One-step Nucleic Acid Amplification Assay Research Articles

Validation of prognostic and predictive value of total tumoral load after primary systemic therapy in breast cancer using OSNA assay

PurposeThis study aimed to validate the classification of breast cancer (BC) patients in progression risk groups based on total tumor load (TTL) value to predict lymph node (LN) affectation after neo-adjuvant systemic therapy (NAST) obtained in the NEOVATTL study.Methods/patientsThis was an observational, retrospective, international, multicenter study including patients with infiltrating BC who received NAST followed by sentinel lymph node biopsy (SLNB) analyzed with one-step nucleic acid amplification (OSNA) from nine Spanish and two Italian hospitals. Patients were classified into three groups according to the progression risk, measured as disease-free survival (DFS), based on TTL values (> 250, 250–25,000, and > 25,000 copies/μL). The previous (NEOVATTL study) Cox regression model for prognosis was validated using prognostic index (PI) and Log ratio test (LRT) analyses; the value of TTL for axillary non-SLN affectation was assessed using receiver operating characteristic (ROC) curves.ResultsWe included 263 patients with a mean age of 51.4 (± SD 10.5) years. Patients with TTL > 25,000 copies/μL had a shorter DFS (HR 3.561 [95% CI 1.693−7.489], p = 0.0008 vs. TTL ≤ 25,000). PI and LRT analyses showed no differences between the two cohorts (p = 0.2553 and p = 0.226, respectively). ROC analysis showed concordance between TTL and non-SLN involvement (area under the curve 0.828), with 95.7% sensitivity and 92.9% specificity at a TTL cut-off of > 15,000 copies/μL.ConclusionsIn BC patients who had received NAST and underwent SLNB analysis using OSNA, a TTL value of > 25,000 copies/μL was associated with a higher progression risk and > 15,000 copies/μL was predictive of non-SLN involvement.

The Importance of One-step Nucleic Amplification Assay (OSNA) in Early Breast Cancer Patients Who Have Had Upfront Breast Cancer Surgery

Purpose: To audit the diagnostic service at Croydon University Hospital and identify how many newly diagnosed early breast cancer patients with initially clinically node-negative disease had a change in lymph node (LN) status following sentinel lymph node biopsy (SLNB) using one-step nucleic acid amplification assay (OSNA).

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

ObjectiveTo 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...

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

ObjectiveThis 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. MethodsSurgically 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. ResultsA 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. ConclusionsThe 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.

OSNA Total Tumor Load for the Prediction of Axillary Involvement in Breast Cancer Patients: Should We use Different Thresholds According to the Intrinsic Molecular Subtype? MOTTO Study.

To assess the impact of the molecular subtype (MS) on the total number of CK19 mRNA copies in all positive SLN (TTL) threshold, to predict non-SLN affectation, and to compare 5 years progression-free survival (PFS) according to the risk of recurrence (ROR) group by PAM50. Cohort with infiltrating breast cancer with intra-operative metastatic SLN detected by one-step nucleic acid amplification (OSNA) assay who underwent subsequent ALND. Logistic regression was used to assess a possible interaction between TTL and MS(Triple Negative, Her-2-Enriched, Luminal A, or Luminal B), or hormone receptors (HR: positive or negative) by immunohistochemistry (IMH). Cox regression was used to compare PFS and OS in the 3 ROR groups (high, medium, or low). TTL was predictive of non-SLN affectation in both univariate (OR [95% CI]: 1.72 [1.43, 2.05], P < .001) and multivariate (1.55 [95% CI: 1.04, 2.32], P = .030) models, but MS-IMH or HR-IMH, and their interactions with TTL were not (best multivariate model: HR + main effect OR 1.16 [95% CI: 0.18, 7.64], P = .874; interaction OR: 1.04 [0.7, 1.55], P = .835; univariate model: HR + main effect OR: 1.44 [95% CI: 0.85, 2.44], P = .180). PFS was lower in the high-risk ROR group (81.1%) than in the low-risk group (93.9%) (HR: 3.68 [95 CI: 1.70, 7.94], P < .001). our results do not provide evidence to support the utilization of subtype-specific thresholds for TTL values to make therapeutic decisions on the axilla. The ROR group was predictive of 5 years-PFS.

