Adjuvant chemotherapy in small node-negative triple-negative breast cancer

Unveiling the paradigm shift: systemic treatment strategies in small, node-negative breast cancer

The implementation of screening mammography has significantly altered the size distribution of breast tumors, with approximately 20% of newly diagnosed breast cancers measuring 10 mm or smaller with node-negative disease (T1aN0 and T1bN0). The management of these early-stage breast cancers remains a subject of debate. Historically, patients with T1aN0 and T1bN0 breast cancer have been excluded from adjuvant chemotherapy trials due to their excellent prognosis, with reported 10-year disease-specific survival rates exceeding 90%. However, the optimal treatment strategy for this subgroup of patients continues to be controversial, as the potential benefits of adjuvant chemotherapy must be carefully weighed against the risks of overtreatment. In this review, we summarize current evidence on outcomes and treatment strategies, highlight gaps in the literature, and provide future perspectives on the management of T1aN0 and T1bN0 breast cancer, according to immunohistochemical subtypes.

Clinical Relevance of Immunohistochemical Subtypes in Early-Stage, Lymph Node-negative Breast Cancer. Results of a Large Cohort Study

AIMS

This study aimed to provide the association of immunohistochemical (IHC) subtypes of early-stage, lymph node-negative breast cancer with clinical outcomes. The relevance of adjuvant systemic therapy (AST) with respect to triple-negative cancers was given special attention.

MATERIALS AND METHODS

We used the data of 1,959 breast-conserving therapies (BCTs) in 1,861 women diagnosed with early-stage unilateral, lymph node-negative breast cancer treated between 2004 and 2015.

RESULTS

Overall, IHC subtypes were not associated with disease-specific survival (DSS) or overall survival (OS) in multivariate analyses. Looking at the influence of AST, administered according to current guidelines, we noted that triple-negativity compared to luminal A demonstrated a better DSS (hazard ratio [HR]: 0.4, 95% confidence interval [CI]: 0.1-1.1). For those without AST, outcomes for all subtypes did not differ. Difference in outcome of triple-negative tumours for without and with AST was mainly due the presence of patients bearing histological grade 3 cancers in those without AST.

CONCLUSION

In early-stage, lymph node-negative breast cancer treated with BCT and AST, according to existing guidelines, triple-negativity demonstrated a better outcome in DSS. However, for those without AST, no differences were seen in outcome between the various subtypes.

Predictive Value of Excision Repair Cross Complementation Group 1 (ERCC1) by Immunohistochemistry for Determining Neoadjuvant Chemotherapy Response in Triple-Negative Breast Cancers

Introduction: Triple-negative breast cancers (TNBCs) constitute a significant proportion of breast cancers in Pakistan. Owing to the lack of expression of hormone (estrogen/progesterone) receptor and human epidermal growth factor receptor 2 (HER2neu), treatment options for TNBCs are limited. Therefore, it is important to identify markers that predict response to chemotherapy in these patients. Previous studies have demonstrated that the excision repair cross complementation group 1 (ERCC1) protein can successfully augur the response to chemotherapy in cancer; however, data related to TNBCs, particularly in Pakistan, are limited. Therefore, in this study, we evaluated the role of ERCC1 in predicting the response to neoadjuvant chemotherapy in patients with TNBCs. Methods: This cross-sectional study was conducted at the Liaquat National Hospital, Histopathology Department, between January 2019 and June 2023. A total of 132 biopsy-proven cases of breast cancer that were negative for estrogen receptor (ER), progesterone receptor (PR), and HER/2neu and were administered neoadjuvant chemotherapy before surgery were included in the study. ERCC1 immunohistochemical (IHC) staining was performed on prechemotherapy needle biopsies. The results were scored semiquantitatively by assessing the average intensity on a scale of 0-3 (0, no staining; 1, weak nuclear staining; 2, intermediate nuclear staining; and 3, strong nuclear staining) and the proportion of tumor cells showing positive nuclear staining. The intensity and proportion scores were then multiplied to give a score that was divided by 100 to give an overall score, and scores equal to or higher than 1.0 were considered positive. Neoadjuvant chemotherapy response was categorized as pathological complete response (pCR) when no residual invasive breast carcinoma was found on the postneoadjuvant chemotherapy excision specimen and as pathological partial response (pPR) when residual cancer cells were present in admixed chemotherapy-related changes. The residual cancer burden (RCB) was calculated using the MD Anderson RCB calculator. The association between ERCC1 expression and the chemotherapy response/RCB class was determined. Results: We found that 90.9% (n = 120) of TNBC cases expressed ERCC1, whereas pCR was noted in 24 (18.2%) cases. A significant association was observed between ERCC1 expression and pCR. Cases with negative ERCC1 expression had a significantly higher frequency of pCR (66.7%) than those with positive ERCC1 expression (13.3%). Additionally, the ERCC1-positive group showed a higher frequency of RCB classes II (36.7%) and III (43.3%) than the ERCC1-negative group (RCB II: 25%; RCB III: 0%). Moreover, positive ERCC1 expression was associated with higher nodal (N) stage. Conclusion: In this study, we established the role of negative ERCC1 expression in predicting the response to chemotherapy in neoadjuvant TNBC. Therefore, ERCC1 can be used as a predictive marker to stratify patients who will benefit from neoadjuvant therapy. Moreover, we also noted an association between ERCC1 expression and nodal metastasis; however, more large-scale studies are needed to establish its role as a prognostic biomarker in TNBC.

Benefit of adjuvant chemotherapy for T1cN0M0 and selected T1bN0M0 triple-negative breast cancer: a nationwide cancer registry-based study

BACKGROUND

The efficacy of adjuvant chemotherapy for T1N0M0 triple-negative breast cancer (TNBC) has not been clearly elucidated. Thus, we aimed to evaluate the efficacy of adjuvant chemotherapy for patients with T1a-cN0M0 TNBC.

