Real-time quantitative RT-PCR detection of disseminated endometrial tumor cells in peripheral blood and lymph nodes using the LightCycler System

Circulating Tumor Cell Detection by Liquid Biopsy during Early-Stage Endometrial Cancer Surgery: A Pilot Study

The recurrence of non-metastatic endometrial carcinoma (EC) (6 to 21%) might be due to disseminated tumor cells. This feasibility study investigated whether circulating tumor cells (CTCs) were detectable in blood samples from the peripheral and ovarian veins of 10 patients undergoing laparoscopic resection of stage I-II EC between July 2019 and September 2021. CTCs were detected using the CellSearch® system (i) preoperatively (T0) in peripheral blood, (ii) after ovary suspensory ligament pediculation in ovarian vein blood (T1), and (iii) before colpotomy in peripheral blood (T2). CTCs were detected only in ovarian vein samples in 8/10 patients. The CTC median number did not differ with patient age (37 (min-max: 0–91) in <70-year-old vs. 11 (0–65) in ≥70 year-old women, p = 0.59), tumor grade (15 (0–72) for grade 1 vs. 15 (0–91) for grade 2, p = 0.97), FIGO stage (72 (27–91) vs. 2 (0–65) vs. 3 (0–6]) for stage IA, B, and II, respectively; p = 0.08), and tumor size (40 (2–72) for size < 30 mm vs. 4 (0–91) for size ≥ 30 mm, p = 0.39). Estrogen receptor-positive CTCs and CTC clusters were identified. The prognostic and therapeutic values of CTCs released during EC surgery need to be determined.

Circulating tumor cells and cell-free nucleic acids in patients with gynecological malignancies

The ability to detect cancer cells in the blood or in the bone marrow offers invaluable information which potentially impacts early diagnosis, monitoring of treatment, and prognosis. Accessing blood or other body fluids has the additional advantage of being less invasive than biopsy. Consequently, considerable effort has been invested in the last 20 years in optimizing assays which may identify malignant cells at these anatomic sites. Detection of nucleic acids has been applied as alternative approach in this context, first targeting single cancer-associated genes using PCR-based technology, and recently using assays which identify different DNA classes, as well as microRNAs and exosomes. The present review focuses on studies which applied these assays to the detection of cells or cellular components originating from gynecological cancers.

A new diagnostic method for rapid detection of lymph node metastases using a one-step nucleic acid amplification (OSNA) assay in endometrial cancer

BACKGROUND

To improve lymph node (LN) metastasis identification for patients with endometrial cancer (EC), this study assessed the usefulness of molecular biologic techniques using a one-step nucleic acid amplification (OSNA) assay.

METHODS

Using quantitative reverse transcription polymerase chain reaction (qRT-PCR), an optimal mRNA marker was selected, and its expression was compared between histopathologically positive and negative LNs using an OSNA assay. The authors determined copy number cutoff values and evaluated the diagnostic performance of this OSNA assay using sentinel lymph nodes (SLNs). They also investigated whether an OSNA assay could detect LN metastases with sensitivity and specificity equivalent to the 2-mm-interval histopathology method.

RESULTS

For analysis of EC samples, cytokeratin 19 (CK19) was selected as a useful mRNA marker for the OSNA assay. When the cutoff value was set at 250 copies (using 215 LNs from 70 patients), an OSNA assay using CK19 mRNA had a sensitivity of 93.3%, a specificity of 99.5%, and a concordance rate of 99.1%. For performance evaluations using SLNs (120 histopathologically negative LNs and 17 histopathologically positive LNs from 35 patients), a OSNA assay using CK19 mRNA had a sensitivity of 82.4%, a specificity of 99.2%, a positive predictive value of 93.3%, and a concordance rate of 97.1%. Thus, an OSNA assay using CK19 mRNA provided results equivalent to those with the 2-mm-interval histopathology method.

CONCLUSIONS

The study data demonstrated that an OSNA assay using CK19 mRNA was applicable for detecting LN metastases in EC. Combined analysis using an OSNA assay and SLNs may improve individualized treatments according to LN metastatic status.

