Developing blood-based tests is appealing for non-invasive disease diagnosis, especially when biopsy is difficult, costly, and sometimes not even an option. Tumor-derived exosomes have attracted increasing interest in non-invasive cancer diagnosis and monitoring of treatment response. However, the biology and clinical value of exosomes remains largely unknown due in part to current technical challenges in rapid isolation, molecular classification and comprehensive analysis of exosomes. Here we developed a new microfluidic approach to streamline and expedite the exosome analysis pipeline by integrating specific immunoisolation and targeted protein analysis of circulating exosomes. Compared to the conventional methods, our approach enables selective subpopulation isolation and quantitative detection of surface and intravesicular biomarkers directly from a minimally invasive amount of plasma samples (30 μL) within ~100 min with markedly improved detection sensitivity. Using this device, we demonstrated phenotyping of exosome subpopulations by targeting a panel of common exosomal and tumor-specific markers and multiparameter analyses of intravesicular biomarkers in the selected subpopulation. We were able to assess the total expression and phosphorylation levels of IGF-1R in non-small-cell lung cancer patients by probing plasma exosomes as a non-invasive alternative to conventional tissue biopsy. We foresee that the microfluidic exosome analysis platform will form the basis for critically needed infrastructures for advancing the biology and clinical utilization of exosomes.

Significance: Elevated expression of matrix metalloproteinase 1 (MMP1) is associated with a poor prognosis in a wide variety of advancing tumors, and thus MMPs have emerged as attractive targets for therapeutic strategies of metastatic tumors. However, clinical trials using MMP inhibitors in cancer therapy have proved to be disappointing. These studies support the contention that the use of broad-spectrum inhibitors of MMPs is insufficient for clinical benefit, as new compensatory pathways such as continuous production of exosomes derived from the tumor will be unaffected and will enhance the MMP produced by stromal cells. Therefore, a better understanding of the mechanisms used by tumor-derived exosomes in the induction of MMPs would permit the development of successful clinical strategies for novel MMP inhibitors.

Purpose: Addition of carboplatin (Cb) to anthracycline chemotherapy improves pathologic complete response (pCR), and carboplatin plus taxane regimens also yield encouraging pCR rates in triple-negative breast cancer (TNBC). Aim of the NeoSTOP multisite randomized phase II trial was to assess efficacy of anthracycline-free and anthracycline-containing neoadjuvant carboplatin regimens. Patients and Methods: Patients aged ≥18 years with stage I–III TNBC were randomized (1:1) to receive either paclitaxel (P) weekly × 12 plus carboplatin AUC6 every 21 days × 4 followed by doxorubicin/cyclophosphamide (AC) every 14 days × 4 (CbP → AC, arm A), or carboplatin AUC6 + docetaxel (D) every 21 days × 6 (CbD, arm B). Stromal tumor-infiltrating lymphocytes (sTIL) were assessed. Primary endpoint was pCR in breast and axilla. Other endpoints included residual cancer burden (RCB), toxicity, cost, and event-free (EFS) and overall survival (OS). Results: One hundred patients were randomized; arm A (n = 48) or arm B (n = 52). pCR was 54% [95% confidence interval (CI), 40%–69%] in arm A and 54% (95% CI, 40%–68%) in arm B. RCB 0+I rate was 67% in both arms. Median sTIL density was numerically higher in those with pCR compared with those with residual disease (20% vs. 5%; P = 0.25). At median follow-up of 38 months, EFS and OS were similar in the two arms. Grade 3/4 adverse events were more common in arm A compared with arm B, with the most notable differences in neutropenia (60% vs. 8%; P < 0.001) and febrile neutropenia (19% vs. 0%; P < 0.001). There was one treatment-related death (arm A) due to acute leukemia. Mean treatment cost was lower for arm B compared with arm A (P = 0.02). Conclusions: The two-drug CbD regimen yielded pCR, RCB 0+I, and survival rates similar to the four-drug regimen of CbP → AC, but with a more favorable toxicity profile and lower treatment-associated cost.

Exosomes as mediators of platinum resistance in ovarian cancer

Extracellular vesicles (EVs) play a crucial role in intercellular communication, signaling pathways, and disease pathogenesis by transporting biomolecules such as DNA, RNA, proteins, and lipids derived from their cells of origin, and they have demonstrated substantial potential in clinical applications. Their clinical significance underscores the need for sensitive methods to fully harness their diagnostic potential. In this comprehensive review, we explore EV heterogeneity related to biogenesis, structure, content, origin, sample type, and function roles; the use of EVs as disease biomarkers; and the evolving landscape of EV measurement for clinical diagnostics, highlighting the progression from bulk measurement to single vesicle analysis. This review covers emerging technologies such as single-particle tracking microscopy, single-vesicle RNA sequencing, and various nanopore-, nanoplasmonic-, immuno-digital droplet-, microfluidic-, and nanomaterial-based techniques. Unlike traditional bulk analysis methods, these methods contribute uniquely to EV characterization. Techniques like droplet-based single EV-counting enzyme-linked immunosorbent assays (ELISA), proximity-dependent barcoding assays, and surface-enhanced Raman spectroscopy further enhance our ability to precisely identify biomarkers, detect diseases earlier, and significantly improve clinical outcomes. These innovations provide access to intricate molecular details that expand our understanding of EV composition, with profound diagnostic implications. This review also examines key research challenges in the field, including the complexities of sample analysis, technique sensitivity and specificity, the level of detail provided by analytical methods, and practical applications, and we identify directions for future research. This review underscores the value of advanced EV analysis methods, which contribute to deep insights into EV-mediated pathological diversity and enhanced clinical diagnostics.

Triple-negative breast cancer (TNBC) is classically defined by estrogen receptor (ER) and progesterone receptor (PR) immunohistochemistry expression <1% and absence of HER2 amplification/overexpression. HER2-negative breast cancer with low ER/PR expression (1–10%) has a gene expression profile similar to TNBC; however, real-world treatment patterns, chemotherapy response, endocrine therapy benefit, and survival outcomes for the Low-ER group are not well known. 516 patients with stage I-III HER2-negative breast cancer and ER/PR expression ≤10% who were enrolled in a multisite prospective registry between 2011 and 2019 were categorized on the basis of ER/PR expression. TNBC (ER and PR < 1%) and Low-ER (ER and/or PR 1–10%) groups comprised 87.4% (n = 451) and 12.6% (n = 65) of patients, respectively. Demographic, clinical, and treatment characteristics, including prevalence of germline BRCA1/2 mutation, racial and ethnic distribution, and chemotherapy use were not different between TNBC and Low-ER groups. No difference was observed in recurrence-free survival (RFS) and overall survival (OS) between TNBC and Low-ER groups (3-year RFS 82.5% versus 82.4%, respectively, p = 0.728; 3-year OS 88.0% versus 83.4%, respectively, p = 0.632). Among 358 patients receiving neoadjuvant chemotherapy, rates of pathologic complete response were similar for TNBC and Low-ER groups (49.2% vs 51.3%, respectively, p = 0.808). The HER2-negative Low-ER group is often excluded from TNBC clinical trials assessing novel treatments (immunotherapy and antibody-drug conjugates), thus limiting efficacy data for newer effective therapies in this group. Given that HER2-negative Low-ER disease displays clinical characteristics and outcomes similar to TNBC, inclusion of this group in TNBC clinical trials is encouraged.