Sentinel Lymph Node Mapping in Lung Cancer: A Pilot Study for the Detection of Micrometastases in Stage I Non-Small Cell Lung Cancer.

Lymphadenectomy represents a fundamental step in the staging and treatment of non-small cell lung cancer (NSCLC). To date, the extension of lymphadenectomy in early-stage NSCLC is a debated topic due to its possible complications. The detection of sentinel lymph nodes (SLNs) is a strategy that can improve the selection of patients in which a more extended lymphadenectomy is necessary. This pilot study aimed to refine lymph nodal staging in early-stage NSCLC patients who underwent robotic lung resection through the application of innovative intraoperative sentinel lymph node (SLN) identification and the pathological evaluation using one-step nucleic acid amplification (OSNA). Clinical N0 NSCLC patients planning to undergo robotic lung resection were selected. The day before surgery, all patients underwent radionuclide computed tomography (CT)-guided marking of the primary lung lesion and subsequently Single Photon Emission Computed Tomography (SPECT) to identify tracer migration and, consequently, the area with higher radioactivity. On the day of surgery, the lymph nodal radioactivity was detected intraoperatively using a gamma camera. SLN was defined as the lymph node with the highest numerical value of radioactivity. The OSNA amplification, detecting the mRNA of CK19, was used for the detection of nodal metastases in the lymph nodes, including SLN. From March to July 2021, a total of 8 patients (3 female; 5 male), with a mean age of 66 years (range 48-77), were enrolled in the study. No complications relating to the CT-guided marking or preoperative SPECT were found. An average of 5.3 lymph nodal stations were examined (range 2-8). N2 positivity was found in 3 out of 8 patients (37.5%). Consequently, pathological examination of lymph nodes with OSNA resulted in three upstages from the clinical IB stage to pathological IIIA stage. Moreover, in 1 patient (18%) with nodal upstaging, a positive node was intraoperatively identified as SLN. Comparing this protocol to the usual practice, no difference was found in terms of the operating time, conversion rate, and complication rate. Our preliminary experience suggests that sentinel lymph node detection, in association with the accurate pathological staging of cN0 patients achieved using OSNA, is safe and effective in the identification of metastasis, which is usually undetected by standard diagnostic methods.

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.

Survival associated with the use of one-step nucleic acid amplification (OSNA) to detect sentinel lymph node metastasis in cervical cancer.

INTRODUCTION: Sentinel lymph node (SLN) biopsy is part of surgical treatment of apparent early-stage cervical cancer. SLN is routinely analyzed by ultrastaging and immunohistochemistry. The aim of this study was to assess the survival of patients undergoing SLN analyzed by one-step nucleic acid amplification (OSNA) compared with ultrastaging. METHODS: Single-center, retrospective, cohort study. Patients undergoing primary surgery and SLN mapping ( ±pelvic lymphadenectomy) for apparent early-stage cervical cancer between May 2017 and January 2021 were included. SLN was analyzed exclusively with OSNA or with ultrastaging. Patients with bilateral SLN mapping failure, with SLN analyzed alternatively/serially with OSNA and ultrastaging, and undergoing neo-adjuvant therapy were excluded. Baseline clinic-pathological differences between the two groups were balanced with propensity-match analysis. RESULTS: One-hundred and fifty-seven patients were included, 50 (31.8%) in the OSNA group and 107 (68.2%) in the ultrastaging group. Median follow up time was 41 months (95%CI:37.9-42.2). 5-year DFS in patients undergoing OSNA versus ultrastaging was 87.0% versus 91.0% (p = 0.809) and 5-year overall survival was 97.9% versus 98.6% (p = 0.631), respectively. No difference in the incidence of lymph node recurrence between the two groups was noted (OSNA 20.0% versus ultrastaging 18.2%, p = 0.931). In the group of negative SLN, no 5-year DFS difference was noted between the two groups (p = 0.692). No 5-year DFS and OS difference was noted after propensity-match analysis (87.6% versus 87.0%, p = 0.726 and 97.4% versus 97.9%, p = 0.998, respectively). CONCLUSION: The use of OSNA as method to exclusively process SLN in cervical cancer was not associated with worse DFS compared to ultrastaging. Incidence of lymph node recurrence in the two groups was not different.

