Efficacy of Single-Agent Chemotherapy in Endocrine Therapy-Refractory Metastatic Invasive Lobular Carcinoma

BACKGROUND

Hormone receptor (HR)-positive, HER2-negative metastatic invasive lobular breast cancer (mILC) is distinct from invasive ductal cancer (IDC) in clinicopathologic and molecular characteristics, impacting its response to systemic therapy. While endocrine therapy (ET) combined with targeted therapies has shown efficacy in ET-sensitive mILC, data on chemotherapy in ET-refractory mILC remain limited. We investigated the efficacy of single-agent capecitabine (CAP) versus taxanes (TAX) in ET-refractory HR+ HER2-negative patients with mILC.

MATERIALS AND METHODS

Using data from the MD Anderson prospectively collected breast cancer database, we identified patients with HR+ HER2-negative mILC who received prior ET and first-time chemotherapy in the metastatic setting. We compared outcomes between 173 CAP-treated and 96 TAX-treated patients.

RESULTS

CAP-treated patients had significantly better median progression-free survival (PFS) than TAX-treated patients (8.8 vs 5.0 months, HR 0.63, P < .001). Overall survival (OS) did not differ significantly between the groups (42.7 vs 36.6 months for CAP vs TAX, respectively, HR 0.84, P = .241). Multivariate analyses for PFS and OS revealed better outcomes in subjects with fewer metastatic sites and those exposed to more lines of ET. Additionally, Black patients showed worse OS outcomes compared to White patients (HR 2.46; P = .001).

CONCLUSION

In ET-refractory HR+ HER2-negative mILC, single-agent CAP demonstrated superior PFS compared to TAX. Our findings highlight the potential benefit of CAP in this patient subset, warranting further investigation through prospective trials.

Real World Experience of Second-Line Treatment Strategies after Palbociclib and Letrozole: Overall Survival in Metastatic Hormone Receptor-Positive Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer

BACKGROUND

We analyzed real-world practice of second-line treatment in hormone receptor (HR)+ human epidermal growth factor receptor-2 (HER2)- metastatic breast cancer (MBC) following the first-line CDK4/6 inhibitor with letrozole. In addition, we evaluated the relationship between second-line treatment strategies and survival outcome.

METHODS

Using the clinical data warehouse, clinical information including MBC diagnosis, treatment and survival outcomes were collected.

RESULTS

In total, 305 patients were treated with the first-line palbociclib plus letrozole, and we evaluated 166 patients who were treated with second-line treatment. Of the 166 patients, 28.5% were treated with capecitabine (C), followed by exemestane with everolimus (EE) (27.3%) or cytotoxic chemotherapy other than capecitabine (T) (18.8%) and fulvestrant-based treatment or endocrine monotherapy (F) (12.7%). Eighteen patients (10.9%) were enrolled in clinical trials (CT). With regard to treatment strategies, and the median progression-free survival of second-line treatment in a metastatic setting (PFS2) was 7.4 months with C, 5.2 months with EE, 4.8 months with T, 3.6 months with F, and 3.6 months with CT (p = 0.066). In patients with visceral organ disease progression, C (31.3%) or T(31.3%) was the most common second-line treatment followed by EE (21.9%). Most of the 47 patients with bone metastasis alone were treated with EE (38.2%), followed by C (23.4%) and F (21.3%) (p = 0.008). The median overall survival of second-line treatment in a metastatic setting (OS2) was 42.3 months with C, 35.7 months with F, 30.7 months with EE, and 23.1 months with T. The median OS2 for those in CT was not reached (p = 0.064). ER driven BC, disease progression site and PFS2 were associated with OS and OS2 in HR+HER2- MBC (ps < 0.05).

CONCLUSIONS

We suggested the second line treatment strategy was important to improve prognosis in patients with HR+/HER2- MBC, especially given the recent standardization of first-line treatment and the many available second-line options.

Prognostic Value of SGK1 and Bcl-2 in Invasive Breast Cancer

It is crucial to understand molecular alterations in breast cancer and how they relate to clinicopathologic factors. We have previously shown that the glucocorticoid receptor (GCR) protein expression was reduced in invasive breast carcinoma compared to normal breast tissue. Glucocorticoids, signaling through the GCR, regulate several cellular processes via downstream targets such as serum/glucocorticoid-regulated kinase 1 (SGK1) and B-cell lymphoma 2 (Bcl-2). We measured the expression of SGK1 and Bcl-2, in respective breast cancer tissue arrays, from a multiracial cohort of breast cancer patients. Higher cytoplasmic SGK1 staining was stronger in breast cancer tissue compared to normal tissue, especially in hormone receptor-negative cases. Conversely, the expression of cytoplasmic Bcl-2 was reduced in breast cancer compared to normal tissue, especially in hormone receptor-negative cases. Bcl-2 staining was associated with the self-reported racial/ethnic category, an earlier clinical stage, a lower histological grade, and a higher survival rate. Bcl-2 expression was associated with longer survival in models adjusted for age and race (HR = 0.32, 95% CI: 0.15, 0.65), and Bcl-2 expression remained strongly positively associated with protection from breast cancer death, with additional adjustments for ER/PR status (HR = 0.41, 95% CI: 0.2, 0.85). SGK1 and Bcl-2 may play biological roles in breast cancer development and/or progression.

Identifying the optimal therapeutics for patients with hormone receptor-positive, HER2-positive advanced breast cancer: a systematic review and network meta-analysis

INTRODUCTION

Hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-positive (HER2+) breast cancer is a distinct subtype with different prognosis and response to treatment. HER2-targeted therapy is currently recommended for patients with HR+/HER2+ advanced breast cancer. However, there is debate over which drugs to add on the basis of HER2 blockade yield the optimal efficacy. This systematic review and network meta-analysis was conducted to solve the problem.

METHODS

Eligible randomized controlled trials (RCTs) comparing different interventions in HR+/HER2+ metastatic breast cancer were included. The outcomes of interest included progression-free survival (PFS), overall survival (OS) and treatment-related adverse events (TRAEs). Pooled hazard ratios or odds ratios with credible intervals (CrIs) were calculated to estimate the predefined outcomes. The optimal therapeutics were identified by comparing the surface under the cumulative ranking curves (SUCRA).

RESULTS

Totally, 23 literatures of 20 RCTs were included. Regarding PFS, significant differences were detected between single or dual HER2 blockade plus endocrine therapy (ET) versus ET alone and dual HER2 blockade plus ET versus physician's choice. Trastuzumab, pertuzumab plus chemotherapy significantly improved PFS than trastuzumab plus chemotherapy (hazard ratio 0.69, 95% CrI 0.50-0.92). The SUCRA values suggested the relatively better efficacy of dual HER2-targeted therapy plus ET (86%-91%) than chemotherapy (62%-81%) in prolonging PFS and OS. The HER2 blockade-containing regimens showed similar safety profiles in eight documented TRAEs.

CONCLUSIONS

Prominent status of dual-targeted therapy for patients with HR+/HER2+ metastatic breast cancer was revealed. Compared with chemotherapy-containing regimens, the ET-containing ones showed better efficacy and similar safety profiles, which could be recommended in clinical practice.

Genomic characterisation of hormone receptor-positive breast cancer arising in very young women

BACKGROUND

Very young premenopausal women diagnosed with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+HER2-) early breast cancer (EBC) have higher rates of recurrence and death for reasons that remain largely unexplained.

