Effect of Pembrolizumab Plus Neoadjuvant Chemotherapy on Pathologic Complete Response in Women With Early-Stage Breast Cancer: An Analysis of the Ongoing Phase 2 Adaptively Randomized I-SPY2 Trial

Predictors of Pathologic Complete Response with Neoadjuvant Chemo-Immunotherapy in Early-Stage Triple-Negative Breast Cancer

BACKGROUND

The combination of pembrolizumab with neoadjuvant chemotherapy (NAC) for triple-negative breast cancer (TNBC) improves pathologic complete response (pCR) rates and event-free survival. Yet it is unclear which patients benefit most from the addition of immunotherapy. This study aims to identify predictive factors for pCR in patients with TNBC receiving chemo-immunotherapy (chemo-IO).

PATIENTS AND METHODS

This single-institution retrospective analysis included 283 consecutive patients with TNBC treated with neoadjuvant chemo-IO from 1 June 2021 to 20 January 2023. The primary outcome was overall pCR; secondary outcomes were breast pCR and nodal pCR. Univariate and multivariable logistic regression models assessed for characteristics associated with overall, breast, or nodal pCR.

RESULTS

Most patients presented with cT2 (71%) cN0 (54%) disease. The overall pCR rate was 57%, breast pCR was 58%, and axillary pCR was 67% among biopsy-proven cN+ patients. Race, pathogenic BRCA mutations, backbone chemotherapy regimen, immune-related adverse events, and disruptions in immunotherapy were not associated with pCR. Univariate associations with overall pCR were younger age (p = 0.04), lower clinical T stage (p = 0.01), ductal histology (p < 0.001), poor differentiation (p < 0.001), and unifocality (p < 0.001). Breast and axillary pCR had similar associations. Nodal pCR also had univariate associations with normal body mass index (BMI) (p = 0.04) and absence of lymphovascular invasion (LVI) (p = 0.04). On multivariable analyses, ductal histology and unifocality remained independently associated with overall and breast pCR.

CONCLUSIONS

This analysis showed few clinical variables to be independently associated with pCR after neoadjuvant chemo-IO for TNBC. Thus, predicting chemo-IO response to personalize treatment and minimize morbidity may instead lie in ongoing basic and translational research to assess for useful biomarkers.

Role of imaging based response assesment for adapting neoadjuvant systemic therapy for breast cancer: A systematic review

PURPOSE

The objective of this systematic review is to investigate the role of imaging in response monitoring during neoadjuvant systemic therapy (NST) for breast cancer and assess whether treatment modifications based on imaging response are implemented in clinical practice.

METHODS

A systematic review was conducted, analyzing five clinical practice guidelines and 147 clinical trial publications involving NST for breast cancer. The snowballing technique was employed, using a "start set" of clinical guidelines to trace relevant trials. Additionally, a PubMed search was conducted to identify trials published between 2023-2024. The review analyzed the use of imaging modalities, timing, and response criteria, and whether escalation, de-escalation, or change of treatment occurred based on imaging response.

RESULTS

Imaging was utilized in 81 % (119/147) of the trials, with ultrasound, MRI, and mammography being the most frequently employed modalities. Mid-treatment imaging was applied in 56 % (83/147) of the trials. However, only 15 % (22/147) of the trials implemented treatment modifications based on imaging response, highlighting the limited application of imaging response-guided therapy. No standardized imaging protocols or consistent response-guided treatment strategies were identified across the trials or clinical practice guidelines, with considerable variability in imaging methods, timing, and response criteria.

CONCLUSION

This systematic review underscores the critical need for standardized imaging protocols, response assessment criteria and image-guided treatment decisions. It is therefore evident that imaging for response monitoring during treatment should preferably be performed within clinical trials.

Immunotherapy in Triple-Negative Breast Cancer

Currently, immunotherapy has led to a paradigmatic shift in the treatment of many cancer types, including triple-negative breast cancer. Immunotherapy increases the efficacy of the immune system in treating cancer, with a durable effect due to immunologic memory. The PD-1 inhibitor, pembrolizumab, combined with neoadjuvant chemotherapy, improved event-free survival and is a new standard of care for patients with high-risk, early stage triple-negative breast cancer (TNBC), regardless of tumor PD-L1 expression. For metastatic TNBC, pembrolizumab combined with chemotherapy is a new standard of care for first-line therapy for PD-L1+ metastatic TNBC, and it improves overall survival. The PD-L1 inhibitor, atezolizumab, combined with nab-paclitaxel, is also approved for first-line treatment of metastatic PD-L1+ TNBC. The aim of this review is to examine the existing evidence and ongoing studies on immunotherapy in patients with early stage and metastatic triple-negative breast cancer (TNBC), including new combination strategies with several drugs, such as chemotherapy, targeted therapy, or radiation and to discuss immune checkpoint inhibitor (ICI) applications and the possibility of emerging strategies in different TNBC stages.

Immunotherapy in breast cancer: current landscape and emerging trends

Breast cancer remains one of the most prevalent malignancies worldwide, underscoring an urgent need for innovative therapeutic strategies. Immunotherapy has emerged as a transformative frontier in this context. In triple-negative breast cancer (TNBC), the combination of immunotherapy based on PD-1/PD-L1 immune checkpoint inhibitors (ICIs) with chemotherapy has proven efficacious in both early and advanced clinical trials. These encouraging results have led to the approval of ICIs for TNBC, opening up new therapeutic avenues for challenging-to-treat patient populations. Furthermore, a multitude of ongoing trials are actively investigating the efficacy of immunotherapy-based combinations, including ICIs in conjunction with chemotherapy, targeted therapy and radiation therapy, as well as other novel strategies such as bispecific antibodies, CAR-T cells and cancer vaccines across all breast cancer subtypes, including HR-positive/HER2-negative and HER2-positive disease. This review provides a comprehensive overview of current immunotherapeutic approaches in breast cancer, highlighting pivotal findings from recent clinical trials and the potential impact of these advancements on patient outcomes.

Immunotherapy in primary hormone-receptor positive breast cancer: A systematic review

Hormone-receptor positive (HR+), HER2 negative breast cancer (BC) is considered immunologically silent, thus investigation of immunotherapy in this subtype has evolved slower. This systematic review offers an overview of the clinical trials investigating the safety and efficacy of ICI in primary HR+/HER2- BC. Literature search was conducted up to October 30, 2022 to identify immunotherapy trials with checkpoint inhibitors in non-metastatic HR+/HER2- breast cancer. 39 trials were identified, mainly in early-phase clinical trials. None of the trials investigate ICI monotherapy and only 2 Phase 3 clinical trials are ongoing. Most trials investigate the use of ICI in the neoadjuvant setting in combination with chemotherapy. 18 trials have reported results and 6 of them efficacy results specifically for HR+/HER2- BC. ICI could be a promising therapeutic strategy for HR+/HER2- BC, however clinical benefit is restricted to subgroups of patients, depending on tumor molecular profile.

Impact of margin distance on recurrence and survival following breast-conserving surgery after neoadjuvant systemic therapy

Current evidence does not support the application of "no-ink-on-tumor" negative margins following breast-conserving surgery (BCS) in breast cancer (BC) patients who have received neoadjuvant systemic treatment (NST). We compared loco-regional free survival (LRFS), disease-free survival (DFS), and overall survival (OS) based on different tumor margin distance thresholds in a cohort of 235 BC patients treated with NST and subsequent BCS between 01/2015 and 12/2019. The 5-year LRFS was 81.6% in patients with "no-ink-on-tumour", margins and 71.0% in those with positive margins (p = 0.584). Margins >1 mm were associated with superior outcomes, with a 5-year LRFS of 84.0% compared to 69.3% in patients with margins ≤1 mm (p = 0.005). Additionally, margins >1 mm were significantly correlated with longer DFS (p = 0.028) and OS (p = 0.001). These findings suggest that a surgical margin distance >1 mm provides the best LRFS, DFS, and OS outcomes for this group of BC patients.

Comparative efficacy and safety of PD-1 versus PD-L1 inhibitors in breast cancer treatment: A systematic review and meta analysis

The comparative efficacy and safety of programmed death-ligand 1 (PD-L1) inhibitors versus programmed death protein 1 (PD-1) inhibitors in breast cancer treatment remain inconclusive, as no head-to-head randomized controlled trials (RCTs) conducted. This study aims to evaluate the efficacy and safety of PD-1/PD-L1 inhibitors as monotherapy or in combination with chemotherapy for breast cancer. A systematic review and meta-analysis were performed using major databases and oncology conference proceedings. The primary outcomes were overall survival (OS) for advanced breast cancer and pathological complete response (PCR) rate for early breast cancer. Secondary outcomes included progression-free survival (PFS) for advanced breast cancer and incidence of adverse events (AEs). Seventeen studies met the inclusion criteria, consisting of seven RCTs on early-stage and 10 on advanced breast cancer. For advanced breast cancer, PD-1/PD-L1 inhibitors modestly improved OS compared to chemotherapy, with no significant differences between PD-1 and PD-L1 inhibitors. PD-L1 inhibitors showed greater improvement in PFS compared to PD-1 inhibitors. The likelihood of AEs of any grade was higher with PD-L1 inhibitor treatment than with PD-1 inhibitor treatment. In early breast cancer, combining PD-1/PD-L1 inhibitors with chemotherapy inducing higher PCR rates than chemotherapy alone, with PD-1 inhibitors achieving better outcomes than PD-L1 inhibitors. PD-1 inhibitors were linked to slightly higher rates of grade >2 AEs compared to PD-L1 inhibitors. The findings indicate that PD-1 inhibitors may offer advantages for advanced breast cancer due to similar OS and a lower rate of AEs. For early breast cancer, PD-1 inhibitors are recommended given their superior PCR rates.

Association between transcriptomic metrics of exogenous antigen presentation and adaptive immunity with locoregional recurrence in localized estrogen receptor negative breast cancer: retrospective review of multi-institutional datasets

BACKGROUND

Transcriptomic features of breast cancer locoregional recurrence (LRR) remain poorly understood. We therefore sought to investigate transcriptomic features associated with LRR in newly diagnosed invasive breast tumors from our institutional dataset.

