One-Step Nucleic Acid Amplification (OSNA): A fast molecular test based on CK19 mRNA concentration for assessment of lymph-nodes metastases in early stage endometrial cancer

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. 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 analysed 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.

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

Cancers ◽

10.3390/cancers13174465 ◽

2021 ◽

Vol 13 (17) ◽

pp. 4465

Author(s):

María Dolores Diestro ◽

Alberto Berjón ◽

Ignacio Zapardiel ◽

Laura Yébenes ◽

Irune Ruiz ◽

...

Keyword(s):

Endometrial Cancer ◽

Lymph Node ◽

Nucleic Acid ◽

Sentinel Lymph Node ◽

Early Stage ◽

Nucleic Acid Amplification ◽

One Step ◽

Hematoxylin Eosin ◽

Early Stage Endometrial Cancer ◽

Osna Assay

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.

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

International Journal of Gynecological Cancer ◽

10.1136/ijgc-2019-000937 ◽

2020 ◽

Vol 30 (3) ◽

pp. 372-377 ◽

Cited By ~ 3

Author(s):

Francesco Fanfani ◽

Giorgia Monterossi ◽

Maria Letizia Di Meo ◽

Eleonora La Fera ◽

Federica Dell'Orto ◽

...

Keyword(s):

Endometrial Cancer ◽

Lymph Node ◽

Nucleic Acid ◽

Sentinel Lymph Node ◽

Early Stage ◽

Negative Control ◽

Nucleic Acid Amplification ◽

Prognostic Impact ◽

Control Slide ◽

One Step

IntroductionThe objective of this study was to compared standard ultra-staging (SU) with one-step nucleic acid amplification (OSNA) for the detection of sentinel lymph node (SLN) metastasis in women with apparent uterine-confined endometrial cancer.MethodsAll women underwent SLN identification with complete surgical staging. All SLNs were cut perpendicular to the long axis and two adjacent 5 µm sections were cut at each of two levels 50 µm apart. At each level, one slide was stained with hematoxylin and eosin and the other with immunohistochemistry using the AE1/AE3 anti-cytokeratin antibody, as well as one negative control slide for a total of five slides per block. For OSNA analysis, the 2 mm sections of the lymph nodes were homogenized to form a lysate. The lysate was then centrifuged and inserted into the RD 100i instrument where the isothermal amplification of CK19 mRNA was executed.ResultsOf the 396 patients included in the retrospective analysis, 214 were in the SU group, and 182 in the OSNA group. Overall 869 SLNs were identified (490 SU, 379 OSNA). Sixty patients exhibited SLN metastasis (34 SU, 26 OSNA). Macrometastasis, micrometastases, and isolated tumor cells (ITC) were 5.1%, 4.1%, and 0.2%, respectively, in the US group, and 2.4%, 6.3%, and 0.1%, respectively, in the OSNA group (p=0.022).ConclusionsThe OSNA assay detected a higher rate of micrometastasis and a lower rate of macrometastasis and ITC when compared with SU. The clinical and prognostic impact of ITC is debatable and controversial. Further studies are needed to clarify the respective roles of the OSNA and SU methods, and the possible role of ITC in the prognosis of patients with apparent early-stage endometrial cancer.

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