PATIENTS AND METHODS

Patients newly diagnosed with TNBC between 2011 and 2015 were identified and followed up until the end of 2020 using the Taiwan Cancer Registry. Univariate and multivariate Cox proportional hazards regression analyses were performed to compare the recurrence-free survival (RFS) and OS between patients who received and those who did not receive adjuvant chemotherapy.

RESULTS

Of the 62 483 patients registered during 2011-2015, 1074 patients with T1N0M0 TNBC (T1a, n = 103; T1b, n = 167; and T1c, n = 804) who underwent definitive breast surgery were included. Overall, 850 (79%) patients received adjuvant chemotherapy; these comprised 24.3%, 67.7%, and 88.6% of the patients with T1a, T1b, and T1c disease, respectively. Over a median follow-up of 7.18 years, a significant RFS and OS benefit from adjuvant chemotherapy was observed in the T1c subgroup but not in the T1a and T1b subgroups. However, subgroup analysis of T1b disease indicated that adjuvant chemotherapy yielded an OS benefit to patients with histological grade III disease (adjusted hazard ratio = 0.08, 95% CI, 0.01-0.77; P = .03).

CONCLUSIONS

Adjuvant chemotherapy improved the RFS and OS in patients with T1cN0M0 TNBC and improved the OS in patients with histological grade III T1bN0M0 disease. Our study advocates for the utilization of adjuvant chemotherapy in patients diagnosed with T1cN0M0 and histological grade III T1bN0M0 TNBC.

Use of chemotherapy and loco-regional therapy in stage IA triple-negative breast cancer and their association with oncologic outcomes: A cancer registry study

We aimed to evaluate the role of adjuvant chemotherapy and loco-regional therapy for stage IA (pT1, pN0) triple-negative breast cancer (TNBC) in a real-world setting. We identified patients with pT1, pN0 TNBC diagnosed between 2009 and 2021 within the Baden-Württemberg cancer registry (BWCR), Germany. Overall survival (OS) was assessed using Kaplan-Meier statistics and multivariate Cox regression models (adjusted for age, use of chemotherapy, local therapy (breast conserving therapy [breast conserving surgery + radiotherapy] vs. mastectomy), and tumor histologic subtype). A total of 1231 patients with a median follow-up of 45.9 months were identified: 1.0% (12 of 1231) with pT1mi stage, 9.5% (117 of 1231) with pT1a, 23.7% (292 of 1231) with pT1b, and 65.8% (810 of 1231) with pT1c. Multivariate Cox regression analysis revealed no significant influence for the use of chemotherapy on OS in pT1b patients (HR 0.90, 95% CI 0.43-1.90). For pT1c patients with Grade 1-2 tumors, the use of chemotherapy was not significantly associated OS (HR 1.01, 95% CI 0.48-2.11) but breast conserving therapy was associated with improved OS (HR 0.41, 95% CI 0.18-0.93). For pT1c patients with Grade 3 tumors, the use of chemotherapy (HR 0.51, 95% CI 0.33-0.78) as well as breast conserving therapy (HR 0.42, 95% CI 0.23-0.76) was associated with OS. This data suggests that OS in stage IA TNBC is strongly influenced by local therapy rather than the use of chemotherapy, except for pT1c patients with Grade 3 tumors. Larger studies with longer-term follow-up are welcomed to fully inform this discussion.

Clinical characteristics, prognosis, and prognostic factors of patients with second primary triple-negative breast cancer: a study based on Surveillance, Epidemiology, and End Results database

This study examined the characteristics of tumors, treatments, and survival outcomes, with a particular focus on the survival-related factors of second primary triple-negative breast cancer (TNBC) in comparison to first primary TNBC. The Surveillance, Epidemiology, and End Results database was utilized to identify and enroll patients diagnosed with TNBC between the years 2010 and 2015. The outcomes of this study were 3-year and 5-year breast cancer-specific survival (BCSS). The multivariate competing risk model was conducted to explore the association between the second primary cancer and BCSS and to estimate risk factors for BCSS of both first and second primary TNBC. The hazard ratio and 95% confidence interval (CI) were evaluation indices. Our study demonstrated that age, histological grade III/IV, high T stage, high N stage, and TNBC were associated with a decreased 3-year and 5-year BCSS in both first and second primary TNBC. Family income ≥$60 000 per year (hazard ratio: 0.68, 95% CI: 0.48-0.95, P = 0.026) correlated with better 3-year BCSS in patients with second primary TNBC. Breast-conserving surgery, mastectomy, and the interval between two cancer diagnoses >3 years were associated with increased 3-year and 5-year BCSS in patients with second primary TNBC (all P < 0.05). This paper reveals a worse survival of second primary TNBC. Great attention should be paid to the prognosis of patients with second primary TNBC.

Tumor-Infiltrating Lymphocytes in Patients With Stage I Triple-Negative Breast Cancer Untreated With Chemotherapy

Importance

The absolute benefit of chemotherapy for all patients with stage I triple-negative breast cancer (TNBC) is unclear, and biomarkers are not currently available for selecting patients with an excellent outcome for whom neoadjuvant or adjuvant chemotherapy may have negligible benefit. High levels of stromal tumor-infiltrating lymphocytes (sTILs) are associated with favorable survival in TNBC, but data solely in stage I TNBC are lacking.

Objective

To examine the outcomes of patients of all ages with stage I TNBC solely and who received neither neoadjuvant nor adjuvant chemotherapy, according to centrally reviewed sTIL levels at prespecified cutoffs.

Design, Setting, and Participants

This cohort study used the Netherlands Cancer Registry to identify patients diagnosed with stage I TNBC between January 1, 2005, and December 31, 2015, who were not treated with chemotherapy. Only patients who did not receive neoadjuvant and/or adjuvant chemotherapy were selected. The clinical data were matched with their corresponding pathology data provided by the Dutch Pathology Registry. Data analysis was performed between February and October 2023.

