Association of Circulating Tumor Cells and Tumor Molecular Profile With Clinical Outcomes in Patients With Previously Untreated Metastatic Colorectal Cancer: A Pooled Analysis of the Phase III VISNÚ-1 and Phase II VISNÚ-2 Randomized Trials

Associations of blood RNA biomarkers and circulating tumour cells in patients with previously untreated metastatic colorectal cancer

BACKGROUND

In patients with metastatic colorectal cancer, analysis of the number of basal circulating tumour cells (bCTCs) has been shown to be a strong prognostic indicator. In this study, we aim to explore the potential associations between whole blood mRNA and microRNA expression profiles and bCTC counts, tumour mutations and prognosis in untreated metastatic colorectal cancer patients.

METHODS

A total of 151 patients previously screened for inclusion in two clinical trials (VISNÚ1 and VISNÚ2) were enrolled in this study. Real-time quantitative PCR (qPCR) analyses were performed to determine the whole blood expression of selected RNAs (mRNAs and microRNAs) involved in the metastatic process. The CellSearch system was used to enumerate circulating tumour cells. The primary objective was to correlate RNA expression with the number of bCTCs, while the secondary objectives were to investigate the relationship between the levels of circulating RNA biomarkers in whole blood and the clinical, pathological, and molecular characteristics and prognosis of patients with metastatic colorectal cancer.

RESULTS

bCTC count was significantly associated with AGR2 mRNA in the entire cohort of 151 patients. AGR2, ADAR1 and LGR5 were associated with the number of bCTC, both in the subgroup with bCTC ≥ 3 and in the subgroup with native RAS/BRAF/PIK3 CA tumours. In patients with RAS/BRAF/PIK3 CA mutations no correlations with bCTC were detected, but an upregulation of miR-224-5p and the stemness marker LGR5 and a downregulation of immune regulatory CD274 were found. Lower levels of miR-106a-5p/miR-26a-5p were associated with shorter overall survival, with independent statistical significance in the multivariate analysis.

CONCLUSIONS

A correlation was identified between the levels of a subset of whole blood RNAs, including AGR2, ADAR1, and LGR5, and the number of bCTC and RAS/BRAF/PIK3 CA mutational status. Furthermore, another set of whole blood RNAs, specifically miR-106a-5p and miR-26a-5p, was found to be associated with poor prognosis. This may be helpful for risk stratification.

TRIAL REGISTRATION

Clinical Trials Gov. NCT01640405 and NCT01640444. Registered on 13 June 2012. https://clinicaltrials.gov/ .

Circulating tumor cells in solid malignancies: From advanced isolation technologies to biological understanding and clinical relevance in early diagnosis and prognosis

Circulating tumor cells (CTCs) are shed from primary tumors and travel through the body via circulation, eventually settling to form micrometastases under favorable conditions. Numerous studies have identified CTCs as a negative prognostic indicator for survival across various cancer types. CTCs mirror the current heterogeneity and genetic and biological state of tumors, making their study invaluable for understanding tumor progression, cell senescence, and cancer dormancy. However, their isolation and characterization still poses a major challenge that limits their clinical translation. A wide array of methods, each with different levels of specificity, utility, cost, and sensitivity, have been developed to isolate and characterize CTCs. Moreover, innovative techniques are emerging to address the limitations of existing methods. In this review, we provide insights into CTC biology addressing spectra of markers employed for molecular analysis and functional characterization. It also emphasizes current label-dependent and label-independent isolation procedures, addressing their strengths and limitations. SIGNIFICANCE: A comprehensive overview of CTC biology, their molecular and functional characterization, along with their current clinical utility will help in understanding the present-day extent to which the clinical potential of CTCs is getting tapped in personalized medicine.

The correlation study between TOP2A gene expression in circulating tumor cells and chemotherapeutic drug resistance of patients with breast cancer

BACKGROUND

Patients with breast cancer (BC) at advanced stages have poor outcomes because of high rate of recurrence and metastasis. Biomarkers for predicting prognosis remain to be explored. This study aimed to evaluate the relationships between circulating tumor cells (CTCs) and outcomes of BC patients.

PATIENTS AND METHODS

A total of 50 female were enrolled in this study. Their diagnoses were determined by clinical characteristics, image data, and clinical pathology. CTC subtypes and TOP2A gene expression on CTCs were detected by CanPatrol™ technology and triple color in situ RNA hybridization (RNA-ISH), which divided into epithelial CTCs (eCTCs), mesenchymal CTCs (MCTCs), and hybrid CTCs (HCTCs) based on their surface markers. Hormone receptor, including estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2) expression, was measured by immunohistochemistry (IHC) method before treatment. The risk factors for predicting recurrence and metastasis were calculated by COX risk regression model. The progression-free survival (PFS) of patients was determined using Kaplan-Meier survival curve.

RESULTS

The patients with a large tumor size (≥ 3 cm) and advanced tumor node metastasis (TNM) stages had high total CTCs (TCTCs) (P < 0.05). These patients also had high TOP2A expression level. COX risk regression analysis indicated that TOP2A expression levels in TCTCs, ER + , HER-2 + , and TNM stages were critical risk factors for recurrence and metastasis of patients (P < 0.05). The PFS of patients with ≥ 5 TCTCs, ≥ 3 HCTCs, and positive TOP2A expression in ≥ 3 TCTCs was significantly longer than that in patient with < 5 TCTCs, < 3 HCTCs, and TOP2A expression in < 3 TCTCs (P < 0.05). In contrast, the PFS of patients with positive hormone receptors (ER + , PR + , HER-2 +) also was dramatically lived longer than that in patients with negative hormone receptor expression.

CONCLUSIONS

High TCTC, HCTCs, and positive TOP2A gene expression on CTCs were critical biomarkers for predicting outcomes of BC patients. Positive hormone receptor expression in BC patients has significant favor PFS.

Circulating Tumor Cells: How Far Have We Come with Mining These Seeds of Metastasis?

Circulating tumor cells (CTCs) are cancer cells that slough off from the tumor and circulate in the peripheral blood and lymphatic system as micro metastases that eventually results in macro metastases. Through a simple blood draw, sensitive CTC detection from clinical samples has proven to be a useful tool for determining the prognosis of cancer. Recent technological developments now make it possible to detect CTCs reliably and repeatedly from a simple and straightforward blood test. Multicenter trials to assess the clinical value of CTCs have demonstrated the prognostic value of these cancer cells. Studies on CTCs have filled huge knowledge gap in understanding the process of metastasis since their identification in the late 19th century. However, these rare cancer cells have not been regularly used to tailor precision medicine and or identify novel druggable targets. In this review, we have attempted to summarize the milestones of CTC-based research from the time of identification to molecular characterization. Additionally, the need for a paradigm shift in dissecting these seeds of metastasis and the possible future avenues to improve CTC-based discoveries are also discussed.