Clinical considerations of the role of palbociclib in the management of advanced breast cancer patients with and without visceral metastases

Case series of metastatic breast cancer patients with visceral crisis treated with CDK4/6 inhibitors

There is an ongoing clinical dilemma of how best to treat patients who present themselves with visceral crisis. The time needed to undo the state of visceral crisis is the most relevant outcome for this patient group. We describe four patients treated with CDK4/6 inhibitor plus endocrine therapy for HR+/HER2- metastatic breast cancer who presented themselves with a visceral crisis. Two of them are male and three of them had synchronous metastatic breast cancer. Two patients had lymphangitis carcinomatosis of the lungs, one extensive disease of the eye and one of the liver. Time to first clinical response was observed within a few weeks in three patients. For one patient a switch to chemotherapy was needed. These cases show that treatment with CDK4/6 inhibitors can achieve a rapid response in patients experiencing visceral crisis. We conclude that chemotherapy is not the sole possibility in visceral crisis, and that CDK4/6 inhibitors can be considered as well.

Efficacy and safety of pyrotinib combined with albumin-bound paclitaxel as first-line treatment for HER2-positive metastatic breast cancer in patients previously treated with adjuvant and/or neoadjuvant trastuzumab therapy: The stage 1 results of a single-arm, phase 2 prospective clinical trial

OBJECTIVE

It has been observed that the prognosis of patients with HER2-positive metastatic breast cancer has improved significantly with HER2-targeted agents. However, there is still a lack of evidence regarding first-line anti-HER2 treatment options for patients who have received adjuvant and/or neoadjuvant trastuzumab for HER2-positive metastatic breast cancer. Besides, there are no reliable markers that can predict the efficacy of anti-HER2 treatment in these patients.

METHODS

Patients who have received adjuvant and/or neoadjuvant trastuzumab for HER2-positive metastatic breast cancer were enrolled. Pyrotinib plus albumin-bound paclitaxel were used as first-line treatment. The primary endpoint was the objective response rate (ORR). The safety profile was also assessed. In order to explore predictive biomarkers using Olink technology, blood samples were collected dynamically.

RESULTS

From December 2019 to August 2023, the first stage of the study involved 27 eligible patients. It has not yet reached the median PFS despite the median follow-up being 17.8 months. Efficacy evaluation showed that the ORR was 92.6%, and the DCR was 100%. Adverse events of grade 3 or higher included diarrhoea (29.6%), leukopenia (11.1%), neutropenia (25.9%), oral mucositis (3.7%), and hand-foot syndrome (3.7%). Toll-like receptor 3 (TLR3) and Proto-oncogene tyrosine-protein kinase receptor (RET) were proteins with significant relevance to PFS in these patients.

CONCLUSIONS

This study demonstrates that pyrotinib plus albumin-bound paclitaxel as a first-line treatment regimen shows good efficacy and manageable safety for patients who have received adjuvant and/or neoadjuvant trastuzumab for HER2-positive metastatic breast cancer. Besides, a significant association was identified between the expression levels of TLR3 and RET and the PFS in patients.

Recent progress of CDK4/6 inhibitors' current practice in breast cancer

Dysregulated cellular proliferation represents a hallmark feature across all cancers. Aberrant activation of the cyclin-dependent kinase 4 and 6 (CDK4/6) pathway, independent of mitogenic signaling, engenders uncontrolled breast cancer cell proliferation. Consequently, the advent of CDK4/6 inhibition has constituted a pivotal milestone in the realm of targeted breast cancer therapy. The combination of CDK4/6 inhibitors (CDK4/6i) with endocrine therapy (ET) has emerged as the foremost therapeutic modality for patients afflicted with hormone receptor-positive (HR + )/HER2-negative (HER2-) advanced breast cancer. At present, the Food and Drug Administration (FDA) has sanctioned various CDK4/6i for employment as the primary treatment regimen in HR + /HER2- breast cancer. This therapeutic approach has demonstrated a substantial extension of progression-free survival (PFS), often amounting to several months, when administered alongside endocrine therapy. Within this comprehensive review, we systematically evaluate the utilization strategies of CDK4/6i across various subpopulations of breast cancer and explore potential therapeutic avenues following disease progression during application of CDK4/6i therapy.

CDK4/6 inhibitors in lung cancer: current practice and future directions

Lung cancer is the leading cause of cancer-related deaths worldwide, and ∼85% of lung cancers are classified as nonsmall cell lung cancer (NSCLC). These malignancies can proliferate indefinitely, in part due to dysregulation of the cell cycle and the resulting abnormal cell growth. The specific activation of cyclin-dependent kinases 4 and 6 (CDK4/6) is closely linked to tumour proliferation. Approximately 80% of human tumours exhibit abnormalities in the cyclin D-CDK4/6-INK4-RB pathway. Specifically, CDK4/6 inhibitors either as monotherapy or combination therapy have been investigated in pre-clinical and clinical studies for the treatment of NSCLC, and promising results have been achieved. This review article focuses on research regarding the use of CDK4/6 inhibitors in NSCLC, including the characteristics and mechanisms of action of approved drugs and progress of pre-clinical and clinical research.

Estrogen receptor positive breast cancer: contemporary nuances to sequencing therapy

The treatment landscape of hormone receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer has evolved dramatically in recent years. While the combination of endocrine therapy and a cyclin-dependent kinase 4/6 inhibitor is accepted as standard first-line treatment in most settings without visceral crisis, newer therapies have challenged traditional treatment models where cytotoxic chemotherapy was previously felt to be the only second-line option at time of progression. The incorporation of next-generation sequencing has led to the identification of molecular targets for therapeutic agents, including phosphatidylinositol 3-kinase and ESR1, though similar pathways can be targeted even in the absence of a mutation, such as with use of inhibitors of mammalian target of rapamycin. Current data also supports the use of cyclin-dependent kinase inhibitors beyond progression, even prior to the patient's first introduction to chemotherapy. The abundance of therapeutic options not only delay time to cytotoxic chemotherapy and antibody-drug conjugate initiation, but has resulted in improvement in breast cancer survivorship. Many unanswered questions remain, however, as to the most efficacious way to sequence these novel agents. To assist in this decision-making, we will review the existing data on systemic therapy and propose a treatment paradigm.

Matching-adjusted indirect comparison of PFS and OS comparing ribociclib plus letrozole versus palbociclib plus letrozole as first-line treatment of HR+/HER2- advanced breast cancer

Background

Current standard-of-care first-line treatment of patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC) is cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) + endocrine therapy. In the MONALEESA-2 trial, first-line ribociclib + letrozole demonstrated statistically significant overall survival (OS) benefit versus placebo + letrozole in postmenopausal patients with HR+/HER2- ABC. In the PALOMA-2 trial, first-line palbociclib + letrozole did not show OS benefit versus placebo + letrozole in a similar patient population. Understanding OS outcomes in the respective trials is critical for treatment decisions; however, there are no head-to-head clinical trial data comparing ribociclib and palbociclib.

Objectives

To conduct a matching-adjusted indirect comparison (MAIC) to compare progression-free survival (PFS) and OS of first-line ribociclib + letrozole versus palbociclib + letrozole in postmenopausal patients with HR+/HER2- ABC.

Design

Letrozole-anchored MAIC using individual patient data from MONALEESA-2 and published summary data from PALOMA-2.

Methods

Using individual data, patients from MONALEESA-2 who matched inclusion criteria from PALOMA-2 were selected, and weighting was conducted to ensure baseline characteristics were similar to those in published aggregated data from PALOMA-2. The Bucher method was used to generate corresponding hazard ratios (HRs).

Results

The final effective sample size compared n = 150 (ribociclib) and n = 112 (placebo) MONALEESA-2 patients with n = 444 (palbociclib) and n = 222 (placebo) PALOMA-2 patients. After matching and weighting, patient characteristics were well balanced. MAIC analysis showed a numerical PFS benefit [HR, 0.80; 95% confidence interval (CI), 0.58-1.11; p = 0.187] and significant OS benefit (HR, 0.68; 95% CI, 0.48-0.96; p = 0.031) with ribociclib + letrozole versus palbociclib + letrozole.

Conclusion

Results of this cross-trial MAIC analysis showed a numerical PFS benefit and significantly greater OS benefit with first-line ribociclib + letrozole versus palbociclib + letrozole. These results support letrozole + ribociclib as the preferred first-line CDK4/6i for postmenopausal patients with HR+/HER2- ABC.

Trial registration

NCT01958021; https://www.clinicaltrials.gov/study/NCT01958021 (MONALEESA-2) and NCT01740427; https://clinicaltrials.gov/study/NCT01740427 (PALOMA-2).

Reporting of older subgroups in registration breast cancer trials 2012-2021

INTRODUCTION

Adequate reporting of data specific to older populations enrolled to breast cancer trials is critical, given the high incidence of the disease among this demographic. This study aimed to examine the completeness of reporting of older subgroups among patients recruited to registration clinical trials investigating systemic treatments for breast cancer.

METHODS

Clinical trials leading to a US food and drug administration (FDA) approval in breast cancer between 2012 and 2021 were included. Primary study reports and and all available secondary publications were systematically and objectively assessed with regard to the availability of data regarding efficacy, baseline characteristics, safety, and health-related quality of life (HRQOL) outcomes among older subgroups.

RESULTS

27 trials and 216 publications were assessed. 20.3% of patients were aged ≥65. 70.0% of patients had an eastern cooperative oncology group (ECOG) performance status of 0. Although complete reporting of primary endpoints was adequate (72.7%), most protocol-defined primary endpoints were surrogate endpoints (84.8%). Overall survival data among older populations was unavailable in 50.0% of studies. Reporting was poor for secondary efficacy endpoints (81.8% unreported), baseline characteristics (70.4% unreported), toxicity (55.6% unreported), and health-related quality of life outcomes (87.5% unreported).

