The Incidence and Clinical Significance of the Micrometastases in the Sentinel Lymph Nodes During Surgical Staging for Early Endometrial Cancer

Establishing guidelines for sentinel lymph node ultrastaging in endometrial cancer

BACKGROUND

Many sentinel lymph node (SLN) ultrastaging protocols for endometrial cancer exist, but there is no consensus method.

OBJECTIVE

This study aims to develop guidelines for size criteria in SLN evaluation for endometrial cancer, to determine whether a single cytokeratin AE1:AE3 immunohistochemical slide provides sufficient data for diagnosis, and to compare cost efficiency between current and limited ultrastaging protocols at a large tertiary care institution.

METHODS

Our current SLN ultrastaging protocol consists of cutting two adjacent paraffin block sections at two levels (L1 and L2), 50 μm apart, with two slides at each level stained with hematoxylin and eosin and cytokeratin AE1:AE3 immunohistochemistry. We retrospectively reviewed digitized L1 and L2 slides of all positive ultrastaged SLNs from patients treated for endometrial cancer between January 2013 and January 2020. SLN diagnosis was defined by measuring the largest cluster of contiguous tumor cells in a single cross section: macrometastasis (>2.0 mm), micrometastasis (>0.2 to ≤2.0 mm or >200 cells), or isolated tumor cells (≤0.2 mm or ≤200 cells). Concordance between L1 and L2 results was evaluated. Cost efficiency between current (two immunohistochemical slides per block) and proposed limited (one immunohistochemical slide per block) protocols was compared.

RESULTS

Digitized slides of 147 positive SLNs from 109 patients were reviewed; 4.1% of SLNs were reclassified based on refined size criteria. Complete concordance between L1 and L2 interpretations was seen in 91.8% of SLNs. A false-negative rate of 0%-0.9% in detecting micrometastasis and macrometastasis using a limited protocol was observed. Estimated charge-level savings of a limited protocol were 50% per patient.

CONCLUSION

High diagnostic accuracy in SLN interpretation may be achieved using a limited ultrastaging protocol of one immunohistochemical slide per block and linear measurement of the largest cluster of contiguous tumor cells. Implementation of the proposed limited ultrastaging protocol may result in laboratory cost savings with minimal impact on health outcomes.

Prognostic value of lymph node features in patients diagnosed with stage IIIC endometrial adenocancer

AIM

Our study investigated the lymph node (LN) features most affecting survival in endometrial adenocancer (EAC) patients with LN involvement.

MATERIALS AND METHODS

This retrospective study was based on a review of the records of patients diagnosed with EAC, who underwent hysterectomy and systematic retroperitoneal lymphadenectomy at the gynecologic oncology clinics of three centers between January 2009 and January 2019.

RESULTS

A total of 120 stage IIIC endometrioid-type EAC patients were included in the study. The patients were divided into small (<10 mm) and large (≥10 mm) groups according to the size of the largest metastatic LN. Patients were divided into single and multiple metastasis groups according to the number of metastatic LNs. The patients were divided into pelvic and paraaortic groups according to the location of the metastatic LNs. The effects of prognostic factors on disease-free survival (DFS) and overall survival (OS) were evaluated by Cox regression analysis. Large-sized metastatic LNs were an independent prognostic factor for DFS (hazard ratio [HR] = 5.4, 95% confidence interval [CI]: 1.-26.2; P = 0.035) and OS (HR = 9.0, 95% CI: 1.1-68.0; P = 0.033). The number (P = 0.093 for DFS, P = 0.911 for OS) and location (P = 0.217 for DFS, P = 0.124 for OS) of metastatic LNs were not independent prognostic factors for DFS or OS.

CONCLUSIONS

Large-sized metastatic LNs were an independent prognostic factor for survival in patients with stage IIIC EAC. Larger prospective studies including similar patient populations are required to verify these findings.

Blue dye single labelling for colorimetric sentinel lymph node mapping in early endometrial cancer: A feasibility study

Background

Surgical staging in endometrial cancer includes a systematic lymphadenectomy with significant morbidity, although its therapeutic role is unclear. Sentinel lymph node (SLN) study is a less morbid alternative to identify nodes most likely to be metastatic, permitting selective removal and thus reducing morbidity without compromising oncological safety. This study was done using blue dye single labelling to study the feasibility and utility in identifying SLN in early disease.

