Extended duration of adjuvant aromatase inhibitor in breast cancer: a meta-analysis of randomized controlled trials

Appraising Adjuvant Endocrine Therapy in Hormone Receptor Positive HER2-Negative Breast Cancer—A Literature Review

Background: Approximately 75% of breast cancer (BC) is associated with luminal differentiation expressing endocrine receptors (ER). For ER+ HER2− tumors, adjuvant endocrine therapy (ET) is the cornerstone treatment. Although relapse events steadily continue, the ET benefits translate to dramatically lengthen life expectancy with bearable side-effects. This review of ER+ HER2− female BC outlines suitable adjuvant treatment strategies to help guide clinical decision making around appropriate therapy. Methods: A literature search was conducted in Embase, Medline, and the Cochrane Libraries, using ER+ HER−, ET BC keywords. Results: In low-risk patients: five years of ET is the standard option. While Tamoxifen remains the preferred selection for premenopausal women, AI is the choice for postmenopausal patients. In the high-risk category: ET plus/minus OFS with two years of Abemaciclib is recommended. Although extended ET for a total of ten years is an alternative, the optimal AI duration is undetermined; nevertheless an additional two to three years beyond the initial five years may be sufficient. In this postmenopausal group, bisphosphonate is endorsed. Conclusions: Classifying the risk category assists in deciding the treatment route and its optimal duration. Tailoring the breadth of ET hinges on a wide array of factors to be appraised for each individualized case, including weighing its benefits and harms.

Systemic Treatment of Breast Cancer. 1st Central-Eastern European Professional Consensus Statement on Breast Cancer

This text is based on the recommendations accepted by the 4th Hungarian Consensus Conference on Breast Cancer, modified based on the international consultation and conference within the frames of the Central-Eastern European Academy of Oncology. The professional guideline primarily reflects the resolutions and recommendations of the current ESMO, NCCN and ABC5, as well as that of the St. Gallen Consensus Conference statements. The recommendations cover classical prognostic factors and certain multigene tests, which play an important role in therapeutic decision-making. From a didactic point of view, the text first addresses early and then locally advanced breast cancer, followed by locoregionally recurrent and metastatic breast cancer. Within these, we discuss each group according to the available therapeutic options. At the end of the recommendations, we summarize the criteria for treatment in certain rare clinical situations.

Appraising the quality of meta-analysis for breast cancer treatment in the adjuvant setting: A systematic review

INTRODUCTION

Breast cancer is the tumor with highest incidence in women worldwide and adjuvant treatment is extremely important to achieve disease control. Given the relevance of systematic reviews, their rigor should be warranted to avoid biased conclusions. Our objective was to investigate the methodological quality of meta-analysis of early breast cancer adjuvant treatment.

MATERIAL AND METHODS

Comprehensive searches were performed using electronic databases from 1/1/2007 to 11/12/2018. All studies identified as a systematic review with meta-analysis investigating the efficacy of breast cancer adjuvant treatments were included. Two reviewers independently assessed titles and abstracts, then full-texts for eligibility. Quality was assessed using the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) version 2 tool.

RESULTS

Of 950 citations retrieved, 66 studies (7.0%) were deemed eligible. Methodological quality was highly variable, median AMSTAR score 8.5 (IQR 7-9.5) and range 0-16. There was a weak positive correlation between journal impact factor and AMSTAR score (r = 0.17) and citation rate and AMSTAR score (r = 0.16). Cochrane Systematic Reviews were of higher quality than reviews from other journals. Overall confidence was critically low for 61 (92.4%) studies, and the least well-reported domains were the statement of conflict of interest and funding source for the included studies (4.6%), the report of a pre-defined study protocol (15.2%), and the description of details of excluded studies (6.1%).

CONCLUSIONS

Our findings reinforce concerns about the design, conduction and interpretation of meta-analysis in current literature. Methodological quality should be carefully considered and journal editors, decision makers and readers in general, must follow a critical approach to this studies.