METHODS

Transcriptomic profiling was performed on 632 tumors from consecutive patients treated within our health system for newly diagnosed non-metastatic breast cancer. Univariable Cox models identified genes whose expression was associated with LRR (q-value < 0.05). Up-regulated (UR) genes were defined as hazard ratio (HR) > 1 and down-regulated (DR) genes were defined as HR < 1. Gene set enrichment analyses were performed for UR and DR gene sets and validated within two external cohorts of ER- tumors.

RESULTS

With a median follow-up of 7.6 years, we observed 38 LRRs: 28/481 (5.8%) in ER + and 10/151 (6.6%) in ER-. There were 43 UR and 7 DR genes associated with LRR in ER + tumors, while 417 UR and 1150 DR genes were associated with LRR in ER- tumors. UR genes in ER + tumors were enriched for roles in cell proliferation (q < 0.05). In contrast, LRR in ER- tumors was most strongly associated with DR genes enriched for MHC-II-mediated antigen presentation and T cell activation (q < 0.05). In external cohorts of ER- tumors, 97 significant DR genes (p < 0.05) were enriched for 18 pathways, including 5 pathways involved in MHC-II signaling, antigen presentation and T-cell activation.

CONCLUSIONS

Transcriptomic patterns associated with LRR appear distinct between ER + and ER- tumors. In ER + tumors, LRR appears predominantly associated with proliferation, whereas ER- LRR suggests a robust pattern of suppressed antigen presentation via MHC-II.

Advancing breast cancer therapy in the era of molecular diagnostics

Advances in cancer biology and drug development now enable treatments tailored to individual tumor profile. Targeting specific molecular alterations marked a significant step forward in cancer care, including breast cancer. Access to these therapies is improving thanks to the implementation of molecular tumor boards and efforts to provide molecular diagnostics at sustainable costs for all. In this context, we highlight recent progress in breast cancer therapy, focusing on biomarker-driven approaches, immunotherapy, and precision medicine paving the way for increasingly personalized and effective options.

Current Status of Immune Checkpoint Inhibitors and Treatment Responsive Biomarkers for Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC), accounting for about 10%-20% of all breast cancer cases, is characterized by its aggressive nature, high recurrence rates, and poor prognosis. Unlike other breast cancer subtypes, TNBC lacks hormone receptors and specific molecular targets, limiting therapeutic options. In recent years, immune checkpoint inhibitors (ICIs) have shown promise in treating TNBC by targeting immune evasion mechanisms. Despite these advancements, several issues remain unresolved, including low response rates in programmed cell death ligand 1 (PD-L1) negative TNBC subtypes and the challenge of predicting which patients will benefit from ICIs. Consequently, there is growing interest in identifying reliable biomarkers beyond PD-L1 expression. This review synthesizes recent studies to provide a comprehensive perspective on ICI therapy in TNBC, clarifying the status of single-agent ICI therapies and combination strategies, emphasizing the need for further research into biomarkers. These insights provide clues for more personalized and effective treatment approaches, ultimately aiming to improve clinical outcomes for patients with TNBC.

Nivolumab and stereotactic radiosurgery for patients with breast cancer brain metastases: long-term results and biomarker analysis from a non-randomized, open-label, phase Ib study

BACKGROUND

We hypothesized treatment with nivolumab and stereotactic radiosurgery (SRS) would be feasible, well tolerated, and may improve intracranial tumor control over SRS alone for breast cancer brain metastases (BCBM).

METHODS

The study is a phase Ib trial of nivolumab and SRS for BCBM.

CLINICAL TRIAL INFORMATION

NCT03807765. Key eligibility criteria include BCBM of all subtypes, age ≥18, Eastern Cooperative Oncology Group Performace Status (ECOG-PS)≤2 with ≤10 brain metastases. Treatment was initiated with a dose of nivolumab (480 mg intravenously) that was repeated every 4 weeks. The initial dose of nivolumab was followed 1 week later by SRS. Blood was collected at baseline and every 4 weeks for flow cytometry and cell-free DNA (cfDNA) assessment.

RESULTS

A total of 12 patients received SRS to 17 brain metastases. Breast cancer subtypes included triple negative (50%), hormone receptor (HR)+/HER2- (33%), and HR-/HER2+ (17%). Median follow-up from start of protocol therapy is 56 months. No cases of radionecrosis were noted. Two lesions were noted to undergo local failure, both pathologically confirmed, for a 12-month local control of 94%. Median distant intracranial control was 7.4 months with a 12-month control rate of 33%. Median systemic progression-free survival was 7.7 months with a 12-month rate of 42%. Median overall survival (OS) was 24.7 months with a 12-month OS of 75%. Most patients were noted to have an increase in cfDNA throughout study treatment, at week 5 compared with baseline (83%), week 25 compared with baseline (89%), and 100% at first follow-up. Intracranial control was associated with lower levels of CD4 regulatory T cells (Treg) (p=0.03) and higher levels of CD4 T effector memory (p=0.04).

CONCLUSIONS

Nivolumab and SRS is a safe and feasible treatment option in BCBM. Long-term follow-up revealed no cases of radiation necrosis.

TRIAL REGISTRATION NUMBER

NCT03807765.

Therapy of early breast cancer: current status and perspectives

Medical advancements in breast cancer are truly remarkable. Especially in recent years, numerous new therapeutics have been approved and surgical strategies have been de-escalated for specific patient groups. In the therapeutic setting, CDK4/6 inhibitors as oral maintenance therapy in early breast cancer and immune checkpoint inhibitors (Pembrolizumab) for triple-negative breast cancer (BC) are noteworthy. In the surgical field, prospective randomized controlled trials have currently explored the possibility to deescalate axillary surgery by omitting sentinel lymph node excision (INSEMA, SOUND). As a result, there have been significant improvements in prognosis and a reduction in surgical morbidity for patients. Many exciting trials are underway, and it remains to be seen whether antibody-drug conjugates beyond trastuzumab emtansine, will find their way into the treatment lines for early-stage BC. Furthermore, the integration of artificial intelligence in both diagnostics and treatment recommendation evaluation is a promising area with great potential.

Targeting LHPP in neoadjuvant chemotherapy resistance of gastric cancer: insights from single-cell and multi-omics data on tumor immune microenvironment and stemness characteristics

Gastric cancer (GC) is a highly heterogeneous and complex malignancy, often characterized by tumor stemness and immune evasion mechanisms, which contribute to a poor response to neoadjuvant chemotherapy (NAC) and treatment resistance. In this study, we performed a comprehensive analysis using single-cell and multi-omics approaches on 375 GC samples from The Cancer Genome Atlas database, along with 141 clinical samples from patients who underwent NAC. We identified key gene modules associated with stemness and immune traits, and developed a novel stem cell-immune risk score. This score effectively distinguished responders from non-responders to chemotherapy, and was significantly associated with overall survival. Through multi-omics analysis, we further elucidated the role of phospholysine phosphohistidine inorganic pyrophosphatase (LHPP) in the tumor immune microenvironment. Our findings showed that high LHPP expression was closely linked to the increased infiltration of antitumor immune cells, such as CD8+ T cells, and significantly suppressed the development of stemness characteristics in GC. Additionally, single-cell sequencing data revealed that tumor epithelial cells with low LHPP expression exhibited heightened stemness and demonstrated the strongest communication with CD8+-exhausted T cells. We also observed that LHPP inhibited stemness and chemotherapy resistance in GC cells by regulating the phosphorylation of GSK-3β. In conclusion, LHPP plays a critical regulatory role in the stemness features and tumor immune microenvironment of GC, presenting a promising biomarker and potential therapeutic target for personalized treatment of GC.

Tumor-derived arachidonic acid reprograms neutrophils to promote immune suppression and therapy resistance in triple-negative breast cancer

The combination of immune checkpoint blockade and chemotherapies is the standard of care for triple-negative breast cancer (TNBC). However, initially, responsive tumors can still develop recurrences, suggesting acquired resistance mechanisms that remain poorly understood. Herein, we discover that TNBC cells surviving anti-programmed cell death protein-1 (anti-PD-1) and chemotherapy treatment accumulate neutral lipids. Disrupting lipid droplet formation in cancer cells reverses resistance and mitigates the immunosuppressive microenvironment. Single-cell RNA sequencing reveals a subset of neutrophils exhibiting a lipid-laden phenotype similar to adjacent tumor cells. Mechanistically, tumor-derived extracellular vesicles carrying lipids, including arachidonic acid (AA), mediate neutrophil reprogramming. Blocking dietary intake of omega-6 fatty acids or inhibiting fatty acid elongation for AA synthesis restores anti-tumor immunity and re-sensitizes the resistant tumors to anti-PD-1 and chemotherapy treatment. In human patients, AA metabolism-related pathways correlates with neutrophil enrichment. Overall, we demonstrate how lipid accumulation in TNBC cells leads to immune suppression and therapy resistance.

Recent Advances in Immune Checkpoint Inhibitors for Triple-Negative Breast Cancer

While immunotherapy has transformed treatment across various cancers, its impact on breast cancer is relatively limited. Recent advances have established immunotherapy as an effective approach for triple-negative breast cancer (TNBC), an aggressive subtype with limited therapeutic targets and poor prognosis. Specifically, pembrolizumab, an immune checkpoint inhibitor (ICI), is now approved for both first-line metastatic and early-stage TNBC. In metastatic TNBC, combining ICIs with chemotherapy, particularly pembrolizumab, has demonstrated survival benefits in patients with PD-L1-positive disease. However, extending these benefits to broader populations has proven challenging, highlighting the need for better patient selection and novel strategies. Emerging approaches include combining ICIs with antibody-drug conjugates, PARP inhibitors, dual ICIs, and bispecific antibodies targeting angiogenesis and immune checkpoints. These strategies aim to overcome resistance and expand immunotherapy's efficacy beyond the PD-1/PD-L1 pathway. In early-stage disease, pembrolizumab combined with chemotherapy in the neoadjuvant setting has significantly improved pathologic complete response, event-free survival, and overall survival, establishing a new standard of care. Ongoing research aims to determine the optimal timing for ICI administration, explore less toxic chemotherapy backbones, utilize biomarkers for personalized treatment, and assess whether adding complementary treatments, such as radiation therapy for high-risk cases, can improve outcomes. This review examines the successes and setbacks of ICI use in TNBC, offering a comprehensive overview of current practices and future directions. It emphasizes optimizing ICI timing, leveraging biomarkers, and integrating novel agents to refine treatment approaches for both metastatic and early-stage TNBC. As immunotherapy continues to evolve, future research must address the unmet needs of this challenging breast cancer subtype, offering hope for improved outcomes.

