Adjuvant endocrine therapy for premenopausal women with early breast cancer

Neuropsychological assessment, intervention, and best practices for women with non-Central nervous system cancer: A scoping review of current standards

Objective: Existing literature has sought to characterize the broad cognitive impact of non-central nervous system cancer and its treatment, including chemotherapy, radiation, surgery, and hormonal regulation. However, despite the frequency of women that are diagnosed with breast and gynecological cancer, there is limited research on the specific cognitive experiences of women undergoing cancer treatment. Presently, the current literature lacks concise guidance for neuropsychologists to support the cognitive health of women facing cancer, despite the acknowledged impact of cancer interventions and chronic illness on cognitive outcomes. Method: Applying scoping review criteria outlined by Peters et al. (2015) and adhering to Preferred Reporting Items for Systemic Reviews and Meta-Analysis (PRISMA) guidelines, we conducted a comprehensive examination of literature spanning multiple databases (Google Scholar, PubMed, PsychINFO) with a focus on the cognitive impact of cancer treatment on women. Conclusions: Women are subject to unique treatment-related outcomes due to the impact of hormonal alterations, differences in metabolization of certain chemotherapies, and psychosocial risk factors. Despite the known impact of cancer intervention, chronic illness, and cancer-related sequelae on cognitive outcomes, the current literature does not parsimoniously outline best practices for neuropsychologists to promote the health of women experiencing cancer. The current paper (1) provides an overview of the cognitive implications of cancer treatment with an intentional focus on cancers that are more prevalent in women versus men, (2) addresses the characteristics of this impact for women undergoing cancer intervention(s), and (3) provides possible intervention and treatment strategies for mental health providers and neuropsychologists.

Phytoestrogens, novel dietary supplements for breast cancer

While endocrine therapy is considered as an effective way to treat breast cancer, it still faces many challenges, such as drug resistance and individual discrepancy. Therefore, novel preventive and therapeutic modalities are still in great demand to decrease the incidence and mortality rate of breast cancer. Numerous studies suggested that G protein-coupled estrogen receptor (GPER), a membrane estrogen receptor, is a potential target for breast cancer prevention and treatment. It was also shown that not only endogenous estrogens can activate GPERs, but many phytoestrogens can also function as selective estrogen receptor modulators (SERMs) to interact GPERs. In this review, we discussed the possible mechanisms of GPERs pathways and shed a light of developing novel phytoestrogens based dietary supplements against breast cancers.

Ovarian hyperstimulation in premenopausal women during adjuvant tamoxifen treatment for endocrine-dependent breast cancer: A report of two cases

Adjuvant endocrine therapy is an integral component of care for endocrine-dependent breast cancer. The aim of this type of therapy is to counteract the production and the action of estrogens. The ovary is the primary site of estrogen production in premenopausal women, whereas, in postmenopausal women, the main source of estrogens is adipose tissue. Therefore, ovarian function suppression is an effective adjuvant strategy in premenopausal estrogen-dependent breast cancer. Similarly, the inhibition of estrogen action at the receptor site by tamoxifen has proven to be effective. To date, international consensus statements recommend tamoxifen (20 mg/day) for five years as the standard adjuvant endocrine therapy for premenopausal women. It should be noted that tamoxifen is a potent inducer of ovarian function and consequent hyperestrogenism in premenopausal women. In the present study, we report two cases of ovarian cyst formation with very high estrogen levels and endometrial hyperplasia during the administration of tamoxifen alone as adjuvant treatment for estrogen receptor-positive breast cancer in premenopausal women. These cases suggest that in young premenopausal patients with estrogen-dependent breast cancer, ovarian suppression is an essential prerequisite for an adjuvant endocrine therapy with tamoxifen. In this context, luteinizing hormone-releasing hormone agonist treatment by suppressing effective ovarian function may lead to a hypoestrogenic status that may positively impact breast cancer prognosis and prevent the effects of tamoxifen at the gynecological level. It is important to reconsider the action of tamoxifen on ovarian function and include these specific effects of tamoxifen in the informed consent of premenopausal patients who are candidates for tamoxifen alone as adjuvant endocrine treatment.