[Advances in research on circulating tumor cells in lung cancer]

转移和复发是肺癌患者死亡的主要原因。研究发现循环肿瘤细胞（circulating tumor cells, CTCs）在肺癌转移和复发中起着重要作用。而且随着靶向治疗的不断进步，对于晚期无法取得肺癌实体组织的患者，CTCs作为一种肺癌组织替代物可以决定治疗方案。所以CTCs在早期发现肺癌患者的微转移、检测肿瘤复发、评估预后和选择个体化治疗方案方面有着重要作用。本文针对CTCs的研究进展及肺癌领域的应用进行综述。

Assessment of a six gene panel for the molecular detection of circulating tumor cells in the blood of female cancer patients

Background

The presence of circulating tumor cells (CTC) in the peripheral blood of cancer patients has been described for various solid tumors and their clinical relevance has been shown. CTC detection based on the analysis of epithelial antigens might be hampered by the genetic heterogeneity of the primary tumor and loss of epithelial antigens. Therefore, we aimed to identify new gene markers for the PCR-based detection of CTC in female cancer patients.

Methods

Gene expression of 38 cancer cell lines (breast, ovarian, cervical and endometrial) and of 10 peripheral blood mononuclear cell (PBMC) samples from healthy female donors was measured using microarray technology (Applied Biosystems). Differentially expressed genes were identified using the maxT test and the 50% one-sided trimmed maxT-test. Confirmatory RT-qPCR was performed for 380 gene targets using the AB TaqMan^® Low Density Arrays. Then, 93 gene targets were analyzed using the same RT-qPCR platform in tumor tissues of 126 patients with primary breast, ovarian or endometrial cancer. Finally, blood samples from 26 healthy women and from 125 patients (primary breast, ovarian, cervical, or endometrial cancer, and advanced breast cancer) were analyzed following OncoQuick enrichment and RNA pre-amplification. Likewise, hMAM and EpCAM gene expression was analyzed in the blood of breast and ovarian cancer patients. For each gene, a cut-off threshold value was set at three standard deviations from the mean expression level of the healthy controls to identify potential markers for CTC detection.

Results

Six genes were over-expressed in blood samples from 81% of patients with advanced and 29% of patients with primary breast cancer. EpCAM gene expression was detected in 19% and 5% of patients, respectively, whereas hMAM gene expression was observed in the advanced group (39%) only. Multimarker analysis using the new six gene panel positively identified 44% of the cervical, 64% of the endometrial and 19% of the ovarian cancer patients.

Conclusions

The panel of six genes was found superior to EpCAM and hMAM for the detection of circulating tumor cells in the blood of breast cancer, and they may serve as potential markers for CTC derived from endometrial, cervical, and ovarian cancers.

Advances in research on circulating tumor cells

Circulating tumor cells (CTCs) are defined as cells that have detached, spontaneously or as a result of clinical operations, from a primary tumor or its metastatic lesions and circulate in the peripheral blood. They are considered as the primary reason for postoperative recurrence and distant metastasis of malignant tumors. In recent years, non-invasive detection of circulating tumor cells has become a new type of diagnostic tool to evaluate postoperative recurrence, distant metastasis, and prognosis. This article reviews recent advances in research on circulating tumor cells.

Detection of disseminated tumour cells in mediastinoscopic lymph node biopsies and endobronchial ultrasonography-guided transbronchial needle aspiration in patients with suspected lung cancer

PURPOSE

Ultrasound-guided transbronchial needle aspiration of mediastinal lymph nodes (EBUS-TBNA) is apparently more accurate for cancer diagnosis than standard transbronchial needle aspiration (TBNA), but it is less sensitive than mediastinoscopy. The detection of disseminated tumour cells in transbronchial needle aspiration and mediastinoscopic biopsies could improve staging and might be helpful concerning indications for neoadjuvant regimen. The goal of this study was to develop a quantitative method for the detection of disseminated tumour cells (DTCs) in lymph node samples from patients with suspected lung cancer.