CONCLUSION

The findings underline significant deficits in the reporting of age-specific data in breast cancer registration trials. The underreporting of key efficacy, safety, and HRQOL outcomes highlights the need for mandatory reporting standards and a dedicated emphasis on older populations' priorities and needs in the reporting of registration clinical trials.

CDK4/6 inhibitors versus weekly paclitaxel for treatment of ER+/HER2- advanced breast cancer with impending or established visceral crisis

PURPOSE

ER+/HER2- advanced breast cancer (ABC) with visceral crisis (VC) or impending VC (IVC) is commonly treated with chemotherapy instead of CDK4/6 inhibitors (CDK4/6i). However, there is little evidence to confirm which treatment is superior. This study compared outcomes of patients with ER+/HER2- ABC and IVC/VC treated with CDK4/6i or weekly paclitaxel.

METHODS

Patients with ER+/HER2- ABC receiving first line treatment at a large tertiary UK cancer centre from 1-Mar-2017 to 30-Jun-2021 were retrospectively identified. Hospital records were screened for IVC/VC affecting the liver, lungs/mediastinum, gastrointestinal tract and/or bone marrow. Baseline demographics, clinical data and survival outcomes were recorded up to 30-Jul-2022.

RESULTS

27/396 (6.8%) patients with ABC who received CDK4/6i and 32/86 (37.2%) who received paclitaxel had IVC/VC. Median time to treatment failure (TTF), progression-free survival (PFS) and overall survival (OS) were significantly longer in the CDK4/6i compared to paclitaxel cohort: TTF 17.3 vs. 3.5 months (HR 0.33, 95%CI 0.17-0.61, p = 0.0002), PFS 17.8 vs. 4.5 months (HR 0.38, 95%CI 0.21-0.67, p = 0.002), OS 24.6 vs. 6.7 months (HR 0.37, 95%CI 0.20-0.68, p = 0.002). The median time to first improvement in IVC/VC was similar in patients receiving CDK4/6i compared to paclitaxel (3.9 vs. 3.6 weeks, p = 0.773). Disease control at 4 months was not significantly different in the CDK4/6i and paclitaxel cohorts (77.8% vs. 59.4%, p = 0.168). In multivariate analysis, treatment with CDK4/6i was independently associated with a longer PFS compared to paclitaxel (HR 0.31, 95%CI 0.12-0.78, p = 0.015).

CONCLUSION

In this retrospective study, patients with ER+/HER2- ABC and IVC/VC treated with CDK4/6i had a significantly better survival compared to those treated with weekly paclitaxel. Further prospective studies that minimise possible selection bias are recommended.

A real-world study of the first use of palbociclib for the treatment of advanced breast cancer within the UK National Health Service as part of the novel Ibrance® Patient Program

BACKGROUND

The Ibrance® Patient Program was established to provide access to palbociclib for UK National Health Service (NHS) patients with metastatic breast cancer (MBC), pending a funding decision.

METHODS

Non-interventional cohort study involving a retrospective medical record review of patients commenced on palbociclib between April and December 2017 at eight UK centres. Primary outcomes included clinicopathological characteristics, treatment patterns, clinical outcomes and selected adverse events.

RESULTS

Overall, 191 patients were identified, median age of 57.0 years (range 24.3-90.9); 30% were diagnosed with de novo MBC; 72% received first-line and 10% as ≥ second-line treatment. Median progression-free survival (95% CI) was 22.8 months (16.5-not reached [NR]) in first-line; NR in patients with de novo MBC; 7.8 months (6.8-NR) in ≥ second-line (median follow-up: 24 months). Median overall survival (OS) was NR in the overall cohort; OS rate (95% CI) at 24 months was 74.2% (67.1-81.9%) in first-line; 82.1% (72.6-92.8%) in patients with de novo MBC; 55.0% (37.0-81.8%) in ≥ second-line. Forty-seven per cent of patients developed grade 3-4 neutropenia; 3% febrile neutropenia.

CONCLUSION

This study supports the effectiveness of palbociclib and demonstrates the benefit to patients of early access schemes that bridge the gap between regulatory approval and NHS funding for new medicines.

CLINICAL TRIAL REGISTRATION

Clinical trial: ClinicalTrial.gov:NCT03921866.

Risk factors and survival prediction of young breast cancer patients with liver metastases: a population-based study

Background

The risk and prognosis of young breast cancer (YBC) with liver metastases (YBCLM) remain unclear. Thus, this study aimed to determine the risk and prognostic factors in these patients and construct predictive nomogram models.

Methods

This population-based retrospective study was conducted using data of YBCLM patients from the Surveillance, Epidemiology, and End Results database between 2010 and 2019. Multivariate logistic and Cox regression analyses were used to identify independent risk and prognostic factors, which were used to construct the diagnostic and prognostic nomograms. The concordance index (C-index), calibration plot, receiver operating characteristic (ROC) curve, and decision curve analysis (DCA) were used to assess the performances of the established nomogram models. Propensity score matching (PSM) analysis was used to balance the baseline characteristics between the YBCLM patients and non-young patients with BCLM when comparing overall survival (OS) and cancer-specific survival (CSS).

Results

A total of 18,275 YBC were identified, of whom 400 had LM. T stage, N stage, molecular subtypes, and bone, lung, and brain metastases were independent risk factors for LM developing in YBC. The established diagnostic nomogram showed that bone metastases contributed the most risk of LM developing, with a C-index of 0.895 (95% confidence interval 0.877-0.913) for this nomogram model. YBCLM had better survival than non-young patients with BCLM in unmatched and matched cohorts after propensity score matching analysis. The multivariate Cox analysis demonstrated that molecular subtypes, surgery and bone, lung, and brain metastases were independently associated with OS and CSS, chemotherapy was an independent prognostic factor for OS, and marital status and T stage were independent prognostic factors for CSS. The C-indices for the OS- and CSS-specific nomograms were 0.728 (0.69-0.766) and 0.74 (0.696-0.778), respectively. The ROC analysis indicated that these models had excellent discriminatory power. The calibration curve also showed that the observed results were consistent with the predicted results. DCA showed that the developed nomogram models would be effective in clinical practice.

Conclusion

The present study determined the risk and prognostic factors of YBCLM and further developed nomograms that can be used to effectively identify high-risk patients and predict survival outcomes.

Abemaciclib, Palbociclib, and Ribociclib in Real-World Data: A Direct Comparison of First-Line Treatment for Endocrine-Receptor-Positive Metastatic Breast Cancer

By the end of 2020, there were more than 8 million women alive who had received a breast cancer diagnosis in the previous 5 years, making it the most prevalent neoplasia in the world. About 70% of breast-cancer cases present positivity for estrogen and/or progesterone receptors and a lack of HER-2 overexpression. Endocrine therapy has traditionally been the standard of care for ER-positive and HER-2-negative metastatic breast cancer. In the last 8 years, the advent of CDK4/6 inhibitors has shown that adding them to endocrine therapy doubles PFS. As a result, this combination has become the gold standard in this setting. Three CDK4/6 inhibitors have been approved by the EMA and the FDA: abemaciclib, palbociclib, and ribociclib. They all have the same indications, and it is at each physician's discretion to choose one or the other. The aim of our study was to perform a comparative efficacy analysis of the three CDK4/6i using real-world data. We selected patients diagnosed with endocrine-receptor-positive and HER2-negative breast cancer who were treated with all three CDK4/6i as first-line therapy at a reference center. After 42 months of retrospective follow up, abemaciclib was associated with a significant benefit in terms of progression-free survival in endocrine-resistant patients and in the population without visceral involvement. In our real-world cohort, we found no other statistically significant differences among the three CDK4/6 inhibitors.

How I treat endocrine-dependent metastatic breast cancer

Estrogen receptor-positive (ER+)/HER2-negative (HER2-), the so-called luminal-type breast cancer, is the most frequent subset, accounting for around 70% of all breast cancer cases. Endocrine therapy (ET) combined with cyclin-dependent kinases (CDK) 4/6 inhibitors is the standard first option in the management of advanced luminal breast cancer independently of disease extension. Classically, patients undergo multiple lines of ET ± targeted treatments until endocrine resistance occurs and palliative chemotherapy is proposed. Understanding endocrine resistance mechanisms and development of novel ET options is one of the main challenges in current clinical research. Another area of utmost interest is the improvement of post-endocrine therapeutic approaches. Among others, the development of antibody-drug conjugates (ADCs) is very promising, and some of these drugs will probably soon become a part of the therapeutic arsenal against this incurable disease. This review paper provides an overview of currently available treatment options in ER+/HER2- metastatic breast cancer and extensively discusses new approaches in late clinical development.

Systematic review of the management of brain metastases from hormone receptor positive breast cancer

INTRODUCTION

Brain metastases are a common cause of morbidity and mortality in patients with breast cancer. Local central nervous system (CNS) directed therapies are usually the first line treatment for breast cancer brain metastases (BCBM), but those must be followed by systemic therapies to achieve long-term benefit. Systemic therapy for hormone receptor (HR⁺) breast cancer has evolved in the last 10 years, but their role when brain metastases occur is uncertain.

METHODS

We performed a systematic review of the literature focused on management of HR⁺ BCBM by searching Medline/PubMed, EBSCO, and Cochrane databases. The PRISMA guidelines were used for systematic review.

RESULTS

Out of 807 articles identified, 98 fulfilled the inclusion criteria in their relevance to the management of HR⁺ BCBM.

CONCLUSIONS

Similar to brain metastases from other neoplasms, local CNS directed therapies are the first line treatment for HR⁺ BCBM. Although the quality of evidence is low, after local therapies, our review supports the combination of targeted and endocrine therapies for both CNS and systemic management. Upon exhaustion of targeted/endocrine therapies, case series and retrospective reports suggest that certain chemotherapy agents are active against HR⁺ BCBM. Early phase clinical trials for HR⁺ BCBM are ongoing, but there is a need for prospective randomized trials to guide management and improve patients' outcome.