Methods

Twenty-two patients of early-stage low-risk disease during surgical staging underwent cervical injection of methylene blue, SLN mapping, and sampling as per the standard algorithm, followed by a systematic lymphadenectomy in all cases. SLN were submitted separately for ultrastaging (US).

Results

Twenty patients underwent the procedure, and SLN could be identified in 18 patients with an overall mapping rate of 90% with a bilateral mapping rate of 70%, and a negative mapping rate of 10%. 57 SLN were identified along with two suspicious non-sentinel nodes and 11 were metastatic on US with a sensitivity of 66.7% and NPV of 87.5%. All patients with metastatic nodes, however, could be identified by applying the standard SLN algorithm for sampling.

Conclusion

SLN mapping algorithm with blue dye single labelling in early endometrial cancer, by identifying LN most likely to be metastatic enabling their selective removal may help avoid routine lymphadenectomies without compromising oncological safety. The procedure is simple and can be practiced at all centres and can also aid pathologists by pinpointing the likely metastatic nodes after a selective or complete lymphadenectomy.

Association between sentinel lymph node biopsy and micrometastasis in endometrial cancer

OBJECTIVE

Sentinel lymph node (SLN) biopsy is increasingly utilized at surgical staging for early endometrial cancer. This study examined the association between SLN biopsy and micrometastasis in endometrial cancer.

METHODS

This is a retrospective cohort study examining the National Cancer Institute's Surveillance, Epidemiology, and End Result Program. The study population was 6,414 women with T1-2 endometrial cancer who underwent primary hysterectomy and surgical nodal evaluation. Exclusion criteria included cases with isolated tumor cells. Exposure assignment was surgical nodal evaluation (SLN biopsy or lymphadenectomy). Main outcome measure was micrometastasis, assessed by inverse probability of treatment weighting propensity score in a stage-specific fashion.

RESULTS

In T1a disease (n = 4,608), SLN biopsy was performed in 1,164 (25.3%) cases. SLN biopsy was associated with a 90% increased likeliness of identifying micrometastasis compared to lymphadenectomy (1.3% versus 0.7%, odds ratio 1.90, 95% confidence interval 1.02-3.55, P = 0.040). In T1b disease (n = 1,369), 270 (19.7%) cases had SLN biopsy. The incidence of micrometastasis was significantly higher in the SLN biopsy group compared to the lymphadenectomy group (8.4% versus 5.0%, odds ratio 1.74, 95% confidence interval 1.06-2.86, P = 0.028). In T2 disease (SLN biopsy in 57 [13.0%] of 437 cases), the incidence of micrometastasis was similar between the two groups (7.9% versus 7.0%, odds ratio 0.88, 95% confidence interval 0.30-2.60, P = 0.818).

CONCLUSION

This study suggests that SLN biopsy protocol may identify more micrometastasis in the regional lymph nodes of T1 endometrial cancer. Whether national-level increase in the utilization of SLN biopsy for early endometrial cancer results in a stage-shifting to advanced disease on a population-basis warrants further investigation.

Ultrastaging methods of sentinel lymph nodes in endometrial cancer - a systematic review

OBJECTIVE

Sentinel lymph node mapping has emerged as an alternative to lymphadenectomy in evaluating the lymph node status in endometrial cancer. Several pathological methods to examine the sentinel lymph node are applied internationally. The aim of this study was to determine the value of ultrastaging and to assess the ultrastaging method with the highest detection rate of metastases.

METHODS

A systematic review was conducted. Inclusion criteria were: pathologically-confirmed endometrial cancer with sentinel lymph node mapping, report of the histological outcomes, metastases found by hematoxylin and eosin staining and metastases found by ultrastaging were separately mentioned, and description of the ultrastaging method. The primary outcome was the detection of metastases found by ultrastaging that were not detected by routine hematoxylin and eosin staining. The secondary outcome was the difference in detection rate of metastases between several ultrastaging methods. Random effects meta-analyses were conducted.

RESULTS

Fifteen studies were selected, including 2259 patients. Sentinel lymph nodes were examined by routine hematoxylin and eosin staining. Subsequently, multiple ultrastaging methods were used, with differences in macroscopic slicing (bread-loaf/longitudinal), number of microscopic slides, and distance between slides, but all used immunohistochemistry. A positive sentinel lymph node was found in 14% of patients. In 37% of these, this was detected only by ultrastaging. Using more ultrastaging slides did not result in a higher detection rate. Bread-loaf slicing led to a higher detection rate compared with longitudinal slicing (mean detection rates 53% and 33%, respectively).