Dual inhibition of TYK2 and PD-L1 boosts immune response in triple negative breast cancer

Recent studies have shown that Janus Kinase inhibitors can enhance the tumor therapeutic effect of immune checkpoint inhibitors. However, it remains to be studied whether TYK2 selective inhibitors can enhance the therapeutic effect of small molecule PD-L1 inhibitors in triple-negative breast cancer (TNBC). We verified the efficacy of the combination of the selective TYK2 inhibitor Deucravacitinib and the small molecule inhibitor of PD-L1, INCB086550, in two TNBC animal models: a syngeneic mouse model (4T1 with humanized PD-L1) and a peripheral blood mononuclear cell (PBMC)-humanized model (MDA-MB-231). Following that, we explored the regulation of immune cell activity in tumors by the combined treatment using flow cytometry. Finally, we validated the expression of genes related to the regulated immune cells through reverse transcription-PCR. Both animal models demonstrated that the addition of a TYK2 inhibitor to a PD-L1 inhibitor significantly enhanced the antitumor capabilities of mice with good safety profiles. The combined therapy significantly elevated the counts of T, B, and natural killer cells while concurrently diminishing myeloid-derived suppressor cells in the syngeneic model. Similarly, in the PBMC-humanized model, this therapy markedly augmented progenitor-like and proliferative precursor-like CD8 T cells, while effectively diminishing exhausted and terminally differentiated CD8 T cell populations. This enhanced antitumor effect is associated with the modulation of antitumor immune-related gene expression by the combined therapy. The combination of TYK2 inhibitors and immune checkpoint inhibitors is a potentially effective strategy for treating TNBC.

A system review of neoadjuvant immune checkpoint blockade for breast cancer

Background

The clinical application of immune checkpoint blockade (ICB)-based neoadjuvant therapy has been approved in breast cancer since 2021. However, no studies have evaluated its efficacy and safety in randomized and non-randomized settings. Additionally, there exists controversy about which specific subpopulation can benefit from this management strategy.

Methods

We searched MEDLINE and EMBASE databases for prospective clinical trials of ICB-based neoadjuvant therapy in breast cancer. Information regarding pathological complete response (pCR), event-free survival (EFS), overall survival (OS), and treatment-related adverse event (TRAE) were pooled to estimate the efficacy and safety. Hazard ratio, relative risk (RR) and their 95% confidence intervals (CIs) were calculated.

Results

Among 22 eligible trials including 6134 women with resectable breast cancer, there were 11 randomized studies with 5574 patients. Pooled analysis on pCR (RR, 1.38; 95% CI, 1.20-1.58; P<0.001), EFS (hazard ratio, 0.67; 95% CI, 0.54-0.81; P<0.001), and OS (hazard ratio, 0.56; 95% CI, 0.35-0.91; P=0.01) revealed that ICB-based neoadjuvant therapy was associated with favorable outcomes over conventional treatment. Moreover, the benefits of EFS were independent of PD-L1 expression (Pinteraction =0.57) and pCR (Pinteraction =0.37) in neoadjuvant immunotherapy. However, combining ICB with conventional neoadjuvant treatment significantly increased the risk of high-grade TRAE (RR, 1.06; 95% CI, 1.01-1.12; P=0.03), serious TRAE (RR, 1.57; 95% CI, 1.26-1.94; P<0.001), treatment discontinuation due to TRAE (RR, 1.47; 95% CI, 1.14-1.90; P=0.003), and potentially fatal adverse event (RR, 2.25; 95% CI, 0.80-6.31; P=0.12).

Conclusion

The combination of ICB with conventional neoadjuvant treatment is associated with favorable clinical outcomes and importantly, increased grade 3+ toxicities. Clinicians should meticulously monitor patients to minimize the risk of treatment discontinuation in individuals with potentially curable breast cancer.

Pathological complete response, histologic grade, and level of stromal tumor-infiltrating lymphocytes in ER + HER2- breast cancer

BACKGROUND

Recent trials have integrated immune checkpoint inhibitors (ICIs) into neoadjuvant chemotherapy (NAC) in patients with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer of histologic grade (HG) III. We assessed the pathological complete response (pCR) rate according to the level of stromal tumor-infiltrating lymphocytes (sTIL) and HG in patients with ER + HER2- breast cancer undergoing NAC.

METHODS

Between January 2016 and December 2023, we retrospectively identified 376 patients with ER + HER2- breast cancer who underwent NAC followed by surgery. HG and sTIL levels were examined in the biopsied samples before NAC. Multiple sTIL cutoff values as 10%, 20%, and 30% were applied.

RESULTS

Twenty-seven patients (7.2%) had HG III tumors. The pCR rate in the HG III group was 22.2%, which was significantly higher than that in the HG I/II group (4.0%) (p < 0.001). The HG III group had a higher mean sTIL level than HG I/II group (38.7% vs. 12.9%; p < 0.001). According to the sTIL levels, the pCR rate in the high sTIL group was significantly higher than that in the low sTIL group: i) cutoff of 10%, 2.4% vs. 9.5%; cutoff of 20%, 2.8% vs. 13.7%; and cutoff of 30%, 3.2% vs. 18.3%. In the high sTIL (≥ 30%) group, the pCR rate for HG III was 33.3%, whereas that for HG I/II was 13.3%.

CONCLUSIONS

High tumor grade and sTIL levels were associated with higher rates of pCR in ER + HER2- breast cancer. Our findings support that the addition to ICIs to NAC increased pCR in high-risk, HG III, ER + HER2- breast cancer and suggest that sTIL levels could be utilized to identify patients with ER + HER2- breast cancer eligible for chemoimmunotherapy.

Progesterone receptor-dependent downregulation of MHC class I promotes tumor immune evasion and growth in breast cancer

BACKGROUND

Breast cancer (BC) continues to be a major health concern with 250,000 new cases diagnosed annually in the USA, 75% of which are hormone receptor positive (HR+), expressing estrogen receptor alpha (ER) and/or the progesterone receptor (PR). Although ER-targeted therapies are available, 30% of patients will develop resistance, underscoring the need for new non-ER/estrogen-based treatments. Notably, HR+BCs exhibit poor lymphocyte infiltration and contain an immunosuppressive microenvironment, which contributes to the limited efficacy of immunotherapies in HR+BC. In this study, we demonstrate that PR/progesterone signaling reduces major histocompatibility complex (MHC) Class I expression, facilitating immune evasion and escape from immune-based clearance of PR+tumors.

METHODS

To determine the effect of PR/progesterone on MHC Class I expression, we treated human and mouse mammary tumor cell lines with progesterone and/or interferon (IFN) and measured expression of genes involved in antigen processing and presentation (APP), as well as surface MHC Class I expression. We used the OT-I/SIINFEKL model antigen system to measure the impact of progesterone on immune cell-mediated killing of modified tumor cells. We also analyzed two large BC clinical cohorts to determine how PR expression correlates with APP gene expression and MHC Class I expression in ER-positive tumors.

RESULTS

In vitro, we show that PR/progesterone signaling reduces APP gene expression and MHC class I expression in human and breast mammary tumor cell lines. PR-mediated attenuation of APP/MHC Class I expression is more pronounced in the presence of IFN. In immune cell killing assays, PR-expressing mammary tumor cells treated with progesterone are protected from immune-mediated cytotoxicity. We demonstrate that PR expression in vivo prevents immune-mediated rejection of xenoantigen-modified mammary tumor cell lines through mechanisms involving MHC Class I expression and CD8 T cells. Data analysis of two large BC cohorts reveals lower APP gene expression and MHC Class I expression in ER/PR-positive tumors compared with ER-positive/PR-negative tumors. These findings show that HR+BCs, specifically PR+tumors, downregulate APP/MHC class I machinery through PR/progesterone signaling. Use of pharmacological PR/progesterone inhibitors may reverse these effects in patients with BC, thereby improving immunosurveillance and response to immunotherapies.

New progress in imaging diagnosis and immunotherapy of breast cancer

Breast cancer (BC) is a predominant malignancy among women globally, with its etiology remaining largely elusive. Diagnosis primarily relies on invasive histopathological methods, which are often limited by sample representation and processing time. Consequently, non-invasive imaging techniques such as mammography, ultrasound, and Magnetic Resonance Imaging (MRI) are indispensable for BC screening, diagnosis, staging, and treatment monitoring. Recent advancements in imaging technologies and artificial intelligence-driven radiomics have enhanced precision medicine by enabling early detection, accurate molecular subtyping, and personalized therapeutic strategies. Despite reductions in mortality through traditional treatments, challenges like tumor heterogeneity and therapeutic resistance persist. Immunotherapies, particularly PD-1/PD-L1 inhibitors, have emerged as promising alternatives. This review explores recent developments in BC imaging diagnostics and immunotherapeutic approaches, aiming to inform clinical practices and optimize therapeutic outcomes.

Molecular determinants of response to neoadjuvant pembrolizumab plus chemotherapy in patients with high-risk, early-stage, triple-negative breast cancer: exploratory analysis of the open-label, multicohort phase 1b KEYNOTE-173 study

BACKGROUND

The multicohort, open-label, phase 1b KEYNOTE-173 study was conducted to investigate pembrolizumab plus chemotherapy as neoadjuvant therapy for triple-negative breast cancer (TNBC). This exploratory analysis evaluated features of the tumor microenvironment that might be predictive of response.

METHODS

Cell fractions from 20 paired samples collected at baseline and after one cycle of neoadjuvant pembrolizumab prior to chemotherapy initiation were analyzed by spatial localization (tumor compartment, stromal compartment, or sum of tumor and stromal compartments [total tumor]) using three six-plex immunohistochemistry panels with T-cell, myeloid cell, and natural killer cell components. Area under the receiver operating characteristic curve (AUROC) was used to assess associations between immune subsets and gene expression signatures (T-cell-inflamed gene expression profile [TcellinfGEP] and 10 non-TcellinfGEP signatures using RNA sequencing) and pathologic complete response (pCR).

