Clinical Applications of Circulating Tumor Cells in Pharmacotherapy: Challenges and Perspectives

Circulating Tumor Cells and TWIST Expression in Patients with Metastatic Gastric Cancer: A Preliminary Study

Background and Aims: The clinical significance of circulating tumor cells (CTCs) and TWIST expression in CTCs remains unelucidated in patients with gastric cancer (GC). Here, we evaluated CTCs and TWIST expression in CTCs and explored their correlation with prognosis in patients with metastatic GC. Methods: Peripheral blood samples were prospectively obtained from 31 patients with metastatic GC between September 2017 and December 2018, prior to treatment. CTCs were detected using a centrifugal microfluidic system and CTCs positive for TWIST immunostaining were defined as TWIST (+) CTCs. Results: CTCs and TWIST (+) CTCs were detected in 25 (80.6%) and 24 (77.4%) of the 31 patients, respectively. CTC count in patients with first diagnosis of metastatic cancer tended to be higher than that in those with recurrent metastatic cancer, but TWIST (+) CTC count was not different between the two groups. There was no difference in CTC and TWIST (+) CTC counts according to histopathologic type, peritoneal dissemination, hematogenous metastasis, serum tumor makers, or response to first-line chemotherapy. Patients with CTCs > 7.5/7.5 mL of blood showed shorter overall survival (OS) than those with CTCs ≤ 7.5/7.5 mL of blood (p = 0.049). Additionally, patients with TWIST (+) CTCs > 2.5/7.5 mL of blood tended to show shorter OS than those with TWIST (+) CTCs ≤ 2.5/7.5 mL of blood (p = 0.105). Conclusions: Our study demonstrated that high levels of CTCs and TWIST (+) CTCs were associated with worse OS.

Clinical Significance of TWIST-Positive Circulating Tumor Cells in Patients with Esophageal Squamous Cell Carcinoma

Background/Aims

Unlike other gastrointestinal tract cancers, there are relatively few reports on the clinical significance of circulating tumor cells (CTCs) and TWIST, a marker of epithelial-mesenchymal transition, in patients with esophageal squamous cell carcinoma (ESCC). This study aimed to evaluate the clinical significance of TWIST expression in CTCs in patients with ESCC.

Methods

Peripheral blood samples for CTC analyses were prospectively obtained from 52 patients with ESCC prior to treatment between September 2017 and September 2019. CTCs were detected using a centrifugal microfluidic system based on a fluid-assisted separation technique, and CTCs positive for TWIST on immunostaining were defined as TWIST (+) CTCs.

Results

Of the 52 patients with ESCC, CTCs and TWIST (+) CTCs were detected in 44 patients (84.6%) and 39 patients (75.0%), respectively. The CTC and TWIST (+) CTC counts were significantly higher in patients aged >65 years and those who had a large tumor (>3 cm) than in those aged ≤65 years and those who had a small tumor (≤3 cm), respectively. There were no differences in CTC and TWIST (+) CTC counts according to tumor location, histologic grade, or TNM stage. TWIST (+) CTCs were significantly associated with histologic grade; a proportion of TWIST (+) CTCs ≥0.5 was significantly associated with advanced histologic grade. Other clinicopathologic characteristics such as sex, age, tumor location, tumor size, and TNM stages were not significantly associated with TWIST (+) CTCs.

Conclusions

Our study showed that TWIST (+) CTCs were frequently detected in patients with ESCC, and a high proportion of TWIST (+) CTCs was associated with poor differentiation.

The Role of Circulating Tumor Cells in the Metastatic Cascade: Biology, Technical Challenges, and Clinical Relevance

Metastases and cancer recurrence are the main causes of cancer death. Circulating Tumor Cells (CTCs) and disseminated tumor cells are the drivers of cancer cell dissemination. The assessment of CTCs’ clinical role in early metastasis prediction, diagnosis, and treatment requires more information about their biology, their roles in cancer dormancy, and immune evasion as well as in therapy resistance. Indeed, CTC functional and biochemical phenotypes have been only partially characterized using murine metastasis models and liquid biopsy in human patients. CTC detection, characterization, and enumeration represent a promising tool for tailoring the management of each patient with cancer. The comprehensive understanding of CTCs will provide more opportunities to determine their clinical utility. This review provides much-needed insights into this dynamic field of translational cancer research.

