Exploring the clinical outcomes and safety profile of inetetamab treatment in metastatic breast cancer patients: A multicenter assessment of a Chinese-origin recombinant Anti-HER2 monoclonal antibody.

BACKGROUND: Inetetamab is a novel recombinant humanized anti-HER2 monoclonal antibody. This study aimed to evaluate the efficacy and safety of inetetamab and predictive factors for response in HER2-positive metastatic breast cancer (MBC) patients. METHODS: A cohort of HER2-positive MBC patients who received inetetamab-based therapy between June 2020 and August 2021 was evaluated. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included objective response rate (ORR) and disease control rate (DCR). Adverse events (AEs) were graded according to the National Cancer Institute Common Toxicity Criteria. RESULTS: A total of 141 patients were included in the final analysis. The median PFS of the entire cohort was 7.1 months. The median number of treatment lines administered was three. The ORR was 36.9 %, and the DCR was 80.9 %. The most frequently employed treatment strategy was inetetamab + chemotherapy (49/141, 34.8 %), followed by inetetamab + HER2-tyrosine kinase inhibitors (HER2-TKIs) + chemotherapy, inetetamab + pertuzumab + chemotherapy, inetetamab + endocrine treatment and inetetamab + HER2-TKIs. Cox multivariate analysis revealed that PFS was associated with liver metastasis (hazard ratio [HR] 2.112, 95 % confidence interval [CI] 1.334-3.343, p = 0.001), previous HER2-TKI treatment (HR 2.019, 95 % CI 1.133-3.597, p = 0.017) and estrogen receptor positivity (HR 0.587, 95 % CI 0.370-0.934, p = 0.024). The toxicity was tolerable, with neutropenia being the most common treatment-related grade 3/4 AE (14.9 %). CONCLUSION: Inetetamab demonstrates effectiveness with a manageable safety profile, offering a promising therapeutic option for HER2-positive breast cancer patients who have shown resistance to prior anti-HER2 treatments.

Breast cancer metastases to the thyroid and stomach: A case report.

The most common sites of metastasis for breast cancer are the soft tissues, bones, lungs, liver and brain; however, metastases to the gastrointestinal tract and thyroid gland from breast cancer rarely occur. The present study describes the case of a 30-year-old woman who developed gastric and thyroid metastases 5 years after her initial diagnosis of invasive ductal breast carcinoma. The initial pathological diagnosis when receiving modified radical mastectomy was invasive ductal carcinoma, and further immunohistochemical examination revealed the cancer to be estrogen receptor (-), progesterone receptor (-), human epidermal growth factor receptor 2 (HER2; ++) and Ki-67 (70%). Genetic testing indicated the HER2 amplification mutation, whereas BRCA1/2 testing was negative. A total of 21 months after surgery, during regular follow-up, the patient was revealed to have developed an enlarged lymph node in the left side of the neck and the first recurrence was confirmed. Approximately 5 years after surgery, the patient gradually developed multi-site metastasis, and developed metastases to the thyroid gland and stomach confirmed by pathology and imaging. Combined chemotherapy and targeted therapy were administered and exhibited good efficacy; however, the patient subsequently died due to heart failure. This case report describes the occurrence of gastric and thyroid metastases from breast cancer, and highlights the importance of distinguishing between metastatic and primary tumors. Distinguishing between a metastatic and primary tumor is crucial as treatment protocols vary significantly for these two types of tumors. For patients with a history of breast cancer it should first be considered whether they have metastasis of the primary disease or discomfort caused by treatment; however, the possibility of a second primary tumor cannot be ignored. If the patient has symptoms such as loss of appetite, nausea, vomiting, stomach pain and stomach discomfort, a gastroscopy should be performed in a timely manner.

Overexpressed SIRT6 ameliorates doxorubicin-induced cardiotoxicity and potentiates the therapeutic efficacy through metabolic remodeling.