Smaller reduction in 3D breast density associated with subsequent cancer recurrence in patients with breast cancer receiving adjuvant tamoxifen therapy

OBJECTIVE

The purpose of this study was to retrospectively investigate whether 3D breast density changes measured using MRI were associated with recurrent cancer in patients with breast cancer who received adjuvant tamoxifen.

MATERIALS AND METHODS

A search of the breast MRI database (2007-2008) revealed a dataset that included 80 women (mean age, 44 years; range, 27-68 years) with breast cancer who underwent breast-conserving surgery, adjuvant tamoxifen treatment, and breast MRI before and after tamoxifen. The following clinicopathologic variables were collected: age, body mass index, menopausal status, family history, tumor stage, tumor grade, hormonal receptor status, and adjuvant chemotherapy status. MRI variables (total breast volume, fibro-glandular volume, and breast density) were measured for the contralateral untreated breast before and after tamoxifen treatment, and the percentage changes were recorded. A multivariate logistic regression analysis was performed to identify independent factors that were associated with cancer recurrence.

RESULTS

Overall, 12 (15%) of the 80 women developed recurrence. No recurrent cancers were found in the remaining 68 patients (85%) at a median follow-up of 48 months (range, 37-60 months). Percentage reduction of breast density after tamoxifen was the only independent factor associated with recurrence (adjusted odds ratio [OR] = 0.848, 95% CI = 0.769-0.935, and p = 0.001 for observer 1; adjusted OR = 0.957, 95% CI = 0.919-0.996, and p = 0.032 for observer 2) in the multivariate analysis.

CONCLUSION

Three-dimensional breast density changes measured using MRI during tamoxifen treatment were an independent factor associated with cancer recurrence in patients with breast cancer who received adjuvant tamoxifen.

Efficacy and tolerability of toremifene and tamoxifen therapy in premenopausal patients with operable breast cancer: a retrospective analysis

BACKGROUND

Given the use of tamoxifen as standard treatment for hormone receptor-positive breast cancer, the use of toremifene as an adjuvant endocrine therapy has not been widely examined. The present retrospective study compared the efficacy and safety of toremifene and tamoxifen in the treatment of operable hormone receptor-positive breast cancer in premenopausal women.

METHODS

Premenopausal patients with hormone receptor- positive operable breast cancer were eligible. Enrolled patients (n = 1847) received either 60 mg toremifene (n = 396) or 20 mg tamoxifen (n = 1451) daily for a minimum of 5 years after surgery. Disease-free survival (dfs) was the primary endpoint. Overall survival (os) and time to distant recurrence were secondary endpoints.

RESULTS

Treatment with toremifene and tamoxifen resulted in no between-group differences in dfs (p = 0.659) or os (p = 0.364). Mean dfs was 10.3 years for both groups. Mean os was 11.2 years for the toremifene group and 11.1 years for tamoxifen group. The 5-year dfs rate was 87.0% in the toremifene group and 85.0% in the tamoxifen group. The 5-year survival rate was 94.3% in the toremifene group and 93.5% in the tamoxifen group. Adverse events rates were similar in the two groups, with the exception of irregular menses, which occurred at a higher rate in the tamoxifen group than in the toremifene group (10.0% vs. 6.3%, p = 0.025).

CONCLUSIONS

In this retrospective study, the efficacy and safety profiles of toremifene and tamoxifen for the treatment of operable hormone receptor-positive breast cancer in premenopausal women were similar.