Lymph Node Molecular Analysis with OSNA Enables the Identification of pT1 CRC Patients at Risk of Recurrence: A Multicentre Study.

Early-stage colorectal carcinoma (CRC)-pT1-is a therapeutic challenge and presents some histological features related to lymph node metastasis (LNM). A significant proportion of pT1 CRCs are treated surgically, resulting in a non-negligible surgical-associated mortality rate of 1.5-2%. Among these cases, approximately 6-16% exhibit LNM, but the impact on survival is unclear. Therefore, there is an unmet need to establish an objective and reliable lymph node (LN) staging method to optimise the therapeutic management of pT1 CRC patients and to avoid overtreating or undertreating them. In this multicentre study, 89 patients with pT1 CRC were included. All histological features associated with LNM were evaluated. LNs were assessed using two methods, One-Step Nucleic Acid Amplification (OSNA) and the conventional FFPE plus haematoxylin and eosin (H&E) staining. OSNA is an RT-PCR-based method for amplifying CK19 mRNA. Our aim was to assess the performance of OSNA and H&E in evaluating LNs to identify patients at risk of recurrence and to optimise their clinical management. We observed an 80.9% concordance in LN assessment using the two methods. In 9% of cases, LNs were found to be positive using H&E, and in 24.7% of cases, LNs were found to be positive using OSNA. The OSNA results are provided as the total tumour load (TTL), defined as the total tumour burden present in all the LNs of a surgical specimen. In CRC, a TTL ≥ 6000 CK19 m-RNA copies/µL is associated with poor prognosis. Three patients had TTL > 6000 copies/µL, which was associated with higher tumour budding. The discrepancies observed between the OSNA and H&E results were mostly attributed to tumour allocation bias. We concluded that LN assessment with OSNA enables the identification of pT1 CRC patients at some risk of recurrence and helps to optimise their clinical management.

Evaluation of RASSF1A methylation in the lysate of sentinel lymph nodes for detecting breast cancer metastasis: A diagnostic accuracy study.

The restriction enzyme-based digital methylation-specific polymerase chain reaction (RE-dMSP) assay is useful for diagnosing sentinel lymph node (SN) metastasis in patients with breast cancer, by detecting tumor-derived methylated Ras association domain-containing protein 1 (RASSF1A). In addition, this assay has high concordance (95.0%) with one-step nucleic acid amplification (OSNA). The present study aimed to perform RE-dMSP using OSNA lysate from more patients and to re-evaluate its clinical usage. Overall, 418 SNs from 347 patients were evaluated using both OSNA and RE-dMSP. The concordance rate was 83.3% (348/418). RASSF1A methylation of the primary tumors was negative in 36 patients. When these patients were excluded, the concordance rate improved to 88.2% (330/374). Of the 79 OSNA-negative cases, 19 were RE-dMSP-positive, although all were positive for cytokeratin 19 expression in the primary tumor, suggesting that RE-dMSP can detect tumor-derived DNA with a higher sensitivity. The percent of methylated reference of the breast tumors showed a wide variety in the 16 OSNA-positive/RE-dMSP-negative cases, and such variability of methylation could have affected the results in these patients. In conclusion, although RE-dMSP can diagnose SN metastasis with high sensitivity and accuracy, and can be a supplementary tool to OSNA in breast cancer, RE-dMSP showed certain discordance with OSNA and critically depended on the absence or heterogeneity of DNA methylation in breast tumors. Further research is expected to develop an assay targeting other DNA alterations, such as mutations.

