One-step Nucleic Acid Amplification Method Research Articles

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...

Intraoperative evaluation of metastases in sentinel nodes through one-step nucleic acid amplification: Initial experience in asingle institution.

The objective of this study was to gain our initial experience in one-step nucleic acid amplification (OSNA) for detecting sentinel lymph node (SLN) metastasis as compared to standard pathological staging in patients with breast cancer. Fifteen patients with preoperatively confirmed early breast cancer eligible for breast‑saving therapy and sentinel lymph node biopsy (SLNB) were enrolled in the study. Lymphatic mapping and SLNs detection were performed through the magnetic method. Excised SLNs were intraoperatively examined through OSNA and frozen‑section methods. All lymph nodes were postoperatively examined through histopathology and immunohistochemistry. The results of latter methods were correlated. Our initial experience proved OSNA to be a sensitive and efficient alternative to intraoperative assessment of metastases in SLN in breast cancer patients. Moreover, the information obtained by the OSNA method provides the surgeon with the possibility of assessing a more accurate prognosis during the initial surgery (Tab. 3, Fig. 4, Ref. 36). Text in PDF www.elis.sk Keywords: breast cancer, metastases, surgery, sentinel nodes, OSNA.

One step nucleic acid amplification (OSNA) for detection of lymph node metastasis during robotic radical prostatectomy for prostate cancer: A pilot study

The OSNA technique is based on reverse transcription loop-mediated DNA amplification for the detection of cytokeratin 19 (CK19) messen-ger RNA (mRNA). The purpose of our paper, which represents the first study in the literature, is to test the accuracy of this method in the detection of lymph node metastases in patients undergoing robotic radical prostatectomy with lymph node dis-section. Our cohort consisted of patients that have undergone robotic radical prostatectomy with extended lymph node dissec-tion. Lymph nodes were evaluated with imprint technique and then with frozen section examination. The remaining tissue was evaluated by OSNA method. Lymph nodes were defined as 'neg-ative' or 'positive' according to mRNA copy number. 7 patients and 25 lymph nodes were included in our cohort. Two patients were found negative with all pathology methods. In one patient the standard stains revealed a suspi-cious outcome but it was positive for micrometastasis with OSNA. In another patient the outcome was positive for standard stains and negative for OSNA. Finally, 2 patients were found positive for OSNA and negative for imprint methods. One Step Nucleic Acid Amplification (OSNA) method using CK19 seems to fail in detection of lymph node metastases in prostate cancer patients undergoing radical prostatectomy and lymph node dissection.

One-Step Nucleic Acid Amplification System in Comparison to the Intraoperative Frozen Section and Definitive Histological Examination Among Breast Cancer Patients: A Retrospective Survival Study.

Simple SummaryImplementing intraoperative assessment of sentinel lymph nodes by one-step nucleic acid amplification in early breast cancer can reduce the surgical burden to the patient and the costs to the health system. However, only limited data are available in terms of long-term disease-free survival and overall survival. Therefore, this study aims to compare disease-free survival and overall survival between one-step nucleic acid amplification, frozen section, and definitive histology. These results could impact the healthcare community, adding further proof to the body of evidence supporting the broader adoption of this innovative technology that enables a safe reduction in patient surgical burden and healthcare costs.BackgroundThe one-step nucleic acid amplification (OSNA) system is a novel molecular technique, which consents to quick intraoperative detection of sentinel lymph node metastases by the amplification of cytokeratin 19 mRNA. Our study aims to evaluate the OSNA method in comparison with frozen section (FS) and definitive histological examination of the sentinel lymph node biopsy among early breast cancer patients considering disease-free survival (DFS) and overall survival (OS).MethodsIn this study, we included all women who underwent sentinel lymph node biopsy (SLNB) for breast cancers classified as TNM stage I and II in our center between January 2005 and January 2017, and the follow-up was collected up to January 2019. We divided patients among three groups based on SLNB evaluation: definitive histological examination, intra-operative FS, or OSNA.ResultsWe included 2412 SLNBs: 727 by definitive histological examination, 697 by FS, and 988 by OSNA. Isolated tumor cells were found in 2.32% of cases, micrometastasis in 9.12%, and macrometastases in 13.64%. Surgical procedure duration was significantly shorter in OSNA than in FS (42.1 minutes ±5.1 vs. 70.1 minutes ±10.5, p <0.05). No significant differences have been observed among the three groups regarding OS, DSF, cumulative local, or distant metastases. In particular 5-year DFS was 96.38% in definitive histology (95% C.I. 95.02-97.75%), 96.37% in FS (95% C.I. 94.98-97.78%), and 96.51% in OSNA group (95% C.I. 95.32-97.72%).ConclusionsNo difference in OS and DFS was found comparing OSNA, FS, and definitive histology. Furthermore, reduced operative time was found in the OSNA group.