Effects of toremifene versus tamoxifen on breast cancer patients: a meta-analysis

Toremifene and tamoxifen are both selective estrogen receptor modulators used in the treatment of breast cancer patients. Therefore, we carried out a meta-analysis to achieve a more precise evaluation of the effects of toremifene versus tamoxifen on breast cancer patients, including the efficacy and safety, and the effects on the uterus, lipids, and bone. Comprehensive literature searches were conducted using the electronic databases and reference lists to include randomized controlled trials (RCTs) that compared toremifene with tamoxifen for breast cancer patients. Two reviewers independently selected studies and abstracted data. Data were analyzed by Review Manager, version 5.0. Twenty-three trials (7242 patients) were included. For early stage breast cancer, toremifene was associated with higher 5-year survival rates (OR 1.25, 95 % CI 1.04, 1.50), more vaginal discharge (OR 1. 32, 95 % CI 1.01, 1.73), a greater decrease in serum triglyceride levels (SMD -1.01, 95 % CI -1.89, -0.14), a smaller decrease in LDL cholesterol levels (SMD 0.45, 95 % CI 0.07, 0.84) and in bone mineral density in Ward's triangle (SMD -0.36, 95 % CI -0.71, -0.01), and a greater increase in HDL cholesterol levels (SMD 0.43, 95 % CI 0.08, 0.77) than tamoxifen. For advanced breast cancer patients, toremifene was associated with more vaginal bleeding (OR 0.45, 95 % CI 0.26, 0.80) and a greater decrease in serum triglyceride levels (SMD -1.15, 95 % CI -1.90, -0.39) than tamoxifen. Available evidence showed that toremifene could be an alternative option to tamoxifen for both early and advanced breast cancer patients. However, the methodological quality of the included studies was low. More rigorous RCTs are needed to confirm the results of this meta-analysis in the future.

A comparison of survival outcomes and side effects of toremifene or tamoxifen therapy in premenopausal estrogen and progesterone receptor positive breast cancer patients: a retrospective cohort study

BACKGROUND

In premenopausal women, endocrine adjuvant therapy for breast cancer primarily consists of tamoxifen alone or with ovarian suppressive strategies. Toremifene is a chlorinated derivative of tamoxifen, but with a superior risk-benefit profile. In this retrospective study, we sought to establish the role of toremifene as an endocrine therapy for premenopausal patients with estrogen and/or progesterone receptor positive breast cancer besides tamoxifen.

METHODS

Patients with early invasive breast cancer were selected from the breast tumor registries at the Sun Yat-Sen Memorial Hospital (China). Premenopausal patients with endocrine responsive breast cancer who underwent standard therapy and adjuvant therapy with toremifene or tamoxifen were considered eligible. Patients with breast sarcoma, carcinosarcoma, concurrent contralateral primary breast cancer, or with distant metastases at diagnosis, or those who had not undergone surgery and endocrine therapy were ineligible. Overall survival and recurrence-free survival were the primary outcomes measured. Toxicity data was also collected and compared between the two groups.

RESULTS

Of the 810 patients reviewed, 452 patients were analyzed in the study: 240 received tamoxifen and 212 received toremifene. The median and mean follow up times were 50.8 and 57.3 months, respectively. Toremifene and tamoxifen yielded similar overall survival values, with 5-year overall survival rates of 100% and 98.4%, respectively (p = 0.087). However, recurrence-free survival was significantly better in the toremifene group than in the tamoxifen group (p = 0.022). Multivariate analysis showed that recurrence-free survival improved independently with toremifene (HR = 0.385, 95% CI = 0.154-0.961; p = 0.041). Toxicity was similar in the two treatment groups with no women experiencing severe complications, other than hot flashes, which was more frequent in the toremifene patients (p = 0.049). No patients developed endometrial cancer.

CONCLUSION

Toremifene may be a valid and safe alternative to tamoxifen in premenopausal women with endocrine-responsive breast cancer.

