The clinical usefulness of the intraoperative detection of sentinel lymph node metastases by a rapid RT-PCR system in patients with gastric cancer

A thirty-three gene-based signature predicts lymph node metastasis and prognosis in patients with gastric cancer

Recently, several studies have indicated the great potential of gene expression signature of the primary tumor in predicting lymph node metastasis; however, few current gene biomarkers can predict lymph node status and prognosis in gastric cancer (GC). Thus, we used the RNA-seq data from The Cancer Genome Atlas (TCGA) to identify differentially expressed genes between pathological lymph node-negative (pN0) and positive (pN+) patients and to establish a gene signature that could predict lymph node metastasis. Meanwhile, the robustness of identified gene signatures was validated in an independent dataset Asian Cancer Research Group (n = 300). In this study, our thirty-three gene-based signature was highly correlated with lymph node metastasis and could successfully discriminate pN + patients in the training set (Area under the receiver operating characteristic curve = 0.951). Moreover, Disease-free survival (P = 0.0029) and overall survival (P = 0.026) were significantly worse in high-risk compared with low-risk patients overall and when confined to pN0 patients only (P < 0.0001). Of note, this gene signature also proved useful in predicting lymph node status and survival in the validation cohort. The present study suggests a thirty-three gene-based signature that could effectively predict lymph node metastasis and prognosis in GC.

Mapping Lymph Node during Indocyanine Green Fluorescence-Imaging Guided Gastric Oncologic Surgery: Current Applications and Future Directions

Huge strides have been made in the navigation of gastric cancer surgery thanks to the improvement of intraoperative techniques. For now, the use of indocyanine green (ICG) enhanced fluorescence imaging has received promising results in detecting sentinel lymph nodes (SLNs) and tracing lymphatic drainages, which make it applicable for limited and precise lymphadenectomy. Nevertheless, issues of the lack of specificity and unpredictable false-negative lymph nodes were encountered in gastric oncologic surgery practice using ICG-enhanced fluorescence imaging (ICG-FI), which restrict its application. Here, we reviewed the current application of ICG-FI and assessed potential approaches to improving ICG-FI.

A preliminary study on the detection of lymph node metastasis in cervical cancer using a quantitative RT-PCR assay

OBJECTIVE

This preliminary study aimed to assess the detection accuracy of sentinel lymph node metastasis in cervical cancer using quantitative reverse transcriptase-polymerase chain reaction.

METHODS

We collected cervical cancer tissues and 70 pelvic lymph node samples from patients with cervical cancer. The quantitative reverse transcriptase-polymerase chain reaction assay was performed to investigate the expression of cytokeratin 19 mRNA in cervical cancer tissues and determine the cutoff value of cytokeratin 19 mRNA between the non-metastatic and metastatic lymph nodes.

RESULTS

The expression of cytokeratin 19 mRNA in cancer tissues was detected in all (71/71) the tumours, with a median copy number of 7.56 × 105/μl of RNA by quantitative reverse transcriptase-polymerase chain reaction. Sixteen lymph nodes were diagnosed as positive by pathological examination. The median copy numbers of cytokeratin 19 mRNA for positive and negative lymph nodes were 43.3 × 104/μl and 121.1/μl, respectively. The expression of cytokeratin 19 mRNA in pathologically positive lymph nodes was higher than that in the negative lymph nodes (P < 0.0001) by quantitative reverse transcriptase-polymerase chain reaction analysis. Using a receiver operating characteristic plot, the maximum sensitivity (100%) and specificity (94.4%) were obtained when the cutoff value was set at 1169 copies/μl.

CONCLUSIONS

After setting the cutoff value at 1169 copies/μl, a quantitative reverse transcriptase-polymerase chain reaction assay using cytokeratin 19 mRNA showed high accuracy in detecting lymph node metastasis in cervical cancer. We believe that the quantitative reverse transcriptase-polymerase chain reaction assay using cytokeratin 19 mRNA may be acceptable for lymph node metastasis detection in patients with cervical cancer.

