One-step nucleic acid amplification vs ultrastaging in the detection of sentinel lymph node metastasis in endometrial cancer patients

Diagnostic value of one-step nucleic acid amplification for sentinel lymph node metastasis in cytokeratin 19-positive tumors: evidence from bioinformatics and meta-analysis

Background

The status of the sentinel lymph nodes (SLNs) was an important prognostic factor in varies cancers. A one-step nucleic acid amplification (OSNA) assay, a molecular-based whole-node analysis method based on CK19 mRNA copy number, was developed to diagnose lymph node metastases. We aimed to evaluate the value of OSNA for the diagnosis of sentinel lymph node metastasis in CK19 positive cancers. CK19 mRNA and protein expression for pan-caner analysis were obtained from TCGA and the Human protein atlas database.

Methods

Two researchers independently searched the PubMed, Cochrane Library and Web of Science databases for qualified articles published before December 1, 2023. A meta-analysis was performed using MetaDisc and STATA. Risk bias and quality assessments of the included studies were evaluated, and a subgroup analysis was performed. Ten cancer types were found to be CK19 positively expressed and 7 of 10 had been reported to use OSNA for SLN detection.

Results

After literature review, there were 61 articles included in the meta-analysis, which consisted of 7115 patients with 18007 sentinel lymph nodes. The pooled sensitivity and specificity of OSNA were 0.87 and 0.95 in overall patients. Moreover, we found the background CK19 expression in normal tissue affected the diagnostic accuracy of OSNA. In breast cancer, we performed subgroup analysis. OSNA exhibited to be a stable method across different population groups and various medical centers. In addition, when 250 copies/μl was chosen as the cutoff point of CK19 mRNA, there were a relatively higher sensitivity and AUC in detecting SLN micro-metastasis than 5000 copies/μl.

Discussion

OSNA can predict the occurrence of SLN metastasis accurately in CK19 positive cancers, especially in breast cancer, colorectal cancer, lung cancer, gastric cancer and endometrial cancer. Our study warrants future studies investigating the clinical application of OSNA in pancreatic, ovarian and bladder cancers.

Low-Volume Metastases in Apparent Early-Stage Endometrial Cancer: Prevalence, Clinical Significance, and Future Perspectives

Endometrial cancer (EC) is the most diagnosed gynecologic malignancy, and its incidence and mortality are increasing. The prognosis is highly dependent on the disease spread. Surgical staging includes retroperitoneal evaluation to detect potential lymph node metastases. In recent years, systematic lymphadenectomy has been replaced by sentinel lymph node (SLN) biopsy and ultrastaging, allowing for the detection of macrometastases, micrometastases, and isolated tumor cells (ITCs). Micrometastases and ITCs have been grouped as low-volume metastases (LVM). The reported prevalence of LVM in studies enrolling more than one thousand patients with apparent early-stage EC ranges from 1.9% to 10.2%. Different rates of LVM are observed when patients are stratified according to disease characteristics and their risk of recurrence. Patients with EC at low risk for recurrence have low rates of LVM, while intermediate- and high-risk patients have a higher likelihood of being diagnosed with nodal metastases, including LVM. Macro- and micrometastases increase the risk of recurrence and cause upstaging, while the clinical significance of ITCs is still uncertain. A recent meta-analysis found that patients with LVM have a higher relative risk of recurrence [1.34 (95% CI: 1.07-1.67)], regardless of adjuvant treatment. In a retrospective study on patients with low-risk EC and no adjuvant treatment, those with ITCs had worse recurrence-free survival compared to node-negative patients (85.1%; CI 95% 73.8-98.2 versus 90.2%; CI 95% 84.9-95.8). However, a difference was no longer observed after the exclusion of cases with lymphovascular space invasion. There is no consensus on adjuvant treatment in ITC patients at otherwise low risk, and their recurrence rate is low. Multi-institutional, prospective studies are warranted to evaluate the clinical significance of ITCs in low-risk patients. Further stratification of patients, considering histopathological and molecular features of the disease, may clarify the role of LVM and especially ITCs in specific contexts.

Establishing guidelines for sentinel lymph node ultrastaging in endometrial cancer

BACKGROUND

Many sentinel lymph node (SLN) ultrastaging protocols for endometrial cancer exist, but there is no consensus method.

OBJECTIVE

This study aims to develop guidelines for size criteria in SLN evaluation for endometrial cancer, to determine whether a single cytokeratin AE1:AE3 immunohistochemical slide provides sufficient data for diagnosis, and to compare cost efficiency between current and limited ultrastaging protocols at a large tertiary care institution.

METHODS

Our current SLN ultrastaging protocol consists of cutting two adjacent paraffin block sections at two levels (L1 and L2), 50 μm apart, with two slides at each level stained with hematoxylin and eosin and cytokeratin AE1:AE3 immunohistochemistry. We retrospectively reviewed digitized L1 and L2 slides of all positive ultrastaged SLNs from patients treated for endometrial cancer between January 2013 and January 2020. SLN diagnosis was defined by measuring the largest cluster of contiguous tumor cells in a single cross section: macrometastasis (>2.0 mm), micrometastasis (>0.2 to ≤2.0 mm or >200 cells), or isolated tumor cells (≤0.2 mm or ≤200 cells). Concordance between L1 and L2 results was evaluated. Cost efficiency between current (two immunohistochemical slides per block) and proposed limited (one immunohistochemical slide per block) protocols was compared.

RESULTS

Digitized slides of 147 positive SLNs from 109 patients were reviewed; 4.1% of SLNs were reclassified based on refined size criteria. Complete concordance between L1 and L2 interpretations was seen in 91.8% of SLNs. A false-negative rate of 0%-0.9% in detecting micrometastasis and macrometastasis using a limited protocol was observed. Estimated charge-level savings of a limited protocol were 50% per patient.

CONCLUSION

High diagnostic accuracy in SLN interpretation may be achieved using a limited ultrastaging protocol of one immunohistochemical slide per block and linear measurement of the largest cluster of contiguous tumor cells. Implementation of the proposed limited ultrastaging protocol may result in laboratory cost savings with minimal impact on health outcomes.