Since the utilization of anthracyclines in cancer therapy, severe cardiotoxicity has become a major obstacle. The major challenge in treating cancer patients with anthracyclines is minimizing cardiotoxicity without compromising antitumor efficacy. Herein, histone deacetylase SIRT6 expression was reduced in plasma of patients treated with anthracyclines-based chemotherapy regimens. Furthermore, overexpression of SIRT6 alleviated doxorubicin-induced cytotoxicity in cardiomyocytes, and potentiated cytotoxicity of doxorubicin in multiple cancer cell lines. Moreover, SIRT6 overexpression ameliorated doxorubicin-induced cardiotoxicity and potentiated antitumor efficacy of doxorubicin in mice, suggesting that SIRT6 overexpression could be an adjunctive therapeutic strategy during doxorubicin treatment. Mechanistically, doxorubicin-impaired mitochondria led to decreased mitochondrial respiration and ATP production. And SIRT6 enhanced mitochondrial biogenesis and mitophagy by deacetylating and inhibiting Sgk1. Thus, SIRT6 overexpression coordinated metabolic remodeling from glycolysis to mitochondrial respiration during doxorubicin treatment, which was more conducive to cardiomyocyte metabolism, thus protecting cardiomyocytes but not cancer cells against doxorubicin-induced energy deficiency. In addition, ellagic acid, a natural compound that activates SIRT6, alleviated doxorubicin-induced cardiotoxicity and enhanced doxorubicin-mediated tumor regression in tumor-bearing mice. These findings provide a preclinical rationale for preventing cardiotoxicity by activating SIRT6 in cancer patients undergoing chemotherapy, but also advancing the understanding of the crucial role of SIRT6 in mitochondrial homeostasis.

Pyrotinib in combination with letrozole for hormone receptor-positive, human epidermal growth factor receptor 2-positive metastatic breast cancer (PLEHERM): a multicenter, single-arm, phase II trial.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2) targeted therapy combined with endocrine therapy has been recommended as an alternative treatment strategy for patients with hormone receptor (HR)-positive, HER2-positive metastatic breast cancer (MBC). This study aimed to evaluate the role of pyrotinib, an oral pan-HER irreversible tyrosine kinase inhibitor, in combination with letrozole for patients with HR-positive, HER2-positive MBC. METHODS: In this multi-center, phase II trial, HR-positive and HER2-positive MBC patients who were not previously treated for metastasis disease were enrolled. Patients received daily oral pyrotinib 400 mg and letrozole 2.5 mg until disease progression, unacceptable toxicity, or withdrawal of consent. The primary endpoint was the clinical benefit rate (CBR) assessed by an investigator according to the Response Evaluation Criteria in Solid Tumors version 1.1. RESULTS: From November 2019 to December 2021, 53 patients were enrolled and received pyrotinib plus letrozole. As of August 2022, the median follow-up duration was 11.6 months (95% confidence interval [CI], 8.7-14.0 months). The CBR was 71.7% (95% CI, 57.7-83.2%), and the objective response rate was 64.2% (95% CI, 49.8-76.9%). The median progression-free survival was 13.7 months (95% CI, 10.7-18.7 months). The most common treatment-related adverse event of grade 3 or higher was diarrhea (18.9%). No treatment-related deaths were reported, and one patient experienced treatment discontinuation due to adverse event. CONCLUSIONS: Our preliminary results suggested that pyrotinib plus letrozole is feasible for the first-line treatment of patients with HR-positive and HER2-positive MBC, with manageable toxicities. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04407988.

Circulating tumor DNA profile and its clinical significance in patients with hormone receptor-positive and HER2-negative mBC.