Estudio del ganglio centinela en el cáncer de mama por el método OSNA (One-Step Nucleic Acid Amplification) tras neoadyuvancia en el Hospital Universitario de Navarra / Sentinel lymph node study in breast cancer using the OSNA (one-step nucleic acid amplification) method after neoadjuvant treatment at Hospital Universitario de Navarra

Introducción: la biopsia selectiva de ganglio centinela (GC) es la técnica estándar para la estadificación axilar en el cáncer de mama. No hay consenso en el empleo del método OSNA (One-Step Nucleic Acid Amplification) para el análisis del GC en las pacientes que recibieron el tratamiento neoadyuvante (TNA). En este trabajo analizamos los resultados obtenidos con OSNA en estas pacientes para justificar su implantación en nuestro centro. Material y métodos: se seleccionaron 42 casos del grupo de 163 pacientes con CM tratadas con TNA en nuestro centro, a las que se realizó OSNA del GC, obteniéndose una media de 2,1 ganglios por paciente. Se analizó además la expresión de citoqueratina 19 (CK19), grado tumoral, fenotipo molecular y el grado de respuesta al TNA de estas pacientes. Se estudiaron los GC mediante técnica OSNA y los no centinelas por el método tradicional. Resultados: el grado tumoral fue 2-3 en el 97,6% de los casos, el fenotipo luminal A (17%), luminal B (38%), triple-negativo (26,1%) y HER2 (19%). La respuesta al TNA fue completa en el 59,5% de las pacientes y la expresión de CK19 no se vio modificada. Los ganglios estudiados fueron positivos en 9 pacientes (21,4%) en las que posteriormente se realizó una linfadenectomía y un único caso presentó ganglio no centinela afecto (2,3%). Conclusiones: el método OSNA para el estudio del GC tras el TNA es muy superior al método tradicional, ya que permite la detección intraoperatoria de grupo celular aislado y micrometástasis no detectables con los métodos tradicionales, evitando segundas intervenciones y falsos negativos al analizarse completo el GC, y demuestra que no se altera la expresión de CK19 con el TNA. (AU)

Background: Selective sentinel node (SN) biopsy is the standard technique for axillary staging in breast cancer (BC). There is no consensus on the use of OSNA (One-Step Acid Nucleic Amplification) method for SN in patients undergoing neoadjuvant treatment (NAT). We have studied the results obtained in our centre to justify the advantages of its implementation. Material and methods: 42 cases were selected from the group of 163 patients with BC treated with NAT, who underwent OSNA of the SN, obtaining a mean of 2.1 nodes per patient. We also analyzed cytokeratin 19 (CK19) expression, tumour grade, molecular phenotype and the degree of response to NAT in these patients. The SN were studied using the OSNA technique and non-sentinel nodes using the traditional method. Results: Tumour grade was 2-3 in 97.6% of cases, phenotype luminal A (17%), luminal B (38%), triple-negative (26.1%) and HER2 (19%). The response to NAT was complete in 59.5% of patients and CK19 expression was unchanged. The nodes studied were positive in 9 patients (21.4%) in whom lymphadenectomy was performed and only one case had a non-sentinel node involvement (2.3%). Conclusions: The OSNA method for the study of SN after NAT is far superior to the traditional method as it: It allows intraoperative detection of isolated cell group and micrometastases not detectable with traditional methods, avoiding second interventions. It avoids false negatives when the whole SN is analyzed. It shows that CK19 expression is not altered by NAT. (AU)

Tumour Cell Seeding to Lymph Nodes from In Situ Colorectal Cancer.

Lymph node (LN) metastasis is an important prognostic factor in colorectal cancer (CRC). We aimed to demonstrate the presence of lymphatic vessels (LV) in the mucosa of in-situ (pTis) CRC, and of detectable tumour burden in regional LNs. This is an observational retrospective study of 39 surgically resected in situ CRCs. The number of LVs was evaluated in both pTis and normal mucosa using D2-40 immunostains. All LNs were assessed with both H&E and the One Step Nucleic Acid Amplification (OSNA) assay, and the results were correlated with clinicopathological features. D2-40 immunohistochemisty revealed LVs in the lamina propria of all pTis CRC (100%), being absent in normal mucosa. A median of 16 LNs were freshly dissected per patient, and all cases were pN0 with H&E. Molecular LN analysis with OSNA revealed the presence of low amounts of tumour burden in 11/39 (28%) cases (range 400 to 4270 CK19 mRNA copies/µL), which had no clinical consequences. This study demonstrates the presence of LVs in the lamina propria in 100% of pTis CRC, as well as the presence of low amounts of tumour burden in regional LNs, only detected by molecular methods. Given the prognostic value of LN tumour burden, its molecular quantification may help a patient's clinical management.

