Clinical-pathologic characteristics and response to neoadjuvant chemotherapy in triple-negative low Ki-67 proliferation (TNLP) breast cancers

Mucinous Cystadenocarcinomas of the Breast Exhibit Heterogeneous Genomic Profile as Triple Negative Breast Cancer, Harbor Alterations in PIK3CA, PTEN, AKT1, and GNAS Genes, and May Not Be Indolent

Mucinous cystadenocarcinoma of the breast is an exceedingly rare entity with less than 40 tumors reported to date. It is classified as a special subtype of breast carcinoma which exhibits low-grade indolent behavior despite having a triple-negative phenotype. Awareness of this rare tumor is essential to avoid misinterpreting it as a routine mucinous (colloid) carcinoma of the breast or metastasis from a nonmammary mucinous carcinoma. Though the clinical, histological, and immunohistochemical features of breast mucinous cystadenocarcinoma have been described thoroughly, data on molecular features remains scarce. Herein, we present 3 patients with mucinous cystadenocarcinoma, highlighting the molecular features in 2 patients and discussing the literature in this regard. Additionally, we report that these tumors have the potential for short-term recurrence despite complete surgical excision, and they therefore should probably be treated as any other triple-negative breast cancer (TNBC) with careful consideration of other factors such as patient's age, tumor size, nodal stage, and tumor grade. Review of the literature on this rare tumor together with findings from the current report suggests that MCAs at the molecular level are similar to TNBC, with frequent recurring variants in PI3K pathway genes, including PIK3CA, PTEN, and AKT1 genes. We report here for the first time the presence of GNAS variants in mucinous cystadenocarcinoma. This information could be useful to offer targeted treatment against PIK3CA and AKT1 in patients with this rare tumor.

Neoadjuvant Chemotherapy Response in Triple-Negative Apocrine Carcinoma: Comparing Apocrine Morphology, Androgen Receptor, and Immune Phenotypes

CONTEXT.—

Apocrine differentiation and androgen receptor (AR) positivity represent a specific subset of triple-negative breast cancer (TNBC) and are often considered potential prognostic or predictive factors.

OBJECTIVE.—

To evaluate the response of TNBC to neoadjuvant chemotherapy (NAC) and to assess the impact of apocrine morphology, AR status, Ki-67 labeling index (Ki-67LI), and tumor-infiltrating lymphocytes (TILs).

DESIGN.—

A total of 232 TNBC patients who underwent NAC followed by surgical resection in a single institute were analyzed. The study evaluated apocrine morphology and AR and Ki-67LI expression via immunohistochemistry from pre-NAC biopsy samples. Additionally, pre-NAC intratumoral TILs and stromal TILs (sTILs) were quantified from biopsies using a deep learning model. The response to NAC after surgery was assessed based on residual cancer burden.

RESULTS.—

Both apocrine morphology and high AR expression correlated with lower Ki-67LI (P < .001 for both). Apocrine morphology was associated with lower postoperative pathologic complete response (pCR) rates after NAC (P = .02), but the difference in TILs between TNBC cases with and without apocrine morphology was not statistically significant (P = .09 for sTILs). In contrast, AR expression did not significantly affect pCR (P = .13). Pre-NAC TILs strongly correlated with postoperative pCR in TNBCs without apocrine morphology (P < .001 for sTILs), whereas TNBC with apocrine morphology demonstrated an indeterminate trend (P = .82 for sTILs).

CONCLUSIONS.—

Although TIL counts did not vary significantly based on apocrine morphology, apocrine morphology itself was a more reliable predictor of NAC response than AR expression. Consequently, although apocrine morphology is a rare subtype of TNBC, its identification is clinically important.

Proliferative Markers in Breast Cancer and Chemotherapy Implications: A Comprehensive Review

Background and Aims

Breast cancer is the most common cancer and a leading cause of cancer-related death among women globally. Determining which patients will benefit from chemotherapy remains challenging. Proliferative markers such as Ki-67, mini chromosome maintenance (MCM) proteins, and proliferating cell nuclear antigen (PCNA) offer valuable insights into tumor growth and treatment response. This review evaluates their clinical roles, with a focus on chemotherapy implications and emerging digital pathology techniques for marker quantification.

