Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer: American Society of Clinical Oncology/College of American Pathologists Clinical Practice Guideline Focused Update

MRPL13 is a metastatic and prognostic marker of breast cancer: A silico analysis accompanied with experimental validation

BACKGROUND

Although progress has been made in accurate diagnosis and targeted treatments, breast cancer (BC) patients with metastasis still present a grim prognosis. With the continuous emergence and development of new personalized and precision medicine targeting specific tumor biomarkers, there is an urgent need to find new metastatic and prognostic biomarkers for BC patients.

METHODS

We were dedicated to identifying genes linked to metastasis and prognosis in breast cancer through a combination of in silico analysis and experimental validation.

RESULTS

A total of 25 overlap differentially expressed genes were identified. Ten hub genes (namely MRPL13, CTR9, TCEB1, RPLP0, TIMM8B, METTL1, GOLT1B, PLK2, PARL and MANBA) were identified and confirmed. MRPL13, TCEB1 and GOLT1B were shown to be associated with the worse overall survival (OS) and were optionally chosen for further verification by western blot. Only MRPL13 was found associated with cell invasion, and the expression of MRPL13 in metastatic BC was significantly higher than in primary BC.

CONCLUSION

We proposed MRPL13 could be a potential novel biomarker for the metastasis and prognosis of breast cancer.

MRI-based machine learning radiomics for prediction of HER2 expression status in breast invasive ductal carcinoma

Background

Human epidermal growth factor receptor 2 (HER2) is a tumor biomarker with significant prognostic and therapeutic implications for invasive ductal breast carcinoma (IDC).

Objective

This study aimed to explore the effectiveness of a multisequence magnetic resonance imaging (MRI)-based machine learning radiomics model in classifying the expression status of HER2, including HER2-positive, HER2-low, and HER2 completely negative (HER2-zero), among patients with IDC.

Methods

A total of 402 female patients with IDC confirmed through surgical pathology were enrolled and subsequently divided into a training group (n = 250, center I) and a validation group (n = 152, center II). Radiomics features were extracted from the preoperative MRI. A simulated annealing algorithm was used for key feature selection. Two classification tasks were performed: task 1, the classification of HER2-positive vs. HER2-negative (HER2-low and HER2-zero), and task 2, the classification of HER2-low vs. HER2-zero. Logistic regression, random forest (RF), and support vector machine were conducted to establish radiomics models. The performance of the models was evaluated using the area under the curve (AUC) of the operating characteristics (ROC).

Results

In total, 4506 radiomics features were extracted from multisequence MRI. A radiomics model for prediction of expression state of HER2 was successfully developed. Among the three classification algorithms, RF achieved the highest performance in classifying HER2-positive from HER2-negative and HER2-low from HER2-zero, with AUC values of 0.777 and 0.731, respectively.

Conclusions

Machine learning-based MRI radiomics may aid in the non-invasive prediction of the different expression status of HER2 in IDC.

Utilizing multiclassifier radiomics analysis of ultrasound to predict high axillary lymph node tumour burden in node-positive breast cancer patients: a multicentre study

BACKGROUND

The tumor burden within the axillary lymph nodes (ALNs) constitutes a pivotal factor in breast cancer, serving as the primary determinant for treatment decisions and exhibiting a close correlation with prognosis.

OBJECTIVE

This study aimed to investigate the potential of ultrasound-based radiomics and clinical characteristics in non-invasively distinguishing between low tumor burden (1-2 positive nodes) and high tumor burden (more than 2 positive nodes) in patients with node-positive breast cancer.

METHODS

A total of 215 patients with node-positive breast cancer, who underwent preoperative ultrasound examinations, were enrolled in this study. Among these patients, 144 cases were allocated to the training set, 37 cases to the validation set, and 34 cases to the testing set. Postoperative histopathology was used to determine the status of ALN tumor burden. The region of interest for breast cancer was delineated on the ultrasound image. Nine models were developed to predict high ALN tumor burden, employing a combination of three feature screening methods and three machine learning classifiers. Ultimately, the optimal model was selected and tested on both the validation and testing sets. In addition, clinical characteristics were screened to develop a clinical model. Furthermore, Shapley additive explanations (SHAP) values were utilized to provide explanations for the machine learning model.

RESULTS

During the validation and testing sets, the models demonstrated area under the curve (AUC) values ranging from 0.577 to 0.733 and 0.583 to 0.719, and accuracies ranging from 64.9% to 75.7% and 64.7% to 70.6%, respectively. Ultimately, the Boruta_XGB model, comprising five radiomics features, was selected as the final model. The AUC values of this model for distinguishing low from high tumor burden were 0.828, 0.715, and 0.719 in the training, validation, and testing sets, respectively, demonstrating its superiority over the clinical model.

CONCLUSIONS

The developed radiomics models exhibited a significant level of predictive performance. The Boruta_XGB radiomics model outperformed other radiomics models in this study.

Computational pathology in the identification of HER2-low breast cancer: Opportunities and challenges

For the past 2 decades, pathologists have been accustomed to reporting the HER2 status of breast cancer as either positive or negative, based on HER2 IHC. Today, however, there is a clinical imperative to employ a 3-tier approach to interpreting HER2 IHC that can also identify tumours categorised as HER2-low. Meeting this need for a finer degree of discrimination may be challenging, and in this article, we consider the potential for the integration of computational approaches to support pathologists in achieving accurate and reproducible HER2 IHC scoring as well as outlining some of the practicalities involved.

The association of magnetic resonance imaging features with five molecular subtypes of breast cancer

Objective

To identify the association of magnetic resonance imaging (MRI) features with molecular subtypes of breast cancer (BC).

Materials and methods

A retrospective study was conducted on 112 invasive BC patients with preoperative breast MRI. The confirmed diagnosis and molecular subtypes of BC were based on the postoperative specimens. MRI features were collected by experienced radiologists. The association of MRI features of each subtype was compared to other molecular subtypes in univariate and multivariate logistic regression analyses.

Results

The proportions of luminal A, luminal B HER2-negative, luminal B HER2-positive, HER2-enriched, and triple-negative BC were 14.3 %, 52.7 %, 12.5 %, 10.7 %, and 9.8 %, respectively. Luminal A was associated with hypo-isointensityon T2-weighted images (OR=6.214, 95 % CI: 1.163-33.215) and non-restricted diffusion on DWI-ADC (OR=6.694, 95 % CI: 1.172-38.235). Luminal B HER2-negative was related to the presence of mass (OR=7.245, 95 % CI: 1.760-29.889) and slow/medium initial enhancement pattern (OR=3.654, 95 % CI: 1.588-8.407). There were no associations between MRI features and luminal B HER2-positive. HER2-enriched tended to present as non-mass enhancement lesions (OR=20.498, 95 % CI: 3.145-133.584) with fast uptake in the initial postcontrast phase (OR=9.788, 95 % CI: 1.689-56.740), and distortion (OR=11.471, 95 % CI: 2.250-58.493). Triple-negative were associated with unifocal (OR=7.877, 95 % CI: 1.180-52.589), hyperintensityon T2-weighted images (OR=14.496, 95 % CI: 1.303-161.328), rim-enhanced lesions (OR=18.706, 95 % CI: 1.915-182.764), and surrounding tissue edema (OR=5.768, 95 % CI: 1.040-31.987).

Conclusion

Each molecular subtype of BC has distinct features on breast MRI. These characteristics can serve as an adjunct to immunohistochemistry in diagnosing molecular subtypes, particularly in cases, where traditional methods yield equivocal results.

Receptor Discordance in Metastatic Breast Cancer; a review of clinical and genetic subtype alterations from primary to metastatic disease

PURPOSE

Receptor and subtype discordance between primary breast tumours and metastases is a frequently reported phenomenon. The aim of this article is to review the current evidence on receptor discordance in metastatic breast cancer and to explore the benefit of performing a repeat biopsy in this context.

METHODS

Searches were undertaken on PubMed and Clinicaltrials.gov for relevant publications and trials.

CONCLUSION

The current guidelines recommend offering to perform a biopsy of a metastatic lesion to evaluate receptor status. The choice of systemic therapy in metastatic disease is often based on the receptor status of the primary lesion. As therapeutic decision making is guided by subtype, biopsy of the metastatic lesion to determine receptor status may alter treatment. This article discusses discordance rates, the mechanisms of receptor discordance, the effect of discordance on treatment and survival outcomes, as well as highlighting some ongoing clinical trials in patients with metastatic breast cancer.

Therapeutic indications for antibody-drug conjugates estimated from HER2 and p53 expressions in endometrial carcinoma

OBJECTIVE

While human epidermal growth factor receptor 2 (HER2) is upregulated in endometrial carcinoma-especially in the p53 aberrant type- conventional anti-HER2 therapy is not typically used for this cancer type. Recently, HER2-targeted antibody-drug conjugates have shown antitumor effects against HER2 low-expressing cancers. Therefore, we analyzed the clinicopathological characteristics of HER2-positive endometrial carcinomas including those with low expression, as well as the prognostic significance of p53 and HER2 co-expression.

METHODS

Immunohistochemistry for HER2 and p53 was performed in 530 patients with endometrial carcinoma; 124 cases (23%) were HER2-positive.

RESULTS

Of the HER2-positive cases, >50% were 1+. A high prevalence of HER2 expression was observed in serous (64%), clear-cell (73%), and mixed (64%) carcinomas. Notably, 19% of endometrioid carcinomas were HER2-positive. HER2 positivity was significantly associated with age ≥60 years, high-grade histological subtype, deep myometrium invasion, stage III/IV, recurrence, and death. Univariate analysis showed that HER2-positive cases had reduced progression-free survival (PFS) (p = 0.007) and overall survival (OS) (p = 0.012). However, after adjusting for stage, HER2 positivity was not associated with survival. In the early stage, co-expression of HER2-positive and p53 aberrant types was associated with shorter PFS (p < 0.001) and OS (p < 0.001) compared with at least one negative result. Multivariate analysis of PFS showed HER2 and p53 co-expression (hazard ratio, 1.891; 95% confidence interval, 1.183-5.971, p = 0.008) as an independent prognostic factor.

CONCLUSIONS

This study presents detailed clinicopathological characteristics and the prognostic impact of HER2-positivity in endometrial carcinomas. HER2-targeted antibody-drug conjugate therapy may be broadly applicable to endometrial carcinoma.

