Circulating tumor biomarkers in early-stage breast cancer: characteristics, detection, and clinical developments

Circulating Tumor Cell Detection for Therapeutic and Prognostic Roles in Breast Cancer

BACKGROUND

Circulating tumor cells (CTCs) are pivotal liquid biopsy (LB) biomarkers for breast cancer (BC), offering non-invasive insights into tumor progression and metastasis. Despite their clinical promise, CTC detection remains technically challenging due to their extreme rarity in peripheral blood.

METHODS

This review systematically evaluates CTC detection methodologies, including immunoaffinity-based approaches and biophysical techniques, which exhibit inherent trade-offs in sensitivity, specificity, and compatibility with downstream analyses. Furthermore, post-isolation molecular characterization methods spanning genomic, transcriptomic, and proteomic analyses are also critically assessed.

KEY FINDINGS

CTC molecular profiling holds significant clinical relevance, enabling early diagnosis, prognostic stratification, and real-time monitoring of therapeutic response. Baseline CTC counts or quantitative/phenotypic changes during treatment inform therapeutic decision-making, predict drug resistance, and correlate with recurrence risk and metastatic progression.

CONCLUSION

Multimodal analysis integrating CTC morphology, surface markers, and molecular alterations advances precision therapy. However, standardization of detection platforms and clinical validation of CTC-guided protocols remain essential.

Current status of cytokine-induced killer cells and combination regimens in breast cancer

Breast cancer remains a significant health challenge worldwide, with substantial efforts aimed at understanding its pathogenesis, biological characteristics, and clinical triggers. Recently, immunotherapy such as the cytokine-induced killer cells combined with other drug therapies has offered new hope for patients with advanced breast cancer. However, the specific pathogenesis of combination regimens involving cytokine-induced killer cells remains elusive. Besides, the combination of immunotherapy with cytokine-induced killer cells might represent a novel breakthrough. This review outlines the current status of cytokine-induced killer cell therapies and their combination strategies, especially the combination of chemotherapy with molecularly targeted treatments, for the management of breast cancer.

Evaluation of the role of circular RNA (circ-FAF1) as a diagnostic biomarker for breast cancer in a cohort of Egyptian breast cancer patients

BACKGROUND

The identification of circulating potential biomarkers may help earlier diagnosis of breast cancer, which is critical for effective treatment and better disease outcomes. We aimed to study the role of circ-FAF1 as a diagnostic biomarker in female breast cancer using peripheral blood samples of these patients, and to investigate the relation between circ-FAF1 and different clinicopathological features of the included patients.

METHODS AND RESULTS

This case-control study enrolled 60 female breast cancer patients and 60 age-matched healthy control subjects. For all study subjects, serum samples were collected for RNA extraction followed by reverse transcription and quantitative real time polymerase chain reaction for circ-FAF1 relative expression level. Serum circ-FAF1 was significantly downregulated in the studied patients compared to control subjects (p < 0.001). Low expression level of circ-FAF1 was significantly associated with presence of lymph node spread (p < 0.001), positive metastasis (p = 0.002), estrogen receptor negativity (p < 0.001), HER2 positivity (p < 0.001), and it was moderately correlated with higher Ki-67 index (r=-0.429, p = 0.001). However, circulating circ-FAF1 level had no statistically significant correlation with progesterone receptor status (p = 0.053), tumor histopathological type (p = 0.895) and histological grade (p = 0.369). Using ROC curve, serum circ-FAF1 had an AUC of 0.885, 81.67% diagnostic sensitivity and 76.67% diagnostic specificity.

CONCLUSION

Serum level of circ-FAF1 is a promising biomarker that can help in diagnosis of breast cancer. The low expression in breast cancer was correlated with lymph node spread, presence of metastasis, and with histopathological parameters suggestive of a worse outcome in these patients.

Potential role of circulating tumor cells and cell-free DNA as biomarkers in oral squamous cell carcinoma: A prospective single-center study

Metastasis in patients with oral squamous cell carcinoma has been associated with a poor prognosis. However, sensitive and reliable tests for monitoring their occurrence are unavailable, with the exception of PET-CT. Circulating tumor cells and cell-free DNA have emerged as promising biomarkers for determining treatment efficacy and as prognostic predictors in solid tumors such as breast cancer and colorectal cancer. Hence, this study aimed to determine the potential role of liquid biopsy, circulating tumor cells, and cell-free DNA as biomarkers of oral squamous cell carcinoma. Thirteen patients with primary oral squamous cell carcinoma who visited our hospital between 2022 and 2023 were recruited, and plasma samples were collected from each patient preoperatively and postoperatively. We examined the relationship between the prognosis, the number of circulating tumor cells per four milliliters of peripheral blood, and the amount of cell-free DNA per milliliter of serum or the gene mutation in cell-free DNA. We observed no correlation between the number of preoperative circulating tumor cells and metastatic events. However, the number of circulating tumor cell clusters or the amount of preoperative cell-free DNA in metastatic cases was higher than that in non-metastatic cases. In oral squamous cell carcinoma, circulating tumor cell clusters or cell-free DNA levels may help inform management decisions regarding metastasis. However, further studies are required to provide a possible window for therapeutic interventions.