PATIENTS AND METHODS

Genomic sequencing was applied to HR+HER2- tumours from patients enrolled in the Suppression of Ovarian Function Trial (SOFT) to determine genomic drivers that are enriched in young premenopausal women. Genomic alterations were characterised using next-generation sequencing from a subset of 1276 patients (deep targeted sequencing, n = 1258; whole-exome sequencing in a young-age, case-control subsample, n = 82). We defined copy number (CN) subgroups and assessed for features suggestive of homologous recombination deficiency (HRD). Genomic alteration frequencies were compared between young premenopausal women (<40 years) and older premenopausal women (≥40 years), and assessed for associations with distant recurrence-free interval (DRFI) and overall survival (OS).

RESULTS

Younger women (<40 years, n = 359) compared with older women (≥40 years, n = 917) had significantly higher frequencies of mutations in GATA3 (19% versus 16%) and CN amplifications (CNAs) (47% versus 26%), but significantly lower frequencies of mutations in PIK3CA (32% versus 47%), CDH1 (3% versus 9%), and MAP3K1 (7% versus 12%). Additionally, they had significantly higher frequencies of features suggestive of HRD (27% versus 21%) and a higher proportion of PIK3CA mutations with concurrent CNAs (23% versus 11%). Genomic features suggestive of HRD, PIK3CA mutations with CNAs, and CNAs were associated with significantly worse DRFI and OS compared with those without these features. These poor prognostic features were enriched in younger patients: present in 72% of patients aged <35 years, 54% aged 35-39 years, and 40% aged ≥40 years. Poor prognostic features [n = 584 (46%)] versus none [n = 692 (54%)] had an 8-year DRFI of 84% versus 94% and OS of 88% versus 96%. Younger women (<40 years) had the poorest outcomes: 8-year DRFI 74% versus 85% and OS 80% versus 93%, respectively.

CONCLUSION

These results provide insights into genomic alterations that are enriched in young women with HR+HER2- EBC, provide rationale for genomic subgrouping, and highlight priority molecular targets for future clinical trials.

Post-CDK 4/6 Inhibitor Therapy: Current Agents and Novel Targets

Front-line therapy for advanced and metastatic hormone receptor positive (HR+), HER2 negative (HER-) advanced or metastatic breast cancer (mBC) is endocrine therapy with a CDK4/6 inhibitor (CDK4/6i). The introduction of CDK4/6i has dramatically improved progression-free survival and, in some cases, overall survival. The optimal sequencing of post-front-line therapy must be personalized to patients' overall health and tumor biology. This paper reviews approved next lines of therapy for mBC and available data on efficacy post-progression on CDK4/6i. Given the success of endocrine front-line therapy, there has been an expansion in therapies under clinical investigation targeting the estrogen receptor in novel ways. There are also clinical trials ongoing attempting to overcome CDK4/6i resistance. This paper will review these drugs under investigation, review efficacy data when possible, and provide descriptions of the adverse events reported.

Efficacy and safety of endocrine therapy after mastectomy in patients with hormone receptor positive breast ductal carcinoma in situ: Retrospective cohort study

Background

More than half of Chinese patients with hormone receptor positive (HR+) ductal carcinoma in situ (DCIS) are treated with mastectomy, and usually subjected to postoperative endocrine therapy (ET). Given that long-term ET can cause severe adverse effects it is important to determine the beneficial effect and safety of post-mastectomy ET on the disease-free survival (DFS) and adverse events in patients with HR+ DCIS.

Methods

To explore beneficial effect and safety of post-mastectomy ET in patients with HR+ DCIS, we performed a multicenter, population-based study. This retrospective study analyzed the DFS and adverse events in 1037 HR+ DCIS Chinese patients with or without post-mastectomy ET from eight breast centers between 2006 and 2016. The median follow-up time period was 86 months.

Results

There were 791 DCIS patients receiving ET (ET group). Those patients were followed up for a median of 86 months (range, 60-177 months). There were 23 cases with tumor recurrence or distant metastasis. There were similar 5-year DFS rates and DFS between the ET and non-ET groups, even for those with high-risk factors. Conversely, 37.04% of patients suffered from adverse events after ET, which were significantly higher than those in the non-ET group.

Conclusions

ET after mastectomy did not benefit patients with HR+ DCIS for their DFS, rather increased adverse events in those patients. Therefore, ET after mastectomy may not be recommended for patients with HR+ DCIS, even for those with high-risk factors, such as multifocal, microinvasive, and higher T stage.

Funding

This study was supported by grants from Outstanding Scientific Fund of Shengjing Hospital (201803) and Outstanding Young Scholars of Liaoning Province (2019-YQ-10).

Phase II Study Combining Pembrolizumab with Aromatase Inhibitor in Patients with Metastatic Hormone Receptor Positive Breast Cancer

This study investigated the safety and antitumor activity of aromatase inhibitors (AI) with immune checkpoint inhibitor (ICI) pembrolizumab in patients with hormone receptor positive (HR⁺) human epidermal growth factor receptor 2-negative (HER2^-) metastatic breast cancer (MBC) in a phase II study with a safety lead-in (NCT02648477). Patients received pembrolizumab plus AI up to 2 years or until confirmed progression or unacceptable toxicity. Key eligibility criteria were HR⁺ HER2^- MBC; RECIST v1.1 measurable disease; adequate organ function; and ECOG 0-1. Primary endpoints were safety and overall response rate. A 3-at-risk design was used for the safety lead-in with a targeted accrual of 20 patients. Grade 2 adverse events (AEs) included 35% fatigue, 20% rash, and 10% hot flashes. Grade 3 immune-related AEs (irAEs) related to pembrolizumab included 5% elevated AST/ALT, 5% rash, and 5% lymphopenia. Two (10%) patients had partial responses, three (15%) had stable disease, and 15 (75%) had progression of disease. Median progression-free survival was 1.8 months (95% CI 1.6, 2.6), median overall survival was 17.2 months (95% CI 9.4, NA), and median follow-up time was 40.1 months (range 31.3-46.8 months). The combination was well tolerated, but clinical activity was comparable to AI alone.

Prognostic Significance of Low HER2 Expression in Patients With Metastatic Hormone Receptor-positive Breast Cancer Treated With First Line CDK4/6 Inhibitors: A Greek Multicenter Real-world Data Analysis

BACKGROUND/AIM

Low expression of HER2 has defined a new "HER2-low" subgroup of breast cancer with distinct clinicopathological characteristics and both prognostic and predictive implications. The impact of low HER2 expression in metastatic hormone receptor-positive HER2-negative breast cancer treated with first-line CDK4/6 inhibitors has not been studied. Using real-world patient data, we aimed to identify prognostic differences in this patient population according to HER2 expression with immunohistochemistry.

PATIENTS AND METHODS

We retrospectively analyzed 191 patients from 5 Oncology Department databases in Thessaloniki, Greece, with hormone receptor-positive HER2-negative metastatic breast cancer treated with CDK4/6 inhibitors in the first line, for whom detailed immunohistochemical HER2 data could be retrieved.

RESULTS

Median progression-free survival was numerically different among the different HER2 subgroups (3.35 years for HER2 0 tumors, 2.18 years for HER2 +1 tumors, 1.74 years for HER2 +2/ISH-negative tumors), but this difference was not statistically significant (p=0.477). Median PFS was statistically significantly longer in patients without visceral metastases (5.45 years) compared to patients with visceral metastases (1.61 years) (p=0.017). Median PFS was also statistically significantly longer in patients taking an aromatase inhibitor (2.99 years) compared to patients taking fulvestrant (1.33 years) (p<0.0001). There were no statistically significant differences in the other subgroups examined.