RESULTS

At baseline, six immune subsets quantitated within the tumor compartment showed AUROC with 95% CIs not crossing 0.5, including CD11c+ cells (macrophage and dendritic cell [DC]: AUROC, 0.85; 95% confidence interval [CI] 0.63-1.00), CD11c+/MHCII+/CD163-/CD68- cells (DC: 0.76; 95% CI, 0.53-0.99), CD11c+/MHCII-/CD163-/CD68- cells (nonactivated/immature DC: 0.80; 95% CI 0.54-1.00), and CD11c+/CD163+ cells (M2 macrophage: 0.77; 95% CI 0.55-0.99). Other associations with pCR included baseline CD11c+/MHCII-/CD163-/CD68- (nonactivated/immature DC) within the total tumor (AUROC, 0.76; 95% CI 0.51-1.00) and the baseline CD11c/CD3 ratio within the tumor compartment (0.75; 95% CI 0.52-0.98). Changes in immune subsets following one cycle of pembrolizumab were not strongly associated with pCR. Although T-cell associations were relatively weak, specific CD8 subsets trended toward association. The AUROC for discriminating pCR based on TcellinfGEP was 0.55 (95% CI 0.25-0.85); when detrended by TcellinfGEP, AUROC varied for the non-TcellinfGEP signatures. TcellinfGEP expression trended higher in responders than in nonresponders when evaluating pCR.

CONCLUSIONS

Myeloid cell populations within the tumor compartment at baseline and TcellinfGEP show a promising trend toward an association with pCR in a small subgroup of patients with early-stage TNBC treated with neoadjuvant pembrolizumab plus chemotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02622074; registration date, December 2, 2015.

Therapeutic potential of triple-negative breast cancer immune checkpoint blockers: A 21-year bibliometric analysis

BACKGROUND

Triple-negative breast cancer (TNBC) is an aggressive metastatic subtype of BC that frequently develops chemoresistance. Immune checkpoint blockers (ICB) have led to breakthroughs in TNBC treatment. This study aimed to explore research trends and public interest in ICB interventions for TNBC.

METHODS

We searched the Web of Science Core Collection (WoSCC) database for publications related to ICB for TNBC from 2003 to 2024. VOSviewer, CiteSpace, and R package "bibliometrix" were used to analyze the characteristics of ICB publications in TNBC from a quantitative and qualitative perspective and to visualize the results to comprehensively present the research trends in this field.

RESULTS

After removing duplicates, 2698 publications were included. The New England Journal of Medicine may be the leading and influential in the field of ICB in TNBC according to data on the total number of publications, number of citations, and impact factors. Its article entitled "Atezolizumab and Nab-Paclitaxel in Advanced TNBC" is 1 of the most cited articles. Keyword analysis showed that current research hotspots in this field are tumor microenvironment, complete pathological response, neoadjuvant chemotherapy, and PARP inhibitors. Future research hotspots may include the PD-L1 inhibitor durvalumab and antibody-drug conjugates (ADC).

CONCLUSIONS

This study revealed that ICB therapy for TNBC is a rapidly evolving and high-profile topic. Future research should focus on the optimal selection of different targets for ICB in combination with neoadjuvant chemotherapy, ADC, and poly ADP-ribose polymerase inhibitors to treat TNBC.

Profiling Multiple CD8+ T-cell Functional Dimensions Enhances Breast Cancer Immune Assessment

CD8+ T-cell abundance is insufficient to assess antitumor immunity and shows poor performance in predicting breast cancer prognosis and immunotherapy response, presumably owing to the complexity of CD8+ T-cell functionalities. Although single-cell RNA sequencing can dissect the multifaceted functions of CD8+ T cells for better immune assessment, its clinical application is limited. In this study, we developed bulk RNA sequencing-based FuncDimen models from integrative analysis of single-cell RNA sequencing and matched bulk RNA sequencing data to evaluate CD8+ T-cell functionalities across five dimensions: tumor reactivity, cytotoxicity, IFNγ secretion, proliferation, and apoptosis. The FuncDimen models quantifying different functional dimensions of CD8+ T cells were validated in our breast cancer cohort and external databases using immunofluorescence and imaging mass cytometry. We calculated the FuncAggre score by weighted aggregation of all five FuncDimen models to encapsulate the overall antitumor immunity. In our breast cancer cohort and external databases, the FuncAggre score demonstrated superior predictive performance for breast cancer prognosis (time-dependent AUC: 0.56-0.70) and immunotherapy response (AUC: 0.71-0.83) over other immune biomarkers, regardless of the breast cancer molecular subtype. Together, the FuncDimen models offer a refined assessment of antitumor immunity mediated by CD8+ T cells in the clinic, enhancing prognostic prediction and aiding personalized immunotherapy in breast cancer.

Intratumoral Injection of mRNA-2752 and Pembrolizumab for High-Risk Ductal Carcinoma In Situ: A Phase 1 Nonrandomized Clinical Trial

Importance

Intratumoral immunotherapy that leverages the biological characteristics of high-risk ductal carcinoma in situ (DCIS) may be able to reduce the extent of surgical treatment and provide an alternative approach to improve patient outcomes.

Objective

To determine if combination intratumoral immunotherapy can activate immune cells to shrink or eliminate high-risk DCIS.

Design, Setting, and Participants

This phase 1 open-label nonrandomized clinical trial at a single academic center tested the safety and efficacy of intratumoral immunotherapy in patients with high-risk DCIS, defined as at least 2 of the following present: younger than 45 years, tumor size greater than 5 cm, high-grade, palpable mass, hormone receptor (HR)-negative, or ERBB2-positive. Patients were enrolled between June 8, 2021, and December 13, 2022.

Intervention

Pembrolizumab (anti-programmed cell death protein 1), dose ranging from 2 mg to 8 mg, and mRNA-2752 (a combination of interleukin [IL]-23, IL-36γ, and OX40L mRNAs), dose ranging from 1 mg to 4 mg, delivered intratumorally, with 2 to 4 doses given 2 to 3 weeks apart.

Main Outcomes and Measures

The primary objective was to evaluate the safety and tolerability of intratumoral injections of pembrolizumab and mRNA-2752. The secondary objectives were to assess radiologic and pathological responses and immunological and histological differences in the posttreatment tumor microenvironment.

Results

Ten female patients with high-risk DCIS (median [range] age, 46 [35-80] years) were enrolled. The median (range) tumor size was 5.3 (1.0-10.0) cm. Five tumors were HR-negative ERBB2-positive; 2 HR-negative ERBB2-negative; 2 HR-positive ERBB2-negative; and 1 HR-positive ERBB2-positive. Of all treated patients, 8 of 10 responded to treatment, and all 8 patients had ERBB2-positive or HR-negative DCIS. Three patients had complete responses. Three patients with negative posttreatment core biopsy results declined surgery and remained disease-free after 1 to 2 years. Multiplex immunofluorescence staining demonstrated that high baseline levels of tumor-infiltrating lymphocytes and programmed cell death ligand 1-positive cells (immune or tumor) were associated with a better treatment response. All patients experienced up to 1 week of fever, malaise, flulike symptoms, axillary adenopathy, erythema, injection site swelling, and swelling in the breast. One patient had intermittent urticaria for 3 months. The dose was serially reduced from 8 mg to 2 mg for pembrolizumab and 4 mg to 1 mg for mRNA-2752 to improve tolerability. The final recommended combination dose is pembrolizumab, 4 mg, with mRNA-2752, 1 mg.

Conclusions and Relevance

In this phase 1 nonrandomized clinical trial, the results suggest that intratumoral injections of pembrolizumab and mRNA-2752 are safe and may induce rapid regression of high-risk DCIS with high immune infiltrates. These findings warrant additional investigation, and studies are ongoing.

Trial Registration

ClinicalTrials.gov Identifier: NCT02872025.

Inherent PD-L1 22C3 Expression in Alveolar Macrophages Impacts the Combined Positive Score Status in Breast Cancer With Pulmonary Metastasis

PURPOSE

This study aimed to determine the impact of inherent programmed death-ligand 1 (PD-L1)-expressing alveolar macrophages (AMs) on the combined positive score (CPS) of PD-L1 (22C3) in metastatic breast cancer in the lungs.

METHODS

A total of 87 patients with pulmonary metastases of breast cancer were included in this study. Immunohistochemical staining of various PD-L1 antibodies was performed. The CPSs and CPSs excluding the number of PD-L1 positive AMs [CPS(NAM)s] with PD-L1 (22C3) were determined and compared.

RESULTS

Among 87 enrolled patients, 22 had luminal A breast cancer, 24 had luminal B breast cancer, 13 had HER-2-positive breast cancer, and 28 had triple-negative breast cancer (TNBC). CPSs ≥ 10 was observed only in luminal B (12.5%) and TNBC (35.7%) subtypes (p < 0.001), whereas CPS(NAM)s ≥ 10 was observed only in TNBC (14.3%) (p = 0.011). Changes from the CPS-positive to the CPS(NAM)-negative status occurred in nine cases (10.3%), with significantly higher proportions being observed in the luminal B (12.5%) and TNBC (21.4%) subtypes (p = 0.007). Tumors showing changes from the CPS-positive to the CPS(NAM)-negative status were larger (p < 0.001); similar findings were observed in the TNBC subgroup (p = 0.001).

CONCLUSION

The inclusion of PD-L1 expressing AMs leads to differences in CPS positivity, especially in large TNBC subtype tumors.

T-cell immune checkpoint inhibition plus hypomethylation for locally advanced HER2-negative breast cancer: a phase 2 neoadjuvant window trial of decitabine and pembrolizumab followed by standard neoadjuvant chemotherapy

BACKGROUND

Higher levels of tumor-infiltrating lymphocytes (TILs) in breast cancers are associated with increased likelihood of pathologic complete response (pCR) to chemotherapy. DNA methyltransferase inhibitors (DNMTi) can augment immune responses to cancers, decreasing myeloid-derived suppressor cells (MDSCs) and increasing T lymphocyte responsiveness. We have shown that the DNMTi decitabine augments the effectiveness of immunotherapy using murine triple-negative breast cancer (TNBC) models. The primary objective was to determine whether DNMTi+immune checkpoint blockade would increase stromal TIL (sTIL) in primary breast cancers before neoadjuvant chemotherapy (NCT).

