developing breast cancer outside of a clinical trial setting. On the basis of available information, use of raloxifene should currently be reserved for its approved indication to prevent bone loss in postmenopausal women. Conclusions are based on single-agent use of the drugs. At the present time, the effect of using tamoxifen or raloxifene with other medications (such as hormone replacement therapy), or using tamoxifen and raloxifene in combination or sequentially, has not been studied adequately. The continuing use of placebo-controlled trials in other risk-reduction trials highlights the current unanswered issues concerning the use of such interventions, especially when the influence on net health benefit remains to be determined. Breast cancer risk reduction is a rapidly evolving area. This technology assessment represents an ongoing process with existing plans to monitor and review data and to update recommendations in a timely matter. (See

VALIDATION

The conclusions of the Working Group were evaluated by the ASCO Health Services Research Committee and by the ASCO Board of Directors.

SPONSOR

American Society of Clinical Oncology.

Uterine surveillance of asymptomatic postmenopausal women taking tamoxifen

The aim of this study was to assess the ability of transvaginal sonography (TVS) and office hysteroscopy with sharp curettage to characterize the morphological changes in the uteri of asymptomatic postmenopausal women taking long-term tamoxifen for breast cancer. The overall acceptability of a single-visit screening clinic for these women was also evaluated. Fifty-eight women were recruited from patients undergoing regular follow-up at the Leicester Royal Infirmary for breast cancer. A single-visit clinic was acceptable to 94.8% of these women. Transvaginal sonography detected endometrial thickness of greater than 5 mm in 84.5% of cases, but there was no relationship between total tamoxifen exposure and endometrial thickness. Transvaginal sonography also detected uterine lesions such as fibroids and endometrial cysts in 34.5% of cases. Hysteroscopy detected the latter uterine lesions in 53.4% of cases, with three cases (5.2%) of endometrial polyps also being identified in these women. Sharp curettage sampling of the endometrium produced specimens sufficient for diagnosis in 84.5% of cases; 70.7% of specimens were reported as showing types of 'quiescent' endometrium with 13.8% of specimens showing 'active' endometrium. In the latter group, there was a case of complex hyperplasia detected and also a case with granulomatous endometritis. For each histopathological diagnosis identified, there was a wide range of endometrial thickness recorded by TVS. A single-visit screening clinic involving TVS and hysteroscopy with sharp curettage was acceptable to asymptomatic women taking tamoxifen. However, hysteroscopy was more effective than TVS in detecting endometrial lesions such as polyps, fibroids and cystic areas. Although TVS detected endometrial thickness greater than 5 mm in the majority of cases, there were no malignancies detected and, for each histopathological classification, there was a wide range of endometrial thickness associated. Thus, the isolated use of TVS is insufficient for screening the endometria of these women.