Landscape of HER2-low breast cancer: Insights from a six-year study on prevalence and clinicopathological characteristics

Human epidermal growth factor receptor 2 (HER2)-low breast cancer has emerged as a subtype of breast cancer, defined by HER2 1+/2+ in immunohistochemistry (IHC) and absence of ERBB2 gene amplification on fluorescence in situ hybridization (FISH). Recent trials showed marked response of HER2-low breast cancer to novel anti-HER2 antibody-drug-conjugates. Data on characteristics of HER2-low breast cancer subtype is limited. Real-world data from the Anatomic Pathology Department of Hotel-Dieu de France, spanning 2017-2023, was retrospectively collected. HER2-positive patients were excluded to compare HER2-low to HER2-zero breast cancer subtypes. Clinicopathological characteristics between the groups were compared using a Chi-Squared test. Out of 1195 patients, we observed 341 (28.5 %) HER2-low breast cancers cases. HER2-positive breast cancer cases (n = 178; 14.9 %) were excluded. There was no significant difference in age and sex between HER2-low and HER2-zero group (p = 0.33 and 0.79, respectively). HER2-low breast cancer was associated with positive estrogen receptor status and positive progesterone receptor status (p < 0.001 and p = 0.01, respectively). Ductal adenocarcinomas were more commonly observed in HER2-low group (p < 0.001). When stratified by hormone (HR) status, 87.4 % of patients had HR-positive status and 12.6 % were HR-negative. Among the HR-negative group, HER2-low tumors tended to show lower proliferation index compared to HER2-zero tumors (25%vs.10 %, p = 0.04). This study showed that HER2-low is distinct from HER2-zero and is common among patients with breast cancer. Clinicopathological features such as histological type differ between HER2-zero and HER2-low breast cancer. Within HR-negative breast cancer, those with low HER2 expression exhibit a less aggressive profile compared to HER2-zero tumors.

Comparison of the Pathological Complete Response Rate and Survival Between HER2-Low and HER2-Zero Breast Cancer in Neoadjuvant Chemotherapy Setting: A Systematic Review and Meta-Analysis

Although HER2-low breast cancer (BC) constitutes almost 50% of all BC types, its impact on the pathological complete response (pCR) rate and survival in early BC is uncertain. As a result, a systematic review was conducted to compare the pCR rate and survival of HER2-low and HER2-zero BC in the neoadjuvant chemotherapy (NACT) setting. Two reviewers independently performed literature searches using EMBASE, PubMed, and Cochrane Libraries internet databases up to June 2023. Finally, 29 studies with 178,294 patients were included. HER2-low BC had a considerably lower pCR rate compared to HER2-zero BC in the entire population (Risk Ratio [RR] = 0.68, P < .001) and in the hormone receptor (HR)-positive subgroup (RR = 0.73, P = .009), but not in the HR-negative subgroup (RR = 0.99, P = .755). Furthermore, patients with HER2-low BC exhibited prolonged disease-free survival (DFS) and overall survival (OS) compared to those with HER2-zero BC, observed in both the entire cohort (DFS: P = .004; OS: P = .008) and the HR-negative subgroup (DFS: P = .009; OS: P < .001). In the HR-positive population, OS was superior in HER2-low BC patients (P < .001), whereas no significant differences in DFS were observed (P = .064). Our findings imply that the pCR rate and prognosis of HER2-low BC are distinguished from those of HER2-zero BC in early BC treated with NACT, which contributes to a better knowledge of the BC subgroup.

Understanding the spectrum of HER2 status in breast cancer: From HER2-positive to ultra-low HER2

HER2 (human epidermal growth factor receptor 2) status in breast cancer spans a spectrum from HER2-positive to ultra-low HER2, each category influencing prognosis and treatment decisions differently. Approximately 20 % of breast cancers overexpress HER2, correlating with aggressive disease and poorer outcomes without targeted therapy. HER2 status is determined through immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), guiding therapeutic strategies. HER2-positive breast cancer exhibits HER2 protein overexpression or gene amplification, benefiting from HER2-targeted therapies like trastuzumab and pertuzumab. In contrast, HER2-negative breast cancer lacks HER2 overexpression and amplification, treated based on hormone receptor status. HER2-low breast cancer represents a newly recognized category with low HER2 expression, potentially benefiting from evolving therapies. Ultra-low HER2 cancers, characterized by minimal expression without gene amplification, challenge conventional classifications and treatment paradigms. Their distinct molecular profiles and clinical behaviors suggest unique therapeutic approaches. Recent diagnostic guideline updates refine HER2 assessment, enhancing precision in identifying patients for targeted therapies. Challenges remain in accurately classifying HER2-low tumors and optimizing treatment efficacy, necessitating ongoing research and innovative diagnostic methods. Understanding the heterogeneity and evolving landscape of HER2 status in breast cancer is crucial for advancing personalized treatment strategies and improving patient outcomes.

The Genomic Landscape of Breast Cancer in Young and Older Women

BACKGROUND

Young women with breast cancer (YWBC; ≤40 years) often have a poorer prognosis than older women with breast cancer (OWBC; ≥65 years). We explored molecular features of tumors from YWBC and OWBC to identify a biologic connection for these patterns.

MATERIALS AND METHODS

We retrospectively analyzed the molecular profiles of 1879 breast tumors. Testing included immunohistochemistry (IHC), in situ hybridization (ISH), and next-generation sequencing. Statistical analyses included Pearson's chi2 test for comparisons, with significance defined as FDR (false discovery rate)-P < .05.

RESULTS

TP53 and BRCA1 somatic mutations were more common in YWBC tumors than in OWBC tumors (53%, 42%; P = .0001, FDR-P = .0025 and 7%, 2%; P = .0001, FDR-P = .0025; respectively). Conversely, OWBC tumors had higher androgen receptor expression (55%, 45%; P = .0002, FDR-P = .0025) higher PD-L1 expression detected by IHC (8%, 5%; P = .0476, FDR-P = .2754), and more frequent PIK3CA mutations (33%, 17%; P = < .0001, FDR-P = < .0001). Among HR+/HER2- samples, YWBC had more gene amplifications in FGF3 (27%, 10%; P = .0353, FDR-P = .2462), FGF4 (27%, 9%; P = .0218, FDR-P = .1668), FGF19 (30%, 12%; P = .034, FDR-P = .2462) and CCND1 (37%, 18%; P = .0344, FDR-P = .2462) than OWBC.

CONCLUSIONS

Our data suggest distinct molecular aberrations exist between YWBC and OWBC. Exploiting these molecular changes could refine our treatment strategies in YWBC and OWBC.

Prognostic impact of histological subtyping in triple-negative breast cancer

The impact of special histological types (ST) in triple-negative breast cancer (TNBC) and its association with overall outcome has gained increasing relevance as survival has been linked to specific histological TNBC subtypes. We evaluated the clinicopathological and survival data of 598 patients with 613 TNBCs, including 464 TNBCs of no special type (NST) and 149 TNBCs ST (low-grade, n = 12, 8.1%; high-grade, n = 112, 75.2%; apocrine and androgen receptor-positive [APO AR], n = 25, 16.8%). Patients with low-grade TNBC ST and TNBC ST APO AR were significantly older (P < 0.001) and had a lower Ki67 index (P < 0.001) than those with TNBC NST. Patients with high-grade TNBC ST were significantly older (P = 0.006) and had poorer pathological responses to neoadjuvant chemotherapy (NAC) (P < 0.001) than those with TNBC NST. Significant survival differences were observed between low-grade TNBC ST, TNBC ST APO AR, high-grade TNBC ST, and TNBC NST in the entire study group (DFS, P = 0.002; DDFS, P = 0.001) and in the non-NAC subgroup (OS, P = 0.034; DFS, P = 0.001; DDFS, P < 0.001). Patients with low-grade TNBC ST had the best survival outcomes. Patients with high-grade TNBC ST showed significantly worse outcomes than those with TNBC NST (entire study group: OS, P = 0.049; DFS, P < 0.001; DDFS, P = 0.001; non-NAC subgroup: OS, P = 0.014; DFS, P < 0.001; DDFS, P < 0.001). We conclude that prognostic stratification of TNBC ST is ultimately important for optimizing the therapeutic management of patients with these rare tumor entities.

Pharmacokinetics and pharmacogenomics of ribociclib in black patients with metastatic breast cancer the LEANORA study

Underrepresented populations' participation in clinical trials remains limited, and the potential impact of genomic variants on drug metabolism remains elusive. This study aimed to assess the pharmacokinetics (PK) and pharmacogenomics (PGx) of ribociclib in self-identified Black women with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2) advanced breast cancer. LEANORA (NCT04657679) was a prospective, observational, multicenter cohort study involving 14 Black women. PK and PGx were evaluated using tandem mass spectrometry and PharmacoScan™ microarray (including CYP3A5*3, *6, and *7). CYP3A5 phenotypes varied among participants: 7 poor metabolizers (PM), 6 intermediate metabolizers (IM), and one normal metabolizer (NM). The area under the curve did not significantly differ between PMs (39,230 h*ng/mL) and IM/NMs (43,546 h*ng/mL; p = 0.38). The incidence of adverse events (AEs) was also similar. We found no association between CYP3A5 genotype and ribociclib exposure. Continued efforts are needed to include diverse populations in clinical trials to ensure equitable treatment outcomes.

Multiparametric profiling of HER2-enriched extracellular vesicles in breast cancer using Single Extracellular VEsicle Nanoscopy

BACKGROUND

Patients with HER2-positive breast cancer can significantly benefit from HER2-directed therapy - such as the monoclonal antibody trastuzumab. However, some patients can develop therapy resistance or change HER2 status. Thus, we urgently need new, noninvasive strategies to monitor patients frequently. Extracellular vesicles (EVs) secreted from tumor cells are emerging as potential biomarker candidates. These membrane-delimited nanoparticles harbor molecular signatures of their origin cells; report rapidly on changes to cellular status; and can be frequently sampled from accessible biofluids.