Methods

A narrative review was conducted by searching PubMed, Scopus, and Google Scholar for studies related to Ki-67, MCM, PCNA, breast cancer, and chemotherapy. Studies were thematically categorized into five areas. A bibliometric analysis of publications from 2000 to April 2023 was performed using the Bibliometrix R package and VOSviewer to assess research trends and thematic evolution.

Results

Eighty studies were included in the narrative synthesis. Ki-67 is the most commonly used marker, particularly useful in predicting response to neoadjuvant chemotherapy (NAC). MCM proteins show promise for identifying proliferative potential across tumor grades, while PCNA is associated with aggressive tumor features and poor prognosis. Post-chemotherapy changes in Ki-67 levels are linked to survival outcomes. Bibliometric analysis revealed a shift in research focus from basic mechanisms to clinical applications and digital quantification.

Conclusion

Proliferative markers play an essential role in breast cancer management. Ki-67 remains a key predictor of chemotherapy response, while MCM and PCNA offer complementary prognostic insights. Integration of these markers with digital pathology and AI-driven tools may enhance diagnostic accuracy and personalized treatment strategies. Standardization of assessment methods is crucial for broader clinical application.

The prognostic value of changes in Ki67 following neoadjuvant chemotherapy in residual triple-negative breast cancer: a Swedish nationwide registry-based study

PURPOSE

To evaluate the prognostic significance of changes in pre- and post-neoadjuvant chemotherapy (NACT) Ki67 in patients with primary invasive triple-negative breast cancer (TNBC).

METHODS

Population-based registry data were retrieved for patients diagnosed with TNBC between 2007 and 2021 (n = 9262). Multivariable Cox regression analysis was performed for disease-specific survival (DSS) and overall survival (OS) adjusted for age and residual disease in the breast and nodes (RDBN).

RESULTS

Of the 1777 TNBC patients receiving NACT, 54 achieved pathologic complete response (pCR) and 755 had residual disease. Most patients were overweight with stage II disease (78%), grade 3 tumors (53%), and RDBN score 3 (42%). Compared to baseline, tumor size (30 vs. 15 mm; P < 0.0001) and Ki67 levels (63% vs. 48%; P < 2.2e - 16) generally decreased after NACT. Although only 5% of samples increased in size, Ki67 levels often remained unchanged (75%) or increased (0.9%) after treatment, respectively. However, 34% of patients discontinued treatment. Patients showing no changes in Ki67% had more unfavorable OS (P < 0.0001) and DSS (P = 0.00032), with significantly lower 5-year survival probabilities (OS: 66%; DSS: 78%) than those with decreased Ki67% (OS: 87%; DSS: 89%). All patients reaching pCR were alive 5 years after diagnosis. However, only the RDBN score was an independent predictor of survival in the multivariable analyses.

CONCLUSION

Ki67 often remained unchanged in TNBC patients treated with neoadjuvant chemotherapy, resulting in adverse clinical outcomes. These findings highlight the need for individualized treatment regimens and dynamic monitoring of TNBC patients with high Ki67 post-NACT.

Neoadjuvant chemotherapy response in androgen receptor-positive triple-negative breast cancer: potential predictive biomarkers and genetic alterations

BACKGROUND

The aim of the present study was to investigate whether the androgen receptor (AR) status affects the efficacy of neoadjuvant chemotherapy (NACT) in triple negative breast cancer (TNBC) patients, and to elucidate the predictive biomarkers and mutations associated with pathological complete response (pCR) in AR-positive TNBC patients.

METHODS

The current retrospective cohort included 226 TNBC patients who underwent NACT. AR and FOXC1 were assessed by immunohistochemistry on pretreatment biopsy specimens of 226 TNBC patients from 2018 to 2022. The clinicopathological features of AR-negative, AR < 10%, and AR ≥ 10% TNBC patients were analyzed to confirm the appropriate threshold. The response was evaluated in terms of pCR and Miller-Payne (MP) grade in the subsequent mastectomy or breast conservation samples. Next-generation sequencing (NGS) was utilized to further investigate the molecular characteristics of 44 AR-positive TNBC patients.