Molecular Detection of Lymph Node Metastases in Lung Cancer Patients Using the One-Step Nucleic Acid Amplification Method:Clinical Significance and Prognostic Value.

The one-step nucleic acid amplification (OSNA) method allows for the quantitative evaluation of the tumor burden in resected lymph nodes (LNs) in patients with lung cancer. This technique enables to detect macro and micrometastases, facilitating the correct classification of patients for appropriate follow-up of the disease after surgery. Of 160 patients with resectable lung cancer whose LNs were examined by OSNA, H&E and CK19 IHC between July 2015 and December 2018, 110 patients with clinical stages from IA1 to IIIB were selected for follow-up. LN staging in lung cancer by pathological study led to understaging in 13.64% of the cases studied. OSNA allowed to quantify the tumor burden and establish a prognostic value. Patients with a total tumor load of ≥1650 cCP/uL were associated with a significantly increased likelihood of recurrence. Moreover, the survival of patients with <4405 cCP/uL was significantly higher than patients with ≥4405 cCP/uL. The OSNA assay is a rapid and accurate technique for quantifying the tumor burden in the LNs of lung cancer patients and OSNA quantitative data could allow to establish prognostic values for recurrence-free survival and overall survival in this type of malignancy.

One Step Nucleic Acid Amplification (OSNA) Lysate Samples Are Suitable to Establish a Transcriptional Metastatic Signature in Patients with Early Stage Hormone Receptors-Positive Breast Cancer.

The One Step Nucleic Acid Amplification (OSNA) is being adopted worldwide for sentinel lymph nodes (SLNs) staging in breast cancer (BC). As major disadvantage, OSNA precludes prognostic information based on structural evaluation of SLNs. Our aim is to identify biomarkers related to tumor-microenvironment interplay exploring gene expression data from the OSNA remaining lysate. This study included 32 patients with early stage hormone receptors-positive BC. Remaining OSNA lysates were prepared for targeted RNA-sequencing analysis. Identification of differentially expressed genes (DEGs) was performed by DESeq2 in R and data analysis in STATA. The results show that, in metastatic SLNs, several genes were upregulated: KRT7, VTCN1, CD44, GATA3, ALOX15B, RORC, NECTIN2, LRG1, CD276, FOXM1 and IGF1R. Hierarchical clustering analysis revealed three different clusters. The identified DEGs codify proteins mainly involved in cancer aggressiveness and with impact in immune response. The overexpression of the immune suppressive genes VTCN1 and CD276 may explain that no direct evidence of activation of immune response in metastatic SLNs was found. We show that OSNA results may be improved incorporating microenvironment-related biomarkers that may be useful in the future for prognosis stratification and immunotherapy selection. As OSNA assay is being implemented for SLNs staging in other cancers, this approach could also have a wider utility.

246 (PB-070) Poster - One-step nucleic acid amplification assay in palpable and non-palpable breast tumours

Background: The one-step nucleic acid amplification (OSNA) assay quantifies the cytokeratin 19 (CK19) messenger RNA copy number, which is currently being used for assessment of axillary sentinel lymph node (SLN) status in breast cancer. The total tumour load (TTL), defined as the total amount of CK19 mRNA copies in all positive SLNs, may help predicting additional metastatic axillary involvement besides SLN. There is evidence suggesting that palpable and non-palpable breast tumours manifest distinct pathological features, making tumour palpability a putative predictive factor of axillary lymph node involvement.

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.

Prognostic value of molecular cytology by one-step nucleic acid amplification (OSNA) assay of peritoneal washings in advanced gastric cancer patients

Peritoneal dissemination is a common form of gastric cancer (GC) recurrence, despite surgery with curative intent. This study aimed to evaluate the prognostic value of intraperitoneal lavage One-Step Nucleic Acid Amplification (OSNA) assay in advanced GC patients. OSNA assay targeting CK-19 mRNA was applied to detect free cancer cells (FCC) in intraperitoneal lavage samples obtained during gastrectomy. A total of 82 GC patients were enrolled to investigate the correlation between OSNA assay and patient’s prognosis. Of the 82 patients, OSNA assay was positive in 25 (30.5%) patients. The median OS in OSNA positive patients was significantly lower than in OSNA negative patients (19 vs 45 months). Positive OSNA assay result was a significant unfavourable prognostic factor in both, univariable (HR 3.45, 95% CI 0.95–12.48; p = 0.0030) and multivariable analysis (HR 3.10, 95% CI 1.22–8.54; p = 0.0298). Positive OSNA assay in intraperitoneal lavage is a valuable indicator of poor survival in advanced GC patients after multimodal treatment. After further confirmation on larger sample size, OSNA assay of peritoneal washings could be considered an adjunct tool to conventional cytology, the current gold standard, to provide precise intraoperative staging and additional prognostic information.