Prediction of lateral lymph node metastasis using OSNA method for mesorectal lymph nodes in low rectal cancer: A prospective study by the Kanagawa Yokohama Colorectal Cancer Study Group (KYCC1801).

Contrary to the Japanese guidelines recommendations regarding lateral lymph node dissection (LatLND) for rectal cancer, its omission is common in clinical practice without reliable omission criteria. Negative pathological mesorectal lymph node metastasis (MesLNM) is reportedly highly correlated with negative pathological lateral lymph node metastasis (p-LatLNM); however, this cannot be used as a criterion because pathological features are revealed postoperatively. Herein, we prospectively evaluated the negative predictive value (NPV) of MesLNM diagnosed via the one-step nucleic acid amplification (OSNA) method for p-LatLNM. This prospective study was conducted at a single academic study group in Japan. The key eligibility criterion was mid-to-low rectal cancer planned to be treated using mesorectal excision with LatLND. According to the study protocol, the OSNA method was considered useful if the point estimate of the NPV exceeded 95%. Preoperative case registration was conducted between 2018 and 2020; 34 patients were registered. Among these, 16 were negative for OSNA-MesLNM, and negative p-LatLNM was confirmed in all cases. The point estimate of the NPV was 100%, with the 95% confidence interval ranging from 79.4% to 100.0%. The OSNA method is useful in selecting patients in whom LatLND can be omitted in real-world clinical practice.

Ultrastaging Using Ex Vivo Sentinel Lymph Node Mapping and One-Step Nucleic Acid Amplification (OSNA) in Gastric Cancer: Experiences of a European Center.

Simple SummaryIn this study, the effectiveness of One-step nucleic acid amplification (OSNA) in combination with ex vivo SLN mapping is compared with conventional histology including immunohistochemistry. OSNA lymph node evaluation has been performed in 41 gastric cancer cases. It showed a high effectiveness with sensitivity, specificity, and accuracy rates of 85.4%, 93.5%, and 92.4%, respectively The LN status could be predicted in 40 cases and led to upstaging in three cases (14%). The OSNA method proved its potential to increase the sensitivity of metastases detection.Background: In this study, the effectiveness of One-step nucleic acid amplification (OSNA) in combination with ex vivo SLN mapping is compared with conventional histology including immunohistochemistry. Methods: LNs were retrieved from gastrectomy specimens in an unfixed state. After ex vivo SLN mapping using methylene-blue, LNs were sliced to provide samples for histology and OSNA. Results: In total, 334 LNs were retrieved in the fresh state from 41 patients. SLN detection was intended in 40 cases but was successful in only 29, with a correct LN status prediction in 23 cases (79%). Excluding one case out of 41 with a failure likely caused by a processing error, OSNA showed a high effectiveness with sensitivity, specificity, and accuracy rates of 85.4%, 93.5%, and 92.4%, respectively. The LN status could be predicted in all but one case, in which the single positive LN was not eligible for OSNA testing. Moreover, OSNA evaluation led to upstaging from N0 to N+ in three cases (14%). Conclusion: The ex vivo SLN protocol used resulted in a relatively poor detection rate. However, the OSNA method was not hampered by this detection rate and proved its potential to increase the sensitivity of metastases detection.