PATIENTS AND METHODS

We compared in a prospective trail EBUS-TBNA (n=58 patients, 86 samples) and mediastinoscopy (n=22 patients, 37 samples) in two largely independent cohorts of lung cancer patients. Eleven patients, 14 samples were analysed using both methods. Patients without evidence of malignant disease were available as controls for EBUS-TBNA (n=20 patients, 28 samples) and mediastinoscopy (n=6 patients, 8 samples). Real-time quantitative mRNA analysis was performed for the cytokeratin 19 (CK19) and MAGE-A genes (MAGE-A 1-6, MAGE-A12) as markers, using a LightCycler 480 instrument.

RESULTS

CK19 mRNA expression in EBUS-TBNA samples was detected in 84/86 (98%) and in 28/28 control samples (100%). After mediastinoscopy 16/37 (43%) samples of lung cancer patients were CK19 mRNA positive while controls showed no CK19 mRNA expression (0/8). MAGE-A expression was detectable in 42/86 (49%) EBUS-TBNA samples and in 13/37 (35%) mediastinoscopy samples. MAGE-A expression was detected in EBUS-TBNA controls in 3/28 (11%) and 1/8 (12%) mediastinoscopy controls. High MAGE-A expression correlated with increased tumour stage.

CONCLUSION

Since CK19 expression was detected in all EBUS-TBNA samples from the control patients, but not in mediastinoscopy samples, we conclude that CK19 is not suitable as a marker for disseminated tumour cells in samples attained by EBUS-TBNA. One possible explanation is a contamination with epithelial cells from the bronchial tubes. MAGE-A genes are promising markers for disseminated tumour cells in lymph nodes in patients with suspected lung cancer which merit further investigation.

Flow cytometric analysis of CK19 expression in the peripheral blood of breast carcinoma patients: relevance for circulating tumor cell detection

Background

Immunocytochemistry and RT-PCR have been widely used for the detection of circulating tumor cells in patients with breast cancer but their specificity is limited. Our purpose is to utilize a convenient and specific technology to detect circulating tumor cells in breast cancer patients.

Methods

To determine the sensitivity and specificity of our method, A431 cells were serially diluted with human peripheral blood leukocytes and stained with CK19. A total of 73 blood specimens including 25 healthy volunteers and 48 patients with breast carcinoma and benign tumor were tested by flow cytometry to quantify the expression of CK19.

Results

The detectable upper limit of A431 cells was 1 cancer cell among 10⁴ human white blood cells. CK19 was detected in 27% of breast cancer patients but none control gives positive result. The number of cancer cells increased gradually along with the disease stages for it was the least in stage I (0%) and the most in stage IV (1.29%). Fifteen patients were observed during three month chemotherapy after surgery, and most of their CK19 expression levels declined after treatment.

Conclusion

Our research convinces that the detection of CK19 in peripheral blood by flow cytometry is also a specific and feasible method to monitor circulating tumor cells in breast cancer.

Towards an optimized platform for the detection, enrichment, and semi-quantitation circulating tumor cells

Metastasis describes the process of migration of a frequently clinically occult circulating tumor cell (CTC) from the primary lesion to a new location and the subsequent formation of an overt growth. We and others have shown that the detection and quantitation of these cells has significant prognostic value, however there still remains no consensus as to the optimal methods to achieve this. The work described herein therefore considered various techniques, from storage and sample processing to data acquisition and analysis, to find an optimal combination of methods for an effective and practical platform for the detection of CTCs in peripheral blood. A dual-antigen epithelial cell enrichment procedure followed by a multi-marker QPCR analysis demonstrated the highest sensitivity and specificity, with the ability to detect as few as 10 tumor cells from a background of 10(6) peripheral blood mononuclear cells. Using these techniques in conjunction with a quadratic linear discriminant analysis (QDA) resulted in a platform able to generate this data and then combine it a single score for each patient, in which positivity reflected tumor cell presence, and negativity represented tumor cell absence. This assay was able to correctly determine tumor cell presence or absence in 100% of healthy controls and 84% of metastatic patients in a validation cohort of 39 individuals. This platform represents a highly sensitive and specific assay which could augment current routine assays for CTCs in the clinic.