Micrometastasis in lymph nodes of colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide. Postoperative adjuvant chemotherapy is recommended for node‐positive stage III patients. A systematic meta‐analysis reported that the presence of micrometastases in regional lymph nodes (LNs) was associated with poor survival in patients with node‐negative CRC. Because most data employed in the meta‐analysis were based on retrospective studies, we conducted a prospective clinical trial and concluded that stage II is a transitional zone between stage I and stage III, where CRC tumors continuously increase the micrometastasis volume in LNs and proportionally raise the risk for tumor recurrence. The one‐step nucleic acid amplification (OSNA) assay is a simple and rapid technique to detect CK19 mRNA using the reverse‐transcription loop‐mediated isothermal amplification (RT‐LAMP) method. Using the OSNA assay, we and colleagues reported that the upstaging rates of pStages I, IIA, IIB, and IIC were 2.0%, 17.7%, 12.5%, and 25%, respectively, in 124 node‐negative patients. Survival analysis indicated that OSNA positive stage II CRC patients had a shorter 3‐y disease‐free survival rate than OSNA negative stage II CRC patients. In 2017, AJCC TNM staging (the 8th version) revised the definition of LN metastasis in colon cancer and it is stated that micrometastasis should be considered as a standard LN metastasis. To our surprise, this revision was based on a meta‐analysis to which our previous study on micrometastasis largely contributed. The remaining questions to be addressed are how to find micrometastases efficiently and whether postadjuvant chemotherapy is effective to prevent disease recurrence and to contribute to longer survival.

105: SURGICAL DISSECTION DOES NOT INCREASE FREE CANCER CELLS (FCC) IN PERITONEAL LAVAGE OF PATIENTS FOLLOWING D2 GASTRECTOMY

Abstract Background and aim Peritoneal free cancer cells (FCC) in patients with gastric cancer (GC) is poor prognostic factor. D2 gastrectomy dissection may induce exfoliated FCC spread from primary tumour or involved lymph nodes (LN). Conventional cytology for FCC detection has several limitations, and 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 increase of FCC in peritoneal lavage as in patients with GC following D2 gastrectomy. Methods Thirty 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 cc of saline was performed twice after: (1) gastrectomy with D2 lymphadenectomy; and (2) alimentary tract reconstruction. The IPL samples were analysed by initial cytology and four (1–4) consecutive OSNA assays (Figure 1). Three patients were excluded due to positive cytology in samples obtained after laparotomy. Results Initial OSNA measurement (1) revealed positive results (≥24.6 cCP/μl) in 7 (29.6%) patients. Subsequent OSNA measurements revealed a significant decrease in the FCC level after removal of the primary tumour with regional LNs (D2 gastrectomy) (1 vs 2; medians [95%CI]: 4.6 [1.1–18.5] vs. 0.00004 [0–0.2] cCP/μl; P = 0.0012). The first IPL induced non-significant increase in the FCCs (2 vs 3, medians [95%CI]: 0.00004 [0–0.2] vs 0 [0–0.5] cCP/μl; P = 0.3300), but the second IPL reversed it to normal levels (3 vs 4, medians [95%CI]: 0 [0–0.5] vs 0 [0–0] cCP/μl; P = 0.0.0574). At this point of operation, additional finding was a trend toward temporal increase of FCC in patients with LN involvement (pN1–3)(2 vs 3; medians [95%CI]: 0 [0–0.2] vs 0 [0–42.8] cCP/μl; P = 0.0674). One patient was still positive (FCC) at the end of operation as measured by OSNA (4). Conclusion D2 Gastrectomy does not induce increase in the peritoneal FCCs. Temporal intraoperative increase in peritoneal FCC after the IPL may be observed, especially in tumours with LN metastases. At least two consecutive IPLs (with min. 3000 mL of saline) are necessary to reverse temporal increase of peritoneal FCC.