RESULTS

Among the 226 TNBC patients, compared with AR-negative and AR < 10% tumors (68.58%, 155/226), AR ≥ 10% TNBC patients (31.41%, 71/226) exhibited distinct clinicopathological features, while no significant difference was detected between those with AR-negative tumors and those with AR < 10% tumors. Thus, tumors with AR ≥ 10% expression were defined as having AR positive expression. The pCR rate of AR-positive TNBCs was lower than that of AR-negative TNBC patients (12.68% vs. 34.19%, p < 0.001). In TNBC, multivariate analysis demonstrated that FOXC1 was an independent predictor of pCR (p = 0.042), whereas AR was not. The pCR rate was higher in FOXC1 positive patients than in FOXC1 negative patients (34.44% vs. 3.13%, p < 0.001). In the AR-positive TNBC subgroup, patients with FOXC1 expression had lower AR expression, higher Ki-67 expression, and higher histological grade. Compared with AR-positive TNBC patients who achieved pCR, the non-pCR patients had a greater percentage of mutations in genes involved in the PI3K/AKT/mTOR pathway.

CONCLUSIONS

The current study indicated that the AR-positive TNBC is correlated with lower rates of pCR after NACT. The expression of FOXC1 in TNBC patients and AR-positive TNBC patients could be utilized as a predictive marker for the efficacy of NACT. The present study provides a rationale for treating these non-pCR AR-positive TNBC tumors with PI3K/AKT/mTOR inhibitors.

Association of tumor-infiltrating lymphocytes with clinical outcomes in patients with triple-negative breast cancer receiving neoadjuvant chemotherapy: a systematic review and meta-analysis

OBJECTIVE

Triple-negative breast cancer (TNBC) presents a clinical challenge as an aggressive tumor, correlated with unfavorable prognosis. Tumor-infiltrating lymphocytes (TILs) have garnered interest as a potential prognostic biomarker. However, the disparity in outcomes between varying TILs rates remains inadequately explored.

METHODS

PubMed, Scopus, Web of Science, and Cochrane databases were searched for studies about the prognostic value of TILs in patients with TNBC receiving neoadjuvant chemotherapy. The hazard ratios (HRs) or odds ratios (ORs) were computed for binary endpoints, with 95% confidence intervals (CIs).

RESULTS

Twenty-nine studies were included, involving a population of six thousand one hundred sixty-one (80.41%) with TNBC. The cut-off TILs value ranged from 10 to 60%, with 50% being the most related value. Compared with the low-TIL expression group, the disease-free survival (DFS) (HR 0.71; 95% CI 0.61-0.82; p < 0.00001) and overall survival (OS) (HR 0.76; 95% CI 0.63-0.90; p = 0.002) rates showed significant improvement with higher TIL infiltrations. In the subgroup analyses of the lymphocyte subtypes CD4 + and CD8 + , there was statistical significance favoring higher TILs rates in both subtypes, each associated with improved DFS (HR 0.48; 95% CI 0.33-0.71; p = 0.0002) and OS (HR 0.53; 95% CI 0.36-0.78; p = 0.001), regardless of which cell subtype was predominantly infiltrated. The complete pathological response analysis showed better rates for the higher TIL group than the control for both the TIL (OR 1.29; 95% CI 1.13-1.48; p = 0.0003) and Ki-67 (OR 2.74; 95% CI 2.01-3.73; p < 0.00001) analyses.

CONCLUSION

Higher expressions of TILs in patients with TNBC were associated with improved significantly DFS, OS, and pCR outcomes.

Unraveling complexity and leveraging opportunities in uncommon breast cancer subtypes

Special histologic subtypes of breast cancer (BC) exhibit unique phenotypes and molecular profiles with diagnostic and therapeutic implications, often differing in behavior and clinical trajectory from common BC forms. Novel methodologies, such as artificial intelligence may improve classification. Genetic predisposition plays roles in a subset of cases. Uncommon BC presentations like male, inflammatory and pregnancy-related BC pose challenges. Emerging therapeutic strategies targeting genetic alterations or immune microenvironment are being explored.