RESULTS

Using Single Extracellular VEsicle Nanoscopy (SEVEN) platform that combines affinity isolation of EVs with super-resolution microscopy, here we provide multiparametric characterization of EVs with ~ 8 nm precision and molecular sensitivity. We first interrogated cell culture EVs affinity-enriched in tetraspanins CD9, CD63, and CD81; these transmembrane proteins are commonly found on EV membranes. SEVEN robustly provided critical parameters of individual, tetraspanin-enriched EVs: concentration, size, shape, molecular cargo content, and heterogeneity. Trastuzumab-resistant cells (vs. trastuzumab-sensitive) secreted more EVs. Additionally, EVs from trastuzumab-resistant cells had lower tetraspanin density and higher HER2 density. We also evaluated EVs affinity-enriched in HER2; we found that these EVs (vs. tetraspanin-enriched) were larger and more elongated. We further optimized analytical sample processing to assess a rare population of HER2-enriched EVs from patient plasma. In breast cancer patients with elevated HER2 protein expression (vs. controls), HER2-enriched EVs had distinct characteristics including typically increased number of tetraspanin molecules and larger size. Importantly, these EVs were on average 25-fold more abundant compared to no cancer controls.

CONCLUSIONS

SEVEN revealed unique characteristics of HER2-enriched EVs in cultured cells and complex biological fluid. In combination with current clinical approaches, this method is well poised to support precise therapeutic decisions.

SERS-Based Droplet Microfluidic Platform for Sensitive and High-Throughput Detection of Cancer Exosomes

Exosomes, nanosized extracellular vesicles containing biomolecular cargo, are increasingly recognized as promising noninvasive biomarkers for cancer diagnosis, particularly for their role in carrying tumor-specific molecular information. Traditional methods for exosome detection face challenges such as complexity, time consumption, and the need for sophisticated equipment. This study addresses these challenges by introducing a novel droplet microfluidic platform integrated with a surface-enhanced Raman spectroscopy (SERS)-based aptasensor for the rapid and sensitive detection of HER2-positive exosomes from breast cancer cells. Our approach utilized an on-chip salt-induced gold nanoparticles (GNPs) aggregation process in the presence of HER2 aptamers and HER2-positive exosomes, enhancing the hot spot-based SERS signal amplification. This platform achieved a limit of detection of 4.5 log10 particles/mL with a sample-to-result time of 5 min per sample. Moreover, this platform has been successfully applied for HER2 status testing in clinical samples to distinguish HER2-positive breast cancer patients from HER2-negative breast cancer patients. High sensitivity, specificity, and the potential for high-throughput screening of specific tumor exosomes make this SERS-based droplet system a potential liquid biopsy technology for early cancer diagnosis.

Desire for pregnancy and fertility preservation in young patients with breast cancer

BACKGROUND

Data on the desire for pregnancy and the status of fertility preservation (FP) in patients with breast cancer remain unclear. This study aimed to determine the status of patients with breast cancer who desired pregnancy and FP implementation before systemic therapy.

METHODS

This retrospective study surveyed the institutional clinical databases and electronic medical records of patients aged < 43 years with stages 0-III primary breast cancer during surgery and treated between April 2020 and March 2021. All patients were enquired about their desire for pregnancy in a questionnaire by "present," "absent," and "unsure" at their first visit. The correlation between the desire for pregnancy, implementation of FP, and clinicopathological factors was investigated.

RESULTS

Among 1005 patients who underwent surgery for primary breast cancer, 146 were included in the analysis. Of them, 34 (23.3%) patients had a desire for pregnancy, and 45 (30.8%) chose "unsure." Factors associated with the desire for pregnancy were younger age during surgery (p < 0.0022), unmarried status (p < 0.001), nulliparity (p < 0.001), early-stage disease (p = 0.0016), and estrogen receptor positivity (p = 0.008). Among 115 patients who underwent systemic therapy, 13 (11.3%) underwent FP before systemic therapy. Patients who were nulliparous frequently pursued FP (p = 0.0195). The proportion of FP implementation was low in patients who received neoadjuvant chemotherapy (p = 0.0863).

CONCLUSIONS

Our study suggests that unmarried, nulliparous, and younger patients were more interested in pregnancy, and nulliparous patients frequently pursued FP.

Genomic and transcriptomic landscape of HER2-low breast cancer

BACKGROUND

Novel agents have expanded the traditional HER2 definitions to include HER2-Low (HER2L) Breast Cancer (BC). We sought to evaluate the distinct molecular characteristics of HER2L BC to understand potential clinical/biologic factors driving resistance and clinical outcomes.

METHODS

Retrospective analysis was performed on 13,613 BC samples, tested at Caris Life Sciences via NextGen DNA/RNA Sequencing. BC subtypes were defined by IHC/ISH. CODEai database was used to access clinical outcomes from insurance claims data.

RESULTS

Overall, mutational landscape was similar between HER2L and classical subsets of HR+and HRneg cohorts. TP53 mutations were significantly higher in HRneg/HER2L group vs. HR+/HER2L tumors (p<0.001). A higher mutation rate of PIK3CA was observed in HRneg/HER2L tumors compared to TNBC subtype (p=0.016). PD-L1 positivity was elevated in HRneg/HER2L tumors compared to HR+/HER2L tumors, all p<0.01. Patients with HR+/HER2L tumors treated with CDK4/6 inhibitors had similar OS compared to pts with HR+/HER2-0 (HR=0.89, p=0.012). 27.2% of HR+/HER2L pts had activating PIK3CA mutations. Among HR+PIK3CA mutated tumors, HER2L pts treated with alpelisib showed no difference in OS vs. HER2-0 alpelisib-treated pts (HR=1.23, p=0.517). 13.9% of HER2L TNBC pts were PD-L1+. Interestingly, pts with PD-L1+ HER2L/HRneg (TNBC) treated with immune checkpoint inhibitors (ICI) showed improved OS than HER2-0 TNBC (HR=0.61, p=0.046).

CONCLUSION

Our findings expand the understanding of the molecular profile of the HER2L subgroup and comparison to the classically defined breast cancer subgroups. Genomic risk assessments after progression on novel therapeutics can be assessed to better define implications for mechanisms of resistance.

The utility of ultrafast MRI and conventional DCE-MRI for predicting histologic aggressiveness in patients with breast cancer

BACKGROUND

Prediction of histologic prognostic markers is important for determining management strategy and predicting prognosis.

PURPOSE

To identify important features of ultrafast and conventional dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) that can predict histopathologic prognostic markers in patients with breast cancer.

MATERIAL AND METHODS

Preoperative MRI scans of 158 consecutive women (mean age = 54.0 years; age range = 29-86 years) with 163 breast cancers between February 2021 and August 2022 were retrospectively reviewed. Inter-observer agreements for ultrafast MRI parameters were analyzed by two radiologists. The qualitative and quantitative MRI parameters were correlated with histopathologic prognostic markers including molecular subtypes and histologic invasiveness.

RESULTS

Inter-observer agreements for ultrafast MRI parameters were excellent (intraclass correlation coefficients of area under the kinetic curve [AUC], maximum slope [MS], maximum enhancement [ME], and slope = 0.987, 0.844, 0.822, and 0.760, respectively). Triple-negative breast cancers (TNBC) were significantly associated with rim enhancement (odds ratio [OR] = 9.4, P = 0.003) and peritumoral edema (OR = 17.9, P = 0.002), compared to luminal cancers. Invasive cancers were associated with lesion type-mass, increased delayed washout, angiovolume, ME, slope, MS, and AUC, compared to in situ cancers. In regression analysis, the combination of MS (>46.2%/s) (OR = 5.7, P = 0.046) and delayed washout (>17.5%) (OR = 17.6, P = 0.01), and that of AUC (>27,410.3) (OR = 9.6, P = 0.04), delayed washout (>17.5%) (OR = 8.9, P = 0.009), and lesion-type mass (OR = 4.6, P = 0.04) were predictive of histologic invasiveness.

CONCLUSION

Conventional DCE-MRI with ultrafast imaging can provide useful information for predicting histologic underestimation and aggressive molecular subtype. MS and AUC on ultrafast MRI can be potential imaging markers for predicting histologic upgrade from DCIS to invasive cancer with high reliability.

Absolute lymphocyte count predicts efficacy of palbociclib in patients with metastatic luminal breast cancer

BACKGROUND

Absolute lymphocyte count (ALC) is a predictive and prognostic factor for various tumor types, including breast cancer. Palbociclib is a CDK4/6 inhibitor widely used for the treatment of metastatic estrogen receptor (ER)-positive, HER2-negative breast cancer. However, predictive biomarkers of the efficacy of palbociclib remain unelucidated. We conducted a retrospective study to examine the predictive value of the baseline ALC in patients treated with palbociclib.

METHODS

The medical records of patients with ER-positive, HER2-negative breast cancer treated with palbociclib plus hormonal therapy between December 2017 and December 2021 were analyzed retrospectively. The cutoff value of ALC was set at 1800 cells/μL at the initiation of palbociclib treatment. The clinical benefit rate (CBR) was defined as the rate of complete or partial response or stable disease for at least 6 months. Progression-free survival (PFS) rates were estimated using the Kaplan-Meier method and compared using the log-rank test. Univariate and multivariate analyses were performed using Cox proportional hazards regression.

RESULTS

All of the 202 patients were women, with a median age of 59 years and a performance status (PS) of ≤ 2. The median numbers of lines of chemotherapy and endocrine therapy before palbociclib treatment were 0 (range, 0-9) and 1 (range, 0-7), respectively. Fifty-one patients had liver metastases. Forty-six patients tested negative for progesterone receptor (PgR) expression. The median follow-up time was 9.1 months. The CBR was significantly higher in the ALC-high group than in the ALC-low group (79% vs. 60%; P = 0.018). The median PFS was significantly longer in the ALC-high group than in the ALC-low group (26.8 months vs. 8.4 moths, respectively; P = 0.000013). ALC, age, PS, PgR status, prior chemotherapy, prior endocrine therapy, and liver metastasis were entered into the multivariate analysis. ALC was identified as an independent factor for PFS (P = 0.00085), along with liver metastasis (P = 0.0020), PS (P = 0.026), and prior endocrine therapy (P = 0.019).

CONCLUSION

ALC can serve as a predictor of palbociclib efficacy in patients with metastatic ER-positive, HER2-negative breast cancer.