Main Outcomes and Measures

The primary end point was breast cancer-specific survival (BCSS) at 5, 10, and 15 years for the prespecified sTIL level cutoffs of 30%, 50%, and 75%. Hematoxylin and eosin-stained slides were used for central review of histologic subtype, grade, and lymphovascular invasion. The International Immuno-Oncology Biomarker Working Group guidelines were used to score the sTIL levels; these levels were determined for 1041 patients.

Results

Of a total of 4511 females with stage I TNBC, patients who were not treated with chemotherapy were selected and tissue blocks requested; sTILs were scored in 1041 patients (mean [SD] age at diagnosis, 64.4 [11.1] years, median follow-up 11.4 [95% CI, 10.9-11.9] years) who were included in the analyses.. Most tumors (952 [91.5%]) were invasive carcinomas of nonspecial histologic subtype. Most patients (548 [52.6%]) had pT1cN0 tumors. Median (range) sTIL level was 5% (1%-99%). A total of 775 patients (74.4%) had sTIL levels below 30%, 266 (25.6%) had 30% or greater, 203 (19.5%) had 50% or greater, and 141 (13.5%) had 75% or greater. Patients with pT1abN0 tumors had a more favorable outcome vs patients with pT1cN0 tumors, with a 10-year BCSS of 92% (95% CI, 89%-94%) vs 86% (95% CI, 82%-89%). In the overall cohort, sTIL levels of at least 30% were associated with better BCSS compared with sTIL levels less than 30% (96% and 87%, respectively; hazard ratio [HR], 0.45; 95% CI, 0.26-0.77). High sTIL levels of 50% or greater were associated with a better outcome than low sTIL levels of less than 50% (HR, 0.27; 95% CI, 0.10-0.74) in patients with pT1C tumors, with a 10-year BCSS of 95% increasing to 98% with sTIL levels of 75% or greater.

Conclusions and Relevance

Results of this study showed that patients with stage I TNBC and high level of sTILs who did not receive neoadjuvant or adjuvant chemotherapy had excellent 10-year BCSS. The findings further support the role of sTILs as integral biomarkers in prospective clinical trials of therapy optimization for this patient population.

CircTRIM1 encodes TRIM1-269aa to promote chemoresistance and metastasis of TNBC via enhancing CaM-dependent MARCKS translocation and PI3K/AKT/mTOR activation

Peptides and proteins encoded by noncanonical open reading frames (ORFs) of circRNAs have recently been recognized to play important roles in disease progression, but the biological functions and mechanisms of these peptides and proteins are largely unknown. Here, we identified a potential coding circular RNA, circTRIM1, that was upregulated in doxorubicin-resistant TNBC cells by intersecting transcriptome and translatome RNA-seq data, and its expression was correlated with clinicopathological characteristics and poor prognosis in patients with TNBC. CircTRIM1 possesses a functional IRES element along with an 810 nt ORF that can be translated into a novel endogenously expressed protein termed TRIM1-269aa. Functionally, we demonstrated that TRIM1-269aa, which is involved in the biological functions of circTRIM1, promoted chemoresistance and metastasis in TNBC cells both in vitro and in vivo. In addition, we found that TRIM1-269aa can be packaged into exosomes and transmitted between TNBC cells. Mechanistically, TRIM1-269aa enhanced the interaction between MARCKS and calmodulin, thus promoting the calmodulin-dependent translocation of MARCKS, which further initiated the activation of the PI3K/AKT/mTOR pathway. Overall, circTRIM1, which encodes TRIM1-269aa, promoted TNBC chemoresistance and metastasis by enhancing MARCKS translocation and PI3K/AKT/mTOR activation. Our investigation has yielded novel insights into the roles of protein-coding circRNAs and supported circTRIM1/TRIM1-269aa as a novel promising prognostic and therapeutic target for patients with TNBC.

Prognostic value of histopathologic traits independent of stromal tumor-infiltrating lymphocyte levels in chemotherapy-naïve patients with triple-negative breast cancer

BACKGROUND

In the absence of prognostic biomarkers, most patients with early-stage triple-negative breast cancer (eTNBC) are treated with combination chemotherapy. The identification of biomarkers to select patients for whom treatment de-escalation or escalation could be considered remains an unmet need. We evaluated the prognostic value of histopathologic traits in a unique cohort of young, (neo)adjuvant chemotherapy-naïve patients with early-stage (stage I or II), node-negative TNBC and long-term follow-up, in relation to stromal tumor-infiltrating lymphocytes (sTILs) for which the prognostic value was recently reported.

MATERIALS AND METHODS

We studied all 485 patients with node-negative eTNBC from the population-based PARADIGM cohort which selected women aged <40 years diagnosed between 1989 and 2000. None of the patients had received (neo)adjuvant chemotherapy according to standard practice at the time. Associations between histopathologic traits and breast cancer-specific survival (BCSS) were analyzed with Cox proportional hazard models.

RESULTS

With a median follow-up of 20.0 years, an independent prognostic value for BCSS was observed for lymphovascular invasion (LVI) [adjusted (adj.) hazard ratio (HR) 2.35, 95% confidence interval (CI) 1.49-3.69], fibrotic focus (adj. HR 1.61, 95% CI 1.09-2.37) and sTILs (per 10% increment adj. HR 0.75, 95% CI 0.69-0.82). In the sTILs <30% subgroup, the presence of LVI resulted in a higher cumulative incidence of breast cancer death (at 20 years, 58%; 95% CI 41% to 72%) compared with when LVI was absent (at 20 years, 32%; 95% CI 26% to 39%). In the ≥75% sTILs subgroup, the presence of LVI might be associated with poor survival (HR 11.45, 95% CI 0.71-182.36, two deaths). We confirm the lack of prognostic value of androgen receptor expression and human epidermal growth factor receptor 2 -low status.