Quantitative RT-PCR Assay for Detecting Lymph Node Metastasis in Endometrial Cancer: A Preliminary Study

OBJECTIVE

The detection accuracy of sentinel lymph node (SLN) metastasis by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) for endometrial cancer (EC) remains unclear and was assessed in this preliminary study.

METHODS

We studied primary cancer tissues and pelvic lymph nodes (PLN) from 105 patients with EC. qRT-PCR assay was performed to determine the copy numbers of CK19 mRNA in EC tissues, and negative and positive LN samples. Further, qRT-PCR results were compared with pathological findings.

RESULTS

CK19 mRNA expression was detected in 98% (104/106) of the tumors, with a median copy number of 3.0 × 105/μL. Twelve LN were diagnosed as positive by pathological examination. The median copy number of CK19 mRNA for positive and negative LN was 8.1 × 104/μL and 90.4/µL, respectively. CK19 mRNA expression was higher in pathologically positive LN than in pathologically negative LN (p < 0.01); the pathological and qRT-PCR findings showed no discrepancy. When the cutoff value was set at 4,500 copies/µL, qRT-PCR assay using CK19 mRNA exhibited high sensitivity and specificity.

CONCLUSIONS

Our results demonstrated that qRT-PCR assay, using CK19 mRNA, exhibits a high accuracy for detecting LN metastasis in EC and represents a useful alternative to conventional pathological diagnosis of EC.

Quantitative assessment of fluorescence intensity of ICG in sentinel nodes in early gastric cancer

BACKGROUND

The sentinel node (SN) detection by dual tracer method using indocyanine green (ICG) and a radioisotope (RI) has been recommended for early gastric cancer. However, institutions are limited due to radioactivity in the RI method. The greatest advantage of the RI method is that it objectively assesses RI uptake as a numerical value. The aim of the present study was to verify the usefulness of ICG fluorescence intensity in SN.

METHODS

Seventeen patients with early gastric cancer were enrolled in this study. RI uptake by each lymph node was measured using Navigator GPS and fluorescence nodes were identified using the hyper eye medical system (HEMS). Fluorescence intensity in fluorescence nodes was evaluated using ICG intensity imaging software (Mizuho, Japan) of the HEMS.

RESULTS

The total number of dissected lymph nodes was 227, with an average of 13.3 per patient. The numbers of HN, FN-S, and FN-B were 64, 77, and 34. RI uptake was significantly greater by FN-S than by non-FN-S (P = 0.0016). The median fluorescence intensity value was higher in HN than in non-HN (P < 0.001). A correlation was observed between RI uptake and fluorescence intensity. Dissecting FNs with fluorescence intensity levels of 1-6 resulted in 92.1% dissection of HNs.

CONCLUSION

It is possible that the evaluation of fluorescence intensity is useful for selected SNs instead of RI tracer. If fluorescence intensity is measurable in surgery, an infrared fluorescence method using ICG may be useful and safe for the detection of SN in early gastric cancer.

Clinical application and outcomes of sentinel node navigation surgery in patients with early gastric cancer

Sentinel node navigation surgery (SNNS) has been recognized as a minimally invasive tool for individualized lymphadenectomy in patients with early gastric cancer (EGC). The aim of this study was to compare clinicopathological factors, adverse events, and clinical outcomes between sentinel node mapping (SNM) and SN dissection (SND) groups and assess the clinical utility of SNNS in patients with EGC. The clinical data of 157 patients with EGC, diagnosed as clinical T1N0M0 with tumors ≤ 40 mm, undergoing SNNS between March 2004 and April 2016 were retrospectively reviewed. Twenty-seven patients were excluded from the analysis. In the remaining 130 patients, 59 and 71 patients underwent standard lymphadenectomy for SNM and SND, respectively. The sentinel node detection rate in the SNM and SND groups was 98.3% (58/59) and 100% (71/71), respectively. Two (3.5%), 15 (25.9%), and 41 (70.7%) patients having sentinel nodes underwent total gastrectomy, proximal gastrectomy (PG), and distal gastrectomy (DG), respectively, in the SNM group. One (1.4%), 5 (7.0%), 10 (14.1%), 39 (54.9%), and 16 (22.5%) patients underwent PG, DG, segmental gastrectomy, local resection, and endoscopic submucosal dissection, respectively, in the SND group. There was no significant difference in postoperative complications between the SNM and SND groups (P = 0.781). Survival did not differ between the both groups (P = 0.856). The present results suggest that personalized surgery with SND provides technical safety and curability related with a favorable survival outcome in patients with EGC.