Background: After early-line (first- and second-line) endocrine therapy, hormone-receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancers (mBCs) become resistant to endocrine therapy. Genetic alterations may underlie resistance to endocrine therapies. This study aims to investigate the circulating tumor DNA (ctDNA) alterations and the clinical implication in hormone-receptor-positive, HER2-negative metastatic breast cancer patients with multiline endocrine therapy failure. Methods: This registered study (NCT05079074, ClinicalTrials.gov) enrolled 104 patients with hormone-receptor-positive, HER2-negative metastatic breast cancer who progressed after the early-line endocrine therapy. ctDNA alterations were analyzed by next generation sequencing (NGS). ctDNA alterations were ranked and clustered by using R 'ComplexHeatmap' and 'hclust' function. ctDNA-guided therapy was administrated. Progression-free survival (PFS) was assessed COX regression analysis, and Kaplan-Meier curves were plotted. Findings: The top ctDNA altered genes were TP53 (39%), PIK3CA (38%), BRCA1/2 (13%), ESR1 (12%), FGFR (11%), ERBB2 (11%), and GATA3 (9%). Among these genes, TP53, PIK3CA helix domain mutation (PIK3CA-HD), FGFR, ESR1 and GATA3 were related to endocrine therapy resistance. The genetic landscapes changed and tumor mutation burden increased in both TP53-altered and PIK3CA-altered patients. Both BRCA1/2 and ERBB2 alterations correlated with TP53 alterations (P=0.02 and P=0.04, respectively). However, while 93% BRCA1/2 alterations concentrated in PIK3CA-wildtype patients, 82% ERBB2 alterations concentrated in PIK3CA-altered patients. Kaplan-Meier curves showed that patients who received druggable ctDNA alteration-guided treatment (DDAT) had significantly longer PFS than those who received physician-chosen therapy, with median PFS of 6.1 months versus 4.6 months (hazard ratio = 0.53, 95% CI: 0.34-0.85, Logrank P = 0.006). Conclusion: Multiple genetic alterations were important reasons for the failure of endocrine therapy for HR-positive and HER2-negative mBC. Targeting these genes might restore the treatment sensitivity and benefit survival.

Clinical value of next-generation sequencing in guiding decisions regarding endocrine therapy for advanced HR-positive/HER-2-negative breast cancer.

Objective: The mechanism of acquired gene mutation plays a major role in resistance to endocrine therapy in hormone receptor (HR)-positive advanced breast cancer. Circulating tumor DNA (ctDNA) has been allowed for the assessment of the genomic profiles of patients with advanced cancer. We performed this study to search for molecular markers of endocrine therapy efficacy and to explore the clinical value of ctDNA to guide precise endocrine therapy for HR-positive/human epidermal growth factor receptor-2 (HER-2)-negative metastatic breast cancer patients. Methods: In this open-label, multicohort, prospective study, patients were assigned to four parallel cohorts and matched according to mutations identified in ctDNA: 1) activation of the phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway preferred mTOR inhibitor combined with endocrine therapy; 2) estrogen receptor 1 (ESR1) mutation preferred fulvestrant; 3) HER-2 mutations preferred pyrotinib; and 4) no actionable mutations received treatment according to the clinical situation. In all cohorts, patients were divided into compliance group and violation group. The primary outcome measure was progression-free survival (PFS), and the secondary outcome measure was overall survival (OS). Results: In all cohorts, the combined median PFS was 4.9 months, and median PFS for the compliance and violation groups was 6.0 and 3.0 months, respectively [P=0.022, hazard ratio (HR)=0.57]. Multivariate Cox regression model showed the risk of disease progression was lower in compliance group than in violation group (P=0.023, HR=0.55). Among the patients with HER-2 mutations, the median PFS was 11.1 months in the compliance group and 2.2 months in the violation group (P=0.011, HR=0.20). There was no significant difference in the median PFS between patients who did and did not comply with the treatment protocol in patients with activation of the PI3K/AKT/mTOR or ESR1 mutation. Conclusions: The results suggest that ctDNA may help to guide the optimal endocrine therapy strategy for metastatic breast cancer patients and to achieve a better PFS. Next-generation sequencing (NGS) detection could aid in distinguishing patients with HER-2 mutation and developing new treatment strategies.