Characterization and spatial distribution of infiltrating lymphocytes in medullary, and lymphocyte-predominant triple negative breast cancers

Medullary carcinoma of the breast (MedBC) is a rare histological type that accounts for less than 5% of all invasive breast cancers. Here, we performed an exploratory study aimed to determine whether imaging mass cytometry (IMC) can be used to characterize the immune infiltration and the spatial distribution heterogeneity in the rare subtype of MedBC compared to atypical MedBC and TNBC-TILS+ tumors. In both MedBC and TNBC-TILs+, there was a notable enrichment of immune cells in the peripheral regions of the tumors, whereas in atypical MedBC, the immune cells exhibited a central enrichment pattern. This distribution of infiltrated cells reflects an active immune recruitment correlated to more favorable prognosis. In MedBC, spatial analysis shows that immune cells are localized at a greater distance from the tumor cells. IMC highlights the heterogeneity of immune microenvironment across three main subtypes of breast tumors and could help to define distinct immune patterns.

Trastuzumab deruxtecan in HER2-positive advanced breast cancer with or without brain metastases: a phase 3b/4 trial

Trastuzumab deruxtecan (T-DXd) intracranial activity has been observed in small or retrospective patient cohorts with human epidermal growth factor receptor 2-positive (HER2+) advanced/metastatic breast cancer (mBC) and stable or active (untreated/previously treated and progressing) brain metastases (BMs). The phase 3b/4 DESTINY-Breast12 study investigated T-DXd in patients with HER2+ mBC and is, to our knowledge, the largest prospective study of T-DXd in patients with BMs in this setting. Patients (stable/active BMs (n = 263) and no BMs (n = 241)) treated with one or more prior anti-HER2-based regimens received T-DXd (5.4 mg per kg). Primary endpoints were progression-free survival (PFS; BMs cohort) and objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1 (non-BMs cohort). Additional endpoints included central nervous system (CNS) PFS, ORR, time to second progression, CNS ORR (BMs cohort), incidence of new symptomatic CNS metastases (non-BMs cohort), time to progression, duration of response, overall survival and safety (both cohorts). No formal hypothesis testing was conducted for this single-arm, open-label study. In the BMs cohort, 12-month PFS was 61.6% (95% confidence interval (CI): 54.9-67.6), and 12-month CNS PFS was 58.9% (95% CI: 51.9-65.3). In the non-BMs cohort, ORR was 62.7% (95% CI: 56.5-68.8). Grade 3 or higher adverse events occurred in 51% (BMs cohort) and 49% (non-BMs cohort) of patients. Investigator-reported interstitial lung disease/pneumonitis occurred in 16% (grade ≥3: 3%) of patients with BMs and 13% (grade ≥3: 1%) of patients without BMs. These data show substantial and durable overall and intracranial activity for T-DXd, supporting its use in previously treated patients with HER2+ mBC irrespective of stable/active baseline BMs. ClinicalTrials.gov identifier: NCT04739761 .

Dual HER2 inhibition: mechanisms of synergy, patient selection, and resistance

HER2-targeted therapies for patients with HER2+ breast cancer are rapidly evolving, offering a range of more complex and personalized treatment options. Currently, an array of anti-HER2 monoclonal antibodies, tyrosine kinase inhibitors and antibody-drug conjugates are administered, sometimes alongside chemotherapy or endocrine therapy, both in curative and palliative contexts. However, the heterogeneous nature of HER2+ breast cancer demands a deeper understanding of disease biology and its role in responsiveness to novel HER2-targeted agents, as well as non-HER2-targeted therapies, in order to optimize patient outcomes. In this Review, we revisit the mechanisms of action of HER2-targeted agents, examine the evidence supporting the use of dual HER2 blockade in patients with HER2-amplified tumours, and explore the role of biomarkers in guiding future treatment strategies. We also discuss potential implications for the future treatment of patients with HER2+ breast cancer.

HER2DX Genomic Assay in HER2-Positive Early Breast Cancer Treated with Trastuzumab and Pertuzumab: A Correlative Analysis from the PHERGain Phase II Trial

PURPOSE

The purpose of this study was to assess the predictive capability of HER2DX assay following (neo)adjuvant trastuzumab-pertuzumab (HP)-based therapy in HER2-positive (HER2+) early breast cancer.

EXPERIMENTAL DESIGN

HER2DX was analyzed in baseline pretreatment tumors from the PHERGain trial. Patients with stage I-IIIA HER2+ early breast cancer were randomized to group A [docetaxel, carboplatin, and HP (TCHP)] and group B (HP ± endocrine therapy). PET response was evaluated after two cycles. Group A received TCHP for six cycles regardless of PET response. Group B continued with HP ± endocrine therapy for six cycles (PET responders) or with TCHP for six cycles (PET nonresponders). The primary objective of this retrospective study was to associate the HER2DX pathologic complete response (pCR) score with pCR. The secondary objective was the association of the HER2DX risk score with 3-year invasive disease-free survival (iDFS).

RESULTS

HER2DX was performed on 292 (82.0%) tumors. The overall pCR rate was 38.0%, with pCR rates of 56.4% in group A and 33.8% in group B. In multivariable analysis including treatment and clinicopathologic factors, the HER2DX pCR score (continuous variable) significantly correlated with pCR [OR, 1.29; 95% confidence interval (CI), 1.10-1.54; P < 0.001]. HER2DX-defined pCR-high, -med, and -low groups exhibited pCR rates of 50.4%, 35.8%, and 23.2%, respectively (pCR-high vs. pCR-low OR, 3.27; 95% CI, 1.54-7.09; P < 0.001). In patients with residual disease, the HER2DX high-risk group demonstrated numerically worse 3-year iDFS than the low-risk group (89.8% vs. 100%; HR, 2.70; 95% CI, 0.60-12.18; P = 0.197).

CONCLUSIONS

HER2DX predicts pCR in the context of neoadjuvant HP-based therapy, regardless of chemotherapy addition, and might identify patients at higher risk of recurrence among patients with residual disease.

Unveiling the mysteries of HER2-low expression in breast cancer: pathological response, prognosis, and expression level alterations

BACKGROUND

The novel anti-HER2 antibody drug conjugates (ADCs) can effectively improve the long-term survival of patients with HER2-low expression breast cancer. However, pathological responses to neoadjuvant therapy (NAT) within HER2-low expression breast cancer, the relationship between pathological response and prognosis and the transformation of HER2 status are all now poorly understood.

METHODS

The patients with HER2-0 and HER2-low expression breast cancer receiving NAT at Harbin Medical University Cancer Hospital between Jan. 2014 and Nov. 2018 were retrospectively explored. HER2 low expression refers to the IHC 1 + or 2 + and FISH negative. The Kappa test was utilized for analyzing the consistency rate of HER2 expression. To evaluate disease-free survival (DFS) and overall survival (OS), this research employed both the Kaplan-Meier analysis and the Cox regression.

RESULTS

In this study, 178 patients with HER2-0 and 344 patients with HER2-low expression breast cancer were included. In comparison with the HER2-0 group, it is shown that patients in the HER2-low group have more possibility to be younger compared to those 50 years old (P < 0.014), have more premenopausal patients (P < 0.001), a higher proportion of hormone receptor (HR) positive patients (P < 0.001), and less proportion of stage III V patients (P < 0.034). When NAT was finished, the pCR rate became 23.6% in the HER2-0 group while 22.1% in the HER2-low group, and there was also a higher pCR rate in HR- patients in comparison with that in HR + patients (P < 0.01). Considering HER2 expression inconsistency, the overall HER2 inconsistency rate was 30.4% (Kappa = 0.431, P < 0.01). Among patients initially diagnosed as HER2-0, 34% (N = 61) were re-diagnosed as HER2-low after NAT. After stratification by HR expression status, HR+/HER2-0 patients transformed to HER2-low after NAT in 37%, and 32% of HR- patients changed from HER2-0 to HER2-low. In this survival analysis, there were both better DFS rates (P = 0.009) and OS rates (P = 0.026) in the HR-/HER2-low patients in comparison with the HR-/HER2-0 patients, while the HER2-0 and HER2-low patients in the HR + group had no significant survival difference. Additionally, for non-pCR patients, there was better DFS (P = 0.029) and OS (P = 0.038) in the HER2-low group in comparison with that of the HER2-0 group, while no significant survival difference exists between pCR patients.

CONCLUSION

After HR stratification, there are unique clinical characteristics and prognostic outcomes in HER2-low expression breast cancer, which indicates the potential to become a specific molecular subtype of breast cancer. The significant instability of HER2-low expression status between primary tumor and residual invasive disease suggests that multiple detections of HER2 status should be emphasized in NAT strategies.

Characterization of HER2-Low Breast Tumors among a Cohort of Colombian Women

HER2-low tumors have shown promise in response to antibody-drug conjugates (ADCs) in recent clinical trials, underscoring the need to characterize this group's clinical phenotype. In this study, we aimed to explore the clinicopathological features, survival rates, and HER2 amplicon mRNA expression of women affected with HER2-low breast cancer, compared with HER2-negative and HER2-positive groups. We included 516 breast cancer patients from Colombia, for whom we compared clinicopathological features, mRNA expression of three HER2 amplicon genes (ERBB2, GRB7 and MIEN1), survival and risk of mortality between HER2-low cases (1+ or 2+ with negative in situ hybridization (ISH) result) with HER2-positive (3+ or 2+ with positive ISH test) and HER2-negative (0+) cases. A higher proportion of patients with better-differentiated tumors and a lower proliferation index were observed for HER2-low tumors compared to the HER2-positive group. Additionally, HER2-low tumors showed higher mRNA expression of the ERBB2 gene and longer overall survival rates compared to HER2-negative cases. Nonetheless, a Cox-adjusted model by ER status and clinical stage showed no statistically significant differences between these groups. Our results show differences in important clinicopathological features between HER2-low and both HER2-positive and negative tumors. Given this unique phenotype, it is crucial to evaluate the potential advantages of ADC therapies for this emerging subtype of breast cancer.

HER2-positive grade 1 invasive carcinomas of the breast

AIMS

The American Society of Clinical Oncology and College of American Pathologists HER2-guidelines recommend repeat testing for most grade 1 mammary carcinomas that are HER2-positive in the core biopsy. This study aimed to assess the value of repeat HER2-testing and the histological features of HER2-positive grade 1 carcinomas.

METHODS AND RESULTS

A case-series of HER2-results of grade 1 carcinomas was conducted of patients with no pre-operative systemic treatment over a 5-year period. HER2-positive carcinomas had histological review. Twelve HER2-positive carcinomas were initially reported as grade 1. On review, two were reclassified as grade 2. The remaining 10 carcinomas represented 2% of the 508 grade 1 carcinomas. Eight HER2-positive grade 1 carcinomas from other years were also studied. HER2-positive carcinomas more often had marked nuclear pleomorphism (50 versus 6%) and were more often oestrogen receptor-negative (17 versus 0.8%) and progesterone receptor-negative (28 versus 8%) compared with HER2-negative grade 1 carcinomas. Six carcinomas that were HER2 3+ in the core biopsy were also 3+ on repeat assessment. Five of seven carcinomas that were 2+ amplified in the core biopsy were also HER2-positive in the excision.