CONCLUSION

CDK4/6 inhibitors are equally effective as first-line treatment agents, regardless of the exact level of HER2 expression. Numerical differences, however, do exist among the different HER2 subgroups, and merit further evaluation in future studies to better study this phenomenon.

Effect of Bevacizumab on a Human Breast Cancer Model that Exhibited Palbociclib-resistance by RB Knockout

BACKGROUND/AIM

Although CDK4/6 inhibitors have been increasingly used in combination with hormonal agents to treat hormone-receptor positive and human epithelial growth factor receptor 2-negative breast cancer, the mechanism of CDK4/6 inhibitor resistance and its impact on established therapy for post-resistance, especially bevacizumab combined with chemotherapy, are unclear.

MATERIALS AND METHODS

Sensitivity of RB knockout MCF7 clones to CDK4/6 inhibitors was evaluated in vitro. One RB knockout clone was subcutaneously implanted in nude mice and the effects of bevacizumab on volume and microvessel density (MVD) of tumors were investigated.

RESULTS

Palbociclib did not exhibit antitumor efficacy against the RB knockout tumor, in contrast to the parental MCF7 xenograft model. Bevacizumab significantly exhibited antitumor efficacy and suppressed the MVD both in RB knockout and parental MCF7 xenograft models.

CONCLUSION

Bevacizumab inhibited tumor growth by suppressing MVD in the CDK4/6 inhibitor-resistant tumor acquired due to RB loss, suggesting its efficacy also in patients after treatment with CDK4/6 inhibitors.

Effect of concomitant statin treatment in postmenopausal patients with hormone receptor-positive early-stage breast cancer receiving adjuvant denosumab or placebo: a post hoc analysis of ABCSG-18

Background

Statins are cholesterol-lowering drugs prescribed for the prevention and treatment of cardiovascular disease. Moreover, statins may possess anticancer properties and interact with receptor activator of nuclear factor κB ligand expression. We aimed at evaluating a hypothetical synergistic effect of statins with denosumab in early-stage breast cancer (BC) patients from the Austrian Breast and Colorectal Cancer Study Group (ABCSG) trial 18.

Patients and methods

ABCSG-18 (NCT00556374) is a prospective, randomized, double-blind, phase III study; postmenopausal patients with hormone receptor-positive BC receiving a nonsteroidal aromatase inhibitor were randomly assigned to denosumab or placebo. In this post hoc analysis, we investigated the effects of concomitant statin therapy on recurrence risk (RR) of BC, fracture risk and bone mineral density (BMD).

Results

In the study population (n = 3420), statin therapy (n = 824) was associated with worse disease-free survival (DFS) [hazard ratio (HR) 1.35, 95% confidence interval (CI) 1.04-1.75; P = 0.023]. While no significant effect of lipophilic statins (n = 710) on RR was observed (HR 1.30, 95% CI 0.99-1.72; P = 0.062), patients on hydrophilic statins (n = 87) had worse DFS compared with patients not receiving any statins (HR 2.00, 95% CI 1.09-3.66; P = 0.026). This finding was mainly driven by the effect of hydrophilic statins on DFS in the denosumab arm (HR 2.63, 95% CI 1.21-5.68; P = 0.014). However, this effect subsided after correction for confounders in the sensitivity analysis. No association between statin use and fracture risk or osteoporosis was observed.

Conclusion

According to this analysis, hydrophilic statins showed a detrimental effect on DFS in the main model, which was attenuated after correction for confounders. Our data need to be interpreted with caution due to their retrospective nature and the low number of patients receiving hydrophilic statins.

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Statin co-medication was initially associated with a worse DFS in hormone receptor-positive early-stage BC patients.

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This effect was mainly driven by patients on hydrophilic statins.

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However, this effect subsided after correction for confounders in the sensitivity analysis.

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No association between statin use and fracture risk or osteoporosis was observed.

Adjuvant tamoxifen adherence in men with early-stage breast cancer

BACKGROUND

Most breast cancers (BCs) in men are hormone receptor-positive. Adjuvant tamoxifen is part of the standard treatment of these patients. Small, single-institution studies have suggested that men have high rates of discontinuing adjuvant endocrine treatment. The authors examined rates of tamoxifen discontinuation and medication adherence in a large population-based cohort of male patients with BC.

METHODS

In the Surveillance, Epidemiology, and End Results-Medicare database, male patients with invasive nonmetastatic BC, diagnosed between 2007 and 2013, who were ≥65 years old, had Part D coverage, and had tamoxifen prescriptions within 1 year of diagnosis were identified. Adherence was defined as a medication possession ratio of ≥80% among those patients who were filling tamoxifen prescriptions. Logistic regression model was used to assess predictors of tamoxifen adherence.

RESULTS

A total of 451 patients met eligibility criteria. The median age at diagnosis was 75 years. The median follow-up was 32.5 months. The rates of tamoxifen discontinuation were 15.8%, 24.3%, 31.3%, 36.9%, and 48.3% at 1, 2, 3, 4, and 5 years after diagnosis, respectively. Among the men who were still taking tamoxifen, the corresponding adherence rates were 76.9%, 73.6%, 68.7%, 64.8%, and 60.2%. In the adjusted model, significant predictors of lower adherence included residing in a high poverty area (odds ratio [OR], 0.77; 95% confidence interval [CI], 0.28-2.12) and a Charlson comorbidity score of ≥2 (OR, 0.46; 95% CI, 0.22-0.97).

CONCLUSION

Older men with breast cancer have high rates of tamoxifen discontinuation, with 48% of all patients discontinuing tamoxifen before the end of year 5. Additionally, even among those patients continuing tamoxifen, a substantial number of patients are nonadherent. Further research should evaluate potentially modifiable reasons for treatment discontinuation and lack of adherence to tamoxifen.

Cumulative menstrual months and breast cancer risk by hormone receptor status and ethnicity: The Breast Cancer Etiology in Minorities Study

Reproductive and hormonal factors may influence breast cancer risk via endogenous estrogen exposure. Cumulative menstrual months (CMM) can be used as a surrogate measure of this exposure. Using harmonized data from four population-based breast cancer studies (7284 cases and 7242 controls), we examined ethnicity-specific associations between CMM and breast cancer risk using logistic regression, adjusting for menopausal status and other risk factors. Higher CMM was associated with increased breast cancer risk in non-Hispanic Whites, Hispanics and Asian Americans regardless of menopausal status (all FDR adjusted P trends = .0004), but not in African Americans. In premenopausal African Americans, there was a suggestive trend of lower risk with higher CMM. Stratification by body mass index (BMI) among premenopausal African American women showed a nonsignificant positive association with CMM in nonobese (BMI <30 kg/m² ) women and a significant inverse association in obese women (OR per 50 CMM = 0.56, 95% CI 0.37-0.87, P_trend  = .03). Risk patterns were similar for hormone receptor positive (HR+; ER+ or PR+) breast cancer; a positive association was found in all premenopausal and postmenopausal ethnic groups except in African Americans. HR- (ER- and PR-) breast cancer was not associated with CMM in all groups combined, except for a suggestive positive association among premenopausal Asian Americans (OR per 50 CMM = 1.33, P = .07). In summary, these results add to the accumulating evidence that established reproductive and hormonal factors impact breast cancer risk differently in African American women compared to other ethnic groups, and also differently for HR- breast cancer than HR+ breast cancer.