METHODS

In a phase 2 study (NCT02957968), patients with human epidermal growth factor receptor 2-negative breast cancer received window immunotherapy-decitabine (15 mg/m2×4 doses over 5 days) followed by 2 doses of pembrolizumab (200 mg, 2 weeks apart)-before starting NCT. Biopsies before and after window immunotherapy quantified TILs and programmed death-ligand 1 (PD-L1) expression. Patients proceeded to NCT and tumor resection per standard of care. Mid-study, results of the KEYNOTE 522 trial led to patients with TNBC receiving additional pembrolizumab concurrently with standard NCT and in the adjuvant setting.

RESULTS

46 patients (median age 54.5 years, range 28-72; 71.7% white, 28.3% black; 100% female) were treated. 21 patients had TNBC and received neither neoadjuvant pembrolizumab concurrently with NCT nor adjuvant pembrolizumab (Cohort A), 7 patients had TNBC and did receive concurrent and/or adjuvant pembrolizumab (Cohort A2), and 18 patients were estrogen receptor positive and/or progesterone receptor positive and received neither concurrent nor adjuvant pembrolizumab (Cohort B). Blood samples collected after decitabine administration before pembrolizumab showed a 59% decrease (p<0.01) in monocytic MDSCs compared with baseline. 38 patients had paired biopsies for sTIL and 37 for PD-L1 evaluation. Cohorts A/A2 experienced an sTIL increase of 6.1% (p<0.008); Cohort B experienced an sTIL increase of 8.3% (p=0.006). PD-L1 expression increased by 73.9% (p<0.01). 14 of 43 patients (32.6%) who proceeded to resection achieved pCR (n=11 of 27 (40.1%) in Cohorts A/A2 and n=3 of 16 (18.8%) in Cohort B). The most frequently reported immune-related adverse events were adrenal insufficiency (AI) (n=6, 13.0%), maculopapular rash (n=3, 6.5%), and hypothyroidism (n=3, 6.5%). Five of the six AI instances were at least partially attributable to hypophysitis/pituitary dysfunction, and one remains uncertain.

CONCLUSIONS

Treatment in the pre-neoadjuvant window with decitabine and pembrolizumab could sensitize breast cancers to standard NCT by recruitment of TILs to the tumor tissue. The treatment was well-tolerated.

TRIAL REGISTRATION NUMBER

NCT02957968.

Breast cancer: pathogenesis and treatments

Breast cancer, characterized by unique epidemiological patterns and significant heterogeneity, remains one of the leading causes of malignancy-related deaths in women. The increasingly nuanced molecular subtypes of breast cancer have enhanced the comprehension and precision treatment of this disease. The mechanisms of tumorigenesis and progression of breast cancer have been central to scientific research, with investigations spanning various perspectives such as tumor stemness, intra-tumoral microbiota, and circadian rhythms. Technological advancements, particularly those integrated with artificial intelligence, have significantly improved the accuracy of breast cancer detection and diagnosis. The emergence of novel therapeutic concepts and drugs represents a paradigm shift towards personalized medicine. Evidence suggests that optimal diagnosis and treatment models tailored to individual patient risk and expected subtypes are crucial, supporting the era of precision oncology for breast cancer. Despite the rapid advancements in oncology and the increasing emphasis on the clinical precision treatment of breast cancer, a comprehensive update and summary of the panoramic knowledge related to this disease are needed. In this review, we provide a thorough overview of the global status of breast cancer, including its epidemiology, risk factors, pathophysiology, and molecular subtyping. Additionally, we elaborate on the latest research into mechanisms contributing to breast cancer progression, emerging treatment strategies, and long-term patient management. This review offers valuable insights into the latest advancements in Breast Cancer Research, thereby facilitating future progress in both basic research and clinical application.

Advancements in clinical research and emerging therapies for triple-negative breast cancer treatment

Triple-negative breast cancer (TNBC), defined by the lack of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 (HER2) expression, is acknowledged as the most aggressive form of breast cancer (BC), comprising 15%-20% of all primary cases. Despite the prevalence of TNBC, effective and well-tolerated targeted therapies remain limited, with chemotherapy continuing to be the mainstay of treatment. However, the horizon is brightened by recent advancements in immunotherapy and antibody-drug conjugates (ADCs), which have garnered the U.S. Food and Drug Administration (FDA) approval for various stages of TNBC. Poly (ADP-ribose) polymerase inhibitors (PARPi), particularly for TNBC with BRCA mutations, present a promising avenue, albeit with the challenge of resistance that must be addressed. The success of phosphoinositide-3 kinase (PI3K) pathway inhibitors in hormone receptor (HR)-positive BC suggests potential applicability in TNBC, spurring optimism within the research community. This review endeavors to offer a comprehensive synthesis of both established and cutting-edge targeted therapies for TNBC. We delve into the specifics of PARPi, androgen receptor (AR) inhibitors, Cancer stem cells (CSCs), PI3K/Protein Kinase B (AKT)/mammalian target of rapamycin (mTOR), the transforming growth factor-beta (TGF-β), Ntoch, Wnt/β-catenin, hedgehog (Hh) pathway inhibitors, Epigenetic target-mediated drug delivery, ADCs, immune checkpoint inhibitors (ICIs)and novel immunotherapeutic solutions, contextualizing TNBC within current treatment paradigms. By elucidating the mechanisms of these drugs and their prospective clinical applications, we aim to shed light on the challenges and underscore the beacon of hope that translational research and innovative therapies represent for the oncology field.

Neoadjuvant nivolumab and chemotherapy in early estrogen receptor-positive breast cancer: a randomized phase 3 trial

Patients with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-) primary breast cancer (BC) have low pathological complete response (pCR) rates with neoadjuvant chemotherapy. A subset of ER+/HER2- BC contains dense lymphocytic infiltration. We hypothesized that addition of an anti-programmed death 1 agent may increase pCR rates in this BC subtype. We conducted a randomized, multicenter, double-blind phase 3 trial to investigate the benefit of adding nivolumab to neoadjuvant chemotherapy in patients with newly diagnosed, high-risk, grade 3 or 2 (ER 1 to ≤10%) ER+/HER2- primary BC. In total, 510 patients were randomized to receive anthracycline and taxane-based chemotherapy with either intravenous nivolumab or placebo. The primary endpoint of pCR was significantly higher in the nivolumab arm compared with placebo (24.5% versus 13.8%; P = 0.0021), with greater benefit observed in patients with programmed death ligand 1-positive tumors (VENTANA SP142 ≥1%: 44.3% versus 20.2% respectively). There were no new safety signals identified. Of the five deaths that occurred in the nivolumab arm, two were related to study drug toxicity; no deaths occurred in the placebo arm. Adding nivolumab to neoadjuvant chemotherapy significantly increased pCR rates in high-risk, early-stage ER+/HER2- BC, particularly among patients with higher stromal tumor-infiltrating lymphocyte levels or programmed death ligand 1 expression, suggesting a new treatment paradigm that emphasizes the role of immunotherapy and T cell immunosurveillance in luminal disease. Clinical trials.gov identifier: NCT04109066.

Real-World Outcomes with the KEYNOTE-522 Regimen in Early-Stage Triple-Negative Breast Cancer

BACKGROUND

This study aimed to determine if the neoadjuvant (NAT) KEYNOTE-522 regimen was associated with higher rates of pathologic complete response (pCR), corresponding to higher rates of breast conservation therapy (BCT) in early-stage triple-negative breast cancer (TNBC) patients.

PATIENTS AND METHODS

Stage II-III TNBC patients diagnosed between 2019 and 2022 who underwent NAT were analyzed retrospectively. NAT with KEYNOTE-522 versus control NAT were compared for rates of BCT, axillary node dissection (ALND), pCR, and survival outcomes. The prevalence of immune-related adverse events (irAE) from chemoimmunotherapy was recorded.

RESULTS

Of 240 patients identified: 86 received KEYNOTE-522 and 154 received control. The frequency of pCR was significantly higher in KEYNOTE versus the control cohort, 59.3% and 33.1%, respectively (p = 0.001). There was no significant difference in the rate of BCT between the control (33.1%) and the KEYNOTE-522 (32.1%) groups (p = 0.47). Rates of ALND were significantly lower with KEYNOTE-522 (25.6%) as compared with control (39.6%); p = 0.03. The rate of development of grade 2 or higher irAEs was 34.9%. At a median follow-up of 2.4 years, there was no difference in survival outcomes. BRCA1 patients had high rates of pCR regardless of treatment group, KEYNOTE-522: 80.0% (4/5) and control: 75% (9/12), (p = 1).

CONCLUSION

This real-world evidence supports the use of the KEYNOTE-522 regimen in patients with early-stage TNBC given the higher pCR rate and corresponding decrease in the rate of ALND. The majority of patients in both NAT cohorts became BCT eligible, but the rate of BCT did not differ between the two groups.

Overall Survival and Economic Impact of Triple-Negative Breast Cancer in Brazilian Public Health Care: A Real-World Study

PURPOSE

Triple-negative breast cancer (TNBC) presents notable treatment difficulties, especially in the public health care systems of low- and middle-income countries where access to advanced therapies is restricted. This study investigates TNBC's clinical, epidemiologic, and economic effects on survival within Brazil's public health care system.

METHODS

We conducted a retrospective cohort study of patients with TNBC treated between 2010 and 2019. Overall survival (OS) rates by stage were analyzed across various patient groups, including those receiving neoadjuvant or adjuvant treatment, patients with or without complete pathologic response, Black and non-Black patients, and those treated with or without carboplatin-based therapy. Cox proportional hazards models were applied to estimate hazard ratios (HRs) with 95% CIs, and annual treatment costs were calculated per stage.