ISCAN: An RT-LAMP-coupled CRISPR-Cas12 module for rapid, sensitive detection of SARS-CoV-2

The COVID-19 pandemic caused by SARS-CoV-2 affects all aspects of human life. Detection platforms that are efficient, rapid, accurate, specific, sensitive, and user friendly are urgently needed to manage and control the spread of SARS-CoV-2. RT-qPCR based methods are the gold standard for SARS-CoV-2 detection. However, these methods require trained personnel, sophisticated infrastructure, and a long turnaround time, thereby limiting their usefulness. Reverse transcription-loop-mediated isothermal amplification (RT-LAMP), a one-step nucleic acid amplification method conducted at a single temperature, has been used for colorimetric virus detection. CRISPR-Cas12 and CRISPR-Cas13 systems, which possess collateral activity against ssDNA and RNA, respectively, have also been harnessed for virus detection. Here, we built an efficient, rapid, specific, sensitive, user-friendly SARS-CoV-2 detection module that combines the robust virus amplification of RT-LAMP with the specific detection ability of SARS-CoV-2 by CRISPR-Cas12. Furthermore, we combined the RT-LAMP-CRISPR-Cas12 module with lateral flow cells to enable highly efficient point-of-care SARS-CoV-2 detection. Our iSCAN SARS-CoV-2 detection module, which exhibits the critical features of a robust molecular diagnostic device, should facilitate the effective management and control of COVID-19.

A more sensitive detection of micrometastases of NSCLC in lymph nodes using the one‐step nucleic acid amplification (OSNA) method

Detection of tumor cells in lymph nodes (LNs) removed during the treatment of pulmonary tumor by radical surgery is limited by the possibilities of standard histopathological methods. The goal of this study was to obtain more accurate pTNM status by a more sensitive detection of micrometastases in LNs. A total of 885 LNs, an average of 13.8 LNs per patient, were removed during 64 surgeries. LNs from the same zone were pooled together as a group, five groups of LNs were examined in each patient. A total of 320 groups of LNs were examined. One-step nucleic acid amplification (OSNA) method was compared to standard histopathological examination with haematoxylin-eosin (H&E) staining and CK19 immunohistochemistry, specifically by an ultimate analysis of all intraoperatively removed LNs. Identical results for H&E and OSNA examinations were recorded in 286 groups of LNs (89.4%). In total, positive examinations were recorded in 27 groups of LNs (8.4%) using the OSNA method, which were H&E negative. In seven groups of LNs (2.2%), the H&E examination was positive, while OSNA method produced negative results. The OSNA examination led to a higher pTNM stage classification in 14 (21.9%) patients. The clinical significance remains the subject of follow-up research.

P223 - Study of axillary lymph node staging based on a combined used of histology and one-step nucleic acid amplification method for breast cancer patients without axillary lymph node dissection

P223 - Study of axillary lymph node staging based on a combined used of histology and one-step nucleic acid amplification method for breast cancer patients without axillary lymph node dissection

Recent advances in sentinel node biopsy in breast surgery.

Sentinel lymph node (SLN) biopsy has become the standard of care for early breast cancers throughout the world. It provides the breast cancer patients with the safety and benefit of a highly accurate and less-morbid axillary staging, thereby avoiding the uncomfortable side effects of unnecessary axillary dissection. Recently, SLN biopsy was successfully performed in patients undergoing neoadjuvant chemotherapy. However, the methods used for SLN biopsy, and for the evaluation of cancer metastasis in SLN are not still fully established. Ordinarily, a positive SLN (macrometastasis and micrometastasis) indicates further axillary lymph node dissection; however, recent reports have shown that this may not be true for all cases. Also, the prognostic significance of macrometastasis, micrometastasis and isolated tumor cells (ITC) in SLN are still unclear. In the first review, Dr. Motomura has presented an overview of the past, present, and future of SLN biopsy for breast cancers. The clinical significance of micrometastasis in sentinel nodes, the prevention of axillary lymph node dissection in patients with positive sentinel nodes, neoadjuvant chemotherapy and sentinel node biopsy, as well as future perspectives are discussed in this review. In the second review by Dr. Tsuda, the histopathological aspects of sentinel lymph nodes have been presented. He described the classification of macrometastasis, micrometastasis, and ITC, as well as the practice of intraoperative pathological diagnosis of SLN metastasis. In addition, the clinical implications of micrometastasis and ITCs in SLNs are discussed. In the third review, Dr. Tamaki described a recently developed new method for the detection of cancer metastasis in SLN; the one step nucleic acid amplification (OSNA) method. Based on several original articles, the reliability of the OSNA method has been compared with the histopathological method, and clinical use of OSNA method in SLN biopsy was presented. I advise the readers to read and compare the present issues and the past issues, entitled ‘‘Recent trends concerning sentinel lymph node biopsy for breast cancer and new methods for detection of metastasis’’ in Breast Cancer, Vol. 14, No. 4, 2007.