Targeting low-risk triple-negative breast cancer: a review on de-escalation strategies for a new era

Triple-negative breast cancer (TNBC) is a subtype of breast cancer lacking estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression. Comprising 15-20% of breast cancers, TNBC is typically high-grade, affects younger women, and has a poor prognosis. However, TNBC is heterogeneous, encompassing different molecular subtypes and histological types with distinct molecular drivers, prognoses, and treatment responses. Among these, a subset of low-risk diseases associated with a lower risk of recurrence led to the exploration of de-escalation strategies. This review presents the clinicopathological characteristics of special TNBC with a better prognosis that could be spared from aggressive systemic treatment. We searched the PubMed database for articles that could support treatment de-escalation using the keywords "early-stage", "TNBC", and "low-risk". This article addresses four subgroups of low-risk TNBC: special histological types, tumors with high tumor-infiltrating lymphocytes (TILs), low Ki-67 levels, and early-stage tumors that achieved pathological complete response (pCR). The discussion explores the optimization of treatment options ranging from the omission of any systemic treatment to anthracycline-free possibilities and/or immunotherapies. Identifying these tumors can help personalize treatment, reduce costs and unnecessary toxicity, and contribute to a better quality of life for patients with favorable prognoses. Further studies should explore reliable biomarkers to identify these low-risk diseases precisely.

Multiomics and single-cell sequencings reveal the specific biological characteristics of low Ki-67 triple-negative breast cancer

Background

Triple-negative breast cancer (TNBC) displays high heterogeneity. The majority of TNBC cases are characterized by high Ki-67 expression. TNBC with low Ki-67 expression accounts for only a small fraction of cases and has been relatively less studied.

Methods

This study analyzed a large single-center multiomics TNBC data set, combined with a single-cell data set. The clinical, genomic, and metabolic characteristics of patients with low Ki-67 TNBC were analyzed.

Results

The clinical and pathological characteristics were analyzed in 2217 TNBC patients. Low Ki-67 TNBC was associated with a higher patient age at diagnosis, a lower proportion of invasive ductal carcinoma, increased alterations in the PI3K-AKT-mTOR pathway, upregulated lipid metabolism pathways, and enhanced infiltration of M2 macrophages. High Ki-67 TNBC exhibited a higher prevalence of TP53 gene mutations, elevated nucleotide metabolism, and increased infiltration of M1 macrophages.

Conclusions

We identified specific genomic and metabolic characteristics unique to low Ki-67 TNBC, which have implications for the development of precision therapies and patient stratification strategies.

Immunohistochemical Profile of Triple-Negative Breast Cancers: SOX10 and AR Dual Negative Tumors Have Worse Outcomes

Triple-negative breast cancer (TNBC) refers to an estrogen receptor-negative, progesterone receptor-negative, and HER2-negative breast cancer. Although accepted as a clinically valid category, TNBCs are heterogeneous at the histologic, immunohistochemical, and molecular levels. Gene expression profiling studies have molecularly classified TNBCs into multiple groups, but the prognostic significance is unclear except for a relatively good prognosis for the luminal androgen receptor subtype. Immunohistochemistry (IHC) has been used as a surrogate for basal and luminal subtypes within TNBC, but prognostication of TNBC using IHC is not routinely performed. We aimed to study immunophenotypic correlations in a well-annotated cohort of consecutive TNBCs, excluding postneoadjuvant chemotherapy cases. Tissue microarrays were constructed from a total of 245 TNBC cases. IHC stains were performed and consisted of luminal (AR and INPP4B), basal (SOX10, nestin, CK5, and EGFR), and diagnostic (GCDFP15, mammaglobin, GATA3, and TRPS1) markers. Survival analysis was performed to assess the significance of clinical-pathologic variables including age, histology, grade, lymphovascular invasion, Nottingham prognostic index category, American Joint Committee on Cancer (AJCC) stage, stromal tumor-infiltrating lymphocytes at 10% increment, CD8+ T-cell count, Ki-67 index, PD-L1 status, and chemotherapy along with the results of IHC markers. Apocrine tumors show prominent reactivity for luminal markers and GCDFP15, whereas no special-type carcinomas are often positive for basal markers. TRPS1 is a sensitive marker of breast carcinoma but shows low or no expression in apocrine tumors. High AJCC stage, lack of chemotherapy, and dual SOX10/AR negativity are associated with worse outcomes on both univariable and multivariable analyses. Lymphovascular invasion and higher Nottingham prognostic index category were associated with worse outcomes on univariable but not multivariable analysis. The staining for IHC markers varies based on tumor histology, which may be considered in determining breast origin. Notably, we report that SOX10/AR dual negative status in TNBC is associated with a worse prognosis along with AJCC stage and chemotherapy status.