CONCLUSIONS

sTILs, LVI and fibrotic focus provide independent prognostic information in young women with node-negative eTNBC. Our results are of importance for the selection of patients for de-escalation and escalation trials.

Benefit of adjuvant chemotherapy in lymph node-negative, T1b and T1c triple-negative breast cancer

INTRODUCTION

Current guidelines recommendations regarding chemotherapy in small (T1b and T1c), node-negative triple-negative breast cancer (TNBC) differ due to lack of high-quality data. Our study aimed to assess the benefit of adjuvant chemotherapy in patients with T1bN0M0 and T1cN0M0 TNBC.

METHODS

We obtained data from the Surveillance, Epidemiology, and End Results database for patients with node-negative, T1b/T1c TNBC diagnosed between 2010 and 2020. Logistic regresion models assessed variables associated with chemotherapy administration. We evaluated the effect of chemotherapy on overall survival (OS) and breast cancer specific survival (BCSS) with Kaplan-Meier methods and Cox proportional hazards methods.

RESULTS

We included 11,510 patients: 3,388 with T1b and 8,122 with T1c TNBC. During a median follow-up of 66 months, 305 patients with T1b and 995 with T1c died. After adjusting for clinicopathological, demographic and treatment factors, adjuvant chemotherapy improved OS in T1b TNBC (HR, 0.52; 95% CI, 0.41-0.68 p < 0.001) but did not improve BCSS (HR, 0.70; 95% CI, 0.45-1.07; p = 0.10); the association between chemotherapy and BCSS was not statistically significant in any subgroup. In T1c TNBC, adjuvant chemotherapy improved OS (HR, 0.54; 95% CI, 0.47-0.62; p < 0.001) and BCSS (HR, 0.79; 95% CI, 0.63-0.99; p = 0.043); the benefit of chemotherapy in OS varied by age (Pinteraction=0.024); moreover, the benefit in BCSS was similar in all subgroups.

CONCLUSIONS

Our study results support the use of adjuvant chemotherapy in patients with node-negative, T1c TNBC. Patients with node-negative, T1b TNBC had excellent long-term outcomes; furthermore, chemotherapy was not associated with improved BCSS in these patients.

Assessment of Use and Impact of Chemotherapy in Lymph Node-Negative, T1a Triple-Negative Breast Cancer

BACKGROUND

Current treatment guidelines suggest considering adjuvant chemotherapy in high-risk patients with T1a, node-negative triple-negative breast cancer (TNBC); however, limited quality data support this statement. Our population-based study assessed the efficacy of adjuvant chemotherapy and factors associated with its administration in node-negative, T1a TNBC.

MATERIALS AND METHODS

We obtained data from the Surveillance, Epidemiology, and End Results database for patients with T1aN0 TNBC diagnosed between 2010 and 2019. We utilized the Kaplan-Meier method and Cox regression model to analyze the overall survival (OS) and breast cancer-specific survival (BCSS) in chemotherapy benefit. We performed stratified models to identify differences in OS and BCSS between those who received chemotherapy and those who did not across subgroups. Competing risk analysis was conducted to assess differences in risk of breast cancer death in patients with chemotherapy administration versus no chemotherapy. Additionally, propensity score matching was executed to assess survival analysis in a matched cohort.

RESULTS

We included 1739 patients with T1a TNBC. Patients who received chemotherapy were younger, had higher histological grade and ductal histology subtype, were more likely to be married and undergo mastectomy. Our study did not show improvement in OS (HR, 0.63; 95% CI, 0.35-1.13; P = .122) or BCSS (HR, 0.95; 95% CI, 0.37-2.43; P = .908) after chemotherapy use. We did not identify any subgroup of patients that may benefit from chemotherapy. Without chemotherapy, 8-year risk of breast cancer death is 2.75% for these patients.

CONCLUSION

Adjuvant chemotherapy is not associated with benefit on OS or BCSS in node-negative, T1a TNBC.

Treatment optimization in early triple negative breast cancer

INTRODUCTION

The treatment of early-stage triple-negative breast cancer (TNBC) has radically changed in recent years. Response to neoadjuvant treatment has provided prognostic information, and the achievement of a pathological complete response (pCR) is associated with improved prognosis. An exact treatment algorithm that embraces the trade-off of efficacy and toxicity in a risk-adapted manner has, however, not been consolidated.

AREAS COVERED

In this review, we focused on the current treatments used for patients with early triple negative breast cancer, aiming at framing a therapeutic approach toward risk-adapted treatment optimization. We reviewed the clinical trials and other evidence at the foundation of the current clinical practice in early TNBC and identified possible areas of clinical implementation.

EXPERT OPINION

In our opinion, treatment optimization will ensure improved patient-centric outcomes, with less toxicities, better long-term quality of life and risk-adapted treatment modulation. Presently, treatment modulation can be applied in some patients through de-intensification, for small TNBC, informed by novel biomarkers and based on the response to neoadjuvant treatments, especially in the case of pCR. Innovative approaches should incorporate baseline risk and cancer biology, treatment response, and post-surgery biomarkers of prognosis, to deliver risk-adapted treatments for patients with early TNBC.

Adjuvant chemotherapy in patients with ER-negative/HER2-negative, T1abN0 breast cancer: a nationwide study

PURPOSE

The purpose of this study was to examine the effect of chemotherapy on invasive disease-free survival (iDFS) and overall survival (OS) in a nationwide cohort of patients with estrogen receptor (ER)-negative/human epidermal growth factor receptor 2 (HER2)-negative, T1abN0 breast cancer.

METHODS

Patients with ER-negative/HER2-negative, T1abN0 breast cancer registered in the Danish Breast Cancer Group database between 2007 and 2016 were identified. The effect of adjuvant chemotherapy on iDFS and OS was analyzed with Cox proportional hazards analysis.

