Can Women With HER2-Positive Metastatic Breast Cancer Be Cured?

The Impact of Initial Tumor Response on Survival Outcomes of Patients With HER2-Positive Advanced Breast Cancer Treated With Docetaxel, Trastuzumab, and Pertuzumab: An Exploratory Analysis of the CLEOPATRA Trial

INTRODUCTION

The CLEOPATRA trial (NCT00567190) established a dual anti-HER2 blockade in combination with docetaxel as the first-line standard of care for patients with metastatic HER2-positive breast cancer. While this treatment is overall associated with significant improvement in progression-free survival (PFS) and overall survival (OS), not all patients respond equally. We hypothesized that a radiological complete response (CR) at week 9 (i.e., first disease re-evaluation) is associated with prolonged OS and PFS compared to radiological partial response (PR) or stable disease (SD).

METHODS

We performed an exploratory analysis of the CLEOPATRA study to address this question.

RESULTS

Out of 362 patients treated with docetaxel, trastuzumab, and pertuzumab eligible for our analysis, 46 (12.7%) had radiological CR at week 9, 243 (67.1%) PR, and 73 (20.2%) SD per central RECIST v1.0. Radiological CR at first tumor re-evaluation was associated with a 60% risk reduction for death compared to SD (adjusted HR = 0.40 95% confidence interval (CI) 0.23-0.70), whereas no significant impact on survival was observed for PR (adjusted HR = 0.85 95% CI 0.60-1.20). The same was observed for PFS with adjusted HR = 0.30 (95% CI 0.18-0.48) for the CR subgroup and adjusted HR = 0.81 (95% CI 0.60-1.09) for the PR subgroup. In multivariate analysis, no variables were associated with radiological CR.

CONCLUSIONS

Our findings suggest that radiological CR at first disease re-evaluation is associated with more prolonged survival; this might result from stronger dependence on HER2 pathway addiction, supporting the need for further translational research.

Metastatic HER2-Positive Breast Cancer: Is There an Optimal Sequence of Therapy?

OPINION STATEMENT

Approximately 20% of breast cancers overexpress human epidermal growth factor receptor 2 (HER2+), conferring a particularly aggressive subtype of the disease with an increased risk for the development of systemic and brain metastases. However, the advent of trastuzumab and more recently several other HER2-targeting novel therapies has led to significant improvements in the prognosis, making the diagnosis a "double-edged sword." The current standard first-line therapy for patients with HER2+ metastatic breast cancer (MBC) is a taxane combined with trastuzumab and pertuzumab. Trastuzumab deruxtecan should be used preferentially in the second line, with the only caveat being patients with CNS involvement where the tucatinib, capecitabine, and trastuzumab regimen could be considered. In the third line setting, given the survival benefits demonstrated with the tucatinib regimen in patients with and without CNS metastases, this is the preferred strategy. In the fourth line and beyond, there is no clear standard. Options include margetuximab in combination with chemotherapy, neratinib + capecitabine, or trastuzumab + chemotherapy. There are several novel therapies under investigation reporting promising results in the late-line setting. The treatment landscape of HER2-positive advanced disease is evolving constantly, with several active therapies being moved to the early-stage setting. Accordingly, it will be critical to identify biomarkers and mechanisms of resistance to optimize therapy selection and maximize patient outcomes and quality of life. Here, we provide an overview of the current and future management of HER2-positive advanced breast cancer and address the specific scenarios which may impact treatment selection including triple-positive breast cancer and the presence of brain metastases. Finally, we highlight promising novel treatments and ongoing trials that may impact future treatment sequencing.

Effect of HER2 expression status on the prognosis of patients with HR+/HER2‑ advanced breast cancer undergoing advanced first‑line endocrine therapy

