Safety of aromatase inhibitors in the adjuvant setting

Aromatase inhibitors for the treatment of breast cancer: An overview (2019-2023)

Aromatase inhibition is considered a legitimate approach for the treatment of ER-positive (ER+) breast cancer as it accounts for more than 70% of breast cancer cases. Aromatase inhibitor therapy has been demonstrated to be highly effective in decreasing tumour size, increasing survival rates, and lowering the chance of cancer recurrence. The present review deliberates the pathophysiology and the role of aromatase in estrogen biosynthesis. Estrogen biosynthesis, various androgens, and their function in the human body have also been discussed. The salient aspects of the aromatase active site, its mode of action, and AIs, along with their intended interactions with presently FDA-approved inhibitors, have been briefly discussed. It has been detailed how different reported AIs were designed, their SAR investigations, in silico analysis, and biological evaluations. Various AIs from multiple origins, such as synthetic and semi-synthetic, have also been discussed.

Comparing the effect of aromatase inhibitor (letrozole) + cabergoline (Dostinex) and letrozole alone on uterine myoma regression,a randomized clinical trial

OBJECTIVE

To evaluate the effect of letrozole in combination with cabergoline and letrozole alone on regression of symptomatic uterine myomas in women of reproductive age.

DESIGN

Randomized controlled clinical trial.

SETTING

University hospital.

PATIENTS

Ninety-one women of reproductive age were enrolled in the study and 88 women were eligible. Eight participants were excluded from the study.

INTERVENTIONS

Eighty women of reproductive age with symptomatic myomas >4cm were evaluated in two groups. Participants in Group 1 received 2.5mg letrozole once daily and cabergoline 0.5mg/week from the first day of the menstrual cycle for 12 weeks, and participants in Group 2 received letrozole alone.

MAIN OUTCOME MEASURES

Changes in uterine size and volume; myoma size, volume and number; and side effects of treatment.

RESULTS

Overall, 76 patients completed the study. Compared with baseline values, mean uterine volume was reduced significantly in both groups (p=0.01), and there was no significant difference between groups (p=0.99). The mean number of dominant myomas was reduced significantly in both groups (p=0.03), with no significant difference between groups (p=0.6). The mean volume of myomas was reduced significantly in both groups (p=0.01), with no significant difference between groups (p=0.45). Although a significant decrease in number and volume of myomas was documented in each group (p<0.05), the intergroup analyses did not reveal significant differences between the two groups in terms of the change in number (p=0.28) and volume (p=0.96) of myomas. Headache was significantly more common in the letrozole+cabergoline group (nine vs two cases, p=0.02), but the two groups were comparable for the remaining minor side effects.

CONCLUSION

This study showed that 12 weeks of treatment with letrozole with and without cabergoline improved the size and volume of the uterus and myomas, led to symptom improvement, and could be used for short-term treatment prior to surgery or fertility programmes.

CONDENSATION

Condensation letrozole in combination with cabergoline in the management of uterine fibroids.

CE: A Review of Common Oral Treatments for Breast Cancer: Improving Patient Safety in Nononcology Settings

: Breast cancer patients are living longer with the disease than ever before. According to the National Cancer Institute, more than 3 million women in the United States are currently living with a breast cancer diagnosis, and many seek care in nononcology settings, whether for treatment, acute symptoms and complaints related to their cancer diagnosis, or unrelated concerns. Yet many nononcology providers are unfamiliar with the various oral agents used to treat breast cancer, and their possible adverse effects and drug interactions. It is imperative that all providers be aware of these agents and know when a patient is currently taking or has taken them. This article provides an overview of the most common oral treatments for breast cancer and discusses common adverse effects and management.