Capecitabine in Combination with Endocrine Therapy as Maintenance Therapy after Bevacizumab Plus Paclitaxel Induction Therapy for Hormone Receptor-Positive, HER2-Negative Metastatic Breast Cancer: KBCSG-TR1214

Simple Summary

To investigate a possible treatment strategy for hormone receptor (HR)-positive, HER2-negative advanced and/or metastatic breast cancer (AMBC), we investigated the clinical usefulness of adding capecitabine to maintenance endocrine therapy after induction chemotherapy and the efficacy of reinduction chemotherapy. Patients who had received bevacizumab–paclitaxel induction therapy and did not have progressive disease were randomized to receive maintenance therapy with endocrine therapy alone (group E; n = 46) or endocrine therapy plus capecitabine (group EC; n = 44). The median progression-free survival (PFS) under maintenance therapy (primary endpoint) was significantly longer in group EC than in group E (11.1 vs. 4.3 months; hazard ratio, 0.53; p < 0.01). At 24 months from the induction therapy start, the overall survival (OS) rate was significantly higher in group EC than in group E (83.5% vs. 62.3%; p = 0.02). Therefore, the addition of capecitabine to maintenance endocrine therapy may be a beneficial option after induction chemotherapy for HR-positive, HER2-negative AMBC patients.

Abstract

Optimal treatment strategies for hormone receptor (HR)-positive, HER2-negative advanced and/or metastatic breast cancer (AMBC) remain uncertain. We investigated the clinical usefulness of adding capecitabine to maintenance endocrine therapy after induction chemotherapy and the efficacy of reinduction chemotherapy. Patients who had received bevacizumab–paclitaxel induction therapy and did not have progressive disease (PD) were randomized to maintenance therapy with endocrine therapy alone (group E) or endocrine plus capecitabine (1657 mg/m²/day on days 1–21, q4w) (group EC). In case of PD after maintenance therapy, patients received bevacizumab–paclitaxel reinduction therapy. Ninety patients were randomized. The median progression-free survival (PFS) under maintenance therapy (primary endpoint) was significantly longer in group EC (11.1 {95% CI, 8.0–11.8} months) than in group E (4.3 {3.6–6.0} months) (hazard ratio, 0.53; p < 0.01). At 24 months from the induction therapy start, the overall survival (OS) was significantly longer in group EC than in group E (hazard ratio, 0.41; p = 0.046). No difference was found in the time to failure of strategy (13.9 and 16.6 months in groups E and EC, respectively). Increased capecitabine-associated toxicities in group EC were tolerable. Addition of capecitabine to maintenance endocrine therapy may be a beneficial option after induction chemotherapy for HR-positive, HER2-negative AMBC patients.

Association of Obesity with Breast Cancer Outcome in Relation to Cancer Subtypes: A Meta-Analysis

Background

Obesity at breast cancer (BC) diagnosis has been associated with poor outcome, although the magnitude of effect in different BC subtypes is uncertain. We report on the association of obesity or overweight at diagnosis of nonmetastatic BC with disease-free (DFS) and overall survival (OS) in the following defined subtypes: hormone receptor positive/HER2 negative (HR+HER2−), HER2 positive (HER2+), and triple negative (TNBC).

Methods

We searched MEDLINE, EMBASE, and COCHRANE databases up to January 1, 2019. Study eligibility was performed independently by 2 authors. Studies reporting hazard ratios (HRs) of OS and/or DFS for obesity or overweight in BC subtypes were included. The pooled hazard ratio was computed and weighted using generic inverse variance and random effects models.

Results

Twenty-seven studies were included. Obese compared with nonobese women had worse DFS in all subtypes: the hazard ratios were 1.26 (95% confidence interval [CI] = 1.13 to 1.41, P < .001) for HR+HER2− BC, 1.16 (95% CI = 1.06 to 1.26, P < .001) for HER2+ BC, and 1.17 (95% CI = 1.06 to 1.29, P = .001) for TNBC. OS was also worse in obese vs nonobese women (HR+HER2− BC HR = 1.39, 95% CI = 1.20 to 1.62, P < .001; HER2+ BC HR = 1.18, 95% CI = 1.05 to 1.33, P = .006; and TNBC HR = 1.32, 95% CI = 1.13 to 1.53, P < .001). As opposed to obesity, overweight was not associated with either DFS or OS in HER2+ BC (HR = 1.02, 95% CI = 0.81 to 1.28, P = .85; and HR = 0.96, 95% CI = 0.76 to 1.21, P = .99, respectively) or TNBC (HR = 1.04, 95% CI = 0.93 to 1.18, P = .49; and HR = 1.08, 95% CI = 0.81 to 1.44, P = .17), respectively. In HR+HER2− BC, being overweight was associated with worse OS (HR = 1.14, 95% CI = 1.07 to 1.22, P < .001).

Conclusions

Obesity was associated with modestly worse DFS and OS in all BC subtypes.

The Effect of Subsequent Pregnancy on Prognosis in Young Breast Cancer Patients (≤35 Years Old) According to Hormone Receptor Status

Purpose

We aimed to examine the effect of pregnancy on prognosis in young breast cancer (YBC) patients with hormone receptor (HR) positive after surgery and the safety of interrupting endocrine therapy (ET).

Methods

A retrospective cohort study was performed in patients who became pregnant after BC surgery under the age of 35 and were matched (1:4) to nonpregnant patients from 2006 to 2014. The primary endpoints were disease-free survival (DFS) and overall survival (OS) in HR-positive BC patients, and the secondary endpoints were DFS and OS in HR-negative BC patients and the whole population. Subgroup analyses included the DFS of patients who became pregnant within 5 years after surgery and DFS according to the ET interval time (≤ 30 months v > 30 months) in the pregnant group.

Results

A total of 1323 YBC patients were collected in our study, which included 68 pregnant patients and 264 matched nonpregnant patients. There were no statistically significant differences in DFS and OS among HR-positive patients (P=0.657, P=0.250, respectively) and the whole population (P=0.058, P=0.152, respectively). A BC pregnancy interval ≤ 5 years showed a better DFS (P=0.042), and an ET interval ≤ 30 months had a worse DFS (P = 0.01).

Conclusion

This study did not observe a worse prognosis in patients with HR-positive disease who became pregnant after BC surgery, and an ET interval less than 30 months in pregnant patients led to a worse outcome. Patients were able to become pregnant within 5 years after surgery.

Hormone Receptor Positive/HER2 Negative Breast Cancer With Isolated Bladder Metastasis: A Rare Case

Breast cancer is the most common cancer diagnosed in women in North America. Hormone receptor positive (HR+) and HER2 negative (HER2-) breast cancers account for at least 60% to 70% of all breast cancer cases. They usually metastasize to lymph nodes, bones, liver, lungs, and brain. Urinary bladder is a very unusual site for metastatic HR+/HER2- breast cancer and occurs in only 2% of all metastatic disease. In this article, we present a case of a 63-year-old female with locally advanced breast cancer who underwent mastectomy, adjuvant chemotherapy, radiation, and hormonal therapy. She was in remission for almost 17 years and subsequently presented with hematuria and lower abdominal pain. Cystoscopy was performed, which showed evidence of bladder wall thickening. Histopathology showed metastatic HR+/HER2- breast cancer consistent with her history of breast primary. Imaging studies did not show any other evidence of metastatic disease. She was started on cyclin D kinase 4/6 inhibitor, palbociclib, in combination with an aromatase inhibitor, letrozole. This is an exceedingly rare case of HR+ and HER2- breast cancer with metastasis to the urinary bladder. The late onset of recurrence with bladder metastasis makes this case very unique and to our knowledge only few similar cases have been reported in the literature.