Cytokeratin 19 expression in primary thoracic tumors and lymph node metastases

BackgroundThe use of one-step nucleic acid amplification (OSNA), which allows for the rapid intraoperative detection of lymph node (LN) metastasis, is becoming more widely accepted in breast cancer. To provide basic data for the development of this method for lung tumors, we conducted a large-scale investigation of cytokeratin (CK) 19 expression in thoracic tumors. Patients and methodsWe examined CK19 expression in specimens from a total of 801 surgically resected samples of primary lung adenocarcinoma (ADC), squamous cell carcinoma (SQC), large-cell carcinoma (LCC), pleomorphic carcinoma (PC), large cell neuroendocrine carcinoma (LCNEC), small cell carcinoma (SCC), and carcinoid tumor (CT) as well as pleural malignant mesothelioma and lung metastatic deposits from breast cancer using tissue microarrays (TMAs) and whole sections. We also compared the CK19 expression status between primary sites and LN metastatic deposits. ResultsThe overall rate of CK19 expression as observed on TMAs and whole sections in the 801 analyzed cases was 88.0%. CK19 expression was detected in 94.6% of ADCs, 93.6% of SQCs, 54.5% of LCCs, 54.8% of PCs, 77.4% of LCNECs, 31.8% of SCCs, 34.0% of CTs, and 92.9% of malignant mesotheliomas. Expression of CK19 was also detected in 90.9% of lung metastatic deposits from breast carcinomas. CK19 expression was maintained between CK19-positive primary sites and the corresponding LN metastatic deposits. Of note, a portion of CK19-negative primary tumors showed upregulation of CK19 protein expression in LN metastases. ConclusionsMost thoracic tumors, except for PCs, CTs, and SCCs, were positive for CK19. We also found that CK19 expression was maintained between CK19-positive primary tumors and the corresponding LN metastatic deposits. These results may be useful in the development of the OSNA method for the intraoperative detection of LN metastasis in non-small cell lung cancer (NSCLC).

Abstract P1-01-06: Elaboration of a nomogram to predict the non sentinel node status (NSN) in breast cancer (BC) patients with positive SN, intra-operatively assessed with OSNA (one step nucleic acid amplification) method

Abstract BACKGROUND Diagnostic axillary lymph node dissection (ALND) has been replaced by sentinel node biopsy (SNB) in nodal staging. Tumor-positive SNB results in a risk of NSN metastases in case of micro and macro metastases ranging from 10 to 50% respectively. Therefore most of the patients are submitted to an unnecessary ALND. Therefore the development of a mathematical model for predicting patient-specific risk of non sentinel node metastases is strongly warranted. We have developed an European Database with positive SN detected by OSNA molecular method, able to identify intra-operatively patients with micro (CK19 mRNA copies 250-5000) or macrometastases (number of copies &amp;gt; 5000). MATERIAL AND METHODS European OSNA database has been developed, only patients whose SN was totally assessed with OSNA were included. The following parameters were recorded: - Clinical: hospital, age, record number - Bio-patological: tumor size, grading, multifocality, histological type, LVI, ER-PR status, HER-2, KI67, molecular classification (luminal A, luminal B, HER2 like, triple negative) - Sentinel and non-sentinel lymph node related: number of removed SNs, number of positive and negative SNs, copy number of positive sentinel node, ratio: number of positive SN to number of removed SN number of removed and number of positive nodes after ALND. A total of 2351 patients have been included in the database (938 micrometastases and 1413 macrometastases) with the collaboration of 20 European and Italian OSNA centers. Univariate analysis was performed to determine factors associated with NSN metastases. Chi-square test was used for categorigal variables. All variables with p values less than 0.05 were included in the logistic analysis using backward stepwise method. RESULTS Univariate and multivariate analysis for micro and macro metastases are reported. In patients with SN micrometastases, multivariate analysis showed that grading (p&amp;lt;0.006), Tsize (p&amp;lt;0.04) and the number of CK19 mRNA copies (p&amp;lt;0.0001) are strictly related with positivity of NSN status. In patients with macrometastases multivariate analysis selected KI 67 (p&amp;lt;0.04), Tsize (p&amp;lt;0.002), number ofcopies (p&amp;lt;0.0001) and multifocality (p&amp;lt;0.007) as parameters significantly correlated with NSN positivity. CONCLUSIONS In our analysis we have evaluated only parameters available at the time of operation because the final nomogram has to be employed by the surgeons as a guide for the surgical decision-making whether to perform or not ALND in BC women. The large population employed and the power of number of copies are the right prerequisites for a reliable nomogram that will be presented at the Meeting. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-01-06.