Evaluation of the one-step nucleic acid amplification method for rapid detection of lymph node metastases in endometrial cancer: prospective, multicenter, comparative study

OBJECTIVE

To evaluate the diagnostic performance of the one-step nucleic acid amplification (OSNA) method for the detection of sentinel lymph node (SLN) metastases in women with apparent early-stage endometrial cancer compared with standard ultrastaging.

METHODS

Prospective, multicentric, interventional study. Patients with apparent early-stage endometrial cancer who underwent primary surgical staging with SLN mapping were included. SLNs were serially sectioned with 2 mm slices perpendicular to the longest axis of the node: the odd slices were submitted to ultrastaging, whereas the even slices were submitted to the OSNA analysis. Diagnostic performance was calculated taking ultrastaging as referral standard.

RESULTS

Three-hundred and sixteen patients with 668 SLNs were included. OSNA assay detected 22 (3.3%) positive SLNs, of which 17 (2.5%) were micrometastases and 5 (0.7%) macrometastases, whereas ultrastaging detected 24 (3.6%) positive SLNs, of which 15 (2.2%) were micrometastases and 9 (1.3%) macrometastases (p=0.48). Regarding negative SLNs, OSNA detected 646 (96.7%) negative nodes, including 8 (1.2%) isolated tumor cells, while ultrastaging detected 644 (96.4%) negative nodes with 26 (3.9%) isolated tumor cells. Specificity of OSNA was 98.4% (95% CI 97.5 to 99.4), accuracy was 96.7% (95% CI 95.4 to 98.1), sensitivity was 50% (95% CI 30.0 to 70.0), while negative predictive value was 98.1% (95% CI 97.1 to 99.2). Discordant results were found in 22 SLNs (3.3%) corresponding to 20 patients (6.3%). These were 10 (1.5%) false-positive SLNs (all micrometastases): one (0.1%) of these was a benign epithelial inclusion at ultrastaging. There were 12 (1.8%) false-negative SLNs of OSNA, of which 9 (1.3%) were micrometastases and 3 (0.5%) macrometastases. Overall, 17/668 (2.5%) benign epithelial inclusions were detected at ultrastaging.

CONCLUSION

The OSNA method had high specificity and high accuracy in detecting SLN metastasis in apparent early-stage endometrial cancer. The advantage of the OSNA method could be represented as the possibility to analyze the entire lymph node thus eliminating sampling bias.

It is not the time to abandon intraoperative frozen section in endometrioid adenocarcinoma: A large-scale, multi-center, and retrospective study

INTRODUCTION

Stage IB (deep myometrial invasion) high-grade endometrioid adenocarcinoma (EA), regardless of LVSI status, is classified into high-intermediate risk groups, requiring surgical lymph node staging. Intraoperative frozen section (IFS) is commonly used, but its adequacy and reliability vary between reports. Hence, we determined the utility of IFS in identification of high-risk factors, including deep myometrial invasion and high-grade.

METHOD

We retrospectively analyzed 9,985 cases operated with hysterectomy and diagnosed with FIGO stage I/II EA in postoperative paraffin section (PS) results at 30 Chinese hospitals from 2000 to 2019. We determined diagnostic performance of IFS and investigated whether the addition of IFS to preoperative biopsy and imaging could improve identification of high-risk factors.

RESULTS

IFS and postoperative PS presented the highest concordance in assessing deep myometrial invasion (Kappa: 0.834), followed by intraoperative gross examination (IGE Kappa: 0.643), MRI (Kappa: 0.395), and CT (Kappa: 0.207). IFS and postoperative PS presented the highest concordance for high-grade EA (Kappa: 0.585) compared to diagnostic curettage (D&C 0.226) and hysteroscope (Hys 0.180). Sensitivity and specificity for detecting deep myometrial invasion were 86.21 and 97.20% for IFS versus 51.72 and 88.81% for MRI, 68.97 and 94.41% for IGE. These figures for detecting high-grade EA were 58.21 and 96.50% for IFS versus 16.42 and 98.83% for D&C, 13.43 and 98.64% for Hys. Parallel strategies, including MRI-IFS (Kappa: 0.626), D&C-IFS (Kappa: 0.595), and Hys-IFS (Kappa: 0.578) improved the diagnostic efficiencies of individual preoperative examinations. Based on the high sensitivity of IFS, parallel strategies improved the sensitivities of preoperative examinations to 89.66% (MRI), 64.18% (D&C), 62.69% (Hys), respectively, and these differences were statistically significant (p = 0.000).

CONCLUSION

IFS presented reasonable agreement rates predicting postoperative PS results, including deep myometrial invasion and high-grade. IFS helps identify high-intermediate risk patients in preoperative biopsy and MRI and guides intraoperative lymphadenectomy decisions in EA.

Evaluation of the one-step nucleic acid amplification assay for detecting lymph node metastasis in patients with cervical and endometrial cancer: A multicenter prospective study

OBJECTIVE

This multicenter study aimed to evaluate the accuracy of the one-step nucleic acid amplification (OSNA) assay in diagnosing lymph node metastasis (LNM) in patients with cervical and endometrial cancers.

METHODS

Surgically removed LNs from patients with cervical and endometrial cancer were sectioned at 2-mm intervals along the short axis direction and alternately examined using the OSNA assay and conventional histopathological examination. Ultrastaging (200-μm LN sections) was performed for metastatic LNs using hematoxylin and eosin staining and immunostaining with an anti-CK19 antibody in cases where the OSNA assay and histopathological examination (performed using 2-mm LN sections) results showed discordance.

RESULTS

A total of 437 LNs from 133 patients were included; 61 patients (14%) showed metastasis by histopathological examination, with a concordance rate of 0.979 (95% confidence interval [CI]: 0.961-0.991) with the OSNA assay. The sensitivity and specificity of the OSNA assay were 0.918 (95% CI: 0.819-0.973) and 0.989 (95% CI: 0.973-0.997), respectively. Discordance between the two methods was observed in nine LNs (2.1%), and allocation bias of metastatic foci was identified as the major cause of discordance.