On-treatment derived neutrophil-to-lymphocyte ratio and survival with palbociclib and endocrine treatment: analysis of a multicenter retrospective cohort and the PALOMA-2/3 study with immune correlates

BACKGROUND

Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors have been established as a standard treatment for hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC); however, predictive biomarkers with translational relevance have not yet been elucidated.

METHODS

Data from postmenopausal women who received the CDK4/6 inhibitor palbociclib and letrozole for HR-positive, HER2-negative ABC from tertiary referral centers were analyzed (N = 221; exploratory cohort). Pre- and on-treatment neutrophil-to-lymphocyte ratio (NLR) and derived NLR (dNLR; neutrophil/[leukocyte-neutrophil]) were correlated with survival outcomes. Data from the PALOMA-2 (NCT01740427) and PALOMA-3 studies (NCT01942135) involving patients treated with endocrine treatment with or without palbociclib were also analyzed (validation cohort). Prospectively enrolled patients (N = 20) were subjected to immunophenotyping with circulating immune cells to explore the biological implications of immune cell dynamics.

RESULTS

In the exploratory cohort, palbociclib administration significantly reduced leukocyte, neutrophil, and lymphocyte counts on day 1 of cycle 2. Although the baseline dNLR was not significantly associated with progression-free survival (PFS), higher on-treatment dNLRs were associated with worse PFS (hazard ratio = 3.337, P < 0.001). In the PALOMA-2 validation cohort, higher on-treatment dNLRs were associated with inferior PFS in patients treated with palbociclib and letrozole (hazard ratio = 1.498, P = 0.009), and reduction in the dNLR after treatment was predictive of a survival benefit (hazard ratio = 1.555, P = 0.026). On-treatment dNLRs were also predictive of PFS following palbociclib and fulvestrant treatment in the PALOMA-3 validation cohort. Using flow cytometry analysis, we found that the CDK4/6 inhibitor prevented T cell exhaustion and diminished myeloid-derived suppressor cell frequency.

CONCLUSIONS

On-treatment dNLR significantly predicted PFS in patients with HR-positive, HER2-negative ABC receiving palbociclib and endocrine treatment. Additionally, we observed putative systemic immune responses elicited by palbociclib, suggesting immunologic changes upon CDK4/6 inhibitor treatment.

Symptomatic bone marrow metastases in breast cancer: A retrospective cohort study

Objective

Breast cancer symptomatic bone marrow metastasis (BMM) is rare and has a poor prognosis. Chemotherapy is usually the primary treatment, but it has limited efficacy, resulting in dose reduction and a decrease in quality of life due to the adverse effects of the agent. Other than chemotherapy, there are no other treatment studies for BMM. This study aimed to explore the clinicopathological characteristics of BMM patients with breast cancer, the prognosis using different treatment modalities, and the risk factors that affect the prognosis.

Methods

This retrospective study included patients diagnosed with breast cancer BMM from January 2018 to January 2022 in the Cancer Center of the First Hospital of Jilin University. The analysis focused on the characteristics of the patients, the treatment regimen, and the prognosis.

Results

Of 733 patients with advanced breast cancer, 33 patients were identified with BMM. All patients showed a hemoglobin decrease, and 25 (75.75%) presented with a fever of unknown origin. As for the metastasis breast cancer subtype, 25 (75.75%) were hormone receptor (HR) positive/human epidermal growth factor receptor 2 (HER2) negative, three (9.09%) had HER2 overexpression, and five (15.15%) were triple negative. The BMM patients had a median progression-free survival (PFS) of 7 months (1-21 months) and a median overall survival (OS) of 18 months (2-108 months). Among 25 HR⁺/HER2^- BMM patients treated with different modalities, the median OS of the endocrine therapy (ET) group was 23 months, compared with 5 months in the chemotherapy group. Cox proportional hazards models suggested that higher Eastern Cooperative Oncology Group (ECOG) scores and old age were associated with shorter survival.

Conclusion

When breast cancer patients present with anemia and fever of unknown origin, BMM should be considered. For HR⁺/HER2^- patients with good physical status and can receive active treatment, CDK4/6 inhibitors combined with ET can be used to control disease progression, improve quality of life, and prolong survival.

Effect of palbociclib plus endocrine therapy on time to chemotherapy across subgroups of patients with hormone receptor‒positive/human epidermal growth factor receptor 2‒negative advanced breast cancer: Post hoc analyses from PALOMA-2 and PALOMA-3

BACKGROUND

Previous analyses from the PALOMA-2 and PALOMA-3 studies showed that palbociclib (PAL) plus endocrine therapy (ET) prolongs time to first subsequent chemotherapy (TTC) versus placebo (PBO) plus ET in the overall population of patients with hormone receptor‒positive/human epidermal growth factor receptor 2‒negative (HR+/HER2-) advanced breast cancer (ABC). Here, we evaluated TTC in relevant patient subgroups.

METHODS

These post hoc analyses evaluated TTC by subgroup using data from 2 randomized, phase 3 studies of women with HR+/HER2- ABC. In PALOMA-2, postmenopausal patients previously untreated for ABC were randomized 2:1 to receive PAL (125 mg/day, 3/1-week schedule) plus letrozole (LET; 2.5 mg/day; n = 444) or PBO plus LET (n = 222). In PALOMA-3, premenopausal or postmenopausal patients whose disease had progressed after prior ET were randomized 2:1 to receive PAL (125 mg/day, 3/1-week schedule) plus fulvestrant (FUL; 500 mg; n = 347) or PBO plus FUL (n = 174).

RESULTS

First subsequent chemotherapy was received by 35.5% and 56.2% in PALOMA-2 and PALOMA-3 after progression on palbociclib plus ET or placebo plus ET. Across all subgroups analyzed, the median progression-free survival (PFS) was longer in the PAL plus ET arm than the PBO plus ET arm. TTC was longer with PAL plus ET versus PBO plus ET across the same patient subgroups in both studies.

CONCLUSIONS

Across all subgroups, PAL plus ET versus PBO plus ET had longer median PFS and resulted in prolonged TTC in both the PALOMA-2 and PALOMA-3 studies. Pfizer Inc (NCT01740427, NCT01942135).

Different treatment regimens in breast cancer visceral crisis: A retrospective cohort study

Objective

Breast cancer visceral crisis (VC) is caused by excessive tumor burden leading to severe organ dysfunction with poor prognosis. Traditional chemotherapy reduces the quality of life of patients without significantly improving survival. The aim of this study was to investigate the clinical characteristics of patients with VC and the prognosis by using different treatment options.

Methods

According to the 5th European School of Oncology (ESO)–European Society for Medical Oncology (ESMO) international consensus guidelines for advanced breast cancer guidelines (ABC 5), patients who were treated in the First Hospital of Jilin University from 2018 to 2022 and diagnosed with breast cancer VC were retrospectively analyzed. The analysis focused on the characteristics of the patients, the treatment regimens, and prognosis.

Results

A total of 133 patients were included in this study. As for metastasis breast cancer subtype, 92 (69.18%) were hormone receptor (HR) positive, human epidermal growth factor receptor 2 (HER-2) negative, 20 (15.04%) had HER-2 overexpression, and 21 (15.78%) were triple negative. All patients had an mOS of 11.2 months (range, 1.1–107.8 months). In different types of VC, the median overall survival (mOS) of bone marrow metastasis (BMM) was 18.0 months (range, 2.0–107.8 months), that of diffuse liver metastasis (DLM) was 8.1 months (range, 1.3–30.2 months), and that of meningeal metastasis (MM) was 9.0 months (range, 1.2–53.8 months). In 92 HR+, Her-2− patients using different treatment regimens, mOS was 6.2 months (range, 1.2–29.8 months) in the chemotherapy group while it was 24.3 months (range, 3.1–107.8 months) in the endocrine therapy (ET) group. Multivariate Cox regression analysis suggested that Eastern Cooperative Oncology Group (ECOG) scores and type of VC were associated with survival.

Conclusion

Prognosis varied in different types of VC. Patients with BMM had the best prognosis, and DLM had the worst. As treatment options continue to progress, our retrospective study showed a significant prolongation of overall survival (OS) in patients with VC compared to previous studies.

Inositol monophosphatase 1 (IMPA1) promotes triple-negative breast cancer progression through regulating mTOR pathway and EMT process

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, which is characterized by high heterogeneity and metabolic dysregulation. Inositol monophosphatase 1(IMPA1) is critical for the metabolism of inositol, which has profound effects on gene expression and other biological processes. Here, we report for the first time that IMPA1 was upregulated in TNBC cell lines and tissues, and enhanced cell colony formation and proliferation in vitro and tumorigenicity in vivo. Additionally, IMPA1 promoted cell motility in vitro and metastatic lung colonization in vivo. Mechanistic investigations by transcriptome sequencing revealed that 4782 genes were differentially expressed between cells with IMPA1 knockdown and control cells. Among the differentially expressed genes after IMPA1 knockdown, five significantly altered genes were verified via qRT-PCR assays. Morerover, we found that the expression profile of those five targets as a gene set was significantly associated with IMPA1 status in TNBC cells. As this gene set was associated with mTOR pathway and epithelial-mesenchymal transition (EMT) process, we further confirmed that IMPA1 induced mTOR activity and EMT process, which at least in part contributed to IMPA1-induced TNBC progression. Collectively, our findings reveal a previously unrecognized role of IMPA1 in TNBC progression and identify IMPA1 as a potential target for TNBC therapy.

