Clinical applications of circulating tumor DNA in monitoring breast cancer drug resistance

The relationship between circulating tumor cells in peripheral blood and clinical characteristics of pediatric neuroblastoma and prognostic evaluation

This study investigates the correlation between circulating tumor cells (CTCs) in peripheral blood and the clinical characteristics and prognosis of advanced pediatric neuroblastoma (NB). We conducted a retrospective analysis of 144 children with advanced NB who underwent comprehensive treatment. Detailed clinical data were collected, and CTCs were detected using a negative enrichment method combined with immunofluorescence technology. Prognostic evaluation criteria and cutoff values for CTCs were established using ROC curve analysis. Univariate and Cox multivariate regression analyses identified independent risk factors impacting prognosis. Patients were categorized into high and low-expression groups based on optimal cutoff values determined with X-tile software. The high expression group had a significantly higher incidence of disease progression (p < 0.001), maximum tumor diameter ≥10 cm (p = 0.004), undifferentiated subtype (p = 0.034), and stage IV disease (p = 0.007) compared to the low expression group. CTCs were notably higher in patients with progression compared to those with mitigation (p < 0.001), in those with maximum tumor diameter ≥10 cm compared to <10 cm (p < 0.001), and in stage IV compared to stage III patients (p = 0.036). The AUC values for maximum tumor diameter, degree of differentiation, and tumor stage were 0.703, 0.669, 0.574, and 0.598, respectively. The detection of CTCs provides significant insights into the clinical characteristics and prognosis of advanced pediatric NB, highlighting its potential as a prognostic tool.

The association of blood ctDNA levels to mutations of marker genes in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is a deadly and commonly diagnosed cancer. Cell-free circulating tumor DNAs (ctDNA) have been used in the diagnosis and treatment of CRC, but there are open questions about the relationship between ctDNAs and CRC. Although mutations of genes detected by ctDNA in CRC have been studied, the quantitative relationship between ctDNA mutations and ctDNA concentration has not been addressed.

AIMS

We hypothesized that there was an association between mutations of genes identified in ctDNAs and ctDNA concentration. His study examined this association in a population of CRC patients.

METHODS

In 85 CRC patients, we sampled 282 mutations in 36 genes and conducted an association study based on a Random forest model between mutations and ctDNA concentrations in all patients.

RESULTS

This association study showed that mutations on five genes, ALK, PMS2, KDR, MAP2K1, and MSH2, were associated with the ctDNA concentrations in CRC patients' blood samples. Because ctDNA mutations correlate with ctDNA level, we can infer the tumor burden or tumor size from ctDNA mutations, as well as the survival time for prognosis.

CONCLUSION

Our findings shed light on the associations between mutations of genes identified in ctDNAs and ctDNA concentration in the blood of CRC patients. This discovery provides information regarding the tumor burden or tumor size based on ctDNA mutations.

Molecular Biomarkers for Contemporary Therapies in Hormone Receptor-Positive Breast Cancer

Systemic treatment of hormone receptor-positive (HR+) breast cancer is undergoing a renaissance, with a number of targeted therapies including CDK4/6, mTOR, and PI3K inhibitors now approved for use in combination with endocrine therapies. The increased use of targeted therapies has changed the natural history of HR+ breast cancers, with the emergence of new escape mechanisms leading to the inevitable progression of disease in patients with advanced cancers. The identification of new predictive and pharmacodynamic biomarkers to current standard-of-care therapies and discovery of new therapies is an evolving and urgent clinical challenge in this setting. While traditional, routinely measured biomarkers such as estrogen receptors (ERs), progesterone receptors (PRs), and human epidermal growth factor receptor 2 (HER2) still represent the best prognostic and predictive biomarkers for HR+ breast cancer, a significant proportion of patients either do not respond to endocrine therapy or develop endocrine resistant disease. Genomic tests have emerged as a useful adjunct prognostication tool and guide the addition of chemotherapy to endocrine therapy. In the treatment-resistant setting, mutational profiling has been used to identify ESR1, PIK3CA, and AKT mutations as predictive molecular biomarkers to newer therapies. Additionally, pharmacodynamic biomarkers are being increasingly used and considered in the metastatic setting. In this review, we summarise the current state-of-the-art therapies; prognostic, predictive, and pharmacodynamic molecular biomarkers; and how these are impacted by emerging therapies for HR+ breast cancer.