CONCLUSIONS

The OSNA assay showed equally accurate detection of LN metastasis as the histopathological examination. We suggest that the OSNA assay may be a useful tool for the rapid intraoperative diagnosis of LN metastasis in patients with cervical and endometrial cancers.

Preoperative and intraoperative assessment of myometrial invasion in patients with FIGO stage I non-endometrioid endometrial carcinoma-a large-scale, multi-center, and retrospective study

INTRODUCTION

Myometrial invasion is a prognostic factor for lymph node metastases and decreased survival in non-endometrioid endometrial carcinoma patients. Herein, we explored the mode of myometrial invasion diagnosis in FIGO stage I non-endometrioid carcinoma and evaluated the differences in diagnostic efficiency among intraoperative frozen section (IFS), intraoperative gross examination (IGE), magnetic resonance imaging (MRI), and computed tomography (CT) in clinical practice. Finally, we suggested which test should be routinely performed.

METHOD

This was a historical cohort study nationwide with 30 centers in China between January 2000 and December 2019. Clinical data, including age, histology, method of myometrial invasion evaluation (MRI, CT, IGE, and IFS), and final diagnosis of postoperative paraffin sections, were collected from 490 non-endometrioid endometrial carcinoma (serous, clear cell, undifferentiated, mixed carcinoma, and carcinosarcoma) women in FIGO stage I.

RESULTS

Among the 490 patients, 89.59% presented myometrial invasion. The methods reported for myometrial invasion assessment were IFS in 23.47%, IGE in 69.59%, MRI in 37.96%, and CT in 10.20% of cases. The highest concordance was detected between IFS and postoperative paraffin sections (Kappa = 0.631, accuracy = 93.04%), followed by IGE (Kappa = 0.303, accuracy = 82.40%), MRI (Kappa = 0.131, accuracy = 69.35%), and CT (Kappa = 0.118, accuracy = 50.00%). A stable diagnostic agreement between IFS and the final results was also found through the years (2000-2012: Kappa = 0.776; 2013-2014: Kappa = 0.625; 2015-2016: Kappa = 0.545; 2017-2019: Kappa = 0.652).

CONCLUSION

In China, the assessment of myometrial invasion in non-endometrioid endometrial carcinoma is often performed via IGE, but the reliability is relatively low in contrast to IFS. In clinical practice, IFS is a reliable method that can help accurately assess myometrial invasion and intraoperative decision-making (lymph node dissection or not). Hence, it should be routinely performed in non-endometrioid endometrial carcinoma patients.

Role of one-step nucleic acid amplification in colorectal cancer lymph node metastases detection

Current histopathological staging procedures in colorectal cancer (CRC) depend on midline division of the lymph nodes (LNs) with one section of hematoxylin and eosin staining. Cancer cells outside this transection line may be missed, which could lead to understaging of Union for International Cancer Control Stage II high-risk patients. The one-step nucleic acid amplification (OSNA) assay has emerged as a rapid molecular diagnostic tool for LN metastases detection. It is a molecular technique that can analyze the entire LN tissue using a reverse-transcriptase loop-mediated isothermal amplification reaction to detect tumor-specific cytokeratin 19 mRNA. Our findings suggest that the OSNA assay has a high diagnostic accuracy in detecting metastatic LNs in CRC and a high negative predictive value. OSNA is a standardized, observer-independent technique, which may lead to more accurate staging. It has been suggested that in stage II CRC, the upstaging can reach 25% and these patients can access postoperative adjuvant chemotherapy. Moreover, intraoperative OSNA sentinel node evaluation may allow early CRC to be treated with organ-preserving surgery, while in more advanced-stage disease, a tailored lymphadenectomy can be performed considering the presence of aberrant lymphatic drainage and skip metastases.

Association between sentinel lymph node biopsy and micrometastasis in endometrial cancer

OBJECTIVE

Sentinel lymph node (SLN) biopsy is increasingly utilized at surgical staging for early endometrial cancer. This study examined the association between SLN biopsy and micrometastasis in endometrial cancer.

METHODS

This is a retrospective cohort study examining the National Cancer Institute's Surveillance, Epidemiology, and End Result Program. The study population was 6,414 women with T1-2 endometrial cancer who underwent primary hysterectomy and surgical nodal evaluation. Exclusion criteria included cases with isolated tumor cells. Exposure assignment was surgical nodal evaluation (SLN biopsy or lymphadenectomy). Main outcome measure was micrometastasis, assessed by inverse probability of treatment weighting propensity score in a stage-specific fashion.

RESULTS

In T1a disease (n = 4,608), SLN biopsy was performed in 1,164 (25.3%) cases. SLN biopsy was associated with a 90% increased likeliness of identifying micrometastasis compared to lymphadenectomy (1.3% versus 0.7%, odds ratio 1.90, 95% confidence interval 1.02-3.55, P = 0.040). In T1b disease (n = 1,369), 270 (19.7%) cases had SLN biopsy. The incidence of micrometastasis was significantly higher in the SLN biopsy group compared to the lymphadenectomy group (8.4% versus 5.0%, odds ratio 1.74, 95% confidence interval 1.06-2.86, P = 0.028). In T2 disease (SLN biopsy in 57 [13.0%] of 437 cases), the incidence of micrometastasis was similar between the two groups (7.9% versus 7.0%, odds ratio 0.88, 95% confidence interval 0.30-2.60, P = 0.818).

CONCLUSION

This study suggests that SLN biopsy protocol may identify more micrometastasis in the regional lymph nodes of T1 endometrial cancer. Whether national-level increase in the utilization of SLN biopsy for early endometrial cancer results in a stage-shifting to advanced disease on a population-basis warrants further investigation.

