Intra-operative assessment of sentinel lymph node status by one-step nucleic acid amplification assay (OSNA) in early endometrial cancer: a prospective study

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

OBJECTIVE

To 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 with standard ultrastaging.

METHODS

Prospective, multicentric, interventional study. Patients with apparent early-stage endometrial cancer who underwent primary surgical staging with SLN mapping were included. SLNs were serially sectioned with 2 mm slices perpendicular to the longest axis of the node: the odd slices were submitted to ultrastaging, whereas the even slices were submitted to the OSNA analysis. Diagnostic performance was calculated taking ultrastaging as referral standard.

RESULTS

Three-hundred and sixteen patients with 668 SLNs were included. OSNA assay detected 22 (3.3%) positive SLNs, of which 17 (2.5%) were micrometastases and 5 (0.7%) macrometastases, whereas ultrastaging detected 24 (3.6%) positive SLNs, of which 15 (2.2%) were micrometastases and 9 (1.3%) macrometastases (p=0.48). Regarding negative SLNs, OSNA detected 646 (96.7%) negative nodes, including 8 (1.2%) isolated tumor cells, while ultrastaging detected 644 (96.4%) negative nodes with 26 (3.9%) isolated tumor cells. Specificity of OSNA was 98.4% (95% CI 97.5 to 99.4), accuracy was 96.7% (95% CI 95.4 to 98.1), sensitivity was 50% (95% CI 30.0 to 70.0), while negative predictive value was 98.1% (95% CI 97.1 to 99.2). Discordant results were found in 22 SLNs (3.3%) corresponding to 20 patients (6.3%). These were 10 (1.5%) false-positive SLNs (all micrometastases): one (0.1%) of these was a benign epithelial inclusion at ultrastaging. There were 12 (1.8%) false-negative SLNs of OSNA, of which 9 (1.3%) were micrometastases and 3 (0.5%) macrometastases. Overall, 17/668 (2.5%) benign epithelial inclusions were detected at ultrastaging.

CONCLUSION

The OSNA method had high specificity and high accuracy in detecting SLN metastasis in apparent early-stage endometrial cancer. The advantage of the OSNA method could be represented as the possibility to analyze the entire lymph node thus eliminating sampling bias.

Laparoscopic and Laparotomic Restaging in Patients With Apparent Stage I Epithelial Ovarian Cancer: A Comparison of Surgical and Oncological Outcomes

Objective

To assess the surgical and oncological outcomes of laparoscopic restaging compared with laparotomy for apparent early-stage epithelial ovarian cancer.

Methods

A retrospective chart review was undertaken of patients who underwent laparoscopic (laparoscopy group) or laparotomic (laparotomy group) restaging at the Peking Union Medical College Hospital, China, between January 2012 and December 2017. All patients had apparent stage I epithelial ovarian cancer that was incompletely staged at the initial surgery.

Results

A total of 157 patients were included, with 50 in the laparoscopy group and 107 in the laparotomy group. Baseline characteristics were similar between the groups. No cases were converted from laparoscopy to laparotomy. The laparoscopy group had a significantly shorter operating time (p<0.001), less estimated blood loss (p<0.001), and a shorter postoperative hospitalization duration (p<0.001) than the laparotomy group. Transfusions were required in only eight laparotomy patients. No significant differences in postoperative complications were observed between the two groups (p=0.55). Eighteen (11.5%) patients were upstaged to stage II or stage III after surgery. A total of 123 (78.3%) patients received postoperative platinum-based chemotherapy. During the follow-up period, 15 (9.6%) patients experienced disease recurrence, and 3 patients died of disease progression. Five-year disease-free survival (p = 0.242, log-rank test) and overall survival (p = 0.236, log-rank test) were not affected by the surgical approach.

Conclusions

Laparoscopic restaging showed more favorable operative outcomes than laparotomy. Surgical restaging via laparoscopy versus laparotomy was not associated with worse survival in women with apparent stage I epithelial ovarian cancer.

Clinical issues of surgery for uterine endometrial cancer in Japan

OBJECTIVE

The mainstay of treatment for uterine endometrial cancer is surgery, and recurrent-risk cases require multidisciplinary treatment, including surgery, chemotherapy and radiation therapy.

METHODS

The standard surgery for uterine endometrial cancer is hysterectomy and bilateral salpingooophorectomy, with additional retroperitoneal lymph node dissection and omentectomy, depending on the case. The appropriate treatment is determined based on the risk classification, such as the depth of invasion into the myometrium, diagnosis of histological type and grade, and risk assessment of lymph node metastasis.