Clinicopathological Features Related to the Efficacy of CDK4/6 Inhibitor-Based Treatments in Metastatic Breast Cancer

Background:

Resistance to endocrine therapy has been a major obstacle in the management of hormone receptor (HR)-positive metastatic breast cancer (MBC). Meanwhile, a number of treatments are available to such patients, and physicians often encounter difficulties in choosing the most appropriate treatments for individual patients. The combination of CDK 4/6 inhibitors (CDKi) and endocrine therapy has now become a standard treatment for HR-positive and human epidermal growth factor receptor 2 (HER2)-negative MBC. However, no predictive markers for CDKi-based treatments have been established. Considering their side effects and the financial burden on patients, identifying such markers is crucial.

Methods:

Clinicopathological features of 107 patients with HR-positive HER2-negative MBC, who received CDKi-based treatments at our institution were retrospectively investigated. HR status in distant metastatic lesions and immunocompetent cells in peripheral blood were also studied.

Results:

Progression-free survival (PFS) was significantly shorter in patients whose primary tumour was high grade (P = 0.016) or high neutrophil-to-lymphocyte ratio (NLR) at baseline (P = 0.017). Meanwhile, there were no differences in other factors, such as expression levels of hormone receptors. Patients whose metastatic lesions were of low tumour grade or high Ki67 labelling index had longer PFS, and such trends were more obvious than primary lesions.

Conclusion:

Our data indicate that tumour grade in primary lesion and NLR are potential predictive factors for CDKi-based treatments. Moreover, pathological assessment of metastatic lesions might also be useful.

The efficacy and safety of palbociclib combined with endocrine therapy in patients with hormone receptor-positive HER2-negative advanced breast cancer: a multi-center retrospective analysis

To explore the efficacy and safety of palbociclib combined with endocrine therapy (ET) in advanced breast cancer (ABC). We conducted a retrospective study involving patients with hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-) ABC who received palbociclib combined with ET in the first- to third-line at three centers in China between January 2018 and October 2020. A total of 151 patients were included in this study. The median age of the patients at palbociclib initiation was 56 years (range 30-86 years) with a median follow-up of 10.9 months (range 2.0-41.2 months). Among these patients, 88 patients received palbociclib combined with ET as first-line therapy, and achieved a median progression-free survival (mPFS) of 19.8 months and an objective response rate (ORR) of 40.9%, meanwhile, in the first-line setting, 62 patients received palbociclib at an initial dose of 125 mg, achieving a mPFS of 20.9 months and an ORR of 46.8%. There were 39 and 24 patients who received palbociclib combined with ET as second- and third-line therapy, the mPFS were 10.0 months and 6.1 months, respectively. The most common and serious adverse events (AEs) were leukopenia and neutropenia. A total of 64 patients (42.4%) underwent palbociclib dose reduction due to AEs. Palbociclib combined with ET is an effective therapeutic regimen for HR+/HER2- ABC, particularly in the first-line setting with palbociclib initial dose of 125 mg, and AEs were manageable.

Quality-of-life methodology in hormone receptor-positive advanced breast cancer: Current tools and perspectives for the future

Health-related quality of life (HRQOL) is increasingly recognized as important when evaluating cancer treatments. The use, reporting, and analysis of patient-reported outcome measures (PROMs), however, are not standardized in clinical trials and are often poorly implemented in clinical practice. We report the results of a systematic literature review (PubMed search: January 1, 2000 to August 15, 2020) of PROM use, reporting, and analysis in phase 3 clinical trials of hormone receptor-positive (HR+) advanced breast cancer (ABC). Further inspection of cyclin-dependent kinase 4/6 (CDK4/6) inhibitor publications was performed to examine PROMs in the HR+/human epidermal growth factor receptor 2-negative setting. A total of 88 results were identified in the initial search; 32 were included in the final analysis. Among included studies, most (66%) had been published in the last 5 years (2015 to 2020). CDK4/6 inhibitors (38%) were the most common agents reported. No clear standard for PROM use, reporting, or analysis was found. The most common PROMs were European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30; 59%) and the Functional Assessment of Cancer Therapy-Breast (FACT-B; 34%). Important differences, among studies that reported them, ranged from 5 to 10 points for the EORTC QLQ-C30 and 8 points for the FACT-B total score. This review showed that a lack of clear consistency remains for PROM use, reporting, and analysis in phase 3 clinical trials of HR+ ABC. However, HRQOL is of high interest in the literature, including for CDK4/6 inhibitors.

Phase II trail of nab-paclitaxel in metastatic breast cancer patients with visceral metastases

Background

Visceral metastases account for 48–67% of metastatic breast cancer (MBC) patients and presage a worse overall survival. Previous study suggested potential effect of nab-paclitaxel on patients with visceral metastases subgroups. This phase II trial was conducted to explore the efficacy and safety of nab-paclitaxel in such a high-risk group of patients.

Methods

In this prospective, single-center, open-label, phase II study, MBC patients with visceral metastases (N = 80) received nab-paclitaxel (Abraxane, 125 mg/m2, D1, D8, D15 every 28 days).

Results

The median PFS was 5.1 months (95% CI: 4.2–6.0 months), with an ORR of 33.8% (95% CI 21.3–43.8%) and CBR of 66.2% (95% CI 56.3–75.0%). In univariate analysis, patients with premenopausal status had a trend of better treatment outcome. Multivariate analysis demonstrated non brain metastasis (adjusted HR 0.31, 95% CI 0.12–0.83, P = 0.019) and first line treatment (adjusted HR 0.37, 95% CI 0.17–0.81, P = 0.013) as independent predictors of longer PFS. The overall safety was acceptable with most common treatment-related, grade ≥ 3 toxicities of neutropenia (16.3%) and sensory neuropathy (3.7%).

Conclusions

This phase II trial documented satisfactory efficacy and safety of nab-paclitaxel in MBC patients with visceral metastases, providing evidence for relative clinical practice. Patients in first line therapy had better treatment outcome. For patients with premenopausal status or brain metastasis, further alternatives (for example, combined chemotherapy or targeting therapy) might be required. This study also demonstrated the efficacy and safety of 125 mg/m2 nab-paclitaxel among Asian patients.

Trial registration

This research is registered under clinicaltrials.gov (NCT 02687490, February 22, 2016).

Palbociclib as an early-line treatment for Japanese patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer: a review of clinical trial and real-world data

Breast cancer is the most common type of cancer among women worldwide and in Japan. The majority of breast cancers are hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2‒), and endocrine therapy is an effective therapy for this type of breast cancer. However, recent substantial advances have been made in the management of HR+/HER2‒ advanced breast cancer (ABC) with the advent of targeted therapies, such as cyclin-dependent kinase 4/6 (CDK4/6) inhibitors, resulting in significant improvements in survival outcomes versus endocrine therapy alone. To evaluate the optimal use of palbociclib, a CDK4/6 inhibitor, in HR+/HER2- ABC, this review summarizes clinical trial and real-world data for palbociclib. In addition, current biomarker studies in palbociclib clinical research are reviewed. In Japanese patients, palbociclib was shown to be effective with a manageable safety profile, although differences were observed in the frequency of adverse event and dosing parameters. Current evidence supporting palbociclib as a first-line treatment strategy for patients with HR+/HER2‒ ABC in Asia, and specifically japan, is also discussed.

Clinical Features and Serological Markers Risk Model Predicts Overall Survival in Patients Undergoing Breast Cancer and Bone Metastasis Surgeries

Background

Surgical therapy of breast cancer and bone metastasis can effectively improve the prognosis of breast cancer. However, after the first operation, the relationship between preoperative indicators and outcomes in patients who underwent metastatic bone surgery remained to be studied. Purpose 1. Recognize clinical and laboratory prognosis factors available to clinical doctors before the operation for bone metastatic breast cancer patients. 2. Develop a risk prediction model for 3-year postoperative survival in patients with breast cancer bone metastasis.

Methods

From 2014 to 2020, patients who suffered from breast cancer bone metastasis and received therapeutic procedures in our institution were included for analyses (n=145). For patients who underwent both breast cancer radical surgery and bone metastasis surgery, comprehensive datasets of the parameters of interest (clinical features, laboratory factors, and patient prognoses) were collected (n=69). We performed Multivariate Cox regression to identify factors that were associated with postoperative outcome. 3-year survival prediction model and nomograms were established by 100 bootstrapping. Its benefit was evaluated by calibration plot, C-index, and decision curve analysis. The Surveillance, Epidemiology, and End Results database was also used for external validation.

Results

Radiotherapy for primary cancer, pathological type of metastatic breast cancer, lymph node metastasis, elevated serum alkaline phosphatase, lactate dehydrogenase were associated with postoperative prognosis. Pathological types of metastatic breast cancer, multiple bone metastasis, organ metastases, and elevated serum lactate dehydrogenase were associated with 3-year survival. Then those significant variables and serum alkaline phosphatase counts were integrated to construct nomograms for 3-year survival. The C-statistic of the established predictive model was 0.83. The calibration plot presents a graphical representation of calibration. In the decision curve analysis, the benefits are higher than those of the extreme curve. The receiver operating characteristic of the external validation of the model was 0.82, indicating a favored fitting degree of the two models.

Conclusion

Our study suggests that several clinical features and serological markers can predict the overall survival among the patients who are about to receive bone metastasis surgery after breast cancer surgery. The model can guide the preoperative evaluation and clinical decision-making for patients. Level of evidence Level III, prognostic study.

Real-World Efficacy of Fulvestrant Monotherapy as the First Treatment or Maintenance Treatment in Patients with Metastatic Breast Cancer

Background

Fulvestrant 500 mg monotherapy is recommended as the first-line endocrine treatment in postmenopausal women with hormone receptor-positive metastatic breast cancer (MBC). It is also used in MBC maintenance treatment. However, few studies have compared the efficacy of fulvestrant during the initial treatment with that during maintenance treatment.