The circulating tumor DNA (ctDNA) alteration level predicts therapeutic response in metastatic breast cancer: Novel prognostic indexes based on ctDNA.

PURPOSE: Circulating tumor DNA (ctDNA) has good clinical guiding value for metastatic breast cancer (MBC) patients. This study aimed to apply a novel genetic analysis approach for therapeutic prediction based on ctDNA alterations. METHOD: This nonrandomized, multicenter study recruited 223 MBC patients (NCT05079074). Plasma samples were collected for target-capture deep sequencing of ctDNA at baseline, after the 2nd cycle of treatment, and when progressive disease (PD) was evaluated. Samples were categorized into four levels according to the number of ctDNA alterations: level 1 (no alterations), level 2 (1-2 alterations), level 3 (3-4 alterations) and level 4 (≥5 alterations). According to ctDNA alteration level and variant allele frequency (VAF), a novel ctDNA-level Response Evaluation Criterion in Solid Tumors (ctle-RECIST) was established to assess treatment response and predict progression-free survival (PFS). RESULTS: The median PFS in level 1 (6.63 months) patients was significantly longer than that in level 2-4 patients (level 2: 5.70 months; level 3-4: 4.90 months, p < 0.05). After 2 cycles of treatment, based on ctle-RECIST, the median PFS of level-based disease control rate (lev-DCR) patients was significantly longer than that of level-based PD (lev-PD) patients [HR 2.42 (1.52-3.85), p < 0.001]. In addition, we found that ctDNA level assessment could be a good supplement to radiologic assessment. The median PFS in the dual-DCR group tended to be longer than that in the single-DCR group [HR 1.41 (0.93-2.13), p = 0.107]. CONCLUSION: The ctDNA alteration level and ctle-RECIST could be novel biomarkers of prognosis and could complement radiologic assessment in MBC.

Subtyping of metastatic breast cancer based on plasma circulating tumor DNA alterations: An observational, multicentre platform study.

Background: After multiple lines of therapies, no guideline or consensus is currently available for the treatment of patients with metastatic breast cancer. This study aims to evaluate the efficacy of a novel re-subtyping and treatment strategy based on ctDNA alterations. Methods: This observational, multicentre study recruited 223 patients with metastatic breast cancer intending to receive late-line therapy from Dec 1, 2016, to June 31, 2019. This study took place in Hunan Cancer Hospital, the Forth Hospital of Changsha and Zhuzhou Central Hospital in China. ctDNA alterations were assessed by next-generation sequencing (NGS). Patients with druggable ctDNA alterations were treated with corresponding targeted drugs which are clinically available. Other patients received physician-chosen treatment. This study was registered with ClinicalTrials.gov, NCT05079074. Findings: The progression-free survival (hazard ratio: 0.45, 95% Confidence Interval (CI): 0.33-0.62, P < 0.0001) and disease control rate (89.4% vs. 65.9%, P < 0.0001) were significantly improved in patients who received druggable ctDNA alteration-guided therapy compared with those of patients who received physician-chosen treatment. ctDNA alterations with top rank and high clustering scores were classified into four subtypes based on their functions as follows: 1) extracellular function (ECF), 2) cell proliferation (CP), 3) nuclear function (NF), and 4) cascade signaling pathway (CSP). A significant benefit from ctDNA alteration-guided treatment was observed in patients with NF and CSP ctDNA alterations, with hazard ratios of 0.39 (95% CI: 0.24-0.65, P = 0.0003) and 0.14 (95% CI: 0.04-0.46, P < 0.0001), respectively. Interpretation: After multiline traditional pathological HR/HER2 subtype-guided therapies, ctDNA testing could identify druggable ctDNA alterations to guide late-line therapy for patients with metastatic breast cancer. Funding: This work was supported by Key Grants of Research and Development in Hunan Province (2018SK2124, 2018SK2120), Natural Science Foundation of Hunan (2019JJ50360), Hunan Provincial Health Commission Project (B2019085, B2019089 and C2019070), and Changsha Science and Technology Project (kq2004125 and kq2004137).