CONCLUSIONS

HER2-positive grade 1 carcinomas are uncommon, and more often have marked nuclear pleomorphism and lack oestrogen receptor and progesterone receptor expression compared with HER2-negative grade 1 carcinomas. A HER2-poitive result in the core biopsy was confirmed in 11 of 13 tumours that had repeat testing.

PAM50 breast cancer subtypes and survival of patients in rural Ethiopia without adjuvant treatment: a prospective observational study

PURPOSE

Survival rates of breast cancer (BC) patients are particularly low in rural regions in sub-Saharan Africa (SSA) which is due to limited access to therapy. In recent years, gene expression profiling (GEP) of BC showed a strong prognostic value in patients with local tumour surgery and (neo)adjuvant treatment. The aim of this study was to evaluate the impact of intrinsic subtypes on survival of patients in rural Ethiopia without any (neo)adjuvant therapy.

METHODS

In total, 113 female patients from Aira Hospital with histologically proven BC and treated only with surgery were included in this study. All samples were analysed by immunohistochemistry (IHC) for estrogen receptor, progesterone receptor, HER2 and Ki67, as well as RNA-expression analysis for PAM50 subtyping.

RESULTS

A positive hormone receptor status was found in 69.0% of the tumours and intrinsic subtyping demonstrated Luminal B to be the most common subtype (34.5%). Follow-up data was available for 79 of 113 patients. Two-year overall survival (OS) was 57.3% and a considerably worse OS was observed in patients with Basal-like BC compared to Luminal A BC. Moreover, advanced tumours showed an increased risk of mortality.

CONCLUSION

The OS was very low in the patient cohort that received no (neo)adjuvant treatment. Immunohistochemistry and GEP confirmed endocrine-sensitive tumours in more than half of the patients, with a large proportion of Luminal B, HER2-enriched and Basal-like tumours so that adjuvant chemotherapy should be recommended.

Protein Expression, Amplification, and Mutation of HER2 Gene in Canine Primary Pulmonary Adenocarcinomas: Preliminary Results

Recently, human epidermal growth factor receptor 2 (HER2) has emerged as a therapeutic target of interest for non-small-cell lung cancer in humans. The role of HER2 in canine pulmonary adenocarcinomas is poorly documented. To address this gap, this study employed three methodologies: immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and next-generation sequencing (NGS) to investigate the protein expression, gene amplification, and mutation of HER2 in 19 canine primary pulmonary adenocarcinomas. By IHC, 3 out of 19 cases were overexpressed 3+, 6 were 2+, and 10 were negative. With FISH, 2 cases were amplified (12.5%), 3 were inadequate for the analyses, and the others were non-amplified. With NGS, seven cases were inadequate. All other cases were wild-type, except for one IHC 3+ case, which was amplified with FISH and with a specific mutation already described in human pulmonary adenocarcinoma, V659E. This mutation is probably sensitive to tyrosine kinase inhibitory drugs. These results are similar to those in human medicine and to the few data in the literature on canine lung carcinomas; the presence of 12.5% of amplified cases in dogs lays the foundation for future targeted drugs against HER2 alterations.

Whole-Body HER2 Heterogeneity Identified on HER2 PET in HER2-Negative, -Low, and -Positive Metastatic Breast Cancer

Understanding which patients with human epidermal growth factor receptor 2 (HER2)-negative or -low metastatic breast cancer (MBC) benefit from HER2-targeted strategies is urgently needed. We assessed the whole-body heterogeneity of HER2 expression on 89Zr-trastuzumab PET (HER2 PET) and the diagnostic performance of HER2 PET in a large series of patients, including HER2-negative and -low MBC. Methods: In the IMPACT-MBC study, patients with newly diagnosed and nonrapidly progressive MBC of all subtypes were included. Metastasis HER2 status was determined by immunohistochemistry and in situ hybridization.89Zr-trastuzumab uptake was quantified as SUVmax and SUVmean HER2 immunohistochemistry was related to the quantitative 89Zr-trastuzumab uptake of all metastases and corresponding biopsied metastasis, uptake heterogeneity, and qualitative scan evaluation. A prediction algorithm for HER2 immunohistochemistry positivity based on uptake was developed. Results: In 200 patients, 89Zr-trastuzumab uptake was quantified in 5,163 metastases, including 186 biopsied metastases. With increasing HER2 immunohistochemistry status, uptake was higher (geometric mean SUVmax of 7.0, 7.6, 7.3, and 17.4 for a HER2 immunohistochemistry score of 0, 1, 2, or 3+, respectively; P < 0.001). High uptake exceeding 14.6 (90th percentile) was observed in one third of patients with a HER2-negative or -low metastasis biopsy. The algorithm performed best when lesion site and size were incorporated (area under the curve, 0.86; 95% CI, 0.79-0.93). Conclusion: HER2 PET had good diagnostic performance in MBC, showing considerable whole-body HER2 heterogeneity and uptake above background in HER2-negative and -low MBC. This provides novel insights into HER2-negative and -low MBC compared with standard HER2 immunohistochemistry on a single biopsy.

Analysis of PIK3CA mutations in the primary and recurrent tumors of hormone receptor positive/human epidermal growth factor receptor 2 negative breast cancer

OBJECTIVE

Our aim was to compare the PIK3CA mutation status in matched primary and recurrent tumors of hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) breast cancer (BC) to gain insight into the optimization of patient selection and detection time for PIK3CA-targeted therapy.

METHODS

The data were from 3035 patients with BC diagnosed at the Breast Disease Center, Peking University First Hospital, between January 2008 and December 2017. Matched primary and recurrent samples were profiled using amplification-refractory mutation system-polymerase chain reaction covering 11 mutational hotspots in PIK3CA.

RESULTS

PIK3CA mutations were detected in 54.3% primary tumors and 48.6% corresponding recurrences. PIK3CA mutation was detected in 37.5% cases in the locoregional recurrent group and 40.0% of distant metastasis, without a statistical difference. Besides, PIK3CA mutations were concordant in 88.6% of the matched pairs. For patients treated with neoadjuvant chemotherapy, 100% concordance was observed. However, PIK3CA mutation was neither correlated with clinicopathological features nor associated with clinical outcomes.

CONCLUSIONS

Mutations in PIK3CA in HR+/HER2- BC generally progressed to recurrent tumors. The high concordance rate of PIK3CA mutation status between primary tumors and corresponding recurrences suggests that the detection of primary tumors could be a substitute approach when recurrent samples are not easily obtainable.

A nomogram to predict the pathological complete response in patients with breast cancer based on the TILs-US score

BACKGROUND

The tumor-infiltrating lymphocytes-ultrasonography score is a calculation system for predicting lymphocyte-predominant breast cancers in surgical specimens. A nomogram based on the tumor-infiltrating lymphocytes-ultrasonography score was developed to predict the pathological complete response in breast cancer treated with neoadjuvant chemotherapy.

METHODS

A retrospective evaluation was conducted on 118 patients with breast cancer treated with neoadjuvant chemotherapy at Hiroshima University Hospital. Tumor-infiltrating lymphocytes-ultrasonography scores ≥4 were classified as high. A nomogram was developed using a stepwise logistic regression model for pathological complete response (ypT0 ypN0), based on the smallest Akaike information criterion. The predictive ability and clinical usefulness of the nomogram were also evaluated.

RESULTS

Among 118 patients, 34 (28.8%) achieved a pathological complete response, and 52 (44.1%) exhibited high tumor-infiltrating lymphocytes-ultrasonography. In multivariate logistic regression analysis, high tumor-infiltrating lymphocytes-ultrasonography (odds ratio, 6.01; P < 0.001), clinical complete response (odds ratio, 4.83; P = 0.004) and hormone receptor (odds ratio, 3.48; P = 0.038) were independent predictors of pathological complete response. A nomogram based on tumor-infiltrating lymphocytes-ultrasonography score, clinical complete response, hormone receptor and clinical N status was developed. The nomogram showed an area under the curve of 0.831 and a bias-corrected area under the curve of 0.809. The calibration plot showed a good fit between the expected and actual pathological complete response values. Decision curve analysis also showed the clinical utility of the nomogram for predicting pathological complete responses.

CONCLUSIONS

A nomogram based on the tumor-infiltrating lymphocytes-ultrasonography score exhibited a favorable predictive ability for pathological complete response in patients with breast cancer, which can be useful in predicting the residual disease status after neoadjuvant chemotherapy.

Treatment Outcomes after Postoperative Radiotherapy in Triple-Negative Breast Cancer: Multi-Institutional Retrospective Study (KROG 17-05)

BACKGROUND

We designed a multi-institutional retrospective study to investigate the previously unreported failure pattern, survivals, and prognostic factors after postoperative radiotherapy (PORT) in triple negative breast cancer (TNBC) patients in South Korea.

MATERIALS AND METHODS

We retrospectively reviewed 699 patients with TNBC who underwent PORT at six institutions between 2008 and 2010. The median follow-up period was 94 months (range: 7-192 months). There were 216, 380, and 100 patients in stages I, II, and III, respectively.

RESULTS

After 94 months post-treatment, all patients with pathologic complete remission after neoadjuvant chemotherapy were alive without any failure. Distant metastasis was the main cause of failure. The 5-year overall survival rate was 91.4%, 5-year loco-regional relapse-free survival rate (LRRFS) was 92.3%, 5-year distant metastasis-free survival rate (DMFS) was 89.4%, and 5-year disease-free survival rate (DFS) was 85.2%. On multivariate (Cox) analysis, T and N stages were significant prognostic factors for survival, and lympho-vascular invasion (LVI) was a significant factor for LRRFS and DMFS. Ki-67 expression was significantly associated with LRRFS and DFS.

CONCLUSION

We verified that T and N stages, LVI, and Ki-67 expression were significantly associated with survival outcomes after PORT in TNBC.