Patients and Methods

MBC patients who were treated with fulvestrant either as initial therapy for metastatic disease or after progression following one line of chemotherapy between January 2016 and December 2017 were identified from the database of the Affiliated Hospital of Qingdao University. The primary end point was progression-free survival (PFS).

Results

The study included 135 MBC patients who were treated with fulvestrant; 116 patients who received fulvestrant as first-line treatment were divided into 2 groups: the no-chemotherapy treatment (NCT) group received fulvestrant as initial therapy during disease progression, and the chemotherapy treatment (CT) group received fulvestrant as maintenance following disease stabilization or response to previous chemotherapy. The median PFS was 16 months in NCT patients and 8 months in the CT group. Patients who had a longer disease-free survival, no visceral metastasis and one metastasis site, benefited from fulvestrant as first-line treatment during disease progression. Patients with 2 or more metastasis sites benefited from chemotherapy as first-line treatment and fulvestrant as maintenance treatment.

Conclusions

Fulvestrant monotherapy showed good clinical activity and safety in patients with MBC who were treated upon disease progression and in those receiving maintenance therapy.

Mechanisms and Implications of CDK4/6 Inhibitors for the Treatment of NSCLC

Cyclin-dependent kinases (CDKs) are key regulators of cell cycle progression in malignant tumor cells and play an important role through complex molecular interactions. Dysregulation of CDK dependent pathways is often found in non-small cell lung cancer, which indicates its vulnerability and can be used in clinical benefit. CDK4/6 inhibitors can prevent tumor cells from entering the G approved 1 and S phases, which have been studied in a series of explorations and brought great clinical effect to patients and encouragement to both physicians and researchers, thereby showing potential as a new therapeutic agent. A series of preclinical and clinical studies have been carried out on CDK4/6 inhibitors in NSCLC, and have been achieved some results, which may become a new potential treatment in the future. This review focuses on the research progress on CDK4/6 inhibitors in NSCLC, particularly the mechanisms of action, drugs, clinical research progress, and future application.

Endocrine Treatment and Targeted Therapy for Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Metastatic Breast Cancer: ASCO Guideline Update

PURPOSE

To update recommendations of the ASCO systemic therapy for hormone receptor (HR)-positive metastatic breast cancer (MBC) guideline.

METHODS

An Expert Panel conducted a systematic review to identify new, potentially practice-changing data.

RESULTS

Fifty-one articles met eligibility criteria and form the evidentiary basis for the recommendations.

RECOMMENDATIONS

Alpelisib in combination with endocrine therapy (ET) should be offered to postmenopausal patients, and to male patients, with HR-positive, human epidermal growth factor receptor 2 (HER2)-negative, PIK3CA-mutated, ABC, or MBC following prior endocrine therapy with or without a cyclin-dependent kinase (CDK) 4/6 inhibitor. Clinicians should use next-generation sequencing in tumor tissue or cell-free DNA in plasma to detect PIK3CA mutations. If no mutation is found in cell-free DNA, testing in tumor tissue, if available, should be used as this will detect a small number of additional patients with PIK3CA mutations. There are insufficient data at present to recommend routine testing for ESR1 mutations to guide therapy for HR-positive, HER2-negative MBC. For BRCA1 or BRCA2 mutation carriers with metastatic HER2-negative breast cancer, olaparib or talazoparib should be offered in the 1st-line through 3rd-line setting. A nonsteroidal aromatase inhibitor (AI) and a CDK4/6 inhibitor should be offered to postmenopausal women with treatment-naïve HR-positive MBC. Fulvestrant and a CDK4/6 inhibitor should be offered to patients with progressive disease during treatment with AIs (or who develop a recurrence within 1 year of adjuvant AI therapy) with or without one line of prior chemotherapy for metastatic disease, or as first-line therapy. Treatment should be limited to those without prior exposure to CDK4/6 inhibitors in the metastatic setting.Additional information can be found at www.asco.org/breast-cancer-guidelines.

Clinical outcomes of platinum-based chemotherapy in patients with advanced breast cancer: An 11-year single institutional experience

BACKGROUND/METHODS

Although the prognosis of metastatic breast cancer (BC) has improved, some patients still develop high burden metastases or visceral crisis (VC) and polychemotherapy is commonly used in these cases. Data reporting the real effectiveness of this strategy are scanty. Therefore, the outcomes of patients with metastatic BC treated with platinum-based chemotherapy (P-ChT) at the Jules Bordet Institute during the period of January 2008 and December 2018 were retrospectively reviewed. The presence of VC was defined according to ABC 4 criteria.

RESULTS

441 patients were identified: visceral metastases were observed in 430 (97.5%) while 261 (59.2%) presented VC. As for metastatic BC subtype, 255 (57.8%) had ER-positive/HER2-negative, 41 (9.3%) ER-positive/HER2-positive, 34 (7.7%) ER-negative/HER2-positive and 111 (25.1%) triple-negative BC. Median number of prior treatment lines was 3.8 (0-12). Median OS with P-ChT in the entire cohort was 6.13 months. Patients with VC had lower OS than patients without VC (8.6 vs 3.7 months; p < 0.001). On multivariate analysis, the variables correlated with worse OS were hyperbilirubinemia (HR 1.90; 95% CI 1.34-2.75), ECOG ≥2 (HR 1.77; 95% CI 1.13-2.78) and ECOG ≥3 (HR 2.52; 95% CI 1.48-4.28), and >3 previous treatment lines (HR 2.27; 95% CI 1.53-3.21). Of the 261 patients with VC, 106 (40.5%) presented a resolution of the VC which correlated with better OS (9.3 vs 2.0 months, HR 0.27; 95% CI 0.21-0.36).

CONCLUSION

Patients who overcome VC benefit from P-ChT with OS similar to patients without VC. In this analysis, hyperbilirubinemia, poor ECOG and >3 previous treatment lines were significant prognostic factors in the overall study population.

Chemotherapy or endocrine therapy, first-line treatment for patients with hormone receptor-positive HER2-negative metastatic breast cancer in China: a real-world study

Background

Although endocrine therapy (ET) is the preferred option for hormone receptor-positive HER2-negative metastatic breast cancer (HR+/HER2- MBC), chemotherapy (CT) is still commonly used. The objective of this real-world study was to present the actual choice of first-line treatment for patients with HR+/HER2- MBC and evaluate the consistency with guidelines in China.

Methods

Patients with HR+/HER2- MBC between 1996 and September 2018 were identified from of the database of Chinese Society of Clinical Oncology Breast Cancer (CSCO BC). The statistical description was conducted to present the first-line treatment. Factors influencing the prescription of ET or CT were obtained using univariate and multivariate analysis. The consistency of the actual treatment with the guideline of Chinese Society of Clinical Oncology Breast Cancer (CSCO BC guideline) was evaluated.

Results

Of 1,877 patients, 662 (35.3%) received ET, and 1,215 (64.7%) received CT. ET proportion was only 25.4% in 1996-2005 and gradually increased to 44.6% in 2016-2018. Aromatase inhibitors (69% of ET) and taxane-based regimens (66% of CT) were the most commonly used ET and CT, respectively. Univariate and multivariate analysis showed that patients with age ≥60, distant relapse-free interval (DRFI) ≥24 months, ER+/PR+, bone metastasis only, or progression on (neo)adjuvant ET were preferably chosen for ET as first-line treatment. Factors associated with preferring CT were de novo stage IV, liver or lung metastasis. 17.2% of patients (322 cases) who had neither visceral metastasis nor progression on (neo)adjuvant ET wrongly received CT instead of ET, which is inconsistent with CSCO BC guideline. More than half of patients receiving CT discontinued their initial treatment due to adverse events and other non-disease progression reasons.

Conclusions

Although high proportion of HR+/HER2- MBC patients received CT as first-line treatment in China, it is gratifying to see that the proportion of patients receiving ET has gradually increased. Our study revealed that 17.2% of patients were over-treated according to CSCO BC guideline, which may provide data to promote guideline adherence. The clinical application for ET should be appropriately expanded in first-line treatment, especially for patients without visceral disease and proof of endocrine resistance.

New insights into patterns of first metastatic sites influencing survival of patients with hormone receptor-positive, HER2-negative breast cancer: a multicenter study of 271 patients

Background

The initial therapeutic strategy for hormone receptor-positive (HR+), HER2-negative (HER2-) breast cancer is based on the first metastatic site; however, little evidence is available regarding the influence of metastatic distribution patterns of first metastatic sites on prognosis. In this study, we aimed to identify the metastatic distribution patterns of first metastatic sites that significantly correlate with survival after recurrence.

Methods

We performed a retrospective review of records from 271 patients with recurrent metastatic HR+/HER2- breast cancer diagnosed between January 2000 and December 2015. We assessed survival after recurrence according to the metastatic distribution patterns of the first metastatic sites and identified significant prognostic factors among patients with single and multiple metastases.

Results

Prognosis was significantly better in patients with a single metastasis than in those with multiple metastases (median overall survival after recurrence: 5.86 years vs. 2.50 years, respectively, p < 0.001). No metastatic organ site with single metastasis was significantly associated with prognostic outcome, although single metastasis with diffuse lesions was an independent risk factor for worse prognosis (HR: 3.641; 95% CI: 1.856–7.141) and more easily progressing to multiple metastases (p = 0.002). Multiple metastases, including liver metastasis (HR: 3.145; 95% CI: 1.802–5.495) or brain metastasis (HR: 3.289; 95% CI: 1.355–7.937), were regarded as significant independent poor prognostic factors; however, multiple metastases not involving liver or brain metastasis were not significantly related to prognosis after recurrence.