Molecular landscape of TP53 mutations in breast cancer and their utility for predicting the response to HER-targeted therapy in HER2 amplification-positive and HER2 mutation-positive amplification-negative patients.

PURPOSE: We used targeted capture sequencing to analyze TP53-mutated circulating tumor DNA (ctDNA) in metastatic breast cancer patients and to determine whether TP53 mutation has predictive value for anti-human epidermal growth factor receptor 2 (HER2) treatment for in HER2 amplification-positive patients (HER2+) and HER2 mutation-positive, amplification-negative (HER2-/mut) patients. PATIENTS AND METHODS: TP53 mutation features were analyzed in the Geneplus cohort (n = 1184). The MSK-BREAST cohort was used to explore the value of TP53 mutation in predicting anti-HER-2 antibody efficacy. Sequencing of ctDNA in phase Ib, phase Ic, phase II clinical trials of pyrotinib (HER2+ patients), and an investigator-initiated phase II study of pyrotinib (HER2-/mut patients) were performed to analyze the relationships between TP53 mutation and prognosis for HER2 TKIs. The MSK-BREAST cohort, MutHER, and SUMMIT cohort were used for verification. RESULTS: TP53 mutations were detected in 53.1% (629/1184) of patients in the Geneplus cohort. The TP53 mutation rate was higher in HR-negative (p < 0.001) and HER2 amplification-positive (p = 0.015) patients. Among patients receiving anti-HER2 antibody therapy, those whose tumors carried TP53 mutations had a shorter PFS (p = 0.004). However, the value of TP53 mutation in predicting HER2 TKI response was inconsistent. In HER2+ patients, no difference in PFS was observed among patients with different TP53 statuses in the combined analysis of the pyrotinib phase Ib, phase Ic, and phase II clinical trials (p = 1.00) or in the MSK-BREAST cohort (p = 0.62). In HER2-/mut patients, TP53 mutation-positive patients exhibited a trend toward worse prognosis with anti-HER2 TKI treatment than TP53-wild-type patients in our investigator-initiated phase II study (p = 0.15), and this trend was confirmed in the combined analysis of the MutHER and SUMMIT cohorts (p = 0.01). CONCLUSIONS: TP53 mutation can be used to identify biomarkers of anti-HER2 antibody drug resistance in HER2+ patients and HER2 TKI resistance in HER2-/mut patients.

Clinical and genetic predictions of early-onset cardiac toxicity in adjuvant chemotherapy for breast cancer.

Aim: To identify clinical and genetic variants associated with early-onset cardiac toxicity with a low cumulative dose of chemotherapy drugs in breast cancer. Methods: A total of 388 recruited patients completed routine blood, liver and kidney function, D-dimer, troponin T, brain natriuretic peptide (BNP) or N-terminal prohormone of BNP, ECG and echocardiography tests before and after adjuvant chemotherapy. 25 single-nucleotide polymorphisms (SNPs) were tested. Results: A total of 277 adjuvant chemotherapy-related cardiac toxicity events were recorded in 180 patients (46.4%). Anthracycline-containing chemotherapy (odds ratio: 1.848; 95% CI: 1.135-3.008; p = 0.014) and the SLC28A3 rs885004 GG genotype (odds ratio: 2.034; 95% CI: 1.189-3.479; p = 0.010) were found to be associated with overall cardiac toxicity. The final predictive risk model consisting of clinical risk factors and SNPs was better than SNP alone (p = 0.006) or clinical risk factor alone (p = 0.065). Conclusion: On the basis of clinical factors, a prediction model with genetic susceptibility factors can better predict early-onset cardiac toxicity.

Antibody-drug conjugates in HER2-positive breast cancer.