Challenges and improvements in HER2 scoring and histologic evaluation: insights from a national proficiency testing scheme for breast cancer diagnosis in China

BACKGROUND

In 2022, our team launched the pioneering national proficiency testing (PT) scheme for the pathological diagnosis of breast cancer, rapidly establishing its credibility throughout China. Aiming to continuously monitor and improve the proficiency of Chinese pathologists in breast pathology, the second round of the PT scheme was initiated in 2023, which will expand the number of participating institutions, and will conduct a nationwide investigation into the interpretation of HER2 0, 1+, and 2+/FISH- categories in China.

METHODS

The methodology employed in the current round of PT scheme closely mirrors that of the preceding cycle in 2022, which is designed and implemented according to the "Conformity assessment-General requirements for proficiency testing"(GB/T27043-2012/ISO/IEC 17043:2010). More importantly, we utilized a statistics-based method to generate assigned values to enhance their robustness and credibility.

RESULTS

The final PT results, published on the website of the National Quality Control Center for Cancer ( http://117.133.40.88:3927 ), showed that all participants passed the testing. However, a few institutions demonstrated systemic biases in scoring HER2 0, 1+, and 2+/FISH- with accuracy levels below 59%, considered unsatisfactory. Especially, the concordance rate for HER2 0 cases was only 78.1%, indicating challenges in distinguishing HER2 0 from low HER2 expression. Meanwhile, areas for histologic type and grade interpretation improvement were also noted.

CONCLUSIONS

Our PT scheme demonstrated high proficiency in diagnosing breast cancer in China. But it also identified systemic biases in scoring HER2 0, 1+, and 2+/FISH- at some institutions. More importantly, our study highlighted challenges in the evaluation at the extreme lower end of the HER2 staining spectrum, a crucial area for further research. Meanwhile, it also revealed the need for improvements in interpreting histologic types and grades. These findings strengthened the importance of robust quality assurance mechanisms, like the nationwide PT scheme conducted in this study, to maintain high diagnostic standards and identify areas requiring further training and enhancement.

Criteria for assessing evidence for biomarker-targeted therapies in rare cancers-an extrapolation framework

Background

Advances in targeted therapy development and tumor sequencing technology are reclassifying cancers into smaller biomarker-defined diseases. Randomized controlled trials (RCTs) are often impractical in rare diseases, leading to calls for single-arm studies to be sufficient to inform clinical practice based on a strong biological rationale. However, without RCTs, favorable outcomes are often attributed to therapy but may be due to a more indolent disease course or other biases. When the clinical benefit of targeted therapy in a common cancer is established in RCTs, this benefit may extend to rarer cancers sharing the same biomarker. However, careful consideration of the appropriateness of extending the existing trial evidence beyond specific cancer types is required. A framework for extrapolating evidence for biomarker-targeted therapies to rare cancers is needed to support transparent decision-making.

Objectives

To construct a framework outlining the breadth of criteria essential for extrapolating evidence for a biomarker-targeted therapy generated from RCTs in common cancers to different rare cancers sharing the same biomarker.

Design

A series of questions articulating essential criteria for extrapolation.

Methods

The framework was developed from the core topics for extrapolation identified from a previous scoping review of methodological guidance. Principles for extrapolation outlined in guidance documents from the European Medicines Agency, the US Food and Drug Administration, and Australia's Medical Services Advisory Committee were incorporated.

Results

We propose a framework for assessing key assumptions of similarity of the disease and treatment outcomes between the common and rare cancer for five essential components: prognosis of the biomarker-defined cancer, biomarker test analytical validity, biomarker actionability, treatment efficacy, and safety. Knowledge gaps identified can be used to prioritize future studies.

Conclusion

This framework will allow systematic assessment, standardize regulatory, reimbursement and clinical decision-making, and facilitate transparent discussions between key stakeholders in drug assessment for rare biomarker-defined cancers.

Preoperative MRI Features Associated With Axillary Nodal Burden and Disease-Free Survival in Patients With Early-Stage Breast Cancer

OBJECTIVE

To investigate the potential association among preoperative breast MRI features, axillary nodal burden (ANB), and disease-free survival (DFS) in patients with early-stage breast cancer.

MATERIALS AND METHODS

We retrospectively reviewed 297 patients with early-stage breast cancer (cT1-2N0M0) who underwent preoperative MRI between December 2016 and December 2018. Based on the number of positive axillary lymph nodes (LNs) determined by postoperative pathology, the patients were divided into high nodal burden (HNB; ≥3 positive LNs) and non-HNB (<3 positive LNs) groups. Univariable and multivariable logistic regression analyses were performed to identify independent risk factors associated with ANB. Predictive efficacy was evaluated using the receiver operating characteristic (ROC) curve and area under the curve (AUC). Univariable and multivariable Cox proportional hazards regression analyses were performed to determine preoperative features associated with DFS.

RESULTS

We included 47 and 250 patients in the HNB and non-HNB groups, respectively. Multivariable logistic regression analysis revealed that multifocality/multicentricity (adjusted odds ratio [OR] = 3.905, 95% confidence interval [CI]: 1.685-9.051, P = 0.001) and peritumoral edema (adjusted OR = 3.734, 95% CI: 1.644-8.479, P = 0.002) were independent risk factors for HNB. Combined peritumoral edema and multifocality/multicentricity achieved an AUC of 0.760 (95% CI: 0.707-0.807) for predicting HNB, with a sensitivity and specificity of 83.0% and 63.2%, respectively. During the median follow-up period of 45 months (range, 5-61 months), 26 cases (8.75%) of breast cancer recurrence were observed. Multivariable Cox proportional hazards regression analysis indicated that younger age (adjusted hazard ratio [HR] = 3.166, 95% CI: 1.200-8.352, P = 0.021), larger tumor size (adjusted HR = 4.370, 95% CI: 1.671-11.428, P = 0.002), and multifocality/multicentricity (adjusted HR = 5.059, 95% CI: 2.166-11.818, P < 0.001) were independently associated with DFS.

CONCLUSION

Preoperative breast MRI features may be associated with ANB and DFS in patients with early-stage breast cancer.

Development and validation of machine learning models for predicting HER2-zero and HER2-low breast cancers

OBJECTIVES

To develop and validate machine learning models for human epidermal growth factor receptor 2 (HER2)-zero and HER2-low using MRI features pre-neoadjuvant therapy (NAT).

METHODS

Five hundred and sixteen breast cancer patients post-NAT surgery were randomly divided into training (n = 362) and internal validation sets (n = 154) for model building and evaluation. MRI features (tumour diameter, enhancement type, background parenchymal enhancement, enhancement pattern, percentage of enhancement, signal enhancement ratio, breast oedema, and apparent diffusion coefficient) were reviewed. Logistic regression (LR), support vector machine (SVM), k-nearest neighbour (KNN), and extreme gradient boosting (XGBoost) models utilized MRI characteristics for HER2 status assessment in training and validation datasets. The best-performing model generated a HER2 score, which was subsequently correlated with pathological complete response (pCR) and disease-free survival (DFS).

RESULTS

The XGBoost model outperformed LR, SVM, and KNN, achieving an area under the receiver operating characteristic curve (AUC) of 0.783 (95% CI, 0.733-0.833) and 0.787 (95% CI, 0.709-0.865) in the validation dataset. Its HER2 score for predicting pCR had an AUC of 0.708 in the training datasets and 0.695 in the validation dataset. Additionally, the low HER2 score was significantly associated with shorter DFS in the validation dataset (hazard ratio: 2.748, 95% CI, 1.016-7.432, P = .037).

CONCLUSIONS

The XGBoost model could help distinguish HER2-zero and HER2-low breast cancers and has the potential to predict pCR and prognosis in breast cancer patients undergoing NAT.

ADVANCES IN KNOWLEDGE

HER2-low-expressing breast cancer can benefit from the HER2-targeted therapy. Prediction of HER2-low expression is crucial for appropriate management. MRI features offer a solution to this clinical issue.

A population-based study on trajectories of HER2 status during neoadjuvant chemotherapy for early breast cancer and metastatic progression

BACKGROUND

This study aimed to investigate the distribution and changes of HER2 status in untreated tumours, in residual disease and in metastasis, and their long-term prognostic implications.

METHODS

This is a population-based cohort study of patients treated with neoadjuvant chemotherapy for breast cancer during 2007-2020 in the Stockholm-Gotland region which comprises 25% of the entire Swedish population. Information was extracted from the National Breast Cancer Registry and electronic patient charts to minimize data missingness and misclassification.

RESULTS

In total, 2494 patients received neoadjuvant chemotherapy, of which 2309 had available pretreatment HER2 status. Discordance rates were 29.9% between primary and residual disease (kappa = 0.534), 31.2% between primary tumour and metastasis (kappa = 0.512) and 33.3% between residual disease to metastasis (kappa = 0.483). Adjusted survival curves differed between primary HER2 0 and HER2-low disease (p < 0.001), with the former exhibiting an early peak in risk for death which eventually declined below the risk of HER2-low. Across all disease settings, increasing the number of biopsies increased the likelihood of detecting HER2-low status.

CONCLUSION

HER2 status changes during neoadjuvant chemotherapy and metastatic progression, and the long-term behaviours of HER2 0 and HER2-low disease differ, underscoring the need for obtaining tissue biopsies and for extended follow-up in breast cancer studies.

Utility of human epidermal growth factor 2 heterogeneity as a prognostic factor in triple-negative breast cancer

In some cases of human epidermal growth factor 2 (HER2)-negative breast cancer, including triple-negative breast cancer, HER2 expression is sporadically and strongly upregulated, a condition known as HER2 heterogeneity. We investigated the clinicopathological features of patients with HER2 heterogeneity in triple-negative breast cancers treated with neoadjuvant chemotherapy. Thirty-nine patients with triple-negative breast cancer who had undergone preoperative chemotherapy participated in this study. To assess for HER2 heterogeneity, we used dual in situ hybridization slides. We evaluated the association between HER2 heterogeneity and clinicopathological factors such as rates of pathologic complete response (pCR) and of recurrence-free survival. Of the 39 patients, 15 (38.5%) had cancers with HER2 heterogeneity. The pCR rates were 13.3% among patients with HER2 heterogeneity and 20.8% among those with HER2 nonheterogeneity, but the difference was not significant. The recurrence-free survival rate was significantly lower in patients with HER2 heterogeneity than in those without (P = 0.025). HER2 heterogeneity is a significant predictor of poor prognosis in patients with triple-negative breast cancer treated with neoadjuvant chemotherapy.