Conclusions

Single metastases with diffuse lesions could more easily disseminate systemically and progress to multiple metastases, leading to a poor prognosis similar to multiple metastases. Our findings indicate that the reconsideration of the determinant factors of therapeutic strategies for first recurrence in HR+/HER2- breast cancer may be needed.

Reporting of harms in oncological clinical study reports submitted to the European Medicines Agency compared to trial registries and publications-a methodological review

BACKGROUND

An accurate and comprehensive assessment of harms is a fundamental part of an accurate weighing of benefits and harms of an intervention when making treatment decisions; however, harms are known to be underreported in journal publications. Therefore, we sought to compare the completeness of reporting of harm data, discrepancies in harm data reported, and the delay to access results of oncological clinical trials between three sources: clinical study reports (CSRs), clinical trial registries and journal publications.

METHODS

We used the EMA clinical data website to identify all trials submitted to the EMA between 2015 and 2018. We retrieved all CSRs and included all phase II, II/III or III randomised controlled trials (RCTs) assessing targeted therapy and immunotherapy for cancer. We then identified related records in clinical trial registries and journals. We extracted harms data for eight pre-specified variables and determined the completeness of reporting of harm data in each of the three sources.

RESULTS

We identified 42 RCTs evaluating 13 different drugs. Results were available on the EMA website in CSRs for 37 (88%) RCTs, ClinicalTrials.gov for 36 (86%), the European Clinical Trials Register (EUCTR) for 20 (48%) and in journal publications for 32 (76%). Harms reporting was more complete in CSRs than other sources. We identified marked discrepancies in harms data between sources, e.g. the number of patients discontinuing due to adverse events differed in CSRs and clinical trial registers for 88% of trials with data in both sources. For CSRs and publications, the corresponding number was 90%. The median (interquartile range) delay between the primary trial completion date and access to results was 4.34 (3.09-7.22) years for CSRs, 2.94 (1.16-4.52) years for ClinicalTrials.gov, 5.39 (4.18-7.33) years for EUCTR and 2.15 (0.64-5.04) years for publications.

CONCLUSIONS

Harms of recently approved oncological drugs were reported more frequently and in more detail in CSRs than in trial registries and journal publications. Systematic reviews seeking to address harms of oncological treatments should ideally use CSRs as the primary source of data; however, due to problems with access, this is currently not feasible.

Patterns of treatment and outcome of palbociclib plus endocrine therapy in hormone receptor-positive/HER2 receptor-negative metastatic breast cancer: a real-world multicentre Italian study

Background

The CDK4/6 inhibitor palbociclib combined with endocrine therapy (ET) has proven to prolong progression-free survival (PFS) in women with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC). Few data are available regarding the efficacy of such a regimen outside the clinical trials.

Patients and methods

This is a multicentre prospective real-world experience aimed at verifying the outcome of palbociclib plus ET in an unselected population of MBC patients. The primary aim was the clinical benefit rate (CBR); secondary aims were the median PFS, overall survival (OS) and safety. Patients received palbociclib plus letrozole 2.5 mg (cohort A) or fulvestrant 500 mg (cohort B).

Results

In total, 191 patients (92 in cohort A, 99 in cohort B) were enrolled and treated, and 182 were evaluable for the analysis. Median age was 62 years (range 47-79); 54% had visceral involvement; 28% of patients had previously performed one treatment line (including chemotherapy and ET), 22.6% two lines and 15.9% three. An overall response rate of 34.6% was observed with 11 (6.0%) complete responses and 52 (28.6%) partial responses. Stable disease was achieved by 78 patients (42.9%) with an overall CBR of 59.8%. At a median follow-up of 24 months (range 6-32), median PFS was 13 months without significant differences between the cohorts. When analysed according to treatment line, PFS values were significantly prolonged when palbociclib-based therapy was administered as first-line treatment (14.0 months), to decrease progressively in second and subsequent lines (11.7 and 6.7 months, respectively). Median OS was 25 months, ranging from 28.0 months in 1st line to 18.0 and 13.0 months in 2nd and subsequent lines, respectively.

Conclusions

Our data indicate that palbociclib plus ET is active and safe in HR+/HER2- MBC, also suggesting a better performance of the combinations in earlier treatment lines.

Risk and prognostic factors of breast cancer with liver metastases

Background

Liver metastasis is a significant adverse predictor of overall survival (OS) among breast cancer patients. The purpose of this study was to determine the risk and prognostic factors of breast cancer with liver metastases (BCLM).

Methods

Data on 311,573 breast cancer patients from the Surveillance, Epidemiology, and End Results (SEER) database and 1728 BCLM patients from Fudan University Shanghai Cancer Center (FUSCC) were included. Logistic regression was used to identify risk factors for liver metastasis. Cox proportional hazards regression model was adopted to determine independent prognostic factors in BCLM patients.

Results

Young age, invasive ductal carcinoma, higher pathological grade, and subtype of triple-negative and human epidermal growth factor receptor 2 positive (HER2+) were risk factors for developing liver metastasis. The median OS after liver metastasis was 20.0 months in the SEER database and 27.3 months in the FUSCC dataset. Molecular subtypes also played a critical role in the survival of BCLM patients. We observed that hormone receptor-positive (HR+)/HER2+ patients had the longest median OS (38.0 for SEER vs. 34.0 months for FUSCC), whereas triple-negative breast cancer had the shortest OS (9.0 vs. 15.6 months) in both SEER and FUSCC. According to the results from the FUSCC, the subtype of HR+/HER2+ (hazard ratio (HR) = 2.62; 95% confidence interval (CI) = 1.88–3.66; P < 0.001) and HR−/HER2+ (HR = 3.43; 95% CI = 2.28–5.15; P < 0.001) were associated with a significantly increased death risk in comparison with HR+/HER2- patients if these patients did not receive HER2-targeted therapy. For those who underwent HER2-targeted therapy, however, HR+/HER2+ subtype reduced death risk compared with HR+/HER2- subtype (HR = 0.74; 95% CI = 0.58–0.95; P < 0.001).

Conclusions

Breast cancer patients at a high risk for developing liver metastasis deserve more attention during the follow-up. BCLM patients with HR+/HER2+ subtype displayed the longest median survival than HR+/HER2- and triple-negative patients due to the introduction of HER2-targeted therapy and therefore it should be recommended for HER2+ BCLM patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07968-5.

Real-world safety of palbociclib in breast cancer patients in the United States: a new user cohort study

Background

There is limited real-world safety information on palbociclib for treatment of advanced stage HR+/HER2- breast cancer.

Methods

We conducted a cohort study of breast cancer patients initiating palbociclib and fulvestrant from February 2015 to September 2017 using the HealthCore Integrated Research Database (HIRD), a longitudinal claims database of commercial health plan members in the United States.

The historical comparator cohort comprised patients initiating fulvestrant monotherapy from January 2011 to January 2015. Propensity score matching and Cox regression were used to estimate hazard ratios for various safety events. For acute liver injury (ALI), additional analyses and medical record validation were conducted.

Results

There were 2445 patients who initiated palbociclib including 566 new users of palbociclib-fulvestrant, and 2316 historical new users of fulvestrant monotherapy. Compared to these historical new users of fulvestrant monotherapy, new users of palbociclib-fulvestrant had a greater than 2-fold elevated risk for neutropenia, leukopenia, thrombocytopenia, stomatitis and mucositis, and ALI. Incidence of anemia and QT prolongation were more weakly associated, and incidences of serious infections and pulmonary embolism were similar between groups after propensity score matching. After adjustment for additional ALI risk factors, the elevated risk of ALI in new users of palbociclib-fulvestrant persisted (e.g. primary ALI algorithm hazard ratio (HR) = 3.0, 95% confidence interval (CI) = 1.1–8.4).

Conclusions

This real-world study found increased risks of several adverse events identified in clinical trials, including neutropenia, leukopenia, and thrombocytopenia, but no increased risk of serious infections or pulmonary embolism when comparing new users of palbociclib-fulvestrant to fulvestrant monotherapy. We observed an increased risk of ALI, extending clinical trial findings of significant imbalances in grade 3/4 elevations of alanine aminotransferase (ALT).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07790-z.

Real-World Clinical Data of Palbociclib in Asian Metastatic Breast Cancer Patients: Experiences from Eight Institutions

Purpose

Use of cyclin-dependent kinase 4/6 inhibitors improved survival outcome of hormone receptor (HR) positive metastatic breast cancer (MBC) patients, including Asian population. However, Asian real-world data of palbociclib is limited. We analyzed the real-world clinical practice patterns and outcome in HR-positive, MBC Asian patients treated with palbociclib.

Materials and Methods

Between April 2017 to November 2019, 169 HR-positive, human epidermal growth factor-2–negative MBC patients treated with letrozole or fulvestrant plus palbocilib were enrolled from eight institutions. Survival outcome (progression-free survival [PFS]), treatment response and toxicity profiles were analyzed.

Results

Median age of letrozole plus palbociclib (145 patients, 85.8%) and fulvestrant plus palbociclib (24 patients, 14.2%) was 58 and 53.5 years, with median follow-up duration of 14.63 months (range 0.2 to 33.9 months). Median PFS (mPFS) of letrozole plus palbociclib and fulvestrant plus palbociclib was 25.6 (95% confidence interval [CI], 19.1 to not reached) and 6.37 months (95% CI, 5.33 to not reached), comparable to previous phase 3 trials. In letrozole plus palbociclib arm, luminal A (hazard ratio, 2.86; 95% CI, 1.20 to 6.80; p=0.017) and patients with good performance (Eastern Cooperative Oncology Group 0–1 [hazard ratio, 3.68; 95% CI, 1.70 to 7.96]) showed better mPFS. In fulvestrant plus palbociclib group, chemotherapy naïve patients showed better mPFS (hazard ratio, 12.51, 95% CI, 1.59 to 99.17; p=0.017). The most common grade 3 or 4 adverse event was neutropenia (letrozole 86.3%, fulvestrant 88.3%).