RESULTS

In total, 296 patients were included in the statistical analyses. Of these, 235 (79.4%) received chemotherapy and 61 patients (20.6%) did not. Patients treated with chemotherapy were significantly younger, had a significantly higher proportion of grade 3 tumors, T1b tumors, and tumors of ductal subtype. With 7.7 years of median follow-up, treatment with chemotherapy was associated with a significant improvement in OS in the adjusted analysis, Hazard Ratio 0.35 (95% Confidence Interval (0.15-0.81), p = 0.02), chemotherapy vs. no chemotherapy. In the unadjusted analyses, patients with both T1a and T1b tumors had significantly improved OS with chemotherapy. At 5 years, OS was 100% vs. 94.4% and 93.8% vs. 81.3% for patients with T1a and T1b tumors, respectively, chemotherapy vs. no chemotherapy. With 4.9 years of median follow-up, iDFS was not significantly improved with chemotherapy.

CONCLUSION

Patients with ER-negative/HER2-negative, T1abN0 breast cancer had significantly improved OS when treated with chemotherapy. This improvement was significant in patients with both T1a and T1b tumors, respectively. The effect was, however, limited in patients with T1a tumors.

Are we overtreating stage I triple-negative breast cancer in Ontario? A population-based retrospective epidemiological analysis using the ICES database

Triple-negative breast cancer (TNBC) is associated with inferior outcomes. The use of adjuvant chemotherapy is the mainstay of treatment, and its efficacy was demonstrated to be correlated with tumor size. Different guidelines exist regarding chemotherapy in early-stage TNBC. This study uses ICES database to examine the outcomes of the use of adjuvant chemotherapy in stage I TNBC in Ontario stratified by tumor size. Records of TNBC patients diagnosed in 2012 to 2014 were collected from ICES database. Stage I patients were analyzed by tumor size: T1a (≤ 0.5 cm), T1b (> 0.5 cm and ≤ 1.0 cm), and T1c (> 1.0 cm and ≤ 2.0 cm). Kaplan-Meier curves, log-rank test statistic, and Cox's proportional hazard regression were used to compare differences in overall survival (OS) between chemotherapy and no-chemotherapy groups. Of 610 patients, 183 had tumor sizes ≤ 1 cm, representing stages T1aN0M0 and T1bN0M0, and 427 had tumors > 1 cm to 2 cm, representing stage T1cN0M0. Patients with tumors ≤ 1 cm who received chemotherapy did not have a significant difference in OS compared to the no-chemotherapy group (p = 0.41, hazard ratio (HR) 0.40, 95% confidence interval (CI) 0.021-2.5). However, patients with tumor sizes > 1 cm to 2 cm who received chemotherapy demonstrated significantly better OS compared to those without (p = 0.023, HR = 0.40, 95% CI 0.16-0.86). Patients with TNBC stage T1cN0M0 should receive adjuvant chemotherapy. For TNBC tumors ≤ 1 cm, avoidance of chemotherapy can be considered. Prospective research should further investigate the efficacy of chemotherapy in TNBC stages T1a-bN0M0.Trial Registration University of Windsor REB#16-119.

CircRNA-CREIT inhibits stress granule assembly and overcomes doxorubicin resistance in TNBC by destabilizing PKR

BACKGROUND

Circular RNAs (circRNAs) represent a novel type of regulatory RNA characterized by high evolutionary conservation and stability. CircRNAs are expected to be potential diagnostic biomarkers and therapeutic targets for a variety of malignancies. However, the regulatory functions and underlying mechanisms of circRNAs in triple-negative breast cancer (TNBC) are largely unknown.

METHODS

By using RNA high-throughput sequencing technology, qRT-PCR and in situ hybridization assays, we screened dysregulated circRNAs in breast cancer and TNBC tissues. Then in vitro assays, animal models and patient-derived organoids (PDOs) were utilized to explore the roles of the candidate circRNA in TNBC. To investigate the underlying mechanisms, RNA pull-down, RNA immunoprecipitation (RIP), co immunoprecipitation (co-IP) and Western blotting assays were carried out.

RESULTS

In this study, we demonstrated that circRNA-CREIT was aberrantly downregulated in doxorubicin resistant triple-negative breast cancer (TNBC) cells and associated with a poor prognosis. The RNA binding protein DHX9 was responsible for the reduction in circRNA-CREIT by interacting with the flanking inverted repeat Alu (IRAlu) sequences and inhibiting back-splicing. By utilizing in vitro assays, animal models and patient-derived organoids, we revealed that circRNA-CREIT overexpression significantly enhanced the doxorubicin sensitivity of TNBC cells. Mechanistically, circRNA-CREIT acted as a scaffold to facilitate the interaction between PKR and the E3 ligase HACE1 and promoted proteasomal degradation of PKR protein via K48-linked polyubiquitylation. A reduced PKR/eIF2α signaling axis was identified as a critical downstream effector of circRNA-CREIT, which attenuated the assembly of stress granules (SGs) to activate the RACK1/MTK1 apoptosis signaling pathway. Further investigations revealed that a combination of the SG inhibitor ISRIB and doxorubicin synergistically inhibited TNBC tumor growth. Besides, circRNA-CREIT could be packaged into exosomes and disseminate doxorubicin sensitivity among TNBC cells.

CONCLUSIONS

Our study demonstrated that targeting circRNA-CREIT and SGs could serve as promising therapeutic strategies against TNBC chemoresistance.

Impact of adjuvant chemotherapy on T1N0M0 breast cancer patients: a propensity score matching study based on SEER database and external cohort

BACKGROUND

There is no clear consensus on the benefits of adjuvant chemotherapy for tumor-node-metastasis (TNM) stage T1 (T1N0M0) breast cancer (BC). Our study investigated the effects of adjuvant chemotherapy on T1N0M0 BC patients.