Low-dose dietary genistein negates the therapeutic effect of tamoxifen in athymic nude mice

The present study examined the effect of dietary genistein, a soy isoflavone, on breast cancer patients who take tamoxifen, an antiestrogen treatment, using a preclinical model. The interaction of various doses of genistein with tamoxifen on the growth of estrogen receptor-positive breast cancer MCF-7 cells was investigated by subcutaneously injecting MCF-7 cells into the flank of ovariectomized athymic mice. Animals were randomized into eight experimental groups with 10-13 mice per group: control (C), estrogen (E) (0.08 mg E implant), tamoxifen (T) (3 mg T implant), estrogen + tamoxifen (E + T), tamoxifen + 500 p.p.m. genistein (T + G500), estrogen + tamoxifen + 250 p.p.m. genistein (E + T + G250), estrogen + tamoxifen + 500 p.p.m. genistein (E + T + G500) and estrogen + tamoxifen + 1000 p.p.m. genistein (E + T + G1000). Treatment of tamoxifen significantly reduced the estrogen-induced MCF-7 tumor prevalence and tumor size. This inhibitory effect of tamoxifen was significantly negated by the low doses of dietary genistein (250 and 500 p.p.m.), whereas the 1000 p.p.m. genistein did not have the same effect. Cells harvested from tamoxifen-treated tumors retained estrogen responsiveness of their progenitor MCF-7 cells, indicating that the abrogating effect of genistein on tamoxifen-treated tumor growth was not caused by a diminished tamoxifen response but directly by genistein. The low doses of dietary genistein abrogated the inhibitory effect of tamoxifen potentially by acting on the tumor cell proliferation/apoptosis ratio and the messenger RNA (mRNA) expression of cyclin D1 in addition to regulating the mRNA expression of progesterone receptor. Therefore, data from the current study suggest that caution is warranted regarding the consumption of dietary genistein by breast cancer patients while on tamoxifen therapy.

Pharmacology and clinical applications of selective estrogen receptor modulators

Compounds that can be described as selective estrogen receptor modulators (SERMs) have expanded dramatically over the past two decades. The ability of SERMs to act as estrogens in certain tissues while remaining inert or acting as an anti-estrogen in other tissues has opened up opportunities for treating specific estrogen-modulated diseases without accepting the risk of systemic estrogen activity. SERM development has resulted in significant therapeutic advances for breast cancer, osteoporosis and potentially other diseases associated with the menopause. After the publication of the Women's Health Initiative, interest in compound selectivity that reduces menopausal symptoms while protecting bone, breast, uterus and the heart has increased. Future SERMs may also have a therapeutic profile that can be tailored to specific patient populations, including men. This review paper summarizes the characteristics of different SERMs from various pharmacological categories and the feasibility and scope of their use for a large range of disease/health conditions.

Breast cancer in young women and its impact on reproductive function

BACKGROUND

Breast cancer is the most common cancer in women in developed countries, and 12% of breast cancer occurs in women 20-34 years. Survival from breast cancer has significantly improved, and the potential late effects of treatment and the impact on quality of life have become increasingly important. Young women constitute a minority of breast cancer patients, but commonly have distinct concerns and issues compared with older women, including queries regarding fertility, contraception and pregnancy. Further, they are more likely than older women to have questions regarding potential side effects of therapy and risk of relapse or a new primary. In addition, many will have symptoms associated with treatment and they present a management challenge. Reproductive medicine specialists and gynaecologists commonly see these women either shortly after initial diagnosis or following adjuvant therapy and should be aware of current management of breast cancer, the options for women at increased genetic risk, the prognosis of patients with early stage breast cancer and how adjuvant systemic treatments may impact reproductive function.

METHODS

No systematic literature search was done. The review focuses on the current management of breast cancer in young women and the impact of treatment on reproductive function and subsequent management. With reference to key studies and meta-analyses, we highlight controversies and current unanswered questions regarding patient management.

RESULTS

Chemotherapy for breast cancer is likely to negatively impact on reproductive function. A number of interventions are available which may increase the likelihood of future successful pregnancy, but the relative safety of these interventions is not well established. For those who do conceive following breast cancer, there is no good evidence that pregnancy is detrimental to survival. We review current treatment; effects on reproductive function; preservation of fertility; contraception; pregnancy; breastfeeding and management of menopausal symptoms following breast cancer.

CONCLUSION

This paper provides an update on the management of breast cancer in young women and is targeted at reproductive medicine specialists and gynaecologists.