Advantages of one step nucleic acid amplification (OSNA) whole node assay in sentinel lymph node (SLN) analysis in breast cancer

BackgroundThe purpose of this study is to present our first results of sentinel node analysis (SLN) by one step nucleic acid amplification (OSNA) in routine clinical practice in our centre and compare them with the results of classic histopathological analysis in a historical cohort from our same institution.Methods407 patients (total study population) with early breast cancer and no clinical nodal involvement underwent SLN biopsy in our institution. The SLN was analysed by OSNA in 164 biopsies. OSNA results were compared with the conventional histopathology study of 244 patients who had undergone SLN biopsy previously. The characteristics of the patients in both groups were evaluated and a comparison was made of the rate of metastases detected by both methods and of the surgical procedures needed in each group. We also investigated the state of non-sentinel lymph nodes if micrometastases where found in SLN.ResultsSLN biopsy result was considered as positive in 45 patients (28%) in the OSNA group and in 58 in the historical group (24%). There was no difference in the rate of macrometastases (16,5% for OSNA, 20% for HE) but we found differences in the rate of micrometastases (11% for OSNA and 3,6% for HE p = 0.0007). Axillary lymphadenectomy (ALND) was performed in 43/45 cases in the OSNA group and in 51/58 of the historical group. In all patients diagnosed by OSNA, ALND was performed during the initial surgical procedure. In the historical cohort ALND was performed during the initial surgical procedure in 41 patients and in a second surgical procedure in 10 patients. Patients from both groups with micrometastases in the SLN had no metastases in other nodes when the ALND was performed.ConclusionsOSNA analysis allows the detection of SLN metastases as precisely as conventional pathology with an increased detection of micrometastases. The OSNA method can reduce the need of a deferred lymphadenectomy.

Comparison of one-step nucleic acid amplification (OSNA) method and routine histological investigation for intraoperative detection of lymph node metastasis in Polish women with breast cancer

Sentinel lymph node (SLN) biopsy is a part of the staging procedure in breast cancer patients. Intraoperative molecular analysis for SLN metastases using the one-step nucleic acid amplification (OSNA) method based on reverse-transcription loop-mediated amplification (RT-LAMP) has already been validated in breast cancer. In this study, we compare the intraoperative OSNA method to our routine histological investigation. To evaluate the performance of OSNA in comparison to histology, analysis of 74 SLN from 60 breast cancer patients was conducted with both methods. Of the 22 histologically positive samples, 14 were attributed to macrometastases (++) in the OSNA-CK19 assay and 8 to micrometastases (+). Two samples negative in histopathology were positive in the OSNA method (micrometastases +). Our results show that OSNA is an excellent method for the detection of metastases in lymph nodes and can be applied as an intraoperative diagnostic approach. Intraoperative molecular analysis for SLN metastases using the OSNA method reduces the number of admission days and duration of surgery. To our knowledge this is the first study referring to Polish women.

CK19 testing prior to OSNA analysis: to stain or not to stain?