One-step nucleic acid amplification for intraoperative diagnosis of lymph node metastasis in lung cancer patients: a single-center prospective study

One-step nucleic acid amplification (OSNA) is a rapid intraoperative molecular detection technique for sentinel node assessment via the quantitative measurement of target cytokeratin 19 (CK19) mRNA to determine the presence of metastasis. It has been validated in breast cancer but its application in lung cancer has not been adequately investigated. 214 LNs from 105 patients with 100 primary lung cancers, 2 occult primary lung tumors, and 3 metastatic lung tumors, who underwent surgical lung resection with LN dissection between February 2018 and January 2020, were assessed. Resected LNs were divided into two parts: one was snap-frozen for OSNA and the other underwent rapidly frozen histological examination. Intraoperatively collected LNs were evaluated by OSNA using loop-mediated isothermal amplification and compared with intraoperative pathological diagnosis as a control. Among 214 LNs, 14 were detected as positive by OSNA, and 11 were positive by both OSNA and intraoperative pathological diagnosis. The sensitivity and specificity of OSNA was 84.6% and 98.5%, respectively. The results of 5 of 214 LNs were discordant, and the remainder all matched (11 positive and 198 negative) with a concordance rate of 97.7%. Although the analysis of public mRNA expression data from cBioPortal showed that CK19 expression varies greatly depending on the cancer type and histological subtype, the results of the five cases, except for primary lung cancer, were consistent. OSNA provides sufficient diagnostic accuracy and speed and can be applied to the intraoperative diagnosis of LN metastasis for non-small cell lung cancer.

Application of One-Step Nucleic Acid Amplification (OSNA) in different cancer entities and usefulness in prostate cancer: a systematic review

Background

Lymph node (LN) status is a key prognostic factor in the decision-making process of different cancer entities, including prostate cancer (PCa). Sectioning and haematoxylin and eosin (H&E) staining technique remain the gold standard for the evaluation of LN metastases despite some limitations, especially low sensitivity in detecting an accurate tumour burden within the LN, as well as a subjective and time-consuming result. One-step nucleic acid amplification (OSNA) quantifies mRNA copies of cytokeratin 19 (CK19) in a fast, objective, automated, and reproducible way, raising a general interest to explore its utility for lymphatic metastasis identification in different malignancies.

Methods

To present the latest evidence related to the detection of LN metastases in several tumours by using OSNA compared with the conventional H&E method, a systematic review of articles published since March 2021 was conducted using PubMed, Cochrane Library, and Web of Science databases. References from primary papers and review articles were checked to obtain further potential studies. Our procedure for evaluating records identified during the literature search followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses criteria. With the aim to design and justify future clinical routine use of OSNA in PCa, novel PCa evidence has been included in this review for the first time.

Results

Twenty five studies were included. LN from six different groups of tumours: breast, gastrointestinal, gynecological, lung, head and neck and prostate cancers has been assessed. OSNA was compared with post-operative formalin-fixed paraffin-embedded tissue sections with H&E staining as the reference standard. Contingency tables were created, and concordance rate, sensitivity, specificity and predictive values were reported. Seventeen studies analysed the discordant cases using different techniques.

Conclusion

OSNA method has a high diagnostic accuracy for the detection of LN metastases in several CK19 expressing tumours. Available evidence might encourage future investigations about its usage in PCa patients to improve LN staging and prognosis.

Clinical Study of Sentinel Lymph Node Detection to Evaluate Pelvic Lymph Node Metastasis to Determine the Prognosis of Patients with Early Cervical Cancer

Objective

Lymph node status is one of the most important prognostic factors for uterine cervical cancer. Sentinel lymph node (SLN) biopsy has emerged as a potential alternative to systematic lymphadenectomy for the lymph node mapping in such patients. However, the SLN metastasis detection via SLN biopsy in early-stage cervical cancer remains controversial. The current study is aimed at investigating the feasibility and accuracy of combined tracer method for localization of SLN in initial stages of cervical cancer and to evaluate the clinical value of SLN biopsy in replacing pelvic lymph node resection.

Methods

We retrospectively reviewed 348 cases who were admitted to the Department of Gynecologic Oncology, Shandong Provincial Cancer Hospital, China, between February 2003 and June 2018 with FIGO stage IA2 to IIA2 cervical cancer and undergone through SLN biopsy. Methylthioninium chloride was injected in combination with ^99mtechnetium-labeled sulfur colloid prior to surgery to these patients. SLNs were identified intraoperatively, excised, and subsequently submitted to fast frozen section. The detection rates, accuracy, sensitivity, coincidence rate, false negative rate, and negative predictive values of these cases were estimated, and the follow-up outcomes were carefully observed. Chi squared test or Fisher's exact test was employed for a comparison of the categorical variables. Univariate and multivariate Cox proportional hazard models were used for estimation of relationships between overall survival (OS) and disease-free survival (DFS) and prognostic factors.

Results

The total detection rate of SLN was 97.1% (338/348), and identification of bilateral SLN was successful in 237 patients (70.1%). The patient's tumor size, FIGO stage, lymph node metastasis, and depth of invasion had statistically significant differences in SLN detection rates. The detection rate had inverse relation with tumors size (>4 cm), invasive depth > 2/3, lymph node positive, late staging, and preoperative radiotherapy. 117 positive SLNs were detected in 73 patients. The negative predictive value, sensitivity, false negative rate, and coincidence rate and were 97.7%, 92.4%, 7.6%, and 95.4%, respectively. In patients whose tumor size were ≦ 4 cm, the false negative rate was 4.55% (2/44), whereas it was 0 in patients with tumor size≦2 cm. The respective 1, 3, and 5-year OS was 100%, 94.8%, and 91.8%, respectively, whereas DFS rate for 1, 3, and 5 years was 96.7%, 92%, and 89.6%, respectively. The lymph node was positive, tumor size, the depth of invasion, and staging were statistically different from the recurrence rate and survival rate of patients (p < 0.05). When tumor metastasis exceeded SLN, the recurrence rate was significantly increased, and survival rate is significantly reduced (p < 0.05, p < 0.01, p < 0.05, respectively).

Conclusions

The identification of SLN combined with ^99mtechnetium-labeled sulfur colloid and methylthioninium chloride has a good accuracy and is safe for the assessment of the status of pelvic nodes in patients with initial stage cervical cancer. Nuclide as a tracer has low dependence on objective conditions and doctors' technology and has a good detection rate. In our study, we believe that SLN biopsy is feasible when the tumor is ≦ 4 cm. Large scale clinical trials are required in China expand the sample size and validate the results of this study.