RESULTS

Among 1,266 patients with TNBC, 710 met eligibility criteria. Kaplan-Meier analysis indicated stage II patients had a 47% lower mortality risk than stage III (HR, 0.53 [95% CI, 0.33 to 0.85]; P = .009). Patients in the adjuvant treatment group had a reduced risk (HR, 0.48 [95% CI, 0.34 to 0.69]) compared with the neoadjuvant group. Achieving complete pathologic response (pCR) greatly improved OS (HR, 0.21 [95% CI, 0.11 to 0.43]; P < .001). Black patients had better survival rates than non-Black (HR, 0.58 [95% CI, 0.40 to 0.86]; P = .006). Carboplatin use did not significantly affect OS (HR, 0.96 [95% CI, 0.65 to 1.43]; P = .857). The average monthly cost for systemic TNBC treatment increased with disease progression, from $101.87 in US dollars (USD) for stage I to $314.77 USD for stage IV second-line therapy.

CONCLUSION

This study provides insight into TNBC in Brazil's public health system, showing that OS decreases with disease progression but is higher among Black patients. pCR and adjuvant therapy improve survival, although costs increase significantly at advanced stages, highlighting the economic burden of late-stage TNBC management.

High tumor glucocorticoid receptor expression in early-stage, triple-negative breast cancer is associated with increased T-regulatory cell infiltration

PURPOSE

In early-stage, triple-negative breast cancer (TNBC), immune cell infiltration contributes to cancer cell survival, tumor invasion, and metastasis. High TNBC glucocorticoid receptor (GR) expression in early-stage TNBC is associated with poor long-term outcomes; it is unknown if high GR expression is associated with an immunosuppressed tumor microenvironment. We hypothesized that high tumor GR expression would be associated with an immune-suppressed tumor microenvironment, which could thus account for the poor prognosis observed in GR-positive TNBC.

METHODS

Formalin fixed-paraffin embedded tissue (n = 47) from patients diagnosed with early-stage TNBC from The University of Chicago (2002-2014) were evaluated for both tumor cell anti-GR immunohistochemistry and for infiltrating immune cells by immunofluorescence. Multiplexed antibodies were used to enumerate CD8+, FOXP3+, and BATF3+ immune cells infiltrating within pan-cytokeratin positive tumor cell regions of interest, and nonparametric tests compared absolute counts of each of these tumor-infiltrating immune cell types.

RESULTS

The average age of patients represented in this study was 52 years, and 63% self-identified as Black. There was no significant association between tumor GR expression and age, race, or clinical stage at diagnosis. Compared to GR-low tumors, high GR expression in early-stage, treatment-naïve TNBC was associated with relatively increased numbers of immunosuppressive FOXP3 + regulatory T cells (p = 0.046) and BATF3+immune cells (p = 0.021). While there was a positive correlation with high GR expression and CD8+ cell infiltration, it was not significant (p = 0.068). The ratio of CD8+/FOXP3+cells was also not significant (p = 0.24).

CONCLUSIONS

These data support the hypothesis that in early-stage TNBC, high GR expression is significantly associated with infiltration of immunosuppressive regulatory T cells, suggesting a tumor-intrinsic role in shaping the immunosuppressive immune cell milieu. Furthermore, suppression of GR activity may regulate the tumor immune microenvironment and improve long-term outcomes in GR-high TNBC.

Pathologic complete response (pCR) rates for patients with HR+/HER2- high-risk, early-stage breast cancer (EBC) by clinical and molecular features in the phase II I-SPY2 clinical trial

BACKGROUND

Hormone receptor-positive (HR+), human epidermal growth factor receptor 2 (HER2)-negative early-stage breast cancer (EBC) is a heterogenous disease. Identification of better clinical and molecular biomarkers is essential to guide optimal therapy for each patient.

PATIENTS AND METHODS

We analyzed rates of pathologic complete response (pCR) and distant recurrence-free survival (DRFS) for patients with HR+/HER2-negative EBC in eight neoadjuvant arms in the I-SPY2 trial by clinical/molecular features: age, stage, histology, percentage estrogen receptor (ER) positivity, ER/progesterone receptor status, MammaPrint (MP)-High1 (0 to -0.57) versus MP-High2 (<-0.57), BluePrint (BP)-Luminal-type versus BP-Basal-type, and ImPrint immune signature. We quantified the clinical/molecular heterogeneity, assessed overlap among these biomarkers, and evaluated associations with pCR and DRFS.

RESULTS

Three hundred and seventy-nine patients with HR+/HER2-negative EBC were included in this analysis, with an observed pCR rate of 17% across treatment arms. pCR rates were higher in patients with stage II versus III disease (21% versus 9%, P = 0.0013), ductal versus lobular histology (19% versus 11%, P = 0.049), lower %ER positivity (≤66% versus >66%) (35% versus 9%, P = 3.4E-09), MP-High2 versus MP-High1 disease (31% versus 11%, P = 1.1E-05), BP-Basal-type versus BP-Luminal-type disease (34% versus 10%, P = 1.62E-07), and ImPrint-positive versus -negative disease (38% versus 10%, P = 1.64E-09). Patients with lower %ER were more likely to have MP-High2 and BP-Basal-type disease. At a median follow-up of 4.8 years, patients who achieved pCR had excellent outcomes irrespective of clinical/molecular features. Among patients who did not achieve pCR, DRFS events were more frequent in patients with MP-High2 and BP-Basal-type disease than those with MP-High1 and BP-Luminal-type disease.

CONCLUSIONS

Among patients with high molecular-risk HR+/HER2-negative EBC, the MP-High2, BP-Basal-type, and ImPrint-positive signatures identified a partially overlapping subset of patients who were more likely to achieve pCR in response to neoadjuvant chemotherapy ± targeted agents or immunotherapy compared to patients with MP-High1, BP-Luminal-type, and ImPrint-negative disease. I-SPY2.2 is incorporating the use of these biomarkers to molecularly define specific patient populations and optimize treatment selection.

Pembrolizumab and chemotherapy in high-risk, early-stage, ER+/HER2- breast cancer: a randomized phase 3 trial

Addition of pembrolizumab to neoadjuvant chemotherapy followed by adjuvant pembrolizumab improved outcomes in patients with high-risk, early-stage, triple-negative breast cancer. However, whether the addition of neoadjuvant pembrolizumab to chemotherapy would improve outcomes in high-risk, early-stage, estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) breast cancer remains unclear. We conducted a double-blind, placebo-controlled phase 3 study (KEYNOTE-756) in which patients with previously untreated ER+/HER2- grade 3 high-risk invasive breast cancer (T1c-2 (≥2 cm), cN1-2 or T3-4, cN0-2) were randomly assigned (1:1) to neoadjuvant pembrolizumab 200 mg or placebo Q3W given with paclitaxel QW for 12 weeks, followed by four cycles of doxorubicin or epirubicin plus cyclophosphamide Q2W or Q3W. After surgery (with/without adjuvant radiation therapy), patients received adjuvant pembrolizumab or placebo for nine cycles plus adjuvant endocrine therapy. Dual primary endpoints were pathological complete response and event-free survival in the intention-to-treat population. In total, 635 patients were assigned to the pembrolizumab-chemotherapy arm and 643 to the placebo-chemotherapy arm. At the study's prespecified first interim analysis, the pathological complete response rate was 24.3% (95% confidence interval (CI), 21.0-27.8%) in the pembrolizumab-chemotherapy arm and 15.6% (95% CI, 12.8-18.6%) in the placebo-chemotherapy arm (estimated treatment difference, 8.5 percentage points; 95% CI, 4.2-12.8; P = 0.00005). Event-free survival was not mature in this analysis. During the neoadjuvant phase, treatment-related adverse events of grade ≥3 were reported in 52.5% and 46.4% of patients in the pembrolizumab-chemotherapy and placebo-chemotherapy arms, respectively. In summary, the addition of pembrolizumab to neoadjuvant chemotherapy significantly improved the pathological complete response rate in patients with high-risk, early-stage ER+/HER2- breast cancer. Safety was consistent with the known profiles of each study treatment. Follow-up continues for event-free survival. ClinicalTrials.gov identifier: NCT03725059 .

Hormone Receptor-Positive HER2-Negative/MammaPrint High-2 Breast Cancers Closely Resemble Triple-Negative Breast Cancers

PURPOSE

The MammaPrint (MP) prognostic assay categorizes breast cancers into high- and low-risk subgroups, and the high-risk group can be further subdivided into high-1 (MP-H1), and very high-risk high-2 (MP-H2). The aim of this analysis was to assess clinical and molecular differences between the hormone receptor-positive (HR+)/HER2-negative MP-H1, -H2, and triple-negative (TN) MP-H1 and -H2 cancers.

EXPERIMENTAL DESIGN

Pretreatment gene expression data from 742 HER2-negative breast cancers enrolled in the I-SPY2 neoadjuvant trial were used. Prognostic risk categories were assigned using the MP assay. Transcriptional similarities across the four receptor and prognostic groups were assessed using principal component analyses and by identifying differentially expressed genes. We also examined pathologic complete response rates and event-free survivals by risk group.

RESULTS

Principal component analysis showed that HR+/MP-H2 tumors clustered with TN/MP-H2 cancers. Only 125 genes showed differential expression between the HR+/MP-H2 and TN/MP-H2 cancers, whereas 1,465 genes were differentially expressed between HR+/MP-H2 and -H1. Gene set analysis revealed similarly high expression of cell cycle, DNA repair, and immune infiltration-related pathways in HR+/MP-H2 and TN/MP-H2 cancers. HR+/MP-H2 cancers also showed low estrogen receptor-related gene expression. Pathologic complete response rates were similarly high in TN/MP-H2 and HR+/MP-H2 cancers (42% vs. 30.5%; P = 0.11), and MP-H2 cancers with residual cancer had similarly poor event-free survival regardless of estrogen receptor status.

CONCLUSIONS

In conclusion, HR+/MP-H2 cancers closely resemble TN breast cancers in transcriptional and clinical features and benefit from similar treatment strategies.

Comparative efficacy of anthracycline-free and anthracycline-containing neoadjuvant chemoimmunotherapy regimens for triple-negative breast cancer

BACKGROUND

The selection of appropriate chemotherapy backbone agents in combination with neoadjuvant immunotherapy for triple-negative breast cancer (TNBC) remains unclear. Herein, we aimed to evaluate the efficacy and safety of anthracycline-free and anthracycline-containing regimens coupled with neoadjuvant immunotherapy.

