Combination of Modern Radiotherapy and New Targeted Treatments for Breast Cancer Management

Molecular Changes in Breast Cancer Induced by Radiation Therapy

PURPOSE

Breast cancer treatments are based on prognostic clinicopathologic features that form the basis for therapeutic guidelines. Although the utilization of these guidelines has decreased breast cancer-associated mortality rates over the past three decades, they are not adequate for individualized therapy. Radiation therapy (RT) is the backbone of breast cancer treatment. Although a highly successful therapeutic modality clinically, from a biological perspective, preclinical studies have shown RT to have the potential to alter tumor cell phenotype, immunogenicity, and the surrounding microenvironment, potentially changing the behavior of cancer cells and resulting in a significant variation in RT response. This review presents the recent advances in revealing the complex molecular changes induced by RT in the treatment of breast cancer and highlights the complexities of translating this information into clinically relevant tools for improved prognostic insights and the revelation of novel approaches for optimizing RT.

METHODS AND MATERIALS

Current literature was reviewed with a focus on recent advances made in the elucidation of tumor-associated radiation-induced molecular changes across molecular, genetic, and proteomic bases. This review was structured with the aim of providing an up-to-date overview over the very broad and complex subject matter of radiation-induced molecular changes and radioresistance, familiarizing the reader with the broader issue at hand.

RESULTS

The subject of radiation-induced molecular changes in breast cancer has been broached from various physiological focal points including that of the immune system, immunogenicity and the abscopal effect, tumor hypoxia, breast cancer classification and subtyping, molecular heterogeneity, and molecular plasticity. It is becoming increasingly apparent that breast cancer clinical subtyping alone does not adequately account for variation in RT response or radioresistance. Multiple components of the tumor microenvironment and immune system, delivered RT dose and fractionation schedules, radiation-induced bystander effects, and intrinsic tumor physiology and heterogeneity all contribute to the resultant RT outcome.

CONCLUSIONS

Despite recent advances and improvements in anticancer therapies, tumor resistance remains a significant challenge. As new analytical techniques and technologies continue to provide crucial insight into the complex molecular mechanisms of breast cancer and its treatment responses, it is becoming more evident that personalized anticancer treatment regimens may be vital in overcoming radioresistance.

International multidisciplinary consensus on the integration of radiotherapy with new systemic treatments for breast cancer: European Society for Radiotherapy and Oncology (ESTRO)-endorsed recommendations

Novel systemic therapies for breast cancer are being rapidly implemented into clinical practice. These drugs often have different mechanisms of action and side-effect profiles compared with traditional chemotherapy. Underpinning practice-changing clinical trials focused on the systemic therapies under investigation, thus there are sparse data available on radiotherapy. Integration of these new systemic therapies with radiotherapy is therefore challenging. Given this rapid, transformative change in breast cancer multimodal management, the multidisciplinary community must unite to ensure optimal, safe, and equitable treatment for all patients. The aim of this collaborative group of radiation, clinical, and medical oncologists, basic and translational scientists, and patient advocates was to: scope, synthesise, and summarise the literature on integrating novel drugs with radiotherapy for breast cancer; produce consensus statements on drug-radiotherapy integration, where specific evidence is lacking; and make best-practice recommendations for recording of radiotherapy data and quality assurance for subsequent studies testing novel drugs.

Impact of Imaging Biomarkers and AI on Breast Cancer Management: A Brief Review

Breast cancer stands out as the most frequently identified malignancy, ranking as the fifth leading cause of global cancer-related deaths. The American College of Radiology (ACR) introduced the Breast Imaging Reporting and Data System (BI-RADS) as a standard terminology facilitating communication between radiologists and clinicians; however, an update is now imperative to encompass the latest imaging modalities developed subsequent to the 5th edition of BI-RADS. Within this review article, we provide a concise history of BI-RADS, delve into advanced mammography techniques, ultrasonography (US), magnetic resonance imaging (MRI), PET/CT images, and microwave breast imaging, and subsequently furnish comprehensive, updated insights into Molecular Breast Imaging (MBI), diagnostic imaging biomarkers, and the assessment of treatment responses. This endeavor aims to enhance radiologists' proficiency in catering to the personalized needs of breast cancer patients. Lastly, we explore the augmented benefits of artificial intelligence (AI), machine learning (ML), and deep learning (DL) applications in segmenting, detecting, and diagnosing breast cancer, as well as the early prediction of the response of tumors to neoadjuvant chemotherapy (NAC). By assimilating state-of-the-art computer algorithms capable of deciphering intricate imaging data and aiding radiologists in rendering precise and effective diagnoses, AI has profoundly revolutionized the landscape of breast cancer radiology. Its vast potential holds the promise of bolstering radiologists' capabilities and ameliorating patient outcomes in the realm of breast cancer management.