Kaiser score diagnosis of breast MRI lesions: Factors associated with false-negative and false-positive results

PURPOSE

We sought factors associated with false-negative and false-positive results in the diagnosis of breast lesions using the Kaiser score (KS) on breast magnetic resonance imaging (MRI).

METHODS

We retrospectively analyzed 1058 patients with 1058 breast lesions who underwent preoperative breast MRI with successful histopathologic results. Two radiologists assessed each lesion according to KS criteria, and clinicopathologic features and MRI findings were analyzed. Multivariate regression analysis was conducted to identify factors associated with false-negative and false-positive KS results.

RESULTS

Of the 1058 lesions, 859 were malignant and 199 were benign. Particularly high misdiagnosis rates were observed for intraductal papilloma, inflammatory lesion, and mucinous carcinoma. For breast cancer, KS yielded 821 (95.6 %) true-positive and 38 (4.4 %) false-negative results. Multivariate analysis showed that smaller lesion size (≤1 cm) (OR, 3.698; 95 %CI, 1.430-9.567; p = 0.007), absence of ipsilateral breast hypervascularity (OR, 3.029; 95 %CI, 1.370-6.693; p = 0.006), and presence of hyperintensity on T2WI (OR, 2.405; 95 %CI, 1.121-5.162; p = 0.024) were significantly associated with false-negative breast cancer results. For benign lesions, KS yielded 141 (70.9 %) true-negative and 58 (29.1 %) false-positive results. Multivariate regression analysis revealed that non-mass enhancement lesions (OR, 4.660; 95 %CI, 2.018-10.762; p＜0.001), moderate/high background parenchymal enhancement (OR, 2.402; 95 %CI, 1.180-4.892; p = 0.016), and the presence of hyperintensity on T2WI (OR, 2.986; 95 %CI, 1.386-6.433; p = 0.005) were significantly associated with false-positive KS results.

CONCLUSION

Several clinicopathologic and MRI features influence the accuracy of KS diagnosis. Understanding these factors may facilitate appropriate use of KS and guide alternative diagnostic approaches, ultimately improving diagnostic accuracy in the evaluation of breast lesions.

Real-world Outcomes of Dual HER2 Blockade Therapy in Metastatic HER2-Positive Breast Cancer: from Induction to Maintenance

BACKGROUND AND OBJECTIVE

Dual human epidermal growth factor receptor 2 (HER2) blockade with trastuzumab and pertuzumab combined with taxane-based chemotherapy (Cht) has been the standard first-line treatment for HER2-positive metastatic breast cancer (mBC) for years, due to the impressive results of the CLEOPATRA study. Real-world (RW) studies have become critical for assessing treatment effectiveness and safety in real-life circumstances. The aim of this study was to analyze the treatment outcomes of first-line therapy for HER2-positive mBC in RW clinical practice, specifically focusing on the use of maintenance endocrine therapy (ET) in hormone receptor positive (HR-positive) patients.

METHODS

This retrospective analysis included 106 HER2-positive mBC patients treated with trastuzumab and pertuzumab combined with taxane-based Cht from October 2015 to December 2020 at the University Hospital Centre Zagreb.

RESULTS

At a median follow-up of 30 months, median progression-free survival (PFS) was 25 months for the total population (95% confidence interval [CI] 16 - not analyzed). Patients with de novo mBC had longer median PFS than patients with recurrent disease (not reached vs. 18 months; hazard ratio 1.99; 95% CI 0.69-3.64, p<0.022). Age, hormone receptor positivity, visceral involvement, number of Cht cycles and previous adjuvant trastuzumab did not impact PFS. Most HR-positive patients (N=55, 88.7%) received maintenance ET after induction Cht.

CONCLUSION

This retrospective study provides additional data on patient characteristics, treatment and outcomes of RW HER2-positive mBC patients treated with pertuzumab and trastuzumab as first-line therapy. In our institution, maintenance ET after induction Cht has become standard clinical practice.

External Quality Assurance Helps Improve Infrastructure for Testing Breast Biomarkers Across a Lower- and Middle-Income Country: Our Experience With Breast Biomarker Testing in the National Cancer Grid External Quality Assurance System in India

CONTEXT.—

Biomarkers in breast cancer need strict monitoring given their role in patient management.

OBJECTIVE.—

To study the impact that regular participation in the National Cancer Grid (NCG) external quality assurance (EQA) system has on concordance rates for biomarkers in breast carcinoma.

DESIGN.—

Tissue microarrays (TMAs) containing breast carcinomas were circulated to participating laboratories that performed immunohistochemistry for breast biomarkers. The returned TMAs were then assessed for test concordance.

RESULTS.—

A total of 105 laboratories participated in the estrogen receptor (ER) and progesterone receptor (PR) EQA system cycles, and 99 centers participated in the human epidermal growth factor 2 (HER2) EQA system. In the ER EQA in the first cycle only 1 laboratory had a 100% concordance rate, which improved to 59 of 77 (76.6%) and 85 of 97 (87.6%) in the fourth and fifth cycles, respectively. In the PR EQA the 100% pass rate jumped from zero to 52 of 76 (68.4%) in the fourth cycle and 86 of 97 (88.6%) in the last cycle. For HER2 EQA, the 100% pass rates were seen in 7 of 23 laboratories (30.4%) in the first cycle, 49 of 78 laboratories (62.8%) in the fourth cycle, and 48 of 94 laboratories (51.1%) in fifth cycle of EQA. Centers that participated in the NCG EQA system for a longer period often changed testing methodology, with consequent improvement in their laboratory concordance rates. An increasing trend for the use of automated platforms and of the US Food and Drug Administration-approved antibody for HER2 testing was observed.

CONCLUSIONS.—

Our experience demonstrates that laboratory performance improves with participation in an EQA system even in less perfect settings, and this drives the placement of more proficient practices across the country.

Prognostic factors of patients with human epidermal growth factor receptor 2-positive breast cancer following neoadjuvant therapy: Development and validation of a predictive nomogram

OBJECTIVE

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer exhibits an aggressive phenotype and poor prognosis. The application of neoadjuvant therapy (NAT) in patients with breast cancer can significantly reduce the risks of disease recurrence and improve survival. By integrating different clinicopathological factors, nomograms are valuable tools for prognosis prediction. This study aimed to assess the prognostic value of clinicopathological factors in patients with HER2-positive breast cancer and construct a nomogram for outcome prediction.

METHODS

We retrospectively analyzed the clinicopathological data from 374 patients with breast cancer admitted to the Fourth Hospital of Hebei Medical University between January 2009 and December 2017, who were diagnosed with invasive breast cancer through preoperative core needle biopsy pathology, underwent surgical resection after NAT, and were HER2-positive. Patients were randomly divided into a training and validation set at a ratio of 7:3. Univariate and multivariate survival analyses were performed using Kaplan-Meier and Cox proportional hazards regression models. Results of the multivariate analysis were used to create nomograms predicting 3-, 5-, and 8-year overall survival (OS) rates. Calibration curves were plotted to test concordance between the predicted and actual risks. Harrell C-index and time-dependent receiver operating characteristic (ROC) curves were used to evaluate the discriminability of the nomogram prediction model.

RESULTS

All included patients were women, with a mean age of 50 ± 10.4 years (range: 26-72 years). In the training set, both univariate and multivariate analyses identified residual cancer burden (RCB) class, tumor-infiltrating lymphocytes(TILs), and clinical stage as independent prognostic factors for OS, and these factors were combined to construct a nomogram. The calibration curves demonstrated good concordance between the predicted and actual risks, and the C-index of the nomogram was 0.882 (95 % CI 0.863-0.901). The 3-, 5-, and 8-year areas under the ROC curve (AUCs) were 0.909, 0.893, and 0.918, respectively, indicating good accuracy of the nomogram. The calibration curves also demonstrated good concordance in the validation set, with a C-index of 0.850 (95 % CI 0.804-0.896) and 3-, 5-, and 8-year AUCs of 0.909, 0.815, and 0.834, respectively, which also indicated good accuracy.

CONCLUSION

The nomogram prediction model accurately predicted the prognostic status of post-NAT patients with breast cancer and was more accurate than clinical stage and RCB class. Therefore, it can serve as a reliable guide for selecting clinical treatment measures for breast cancer.

Integrated nomogram to predict HER2 expression in breast tumor: Clinical, Ultrasound, and Photoacoustic imaging approaches

BACKGROUND

HER2 is a key biomarker for breast cancer treatment and prognosis. Traditional assessment methods like immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are effective but costly and time-consuming. Our model incorporates these methods alongside photoacoustic imaging to enhance diagnostic accuracy and provide more comprehensive clinical insights.

MATERIALS AND METHODS

A total of 301 breast tumors were included in this study, divided into HER2-positive (3+ or 2+ with gene amplification) and HER2-negative (below 3+ and 2+ without gene amplification) groups. Samples were split into training and validation sets in a 7:3 ratio. Statistical analyses involved t-tests, chi-square tests, and rank-sum tests. Predictive factors were identified using univariate and multivariate logistic regression, leading to the creation of three models: ModA (clinical factors only), ModB (clinical plus ultrasound factors), and ModC (clinical, ultrasound, and photoacoustic imaging-derived oxygen saturation (SO2)).

RESULTS

The area under the curve (AUC) for ModA was 0.756 (95 % CI: 0.69-0.82), ModB increased to 0.866 (95 % CI: 0.82-0.91), and ModC showed the highest performance with an AUC of 0.877 (95 % CI: 0.83-0.92). These results indicate that the comprehensive model combining clinical, ultrasound, and photoacoustic imaging data (ModC) performed best in predicting HER2 expression.

CONCLUSION

The findings suggest that integrating clinical, ultrasound, and photoacoustic imaging data significantly enhances the accuracy of predicting HER2 expression. For personalised breast cancer treatment, the integrated model could provide a comprehensive and reproducible decision support tool.