Molecular Cytology by One-Step Nucleic Acid Amplification (OSNA) Assay of Peritoneal Washings during D2 Gastrectomy in Advanced Gastric Cancer Patients: Preliminary Results

The presence of peritoneal free cancer cells (FCC) in gastric cancer (GC) patients is a poor prognostic factor. D2 gastrectomy may induce exfoliated FCC spread from the primary tumour or involved lymph nodes (LN). Conventional cytology for FCC detection has several limitations, whereas prophylactic use of extensive intraoperative peritoneal lavage (IPL) does not improve survival. A prospective single-arm observational study was conducted to verify whether D2 gastrectomy causes an intraoperative increase of FCC in peritoneal fluid. Twenty-seven GC patients underwent D2 gastrectomy, followed by objective quantitative measurements of CK19 mRNA level reflecting FCC with One-Step Nucleic Acid Amplification (OSNA) assay. The IPL with 3000 mL of saline was performed twice: (1) after gastrectomy with D2 lymphadenectomy and (2) after alimentary tract reconstruction. The IPL samples were analysed by initial cytology and four (1-4) consecutive OSNA assays. Initial OSNA measurement (1) revealed positive results (≥24.6 cCP/μL) in 7 (29.6%) patients. Subsequent OSNA measurements showed a significant decrease in the FCC level after D2 gastrectomy (1 vs. 2; p = 0.0012). The first IPL induced a non-significant increase in the FCCs (2 vs. 3, p = 0.3300), but the second IPL reversed it to normal levels (3 vs. 4, p = 0.0.0574). The OSNA assay indicates a temporal intraoperative increase in the peritoneal FCC in advanced GC patients undergoing D2 gastrectomy. Two consecutive IPLs are necessary to reverse the increase of CK19 mRNA level in peritoneal washings.

One-Step Nucleic Acid Amplification (OSNA) of Sentinel Lymph Node in Early-Stage Endometrial Cancer: Spanish Multicenter Study (ENDO-OSNA)

The objective of this study was to evaluate the efficacy of one-step nucleic acid amplification (OSNA) for the detection of sentinel lymph node (SLN) metastasis compared to standard pathological ultrastaging in patients with early-stage endometrial cancer (EC). A total of 526 SLNs from 191 patients with EC were included in the study, and 379 SLNs (147 patients) were evaluated by both methods, OSNA and standard pathological ultrastaging. The central 1 mm portion of each lymph node was subjected to semi-serial sectioning at 200 μm intervals and examined by hematoxylin-eosin and immunohistochemistry with CK19; the remaining tissue was analyzed by OSNA for CK19 mRNA. The OSNA assay detected metastases in 19.7% of patients (14.9% micrometastasis and 4.8% macrometastasis), whereas pathological ultrastaging detected metastasis in 8.8% of patients (3.4% micrometastasis and 5.4% macrometastasis). Using the established cut-off value for detecting SLN metastasis by OSNA in EC (250 copies/μL), the sensitivity of the OSNA assay was 92%, specificity was 82%, diagnostic accuracy was 83%, and the negative predictive value was 99%. Discordant results between both methods were recorded in 20 patients (13.6%). OSNA resulted in an upstaging in 12 patients (8.2%). OSNA could aid in the identification of patients requiring adjuvant treatment at the time of diagnosis.

short review of current implementations of sentinel lymph node mapping in gynecologic cancers

Lymph node metastasis both increases disease stage and alters adjuvant treatment plans in gynecologic cancers. Since a minority of the patients have nodal metastasis, many patients unnecessarily undergo complete lymphadenectomy and are exposed to the subsequent morbidities. Sentinel lymph node (SLN) mapping is an alternative for evaluation of lymph nodes with lesser side effects. Although it is yet an experimental approach in ovarian cancer, it has been incorporated into guidelines for endometrial, cervical and vulvar cancers. We aimed to summarize the current situation of SLN mapping in gynecologic cancers.

Sentinel Lymph Node Mapping in Endometrial Cancer: A Comprehensive Review

Endometrial cancer (EC) is known as a common gynecological malignancy. The incidence rate is on the increase annually. Lymph node status plays a crucial role in evaluating the prognosis and selecting adjuvant therapy. Currently, the patients with high-risk (not comply with any of the following: (1) well-differentiated or moderately differentiated, pathological grade G1 or G2; (2) myometrial invasion< 1/2; (3) tumor diameter < 2 cm are commonly recommended for a systematic lymphadenectomy (LAD). However, conventional LAD shows high complication incidence and uncertain survival benefits. Sentinel lymph node (SLN) refers to the first lymph node that is passed by the lymphatic metastasis of the primary malignant tumor through the regional lymphatic drainage pathway and can indicate the involvement of lymph nodes across the drainage area. Mounting evidence has demonstrated a high detection rate (DR), sensitivity, and negative predictive value (NPV) in patients with early-stage lower risk EC using sentinel lymph node mapping (SLNM) with pathologic ultra-staging. Meanwhile, SLNM did not compromise the patient’s progression-free survival (PFS) and overall survival (OS) with low operative complications. However, the application of SLNM in early-stage high-risk EC patients remains controversial. As revealed by the recent studies, SLNM may also be feasible, effective, and safe in high-risk patients. This review aims at making a systematic description of the progress made in the application of SLNM in the treatment of EC and the relevant controversies, including the application of SLNM in high-risk patients.

Feasibility of Pooled One-Step Nucleic Acid Amplification for Molecular Staging of Pathologically Node-Negative Colon Cancer: A Prospective Multicenter Study

BACKGROUND

Although conventional one-step nucleic acid amplification (OSNA) is a useful molecular-staging method, its complexity hinders its use in clinical practice. A pooled approach for OSNA (pOSNA) has been evaluated for its feasibility in pathologically node-negative colon cancer (pNNCC) for molecular staging of lymph node metastasis in clinical practice.