A Comprehensive Primer on Radiation Oncology for Non-Radiation Oncologists

Background: Multidisciplinary management is crucial in cancer diagnosis and treatment. Multidisciplinary teams include specialists in surgery, medical therapies, and radiation therapy (RT), each playing unique roles in oncology care. One significant aspect is RT, guided by radiation oncologists (ROs). This paper serves as a detailed primer for non-oncologists, medical students, or non-clinical investigators, educating them on contemporary RT practices. Methods: This report follows the process of RT planning and execution. Starting from the decision-making in multidisciplinary teams to the completion of RT and subsequent patient follow-up, it aims to offer non-oncologists an understanding of the RO's work in a comprehensive manner. Results: The first step in RT is a planning session that includes obtaining a CT scan of the area to be treated, known as the CT simulation. The patients are imaged in the exact position in which they will receive treatment. The second step, which is the primary source of uncertainty, involves the delineation of treatment targets and organs at risk (OAR). The objective is to ensure precise irradiation of the target volume while sparing the OARs as much as possible. Various radiation modalities, such as external beam therapy with electrons, photons, or particles (including protons and carbon ions), as well as brachytherapy, are utilized. Within these modalities, several techniques, such as three-dimensional conformal RT, intensity-modulated RT, volumetric modulated arc therapy, scattering beam proton therapy, and intensity-modulated proton therapy, are employed to achieve optimal treatment outcomes. The RT plan development is an iterative process involving medical physicists, dosimetrists, and ROs. The complexity and time required vary, ranging from an hour to a week. Once approved, RT begins, with image-guided RT being standard practice for patient alignment. The RO manages acute toxicities during treatment and prepares a summary upon completion. There is a considerable variance in practices, with some ROs offering lifelong follow-up and managing potential late effects of treatment. Conclusions: Comprehension of RT clinical effects by non-oncologists providers significantly elevates long-term patient care quality. Hence, educating non-oncologists enhances care for RT patients, underlining this report's importance.

Particle radiotherapy for breast cancer

Breast cancer is the most common malignant tumor in female patients. Along with surgery, radiotherapy is one of the most commonly prescribed treatments for breast cancer. Over the past few decades, breast cancer radiotherapy technology has significantly improved. Nevertheless, related posttherapy complications should not be overlooked. Common complications include dose-related coronary toxicity, radiation pneumonia, and the risk of second primary cancer of the contralateral breast. Particle radiotherapy with protons or carbon ions is widely attracting interest as a potential competitor to conventional photon radiotherapy because of its superior physical and biological characteristics. This article summarizes the results of clinical research on proton and carbon-ion radiotherapy for treating breast cancer.

Post-Neoadjuvant Treatment Strategies for Patients with Early Breast Cancer

Simple Summary

Treatment strategies for early breast cancer have significantly improved in the last decades. Several new effective agents have proved clinical benefit and have entered the clinics, changing the treatment landscape for this disease and inducing significant prolongation of patient survival. Alongside, there has been an evolution in the design of clinical trials for early breast cancer, with an increasing interest in the pre-surgical treatment approach, which allows a direct evaluation of treatment effect on tumor size and a post-therapy risk stratification. Consequently, the post-neoadjuvant setting has been gaining increasing attention, thanks to the possibility to provide additional treatment for selected patients at higher risk of relapse, namely those who did not respond to neoadjuvant therapy and had residual disease at surgery.

Abstract

Pre-surgical treatments in patients with early breast cancer allows a direct estimation of treatment efficacy, by comparing the tumor and the treatment. Patients who achieve a pathological complete response at surgery have a better prognosis, with lower risk of disease recurrence and death. Hence, clinical research efforts have been focusing on high-risk patients with residual disease at surgery, who may be “salvaged” through additional treatments administered in the post-neoadjuvant setting. In the present review, we aim to illustrate the development and advantages of the post-neoadjuvant setting, and to discuss the available strategies for patients with early breast cancer, either approved or under investigation. This review was written after literature search on main scientific databases (e.g., PubMed) and conference proceedings from major oncology conferences up to 1 August 2022. T-DM1 and capecitabine are currently approved as post-neoadjuvant treatments for patients with HER2-positive and triple-negative breast cancer, respectively, with residual disease at surgery. More recently, other treatment strategies have been approved for patients with high-risk early breast cancer, including the immune checkpoint inhibitor pembrolizumab, the PARP inhibitor olaparib and the CDK 4/6 inhibitor abemaciclib. Novel agents and treatment combinations are currently under investigation as promising post-neoadjuvant treatment strategies.