Axillary Treatment Management in Breast Cancer during COVID-19 Pandemic (Association between ACOSOG Z0011 Criteria and OSNA Test).

The outbreak of the SARS-COVID-2 pandemic (COVID-19) had a significant effect on the organisation of healthcare systems. Surgical units saw a significant reduction in the volume of surgical procedures performed, with lengthening waiting lists as a consequence. We assessed the surgical activity in relation to breast cancer that took place at the University Hospital of Cagliari, Italy, from February 2018 to March 2022. Two phases were identified based on the epidemiological circumstances: Phase 1-February 2018 to February 2020; Phase 2-March 2020 to March 2022. The surgery performed in the two phases was then compared. All the patients in our sample underwent a breast surgical procedure involving a lymph node biopsy using OSNA associated with the ACOSOG Z0011 criteria. In the study period overall at our facility, there were 4214 procedures, 417 of which involved breast surgery. In Phase 2, 91 procedures were performed using the OSNA method and ACOSOG Z0011 criteria, enabling the intraoperative staging of axillary nodes. Axillary treatment in breast cancer using this approach resulted in a significant reduction in the number of reoperations for the radicalisation of metastatic sentinel lymph nodes.

Cytology Smears: An Enhanced Alternative Method for Colorectal Cancer pN Stage-A Multicentre Study.

Stage II colorectal cancer (CRC) recurrence remains a clinical problem. Some of these patients are true stage III CRC with a pN0 pathology stage. This large prospective multicentre cohort study aimed at evaluating the diagnostic ability of lymph node (LN) cytology smears to perform the pN stage and compare it with the conventional haematoxylin and eosin (H&E) pathology pN stage. Additionally, we used the One-Step Nucleic Acid Amplification (OSNA), a high-sensitive molecular method of LN staging. A total of 3936 fresh LNs from 217 CRC surgical specimens were examined by three methods, H&E, LN cytology smears, and OSNA. H&E detected 29% of patients with positive LNs, cytology smears 35%, and OSNA 33.2% (p < 0.0001). H&E and cytology concordantly classified 92.2% of tumours, and 88.5% between OSNA and H&E. Cytology had 96.8% sensitivity and 90.3% specificity to discriminate positive/negative patients compared to H&E (p = 0.004), and 87.3% sensitivity and 89% specificity when compared to OSNA (p = 0.56). Patients with positive LNs detected by any of the three methods had significantly worse disease-free and overall survival. We conclude that pN stage accuracy for detecting positive LNs is superior with LN cytological smears than with conventional H&E, which would enable a better pN stage and management of early-stage CRC patients.

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.

Total Tumor Load to assist in the decision for additional axillary surgery in the positive sentinel node breast cancer patients.

The Total Tumor Load (TTL) concept has been demonstrated to accurately predict the status of the non-sentinel lymph nodes (NSLN) in breast cancer patients. In 2019, our center implemented the TTL cut-off of 30,000 CK19 mRNA copies/µL as sole criterion for deciding on performing ALND. This retrospective, unicentric, study analyzed 87 cT1-3N0 breast cancer patients treated consecutively in a period of two years and aimed to evaluate the performance of this criterion. Secondary objectives included the comparison of the criterion versus our previous Clinical Decision Rule (CDR) versus ACOSOG Z0011 criteria for avoiding an ALND in proportion of patients spared an ALND and in proportion of patients left with a surgically untreated metastasized axilla. An interim analysis revealed new TTL cut-offs for deciding on performing an ALND. The 30,000 CK19 mRNA copies/µL criterion yielded an area under the ROC Curve (AUC) of 0.849, a false positive (FP) rate of 30.1% and a positive predictive value (PPV) of 38.9%. The 30,000 CK19 mRNA copies/µL criterion spared 58.6% of the patients an ALND versus 41.4% with CDR versus 73.6% with Z0011 and left 0.0% patients with a surgically untreated metastasized axilla versus 21.4% with CDR versus 42.9% with Z0011. The new TTL cut-off of 260,000 CK19 mRNA copies/µL for deciding on an ALND yielded an AUC of 0.753, a FP rate of 13.7% and a PPV of 47.4%. This new criterion spared 78.2% of the study sample an ALND and left 35.7% of metastasized axillae surgically untreated. This study emphasizes the need to find a new balance between locoregional control and the morbidity associated with Berg levels I + II axillary lymph node dissection.