Triple-negative breast cancer: from none to multiple therapeutic targets in two decades

Triple-negative breast cancers (TNBCs) are more likely to occur in younger patients and have a poor prognosis. They are highly heterogeneous tumors consisting of different molecular subtypes. The only common characteristic among them is the absence of targets for endocrine therapy and human epidermal growth factor receptor 2 (HER2) blockade. In the past two decades, there has been an increased understanding of these tumors from a molecular perspective, leading to their stratification according to new therapeutic strategies. TNBC has ushered breast carcinomas into the era of immunotherapy. The higher frequency of germline BRCA mutations in these tumors enables targeting this repair defect by drugs like PARP inhibitors, resulting in synthetic lethality in neoplastic cells. Additionally, we have the identification of new molecules to which this generation of smart drugs, such as antibody-drug conjugates (ADCs), are directed. In this review, we will discuss the trajectory of this knowledge in a systematic manner, presenting the molecular bases, therapeutic possibilities, and biomarkers.

Utility of TRPS1 immunohistochemistry in confirming breast carcinoma: Emphasis on staining in triple-negative breast cancers and gynecologic tumors

OBJECTIVES

Our aim was to explore the performance of TRPS1 as an immunohistochemical diagnostic marker; find the optimal conditions for its use in breast carcinomas, especially triple-negative breast cancers (TNBCs); and compare its results in carcinomas of a select few organ sites, with an emphasis on gynecologic tumors.

METHODS

Tissue microarrays from breast carcinomas (n = 197), endometrial adenocarcinomas (n = 69), ovarian tumors (n = 250), vulvar squamous cell carcinomas (n = 97), pancreatic ductal adenocarcinomas (n = 20), and gastric adenocarcinomas (n = 12) were stained with TRPS1 using 2 different conditions (protocol 1: high pH; protocol 2: low pH). Breast carcinomas consisted of hormone receptor (HR)-positive/ERBB2 (formerly HER2 or HER2/neu)-negative (n = 53) samples, HR-positive/ERBB2-positive (n = 6) samples, and TNBCs (n = 138).

RESULTS

Comparing TRPS1 results in breast carcinomas vs tumors from other organ sites, the sensitivity of TRPS1 was 91% and 87%, respectively, while the specificity was 66% and 74% for protocol 1 and 2, respectively. For TNBCs vs gynecologic tumors, the sensitivity of TRPS1 was 89% and 85%, respectively, while the specificity was 65% and 73%, respectively.

CONCLUSIONS

TRPS1 stains approximately 90% of breast carcinomas but also up to 71% of endometrial carcinomas, albeit with a weaker median expression. Our data show that although TRPS1 is a highly sensitive marker for TNBCs, it is not as highly specific as previously reported.

Triple-negative Breast Carcinoma With Apocrine and Histiocytoid Features: A Clinicopathologic and Molecular Study of 18 Cases