The present study aimed to retrospectively assess the effects of human epidermal growth factor receptor 2 (HER2) expression on the diagnosis of patients with hormone receptor (HR)⁺/HER2^- late-stage breast cancer undergoing advanced first-line endocrine-based treatment. A total of 72 late-stage breast tumor cases from June 2017 to June 2019 were selected from the Department of Surgical Oncology, Shaanxi Provincial People's Hospital (Xi'an, China) and included in the present study. The expression of estrogen receptor, progesterone receptor and HER2 was detected by immunohistochemistry. The subjects were divided into two groups: the HER2-negative (0) cohort (n=31) and the HER2 low expression cohort (n=41). The age, BMI, Karnofsky Performance Status (KPS) score, tumor size, lymph node metastasis, pathological type, Ki-67 expression and menopausal status of the patients were obtained through the electronic medical record system of Shaanxi Provincial People's Hospital. Progression-free survival (PFS) and overall survival (OS) were evaluated for all patients. The median PFS and OS of the HER2(0) cohort were longer than those of the HER2 low expression cohort (all P<0.05). It was shown that age (hazard ratio, 6.000 and 5.465), KPS score (hazard ratio, 4.000 and 3.865), lymph node metastasis (hazard ratio, 3.143; 2.983) and HER2 status (hazard ratio, 3.167 and 2.996) were independent influencing factors of the prognosis of patients with HR⁺/HER2^- advanced breast cancer (ABC) (all P<0.05). Three models (model 1, no parameters adjusted; model 2, BMI, tumor size, pathological type, Ki-67 and menopausal status adjusted; and model 3, age, KPS functional status score and lymph node metastasis adjusted based on model 2) were established within the HER2(0) cohort as the reference for statistical analysis using the multivariate Cox's regression test. In models 2 and 3, the risk of poor prognosis of ABC within the HER2 low expression cohort was significantly higher compared with that in the HER2(0) cohort (hazard ratio, 3.558 and 4.477; 95% CI, 1.349-9.996 and 1.933-11.586; P=0.003 and P<0.001). The HER2 expression status of patients with HR⁺/HER2^- ABC receiving advanced first-line endocrine therapy may affect PFS and OS.

[Dihydromyricetin reverses Herceptin resistance by up-regulating miR-98-5p and inhibiting IGF1R/HER2 dimer formation in SKBR3 cells]

OBJECTIVE

To explore the effect of dihydromyricetin on the expression of miR-98-5p and its mechanism in the development of Herceptin resistance in SKBR3 cells.

METHODS

The expression of IGF2 and miR-98-5p and their interaction relationship were analyzed by bioinformatics analysis through TargetScan online databases. SKBR3 cells and drug-resistant SKBR3-R cells were cultured in cell experiments. Xenograft tumor mice were constructed by SKBR3 and SKBR3-R cells. Proteins were detected by western blotting and immunohistochemistry. Transfected cells were constructed by shRNA lentivirus vectors. RT-QPCR was used to detect RNA. Cell proliferation was detected by MTS method. Cell jnvasion was detected by Transwell assay. Luciferase reporting assays were used to verify RNA interactions. IGF-1R/HER2 heterodimer was determined by immunocoprecipitation.

RESULTS

The expression of IGF2, p-IGF1R, p-Akt and p-S6K in SKBR3-R cells were significantly higher than those in SKBR3 cells, while the expression of PTEN protein was lower in SKBR3-R cells (P < 0.05). IGF1R/HER2 heterodimer in SKBR3-R cells was significantly increased (P < 0.01).The expression of IGF2 and invasion ability were significantly reduced while transfected with miR-98-5p in SKBR3-R cells (P < 0.05), but the IGF2 mRNA were no difference in both cells (P > 0.05). The expression of miR-98-5p was up-regulated and IGF2 was decreased in drug-resistant xenograft tumor mice after feeding with dihydromyricetin, and the tumor became more sensitivity to Herceptin (P < 0.05).

CONCLUSION

Dihydromyricetin could induce the expression of miR-98-5p, which binds to IGF2 mRNA to reduce IGF2 expression, inhibit the IGF-1R/HER2 formation, thereby reversing cell resistance to Herceptin in SKBR3-R cells.

Prognosis and Treatment of Metastatic Breast Cancer From A Real-World Scenario in China: A Retrospective Cohort Study

OBJECTIVES

Although metastatic breast cancer (MBC) is considered incurable, a specific subset of patients exhibits prolonged survival and even achieve a "cure". We retrospectively identified predictive prognostic factors and systemic therapy models to find this group of potentially cured patients.

METHODS

Consecutive patients diagnosed with MBC from 1991-2016 in West China Hospital were included. Univariate and multivariate analyses were conducted to assess the association of clinical factors and systemic therapy models with overall survival (OS), breast cancer-specific survival (BCSS) and progression-free survival (PFS).

RESULTS

The median OS was 63.4 months. Age, tumor size, lymph node metastasis, histologic grade, molecular subtype, site and number of metastases and metastasis-free interval (MFI) were related to the prognosis of MBC (P < .05). Patients with T1, N0-1, luminal A, bone metastasis, OMBC (oligometastatic breast cancer) or metastasis-free interval (MFI) ≥ 3 years showed the median OS more than 10 years (P < .001). Independent prognostic factors that correlated with OS and BCSS were residence, lymph node metastasis, histologic grade, molecular subtype, and site of metastasis (P < .05). The group of sequential chemo-endocrine therapy (ST) in hormone receptor (HR)-positive MBC patients showed the highest overall response rate (ORR) (P < .05). However, patients who received endocrine therapy (ET) showed the best OS, BCSS and PFS in the first two-line treatment, followed by ST and chemotherapy (CT) (P < .05).

CONCLUSIONS

Our study shows the predictive prognostic factors and systemic therapy models to facilitate patients likely to achieve long-term survival.