METHODS

Seventy-five thousand one hundred thirty-nine patients diagnosed with T1N0M0 BC were selected from the Surveillance, Epidemiology, and End Results (SEER) database. Multivariate Cox analyses were performed to investigate the effects of adjuvant chemotherapy on T1a, T1b, and T1cN0M0 BC, including various tumor grades, and four molecular subtypes. Propensity score matching (PSM) was used to eliminate confounding factors and further compare the results between adjuvant chemotherapy and no adjuvant chemotherapy. Additionally, 545 T1N0M0 BC patients treated at the Northern Jiangsu People's Hospital were included as an independent external validation cohort. Univariate and multivariate Cox analyses were used to confirm the effects of adjuvant chemotherapy in T1a, T1b, and T1cN0M0 BC. Survival curves for the different tumor grades and molecular subtypes were plotted using the Kaplan-Meier method.

RESULTS

Adjuvant chemotherapy demonstrated a statistically significant improvement in overall survival (OS) in T1b and T1c BC, but not in T1a BC. Within T1b BC, adjuvant chemotherapy was found to have effects on grade III, and hormone receptor + (HoR +)/human epidermal growth factor receptor 2 + (HER2 +), HoR-/HER2 + , and HoR-/HER2- molecular subtypes, respectively. Adjuvant chemotherapy was beneficial to OS for grade II/III and T1c BC. Identical results were obtained after PSM. We also obtained similar results with external validation cohort, except that adjuvant chemotherapy made a difference in grade II and T1b BC of the external validation dataset.

CONCLUSIONS

Partial T1N0M0 BC patients with grade III T1bN0M0, patients with tumor grade II and III T1cN0M0, and excluding those with HoR + /HER2- subtype tumors, could obtain OS benefits from adjuvant chemotherapy.

Survival outcome assessment for triple-negative breast cancer: a nomogram analysis based on integrated clinicopathological, sonographic, and mammographic characteristics

Objective

This study aimed to incorporate clinicopathological, sonographic, and mammographic characteristics to construct and validate a nomogram model for predicting disease-free survival (DFS) in patients with triple-negative breast cancer (TNBC).

Methods

Patients diagnosed with TNBC at our institution between 2011 and 2015 were retrospectively evaluated. A nomogram model was generated based on clinicopathological, sonographic, and mammographic variables that were associated with 1-, 3-, and 5-year DFS determined by multivariate logistic regression analysis in the training set. The nomogram model was validated according to the concordance index (C-index) and calibration curves in the validation set.

Results

A total of 636 TNBC patients were enrolled and divided into training cohort (n = 446) and validation cohort (n = 190). Clinical factors including tumor size > 2 cm, axillary dissection, presence of LVI, and sonographic features such as angular/spiculated margins, posterior acoustic shadows, and presence of suspicious lymph nodes on preoperative US showed a tendency towards worse DFS. The multivariate analysis showed that no adjuvant chemotherapy (HR = 6.7, 95% CI: 2.6, 17.5, p < 0.0005), higher axillary tumor burden (HR = 2.7, 95% CI: 1.0, 7.1, p = 0.045), and ≥ 3 malignant features on ultrasound (HR = 2.4, CI: 1.1, 5.0, p = 0.021) were identified as independent prognostic factors associated with poorer DFS outcomes. In the nomogram, the C-index was 0.693 for the training cohort and 0.694 for the validation cohort. The calibration plots also exhibited excellent consistency between the nomogram-predicted and actual survival probabilities in both the training and validation cohorts.

Conclusions

Clinical variables and sonographic features were correlated with the prognosis of TNBCs. The nomogram model based on three variables including no adjuvant chemotherapy, higher axillary tumor load, and more malignant sonographic features showed good predictive performance for poor survival outcomes of TNBC.

Key Points

• The absence of adjuvant chemotherapy, heavy axillary tumor load, and malignant-like sonographic features can predict DFS in patients with TNBC.

• Mammographic features of TNBC could not predict the survival outcomes of patients with TNBC.

• The nomogram integrating clinicopathological and sonographic characteristics is a reliable predictive model for the prognostic outcome of TNBC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-022-08910-4.

Systemic Therapy De-Escalation in Early-Stage Triple-Negative Breast Cancer: Dawn of a New Era?

Simple Summary

Triple-negative breast cancer is a life-threatening disease, even when identified at early stages. Recent advances have allowed the improvement of life expectancy via a personalized approach with the addition of newer chemotherapies, immunotherapies, and targeted therapies, but at the cost of added side effects. It has become increasingly clear that not all patients need such aggressive treatment. Here, we provide an overview of emerging opportunities to use less toxic therapies in patients at lower risk of recurrence or with mutations that can be effectively targeted using novel approaches. We provide a comprehensive review of completed and ongoing clinical trials with information on how to best stratify these patients for treatments to obtain maximum benefit without unnecessary toxicities.

Abstract

Early-stage triple negative breast cancer (TNBC) has been traditionally treated with surgery, radiation, and chemotherapy. The current standard of care systemic treatment of early-stage II and III TNBC involves the use of anthracycline-cyclophosphamide and carboplatin-paclitaxel with pembrolizumab in the neoadjuvant setting followed by adjuvant pembrolizumab per KEYNOTE-522. It is increasingly clear that not all patients with early-stage TNBC need this intensive treatment, thus paving the way for exploring opportunities for regimen de-escalation in selected subgroups. For T1a tumors (≤5 mm), chemotherapy is not used, and for tumors 6–10 mm (T1b) in size with negative lymph nodes, retrospective studies have failed to show a significant benefit with chemotherapy. In low-risk patients, anthracycline-free chemotherapy may be as effective as conventional therapy, as shown in some studies where replacing anthracyclines with carboplatin has shown non-inferior results for pathological complete response (pCR), which may form the backbone of future combination therapies. Recent advances in our understanding of TNBC heterogeneity, mutations, and surrogate markers of response such as pCR have enabled the development of multiple treatment options in the (neo)adjuvant setting in order to de-escalate treatment. These de-escalation studies based on tumor mutational status, such as using Poly ADP-ribose polymerase inhibitors (PARPi) in patients with BRCA mutations, and new immunotherapies such as PD1 blockade, have shown a promising impact on pCR. In addition, the investigational use of (bio)markers, such as high levels of tumor-infiltrating lymphocytes (TILs), low levels of tumor-associated macrophages (TAMs), and complete remission on imaging, also look promising. In this review, we cover the current standard of care systemic treatment of early TNBC and review the opportunities for treatment de-escalation based on clinical risk factors, biomarkers, mutational status, and molecular subtype.