Targeting mixed lineage kinases in ER-positive breast cancer cells leads to G2/M cell cycle arrest and apoptosis

Estrogen receptor (ER)-positive tumors represent the most common type of breast cancer, and ER-targeted therapies such as antiestrogens and aromatase inhibitors have therefore been widely used in breast cancer treatment. While many patients have benefited from these therapies, both innate and acquired resistance continue to be causes of treatment failure. Novel targeted therapeutics that could be used alone or in combination with endocrine agents to treat resistant tumors or to prevent their development are therefore needed. In this report, we examined the effects of inhibiting mixed-lineage kinase (MLK) activity on ER-positive breast cancer cells and non-tumorigenic mammary epithelial cells. Inhibition of MLK activity with the pan-MLK inhibitor CEP-1347 blocked cell cycle progression in G2 and early M phase, and induced apoptosis in three ER-positive breast cancer cell lines, including one with acquired antiestrogen resistance. In contrast, it had no effect on the cell cycle or apoptosis in two non-tumorigenic mammary epithelial cell lines. CEP-1347 treatment did not decrease the level of active ERK or p38 in any of the cell lines tested. However, it resulted in decreased JNK and NF-κB activity in the breast cancer cell lines. A JNK inhibitor mimicked the effects of CEP-1347 in breast cancer cells, and overexpression of c-Jun rescued CEP-1347-induced Bax expression. These results indicate that proliferation and survival of ER-positive breast cancer cells are highly dependent on MLK activity, and suggest that MLK inhibitors may have therapeutic efficacy for ER-positive breast tumors, including ones that are resistant to current endocrine therapies.

Employment outcomes among survivors of common cancers: the Symptom Outcomes and Practice Patterns (SOAPP) study

INTRODUCTION

Risk factors for employment difficulties after cancer diagnosis are incompletely understood, and interventions to improve post-cancer employment remain few. New targets for intervention are needed.

METHODS

We assessed a cohort of 530 nonmetastatic cancer patients (aged ≤ 65 years, >6 months from diagnosis, off chemo- or radiotherapy) from the observational multi-site Symptom Outcomes and Practice Patterns study. Participants reported employment change, current employment, and symptoms. Groups were based on employment at survey (working full- or part-time versus not working) and whether there had been a change due to illness (yes versus no). The predictive power of symptom interference with work was evaluated for employment group (working stably versus no longer working). Race/ethnicity, gender, cancer type, therapy, and time since diagnosis were also assessed. Association between employment group and specific symptoms was examined.

RESULTS

The cohort was largely non-Hispanic white (76 %), female (85 %), and diagnosed with breast cancer (75 %); 24 % reported a change in employment. On multivariable analysis, participants with at least moderate symptom interference were more likely to report no longer working than their less effected counterparts (odds ratio (OR) = 8.0, 95 % CI, 4.2-15.4), as were minority participants compared with their non-Hispanic white counterparts (OR = 3.2, 95 % CI, 1.8-5.6). Results from the multiple regression model indicated the combination of fatigue (OR = 2.3, 95 % CI, 1.1-4.7), distress (OR = 3.9, 95 % CI, 1.7-9.0), and dry mouth (OR = 2.6, 95 % CI, 1.1-6.2) together with race/ethnicity and time since diagnosis adequately accounted for employment group.

CONCLUSIONS

Our findings support the hypothesis that residual symptom burden is related to post-cancer employment: Residual symptoms may be targets for intervention to improve work outcomes among cancer survivors.

IMPLICATIONS FOR CANCER SURVIVORS

This analysis examines whether increased symptom burden is associated with a change to not working following a cancer diagnosis. We also examined individual symptoms to assess which symptoms were most strongly associated with not working after a cancer diagnosis. Our hope is that we will be able to use this information to both screen survivors post-active treatment as well as target high-risk symptoms for further and more aggressive intervention, in an attempt to improve post-cancer work outcomes.

Dry eye syndrome in aromatase inhibitor users

BACKGROUND

Aromatase inhibitors are frequently used as an adjuvant therapy in the treatment of breast cancer. We observed that several patients taking aromatase inhibitors presented with severe dry eye symptoms, and we investigated whether there is a relationship between aromatase inhibitors and dry eyes in these patients.

DESIGN

Retrospective chart review.

PARTICIPANTS

Forty-one women.