Diagnostic Sensitivity of NLR and PLR in Early Diagnosis of Gastric Cancer

The neutrophil-lymphocyte ratio (NLR) and the platelet-lymphocyte ratio (PLR) are markers of systemic inflammation. However, there is little evidence of the value of inflammation in the early diagnosis of gastric cancer (GC). A total of 2,606 patients diagnosed with GC in the past three years and 3,219 healthy controls over the same period were included in this study. Peripheral blood samples were obtained to analyze the NLR, PLR, carcinoembryonic antigen (CEA), and carbohydrate antigen 19-9 (CA19-9). The optimal cutoff levels for the NLR and PLR were defined by receiver operating characteristic (ROC) curve analysis (NLR = 2.258, PLR = 147.368). The value of different biomarkers for diagnosing GC was compared by the area under the curve (AUC). The NLR and PLR showed diagnostic sensitivity in GC (AUC = 0.715, AUC = 0.707). Using the Bonferroni correction, the NLR and PLR were superior to CEA and CA19-9 in the diagnosis of GC (P < 0.0001). The systemic inflammatory markers were significantly higher in the early stage of GC than tumor markers. After grouping patients and healthy controls by gender, we found that the diagnostic significance of combined NLR and PLR for GC was greater in male patients than in female patients (P < 0.0001). The diagnostic value of the NLR and PLR in GC is higher than that of the traditional tumor markers CEA and CA19-9. Systemic markers of inflammation are more valuable in male than female patients.

Tumor-associated macrophages: role in cancer development and therapeutic implications

BACKGROUND

Tumor-associated macrophages (TAMs) are known to play important roles in the initiation and progression of human cancers, as well as in angiogenesis. TAMs are considered as main components of the tumor microenvironment. Targeting TAMs may serve as a therapeutic strategy for the treatment of cancer. In this review, the signaling pathways, origin, function, polarization and clinical application of TAMs are discussed. The role of TAMs in tumor initiation, progression, angiogenesis, invasion and metastasis are also emphasized. In addition, a variety of clinical and pre-clinical approaches to target TAMs are discussed.

CONCLUSIONS

Clinical therapeutic approaches that show most promise include blocking the extravasation of TAMs along with using TAMs as diagnostic biomarkers for cancer progression. The targeting of TAMs in a variety of clinical settings appears to be a promising strategy for decreasing metastasis formation and for improving patient outcome.

Liquid biopsy of cancer: a multimodal diagnostic tool in clinical oncology

Over the last decades, the concept of precision medicine has dramatically renewed the field of medical oncology; the introduction of patient-tailored therapies has significantly improved all measurable outcomes. Liquid biopsy is a revolutionary technique that is opening previously unexpected perspectives. It consists of the detection and isolation of circulating tumor cells, circulating tumor DNA and exosomes, as a source of genomic and proteomic information in patients with cancer. Many technical hurdles have been resolved thanks to newly developed techniques and next-generation sequencing analyses, allowing a broad application of liquid biopsy in a wide range of settings. Initially correlated to prognosis, liquid biopsy data are now being studied for cancer diagnosis, hopefully including screenings, and most importantly for the prediction of response or resistance to given treatments. In particular, the identification of specific mutations in target genes can aid in therapeutic decisions, both in the appropriateness of treatment and in the advanced identification of secondary resistance, aiming to early diagnose disease progression. Still application is far from reality but ongoing research is leading the way to a new era in oncology. This review summarizes the main techniques and applications of liquid biopsy in cancer.

Non-invasive fetal sex diagnosis in plasma of early weeks pregnants using droplet digital PCR

Background

Fetal sex determination is useful for families at risk of X-linked disorders, such as Duchenne muscular dystrophy, adrenal hypoplasia, hemophilia. At first, this could be obtained through invasive procedures such as amniocentesis and chorionic villus sampling, having a 1% risk of miscarriage. Since the discovery of cell-free fetal DNA (cffDNA) in maternal plasma, noninvasive prenatal testing permits the early diagnosis of fetal sex through analysis of cffDNA. However, the low amount of cffDNA relative to circulating maternal DNA requires highly sensitive molecular techniques in order to perform noninvasive prenatal diagnosis. In this context we employed droplet digital PCR (ddPCR) in order to evaluate the earliest possible fetal sex determination from circulating DNA extracted from plasma of pregnant women at different gestational ages.

Methods

We identified the fetal sex on cffDNA extracted from 29 maternal plasma samples at early gestational ages, several of them not suitable for qPCR determination, using ddPCR designed for SRY gene target.

Results

All maternal plasma samples were determined correctly for SRY gene target using ddPCR even at very early gestational age (prior to 7 weeks).

Conclusions

The ddPCR is a robust, efficient and reliable technology for the earliest possible fetal sex determination from maternal plasma.