METHOD

This retrospective study included 87 patients with TBNC who received neoadjuvant immunotherapy combined with various chemotherapy regimens at three research centers from November 2020 to November 2023. The primary objective was pathological complete response (pCR), while secondary objectives included overall response rates, event-free survival (EFS), and the incidence of adverse events. A subgroup analysis was performed to delineate patients who may substantially benefit from distinct therapeutic strategies.

RESULTS

Coupled with immunotherapy, anthracycline-free regimens achieved comparable pCR rates (55.1 % vs. 51.4 %; Odds ratio, 1.16; 95 % confidence interval [CI], 0.49-2.74; p = 0.73) and EFS (Hazard ratio, 0.66; 95 % CI, 0.18-2.45; p = 0.53) to anthracycline-containing regimens. According to subgroup analyses, the tumor stage (p = 0.017) and lymph node stage (p = 0.011) exhibit contradictory predictive power for the pCR rate of anthracycline-free regimens when compared with that of anthracycline-containing regimens. Specifically, anthracycline-free regimens yielded significantly higher pCR rates in patients without lymph node metastasis than anthracycline-containing regimens (p = 0.021). Pooled analyses further confirmed the results of both total and subgroup analyses. Most adverse events were grades 1-2, and no new adverse reactions were observed.

CONCLUSION

Anthracycline-free neoadjuvant chemotherapy regimens could serve as an effective and safe alternative immunotherapy partner for patients with TNBC, particularly in those without lymph node metastasis.

Neoadjuvant chemoimmunotherapy in resectable locally advanced oral squamous cell carcinoma: a single-center retrospective cohort study

BACKGROUND

Surgery and postoperative adjuvant therapy is the standard treatment for locally advanced resectable oral squamous cell carcinoma (OSCC), while neoadjuvant chemoimmunotherapy (NACI) is believed to lead to better outcomes. This study aims to investigate the effectiveness of NACI regimens in treating locally advanced resectable OSCC.

MATERIALS AND METHODS

Patients diagnosed with locally advanced resectable OSCC who received NACI and non-NACI were reviewed between December 2020 and June 2022 in our single center. The pathologic response was evaluated to the efficacy of NACI treatment. Adverse events apparently related to NACI treatment were graded by Common Terminology Criteria for Adverse Events, version 5.0. The disease-free survival (DFS) and overall survival (OS) rate were assessed.

RESULTS

Our analysis involved 104 patients who received NACI. Notably, the pathological complete response rate was 47.1%, and the major pathological response (MPR) rate was 65.4%. The top three grade 1-2 treatment-related adverse events (TRAEs) were alopecia (104; 100%), anemia (81; 77.9%), and pruritus (62; 59.6%). Importantly, patients achieving MPR exhibited higher programmed cell death-ligand 1 (PD-L1) combined positive scores (CPS). The diagnostic value of CPS as a biomarker for NACI efficacy was enhanced when combined with total cholesterol level. The 3-year estimated DFS rates were 89.0% in the NACI cohort compared to 60.8% in the non-NACI cohort, while the 3-year estimated OS rates were 91.3 versus 64.0%, respectively.

CONCLUSIONS

The NACI treatment showed safe and encouragingly efficacious for locally advanced resectable OSCC patients. The high response rates and favorable prognosis suggest this approach as a potential treatment option. Prospective randomized controlled trials are needed to further validate these findings.

Estrogen Signaling in Early-Stage Breast Cancer: Impact on Neoadjuvant Chemotherapy and Immunotherapy

Neoadjuvant chemoimmunotherapy (NACIT) has been shown to improve pathologic complete response (pCR) rates and survival outcomes in stage II-III triple-negative breast cancer (TNBC). Promising pCR rate improvements have also been documented for selected patients with estrogen receptor-positive (ER+) human epidermal growth factor receptor 2-negative (HER2-) breast cancer (BC). However, one size does not fit all and predicting which patients will benefit from NACIT remains challenging. Accurate predictions would be useful to minimize immune-related toxicity, which can be severe, irreversible, and potentially impact fertility and quality of life, and to identify patients in need of alternative treatments. This review aims to capitalize on the existing translational and clinical evidence on predictors of treatment response in patients with early-stage BC treated with neoadjuvant chemotherapy (NACT) and NACIT. It summarizes evidence suggesting that NACT/NACIT effectiveness may correlate with pre-treatment tumor characteristics, including mutational profiles, ER expression and signaling, immune cell presence and spatial organization, specific gene signatures, and the levels of proliferating versus quiescent cancer cells. However, the predominantly qualitative and descriptive nature of many studies highlights the challenges in integrating various potential response determinants into a validated, comprehensive, and multimodal predictive model. The potential of novel multi-modal approaches, such as those based on artificial intelligence, to overcome current challenges remains unclear, as these tools are not free from bias and shortcut learning. Despite these limitations, the rapid evolution of these technologies, coupled with further efforts in basic and translational research, holds promise for improving treatment outcome predictions in early HER2- BC.

PRECISE: Preoperative Radiation Therapy to Elicit Critical Immune Stimulating Effects-A Phase 2 Clinical Trial

PURPOSE

Radiation therapy is an underinvestigated tool for priming the immune system in intact human breast cancers. We sought here to investigate if a preoperative radiation therapy boost delivered was associated with a significant change in tumor-infiltrating lymphocytes (TILs) in the tumor in estrogen receptor positive, HER2Neu nonamplified breast cancers.

METHODS AND MATERIALS

A total of 20 patients were enrolled in a phase 2 clinical trial and received either 7.5 Gy × 1 fraction or 2 Gy × 5 fractions, completed 6 to 8 days before surgery. Percent stromal TILs were evaluated on hematoxylin and eosin-stained samples. Short-term safety was assessed based on time to surgery, toxicities, and cosmesis up to 6 months after boost.

RESULTS

Stromal TIL increased 6 to 8 days after completion of boost radiation therapy (median 3.0 [IQR, 1.0-6.5]) before radiation therapy versus median 5.0 (IQR, 1.5-8.0) after radiation therapy, P = .0037. Zero grade ≥3 toxicities up to 6 months after boost were experienced. In all, 94% (16/17) patients with 6-month follow-up cosmetic assessment after breast conservation had good-excellent cosmesis by physician assessment.

CONCLUSION

In this phase 2 trial, preoperative radiation therapy boost resulted in a short-term increase in stromal TIL with minimal toxicities. Preoperative breast radiation therapy appears to be safe and may be a feasible means for priming the tumor microenvironment.

Nomogram Prediction of Response to Neoadjuvant Chemotherapy Plus Pembrolizumab in Locally Advanced Hypopharyngeal Squamous Cell Carcinoma

IMPORTANCE

The objective response (ORR) rate in patients with locally advanced hypopharyngeal squamous cell-carcinoma (LA-HPSCC) following neoadjuvant chemotherapy (NACT) of albumin-bound paclitaxel plus carboplatin is low. At present, it is unclear whether the addition of pembrolizumab could increase the ORR or not.

OBJECTIVE

To investigate whether the addition of pembrolizumab could increase the ORR, and to develop a nomogram to predict the response of pembrolizumab addition.

DESIGN

Retrospective cohort study.

SETTING

This study was conducted at a single institution.

PARTICIPANTS

This study included 129 patients who conformed to the inclusion criteria.

INTERVENTION OR EXPOSURES

NACT with or without pembrolizumab for patients with LA-HPSCC.

MAIN OUTCOME MEASURES

The ORR was analyzed according to the RECIST 1.1 criteria and a nomogram was developed based on least absolute shrinkage and selection operator and multivariable Cox regression analysis. Predictive accuracy and discriminative ability of the nomogram were evaluated by receiver operating characteristics, precision recall, calibration curves, and decision curve analysis.

RESULTS

Eighty-two patients received NACT and 47 also received pembrolizumab. ORR was higher in patients receiving additional pembrolizumab (66.0% vs 47.6%, χ2 = 4.074, P = .044). The nomogram identified pretreatment levels of lymphocytes and red blood cells as independent predictors of a high ORR, while basophil levels were an independent predictor of a low ORR. Calibration curve showed that the nomogram-based predictions corresponded well with actual observations. C-index of the nomogram was 0.925 (0.848-1.002) and the area under curve was 0.925. Decision curve analysis affirmed that the nomogram had important clinical value.

CONCLUSIONS AND RELEVANCE

Pembrolizumab could improve the ORR in LA-HPSCC patients treated with NACT. Furthermore, a risk-prediction nomogram incorporating readily assessable routine pretreatment blood parameters can accurately estimate the response to NACT with pembrolizumab, leading to precise treatment and minimizing the waste of medical resources.

A roadmap to reduce the incidence and mortality of breast cancer by rethinking our approach to women's health

Despite progress, breast cancer remains the most feared disease among women. In the USA alone, the incidence is now almost 300,000 new cancers per year, a rate that has nearly doubled in the last 30 years. Most women survive, but over 40,000 women a year still die of their disease [99]. It is the most diagnosed cancer among women and the second leading cause of cancer death. Important disparities exist in breast cancer outcomes among African American women, where women die of breast cancer at higher rates, are diagnosed younger, and at a more advanced stage. We are proposing a radical shift in our thinking about breast cancer prevention with an aspiration to dramatically lower breast cancer incidence. Most breast cancers are driven by steroid hormones. Throughout the life course, women are offered an array of hormonal treatments for menstrual cycle control, family planning, in vitro fertilization, postpartum weaning, and menopausal symptom management. There are mixed data on the extent to which each of these may contribute to increased or decreased risk for breast cancer. These endocrine manipulations could represent a great opportunity to potentially reduce breast cancer incidence and improve quality of life for survivors. To date, they have not been designed to explicitly reduce breast cancer risk. A new holistic approach will require scientists, drug developers, breast oncologists, obstetricians, gynecologists, endocrinologists, radiologists, and family medicine/internists to work together toward the common goal of reducing breast cancer risk while addressing other critical issues in women's health.