ABSTRACT: Antibody-drug conjugates (ADCs) combine the high specificity of monoclonal antibodies with the high anti-tumor activity of small molecular cytotoxic payloads. The anti-tumor activity of ADCs is mainly achieved by the direct blocking of the receptor by monoclonal antibodies, direct action and bystander effect of cytotoxic drugs, and antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. ADCs have been used in adjuvant therapy and rescue treatment of human epidermal receptor 2 (HER2)-positive breast cancer, greatly improving the prognosis of breast cancer patients. Several ongoing clinical trials of ADC for breast cancer and other solid tumors proved the potential of ADCs will provide more promising treatment options for patients with malignant tumors. This review introduces the mechanism and latest clinical progress of ADC drugs approved for HER2-positive breast cancer to guide clinical practice and conduct research.

The molecular tumor burden index as a response evaluation criterion in breast cancer.

Circulating tumor DNA (ctDNA) is a potential biomarker of prognosis and therapeutic response. We conducted this study to explore the role of the molecular tumor burden index (mTBI) in ctDNA as a therapeutic response and prognostic biomarker in a larger cohort prospective phase III randomized multicenter study. We collected 291 plasma samples from 125 metastatic breast cancer patients from the CAMELLIA study (NCT01917279). Target-capture deep sequencing of 1021 genes was performed to detect somatic variants in ctDNA from the plasma samples. The pretreatment mTBI value was correlated with tumor burden (P = 0.025). Patients with high-level pretreatment mTBI had shorter overall survival than patients with low-level pretreatment mTBI, and the median overall survival was 40.9 months and 68.4 months, respectively (P = 0.011). Patients with mTBI decrease to less than 0.02% at the first tumor evaluation had longer progression-free survival and overall survival (P < 0.001 and P = 0.007, respectively). The mTBI has good sensitivity to identify complete response/partial response and progressive disease based on computed tomography scans (88.5% and 87.5%, respectively). The patients classified as molecular responders had longer progression-free survival and overall survival than the nonmolecular responders in the overall cohort (P < 0.001 and P = 0.036, respectively), as well as in the cohort in which computed tomography scans were defined as representing stable disease (P = 0.027 and P = 0.015, respectively). The mTBI in ctDNA detected in liquid biopsies is a potential biomarker of therapeutic response and prognosis in patients with metastatic breast cancer.

Epithelial-Mesenchymal-Transition-Like Circulating Tumor Cell-Associated White Blood Cell Clusters as a Prognostic Biomarker in HR-Positive/HER2-Negative Metastatic Breast Cancer.

BACKGROUND: Although positive Circulating tumor cells (CTCs) status has been validated as a prognostic marker in breast cancer, the interaction between immune cells and CTCs during the progress of Epithelial-mesenchymal-transition (EMT), and the clinical implications of CTC-associated white blood cell clusters (CTC-WBC clusters) for metastatic breast cancer are largely uncharacterized. METHODS: We optimized a filter-based method combined with an RNA in situ hybridization technique according to the epithelial- and mesenchymal-markers to analyze EMT in CTC-WBC clusters. Serial peripheral blood samples from 135 patients with Hormone receptor (HR)-positive/HER2-negative metastatic breast cancer receiving first-line chemotherapy with docetaxel plus capecitabine were prospectively collected until disease progression from Nov 2013 to March 2019. Follow-up data collection was conducted until July 2020. RESULTS: A total of 452 blood samples at all time-points were collected and analyzed. Median age of the cohort was 51.0 years (range, 27 to 73 years), and most of them (76.3%) had visceral metastases. Median progression-free survival (PFS) was 10.6 months (95% CI, 8.8 to 12.3 months). The presence of EMT-like CTC-WBC clusters was more frequently evident among patients with simultaneous bone and lymph node metastases (87.5% vs 36.2%, P=0.006), whereas no associations were observed between CTC-WBC clusters and other clinicopathologic characteristics before chemotherapy. The patients with EMT-like CTC-WBC clusters tended to show a significantly increased number of total CTC count (median,19.0 vs 5.0, P<0.001). The patients with at least one detectable EMT-like CTC-WBC cluster at baseline were characterized by significantly worse PFS, when compared to the patients with no EMT-like CTC-WBC clusters detected (7.0 vs 10.7 months, P=0.023), and those with five or more epithelial-based CTCs detected per 5mL of peripheral blood (7.0 vs 12.7 months, P=0.014). However, the total CTC-WBC clusters were not correlated with patients' survival in the cohort (8.4 vs 10.6 months, P=0.561). CONCLUSIONS: Our data provide evidence that the emergence of CTC-WBC clusters underwent EMT before treatment is associated with significantly poorer PFS in HR-positive/HER2-negative metastatic breast cancer patients receiving docetaxel plus capecitabine, which may be used as a parameter to predict the clinical outcomes and a potential target for individualized therapy.