METHODS

A computerized search of health records was performed to identify patients using anastrazole, letrozole and exemestane seen by the Cornea Service from August 2008 to March 2011. The results were compared with age-matched controls.

MAIN OUTCOME MEASURES

Ocular surface changes among aromatase inhibitors users.

RESULTS

Of the 41 women, 39 were Caucasians. Thirty-nine patients had breast cancer (95%), one patient had ovarian cancer (2.5%) and one had an unknown primary cancer. Mean age was 68 ± 11.3 years (range 47-95). Most common presenting symptoms were blurred vision in 28 (68%) patients, irritation/foreign body sensation in 12 (29%) patients, redness in 9 (22%) patients, tearing in 6 (22%) patients and photosensitivity in 2 (5%) patients. Mean Schirmer's test measurement was 11 ± 5.8 mm (range 0.5-20 mm). Blepharitis was noted in 68 of 82 eyes (73%), decreased or poor tear function in 24 eyes (29%), conjunctival injection in 18 eyes (22%) and superficial punctate keratitis in 12 eyes (29%). Among an age-matched population (45-95 years), dry eye syndrome was found in only 9.5% of patients.

CONCLUSIONS

Because the prevalence of ocular surface disease signs and symptoms appears to be higher in study group than control patients, aromatase inhibitors might be a contributing factor to the dry eye symptoms.

The importance of nonpharmacogenetic factors in endocrine therapy

Nonpharmacogenetic factors may play a key role in the success of oral endocrine therapy for breast cancer. Adherence, defined as following medical advice as well as persistence and duration of use for patients prescribed endocrine therapy, may impact significantly on recurrence and survival. Side effects from tamoxifen or aromatase inhibitors may lead to patients stopping or switching therapy, while comorbidities, consequent coprescribing and patient perceptions may also influence outcomes. Interventions to improve adherence and persistence are required and could have as great an effect on survival as applying pharmacogenetic principles to the endocrine management of breast cancer.

High prevalence of low vitamin D and musculoskeletal complaints in women with breast cancer

Reduced vitamin D levels may play a significant role in the development of fractures and musculoskeletal pains reported in patients on aromatase inhibitors (AIs) for breast cancer. In this study, we evaluated the vitamin D status in postmenopausal women with non-metastatic breast cancer who were about to start AI therapy. This study was conducted on community dwelling postmenopausal subjects, aged 35-80 years, with early non-metastatic breast cancer (up to stage IIIA), who were about to start therapy using third generation AIs. Symptoms of joint and muscle pains were obtained using a modified Leuven menopausal questionnaire. 25-hydroxyvitamin D [25(OH)D] was evaluated by radioimmunoassay while bone mineral density (BMD) of the lumbar spine and the proximal femur by dual energy x-ray absorptiometry (DXA). Of the 145 participants (mean age = 60.96 ± 0.88 years), 63 of 145 (43.5%) had baseline levels of 25(OH)D of < 20 ng/mL (deficient), 50 of 145 (34.5%) had levels between 20 and 29 ng/mL (insufficient), and only 32 of 145 (22%) had ≥ 30 ng/mL (sufficient); thus, 113 of 145 (78%) had low 25(OH)D levels (i.e., < 30 ng/mL). Arthralgias and myalgias were found in 61.3% and 43% of patients, respectively; and of those, 83.3% and 88.1% had 25(OH)D of < 30 ng/mL, respectively. Prevalence of vitamin D deficiency is high in breast cancer women and this may increase the risk of bone loss and fractures in those who are going to start AIs. Moreover, musculoskeletal pains are common in breast cancer women, even before the initiation of AIs and in association with low vitamin D in the majority. Future studies may be needed to establish the contribution of low vitamin D, if any, on the prevalence of musculoskeletal pains in women on AIs.

Urogenital disorders in women with adjuvant endocrine therapy after early breast cancer

OBJECTIVE

To investigate the prevalence of urogenital symptoms and vaginal atrophy in postmenopausal breast cancer patients on adjuvant endocrine therapy.