Small intestinal metastasis from primary breast cancer: a case report and review of literature

Small intestinal metastasis from primary breast cancer remains a rare clinical occurrence. Despite extensive research into its clinicopathological features and treatment options, the specific pathogenesis and optimal management strategies remain incompletely understood. This case report presents a patient with breast cancer that metastasized to the small intestine. The primary breast tumor was diagnosed as classic invasive lobular carcinoma. Subsequent surgical intervention successfully addressed the intestinal obstruction and confirmed the metastatic origin of the small intestinal tumor. Interestingly, the metastatic lesions exhibited features suggestive of pleomorphic lobular carcinoma. A PET-CT scan was performed to evaluate the distant metastasis status of this patient. Notably, hormonal receptor status shifted from positive to negative, while HER2 expression changed from negative to low between the primary tumor and metastatic lesions. The presence of an undiagnosed pleomorphic component in the primary tumor might explain the disease's progressive nature. In this case, systemic treatment with trastuzumab deruxtecan yielded favorable therapeutic outcomes. Overall, our findings suggest that re-evaluation of receptor status in breast cancer metastases is crucial for tailoring treatment strategies. Furthermore, a combination of palliative resection of small intestinal metastases and targeted therapy for HER2-low breast cancer may potentially improve survival.

Untargeted metabolomic profiling of small extracellular vesicles reveals potential new biomarkers for triple negative breast cancer

INTRODUCTION

Breast Cancer (BC) is one of the most diagnosed malignancies among women and the second leading cause of cancer related death in North America. Triple Negative BC (TNBC), one of the most severe subtypes of BC, is extremely aggressive and has a higher chance of occurrence in women under 50 years of age. Due to a lack of regular mammographic testing in women under 50, many individuals with TNBC are diagnosed late which can decrease their survival rate. Currently, liquid biopsy is being investigated as a potentially less-invasive alternative to traditional breast tissue biopsy, but this approach is not completely reliable. Blood contains extracellular vesicles (EVs), which carry biomolecular cargo and play a role in BC progression and metastasis. Examination of small EVs could potentially yield metabolite biomarkers for early BC diagnosis.

OBJECTIVE

We aim to study metabolites in small EVs to find biomarkers for BC diagnosis.

METHODS

In this work, an untargeted nano-LC MS/MS metabolomics approach was used to analyze metabolites from small EVs derived from metastatic MDA-MB-231 and compare it with a non-cancerous MCF10A cell line.

RESULTS

Two metabolites, LysoPC 22:6/0:0 and N-acetyl-L-Phenylalanine, unique to sEVs of MDA-MB-231, were identified, validated, and proposed as potential BC biomarkers.

CONCLUSION

Metabolites from sEVs may be used for BC diagnosis.

Leveraging the intratumoral microbiota to treat human cancer: are engineered exosomes an effective strategy?

Cancer remains a leading cause of global mortality. The tumor microbiota has increasingly been recognized as a key regulator of cancer onset and progression, in addition to shaping tumor responses to immunotherapy. Microbes, including viruses, bacteria, fungi, and other eukaryotic species can impact the internal homeostasis and health of humans. Research focused on the gut microflora and the intratumoral microbiome has revolutionized the current understanding of how tumors grow, progress, and resist therapeutic interventions. Even with this research, however, there remains relatively little that is known with respect to the abundance of microbes and their effects on tumors and the tumor microenvironment. Engineered exosomes are a class of artificial extracellular nanovesicles that can actively transport small molecule drugs and nucleic acids, which have the broad prospects of tumor cell therapy. The present review offers an overview of recent progress and challenges associated with the intratumoral microbiome and engineered exosomes in the context of cancer research. These discussions are used to inform the construction of a novel framework for engineered exosome-mediated targeted drug delivery, taking advantage of intratumoral microbiota diversity as a strategic asset and thereby providing new opportunities to more effectively treat and manage cancer in the clinic.