Low-risk triple-negative breast cancers: Clinico-pathological and molecular features

Triple-negative breast cancers (TNBC) comprise biologically and clinically heterogeneous diseases characterized by the lack of hormone receptors (HR) and HER2 expression. This subset of tumors accounts for 15-20% of all breast cancers and pursues an ominous clinical course. However, there is a spectrum of low-risk TNBCs with no/minimal metastatic potential, including the salivary gland-type tumors, those with extensive apocrine differentiation and/or high tumor-infiltrating lymphocytes, and small-sized, early-stage (pT1a/bN0M0) TNBCs. De-escalating the treatment in low-risk TNBC, however, is not trivial because of the substantial lack of dedicated randomized clinical trials and cancer registries. The development of new diagnostic and/or prognostic biomarkers based on clinical and molecular aspects of low-risk TNBCs would lead to improved clinical treatment. Here, we sought to provide a portrait of the clinicopathological and molecular features of low-risk TNBC, with a focus on the diagnostic challenges along with the most important biological characteristics underpinning their favorable clinical course.

Benefit of adjuvant chemotherapy in node-negative T1a versus T1b and T1c triple-negative breast cancer

PURPOSE

National comprehensive cancer network guidelines recommend delivery of adjuvant chemotherapy in node-negative triple-negative breast cancer (TNBC) if the tumor is > 1 cm and consideration of adjuvant chemotherapy for T1b but not T1a disease. These recommendations are based upon sparse data on the role of adjuvant chemotherapy in T1a and T1b node-negative TNBC. Our objective was to clarify the benefits of chemotherapy for patients with T1N0 TNBC, stratified by tumor size.

METHODS

We performed a retrospective analysis of survival outcomes of TNBC patients at two academic institutions in the United States from 1999 to 2018. Primary tumor size, histology, and nodal status were based upon surgical pathology. The Kaplan-Meier plot and 5-year unadjusted survival probability were evaluated.

RESULTS

Among 282 T1N0 TNBC cases, the status of adjuvant chemotherapy was known for 258. Mean follow-up was 5.3 years. Adjuvant chemotherapy was delivered to 30.5% of T1a, 64.7% T1b, and 83.9% T1c (p < 0.0001). On multivariable analysis, factors associated with delivery of adjuvant chemotherapy were tumor size and grade 3 disease. Improved overall survival was associated with use of chemotherapy in patients with T1c disease (93.2% vs. 75.2% p = 0.008) but not T1a (100% vs. 100% p = 0.3778) or T1b (100% vs. 95.8% p = 0.2362) disease.

CONCLUSION

Our data support current guidelines indicating benefit from adjuvant chemotherapy in node-negative TNBC associated with T1c tumors but excellent outcomes were observed in the cases of T1a and T1b disease, regardless of whether adjuvant chemotherapy was delivered.

Prognostic Factors and Models for Elderly (≥70 Years Old) Primary Operable Triple-Negative Breast Cancer: Analysis From the National Cancer Database

BACKGROUND

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer. In the elderly (≥70 years old) primary operable (T_1-3N_0-1M₀) TNBC, individualized treatment modalities for this population are pivotal and important, but limited studies are explored.

METHODS

The clinicopathological features of elderly primary operable TNBC patients were retrospectively selected from the Surveillance, Epidemiology, and End Results (SEER) database between January 2010 and December 2015. Kaplan-Meier curves were used to show the survival patterns in the different subgroups. Multivariate Cox analysis was used to identify independent risk factors in the 3-, 5-, and 7- year overall survival (OS) and cancer-specific survival (CSS) in this subpopulation. The predictive model was further developed and validated for clinical use.

RESULT

Between 2010 and 2015 years, a total of 4,761 elderly primary operable TNBC patients were enrolled for the study, with a mean age of 76 years and a median follow-up of 56 months. The multivariate Cox analysis showed that age (increased per year: hazard ratio (HR) = 1.05), race (Asian/Pacific Islander and American Indian/Alaska Native, HR = 0.73), differentiation grade (grade II: HR = 2.01; grade III/IV: HR = 2.67), larger tumor size (T_1c: HR = 1.83; T₂: HR = 2.78; T₃: HR = 4.93), positive N stage (N_1mi: HR = 1.60; N₁: HR = 1.54), receiving radiation therapy (HR = 0.66), and receiving adjuvant chemotherapy (HR = 0.61) were the independent prognostic factors for OS, and a similar prognostic pattern was also determined in CSS. Besides, two nomograms for predicting the 3-, 5-, and 7-year OS and CSS in this population were developed with a favorable concordance index of 0.716 and 0.746, respectively.

CONCLUSION

The results highlight that both radiation and adjuvant chemotherapy are significantly associated with favorable long-term OS and CSS probability in elderly primary operable TNBC patients. Based on the determined independent prognostic factors, the novel nomograms could assist the oncologists to make individualized clinical decisions for the subpopulation at different risks.

Triple-negative breast cancer outcomes: Does AJCC 8th staging improve chemotherapy decision-making

PURPOSE

To investigate the effect of the 8th American Joint Committee on Cancer (AJCC) pathological prognostic staging on chemotherapy decision-making for triple-negative breast cancer (TNBC) patients with T1-2N0M0 disease.

METHODS

Patients diagnosed with T1-2N0M0 TNBC were retrieved from the Surveillance, Epidemiology, and End Results program. Statistical methods including Kaplan-Meier survival curve, receiver operating characteristics curve, and Cox proportional hazard model.