METHODS

Subjects were patients diagnosed with clinical stage II-IIIA colon cancer between January 2017 and September 2018. pOSNA involved harvesting pericolic lymph nodes from fresh surgical specimens, cutting them in half, placing 50% of the nodes in a single test tube, and performing the OSNA assay. The remaining halved pericolic, intermediate, and main lymph nodes were submitted for histopathologic examination, with metastasis determined by hematoxylin and eosin staining of a cut surface of each node.

RESULTS

Of the 98 enrolled patients, 92 formed the analysis set. The mean number of harvested lymph nodes per case was 24.3 (range 5-66) and the mean number of lymph nodes used for pOSNA analysis was 6.9 (range 1-35). The concordance rate, sensitivity, and specificity between methods were 89.1%, 84.6% (95% confidence interval [CI] 0.80-0.91), and 90.9% (95% CI 0.88-0.94), respectively. The pOSNA upstaging rate for node-negative patients was 9.1% (6/66), and pOSNA returned false-negative results in 15.4% of node-positive cases (4/26).

CONCLUSIONS

pOSNA demonstrated an upstaging rate for pNNCC equivalent to that in previous studies, suggesting its feasibility for molecular staging of pNNCC in clinical practice.

The Diagnostic Accuracy of One-Step Nucleic Acid Amplification for Lymph Node Metastases of Papillary Thyroid Carcinoma： A Systematic Review and Meta-Analysis

BACKGROUND

One-step nucleic acid amplification (OSNA) analysis is a molecular diagnostic technique for lymph node metastases (LNMs) by quantifying cytokeratin 19(CK 19) mRNA. We aim to evaluate the intraoperative diagnostic accuracy of OSNA assay for LNMs of papillary thyroid carcinoma (PTC).

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were searched to retrieve related literature. A meta-analysis was performed using STATA11.0, Meta-Disc 1.4 and RevMan 5.3.

RESULTS

This meta-analysis included six studies involving 987 lymph nodes from 194 patients. The pooled sensitivity, specificity, and area under the summary receiver-operating characteristic curve (AUC) of OSNA for detecting LNM were 0.88, 0.90, and 0.95, respectively.

CONCLUSION

OSNA assay is an accurate molecular diagnosis for intraoperative detection of lymph node metastasis in PTC.

Update on new imaging technologies in sentinel node detection

In most cancers, lymph node status is the most critical factor impacting the evolution of the disease and the overall survival. Identifying potential nodal metastasis allows the oncologist to adjust the stage and, consequently, the patient's treatment. For this reason, a precise evaluation of the regional nodes is mandatory. In gynecological cancers, pelvic, paraaortic, and inguinal nodes are the region most frequently interested by metastasis. In the past years, comprehensive lymphadenectomy was the standard of care for endometrial, cervical, ovarian, and vulvar cancers. However, after introducing the sentinel lymph node (SNL) biopsy in breast cancers, this technique has gained much more interest in gynecology oncology. Several studies have shown that SLN allows an evaluation of the node status without the complications related to the lymphadenectomy that impacts the patient's quality of life. In this review, we discuss the role of SNL biopsy in gynecological cancers and the technique's evolution over the years. Moreover, we debate the OSNA method for SLN analysis that is recently introduced for uterine cancer.

The evolving role of one-step nucleic acid amplification (OSNA) for the intra-operative detection of lymph node metastases: A diagnostic accuracy meta-analysis

BACKGROUND

One Step Nucleic Acid Amplification (OSNA) assay has recently emerged as a rapid molecular diagnostic tool for the detection of lymph node (LN) metastases. It is a molecular technique that analyses the entire LN tissue using a reverse-transcriptase loop-mediated isothermal amplification reaction to detect tumour specific cytoceratin 19 mRNA.

AIM

To ascertain the diagnostic accuracy of OSNA assay in detecting LN metastases amongst different types of malignancy.

DESIGN

We systematically searched MEDLINE, SCOPUS, ClinicalTrials.gov, and Cochrane Database, from inception up to August 2020. Quality assessment was performed using the Modified Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). We calculated pooled diagnostic indices using the random-effects model. Meta-regression and sub-group analyses were performed to address heterogeneity.

RESULTS

31 studies were included in this meta-analysis, including four different types of cancer. The risk of bias and the overall quality of included studies was moderate to high. There was no evidence of publication bias. The pooled diagnostic odds ratio (DOR) for detecting LN metastases in gynaecological, head & neck/thyroid, gastrointestinal and lung cancer were 100.38, 76.17, 275.14, and 305.84, respectively.

CONCLUSIONS

Our findings suggest that OSNA assay had a high diagnostic accuracy in detecting metastatic LNs in different types of malignancy. This evidence is constrained by the limited studies available for few tumour types and the rather high heterogeneity for few outcomes.

Prognostic Significance of Lymph Node Examination by the OSNA Method in Lung Cancer Patients-Comparison with the Standard Histopathological Procedure

The aim of the study was to compare the prognostic significance of lymph node status of patients with lung cancer analyzed by three different methods: hematoxylin and eosin (H&E), immunohistochemistry of cytokeratin 19 (IHC CK19), and One-Step Nucleic Acid Amplification (OSNA). The clinical relevance of the results was evaluated based on relation to prognosis; the disease-free interval (DFI) and overall survival (OS) were analyzed. During radical surgical treatment, a total of 1426 lymph nodes were obtained from 100 patients, creating 472 groups of nodes (4–5 groups per patient) and examined by H&E, IHC CK19 and OSNA. The median follow-up was 44 months. Concordant results on the lymph node status of the H&E, IHC CK19 and OSNA examinations were reported in 78% of patients. We recorded shorter OS in patients with positive results provided by both OSNA and H&E. The study demonstrated a higher percentage of detected micrometastases in lymph nodes by the OSNA method. However, the higher sensitivity of the OSNA, with the cut-off value 250 copies of mRNA of CK19/µL, resulted in a lower association of OSNA positivity with progress of the disease compared to H&E. Increasing the cut-off to 615 copies resulted in an increase in concordance between the OSNA and H&E, which means that the higher cut-off is more relevant in the case of lung tumors.