Development and Validation of a New Clinical Prediction Model of Catheter-Related Thrombosis Based on Vascular Ultrasound Diagnosis in Cancer Patients.

Background: Central venous catheters are convenient for drug delivery and improved comfort for cancer patients, but they also cause serious complications. The most common complication is catheter-related thrombosis (CRT). Objectives: This study aimed to evaluate the incidence and risk factors for CRT in cancer patients and develop an effective prediction model for CRT in cancer patients. Methods: The development of our prediction model was based on a retrospective cohort (n = 3,131) from the National Cancer Center. Our prediction model was confirmed in a prospective cohort from the National Cancer Center (n = 685) and a retrospective cohort from the Hunan Cancer Hospital (n = 61). The predictive accuracy and discriminative ability were determined by receiver operating characteristic (ROC) curves and calibration plots. Results: Multivariate analysis demonstrated that sex, cancer type, catheter type, position of the catheter tip, chemotherapy status, and antiplatelet/anticoagulation status at baseline were independent risk factors for CRT. The area under the ROC curve of our prediction model was 0.741 (CI: 0.715-0.766) in the primary cohort and 0.754 (CI: 0.704-0.803) and 0.658 (CI: 0.470-0.845) in validation cohorts 1 and 2, respectively. The model also showed good calibration and clinical impact in the primary and validation cohorts. Conclusions: Our model is a novel prediction tool for CRT risk that accurately assigns cancer patients into high- and low-risk groups. Our model will be valuable for clinicians when making decisions regarding thromboprophylaxis.

Molecular landscape and efficacy of HER2-targeted therapy in patients with HER2-mutated metastatic breast cancer.

Human epidermal growth factor receptor 2 (HER2) protein overexpression or gene amplification is an important predictive biomarker for identifying patients with breast cancer, who may benefit from HER2-targeted therapy. However, little is known about the molecular landscape and efficacy of HER2-targeted therapy in patients with HER2-mutated metastatic breast cancer. We analysed the HER2 mutation features of 1184 patients with invasive breast cancer. In addition, a single-arm, prospective, phase-II study (NCT03412383) of pyrotinib was conducted in patient with metastatic HER2 amplification-negative, mutation-positive breast cancer. Peripheral blood was collected from each patient and circulating tumour DNA (ctDNA) sequencing was performed using a 1021 gene panel. HER2 mutations were detected in 8.9% (105/1184) of patients. The HER2 amplification-positive patients had a higher mutation frequency than the HER2 amplification-negative patients (19.5% vs. 4.8%, P < 0.001). A multivariate Cox regression analysis indicated that patients with HER2 mutations had a shorter progression-free survival (PFS) than HER2 wild-type patients (median PFS 4.7 months vs. 11.0 months, hazard ratio 2.65, 95% confidence interval 1.25-5.65, P = 0.011). Ten HER2 amplification-negative, mutation-positive patients who received pyrotinib monotherapy were ultimately included in the efficacy analysis. The median PFS was 4.9 months. The objective response rate (complete response + partial response) was 40.0% and the clinical benefit rate (complete response + partial response + stable disease over 24 weeks) was 60%. In conclusion, a HER2 gene mutation analysis is potentially useful to identify biomarkers of trastuzumab resistance in HER2 amplification-positive patients. Patients with HER2-mutated, non-amplified metastatic breast cancers may benefit from pyrotinib.