RESULTS

We identified 12,156 patients, including 9371 (77.1%) patients who received chemotherapy. Overall, 57.4% of patients (n = 6975) were upstaged after being reassigned by the 8th AJCC staging. However, the 8th staging of AJCC did not have a greater prognostic value compared to the 7th staging (P = 0.064). The receipt of chemotherapy significantly improved the breast cancer-specific survival for stage T1c and T2 tumors (P < 0.001), but not for stage T1a (P = 0.188) and T1b (P = 0.376) tumors. Using AJCC 8th staging, chemotherapy benefit was only found in stage IIA patients (P = 0.002), but not for stage IA (P = 0.653) and IB (P = 0.492) patients. There were 9564 patients with stage T1c and T2 diseases and 4979 patients with 8th AJCC stage IIA disease. Therefore, approximately half of patients (47.9%, n = 4585) may be safe to omit chemotherapy using the AJCC 8th staging compared to the current chemotherapy recommendation for T1-2N0M0 TNBC.

CONCLUSION

The 8th AJCC staging system did not demonstrate the superior discriminatory ability of prognostic stratification than the 7th AJCC staging system in T1-2N0M0 TNBC. However, this new AJCC staging could more accurately predict the chemotherapy benefit, thereby enabling more patients to avoid unnecessary chemotherapy.

Immune Cell Infiltration-Based Characterization of Triple-Negative Breast Cancer Predicts Prognosis and Chemotherapy Response Markers

Breast cancer represents the number one cause of cancer-associated mortality globally. The most aggressive molecular subtype is triple negative breast cancer (TNBC), of which limited therapeutic options are available. It is well known that breast cancer prognosis and tumor sensitivity toward immunotherapy are dictated by the tumor microenvironment. Breast cancer gene expression profiles were extracted from the METABRIC dataset and two TNBC clusters displaying unique immune features were identified. Activated immune cells formed a large proportion of cells in the high infiltration cluster, which correlated to a good prognosis. Differentially expressed genes (DEGs) extracted between two heterogeneous subtypes were used to further explore the underlying immune mechanism and to identify prognostic biomarkers. Functional enrichment analysis revealed that the DEGs were predominately related to some processes involved in activation and regulation of innate immune signaling. Using network analysis, we identified two modules in which genes were selected for further prognostic investigation. Validation by independent datasets revealed that CXCL9 and CXCL13 were good prognostic biomarkers for TNBC. We also performed comparisons between the above two genes and immune markers (CYT, APM, TILs, and TIS), as well as cell checkpoint marker expressions, and found a statistically significant correlation between them in both METABRIC and TCGA datasets. The potential of CXCL9 and CXCL13 to predict chemotherapy sensitivity was also evaluated. We found that the CXCL9 and CXCL13 were good predictors for chemotherapy and their expressions were higher in chemotherapy-responsive patients in contrast to those who were not responsive. In brief, immune infiltrate characterization on TNBC revealed heterogeneous subtypes with unique immune features allowed for the identification of informative and reliable characteristics representative of the local immune tumor microenvironment and were potential candidates to guide the management of TNBC patients.

When the World Throws You a Curve Ball: Lessons Learned in Breast Cancer Management

In the care of patients with operable breast cancer, there has been a shift toward increasing use of neoadjuvant therapy. There are benefits to neoadjuvant therapy, such as monitoring for response, as well as an increased rate of breast conservation and reduction of potential morbidity associated with breast surgery, including axillary management. Among patients with highly proliferative tumors, such as HER2-positive or triple-negative breast cancer, those with residual disease are at higher risk of recurrence, which informs the recommended systemic therapy in the adjuvant setting. For instance, in patients with residual disease after neoadjuvant chemotherapy and HER2-targeted therapy, there is a role for adjuvant trastuzumab emtansine for those with residual disease at the time of surgery. The same holds true regarding the role of adjuvant capecitabine in patients with residual disease after neoadjuvant chemotherapy. With the added complexities of treating patients in the era of the COVID-19 outbreak, additional considerations are critical, including initiation of surgery within an appropriate time from completion of neoadjuvant therapy. National consensus guidelines on time to surgery must be developed to improve measurement and comparison across systems. In addition, there is emerging radiation treatment management research addressing a number of factors, including hypofractionation, role of proton beam therapy, safe omission of radiotherapy, and preoperative radiotherapy with or without drug combination. In this article, the multidisciplinary approach of treating patients with operable breast cancer is highlighted, with updates and future considerations described.

Adjuvant and Neoadjuvant Treatment of Triple-Negative Breast Cancer With Chemotherapy

ABSTRACT

Triple-negative breast cancer (TNBC) accounts for 15% to 20% of all invasive breast carcinomas and is defined by the lack of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. Although TNBC is characterized by high rates of disease recurrence and worse survival, it is significantly more sensitive to chemotherapy as compared with other breast cancer subtypes. Accordingly, despite great efforts in the genomic characterization of TNBC, chemotherapy still represents the cornerstone of treatment. For the majority of patients with early-stage TNBC, sequential anthracycline- and taxane-based neoadjuvant chemotherapy (NACT) represents the standard therapeutic approach, with pathological complete response that strongly correlates with long-term survival outcomes. However, some issues about the optimal neoadjuvant regimen, as well as the effective role of chemotherapy in patients with residual disease after NACT, are still debated. Herein, we will review the current evidences that guide the use of (neo)adjuvant chemotherapy in patients with early-stage TNBC. Furthermore, we will discuss current controversies, including the incorporation of platinum compounds to the neoadjuvant backbone and the optimal treatment for patients with residual disease after NACT. Lastly, we will outline potential future directions that can guide treatment escalation and de-escalation, as well as the development of new therapies. In our view, the application of multi-omics technologies, liquid biopsy assays, and machine learning algorithms are strongly warranted to pave the way toward personalized anticancer treatment for early-stage TNBC.