Can risk groups accurately predict non-sentinel lymph node metastasis in sentinel lymph node-positive endometrial cancer patients? A Turkish Gynecologic Oncology Group Study (TRSGO-SLN-004)

BACKGROUND AND OBJECTIVES

The purpose of this study was to find out the risk factors associated with non-sentinel lymph node metastasis and determine the incidence of non-sentinel lymph node metastasis according to risk groups in sentinel lymph node (SLN)-positive endometrial cancer patients.

METHODS

Patients who underwent at least bilateral pelvic lymphadenectomy after SLN mapping were retrospectively analyzed. Patients were categorized into low, intermediate, high-intermediate, and high-risk groups defined by ESMO-ESGO-ESTRO.

RESULTS

Out of 395 eligible patients, 42 patients had SLN metastasis and 16 (38.1%) of them also had non-SLN metastasis. Size of SLN metastasis was the only factor associated with non-SLN metastasis (p = .012) as 13/22 patients with macrometastasis, 2/10 with micrometastasis and 1/10 with isolated tumor cells (ITCs) had non-SLN metastasis. Although all 4 metastases (1.8%) among the low-risk group were limited to SLNs, the non-SLN involvement rate in the high-risk group was 42.9% and all of these were seen in patients with macrometastatic SLNs.

CONCLUSIONS

Non-SLN metastasis was more frequent in higher-risk groups and the risk of non-SLN metastasis increased with the size of SLN metastasis. Proceeding to complete lymphadenectomy when SLN is metastatic should further be studied as the effect of leaving metastatic non-SLNs in-situ is not known.

Ultrastaging methods of sentinel lymph nodes in endometrial cancer - a systematic review

OBJECTIVE

Sentinel lymph node mapping has emerged as an alternative to lymphadenectomy in evaluating the lymph node status in endometrial cancer. Several pathological methods to examine the sentinel lymph node are applied internationally. The aim of this study was to determine the value of ultrastaging and to assess the ultrastaging method with the highest detection rate of metastases.

METHODS

A systematic review was conducted. Inclusion criteria were: pathologically-confirmed endometrial cancer with sentinel lymph node mapping, report of the histological outcomes, metastases found by hematoxylin and eosin staining and metastases found by ultrastaging were separately mentioned, and description of the ultrastaging method. The primary outcome was the detection of metastases found by ultrastaging that were not detected by routine hematoxylin and eosin staining. The secondary outcome was the difference in detection rate of metastases between several ultrastaging methods. Random effects meta-analyses were conducted.

RESULTS

Fifteen studies were selected, including 2259 patients. Sentinel lymph nodes were examined by routine hematoxylin and eosin staining. Subsequently, multiple ultrastaging methods were used, with differences in macroscopic slicing (bread-loaf/longitudinal), number of microscopic slides, and distance between slides, but all used immunohistochemistry. A positive sentinel lymph node was found in 14% of patients. In 37% of these, this was detected only by ultrastaging. Using more ultrastaging slides did not result in a higher detection rate. Bread-loaf slicing led to a higher detection rate compared with longitudinal slicing (mean detection rates 53% and 33%, respectively).

CONCLUSION

Pathological ultrastaging after routine hematoxylin and eosin staining in endometrial cancer patients has led to an increased detection rate of sentinel lymph node metastases. Different ultrastaging methods are used, with a preference for bread-loaf slicing. However, due to the large heterogeneity of the studies, assessing which ultrastaging method has the highest detection rate of sentinel lymph node metastases was not possible.

Rapid Detection of Free Cancer Cells in Intraoperative Peritoneal Lavage Using One-Step Nucleic Acid Amplification (OSNA) in Gastric Cancer Patients

Cytokeratin-19 (CK19) has been proven to be commonly expressed by cancer cells in a variety of solid tumors and may serve as a suitable marker of metastases in gastric cancer (GC). Since objective assessment of peritoneal lavage or fluid for free cancer cells (FCC) is essential for clinical decision making in patients with GC, it is important to develop a quantitative and reproducible method for such evaluation. We assessed the possible application of One-Step Nucleic Acid amplification (OSNA) assay as a rapid method for FCC detection in intraoperative peritoneal lavage or fluid of GC patients. Seventy-eight intraoperative peritoneal lavage or fluid samples were eligible for the analysis by conventional cytology and OSNA examination. The concentration of CK19 mRNA in intraoperative peritoneal lavage and fluid was compared with the conventional cytological assessment. CK19 mRNA concentration was detected by OSNA assay. For peritoneal lavage samples, sensitivity and specificity were 83.3% and 87.8%, respectively. In peritoneal fluid, significantly higher CK19 values were observed in patients with serosal infiltration (medians: 100 copies/µL vs. 415.7 copies/µL; p = 0.0335) and lymph node metastases (medians: 2.48 copies/µL vs. 334.8 copies/µL). OSNA assay turns out to be an objective, fast, and reproducible quantitative method of FCC assessment.

Standard ultra-staging compared to one-step nucleic acid amplification for the detection of sentinel lymph node metastasis in endometrial cancer patients: a retrospective cohort comparison

INTRODUCTION

The objective of this study was to compared standard ultra-staging (SU) with one-step nucleic acid amplification (OSNA) for the detection of sentinel lymph node (SLN) metastasis in women with apparent uterine-confined endometrial cancer.

METHODS

All women underwent SLN identification with complete surgical staging. All SLNs were cut perpendicular to the long axis and two adjacent 5 µm sections were cut at each of two levels 50 µm apart. At each level, one slide was stained with hematoxylin and eosin and the other with immunohistochemistry using the AE1/AE3 anti-cytokeratin antibody, as well as one negative control slide for a total of five slides per block. For OSNA analysis, the 2 mm sections of the lymph nodes were homogenized to form a lysate. The lysate was then centrifuged and inserted into the RD 100i instrument where the isothermal amplification of CK19 mRNA was executed.