Detection of lymph node metastasis in non-small cell lung cancer using the new system of one-step nucleic acid amplification assay.

IntroductionThe prognosis of non-small cell lung cancer greatly depends on the presence of lymph node metastasis, which limits the need for surgery and adjuvant therapy for advanced cancer. One-step nucleic acid amplification of cytokeratin19 (CK19) mRNA was used to detect lymph node metastasis. Automated Gene Amplification Detector RD-200 and the LYNOAMP CK19 gene amplification reagent as components of the new one-step nucleic acid amplification system, which has increased gene amplification efficiency by improving the reagent composition, have shorter preprocessing and measurement times than conventional systems. We aimed to compare the clinical performance of the new system with that of histopathology and the conventional system.Materials and methods199 lymph nodes from 58 non-small cell lung cancer patients who underwent lymph node dissection were examined intraoperatively using the new system, conventional system, and histopathology.ResultsLymph node metastasis was diagnosed in 32, 42, and 44 patients using histopathological analysis, the new system, and the conventional system, respectively. Compared with histopathological analysis, the concordance rate, sensitivity, specificity, positive predictive value, and negative predictive value of the new system were 92.0%, 90.6%, 92.2%, 69.0%, and 98.1%, respectively, and compared with the conventional system, the values were 95.0%, 86.4%, 97.4%, 90.5%, and 96.2%, respectively.ConclusionThe clinical performance of the new one-step nucleic acid amplification system in detecting lymph node metastasis of lung cancer is comparable to that of histopathology and the conventional system; its performance was sufficient for determining the appropriate clinical treatment. The new rapid system can be effectively utilized during lung cancer treatment intraoperatively and postoperatively.

Can one-step nucleic acid amplification assay predict four or more positive axillary lymph node involvement in breast cancer patients: a single-centre retrospective study.

One-step nucleic acid amplification (OSNA) assay is a proven, accurate, intraoperative method for the detection of lymph node (LN) metastases. The aim of this study was to assess if the total tumour load (TTL) as calculated by OSNA could be used to predict N2 stage disease, ie ≥4 LN containing metastases, in invasive breast cancer patients. Between 2011 and 2019 at St Richard's Hospital, Chichester, all macro-metastasis-positive OSNA cases for invasive breast cancer were retrospectively reviewed. The association between clinicopathological variables and ≥4 LNs containing metastases was analysed using regression analysis. In total, 134 patients with positive sentinel lymph node (SLN) on OSNA undergoing axillary node clearance were analysed, 53% of whom had no further positive LN, 25% had ≥4 lymph nodes positive. TTL was calculated as the aggregate of cytokeratin-19 mRNA copy count of all SLN tissue analysed via OSNA. TTL ≥1.1×105copies/μl and lymphovascular invasion (LVI) were both significant predictors of N2 stage disease on both univariate (TTL p=0.04, LVI p=0.005) and multivariate (TTL p=0.008, LVI p=0.039) regression analysis. Our findings show that SLN TTL via intraoperative OSNA assay can predict four or more positive axillary LN involvement in invasive breast cancer. This is important in that it may be used intraoperatively by surgeons to decide on whether to proceed with a full axillary node clearance in order to stage the axilla. Further research is required to shape future guidance.

A prediction model for early systemic recurrence in breast cancer using a molecular diagnostic analysis of sentinel lymph nodes: A large-scale, multicenter cohort study.