Triple-negative breast cancer (TNBC) is a heterogenous group of tumors. Most TNBCs are high-grade aggressive tumors, but a minority of TNBCs are not high grade, with relatively indolent behavior and specific morphologic and molecular features. We performed a clinicopathologic and molecular assessment of 18 non-high-grade TNBCs with apocrine and/or histiocytoid features. All were grade I or II with low Ki-67 (≤20%). Thirteen (72%) showed apocrine features, and 5 (28%) showed histiocytoid and lobular features. In all, 17/18 expressed the androgen receptor, and 13/13 expressed gross cystic disease fluid protein 15. Four (22.2%) patients were treated with neoadjuvant chemotherapy, but none achieved a pathologic complete response. In all, 2/18 patients (11%) had lymph node metastasis at the time of surgery. None of the cases had a recurrence or disease-specific death, with an average follow-up time of 38 months. Thirteen cases were profiled by targeted capture-based next-generation DNA sequencing. Genomic alterations (GAs) were most significant for PI3K-PKB/Akt pathway (69%) genes, including PIK3R1 (23%), PIK3CA (38%), and PTEN (23%), and RTK-RAS pathway (62%) including FGFR4 (46%) and ERBB2 (15%). TP53 GA was seen in only 31% of patients. Our findings support those on high-grade TNBCs with apocrine and/or histiocytoid features as a clinicopathologic and genetically distinct subgroup of TNBC. They can be defined by features including tubule formation, rare mitosis, low Ki-67 (≤20%), triple-negative status, expression of androgen receptor and/or gross cystic disease fluid protein 15, and GA in the PI3K-PKB/Akt and/or RTK-RAS pathway. These tumors are not sensitive to chemotherapy but have favorable clinical behavior. Tumor subtype definitions are the first step to implementing future trial designs to select these patients.

Prediction of clinical response to neoadjuvant therapy in advanced breast cancer by baseline B-mode ultrasound, shear-wave elastography, and pathological information

Background

Neoadjuvant therapy (NAT) is the preferred treatment for advanced breast cancer nowadays. The early prediction of its responses is important for personalized treatment. This study aimed at using baseline shear wave elastography (SWE) ultrasound combined with clinical and pathological information to predict the clinical response to therapy in advanced breast cancer.

Methods

This retrospective study included 217 patients with advanced breast cancer who were treated in West China Hospital of Sichuan University from April 2020 to June 2022. The features of ultrasonic images were collected according to the Breast imaging reporting and data system (BI-RADS), and the stiffness value was measured at the same time. The changes were measured according to the Response evaluation criteria in solid tumors (RECIST1.1) by MRI and clinical situation. The relevant indicators of clinical response were obtained through univariate analysis and incorporated into a logistic regression analysis to establish the prediction model. The receiver operating characteristic (ROC) curve was used to evaluate the performance of the prediction models.

Results

All patients were divided into a test set and a validation set in a 7:3 ratio. A total of 152 patients in the test set, with 41 patients (27.00%) in the non-responders group and 111 patients (73.00%) in the responders group, were finally included in this study. Among all unitary and combined mode models, the Pathology + B-mode + SWE model performed best, with the highest AUC of 0.808 (accuracy 72.37%, sensitivity 68.47%, specificity 82.93%, P<0.001). HER2+, Skin invasion, Post mammary space invasion, Myometrial invasion and Emax were the factors with a significant predictive value (P<0.05). 65 patients were used as an external validation set. There was no statistical difference in ROC between the test set and the validation set (P>0.05).

Conclusion

As the non-invasive imaging biomarkers, baseline SWE ultrasound combined with clinical and pathological information can be used to predict the clinical response to therapy in advanced breast cancer.

AMACR Expression is a Potential Diagnostic Marker in Apocrine Lesions of Breast, and is Associated with High Histologic Grade and Lymph Node Metastases in Some Invasive Apocrine Breast Cancers

BACKGROUND

Carcinoma with apocrine differentiation (AC) is a subtype of breast carcinoma with apocrine features in >90% of the tumor. Molecular studies demonstrate AC has high expression of androgen receptor (AR) mRNA. Pure AC lack estrogen receptor (ER), progesterone receptor (PR), and express AR, with variable human epidermal growth factor 2 (HER2) status. Currently, in triple negative AC, no targetable therapies or specific diagnostic markers exist.

MATERIALS AND METHODS

α-Methylacyl CoA racemase (AMACR) expression was investigated as a marker of apocrine differentiation using a single-plex immunoperoxidase stain, and a novel AMACR/p63 dual stain in a subset of cases, across 1) benign apocrine lesions (apocrine metaplasia, adenosis) 2) apocrine DCIS (ADCIS), 3) AC/ invasive ductal carcinoma (IDC) with apocrine features, 4) non-apocrine triple negative breast cancer (TNBC) and 5) IDC, no special type. A sub-set of cases were evaluated by tissue microarray.