Dopamine agonist cabergoline reduces hemoconcentration and ascites in hyperstimulated women undergoing assisted reproduction

CONTEXT

Ovarian hyperstimulation syndrome (OHSS) results from increased vascular permeability (VP) caused by ovarian hypersecretion of vascular endothelial growth factor (VEGF), which activates its receptor-2. In animals, the dopamine receptor 2 agonist cabergoline (Cb2) inactivates VEGF receptor-2 and prevents increased VP.

OBJECTIVE

Our objective was to test whether Cb2 reduces VP and prevents OHSS in humans.

DESIGN

We conducted a prospective, randomized, double-blind study on oocyte donors at risk of developing OHSS (>20 follicles, >12 mm developed, and >20 oocytes retrieved).

INTERVENTIONS

Cb2 0.5 mg/d (n = 37) or a placebo (n = 32) was administered from the day of human chorionic gonadotropin (d 0) until d 8. Ascites (a pocket of peritoneal fluid > 9 cm(2) in lithotomy position), hemoconcentration, and serum prolactin were recorded. Pharmacokinetic studies with magnetic resonance employing the transfer constant rate (K(trans), measure of permeability) and the extravascular extracellular space (upsilon(e), marker of cellular leakage) were performed to measure VP objectively.

RESULTS

Hematocrit (P < 0.01), hemoglobin (P = 0.003), and ascites (P = 0.005) were significantly lower on d 4 and 6 after treatment with Cb2 as compared with placebo. The incidence of moderate OHSS was 20.0 and 43.8%, respectively (P = 0.04). Magnetic resonance studies showed an increase in VP and extravascular leakage of fluid 5 d after human chorionic gonadotropin injection that was significantly prevented with Cb2 (K(trans) P = 0.04 and upsilon(e) P = 0.001, respectively).

CONCLUSIONS

Given that Cb2 is a well-established and safe medication, this study provides proof of concept for the use of dopamine agonists in the prevention of OHSS in women undergoing assisted reproduction.

Detection of disseminated tumor cells in patients with gynecological cancers

OBJECTIVES

The presence of disseminated tumor cells (DTC) in breast cancer patients is associated with poor prognosis. However, there are limited data about the prevalence and prognostic impact of DTC in patients with gynecological tumors. The aim of this study was to evaluate the presence of DTC in the bone marrow (BM) of patients with gynecological cancers and to correlate their presence with established prognostic factors.

METHODS

BM aspirates of 201 patients with primary ovarian (n=69), cervical (n=54) and endometrial cancer (n=78), undergoing surgery at the Department of Gynecology and Obstetrics, University Hospital, Tuebingen, Germany between 1/2002 and 01/2006, were included into the study. Cytokeratin (CK)-positive cells were identified by immunocytochemistry using the pancytokeratin antibody A45B/B3.

RESULTS

The bone marrow positivity rate was 36% in ovarian, 26% in cervical and 17% in endometrial cancer, respectively. Presence of DTC was significantly correlated with FIGO (International Federation of Gynecology and Obstetrics) tumor stage (p<0.05). The recurrence rate was 14% in patients with CK-positive cells compared to 8% in CK-negative patients (p=0.2). There was no correlation between DTC and other established prognostic factors including nodal status or grading except for cervical cancer. Patients with positive lymph node status were more likely to be bone marrow positive compared to those with negative lymph node status (p<0.05).

CONCLUSIONS

Disseminated tumor cells seem to be a general phenomenon in epithelial tumors even though their clinical impact remains to be evaluated. The hypothesis that bone marrow is the homing site of disseminated tumor cells is further supported by these data since gynecological tumors only rarely metastasize to the skeletal system.