Effect of postmastectomy radiotherapy on pT1-2N1 breast cancer patients with different molecular subtypes: A real-world study based on the inverse probability of treatment weighting method

To investigate the significance of postmastectomy radiotherapy (PMRT) for different molecular subtypes of female breast cancer T1-2N1M0 based on inverse probability of treatment weighting (IPTW). The data of breast cancer patients diagnosed between 2010 and 2014 from the Surveillance, Epidemiology, and End Results (SEER) database were extracted. According to the status of hormone receptor (HR) and human epidermal growth factor receptor-2 (HER2), the patients were classified into luminal-A (HR+/HER2-), luminal-B (HR+/HER2+), HER2-enriched (HR-/HER2+), and TNBC (HR-/HER2-) subtypes. The association between radiation therapy and breast cancer-specific survival (BCSS) and Overall survival (OS) was retrospectively analyzed. Inverse probability of treatment weighting (IPTW) was applied to balance measurable confounders. Among the 16 894 patients, 6 055 (35.8%) were in the PMRT group and 10 839 (64.2%) were in the nonPMRT group, with a median follow-up of 48 months. There were 1003 deaths from breast cancer and 754 deaths from other causes. After IPTW, the covariates between groups reached complete equilibrium, the multifactorial Cox regression analysis showed that PMRT significantly prolonged OS and BCSS in Luminal-A and TNBC subtype breast cancer patients, yet it brought little significant survival advantage in Luminal-B and HER2-enriched subtype patients. Our study demonstrates a beneficial impact for PMRT on OS and BCSS among Luminal-A and TNBC subtype breast cancer patients with T1-2N1 disease.

HLX11, a Proposed Pertuzumab Biosimilar: Pharmacokinetics, Immunogenicity, and Safety Profiles Compared to Three Reference Biologic Products (US-, EU-, and CN-Approved Pertuzumab) Administered to Healthy Male Subjects

Background

Pertuzumab is a humanized monoclonal antibody for the treatment of breast cancer. HLX11 is a biosimilar of pertuzumab developed by Shanghai Henlius Biotech, Inc. We conducted a bioequivalence study for HLX11 and pertuzumab (United States [US]-, European Union [EU]-, and China [CN]-approved products).

Objectives

This study compared the biosimilarity in pharmacokinetics (PK), safety, and immunogenicity between HLX11 and reference pertuzumab (approved in the US, the EU, and CN) in healthy Chinese male participants after a single infusion and further characterized the PK profile of HLX11.

Methods

Eligible individuals were randomized 1:1:1:1 to receive a single dose of 420 mg HLX11, US-, EU-, or CN-pertuzumab via intravenous infusion over 60 min. The primary endpoints were maximum serum drug concentration (C_max), area under the serum concentration–time curve (AUC) from time 0 to time of the last quantifiable concentration (AUC_0–t), and AUC from time 0 to infinity (AUC_0–∞). PK bioequivalence was established if the 90% confidence intervals (CIs) of the geometric mean ratios of the primary endpoints were between 80.0 and 125.0%. Secondary endpoints included other PK parameters, safety, and immunogenicity.

Results

A total of 160 participants were enrolled and randomly assigned to each group (n = 40 per group). The 90% CIs of the geometric mean ratios of the primary endpoints were all within the prespecified equivalence margins (HLX11 vs. pertuzumab [US-, EU-, CN-approved products]: C_max 97.03–115.06%, 91.39–109.80%, 94.53–110.65%; AUC_0–t 87.65–99.68%, 87.07–100.79%, 86.29–101.09%; AUC_0–∞ 87.66–99.90%, 87.54–101.05%, 89.23–103.20%). The incidence of adverse drug reactions was comparable across the four groups. The presence of anti-drug antibodies or neutralizing antibodies had no obvious effect on PK.

Conclusion

The PK, safety, and immunogenicity of HLX11 were highly similar to those of reference pertuzumab (US-, EU-, CN-approved products). The established bioequivalence supports further clinical trials of HLX11 in cancer treatment.

Trial Registration

This study was registered with ClinicalTrials.gov (NCT04411550) and Chinadrugtrials.org.cn (CTR20200618).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40259-022-00534-w.

Stereotactic Radiation and Dual Human Epidermal Growth Factor Receptor 2 Blockade with Trastuzumab and Pertuzumab in the Treatment of Breast Cancer Brain Metastases: A Single Institution Series

(1) Background: This study aims to assess the safety and efficacy of fractionated SRT (fSRT) and pertuzumab-trastuzumab (PT) in patients with breast cancer brain metastases (BCBM). (2) Methods: Patients with HER2+ BCBM who received FSRT from 2015 to 2019 were identified. Patients were included if they were treated with fSRT within 21 days of receiving PT. All lesions were treated with LINAC-based fSRT to a total dose of 27 Gy delivered in three consecutive fractions. All patients received concurrent PT. Patients were evaluated 4-6 weeks after SRS and subsequently every 2-3 months with MRI re-imaging (3) Results: A total of 49 patients with HER2+ brain metastases were identified. Of these patients, a total of 10 patients with 32 HER2+ BCBM were treated with concurrent SRT and PT and included in the analysis. No local progression was observed. Overall response rate was 68.7%. Only one patient developed asymptomatic radionecrosis. Median time to BM occurrence was 15.6 (range: 1-40.5 months). Distant intracranial failure occurred in 4/10 patients (40.0%). Overall BCBM median survival was 33.9 months (95%CI 24.1-43.6). Mean duration of PT treatment was 27.9 months (range: 10.1-53.7 months). (4) Conclusions: In our single institution experience, fSRT and PT showed to be a safe treatment for patients with BCBM with an adequate overall response rate.