Conclusion

To our knowledge, this is the first real-world data of palbociclib reported in Asia. Palbociclib showed comparable benefit to previous phase 3 trials in Asian patients during daily clinical practice.

CDK4/6 Inhibitors in Hormone Receptor-Positive Metastatic Breast Cancer: Current Practice and Knowledge

Treatment paradigms in advanced hormone receptor (HR)-positive breast cancer were substantially transformed with cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) approval. The addition of these drugs to endocrine treatment profoundly improved progression-free and overall survival. Additionally, other important endpoints, such as the response rate, time to chemotherapy, and a delay in quality of life deterioration, were positively impacted by CDK4/6 inhibitors' addition to the treatment of advanced HR-positive breast cancer. This review article will summarize current knowledge on CDK4/6 inhibitors in clinical practice for advanced HR-positive metastatic breast cancer, as well as describe recent efforts to more precisely characterize mechanisms of sensitivity and resistance to these drugs, both on the molecular and clinical characterization level.

Treatment effect of palbociclib plus endocrine therapy by prognostic and intrinsic subtype and biomarker analysis in patients with bone-only disease: a joint analysis of PALOMA-2 and PALOMA-3 clinical trials

Purpose

This analysis evaluated the relationship between treatment-free interval (TFI, in PALOMA-2)/disease-free interval (DFI, in PALOMA-3) and progression-free survival (PFS) and overall survival (OS, in PALOMA-3), treatment effect in patients with bone-only disease, and whether intrinsic subtype affects PFS in patients receiving palbociclib.

Methods

Data were from phase 3, randomized PALOMA-2 and PALOMA-3 clinical studies of hormone receptor‒positive/human epidermal growth factor receptor 2‒negative (HR+ /HER2−) advanced breast cancer (ABC) patients receiving endocrine therapy plus palbociclib or placebo. Subpopulation treatment effect pattern plot (STEPP) analysis evaluated the association between DFI and PFS and OS. PFS by luminal subtype and cyclin-dependent kinase (CDK) 4/6 or endocrine pathway gene expression levels were evaluated in patients with bone-only disease; median PFS and OS were estimated by the Kaplan–Meier method.

Results

Median durations of TFI were 37.1 and 30.9 months (PALOMA-2) and DFI were 49.2 and 52.0 months (PALOMA-3) in the palbociclib and placebo groups, respectively. Among the PALOMA-2 biomarker population (n = 454), 23% had bone-only disease; median PFS was longer with palbociclib versus placebo (31.3 vs 11.2 months; hazard ratio, 0.41; 95% CI 0.25‒0.69). The interaction effect of bone-only versus visceral disease subgroups on median PFS with palbociclib was not significant (P = 0.262). Among the PALOMA-3 biomarker population (n = 302), 27% had bone-only disease. STEPP analyses showed that palbociclib PFS benefit was not affected by DFI, and that palbociclib OS effect may be smaller in patients with short DFIs. Among patients who provided metastatic tumor tissues (n = 142), regardless of luminal A (hazard ratio, 0.23; 95% CI 0.11‒0.47; P = 0.0000158) or luminal B (hazard ratio, 0.26; 95% CI 0.12‒0.56; P = 0.000269) subtype, palbociclib improved PFS versus placebo.

Conclusions

These findings support palbociclib plus endocrine therapy as standard of care for HR+ /HER2− ABC patients, regardless of baseline TFI/DFI or intrinsic molecular subtype, including patients with bone-only disease.

Trial registration

Pfizer (clinicaltrials.gov:NCT01740427, NCT01942135).

Endocrine therapy-based treatments in hormone receptor-positive/HER2-negative advanced breast cancer: systematic review and network meta-analysis

BACKGROUND

Several endocrine therapy (ET)-based treatments are available for patients with advanced breast cancer. We assessed the efficacy of different ET-based treatments in patients with hormone receptor-positive/HER2-negative advanced breast cancer with endocrine-sensitive or endocrine-resistant disease.

METHODS

We searched Medline and Cochrane Central Register of Controlled Trials up to 15 October 2019 and abstracts from major conferences from 2016 to October 2019. We included phase II/III randomised trials, comparing ≥2 ET-based treatments. Progression-free survival (PFS) and overall survival (OS) were analysed by network meta-analyses using MTC Bayesian models based on both fixed-effect and random-effect models; relative treatment effects were measured as HRs and 95% credibility intervals (CrI). All statistical tests were two-sided. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed and this systematic review is registered in the PROSPERO database.

RESULTS

55 publications reporting on 32 trials (n=12 293 patients) were included. Regarding PFS in the endocrine sensitive setting (n=5200; 12 trials), the combination of cyclin-dependent kinases (CDK)4/6-inhibitors (CDK4/6i)+fulvestrant 500 mg (F500) was likely the most effective treatment (surface under the cumulative ranking curve (SUCRA)=97.3%), followed by CDK4/6i+aromatase inhibitor ±goserelin; there was no significant difference between them (HR 0.82; 95% CrI 0.54-1.25). Regarding OS (n=2157; five trials), the most effective treatment was probably CDK4/6i+F500 (SUCRA=97.3%); comparing CDK4/6i+F500 versus F500 held a HR of 0.77 (95% CrI 0.63-0.95). Regarding PFS in the endocrine-resistant setting (n=6635; 20 trials), CDK4/6i+F500 was likely the most effective treatment (SUCRA=95.7%), followed by capivasertib+F500, without significant difference between them (HR 0.91; 95% CrI 0.60-1.36). For OS (n=4377; 11 trials), the most effective treatments were capivasertib+F500 (SUCRA=84.7%) and CDK4/6i+F500 (SUCRA=69.9%). Comparing CDK4/6i+F500 versus F500 held a HR of 0.77 (95% CrI 0.67-0.89).

CONCLUSIONS

CDK4/6i+F500 is likely the best treatment option in both endocrine-sensitive and endocrine-resistant diseases for PFS, and in endocrine-sensitive patients for OS. Concerning OS in endocrine-resistant patients, capivasertib+F500 and CDK4/6i+F500 are likely the best treatments.

PROSPERO REGISTRATION NUMBER

CRD42018104628.

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.

Real-World Treatment Patterns and Clinical Outcomes in Patients Receiving Palbociclib for Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced or Metastatic Breast Cancer in Argentina: The IRIS Study

PURPOSE

The selective cyclin-dependent kinase 4/6 inhibitor palbociclib was approved in Argentina in 2015 for postmenopausal women with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC) or metastatic breast cancer (MBC) based on phase III study results. The Ibrance Real World Insights (IRIS) study aims to evaluate palbociclib in patients with HR-positive/HER2-negative ABC or MBC in the real-world setting in multiple countries globally. Here we report results from patients enrolled in the IRIS study in Argentina.

PATIENTS AND METHODS

This retrospective medical chart review study included postmenopausal women with confirmed HR-positive/HER2-negative ABC or MBC who were treated with palbociclib plus letrozole as first-line endocrine-based therapy or with palbociclib plus fulvestrant in women with disease progression after endocrine therapy. Participating physicians reviewed medical records of up to six patients each, collecting demographic and clinical data. Outcomes included progression-free and overall survival rates.

RESULTS

Records were extracted for 162 patients in Argentina (palbociclib plus letrozole, n = 105 [65%]; palbociclib plus fulvestrant, n = 57 [35%]). The 6-month progression-free survival rate was 94% for patients treated with palbociclib plus letrozole and 95% for patients treated with palbociclib plus fulvestrant; 85% and 80% of patients treated with palbociclib plus letrozole were progression free at 12 and 18 months, respectively. Six-month survival rates were 98% for palbociclib plus letrozole and 98% for palbociclib plus fulvestrant; 93% and 89% of patients treated with palbociclib plus letrozole were alive at 12 and 18 months, respectively.

CONCLUSION

Results from this first real-world evaluation of clinical outcomes in Argentina suggest that palbociclib plus letrozole or fulvestrant delivers favorable effectiveness, as measured by progression-free and overall survival rates.

METTL14 promotes the migration and invasion of breast cancer cells by modulating N6‑methyladenosine and hsa‑miR‑146a‑5p expression

Breast cancer (BC) is the most frequently diagnosed cancer and the leading cause of cancer-related death among women worldwide. Evidence indicates that posttranscriptional N6-methyladenosine (m6A) modification modulates BC development. In the present study, we assessed BC and normal tissues to investigate this connection. RNA m6A levels were determined by methylation quantification assay. The effects of methyltransferase-like 14 (METTL14) gain-of-expression or co-transfection with an m6A inhibitor on cell migration and invasion abilities were determined by Transwell assays. The levels of differentially expressed (DE) miRNAs were verified by real-time quantitative PCR (RT-qPCR). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes analyses (KEGG) were performed to analyze potential function of target genes of the DE miRNAs. The effects of candidate miRNAs modulated by METTL14 on cell migration and invasion abilities were confirmed by Transwell assays. We demonstrated that m6A methyltransferase METTL14 was significantly upregulated in BC tissues compared with normal tissues. METTL14 gain- and loss-of-expression regulated m6A levels in MCF-7 and MDA-MB-231 cells. The cell function assays revealed that METTL14 overexpression enhanced the migration and invasion capacities of BC cells. Moreover, treatment with the m6A inhibitor suppressed this enhanced cell migration and invasion. Additionally, aberrant expression of METTL14 reshaped the miRNA profile in BC cell lines. The remodeled DE miRNA/mRNA network was found to be most enriched in cancer pathways, and DE miRNAs were enriched in cell adhesion terms. hsa-miR-146a-5p modulated by METTL14 promoted cell migration and invasion. METTL14 modulates m6A modification and hsa-miR-146a-5p expression, thereby affecting the migration and invasion of breast cancer cells.