Impact of Different Modules of 21-Gene Assay in Early Breast Cancer Patients

BACKGROUND

The 21-gene assay recurrence score (RS) provides additional information on recurrence risk of breast cancer patients and prediction of chemotherapy benefit. Previous studies that examined the contribution of the individual genes and gene modules of RS were conducted mostly in postmenopausal patients. We aimed to evaluate the gene modules of RS in patients of different ages.

METHODS

A total of 1,078 estrogen receptor (ER)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer patients diagnosed between January 2009 and March 2017 from Shanghai Jiao Tong University Breast Cancer Data Base were included. All patients were divided into three subgroups: Group A, ≤40 years and premenopausal (n = 97); Group B, >40 years and premenopausal (n = 284); Group C, postmenopausal (n = 697). The estrogen, proliferation, invasion, and HER2 module scores from RS were used to characterize the respective molecular features. Spearman correlation and analysis of the variance tests were conducted for RS and its constituent modules.

RESULTS

In patients >40 years, RS had a strong negative correlation with its estrogen module (ρ = -0.76 and -0.79 in Groups B and C) and a weak positive correlation with its invasion module (ρ = 0.29 and 0.25 in Groups B and C). The proliferation module mostly contributed to the variance in young patients (37.3%) while the ER module contributed most in old patients (54.1% and 53.4% in Groups B and C). In the genetic high-risk (RS >25) group, the proliferation module was the leading driver in all patients (ρ = 0.38, 0.53, and 0.52 in Groups A, B, and C) while the estrogen module had a weaker correlation with RS. The impact of ER module on RS was stronger in clinical low-risk patients while the effect of the proliferation module was stronger in clinical high-risk patients. The association between the RS and estrogen module was weaker among younger patients, especially in genetic low-risk patients.

CONCLUSIONS

RS was primarily driven by the estrogen module regardless of age, but the proliferation module had a stronger impact on RS in younger patients. The impact of modules varied in patients with different genetic and clinical risks.

Cost-Effectiveness of Ribociclib for Hormone Receptor-Positive HER2-Negative Advanced Breast Cancer

PURPOSE

Ribociclib has provided significant improvements in progression-free survival (PFS) and overall survival (OS) of postmenopausal patients with hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC). However, given the high cost of ribociclib, its value must be evaluated based on cost-effectiveness. Thus, we aimed to explore the cost-effectiveness of ribociclib for postmenopausal patients with HR-positive and HER2-negative ABC.

METHODS

A comprehensive Markov model was developed to estimate the cost-effectiveness of ribociclib plus fulvestrant versus placebo plus fulvestrant as first-line treatment for HR-positive, HER2-negative ABC. Variables were estimated based on data from the randomized Phase III MONALEESA-3 trial. Ten-year values were estimated for quality-adjusted life years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs). Direct treatment costs were estimated from the perspective of a United States payer. One-way and probabilistic sensitivity analyses were conducted to confirm the model's robustness.

RESULTS

Ribociclib plus fulvestrant increased the treatment cost by $382,172 and provided 0.47 QALYs, relative to fulvestrant alone, which corresponded to an ICER of $813,132 per QALY. Sensitivity analyses revealed that ribociclib was unlikely to be cost-effective even under the most favorable assumptions. When the cost of ribociclib was <$1,384, there was a >50% chance of cost-effectiveness at a willingness-to-pay threshold of $150,000/QALY. Subgroup analyses also confirmed that ribociclib was not cost-effective.

CONCLUSION

At current drug prices in the United States, ribociclib is unlikely to be cost-effective for treating postmenopausal patients with HR-positive HER2-negative ABC. Despite the clinical benefits of ribociclib, its cost would need to decrease to provide more favorable economic outcomes.

Abemaciclib, a third CDK 4/6 inhibitor for the treatment of hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced or metastatic breast cancer

INTRODUCTION

The field of metastatic luminal breast cancer (hormone receptor positive, HER-2 negative) is dynamic and evolving, harboring some of the most significant therapeutic advances in medical oncology. Over the last decade, many pivotal trials showed excellent results with drastic improvements in survival as well as the quality of life of metastatic luminal breast cancer patients.

AREAS COVERED

The successful inhibition of the cyclinD/cyclin-dependent kinases 4 and 6 (CDK4/6)-retinoblastoma protein (RB) pathway with potent CDK4/6 inhibitors improved the outcome of advanced luminal breast cancers. Abemaciclib is the third CDK 4/6 inhibitor arriving to the market after palbociclib and ribociclib. Here, we describe the biology of the CDK4/6 pathway and summarize clinical data of previously published pivotal trials emphasizing the efficacy and toxicity of abemaciclib. The aim was to define its place in the current guidelines and to make a brief comparison with other available drugs of same class in the absence of cross trials comparison.

EXPERT OPINION

As there are no available biomarkers to predict response or resistance to abemaciclib, the promising overall survival data of MONARCH-2 could possibly impact the clinician's choice to optimize treatment for endocrine-resistant metastatic breast cancer.

Tumour-Infiltrating Inflammatory Cells in Early Breast Cancer: An Underrated Prognostic and Predictive Factor?

The role of tumour-infiltrating inflammatory cells (TIICs) in the disease progression of hormone-receptor-positive breast cancer (HR+ BC) is largely unclear since it is generally regarded as the least immunogenic BC subtype. This study investigated the prognostic significance of CD1a+ dendritic cells, CD20+ B cells, CD45RO+ memory T cells and CD4+ T-helper cells in HR+ BC. One hundred and forty-six patients were treated for early stage, distant-metastases-free HR+ BC in an accelerated partial breast irradiation (APBI) phase II trial. Immunohistochemistry was used to double-stain two adjoining sets of tissue microarrays from pre-RT (radiotherapy) tumour resection samples for CD1a/CD20 and CD45RO/CD4. Cell densities of CD1a+, CD20+, CD45RO+ and CD4+ TIICs in the stromal and intraepithelial compartment were registered semiautomatically. High densities of CD20+ and CD4+ TIICs were strongly associated with reduced disease-free survival (DFS), while high stromal CD45RO+ TIIC densities were indicators of subsequent successful treatment. An immunoscore based on CD20+ and CD45RO+ TIIC densities identified three different risk groups (p < 0.001). Thus, contrary to current assumptions, intratumoural immune cell composition might be an important prognostic indicator and a possible contributing factor in the outcome of HR+ BC and should be the subject of further research. Specifically, B-cell infiltration entailed an increased relapse rate and could play an important role in disease progression.