Tumor microenvironment and immunotherapy for triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a subtype of breast cancer known for its high aggressiveness and poor prognosis. Conventional treatment of TNBC is challenging due to its heterogeneity and lack of clear targets. Recent advancements in immunotherapy have shown promise in treating TNBC, with immune checkpoint therapy playing a significant role in comprehensive treatment plans. The tumor microenvironment (TME), comprising immune cells, stromal cells, and various cytokines, plays a crucial role in TNBC progression and response to immunotherapy. The high presence of tumor-infiltrating lymphocytes and immune checkpoint proteins in TNBC indicates the potential of immunotherapeutic strategies. However, the complexity of the TME, while offering therapeutic targets, requires further exploration of its multiple roles in immunotherapy. In this review, we discuss the interaction mechanism between TME and TNBC immunotherapy based on the characteristics and composition of TME, and elaborate on and analyze the effect of TME on immunotherapy, the potential of TME as an immune target, and the ability of TME as a biomarker. Understanding these dynamics will offer new insights for enhancing therapeutic approaches and investigating stratification and prognostic markers for TNBC patients.

Current and future immunotherapy for breast cancer

Substantial therapeutic advancement has been made in the field of immunotherapy in breast cancer. The immune checkpoint inhibitor pembrolizumab in combination with chemotherapy received FDA approval for both PD-L1 positive metastatic and early-stage triple-negative breast cancer, while ongoing clinical trials seek to expand the current treatment landscape for immune checkpoint inhibitors in hormone receptor positive and HER2 positive breast cancer. Antibody drug conjugates are FDA approved for triple negative and HER2+ disease, and are being studied in combination with immune checkpoint inhibitors. Vaccines and bispecific antibodies are areas of active research. Studies of cellular therapies such as tumor infiltrating lymphocytes, chimeric antigen receptor-T cells and T cell receptor engineered cells are promising and ongoing. This review provides an update of recent major clinical trials of immunotherapy in breast cancer and discusses future directions in the treatment of breast cancer.

Identifying subgroups deriving the most benefit from PD-1 checkpoint inhibition plus chemotherapy in advanced metastatic triple-negative breast cancer: a systematic review and meta-analysis

BACKGROUND

The combination of immunotherapy and chemotherapy has demonstrated an enhancement in progression-free survival (PFS) for individuals with advanced and metastatic triple-negative breast cancer (TNBC) when compared to the use of chemotherapy alone. Nevertheless, the extent to which different subgroups of metastatic TNBC patients experience this benefit remains uncertain.

OBJECTIVES

Our objective was to conduct subgroup analyses to more precisely identify the factors influencing these outcomes.

MATERIALS AND METHODS

The PubMed database was searched until Dec 2023 for studies that compared PD-1 checkpoint inhibitors plus chemotherapy (ICT) with chemotherapy (CT) alone. The primary outcome of interest was progression-free survival (PFS). Review Manager (RevMan) version 5.4. was used for the data analysis.

RESULTS

Four randomized controlled trials (RCTs) comprising 2468 advanced and metastatic TNBC were included in this systematic review and meta-analysis. PFS surge with combined therapy was observed in White (HR 0.80 [0.70, 0.91], p = 0.0007) and Asian ethnicities (HR 0.73 [0.58, 0.93], p = 0.01) but not in Blacks (HR 0.72 [0.42, 1.24], p = 0.24). Overall, patients with distant metastasis demonstrated to derive the PFS benefit from additional immunotherapy (HR 0.87 [0.77, 0.99], p = 0.03); however, metastasis to individual distant site was associated with failure to achieve any treatment difference (Bone: HR 0.79 [0.41, 1.52], p = 0.49; Lung: HR 0.85 [0.70, 1.04], p = 0.11; Liver: HR 0.80 [0.64, 1.01], p = 0.06). While number of metastases > 3 also showed to impact the PFS advantage (HR 0.89 [0.69, 1.16], p = 0.39). While patients, regardless of prior chemotherapy, experienced a notable enhancement in PFS with ICT (Overall: HR 0.79 [0.71, 0.88], p < 0.0001; Yes: HR 0.87 [0.76, 1.00], p = 0.05; No: HR 0.67 [0.56, 0.80], p < 0.00001), those previously exposed to chemotherapy exhibited a significantly smaller PFS advantage compared to those without prior chemotherapy, as evidenced by a significant subgroup difference (Test for subgroup difference: P = 0.02, I2 = 82.2%). Patients lacking PD-L1 expression also failed to achieve any additional benefit from immunotherapy (PD-L1-: HR 0.95 [0.81, 1.12]; p = 0.54; PD-L1+: HR 0.73 [0.64, 0.85], p < 0.0001). Age, ECOG status, and presentation with de novo metastasis/recurrent shown no impact on IT-associated PFS advantage.

CONCLUSIONS

Patient- and treatment- related factors such as ethnicity, distant metastases, number of metastases (> 3), previous exposure to chemotherapy and PD-L1 expression, seem to influence or restrict the advantage in progression-free survival associated with the addition of immunotherapy to chemotherapy, as opposed to chemotherapy alone, in patients with advanced and metastatic TNBC. Larger studies are warranted to validate these outcomes.

Immunotherapy for hormone receptor‒positive HER2-negative breast cancer

Additional therapies are needed to improve outcomes in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative breast cancer. Research on the potential role of immunotherapy, particularly programmed cell death protein 1/programmed cell death ligand 1 inhibitors, is rapidly expanding in both the early and metastatic settings with some preliminary evidence suggesting benefit when used as part of combination therapy. Several ongoing phase 3 studies should help define their future role in treating these patients.

Immune and gene-expression profiling in estrogen receptor low and negative early breast cancer

BACKGROUND

The cutoff of <1% positive cells to define estrogen receptor (ER) negativity by immunohistochemistry (IHC) in breast cancer (BC) is debated. We explored the tumor immune microenvironment and gene-expression profile of patients with early-stage HER2-negative ER-low (ER 1%-9%) BC, comparing them to ER-negative (ER <1%) and ER-intermediate (ER 10%-50%) tumors.

METHODS

Among 921 patients with early-stage I-III, ER ≤50%, HER2-negative BCs, tumors were classified as ER-negative (n = 712), ER-low (n = 128), or ER-intermediate (n = 81). Tumor-infiltrating lymphocytes (TILs) were evaluated. CD8+, FOXP3+ cells, and PD-L1 status were assessed by IHC and quantified by digital pathology. We analyzed 776 BC-related genes in 116 samples. All tests were 2-sided at a <.05 significance level.

RESULTS

ER-low and ER-negative tumors exhibited similar median TILs, statistically significantly higher than ER-intermediate tumors. CD8/FOXP3 ratio and PD-L1 positivity rates were comparable between ER-low and ER-negative groups. These groups showed similar enrichment in basal-like intrinsic subtypes and comparable expression of immune-related genes. ER-low and ER-intermediate tumors showed significant transcriptomic differences. High TILs (≥30%) were associated with improved relapse-free survival (RFS) in ER-low (5-year RFS 78.6% vs 66.2%, log-rank P = .033, hazard ratio [HR] 0.37 [95% CI = 0.15 to 0.96]) and ER-negative patients (5-year RFS 85.2% vs 69.8%, log-rank P < .001, HR 0.41 [95% CI = 0.27 to 0.60]).

CONCLUSIONS

ER-low and ER-negative tumors are similar biological and molecular entities, supporting their comparable clinical outcomes and treatment responses, including to immunotherapy. Our findings contribute to the growing evidence calling for a reevaluation of ER-positive BC classification and management, aligning ER-low and ER-negative tumors more closely.

Datopotamab-deruxtecan plus durvalumab in early-stage breast cancer: the sequential multiple assignment randomized I-SPY2.2 phase 2 trial

Sequential adaptive trial designs can help accomplish the goals of personalized medicine, optimizing outcomes and avoiding unnecessary toxicity. Here we describe the results of incorporating a promising antibody-drug conjugate, datopotamab-deruxtecan (Dato-DXd) in combination with programmed cell death-ligand 1 inhibitor, durvalumab, as the first sequence of therapy in the I-SPY2.2 phase 2 neoadjuvant sequential multiple assignment randomization trial for high-risk stage 2/3 breast cancer. The trial includes three blocks of treatment, with initial randomization to different experimental agent(s) (block A), followed by a taxane-based regimen tailored to tumor subtype (block B), followed by doxorubicin-cyclophosphamide (block C). Subtype-specific algorithms based on magnetic resonance imaging volume change and core biopsy guide treatment redirection after each block, including the option of early surgical resection in patients predicted to have a high likelihood of pathologic complete response, which is the primary endpoint assessed when resection occurs. There are two primary efficacy analyses: after block A and across all blocks for six prespecified HER2-negative subtypes (defined by hormone receptor status and/or response-predictive subtypes). In total, 106 patients were treated with Dato-DXd/durvalumab in block A. In the immune-positive subtype, Dato-DXd/durvalumab exceeded the prespecified threshold for success (graduated) after block A; and across all blocks, pathologic complete response rates were equivalent to the rate expected for the standard of care (79%), but 54% achieved that result after Dato-DXd/durvalumab alone (block A) and 92% without doxorubicin-cyclophosphamide (after blocks A + B). The treatment strategy across all blocks graduated in the hormone-negative/immune-negative subtype. No new toxicities were observed. Stomatitis was the most common side effect in block A. No patients receiving block A treatment alone had adrenal insufficiency. Dato-DXd/durvalumab is a promising therapy combination that can eliminate standard chemotherapy in many patients, particularly the immune-positive subtype.ClinicalTrials.gov registration: NCT01042379 .

A Narrative Review of the Clinical, Humanistic, and Economic Value of Pembrolizumab-Based Immunotherapy for the Treatment of Breast and Gynecologic Cancers

Breast and gynecologic cancers are common across the world and are associated with substantial societal and economic burden. Pembrolizumab was among the first immune checkpoint inhibitors targeting programmed cell death protein 1 to be approved for the treatment of patients with triple-negative breast cancer, cervical cancer, and endometrial cancer. Recent clinical trials have established pembrolizumab regimens as a standard of care treatment for these tumor types. Clinical data are further supported by patient-reported outcome, cost-effectiveness, and real-world evidence. Pembrolizumab monotherapy and combination regimens do not negatively influence health-related quality of life and are cost-effective relative to comparators. Ongoing phase 3 studies with pembrolizumab will expand the current understanding of its use in breast and gynecologic cancers. Several of these studies are in patients with early-stage disease with the hope of curing patients. The main objective of this review is to summarize the clinical, humanistic, and economic value of pembrolizumab in these settings and to describe the future challenges for patients, caregivers, clinicians, and payers.