OPTimizing Irradiation through Molecular Assessment of Lymph node (OPTIMAL): a randomized clinical trial.

BACKGROUND AND PURPOSE: In breast cancer (BC) patients, the involvement of four or more lymph nodes (LN) is an indication of regional irradiation. The optimal treatment strategy remains unclear when fewer nodes are involved and lymphadenectomy is not performed. We designed a clinical trial to show the non-inferiority of Incidental (INC) compared to intentional (INT) irradiation of axillary nodes in patients with early-stage BC and low burden LN involvement. MATERIALS AND METHODS: BC patients, cN0 (n = 487) undergoing breast conservation surgery and sentinel node biopsy, with total tumor load assessed by OSNA (One-Step Nucleic Acid Amplification) of 250-15,000 copies mRNA CK19/µL in sentinel LN were randomized to receive INC or INT nodal irradiation. The primary endpoint was 5-year disease-free survival (DFS). Secondary endpoints were locoregional recurrence (LRR), distant recurrence (DR), and acute and chronic toxicity (CT). RESULTS: Five-years DFS were 93.7% (INC) and 93.8% (INT) (difference 0.1% [one-sided 95% CI < 5.7%]; non-inferiority p = 0.075). Cumulative Incidences of LRR were 3.5% (INC) and 3.4% (INT) (difference of 0.1% [<4.8%]; p = 0.021), and 5% (INC) and 3.5% (INT) (difference 1.4% [<6.0%]; non-inferiority p = 0.101) for DR. CT was more Incident with INT (26.9%) than with INC (19.2%), though the difference was not statistically significant (HR 1.39 [95% CI: 0.92, 2.10]; p = 0.11). CONCLUSION: Intentional does not outperform incidental irradiation by more than 5.7% in terms of 5-year DFS, 4.8% for LRR, and 6% for DR. REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT02335957.

Can clinicopathological factors improve the prediction of metastasis to nonsentinel lymph nodes in patients with breast cancer?

INTRODUCTION: To determine whether clinicopathological characteristics can improve the prediction of metastasis to nonsentinel lymph nodes (NSLNs) over the use of only mRNA copy number in sentinel lymph node (SLN) biopsies. METHODS: This was a retrospective, observational study that included a total of 824 patients with T1-3 breast cancer who had clinically negative, ultrasound-negative axilla without evidence of metastasis and who underwent one-step nucleic acid amplification in SLN biopsies. RESULTS: 118 required a complete axillary lymph node dissection (ALNhD). About 35.6% (42/118) had metastases to a NSLN, and 64.4% (76/118) had no metastasis to a NSLN. The ROC curve of the total tumor load (TTL) presented an area under the curve (AUC) of 0.651 (95%; CI: 0.552-0.751). The 7294 copies of CK19 mRNA were established as the optimal cutoff point, with sensitivity: 93%, specificity: 63%, positive predictive value: 44%, and negative predictive value: 91%. By associating the clinicopathological parameters (multicentricity, pooled immunohistochemistry [IHC], and progesterone receptors), the AUC went up to 0.752 (95% CI: 0.663-0.841). CONCLUSIONS: Clinicopathological factors should be considered together with the total CK19 mRNA copy number (the TTL) of the SLNs to improve the predictive capacity of metastatic involvement of the NSLNs.

