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

Abstract

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.

Sentinel Lymph Node Mapping in Endometrial Cancer: A Comprehensive Review

“…It is a molecular-based method for the detection of metastatic lymph nodes in breast cancer or colorectal cancer patients using CK19 as a single marker. Mounting evidence has demonstrated good sensitivity and specificity of OSNA in identifying positive nodes, especially micro-metastasis, in endometrial cancer (147)(148)(149)(150). Compared with ultra-staging, OSNA is much faster thus can be done intraoperatively; moreover, it identified more SLN involvement, resulting in 20.69% of patients upstaged as FIGO stage III (150).…”

Spatially resolved proteomics identify biomarkers from endometrial sentinel lymph nodes

“…Currently, the majority of investigations of molecular biomarkers of endometrial cancer SLNs are limited to a one-step nucleic acid amplification (OSNA) assay to detect known cancer-related proteins, such as CK19. 4 The current investigation provides the first global proteomic view of endometrial cancer SLNs and validates their clinical significance. In addition, the authors have applied a pioneering technology, termed “spatially resolved proteomics,” to globally characterize the proteome of endometrial cancer SLNs with different pathological grades.…”

Update on Sentinel Lymph Node Biopsy in Surgical Staging of Endometrial Carcinoma

“…There is considerable variation between institutions with respect to the number of sections examined by routine Hematoxylin and Eosin (H&E) staining, depth of sectioning into tissue blocks, the interval of microns between parallel sections and the use of immunohistochemistry (IHC) to identify tumor cells not noted on H&E stain alone [ 43 ]. Some centers have adopted one-step nucleic acid amplification (OSNA) in evaluation of SLNs and showed that patients with metastatic non-SLNs had macrometastasis in the positive SLNs as defined by OSNA [ 44 , 45 ]. OSNA could potentially replace intraoperative frozen section of SLNs in cases where the status of metastatic vs. non-metastatic SLN would influence intraoperative management.…”