RESULTS

Of the 396 patients included in the retrospective analysis, 214 were in the SU group, and 182 in the OSNA group. Overall 869 SLNs were identified (490 SU, 379 OSNA). Sixty patients exhibited SLN metastasis (34 SU, 26 OSNA). Macrometastasis, micrometastases, and isolated tumor cells (ITC) were 5.1%, 4.1%, and 0.2%, respectively, in the US group, and 2.4%, 6.3%, and 0.1%, respectively, in the OSNA group (p=0.022).

CONCLUSIONS

The OSNA assay detected a higher rate of micrometastasis and a lower rate of macrometastasis and ITC when compared with SU. The clinical and prognostic impact of ITC is debatable and controversial. Further studies are needed to clarify the respective roles of the OSNA and SU methods, and the possible role of ITC in the prognosis of patients with apparent early-stage endometrial cancer.

Frozen section examination of sentinel lymph nodes can be used as a decisional tool in the surgical management of early cervical cancer

INTRODUCTION

Sentinel lymph node (SLN) detection has been shown to be accurate in detecting lymph node involvement in early-stage cervical cancer. The objective of this study was to evaluate the accuracy of frozen section examination in the assessment of SLN status, with the aim of adequately driving the intra-operative decision.

METHODS

We designed a retrospective study including patients from two comprehensive cancer centers between January 2001 and December 2018 with early-stage cervical cancer (IA1-IB2 according to International Federation of Gynecology and Obstetrics (FIGO) 2018) undergoing SLN dissection. The SLN procedure was performed using a cervical injection with technetium-99m combined with blue dye or indocyanine green in most cases.

RESULTS

A total of 176 patients fulfilled inclusion criteria. Bilateral mapping was detected in 153 (86.7%) of them. Nineteen of these patients (12.4%) had SLN involvement: 13 with macrometastases, three with micrometastases and three with isolated tumor cells (ITC). Macrometastatic disease was missed on frozen section in 3/13 FIGO 2018 stage IIIC patients. The three patients with ITC were also missed by frozen section examination.Considering only macrometastases as lymph node involvement, frozen section sensitivity was 76.9% (95% CI 49.7 to 91.8) and negative predictive value (NPV) was 97.9% (95% CI 94.0 to 99.3) in patients with bilateral detection. Including micrometastases, sensitivity was 81.2% (95% CI 57.0 to 93.4) and NPV remained at 97.9% (95% CI 93.9 to 99.3).

CONCLUSIONS

With a prevalence of final-stage IIIC in patients with pre-operative early-stage cervical cancer of the order of 10% in this series, the NPV of frozen section examination of SLN is very high, with an inferior limit of the CI superior to 94%. Diagnostic accuracy remains acceptable even if micrometastases are considered. The impact of missed ITC has not been established. Frozen section examination can be incorporated in the intra-operative decision algorithm.

Accuracy of One-Step Nucleic Acid Amplification in Detecting Lymph Node Metastases in Endometrial Cancer

One-step nucleic acid amplification (OSNA) is used to intraoperatively detect sentinel lymph node metastases in breast cancer. OSNA has also been proposed in endometrial cancer, but evidence in this regard is unclear to define the diagnostic accuracy of OSNA in detecting lymph node metastases in endometrial cancer. A systematic review and meta-analysis was performed by searching 8 electronic databases from their inception to March 2019 for studies testing the diagnostic accuracy of OSNA in detecting sentinel lymph node metastasis in endometrial cancer. Pathologic ultrastaging was the reference standard. Sensitivity, specificity, positive and negative likelihood ratio (LR+ and LR-), diagnostic odds ratio (DOR) and area under the curve (AUC) on SROC curve were calculated. Four studies with 237 patients and 691 lymph nodes were included. OSNA showed sensitivity = 0.88, specificity = 0.93, LR + =17.95, LR- = 0.15, DOR = 191.23 and high diagnostic accuracy (AUC = 0.959). OSNA appears as a highly accurate tool for intraoperative assessment of sentinel lymph node in endometrial cancer.

Intra-operative assessment of sentinel lymph node status by one-step nucleic acid amplification assay (OSNA) in early endometrial cancer: a prospective study

BACKGROUND

Sentinel node mapping has been proposed to reduce surgical side effects, maintaining the accuracy in nodal status assessment for endometrial cancer.

OBJECTIVE

To investigate the role of one-step nucleic acid amplification assay (OSNA) analysis, in the intra-operative tailoring of full nodal dissection, and to analyze the correlation between the type of sentinel node metastasis and the risk of non-sentinel node metastasis.

METHODS

Surgical and pathological data were collected from 141 consecutive, clinical stage I patients with endometrial cancer undergoing surgical staging. Patients were excluded if they had previous pelvic or abdominal radiotherapy, chemotherapy, abdominal cancer, pelvic or abdominal lymphadenectomy, or contraindications to indocyanine green. All sentinel nodes were analyzed by OSNA, and full lymphadenectomy was performed in positive cases. Statistical analysis was performed using Χ² and Fisher's exact test to determine whether any of these characteristics could accurately predict the non-sentinel nodes status in positive sentinel node patients.

RESULTS

A total of 141 patients were included in the analysis. Bilateral sentinel nodes were identified in 104 (73.8%) patients, with a median number of 2 (range 2-6) sentinel nodes per patient. In the remaining 37 patients (26.2%), a unilateral sentinel node was obtained, with a median of 1 (range 1-3) sentinel node per patient. Thirty-three (12.0%) positive nodes were found in 24 (17.0%) patients: micro-metastases and macro-metastases were detected in 22 and 2 patients, respectively. At final pathology, all patients with positive non-sentinel nodes had macro-metastases in the sentinel node, whereas in micro-metastatic sentinel nodes no other positive nodes were found at full lymphadenectomy (p<0.001).

CONCLUSIONS

Our results showed a correlation between the type of metastasis in the sentinel lymph node (SLN) and the incidence of positive non-SLNs. These data suggest a potential role of OSNA analysis in the surgical tailoring of patients with early endometrial cancer, with the goal of definitive risk stratification and a better individualization of adjuvant therapy.