BackgroundThe one‐step nucleic acid amplification (OSNA) assay can quantify the cytokeratin 19 messenger RNA copy number as a proxy for sentinel lymph node (SN) metastasis in breast cancer. A large‐scale, multicenter cohort study was performed to determine the prognostic value of the SN tumor burden based on a molecular readout and to establish a model for the prediction of early systemic recurrence in patients using the OSNA assay.MethodsSN biopsies from 4757 patients with breast cancer were analyzed with the OSNA assay. The patients were randomly assigned to the training or validation cohort at a ratio of 2:1. On the basis of the training cohort, the threshold SN tumor burden value for stratifying distant recurrence was determined with Youden's index; predictors of distant recurrence were investigated via multivariable analyses. Based on the selected predictors, a model for estimating 5‐year distant recurrence–free survival was constructed, and predictive performance was measured with the validation cohort.ResultsThe prognostic cutoff value for the SN tumor burden was 1100 copies/μL. The following variables were significantly associated with distant recurrence and were used to construct the prediction model: SN tumor burden, age, pT classification, grade, progesterone receptor, adjuvant cytotoxic chemotherapy, and adjuvant anti–human epidermal growth factor receptor 2 therapy. The values for the area under the curve, sensitivity, specificity, and accuracy of the prediction model were 0.83, 63.4%, 81.7%, and 81.1%, respectively.ConclusionsUsing the OSNA assay, the molecular readout–based SN tumor burden is an independent prognostic factor for early breast cancer. This model accurately predicts early systemic recurrence and may facilitate decision‐making related to treatment.

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

BackgroundOne-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).MethodsPubMed, 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.ResultsThis 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.ConclusionOSNA assay is an accurate molecular diagnosis for intraoperative detection of lymph node metastasis in PTC.

One-step nucleic acid amplification (OSNA) assay for detecting lymph node metastasis in cervical and endometrial cancer: a preliminary study.

ObjectiveTo evaluate the accuracy of the one-step nucleic acid amplification (OSNA) assay for the diagnosis of lymph node (LN) metastasis in uterine cancer.MethodsA total of 116 LNs from 30 patients with cervical and endometrial cancer, enrolled in this prospective study, were used. Excised LNs were cut into 4 to 6 blocks at 2 mm intervals, and nonadjacent blocks were alternately subjected to either histological examination or the OSNA assay.ResultsThe concordance rate between histological examination and the OSNA assay in cervical cancer and in endometrial cancer was 95.9% and 95.2%, respectively. The sensitivity, specificity, and negative predictive value of the OSNA assay were 80%, 97.7%, and 97.7% in cervical cancer, and 85.7%, 93.3%, and 98.2% in endometrial cancer, respectively. In cervical cancer, discordant results were observed in 2 out of 49 LNs (4.1%); 1 was OSNA assay-positive and histological examination-negative, and 1 was OSNA assay-negative and histological examination-positive. In endometrial cancer, discordant results were observed in 5 out of 67 LNs (7.5%); 4 were OSNA assay-positive and histological examination-negative, and 1 was OSNA assay-negative and histological examination-positive.ConclusionThe OSNA assay showed high concordance rate with histological examination, sensitivity, and specificity in uterine cancer, suggesting that it could enhance the accuracy of conventional pathological examination for the detection of LN metastasis by reducing false negative rate.

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).

Simple SummaryOne-step nucleic acid amplification (OSNA) is an automated molecular diagnostic assay used to detect metastases by analyzing the levels of cytokeratin 19 mRNA in whole lymph nodes. It has been validated as an accurate and reliable tool for staging in several types of cancers and is included in the National Institute for Health and Care Excellence guidelines for the management of breast cancer. ENDO-OSNA is a large, observational, multicenter study designed to evaluate the efficacy of OSNA for the detection of sentinel lymph node (SLN) metastasis in patients with early-stage endometrial cancer. We found that the OSNA assay shows higher sensitivity, specificity, and diagnostic accuracy in the detection of SLN metastasis, including low-volume metastasis, compared to standard pathological ultrastaging. Moreover, OSNA could aid in the identification of patients with intermediate or high-risk endometrial cancer, and lead to treatment decisions that could improve their prognosis.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.

MP60-20 DETECTION OF LYMPH NODE METASTASES USING POOLING METHOD BY ONE-STEP NUCLEIC ACID AMPLIFICATION (OSNA) ASSAY IN PROSTATE CANCER PATIENTS: PRELIMINARY RESULTS FROM A PROSPECTIVE-MULTICENTRE STUDY

MP60-20 DETECTION OF LYMPH NODE METASTASES USING POOLING METHOD BY ONE-STEP NUCLEIC ACID AMPLIFICATION (OSNA) ASSAY IN PROSTATE CANCER PATIENTS: PRELIMINARY RESULTS FROM A PROSPECTIVE-MULTICENTRE STUDY