Gut Microbiota Profiling in Patients With HER2-Negative Metastatic Breast Cancer Receiving Metronomic Chemotherapy of Capecitabine Compared to Those Under Conventional Dosage.

Purpose: Low-dose metronomic chemotherapy can achieve disease control with reduced toxicity compared to conventional chemotherapy in maximum tolerated dose. Characterizing the gut microbiota of cancer patients under different dosage regimens may describe a new role of gut microbiota associated with drug efficacy. Therefore, we evaluated the composition and the function of gut microbiome associated with metronomic capecitabine compared to conventional dosage. Methods: The fecal samples of HER2-negative metastatic breast cancer patients treated with capecitabine as maintenance chemotherapy were collected and analyzed by 16S ribosome RNA gene sequencing. Results: A total of 15 patients treated with metronomic capecitabine were compared to 16 patients under a conventional dose. The unweighted-unifrac index of the metronomic group was statistically significantly lower than that of the routine group (P = 0.025). Besides that, the Bray-Curtis distance-based redundancy analysis illustrated that the microbial genera between the two groups can be separated partly. Nine Kyoto Encyclopedia of Genes and Genomes (KEGG) modules were enriched in the metronomic group, while no KEGG modules were significantly enriched in the routine group. Moreover, univariate and multivariate analyses suggested that the median progression-free survival (PFS) was significantly shorter in patients with the gut microbial composition of Slackia (9.2 vs. 32.7 months, P = 0.004), while the patients with Blautia obeum had a significantly prolonged PFS than those without (32.7 vs. 12.9 months, P = 0.013). Conclusions: The proof-of-principle study suggested that the gut microbiota of patients receiving metronomic chemotherapy was different in terms of diversity, composition, and function from those under conventional chemotherapy, and the presence of specific bacterial species may act as microbial markers associated with drug resistance monitoring and prognostic evaluation.

Genome-wide chromosomal instability by cell-free DNA sequencing predicts survival in patients with metastatic breast cancer.

BACKGROUND: Genome-wide chromosomal instability, instead of specific somatic mutations or copy-number alterations in selected genes, is a significant property of cancer and may suggest a new strategy for treatment. Here we utilized cell-free DNA (cfDNA) sequencing to display the whole picture of chromosomal instability in patients with metastatic breast cancer (MBC), and evaluate its predictive value for patient survival. METHODS: The clinical data of 65 patients who had frozen plasma and planned to change the therapeutic regimen were retrospectively enrolled. Low-coverage whole-genome sequencing of cfDNA was performed to generate the chromosomal instability represented by chromosomal instability (CIN) score. RESULTS: Tumors with diverse status of hormone receptor and HER2 represented diverse chromosomal instability across the whole genome. According to the receiver operating characteristic curve and the statistical distribution, CIN score exceed 3881 was defined as "High". 32 (53.3%) patients with high CIN score had similar clinicopathologic characteristics compared with low CIN score patients. The median overall survival of patients with high CIN score was 21.2 months (95% CI 14.1-28.3), which was significantly inferior to those with low CIN score (not reached, P = 0.006). Regardless of various treatment regimens, the median progression free survival in patients with high CIN score was 7.3 months, which was significantly worse than those in the low CIN score population (11.0 months, P = 0.034). Multivariate analysis revealed that CIN score was an independent prognostic factor, with hazard ratio of 3.563 (P = 0.005). CONCLUSIONS: To our knowledge, this is the first study illustrating the prognostic value of chromosomal instability derived from cfDNA in MBC.