Dear Editor, We read with interest the article by Vilardell et al. [1] where lymph node metastasis was missed in a patient with a cytokeratin-19 (CK19)-negative breast cancer. Sentinel node biopsy (SNB) is currently the standard practice for staging the axilla [2], with one-step nucleic acid amplification (OSNA) becoming more widely accepted [3] and used in clinical practice. OSNA detects metastasis by quantifying the presence of CK19 mRNA, in theory irrespectively whether this is expressed or not. There are limited data regarding the true incidence of CK19-negative tumours. The authors estimate this to be about 3 %, which is probably similar to anecdotal data in our practice. Our institution was second in the UK to adopt OSNA analysis routinely in its practice. Since May 2010, nearly 600 such procedures have been performed. However, in contrast with Vilardell, we identified a patient who, despite both the core biopsy and the subsequent breast excision specimen testing negative for CK19 expression, was found to have SNB micrometastasis on OSNA analysis. The tumour biopsy confirmed an oestrogen and progesterone receptor-positive ductal carcinoma (ER8/8, PR 6/8), with negative HER2 immunohistochemistry. Retrospective Ki67 proliferative index was found at 10 %, confirming the tumour’s luminal A immunophenotype. CK19 was negative despite repeated testing in the presence of positive controls. Intraoperative full-node OSNA analysis of two sentinel nodes showed one negative lymph node and one with micrometastasis (820 copies of CK19 mRNA). As per hospital practice at the time, the patient proceeded to completion axillary lymph node dissection. Final histology confirmed a 10-mm grade 2 invasive ductal carcinoma, with few foci of ductal carcinoma in situ. Ten further lymph nodes were identified, with no evidence of metastatic disease. Testing for CK19 expression on the excision specimen was negative. Despite being used for a few years now, the OSNAmethod is still relatively new, and updated figures are published regularly. The discrepancy between the OSNA and the imprint cytology results in the case of Vilardell could also be due to tissue allocation bias or due to the false-negative rate of the OSNA method. The latter however is limited to less than 2 % [3]. Moreover, the size of the “malignant cells” on imprint cytology has not been stated suggesting that overinterpretation has not been discounted as a possibility. Our patient’s result may only be representing detection of extremely low-volume disease. It may however be falsely positive. Again, the OSNA false-positivity rate is similarly low, but, importantly, true rates are very difficult to assess. Indeed, as the authors suggest, more documentation is needed to assess the expression of CK19 in breast cancer and its implication on the OSNA results. However, a study to look at the presence or absence of CK19 mRNA, rather than its expression, as detected by immunohistochemistry, may be more appropriate. We suspect that CK19 mRNAnegative tumours will be a small fraction of the CK19negative tumours, which are already rare, and therefore may make routine CK19 testing prior to OSNA processing unnecessary. D. D. Remoundos (*) :M. Joshi : F. Ahmed :G. H. Cunnick Department of Breast Surgery, Wycombe Hospital, Buckinghamshire Healthcare NHS Trust, Queen Alexandra Road, High Wycombe HP11 2TT, UK e-mail: dr223@cantab.net

Clinical application of the one-step nucleic acid amplification method to detect sentinel lymph node metastasis in breast cancer

The one-step nucleic acid amplification (OSNA) method can assess the expression level of cytokeratin 19 mRNA in sentinel lymph nodes in breast cancer. We compared the time required for diagnosis and concordance of results between the OSNA method and conventional intraoperative pathological examination. We then examined the relationship between the frequency of non-sentinel lymph node metastasis and (1) the expression level of CK19 mRNA in the sentinel lymph nodes and (2) clinico-pathological features of the primary tumor. In the comparison study, pairs of sentinel lymph node sections from 53 consecutive patients were examined: one section by hematoxylin-eosin staining and the other by OSNA assay. The latter involved reverse-transcription loop-mediated isothermal amplification of cytokeratin 19 mRNA, assessed quantitatively. In the second phase, 306 sentinel lymph nodes were removed from 248 consecutive patients, and whole sentinel lymph nodes were examined by OSNA assay alone. OSNA assay was a little more time-consuming than conventional pathological diagnosis (34-45 vs. 22-25 min, p < 0.0001). Concordance between the two methods was 93%. The frequency of non-sentinel lymph node metastasis (p < 0.0001) and the total number of lymph node metastases (p < 0.0001) increased with the amount of cytokeratin 19 mRNA on OSNA assay. We found no significant relationship between the amount of cytokeratin 19 mRNA in sentinel lymph nodes and breast cancer immunohistochemical subtype. The OSNA method is suitable to detect sentinel lymph node metastasis and to predict the possibility of non-sentinel metastasis. This semi-automated quantitative analysis system reduces the burden on pathologists.