RESULTS

Recently, minimally invasive surgery has been widely used not only in low-risk patients but also in intermediate- and high-risk patients. In low-risk patients, the possibility of ovarian preservation is discussed from a healthcare perspective for young women. Determining the need for retroperitoneal lymph node dissection based on sentinel lymph node evaluation may contribute in minimizing the incidence of post-operative lymphedema while ensuring accurate diagnosis of lymph node metastasis. Recently, many studies using sentinel lymph nodes have been reported for patients with uterine endometrial cancer, and the feasibility of sentinel lymph node mapping surgery has been proven. Unfortunately, sentinel lymph node biopsy and sentinel lymph node mapping surgery have not been widely adopted in surgery for uterine cancer in Japan. In addition, the search for biomarkers, such as RNA sequencing using The Cancer Genome Atlas, metabolic profile and lipidomic profile for early detection and prognostic evaluation, has been actively pursued.

CONCLUSIONS

Gynecologic oncologists expect to be able to provide uterine endometrial cancer patients with appropriate treatment that preserves their quality of life without compromising oncologic outcomes in the near future.

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

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.

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

Sentinel lymph node (SLN) biopsy has emerged as an alternative staging approach in women with assumed early-stage endometrial carcinoma. Through image-guided surgery and pathologic ultrastaging, the SLN approach is introducing “precision medicine” to the surgical management of gynecologic cancers, providing a comprehensive evaluation of high-yield lymph nodes. This approach improves the surgeons’ ability to detect small-volume metastatic disease while reducing intraoperative and postoperative morbidity associated with lymphadenectomy. Although the majority of clinicians in Europe and the USA have recognized the value of SLN biopsy in endometrial carcinoma and introduced this as part of clinical practice, there is ongoing debate regarding its role in very low-risk patients as well as in patients at high risk of nodal metastasis. The significance of low-volume metastasis is not fully understood, and there is no consensus in regard to how the presence of isolated tumor cells should guide adjuvant therapy. Standardized protocols for histopathologic evaluation of SLNs are lacking. In this review article we aim to provide a framework for the introduction of SLN biopsy in endometrial cancer, give an updated overview of the existing literature, as well as discuss potential controversies and unanswered questions regarding this approach and future directions.

Sentinel Lymph Node Mapping in Endometrial Cancer: A Comprehensive Review

Endometrial cancer (EC) is known as a common gynecological malignancy. The incidence rate is on the increase annually. Lymph node status plays a crucial role in evaluating the prognosis and selecting adjuvant therapy. Currently, the patients with high-risk (not comply with any of the following: (1) well-differentiated or moderately differentiated, pathological grade G1 or G2; (2) myometrial invasion< 1/2; (3) tumor diameter < 2 cm are commonly recommended for a systematic lymphadenectomy (LAD). However, conventional LAD shows high complication incidence and uncertain survival benefits. Sentinel lymph node (SLN) refers to the first lymph node that is passed by the lymphatic metastasis of the primary malignant tumor through the regional lymphatic drainage pathway and can indicate the involvement of lymph nodes across the drainage area. Mounting evidence has demonstrated a high detection rate (DR), sensitivity, and negative predictive value (NPV) in patients with early-stage lower risk EC using sentinel lymph node mapping (SLNM) with pathologic ultra-staging. Meanwhile, SLNM did not compromise the patient’s progression-free survival (PFS) and overall survival (OS) with low operative complications. However, the application of SLNM in early-stage high-risk EC patients remains controversial. As revealed by the recent studies, SLNM may also be feasible, effective, and safe in high-risk patients. This review aims at making a systematic description of the progress made in the application of SLNM in the treatment of EC and the relevant controversies, including the application of SLNM in high-risk patients.

Sentinel lymph node detection in endometrial cancer with indocyanine green: laparoscopic versus robotic approach

BACKGROUND

The aims of the present study were to assess bilateral sentinel lymph node (SLN) mapping with laparoscopic versus robotic approach, to assess variables affecting bilateral detection rates and to assess survival difference in patients with no/unilateral, compared to bilateral SLN detection.

METHODS

This is a retrospective, single-centre, observational cohort study, including patients with endometrial cancer FIGO stage IA-IVB, treated with minimally invasive primary surgery and undergoing indocyanine green (ICG) injection to detect SLN, between January 2015 and December 2019.