STUDY DESIGN

A population-based, cross-sectional study on postmenopausal breast cancer patients on adjuvant endocrine treatment and age-matched control subjects. Vaginal atrophy was assessed by gynecologic examination and atrophy-related symptoms by validated questionnaires.

RESULTS

In all, 57.6% of aromatase inhibitor-treated and 32.4% of tamoxifen-treated breast cancer patients rated at least 1 vaginal atrophy symptom as moderate/severe, which was significantly more common than in control subjects (P < .01). Aromatase inhibitor-treated patients more often had moderate or severe vaginal atrophy (P < .05), a more atrophic cytohormonal evaluation, and significantly higher vaginal pH (P < .05) than all control subjects, irrespective of hormonal use.

CONCLUSION

Our findings indicate that the frequency of vaginal atrophy symptoms, particularly in aromatase inhibitor-treated women, might have been underestimated in previous clinical trials.

Adverse events and bone health during anastrozole therapy in postmenopausal Japanese breast cancer patients

BACKGROUND

Although anastrozole (ANA), an aromatase inhibitor (AI), has been widely used for breast cancer patients; adverse events during ANA therapy in Japanese patients have not been reported.

METHODS

The study included 656 postmenopausal breast cancer patients receiving ANA as postoperative adjuvant therapy in our hospital. Adverse events during ANA therapy, such as musculoskeletal effects and cerebro- and cardiovascular accidents, were investigated over a 5-year period. The percentage changes in lumbar (L2-4) spine bone mineral density (BMD) were determined in 71 patients receiving ANA alone and 26 patients receiving bisphosphonate in combination with ANA for 7-24 months.

RESULTS

The follow-up period ranged from 6 to 60 months (median 23 months). Joint pain, the most common adverse event, was observed in 3.6% (24/656) of the patients. Cerebral infarctions occurred in 0.3% (2/656) of the patients, and no cardiovascular accidents occurred. Bone fractures occurred in nine patients receiving ANA alone. The mean age and BMD of the nine patients were 67.6 years and 71.8% (compared to the young adult mean BMD), respectively. Accumulated and annual fracture rates were 1.3 and 0.8%, respectively. A decrease in BMD was observed in 62.0% (44/71) of the ANA group compared to 26.9% (7/26) of the combination bisphosphonate group (P < 0.01).

CONCLUSION

Incidence of adverse events during AI therapy in this Japanese postmenopausal population appears to be lower than that of the ATAC trial. The incidence of bone fractures during AI therapy is lower in Japan, and the addition of bisphosphonates enhances bone health. We should perform a prospective trial in the future to investigate the precise risk of bone fractures in Japanese patients.

NCCN Task Force Report: Bone Health in Cancer Care

Bone health and maintenance of bone integrity are important components of comprehensive cancer care in both early and late stages of disease. Risk factors for osteoporosis are increased in patients with cancer, including women with chemotherapy-induced ovarian failure, those treated with aromatase inhibitors for breast cancer, men receiving androgen-deprivation therapy for prostate cancer, and patients undergoing glucocorticoid therapy. The skeleton is a common site of metastatic cancer recurrence, and skeletal-related events are the cause of significant morbidity. The National Comprehensive Cancer Network (NCCN) convened a multidisciplinary task force on Bone Health in Cancer Care to discuss the progress made in identifying effective screening and therapeutic options for management of treatment-related bone loss; understanding the factors that result in bone metastases; managing skeletal metastases; and evolving strategies to reduce bone recurrences. This report summarizes presentations made at the meeting.

Selective inhibition of 17beta-hydroxysteroid dehydrogenase type 1 (17betaHSD1) reduces estrogen responsive cell growth of T47-D breast cancer cells