An extensive immunohistochemical analysis of 290 ovarian adult granulosa cell tumors with 29 markers

The current knowledge about the immunohistochemical features of adult granulosa cell tumor (AGCT) is mostly limited to the "traditional" immunohistochemical markers of sex cord differentiation, such as inhibin, calretinin, FOXL2, SF1, and CD99. Knowledge about the immunohistochemical markers possibly used for predictive purpose is limited. In our study, we focused on the immunohistochemical examination of 290 cases of AGCT classified based on strict diagnostic criteria, including molecular testing. The antibodies used included 12 of the "diagnostic" antibodies already examined in previous studies, 10 antibodies whose expression has not yet been examined in AGCT, and 7 antibodies with possible predictive significance, including the expression of HER2, PD-L1, CTLA4, and 4 mismatch repair (MMR) proteins. The results of our study showed expression of FOXL2, SF1, CD99, inhibin A, calretinin, ER, PR, AR, CKAE1/3, and CAIX in 98%, 100%, 90%, 78%, 45%, 41%, 94%, 82%, 26%, and 9% of AGCT, respectively. GATA3, SATB2, napsin A, MUC4, TTF1, and CD44 were all negative. PTEN showed a loss of expression in 71% of cases and DPC4 in 4% of cases. The aberrant staining pattern (overexpression) of p53 was found in 1% (3/268) of cases, 2 primary tumors, and 1 recurrent case. Concerning the predictive markers, the results of our study showed that AGCT is microsatellite stable, do not express PD-L1, and are HER2 negative. The CTLA4 expression was found in almost 70% of AGCT tumor cells.

Best practices for achieving consensus in HER2-low expression in breast cancer: current perspectives from practising pathologists

AIMS

Human epidermal growth factor receptor 2 (HER2) expression is an important biomarker in breast cancer (BC). Most BC cases categorised as HER2-negative (HER2-) express low levels of HER2 [immunohistochemistry (IHC) 1+ or IHC 2+/in-situ hybridisation not amplified (ISH-)] and represent a clinically relevant therapeutic category that is amenable to targeted therapy using a recently approved HER2-directed antibody-drug conjugate. A group of practising pathologists, with expertise in breast pathology and BC biomarker testing, outline best practices and guidance for achieving consensus in HER2 IHC scoring for BC.

METHODS AND RESULTS

The authors describe current knowledge and challenges of IHC testing and scoring of HER2-low expressing BC and provide best practices and guidance for accurate identification of BCs expressing low levels of HER2. These expert pathologists propose an algorithm for assessing HER2 expression with validated IHC assays and incorporate the 2023 American Society of Clinical Oncology and College of American Pathologist guideline update. The authors also provide guidance on when to seek consensus for HER2 IHC scoring, how to incorporate HER2-low into IHC reporting and present examples of HER2 IHC staining, including challenging cases.

CONCLUSIONS

Awareness of BC cases that are negative for HER protein overexpression/gene amplification and the related clinical relevance for targeted therapy highlight the importance of accurate HER2 IHC scoring for optimal treatment selection.

HER2 amplification subtype intrahepatic cholangiocarcinoma exhibits high mutation burden and T cell exhaustion microenvironment

OBJECTIVE

This study aimed to establish a uniform standard for the interpretation of HER2 gene and protein statuses in intrahepatic cholangiocarcinoma (ICC). We also intended to explore the clinical pathological characteristics, molecular features, RNA expression and immune microenvironment of HER2-positive ICC.

METHODS

We analyzed a cohort of 304 ICCs using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) to identify HER2 status. Comprehensive analyses of the clinicopathological, molecular genetic, and RNA expression characterizations of ICCs with varying HER2 statuses were performed using next-generation sequencing. We further investigated the tumor microenvironment of ICCs with different HER2 statuses using IHC and multiplex immunofluorescence staining.

RESULTS

HER2/CEP17 ratio of ≥ 2.0 and HER2 copy number ≥ 4.0; or HER2 copy number ≥ 6.0 were setup as FISH positive criteria. Based on this criterion, 13 (4.27%, 13/304) samples were classified as having HER2 amplification. The agreement between FISH and IHC results in ICC was poor. HER2-amplified cases demonstrated a higher tumor mutational burden compared to non-amplified cases. No significant differences were observed in immune markers between the two groups. However, an increased density of CD8 + CTLA4 + and CD8 + FOXP3 + cells was identified in HER2 gene-amplified cases.

CONCLUSION

FISH proves to be more appropriate as the gold standard for HER2 evaluation in ICC. HER2 gene-amplified ICCs exhibit poorer prognosis, higher mutational burden, and T cell exhaustion and immune suppressed microenvironment.

Breast cancer during pregnancy of Luminal A type overexpressed CXCL13

Pregnancy-associated breast cancer has been increasing. In this study, we analyzed patients with breast cancer that occurred during pregnancy (PrBC) and compared their genetic profiles with those of patients with breast cancer that did not occur during pregnancy, within 1 year after childbirth nor during lactation (non-PrBC). We performed gene expression analyses of patients with PrBC and non-PrBC using microarrays and qRT-PCR. Microarray analysis showed that 355 genes were upregulated in the luminal-type PrBC group compared to those in the non-PrBC group. The C-X-C motif chemokine ligand 13 (CXCL13) gene was the most upregulated in the PrBC group compared to that in the non-PrBC group, especially in the luminal A-type (p = 0.016). This result was corroborated by the qRT-PCR analysis of microdissected cancer cells (p < 0.001). A negative correlation was observed between CXCL13 and estrogen receptor 1 (ESR1) mRNA expression levels in luminal A-type breast carcinoma (p < 0.001). Our results provide clues for a better understanding of breast cancer pathogenesis during pregnancy.

Real-world prevalence, treatment and survival of "high risk" early breast cancer, with mandatory testing of gBRCA1/2 mutation according to the OlympiA trial inclusion criteria: Data from a population-based registry

BACKGROUND

The results of the OlympiA study led to the approval of a PARP inhibitor (olaparib) as adjuvant treatment for early breast cancer (eBC) at high risk of relapse in patients with a germline BRCA1/2 mutation (gBRCAm). However, the proportion of patients in routine practice who meet the "high-risk" criteria applied in the OlympiA study, and for whom gBRCAm testing would now be mandatory, remains unknown.

PATIENTS AND METHODS

In this population-based study, we use unique data from the French specialized Côte d'Or Breast and Gynecological Cancer Registry, to assess the real-life proportion, and long-term prognosis of patients treated for eBC between 2005 and 2015 with standard treatment, and at "high risk" of relapse according to the OlympiA trial criteria.

RESULTS

We included 3483 patients treated for HER2-negative eBC (N = 380 with ER-, and N = 3103 with ER + tumor). We found N = 62 (1.8 %) patients with gBRCA1/2 mutations. A total of 494 patients (14.2 %) were classified as "high risk" according to the Olympia criteria; 55 % with ER-tumors, and 9.1 % with ER + tumors, respectively. Despite more intensive systemic treatments in "high risk" patients, 10-year overall survival was much worse in these "high risk" patients compared to the others: 60.1 % vs 83.8 % in ER-tumors, and 55.4 % vs 84.1 % in ER + tumors. Our estimates of net survival show an even greater difference.

CONCLUSION

This study provides real-life insights into the prevalence and prognosis of patients with high-risk eBC, in a context where the approval of adjuvant olaparib requires careful reorganization of care, so as not to overlook a patient with gBRCAm who could benefit from adjuvant olaparib.

Deciphering Breast Origin in Malignant Effusions: The Diagnostic Utility of an MGP, GATA-3, and TRPS-1 Immunocytochemical Panel

INTRODUCTION

Defining the origin of metastatic cancer is crucial for establishing an optimal treatment strategy, especially when obtaining sufficient tissue from secondary malignancies is limited. While cytological examination is often used in this diagnostic setting, morphologic analysis alone often fails to differentiate metastases derived from the breast from other primaries. The hormone receptor, human epidermal growth factor receptor-2, gross cystic disease fluid protein 15, and mammaglobin immunohistochemistry are often used to diagnose metastatic breast cancer. However, their effectiveness decreases in estrogen receptor (ER)-negative breast cancers, including the triple-negative breast cancer (TNBC) subtype.

METHODS

We conducted a comprehensive evaluation of GATA-binding protein 3 (GATA-3), trichorhinophalangeal syndrome type 1 (TRPS-1), and Matrix Gla Protein (MGP) immunochemistry across 140 effusion cytology specimens with metastatic adenocarcinoma derived from various primaries, including the breast, colon, pancreaticobiliary, lung, tubo-ovarian, and stomach.

RESULTS

The expression rates of these immunomarkers were significantly higher in metastatic cancers originating from the breast than other primaries. In TNBC, TRPS-1 (80.00%) and MGP (65.00%) exhibited higher positivity rates compared to GATA-3 (40.00%). Additionally, our data suggest that an immunohistochemical panel comprising MGP, GATA-3, and TRPS-1 significantly enhances the detection of metastatic breast cancer in effusion cytology specimens, including TNBC in particular. When considering dual-marker positivity, the diagnostic accuracy was found to be 89.29% across all breast cancer subtypes and 92.93% for TNBC.

CONCLUSIONS

MGP appears to be a robust marker for identifying metastatic breast cancer in malignant effusions, especially TNBC. MGP notably enhances diagnostic accuracy when incorporated together with GATA-3 and TRPS-1 in an immunohistochemical panel.

Predicting Pathological Characteristics of HER2-Positive Breast Cancer from Ultrasound Images: a Deep Ensemble Approach

The objective is to evaluate the feasibility of utilizing ultrasound images in identifying critical prognostic biomarkers for HER2-positive breast cancer (HER2 + BC). This study enrolled 512 female patients diagnosed with HER2-positive breast cancer through pathological validation at our institution from January 2016 to December 2021. Five distinct deep convolutional neural networks (DCNNs) and a deep ensemble (DE) approach were trained to classify axillary lymph node involvement (ALNM), lymphovascular invasion (LVI), and histological grade (HG). The efficacy of the models was evaluated based on accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), receiver operating characteristic (ROC) curves, areas under the ROC curve (AUCs), and heat maps. DeLong test was applied to compare differences in AUC among different models. The deep ensemble approach, as the most effective model, demonstrated AUCs and accuracy of 0.869 (95% CI: 0.802-0.936) and 69.7% in LVI, 0.973 (95% CI: 0.949-0.998) and 73.8% in HG, thus providing superior classification performance in the context of imbalanced data (p < 0.05 by the DeLong test). On ALNM, AUC and accuracy were 0.780 (95% CI: 0.688-0.873) and 77.5%, which were comparable to other single models. The pretreatment US-based DE model could hold promise as a clinical guidance for predicting pathological characteristics of patients with HER2-positive breast cancer, thereby providing benefit of facilitating timely adjustments in treatment strategies.