Palbociclib and beyond for the treatment of HR + HER2- metastatic breast cancer: an Asian-Pacific perspective and practical management guide on the use of CDK4/6 inhibitors

Breast cancer is the most frequent cancer amongst women worldwide including in Asia where the incidence rate is rapidly increasing. Even with treatment, around 30% of patients with early breast cancer progress to metastatic disease, with hormone receptor positive (HR+) and human epidermal growth factor receptor 2 negative (HER2-) breast cancer the most common phenotype. First-line endocrine therapy targeting the estrogen receptor signaling pathway provides a median progression-free survival or time to progression of 6-15 months in HR + HER2- metastatic breast cancer. Recently, cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors, combined with endocrine therapy, have achieved more than two years median progression-free survival in HR + HER2- metastatic breast cancer. However, the characteristics of the Asian breast cancer population differ from those of Western populations and need to be considered when selecting a suitable treatment. Breast cancer is diagnosed at a younger age in Asian populations and late stage at presentation is generally more common in low-/middle-income countries than high-income countries. Consequently, the proportion of premenopausal women with metastatic breast cancer is higher in Asian compared with Western populations. While CDK4/6 inhibitors have been approved in the USA (FDA) since 2015, experience with them in Asia is more limited. We review the experience with the CDK4/6 inhibitor palbociclib in Asian patients with HR + HER2- metastatic breast cancer and provide guidance on the use of palbociclib in these patients.

Endocrine and Targeted Therapy for Hormone-Receptor-Positive, HER2-Negative Advanced Breast Cancer: Insights to Sequencing Treatment and Overcoming Resistance Based on Clinical Trials

Background: Advanced hormone-receptor positive HER2 negative breast cancer is a common and a very heterogeneous disease. Hormone therapy is the main first line treatment of choice, given alone or in combination with other agents that have shown to improve patient outcomes, Nevertheless, treatment remains generally palliative rather than curative. Sequencing of such treatment remains challenging, especially with resurgence of variable resistance patterns. Multiple attempts have been made to overcome resistance and improve patient survival, yet resistance remains not very well understood and metastatic cancer remains a disease with dismal prognosis.

Methods: In this paper, we searched pubmed database as well as local and international meetings for all studies discussing advanced and metastatic hormone-receptor-positive, her2-negative breast cancer, hormonal treatment, resistance to hormonal treatment, mechanism of resistance, and means to overcome such resistance.

Conclusion: There does not exist an optimal treatment sequence for hormone-receptor-positive, her2-negative advanced breast cancer. However, after review of literature, a reasonable approach may be starting with tamoxifen, aromatase inhibitors, or fulvestrant in absence of visceral crisis, in addition to ensuring adequate ovarian function suppression in pre/peri-menopausal women. Aromatase inhibitors and fulvestrant seem to be superior. Resistance to such agents is increasing, mostly attributed to genetic and molecular changes. Multiple modalities are addressed to overcome such resistance including use of CKD4/6 inhibitors, mTOR inhibitors and PI3K inhibitors in addition to other agents under study, all with promising results. CDK4/6 inhibitors work best when used in frontline setting. Finally, treatment of breast cancer remains a growing field, and more studies are to be awaited.

CDK4-6 inhibitors in breast cancer: current status and future development

INTRODUCTION

Aberrant cellular proliferation due to dysregulation of the cyclin-dependent kinase (CDK) retinoblastoma (Rb)-pathway occurs in several cancers. Selective inhibition of CDK4/6 is an attractive target particularly in hormone-receptor positive (HR+) metastatic breast cancer (MBC), where it has transformed the treatment of these cancers in recent years. Three CDK4/6 inhibitors, palbociclib, ribociclib, and abemaciclib, have been approved for the treatment of HR+, HER2 negative (HER2-) MBC. Areas covered: We reviewed and compared the pharmacology, clinical efficacy, and toxicity profiles of the three CDK4/6 inhibitors and discussed several challenges in the use of these drugs, particularly in identifying biomarkers, optimizing dosing strategies, and finding best combinations with other therapies. Expert opinion: All three CDK4/6 inhibitors have shown remarkable efficacy when added to endocrine therapy in the treatment of HR+/HER2- MBC with consistent improvements in progression-free survival across all phase III trials. As efficacy appears similar between the drugs, differences in toxicities, dosing schedule, and monitoring requirements may influence the choice of CDK4/6 inhibitor. There is a paucity of predictive biomarkers that have been identified thus far, but a few promising biomarkers have been studied in the preclinical setting and results of ongoing clinical studies are awaited to validate their utility.

Optimising endocrine therapy in postmenopausal women with advanced breast cancer

Hormone receptor-positive breast cancer is commonly treated with endocrine therapy (ET); however, over time, cancer cells can develop endocrine resistance. This review aims to document combination therapy and sequential therapy in the use of endocrine agents and targeted agents, by conducting two systematic searches using four databases: Cochrane Library, MEDLINE, EMBASE and Web of Science. A total of 26 studies that covered combination therapy were obtained and included for the review. Fourteen were phase III documenting combinations of mechanistic target of rapamycin (mTOR), phosphoinositide-3-kinase (PI3K), vascular endothelial growth factor receptor, human epidermal growth factor receptor 2 and cyclin-dependent kinase 4/6 (CDK4/6) inhibitors. The remaining studies were of phase II nature that reported combinations involving inhibitors in mTOR, endothelial growth factor receptor, CDK4/6 and TKI. Interesting findings in inhibitor combinations involving CDK4/6, mTOR and PI3K suggest clinical activity that can overcome endocrine resistance. On the other hand, there were 0 studies that covered sequential therapy. Overall findings showed that combination therapy improved treatment efficacy over monotherapy in postmenopausal patients with hormone receptor-positive advanced breast cancer. Inevitably, the benefits are accompanied with increased toxicity. To optimise ET, further research into combinations and effective patient selection will need to be defined. Additionally, this review warrants future studies to explore sequential therapy.

Comparative effectiveness of early-line nab-paclitaxel vs. paclitaxel in patients with metastatic breast cancer: a US community-based real-world analysis

Background

Real-world analyses of treatments for patients with metastatic breast cancer are limited. We evaluated the comparative effectiveness of nab-paclitaxel vs. paclitaxel in patients with metastatic breast cancer using data from an electronic medical record database from community practices across the USA.

Methods

We performed a retrospective cohort study using fully de-identified data from an independent US electronic medical record platform of patients with metastatic breast cancer initiating single-agent nab-paclitaxel or paclitaxel as a first- or second-line treatment from December 1, 2010 to October 6, 2014. The clinical efficacy objectives were time to treatment discontinuation (TTD) and time to next treatment (TTNT). Subgroup analyses were performed in patients with 2 types of metastatic breast cancer as follows: 1) hormone receptor-positive and human epidermal growth factor receptor 2 negative, and 2) triple-negative disease.

Results

This analysis included 925 patients. Patients receiving nab-paclitaxel vs. paclitaxel had significantly longer TTD (median 4.2 vs. 2.8 months, P<0.0001) and TTNT (median 6.0 vs. 4.2 months, P<0.0001); similar outcomes were observed for patients with hormone receptor-positive/human epidermal growth factor receptor 2 negative disease. Compared with paclitaxel, nab-paclitaxel was associated with significantly longer TTD in patients with triple-negative disease. nab-Paclitaxel was associated with significantly less all-grade neuropathy, anemia, pain, and diarrhea than paclitaxel. Antiemetic and antihistamine use were significantly less frequent with nab-paclitaxel vs. paclitaxel, whereas use of granulocyte colony-stimulating factor, hydrating agents, and bone-directed therapy to decrease skeletal-related events were more frequent.