Prognostic significance of preoperative and postoperative CK19 and CEA mRNA levels in peripheral blood of patients with gastric cardia cancer

AIM

To evaluate the clinical and prognostic significance of preoperative and postoperative cytokeratin 19 (CK19) and carcinoembryonic antigen (CEA) mRNA levels in peripheral blood of patients with gastric cardia cancer (GCC).

METHODS

We detected the preoperative and postoperative mRNA levels of CK19 and CEA in peripheral blood of 129 GCC patients by using reverse transcription-polymerase chain reaction and evaluated their clinical and prognostic significance by univariate Kaplan-Meier survival analysis and multivariate Cox proportional hazard analysis. A new prognostic model which stratified patients into three different risk groups was established based on the independent prognostic factors.

RESULTS

Elevated preoperative and postoperative CK19 and CEA mRNA levels in peripheral blood of GCC patients were associated with lymph node metastasis. Univariate analysis showed that tumor size, histological grade, depth of tumor invasion, lymph node metastasis, preoperative CK19 mRNA, and preoperative and postoperative CEA mRNA levels were correlated with the prognosis of GCC patients. The multivariate analysis showed that lymph node status (P = 0.018), preoperative CK19 (P = 0.035) and CEA (P = 0.011) mRNA levels were independent prognostic factors for overall survival (OS). The 5-year OS rates for the low-, intermediate-, and high-risk groups were 48.3%, 22.6%, and 4.6%, respectively (P < 0.001).

CONCLUSION

Elevated preoperative CK19 and CEA mRNA levels may be regarded as promising biomarkers for predicting lymph node metastasis and poor prognosis in patients with GCC. This new prognostic model may help us identify the subpopulations of GCC patients with the highest risk.

Sentinel node biopsy using blue dye and technetium99 in advanced gastric cancer: anatomical drainage and clinical application

Lymph node metastases are an independent prognosis factor in gastric carcinoma (GC) patients. Radical lymphadenectomy can improve survival but it can also increase surgical morbidity. As a principle, sentinel node (SN) navigation surgery can avoid unnecessary lymphadenectomy without compromising prognosis. In this pilot study, 24 patients with untreated GC were initially screened for SN navigation surgery, of which 12 were eligible. Five patients had T2 tumors, 5 had T3 tumors and 2 had T1 tumors. In 33% of cases, tumor diameter was greater than 5.0 cm. Three hundred and eighty-seven lymph nodes were excised with a median of 32.3 per patient. The SN navigation surgery was feasible in all patients, with a median of 4.5 SNs per patient. The detection success rate was 100%. All the SNs were located in N1 and N2 nodal level. In 70.9% of cases, the SNs were located at lymphatic chains 6 and 7. The SN sensitivity for nodal staging was 91.6%, with 8.3% of false negative. In 4 patients who were initially staged as N0, the SNs were submitted to multisection analyses and immunohistochemistry, confirming the N0 stage, without micrometastases. In one case initially staged as negative for nodal metastases based on SN analyses, metastases in lymph nodes other than SN were found, resulting in a 20% skip metastases incidence. This surgery is a reproducible procedure with 100% detection rate of SN. Tumor size, GC location and obesity were factors that imposed some limitations regarding SN identification. Results from nodal multisection histology and immunohistochemistry analysis did not change initial nodal staging.