The most potent estrogen estradiol (E2) plays a pivotal role in the initiation and progression of estrogen dependent diseases. 17beta-Hydroxysteroid dehydrogenase type 1 (17betaHSD1) catalyses the NADPH-dependent E2-formation from estrone (E1). It is often overexpressed in breast cancer and endometriosis. For this reason, inhibition of 17betaHSD1 is a promising strategy for the treatment of these diseases. In the present paper, we investigate the estrogen responsive cell growth of T47-D breast cancer cells, the intracellular inhibitory activity of non-steroidal 17betaHSD1-inhibitors and their effects on estrogen dependent cell growth in vitro. At equal concentrations the estrogens E1 and E2 induced the same extent of growth stimulation indicating fast intracellular conversion of E1 into E2. Application of inhibitors selectively prevented stimulation of proliferation evoked by E1-treatment whereas E2-mediated stimulation was not affected. Furthermore, intracellular E2-formation from E1 was significantly inhibited with IC(50)-values in the nanomolar range. In conclusion, our findings strongly support suitability of non-steroidal 17betaHSD1-inhibitors for the treatment of estrogen dependent diseases.

Current awareness: pharmacoepidemiology and drug safety

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of pharmacoepidemiology and drug safety. Each bibliography is divided into 20 sections: 1 Reviews; 2 General; 3 Anti‐infective Agents; 4 Cardiovascular System Agents; 5 CNS Depressive Agents; 6 Non‐steroidal Anti‐inflammatory Agents; 7 CNS Agents; 8 Anti‐neoplastic Agents; 9 Haematological Agents; 10 Neuroregulator‐Blocking Agents; 11 Dermatological Agents; 12 Immunosuppressive Agents; 13 Autonomic Agents; 14 Respiratory System Agents; 15 Neuromuscular Agents; 16 Reproductive System Agents; 17 Gastrointestinal System Agents; 18 Anti‐inflammatory Agents ‐ Steroidal; 19 Teratogens/fetal exposure; 20 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.

Current awareness: Pharmacoepidemiology and drug safety

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of pharmacoepidemiology and drug safety. Each bibliography is divided into 20 sections: 1 Reviews; 2 General; 3 Anti‐infective Agents; 4 Cardiovascular System Agents; 5 CNS Depressive Agents; 6 Non‐steroidal Anti‐inflammatory Agents; 7 CNS Agents; 8 Anti‐neoplastic Agents; 9 Haematological Agents; 10 Neuroregulator‐Blocking Agents; 11 Dermatological Agents; 12 Immunosuppressive Agents; 13 Autonomic Agents; 14 Respiratory System Agents; 15 Neuromuscular Agents; 16 Reproductive System Agents; 17 Gastrointestinal System Agents; 18 Anti‐inflammatory Agents ‐ Steroidal; 19 Teratogens/fetal exposure; 20 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.

Meta-analysis of pre-operative aromatase inhibitor versus tamoxifen in postmenopausal woman with hormone receptor-positive breast cancer

PURPOSE

Clinical trials have reported conflicting results as to whether pre-operative aromatase inhibitors (AIs) improve outcome over pre-operative tamoxifen in postmenopausal women with hormone receptor-positive breast cancer.

METHODS

We performed a meta-analysis comparing primary and secondary end points of pre-operative AI and pre-operative tamoxifen. The event-based risk ratio (RR) with 95% confidence intervals (95% Cis) were derived, and a test of heterogeneity was applied.

RESULTS

Four studies (1,160 patients) met the inclusion criteria for the analysis. Meta-analysis showed that pre-operative AI was more effective than pre-operative tamoxifen. Pooled results of clinical efficacy were as follows: clinical objective response rate (RR, 1.29; 95% CI, 1.14-1.47; P < 0.001), ultrasound objective response rate (RR, 1.29; 95% CI, 1.10-1.51; P = 0.002), and breast conserving surgery (BCS) rate (RR, 1.36; 95% CI, 1.16-1.59; P < 0.001). Hot flashes, nausea, and fatigue were not different between the pre-operative AI and pre-operative tamoxifen groups. Although headache was more frequent in the pre-operative AI group (P = 0.011), it was a manageable toxicity and was not clinically relevant.

CONCLUSION

Pre-operative AI has better BCS rate than tamoxifen and in terms of toxicities, is not inferior to tamoxifen; therefore, we could suggest pre-operative AI instead of tamoxifen for those postmenopausal patients with hormone receptor positive breast cancer, not eligible for chemotherapy.