From Theory to Practice: Bone Health in Women with Early Breast Cancer Treated with Aromatase Inhibitors

Aromatase inhibitors (AI) are extensively used as adjuvant endocrine therapy in post-menopausal women with hormone receptor-positive early breast cancer (HR+ EBC), but their impact on bone health is not negligible. This work aimed to assess bone loss, fracture incidence, and risk factors associated with these events, as well as the prognostic influence of fractures. We have conducted a retrospective cohort study of women with HR+ EBC under adjuvant therapy with AI, during a 3-year period. Four-hundred-and-fifty-one eligible women were reviewed (median age 68 years). Median time under AI was 40 months. A fracture event occurred in 8.4%, mostly in the radium and femoral neck and in older women (mean 74 vs. 68 years, p = 0.006). Age (OR 1.01, 95% CI 1.01–1.07, p = 0.024) and time under AI (OR 1.02, 95% CI 1.00–1.04, p = 0.037) were independent predictors of fracture, with a fair discrimination (AUC 0.71). Analysis of disease-free survival according to fracture event varied between groups, disfavoring the fracture cohort (at 73 months, survival 78.6%, 95% CI, 47.6–92.4 vs. 95.6%, 95% CI, 91.2–97.8, p = 0.027). The multivariate model confirmed the prognostic impact of fracture occurrence (adjusted HR of 3.17, 95% CI 1.10–9.11; p = 0.032). Bone health is often forgotten, despite its great impact in survivorship. Our results validate the pathophysiologic link between EBC and bone metabolism, which translates into EBC recurrence. Further research in this area may help refine these findings. Moreover, early identification of women at higher risk for fractures is warranted.

Optimal duration of endocrine therapy with extended aromatase inhibitors for postmenopausal patients with hormone receptor-positive breast cancer: a meta-analysis

BACKGROUND

The optimal duration of endocrine therapy for patients with hormone receptor-positive (HR-positive) breast cancer is still unclear. This meta-analysis aims to determine the optimal duration of endocrine therapy with extended aromatase inhibitors (AI) for postmenopausal patients with HR-positive early breast cancer who have finished 5 years of endocrine therapy.

METHODS

Eligible randomized controlled trials were classified into three categories according to the whole duration of endocrine therapy (10 years versus 5 years, 7-8 years versus 5 years, and 10 years versus 7-8 years). For each category, hazard ratio (HR) for disease-free survival (DFS) and overall survival (OS), and risk ratio (RR) for the incidence of adverse events were pooled.

RESULTS

Altogether 9 RCTs enrolling a total of 22,313 postmenopausal women with HR-positive breast cancer were included. Pooled data showed an improvement in DFS when extending endocrine therapy from 5 to 7-8 years (HR = 0.79 [0.69, 0.91]), specifically among those who had been treated with only tamoxifen (HR = 0.40 [0.22, 0.73]) or sequential tamoxifen followed by AI (HR = 0.82 [0.71, 0.95]), with tumors that were node-positive (HR = 0.72 [0.56, 0.93]), estrogen receptor (ER) and progesterone receptor (PR) positive (HR = 0.61 [0.47, 0.78]), or ≥ 2 cm in size (HR = 0.72 [0.51, 0.98]). However, no improvement in DFS was obtained when extending from 7-8 to 10 years (HR = 0.98 [0.87, 1.11]). In addition, the extension of endocrine therapy was not associated with an improvement in OS, but was associated with an increased risk of bone fracture and osteopenia/osteoporosis.

CONCLUSION

Patients who have been treated with AI for 5 years, with tumors that are node-negative, ER+/PR- or ER-/PR+, and < 2 cm in size do not need to receive extended AI therapy. For those who have been treated with only tamoxifen or sequential tamoxifen followed by an AI for a total of 5 years, with tumors that are node-positive, ER+/PR+ or ≥ 2 cm in size, 2-3 years of extended AI is necessary and maybe enough.