One-Step Nucleic Acid Amplification (OSNA) Assay for Sentinel Lymph Node Metastases as an Alternative to Conventional Postoperative Histology in Breast Cancer: A Cost-Benefit Analysis

IntroductionIntraoperative molecular analysis for sentinel lymph node (SLN) metastases using the OSNA (one-step nucleic acid amplification) method has been already validated in breast cancer. The authors compared the cost of OSNA versus the conventional postoperative histopathologic evaluation in patients with breast cancer. MethodologyPatients with operable breast cancer and clinically and sonographic negative evaluation of the axilla, and who subsequently were operated on between the 15th of October 2008 and the 15th of December 2009 were included in this retrospective cost-benefit analysis. The SLN was assessed by conventional postoperative histological evaluation in Group 1 (45 patients), and by OSNA in Group 2 (35 patients). The following variables were analysed: age, tumour size, histological type, number of SLNs, biopsy result, duration of surgery, days in hospital, postoperative complications, positive lymph nodes in the case of axillary lymphadectomy, cost per patient, hospitalisation cost, and cost per operation. ResultsThe duration of surgery of the first operation in Group 1 was significantly shorter, but the total time was also higher in this group. The mean hospital stay was longer in Group 1 (P<.001). The mean cost of the hospital stay was higher in Group 1 compared to Group 2 (P<.001), with a mean difference of 199.69€. The mean cost of the surgery was higher in Group 1 (P<.001), with a mean difference of 157.49€. The mean cost per SLN analysis was significantly higher in Group 1, with a mean difference of 162.5€. The cost per patient was significantly higher in Group 1 (P<.005). A mean saving of 439.67€ per patient was achieved by using the OSNA method. ConclusionIntraoperative molecular analysis for SLN metastases using the OSNA method reduces the number of admission days, duration of surgery, and achieves a saving of 439.67€ per patient.

El análisis molecular intraoperatorio (one-step nucleic acid amplification) del ganglio centinela como alternativa al estudio histopatológico diferido en el cáncer de mama: análisis coste-beneficio

Introduction Intraoperative molecular analysis for sentinel lymph node (SLN) metastases using the OSNA (one-step nucleic acid amplification) method has been already validated in breast cancer. The authors compared the cost of OSNA versus the conventional postoperative histopathologic evaluation in patients with breast cancer. Methodology Patients with operable breast cancer and clinically and sonographic negative evaluation of the axilla, and who subsequently were operated on between the 15th of October 2008 and the 15th of December 2009 were included in this retrospective cost-benefit analysis. The SLN was assessed by conventional postoperative histological evaluation in Group 1 (45 patients), and by OSNA in Group 2 (35 patients). The following variables were analysed: age, tumour size, histological type, number of SLNs, biopsy result, duration of surgery, days in hospital, postoperative complications, positive lymph nodes in the case of axillary lymphadectomy, cost per patient, hospitalisation cost, and cost per operation. Results The duration of surgery of the first operation in Group 1 was significantly shorter, but the total time was also higher in this group. The mean hospital stay was longer in Group 1 (P < .001). The mean cost of the hospital stay was higher in Group 1 compared to Group 2 ( P < .001), with a mean difference of 199.69 €. The mean cost of the surgery was higher in Group 1 ( P < .001), with a mean difference of 157.49 €. The mean cost per SLN analysis was significantly higher in Group 1, with a mean difference of 162.5 €. The cost per patient was significantly higher in Group 1 ( P < .005). A mean saving of 439.67 € per patient was achieved by using the OSNA method. Conclusion Intraoperative molecular analysis for SLN metastases using the OSNA method reduces the number of admission days, duration of surgery, and achieves a saving of 439.67 € per patient.