Conclusion

nab-Paclitaxel demonstrated improved clinical effectiveness compared with paclitaxel when examining TTD and TTNT in patients with metastatic breast cancer in a real-world setting.

Efficacy of management strategies for aromatase inhibitor-induced arthralgia in breast cancer patients: a systematic review

Aromatase inhibitors are the gold standard in the treatment of hormone receptor-positive breast cancer, but lead to an arthralgia syndrome which is implicated in 13-22% of noncompliance. This is the first systematic review of the efficacy of existing management strategies for this side effect. Eligible studies were retrieved from computer searches of Medline, Cochrane and Embase and the significant intervention groups were identified. The risk of bias of selected studies was evaluated and the relevant data items were extracted, summarized and analyzed. A total of 21 studies were discussed in this review representing 12 different interventions. While several trials had positive findings, the major methodological limitations of the studies meant that no definitive evidence could be found supporting any of the interventions. Future trials are needed which address the methodological problems identified in this review. Exercise holds promise for future research based on its proven benefit in breast cancer.

The safety of palbociclib for the treatment of advanced breast cancer

INTRODUCTION

Despite improvements in the diagnosis and management of early stage breast cancer, about one third of the patients still progress to metastatic disease. Most of the patients with metastatic breast cancer have a hormone receptor positive and human epidermal growth factor receptor 2 negative subtype with a median survival of more than 3 years. For these patients, endocrine therapy with its favorable toxicity profile is the current standard of care. However, patients with metastatic breast cancer have an incurable disease. Therefore, not only efficacy but also quality of life are key when selecting a therapy regimen. Areas covered: This paper aims to discuss the efficacy and toxicity profile of the new endocrine-based therapy option palbociclib together with endocrine treatment. Expert opinion: The addition of targeted agents like palbociclib can overcome intrinsic or acquired resistance to endocrine therapy and substantially prolong progression free survival. The combination of palbociclib plus endocrine therapy is associated with a tolerable and well manageable toxicity profile as well as maintenance of quality of life. Thus, addition of palbociclib to endocrine therapy offers a new and important treatment option for hormone receptor positive metastatic breast cancer.

Efficacy and safety of palbociclib in heavily pretreated patients with HR+/HER2- metastatic breast cancer

AIM

CDK4/6 inhibitors in the first and second treatment line in patients with HR+/HER2- metastatic breast cancer (mBC) in combination with hormonal therapy improve progression-free survival. Role of CDK4/6 inhibitors in further treatment lines remains unclear.

METHODS

Retrospective analysis of 24 HR+/HER2- heavily pretreated mBC patients is presented.

RESULTS

A total of 58.3% patients achieved stable disease. No objective response was observed. Median progression-free survival was 4.8 months; median overall survival was 11 months. Treatment was well tolerated.

CONCLUSION

Favorable toxicity profile and efficacy of palbociclib/aromatase inhibitors combination in heavily pretreated luminal mBC patients in this study emphasize the need for further investigation of such drugs in this population.

A randomized phase II study of aromatase inhibitors plus metformin in pre-treated postmenopausal patients with hormone receptor positive metastatic breast cancer

Background

Everolimus significantly improves progression-free survival (PFS) and has been approved to use in aromatase inhibitor pretreated patients with hormone receptor positive advanced breast cancer. Metformin has been shown to inhibit mTOR pathway, with more favorable safety profile, leading to this hypothesis-generating trial to assess whether metformin enhances the efficacy of aromatase inhibitors.

Methods

60 postmenopausal women with hormone receptor positive locally advanced or metastatic breast cancer were randomly assigned 1:1 to aromatase inhibitor (exemestane 25mg/d or letrozole 2.5mg/d depending on the most recent treatment) plus metformin (0.5g bid, orally) or placebo. The primary endpoint was PFS, and secondary endpoints were objective response rate, clinical benefit rate, overall survival and safety.

Results

Median PFS was 4.7 months in the combination group and 6.0 months in the control group (hazard ratio, 1.2; 95% confidence interval [CI], 0.7 to 2.1; P =0.48). ORR was 6.7% in the combination group and 0% in the control group (odds ratio for ORR not available; P =0.99), and CBR was 33.3% and 50.0%, respectively (OR for CBR 0.5; 95% CI, 0.2 to 1.4; P=0.15). No significant difference in overall survival was observed between the combination and control groups (median OS, 30.9 vs. 32.4 months; P = 0.81). Subgroup analyses didn't find any specific population favoring the combination treatment. No substantial difference in incidence or severity of adverse events was seen between the two treatment groups.

Conclusion

This randomized phase II clinical trial failed to show an improved efficacy with the addition of metformin to endocrine therapy, although with excellent tolerability.

Ribociclib for the treatment of advanced hormone receptor-positive, HER2-negative breast cancer

CDK4/6 inhibitors are a promising new class of drugs for hormone-receptor-positive breast cancer and have been shown to overcome and delay hormone resistance in advanced breast cancer. Ribociclib, a selective oral inhibitor of CDK4/6, was approved by the US FDA for first-line treatment of hormone-receptor-positive/HER2-negative metastatic breast cancer. This review summarizes the clinical evidence available for ribociclib, from preclinical data to the pivotal studies, with a special focus on toxicity and its management. In addition, this article reviews potential new combinations under study, as well as ongoing clinical trials both in the metastatic and early setting. Finally, this review compares ribociclib activity and toxicity with those of the drugs of the same class (palbociclib and abemaciclib).

Outcomes in patients with early-stage breast cancer who underwent a 21-gene expression assay

BACKGROUND

Invasive disease-free survival (IDFS) rates are excellent in patients with breast cancer (BC) with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-), axillary lymph node-negative (LN-) tumors with a 21-gene expression assay recurrence score (RS) of 0 to 10. However, to the authors' knowledge, the outcomes among patients with an RS of 11 to 25 who are treated with endocrine therapy alone are unknown.

METHODS

In this retrospective single-institution study, the authors described the characteristics of patients with HR+, HER2-, LN- BC who underwent a 21-gene expression assay. In addition, among those individuals diagnosed between 2005 and 2011, we measured IDFS, recurrence-free survival, distant recurrence-free survival, and overall survival rates, focusing on patients with an RS of 11 to 25 by receipt of chemotherapy. The Kaplan-Meier method was used to estimate survival rates and multivariable Cox proportional hazards models were used to calculate hazard ratios and 95% confidence intervals (95% CIs).

RESULTS

Among 1424 patients, the RS distribution was 0 to 10 in 297 patients (21%), 11 to 25 in 894 patients (63%), and >25 in 233 patients (16%); of these, 1.7%, 15%, and 73.4% of patients, respectively, received chemotherapy. With a median follow-up of 58 months, those patients with an RS of 11 to 25 had an IDFS rate at 5 years of 92.6% (95% CI, 89.6%-94.7%), which was comparable between those who received chemotherapy and those who did not. The hazard ratios of the effect of chemotherapy were 1.64 for IDFS (95% CI, 0.73-3.71), 1.46 for recurrence-free survival (95% CI, 0.41-5.23), 1.25 for distant recurrence-free survival (95% CI, 0.32-4.92), and 2.19 for overall survival (95% CI, 0.44-11.0).

CONCLUSIONS

The results of the current study demonstrate similar outcomes with or without chemotherapy in patients with HR+, HER2-, LN- BC who have an RS of 11 to 25, but a benefit from chemotherapy in this group cannot be ruled out. Cancer 2017;123:2422-31. © 2017 American Cancer Society.