The Evolving Complexity of Treating Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor-2 (HER2)-Negative Breast Cancer: Special Considerations in Older Breast Cancer Patients-Part I: Early-Stage Disease

The median age for breast cancer diagnosis is 62 years, but a disproportionate number of patients are over the age of 75 years and the majority of those have hormone receptor-positive, human epidermal growth factor receptor-2 (HER2)-negative cancers. This review provides a logical algorithm to guide providers through the many complicated issues involved in adjuvant systemic therapy decisions in older patients with hormone receptor-positive, HER2-negative breast cancer. For this subtype of breast cancer, the mainstay of treatment is surgery and adjuvant endocrine therapy with tamoxifen or an aromatase inhibitor (AI). Adjuvant chemotherapy is added to the treatment regimen when the benefits of treatment are deemed to outweigh the risks, making the risk-benefit discussion particularly important in older women. Traditional tools for cancer risk assessment and genomic expression profiles (GEPs) are under-utilized in older patients, but yield equally useful information about cancer prognosis as they do in younger patients. Additionally, there are tools that estimate life-limiting toxicity risk from chemotherapy and life expectancy, which are both important issues in the risk-benefit discussion. For very low-risk cancers, such as non-invasive and small lymph node (LN)-negative cancers, the benefits of any adjuvant therapy is likely outweighed by the risks, but endocrine therapy might be considered to prevent future new breast cancers. For invasive tumors that are > 5 mm (T1b or larger) or involve LNs, adjuvant endocrine therapy is recommended. Generally, AIs should be included, though tamoxifen is effective and should be offered when AIs are not tolerated. Bone-preserving agents and high-dose vitamin D are options to preserve bone density or treat osteoporosis, especially in older women who are taking AIs. Where the risk-reducing benefit from adjuvant chemotherapy outweighs the toxicity risk, adjuvant chemotherapy should be considered. Adjuvant chemotherapy has similar benefits in older and younger patients and standard regimens are preferred. Several exciting clinic trials are underway and have included older patients, including those adding molecularly targeted agents, cyclin-dependent kinase (CDK) 4/6 inhibitors and everolimus, to endocrine therapy in the adjuvant setting. The high incidence of breast cancer in older women should drive us to design clinical trials for this population and emphasize their inclusion in ongoing trials as much as possible.

Endocrine Therapy in Early Breast Cancer

Background

Endocrine therapy with a standard duration of 5 years is well known as an effective treatment for endocrine-sensitive breast cancer.

Summary

In the adjuvant setting this treatment reduces the 15-year mortality rates by about 30 and 40% with tamoxifen and aromatase inhibitor, respectively. The well-known long-term recurrence risk of luminal cancers led to multiple trials examining the benefit of extended endocrine treatment for up to 15 years. Additional benefit with extended therapy was seen for patients with high recurrence risk. Also, additional ovarian suppression for premenopausal women exhibited a significant benefit for patients at higher risk.

Key Messages

The data of the last years will be summarized and discussed, also considering the side effects of the different treatment options.

The effects of adjuvant hormonotherapy on tear functions in patients with breast cancer

PURPOSE

Aromatase inhibitors (anastrozole, letrozole) and selective estrogen receptor modulators (tamoxifen) are widely used as adjuvant hormonal therapy in women with hormone receptor-positive breast cancer. We aimed to evaluate the effects of oral adjuvant hormonotherapy on tear functions in patients with breast cancer.

METHODS

In this case-control study, we enrolled eligible patients with breast cancer who were receiving regular medical selective estrogen receptor modulator (tamoxifen, n:50), aromatase inhibitors (anastrozole, letrozole, n:50) and gender-matched healthy controls (n:50). Tear functions were measured and compared by the Schirmer test, fluorescein breakup time, corneal staining evaluated by Oxford grading scale and Ocular Surface Disease Index scores.

RESULTS

Mean age was 49.95 (± 9.2), 51.52 (± 7.2) and 51.91 (± 10.3) in tamoxifen, aromatase inhibitors groups and controls (p = 0.426). Mean duration of BC diagnosis (p = 0.536) and drug use (p = 0.417) was not significant between two groups. Ocular Surface Disease Index scores were lower (p < 0.001), and fluorescein breakup time measurements were higher (p < 0.001) in controls. Schirmer test scores were higher in controls than aromatase inhibitors group (p < 0.001). According to the scores of all measurements, the differences between aromatase inhibitors and tamoxifen groups were statistically significant (p < 0.001).

CONCLUSIONS

Our results demonstrated a high difference in all parameters in patients receiving aromatase inhibitors compared to tamoxifen group and controls. Aromatase inhibitors, which reduce estrogen levels in the blood, might affect the tear functions more than tamoxifen, which affects as antiestrogenic on estrogen receptors.