Comparative Efficacy of CDK4/6 Inhibitors Plus Aromatase Inhibitors Versus Fulvestrant for the First-Line Treatment of Hormone Receptor-Positive Advanced Breast Cancer: A Network Meta-Analysis

BACKGROUND

Several endocrine therapies are available for postmenopausal women with hormone receptor-positive (HR +) advanced breast cancer (ABC). Given the absence of direct comparisons between fulvestrant and cyclin-dependent kinase 4/6 inhibitors (CDK4/6is) in combination with aromatase inhibitors (AIs), which are both used as standard first-line treatments for ABC, an indirect comparison using a network meta-analysis may be advantageous for decision making.

OBJECTIVE

We performed a network meta-analysis to compare the efficacies of fulvestrant and CDK4/6is plus AIs as the first-line treatment of postmenopausal breast cancer patients.

PATIENTS AND METHODS

In order to compare these treatments, we searched the PubMed, Cochrane Library, and EMBASE databases for randomized controlled trials of first-line endocrine treatment for advanced or metastatic breast cancer until October 2018. We included a total of 11 eligible trials with 5448 patients. The hazard ratios (HRs) for the efficacies of the different treatments were used as inputs in the network meta-analysis.

RESULTS

In the overall analysis, CDK4/6is plus AIs, including palbociclib plus letrozole, ribociclib plus letrozole, and abemaciclib plus nonsteroidal AI (letrozole or anastrozole), are all superior to 500 mg fulvestrant (HR = 0.50, 95% confidence interval [CI] 0.37-0.68; HR = 0.50, 95% CI 0.35-0.71; and HR = 0.49, 95% CI 0.34-0.71; respectively).

CONCLUSIONS

Within the limitations of this network meta-analysis, the comparison indicates that CDK4/6is plus AIs might represent a better option for HR+ ABC as a first-line endocrine treatment compared with fulvestrant.

Systemic Treatments in Pregnancy-Associated Breast Cancer

Available data on systemic treatments in pregnancy-associated breast cancer (PABC) is reviewed in this section. These treatments include chemotherapy, endocrine therapy (ET), small molecule inhibitors, monoclonal antibodies against human epidermal growth factor receptor 2 (EGFR-2) also known as HER2; and human epidermal growth factor receptor 3 (EGFR-3), also known as HER3.In local disease, systemic treatment can be delivered as neoadjuvant (before surgery) or adjuvant (after surgery) treatment. In metastatic disease, systemic therapy is the main modality of treatment.Approach to PABC is based on available data in the general population, limited only by safety issues for use of medications during gestation and lactation. Therefore, treatments are similar to non-PABC patients while trying to minimize the risk to the fetus. Available data on different chemotherapies, anti-HER2 monoclonal antibodies, ET and small molecule inhibitors are discussed in detail.

Endocrine therapy for hormone receptor-positive, HER2-negative metastatic breast cancer: extending endocrine sensitivity

Targeted agents have significantly prolonged survival and improved response rates in first- and second-line settings of hormone receptor-positive/HER2-negative metastatic breast cancer. Optimal sequencing of the available options may prolong endocrine sensitivity, slow disease progression and delay the need for chemotherapy. However, the optimal treatment sequence remains unclear and therapeutic decisions are complex. We review the latest recommendations and supporting evidence for endocrine therapy in women with hormone receptor-positive/HER2-negative metastatic breast cancer and discuss strategies for the optimal sequential therapy in scenarios of response to endocrine therapy. Although more data are needed to define the best sequence of endocrine treatments, more personalized sequential strategies, which take into account response to previous treatments as well as disease symptoms and safety issues, will be increasingly feasible.

CDK4/6 inhibition in low burden and extensive metastatic breast cancer: summary of an ESMO Open-Cancer Horizons pro and con discussion

In December 2017, ESMO Open-Cancer Horizons convened a round-table discussion on the background and latest data regarding cyclin-dependent kinase (CDK)4/6 inhibitors with endocrine therapy (ET) in the treatment of endocrine-sensitive breast cancer (BC). A review on this discussion was published in summer 2018 (https://esmoopen.bmj.com/content/3/5/e000368).Endocrine-sensitive BC with non-visceral disease and limited spread of the metastases.Endocrine-sensitive BC with non-life-threatening visceral involvement. Several open questions were identified, which led to a second ESMO Open discussion on CDK4/6 inhibitors, taking place in December 2018 and covered in this article. The panel discussed two important clinical scenarios and the pro and cons of a treatment approach with CDK4/6 inhibitors for each scenario:Endocrine-sensitive BC with non-visceral disease and limited spread of the metastases.Endocrine-sensitive BC with non-life-threatening visceral involvement. Regarding scenario 1, the panel agreed that CDK4/6 inhibitors should be recommended in first-line therapy for most patients if cost and practicality allow. However, the use of single-agent ET with an aromatase inhibitor in the first-line treatment of these patients is still a possibility for a small group of patients with very limited disease, such as one or two bone lesions or limited lymph node involvement. Regarding scenario 2, chemotherapy is the first approach for patients with endocrine-sensitive metastatic BC with life-threatening visceral involvement because of the need for a faster response. The therapeutic approaches for patients with non-life-threatening visceral involvement are still under debate. Nevertheless, CDK4/6 inhibitors are currently the treatment of choice for most patients with a close follow-up of tumour response. A treatment algorithm has been suggested at the round table.

Efficacy and Safety of Palbociclib and Fulvestrant in Japanese Patients With ER+/HER2- Advanced/Metastatic Breast Cancer

BACKGROUND/AIM

Published data have shown that palbociclib-fulvestrant can significantly improve the progression-free survival (PFS) of estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) metastatic breast cancer patients, but not of Japanese patients. We conducted this retrospective study to verify the efficacy and safety of palbociclib-fulvestrant in Japanese patients.

PATIENTS AND METHODS

ER+/HER2- metastatic breast cancer patients treated with fulvestrant (n=39) or palbociclib-fulvestrant (n=31) at the Saitama Medical Center from July 2012 to November 2018 were evaluated.

RESULTS

Overall response rates (ORRs) were 2.6% (fulvestrant) and 41.9% (palbociclib-fulvestrant) (p<0.001), and clinical benefit rates (CBRs) were 23.1% and 61.3% (p=0.002), respectively. The palbociclib-fulvestrant group had significantly higher CBR and PFS (hazard ratio(HR):0.272, 95% confidence interval(95CI):0.128-0.574 for PFS). Grade 3/4 neutropenia occurred in 80.6% of the palbociclib-fulvestrant group, while febrile neutropenia was not detected.

CONCLUSION

Japanese ER+/HER2- metastatic breast cancer patients tolerated palbociclib-fulvestrant, with significantly improved clinical outcomes.

First-Line Treatment for Endocrine-Sensitive Bone-Only Metastatic Breast Cancer: Systematic Review and Meta-analysis

In the last decade, several clinical trials have investigated novel endocrine combinations for the first-line treatment of hormone receptor-positive metastatic breast cancer. Nevertheless, the use of combinations for the first-line treatment of bone-only disease is widely discussed as a result of its indolent natural history. We performed a comprehensive search of phase 3 randomized clinical trials published in the literature through September 2018. Our aim was to explore the role of the new endocrine approaches in bone-only metastatic breast cancer, suggesting a possible strategy for their selection. In particular, we evaluated the comparative risk of adverse event occurrence during these treatments. A total of 6 studies were deemed suitable for meta-analysis: the Monaleesa-2, Monaleesa-7, Monarch-3, Paloma-2, SWOG, and Alliance trials. Overall, the novel strategies were shown to improve progression-free survival in bone-only disease (hazard ratio = 0.65; 95% confidence interval, 0.49-0.86; P = .003). Combinations with cyclin-dependent kinase inhibitors improved progression-free survival (hazard ratio = 0.54; 95% confidence interval, 0.39-0.75; P < .001) with an acceptable toxicity profile. Abemaciclib was associated with increased anemia and gastrointestinal toxicity (especially diarrhea), whereas palbociclib was associated with increased leukopenia (but not neutropenia) compared to the other compounds. Increased aspartate aminotransferase levels were reported for both ribociclib and abemaciclib. The combination of cyclin-dependent kinase 4/6 inhibitors and endocrine therapy represents an effective and well-tolerated approach for first-line treatment in bone-only disease settings. Because no direct comparison between the 3 cyclin-dependent kinase 4/6 inhibitors is available, the selection of the most appropriate treatment should be based on toxicity profile as well as patient preference and copathologies.

Palbociclib in metastatic breast cancer: current evidence and real-life data

The purpose of this review is to summarize the background and latest evidence for the use of palbociclib, an oral, first-in-class, highly selective cyclin-dependent kinase 4/6 inhibitor, in advanced breast cancer, with a focus on some of the unanswered questions about the performance of this agent in clinical practice. The available clinical data from both controlled clinical trials and real-life experiences concerning palbociclib-based combinations in patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic disease, including patient-reported outcomes and subgroup analyses, have been reviewed and discussed. Palbociclib significantly improved progression-free survival and clinical benefit rates when added to letrozole in postmenopausal women as initial endocrine-based therapy, and it prolonged progression-free survival and overall survival when added to fulvestrant in women who progressed on previous endocrine therapy in randomized clinical trials. Tolerability profile was manageable, with neutropenia occurring most commonly, without detrimental impact on quality of life. Available data from real-life experiences confirm the good performance of palbociclib in unselected, heavily pretreated populations. Palbociclib in combination with endocrine therapy is a valuable emerging option for patients with HR+/HER2- advanced or metastatic breast cancer. Further investigation is needed to provide solutions for palbociclib resistance and to identify the best sequence to use for the best patient benefit with a minimal toxicity.