RESULTS

Of the 549 included patients, 286 (52.1%) and 263 (47.9%) underwent the laparoscopic and robotic approach respectively. 387 (70.5%) patients had bilateral SLN mapping, 102 (18.6%) and 60 (10.9%) had unilateral and no mapping, respectively. Patients who underwent the robotic approach were older (median 61 versus 64 years, p=0.046) and had a higher BMI (median 26.0 versus 34.8 kg/m2, p<0.001). No difference in any SLN mapping or in SLN bilateral detection was evident between the laparoscopic or robotic approach (p=0.892 and p=0.507 respectively). Patients with bilateral SLN detection in the entire cohort were younger (p<0.001) and had a better 3-year disease-free survival (DFS) compared to patients with no/unilateral SLN mapping (77.0% versus 66.3%, respectively, p=0.036). No 3-year overall survival (OS) difference was reported (p=0.491).

CONCLUSION

SLN mapping and bilateral SLN detection with ICG in endometrial cancer was not different in the laparoscopic and robotic approach, even though patients undergoing the robotic approach were older and more obese. Bilateral SLN detection was associated with improved 3-year DFS, but not with 3-year OS, compared to no and unilateral SLN detection.

Can risk groups accurately predict non-sentinel lymph node metastasis in sentinel lymph node-positive endometrial cancer patients? A Turkish Gynecologic Oncology Group Study (TRSGO-SLN-004)

BACKGROUND AND OBJECTIVES

The purpose of this study was to find out the risk factors associated with non-sentinel lymph node metastasis and determine the incidence of non-sentinel lymph node metastasis according to risk groups in sentinel lymph node (SLN)-positive endometrial cancer patients.

METHODS

Patients who underwent at least bilateral pelvic lymphadenectomy after SLN mapping were retrospectively analyzed. Patients were categorized into low, intermediate, high-intermediate, and high-risk groups defined by ESMO-ESGO-ESTRO.

RESULTS

Out of 395 eligible patients, 42 patients had SLN metastasis and 16 (38.1%) of them also had non-SLN metastasis. Size of SLN metastasis was the only factor associated with non-SLN metastasis (p = .012) as 13/22 patients with macrometastasis, 2/10 with micrometastasis and 1/10 with isolated tumor cells (ITCs) had non-SLN metastasis. Although all 4 metastases (1.8%) among the low-risk group were limited to SLNs, the non-SLN involvement rate in the high-risk group was 42.9% and all of these were seen in patients with macrometastatic SLNs.

CONCLUSIONS

Non-SLN metastasis was more frequent in higher-risk groups and the risk of non-SLN metastasis increased with the size of SLN metastasis. Proceeding to complete lymphadenectomy when SLN is metastatic should further be studied as the effect of leaving metastatic non-SLNs in-situ is not known.

Sentinel lymph node intraoperative analysis in endometrial cancer

PURPOSE

Surgical staging in endometrial cancer has evolved and sentinel lymph node (SLN) mapping has replaced a full pelvic and paraaortic lymphadenectomy in several cases. An intraoperative evaluation of SLN might identify patients who could benefit the most from a full lymphadenectomy. The aim of this study is to evaluate the clinical relevance of frozen section of SLN.

METHODS

A retrospective analysis in patients with endometrial cancer who underwent SLN mapping with intraoperative evaluation at frozen section between February 2016 and September 2019 was performed. In case of metastatic involvement, a full lymphadenectomy was performed.

RESULTS

Fifty-eight patients met the inclusion criteria. Clinical-pathologic characteristics of the patients and surgical data were analyzed. Overall, bilateral and unilateral detection rates were 100% (58/58), 89.7% (52/58), and 10.3% (6/58), respectively. Eight patients had a stage IIIC disease at permanent section. Frozen section detected SLN metastases in four of eight patients. Of these, two were micrometastases and two were macrometastases. At frozen section of the SLNs, no macrometastases were misdiagnosed. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value of frozen section in detecting metastases was 50%, 100%, 93%, 100% and 92.6%, respectively.

CONCLUSION

The intraoperative evaluation of SLN in endometrial cancer accurately identifies patients with macrometastases. This is the cohort that might benefit the most of a full lymphadenectomy for a higher risk of additional lymph node metastases.

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

INTRODUCTION

The 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.

METHODS

All 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.

RESULTS

Of 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).

CONCLUSIONS

The 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.