INTRODUCCIÓN: Nuestro objetivo era determinar si la influencia de las características clínicopatológicas pueden mejorar la predicción de metástasis en los ganglios linfáticos no centinelas (GLNC) a partir de un punto de corte de copias de ARNm determinado en la biopsia del ganglio linfático centinela (GLC). MÉTODOS: Se realizó un estudio observacional retrospectivo incluyendo a un total de 824 pacientes con cáncer de mama T1-3, con axila clínica y ecográficamente negativa para metástasis en los ganglios axilares. Se les practicó una biopsia selectiva del GLC y estudio posterior mediante el método one step nucleic acid amplification (OSNA). RESULTADOS: 118 precisaron una disección completa de los ganglios linfáticos axilares. 35,6% (42/118) tuvieron metástasis en GLNC y 64.4% (76/118) no presentaron metástasis en GLNC. La curva ROC del log de la carga tumoral total (CTT) presentó un área bajo la curva de 0.651 (95%; IC: 0.552-0.751). Se estableció las 7294 copias de ARNm de CK19 como punto de corte óptimo, con sensibilidad: 93%, especificidad: 63%, valor predictivo positivo: 44% y valor predictivo negativo: 91%. Al asociar los parámetros clinicopatológicos (multicentricidad, inmunohistoquímica (IHQ) agrupado y receptores de progesterona) obtenemos un área bajo la curva mejorada de 0.752 (95% intervalo de confianza [IC] 0.663-0.841). CONCLUSIONES: Los factores clinicopatológicos deberían valorarse asociados al corte de copias de ARNm de la CTT de CK19 de los GLCs para mejorar la capacidad predictiva de afectación metastásica en los GLNCs.

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.

Update on sentinel node pathology in breast cancer.

Pathologic examination of the sentinel lymph nodes (SLNs) in patients with breast cancer has been impacted by the publication of practicing changing trials over the last decade. With evidence from the ACOSOG Z0011 trial to suggest that there is no significant benefit to axillary lymph node dissection (ALND) in early-stage breast cancer patients with up to 2 positive SLNs, the rate of ALND, and in turn, intraoperative evaluation of SLNs has significantly decreased. It is of limited clinical significance to pursue multiple levels and cytokeratin immunohistochemistry to detect occult small metastases, such as isolated tumor cells and micrometastases, in this setting. Patients treated with neoadjuvant therapy, who represent a population with more extensive disease and aggressive tumor biology, were not included in Z0011 and similar trials, and thus, the evidence cannot be extrapolated to them. Recent trials have supported the safety and accuracy of sentinel lymph node biopsy (SLNB) in these patients when clinically node negative at the time of surgery. ALND remains the standard of care for any amount of residual disease in the SLNs and intraoperative evaluation of SLNs is still of value for real time surgical decision making. Given the potential prognostic significance of residual small metastases in treated lymph nodes, as well as the decreased false negative rate with the use of cytokeratin immunohistochemistry (IHC), it may be reasonable to maintain a low threshold for the use of cytokeratin IHC in post-neoadjuvant cases. Further recommendations for patients treated with neoadjuvant therapy await outcomes data from ongoing clinical trials. This review will provide an evidence-based discussion of best practices in SLN evaluation.

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 Summary: Implementing 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. Background: The 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). Methods: In 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. Results: We 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%). Conclusions: No difference in OS and DFS was found comparing OSNA, FS, and definitive histology. Furthermore, reduced operative time was found in the OSNA group.

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.

Cytokeratin Expression Pattern in Human Endometrial Carcinomas and Lymph Nodes Micrometastasis: a Mini-review.

Cytokeratins (CKs) are the largest subgroup of intermediate filament proteins, preferentially expressed in epithelial tissues. CKs play a critical role in determining epithelial structural integrity under stressful conditions in addition to their various fundamental functions in cellular proliferation, apoptosis, migration, adherence and molecular signaling. Immunohistochemical CKs staining could be evaluated with a proper comprehension of their task limitations and their association with the normal morphology to avoid misdiagnosis. Herein, we critically review the CKs expression patterns in ECs in relation to clinicopathological features and patients' outcome. We also briefly discussed the recent advantage of CKs immunohistochemical staining in the detection of EC micrometastasis.

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.

BACKGROUND: The 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. METHODS: SN 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. RESULTS: The 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. CONCLUSIONS: Using 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.