One-Step Nucleic Acid Amplification (OSNA) for the Application of Sentinel Node Concept in Gastric Cancer

This study was designed to apply safely the sentinel node navigation surgery (SNNS) to the malignancies, an accurate and prompt intraoperative diagnosis of SN is essential, and micrometastasis has been frequently missed by conventional frozen sections. Recently, a novel molecular-based rapid diagnosis for the lymph node (LN) metastases has been developed using (OSNA) in breast cancer, which takes approximately 30 min to obtain a final result. We evaluated the efficacy of OSNA in terms of the intraoperative diagnosis of LN metastasis in patients with gastric cancer. A total of 162 LNs dissected from 32 patients with gastric cancer was included in this study; 45 LNs were pathologically diagnosed as metastatic LNs and 117 LNs were negative. The LNs were bisected; halves were examined with H&E stain, and the opposite halves were subjected to OSNA analyses of CK19 mRNA. The CK19 mRNA expression was examined in the positive or negative metastatic LNs, and the correlation between the tumor volume and CK19 mRNA expression in the metastatic LNs was examined. The CK19 mRNA expressions in the positive metastatic LNs were significantly higher than those of negative LNs. When 250 copies/μl was set as a cutoff value, the concordance rate was 94.4%, the sensitivity was 88.9%, and the specificity was 96.6%. The OSNA expression was significantly correlated with the estimated tumor volumes in the metastatic LNs. The OSNA method is feasible and acceptable for detecting LN metastases in patients with gastric cancer. This should be applied for the intraoperative diagnosis in the SN-navigation surgery in gastric cancer.

Abstract P1-01-09: Molecular Detection of Sentinel Lymph Node Metastases in Breast Cancer Patients: Correlation between Cytokeratin 19 mRNA Copy Number Detected by One Step Nucleic Acid Amplification (OSNA) and Risk of Metastases in Axillary Lymph Nodes

Abstract Background: The accuracy of the OSNA assay for metastases detection in sentinel lymph nodes (SLNs) has recently been validated in our Institute and adopted as an intra-operative test for breast cancer (BC) patient management. The aims of this study in a series of early BC patients, were: 1) to correlate the copy numbers of cytokeratin 19 (CK19) mRNA with the size of nodal metastases and with the risk of additional disease in non-sentinel lymph nodes (NSLNs); 2) to investigate the relationship between SLN status with OSNA method, and conventional bio-pathological factors taking into account the molecular BC classification: luminal A, luminal B, HER2 subtype, and triple-negative; 3) to identify a subgroup of patients with positive SLN with higher risk of NSLNs metastatic involvement. Material and Methods: 750 SLNs from 580 patients were clinically processed using both OSNA assay and post-operative histology. The results of these two methods were then compared. The correlation between the size of metastases and the copy numbers of CK19 mRNA was calculated using the Spearman correlation coefficient. Complementary axillary lymph node dissection (ALND) was performed concurrently in case of OSNA assay positivity and the probability of having a positive lymph node axillary dissection was calculated by the unconditional logistic regression model. This series of BC patients were divided into four main subtypes taking in account the BC classification based on the immunohistochemistry phenotypic patterns. Results: OSNA positivity was reported in 24.6% of the patients for a sensitivity of 94.2%. Considering the 145 patients with SLN positivity the size of metastatic foci was significantly correlated to the copy numbers of CK19 mRNA. The complex relationships among the bio-pathological variables analyzed by multiple correspondence analysis (MCA) showed that the metastatic involvement of NSLNs is associated with SLNs with a high copy numbers of CK19 mRNA and HER2 subtype tumors. OSNA specificity (95%) and negative predictive value (98.4%) clearly demonstrated its reliability to guide ALND decision. Conclusions: Our results showed that OSNA is an excellent method for the detection of metastases in SLN and its adoption in our clinical practice has determined a significant improvement in the diagnosis of metastatic BC. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-01-09.