Hormone receptor positive, HER2 negative metastatic breast cancer: A systematic review of the current treatment landscape

Endocrine therapy for the treatment of hormone receptor positive, HER2 negative, metastatic breast cancer is continually evolving. We systematically reviewed phase 2 and 3 randomized controlled trials (RCTs) of agents used in this setting to assess the effectiveness and safety of these agents for postmenopausal women. Across the 32 studies in more than 10,000 patients, the greatest improvement in progression-free survival (PFS) was seen with the addition of a cyclin-dependent kinase (CDK)4/6 inhibitor to standard endocrine therapy. Treatment with a mammalian target of rapamycin (mTOR) inhibitor, phosphoinositol-3-kinase (Pi3K) inhibitor, vascular endothelial growth factor (VEGF) inhibitor and with a selective estrogen receptor degrader (SERD) also showed benefit in PFS for selected trials. Overall survival (OS) improved with the use of mTOR inhibitors and a SERD; however, studies were not powered for an OS endpoint. Encouraging results from early studies of histone deacetylase (HDAC) and B-cell lymphoma (BCL2) inhibitors are yet to be confirmed in phase III clinical trials. Study discontinuation rates and toxicity-related deaths were highest with VEGF inhibitors in combination with endocrine therapy, limiting their use in hormone receptor positive breast cancer. CDK4/6 inhibitors and mTOR inhibitors appeared to have activity in both first and second line settings, but required additional monitoring for common toxicities. The activity of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors was limited to the first-line setting and treatment discontinuation rates were higher than with mTOR inhibitors and SERDs. Overall, PFS benefit appears to be greatest when agents acting on CDK4/6, mTOR and Pi3K pathways, and SERDs are added to standard endocrine therapy. If these early results persist in further studies, these data are likely to change the way we treat hormone receptor positive, HER2 negative metastatic breast cancer. In the follow-up article to this review, we will consider the potential future treatment options for these patients.

Costs and mortality of recurrent versus de novo hormone receptor-positive/HER2(-) metastatic breast cancer

AIM

To examine cost and mortality differences in postmenopausal women with HR(+)/HER2(-) advanced breast cancer.

METHODS

Using claims data (2007-2013), women with newly diagnosed (de novo) stage IV, or early- or late-recurring metastatic breast cancer were identified.

RESULTS

Compared with de novo (n = 121) and late-recurrent (n = 106), early-recurrent (n = 172) patients had significantly higher costs in total and for anticancer systemic agents. Adjusted per patient per month costs for early-recurrent patients were US$13,404, versus US$9955 (de novo) and US$9721 (late-recurrent; p = 0.02). Early-recurrent patients' risk of death was twice that of de novo patients (p = 0.02).

CONCLUSION

Compared with new diagnosis or late recurrence, early recurrence of HR+/HER2- metastatic breast cancer was associated with higher mortality and healthcare costs.

Hormone receptor positive, HER2 negative metastatic breast cancer: Future treatment landscape

Endocrine therapy is an established and effective treatment strategy for hormone receptor positive metastatic breast cancer. The clinical utility of endocrine therapy is lost over time due to evolving changes in tumor biology and the development of endocrine resistance. Many agents targeting the intracellular signaling pathways associated with endocrine resistance are in development. Encouraging early results have been seen for agents which directly target the estrogen receptor (ER), inhibitors of co-signaling pathways, inhibitors of ER chaperones, ER antagonists able to inhibit mutated or otherwise activated ERs, and modulators of histone acetylation restoring synthesis of ER signaling components. Following our systematic review of treatments with established benefits in this supplement, we review some of the more promising new strategies for overcoming endocrine resistance, looking at the impact on disease control and quality of life for women with hormone receptor positive, HER2 negative breast cancer. We also examine the biomarkers that may guide selection of the best therapy for the individual.

Treating Elderly Patients With Hormone Receptor-Positive Advanced Breast Cancer

As the overall population ages, the proportion of elderly patients (aged ≥65 years) with breast cancer also increases. Studies have shown that elderly patients with hormone receptor–positive breast cancer can derive as much benefit from treatment as do younger patients, yet they remain underrepresented in clinical trials and are often undertreated in clinical practice. Treatment decisions for older patients should not be based solely on chronologic age; a patient’s physiologic functioning and comorbidities must also be taken into consideration. For recurrent or metastatic disease, systemic treatment with endocrine therapies or chemotherapy may prolong a patient’s life and alleviate troublesome symptoms. Resistance to therapy remains a problem in the advanced breast cancer setting, with most patients eventually becoming resistant to additional treatment. New combination regimens that target multiple pathways, such as everolimus plus exemestane, have shown efficacy in elderly patients previously resistant to endocrine therapies, and future research may need to focus on such combinations in order to improve outcomes in this patient group. A number of investigational agents are in clinical development, although few studies identify their effects in the elderly patient population. Optimizing effective yet tolerable therapeutic regimens for elderly patients could improve their outcomes while ensuring that the goals of improved survival and quality of life are considered.

The sequential use of endocrine treatment for advanced breast cancer: where are we?

BACKGROUND

Hormone receptor-positive advanced breast cancer is an increasing health burden. Although endocrine therapies are recognised as the most beneficial treatments for patients with hormone receptor-positive advanced breast cancer, the optimal sequence of these agents is currently undetermined.

METHODS

We reviewed the available data on randomised controlled trials (RCTs) of endocrine therapies in this treatment setting with particular focus on RCTs reported over the last 15 years that were designed based on power calculations on primary end points.

RESULTS

In this paper, data are reviewed in postmenopausal patients for the use of tamoxifen, aromatase inhibitors and fulvestrant. We also consider the available data on endocrine crossover studies and endocrine therapy in combination with chemotherapy or growth factor therapies. Treatment options for premenopausal patients and those with estrogen receptor-/human epidermal growth factor receptor 2-positive tumours are also evaluated.

CONCLUSION

We present the level of evidence available for each endocrine agent based on its efficacy in advanced breast cancer and a diagram of possible treatment pathways.

Economic evaluation of fulvestrant as an extra step in the treatment sequence for ER-positive advanced breast cancer

Drug therapies for advanced breast cancer in hormone-receptor-positive disease include both hormonal and chemotherapies. Current UK practice is to minimise toxicity by using sequential hormonal agents for as long as clinically appropriate. A Markov model was developed to investigate the cost effectiveness of different sequences of therapies, particularly exploring the effects of adding an additional hormonal agent, fulvestrant, to the treatment pathway. A systematic review was undertaken and a panel of seven UK oncologists validated assumptions used for treatment efficacy, treatment pathways and resources used. Fulvestrant was found to be a cost-effective treatment option when added to the treatment sequence as a second- or third-line hormonal therapy for advanced disease. For a cohort of 1000 patients, fulvestrant as a second-line hormone therapy provided an additional 47 life years and 41 quality-adjusted life years (QALYs), at an additional cost of pound 301 359. This equated to pound 6500 per life years gained and pound 7500 per QALY. When used as a third-line option, the fulvestrant arm was dominant providing an increase in health benefit of 27 QALYs for the whole cohort, at a mean overall cost reduction of pound 430 per patient. Sensitivity analyses showed these results to be robust, demonstrating that fulvestrant is an economically viable additional endocrine option in the United Kingdom for the treatment of hormone responsive advanced breast cancer.