RESULTS

AMACR expression was increased in both AC and ADCIS, with minimal expression in benign breast tissue, TNBC and IDC, NST cases. In invasive cases, those with positive AMACR (>5% positivity) were significantly associated with higher histologic grade (P = .006), initial N stage (chi squared 0.044), and lack of ER or PR expression (both P < .001), with no correlation with overall survival. Analysis of TCGA breast cancer datasets revealed AMACR expression was significantly higher in molecularly defined apocrine carcinomas relative to basal and luminal subtypes. Moreover, high AMACR expression predicted worse relapse-free and distant-metastasis free survival, among both ER-/PR-/Her2- and ER-/PR-/Her2+ breast cancer cohorts (log-rank P = .081 and .00011, respectively).

CONCLUSION

AMACR represents a promising diagnostic and prognostic marker in apocrine breast lesions. Further study is needed to determine the biologic and clinical significance of this protein in AC.

Evaluation of treatment responses among subgroups of breast cancer patients receiving neoadjuvant chemotherapy

BACKGROUND

Breast MRIs are helpful for determining treatment plans, responses, and prospective survival analyses. In this retrospective cross-sectional study, we compared the preoperative MRI treatment response to neoadjuvant chemotherapy (NAC) administration with the postoperative pathological response in breast cancer patients.

MATERIALS AND METHODS

We analyzed data from 108 hospitalized patients receiving NAC between 2020 and 2022. We used MRI to evaluate the treatment response to NAC in patients with locally advanced breast cancers who had not received any prior treatment. We recorded the longest diameter of the primary tumor and the numbers of secondary tumors and axillary lymph nodes. In addition, we examined the correlation between the MRI response rate and pathological specimen results.

RESULTS

In our subgroup analyses, we found the best pathological response in patients with luminal B (Ki-67 index >14%) breast cancer and positivity for both hormone receptor and HER-2 markers. After comparing the pathological and radiological treatment responses in tumors and lymph nodes, the sensitivities were 90.3% for the pathological assessment and 42.8% for the radiological assessment, while the accuracies were 84.2% for the pathological assessment and 61.1% for the radiological assessment.

CONCLUSION

Using MRI techniques and sequence intervals and examining the histopathological characteristics of tumors may help increase the accuracy of the pathological complete response.

BluePrint breast cancer molecular subtyping recognizes single and dual subtype tumors with implications for therapeutic guidance

PURPOSE

BluePrint (BP) is an 80-gene molecular subtyping test that classifies early-stage breast cancer (EBC) into Basal, Luminal, and HER2 subtypes. In most cases, breast tumors have one dominant subtype, representative of a single activated pathway. However, some tumors show a statistically equal representation of more than one subtype, referred to as dual subtype. This study aims to identify and examine dual subtype tumors by BP to understand their biology and possible implications for treatment guidance.

METHODS

The BP scores of over 15,000 tumor samples from EBC patients were analyzed, and the differences between the highest and the lowest scoring subtypes were calculated. Based upon the distribution of the differences between BP scores, a threshold was determined for each subtype to identify dual versus single subtypes.

RESULTS

Approximately 97% of samples had one single activated BluePrint molecular subtype, whereas ~ 3% of samples were classified as BP dual subtype. The most frequently occurring dual subtypes were the Luminal-Basal-type and Luminal-HER2-type. Luminal-Basal-type displays a distinct biology from the Luminal single type and Basal single type. Burstein's classification of the single and dual Basal samples showed that the Luminal-Basal-type is mostly classified as 'luminal androgen receptor' and 'mesenchymal' subtypes, supporting molecular evidence of AR activation in the Luminal-Basal-type tumors. Tumors classified as Luminal-HER2-type resemble features of both Luminal-single-type and HER2-single-type. However, patients with dual Luminal-HER2-type have a lower pathological complete response after receiving HER2-targeted therapies in addition to chemotherapy in comparison with patients with a HER2-single-type.

CONCLUSION

This study demonstrates that BP identifies tumors with two active functional pathways (dual subtype) with specific transcriptional characteristics and highlights the added value of distinguishing BP dual from single subtypes as evidenced by distinct treatment response rates.