CONCLUSION

Pathological ultrastaging after routine hematoxylin and eosin staining in endometrial cancer patients has led to an increased detection rate of sentinel lymph node metastases. Different ultrastaging methods are used, with a preference for bread-loaf slicing. However, due to the large heterogeneity of the studies, assessing which ultrastaging method has the highest detection rate of sentinel lymph node metastases was not possible.

Sentinel Lymph Nodes in Endometrial Cancer Update 2018

There are no established data about lymphadenectomy during treatment of endometrial cancers (ECs) and to what extent lymphadenectomy should be performed. In addition, retroperitoneal lymphadenectomy increases the intraoperative and postoperative complications. Sentinel lymph node (SLN) mapping has the lowest costs and highest quality-adjusted survival. SLN is the most cost-effective strategy in the management of low-risk ECs. Women staged with SLN mapping were more likely to receive adjuvant treatment compared with women staged with systemic lymphadenectomy. This review article designed to evaluate the diagnostic accuracy and the methods of SLN detection in ECs.

[S3 guidelines on the diagnosis and treatment of carcinoma of the endometrium : Requirements for pathology]

The present article summarises the relevant aspects of the S3 guidelines on endometrioid carcinomas. The recommendations include the processing rules of fractional currettings as well as for hysterectomy specimens and lymph node resections (including sentinel lymph nodes). Besides practical aspects, the guidelines consider the needs of the clinicians for appropriate surgical and radiotherapeutic treatment of the patients. Carcinosarcomas are assigned to the endometrial carcinoma as a special variant. For the first time, an algorithmic approach for evaluation of the tumour tissue for Lynch syndrome is given. Prognostic factors based on morphologic findings are summarised.

How to Handle Lymphadenectomy Specimens to Identify Metastasis More Accurately in Gynecologic Pathology

AIM

To identify the value of processing multiple sections to detect metastasis in lymph nodes (LNs) dissected during gynecologic cancer surgery, and to evaluate the sizes of metastatic LNs in each region to compare with the largest one.

MATERIALS AND METHODS

This retrospective study included 362 patients who had gynecologic cancer with at least one metastatic LN. Slides of 627 metastatic LN specimens were categorized according to the processing technique into single and more than one section (MOS) groups. In the MOS group, the LNs were cut into 2 or 3 parallel slices because their greatest dimensions exceeded 0.5 cm. Sizes of LN metastatic foci (MF) were measured and defined as follows: MF ⩽2 mm as micrometastasis and MF >2 mm as macrometastasis. The largest LN diameters among the metastatic LNs and the largest LNs in those regions were measured. Groups were compared using the Kruskal-Wallis test.

RESULTS

Sixty-five (10.3%) of the metastatic LNs included in this study had micrometastases and 40 (6.3%) of them had MF ⩽1 mm. The rate of micrometastasis was higher in the MOS group than in the single-section group (11.8% vs 8.5%, respectively). Twenty-eight percent (n = 175) of metastatic LNs were not the largest, and 55.5% of those were less than 1 cm in diameter.

CONCLUSION

Methods of LN processing and macroscopic evaluation are not standardized, and processing single sections from LNs may overlook micrometastases. The detection rate of micrometastases can be improved by processing multiple sections from LNs.

The role of pathology in the management of patients with endometrial carcinoma

Pathology plays a critical role in every step in the management of endometrial carcinoma patients. In this review, we describe the state of the art of pathological examination, including examination of endometrium biopsy; intra-operative evaluation with gross examination and frozen section; and grossing of hysterectomy specimen and its histological and immunohistochemistry study. The main pathologic findings in each step are described, as well as limitations and difficulties that may ensue. We highlight the important pathologic parameters that determine treatment options and prognosis of endometrial cancer patients.

Sentinel lymph node assessment in endometrial cancer: a systematic review and meta-analysis

BACKGROUND

In the staging of endometrial cancer, controversy remains regarding the role of sentinel lymph node mapping compared with other nodal assessment strategies.

OBJECTIVE

We conducted a systematic review to evaluate the diagnostic accuracy and clinical impact of sentinel lymph node mapping in the management of endometrial cancer.

DATA SOURCES

We searched Medline, Embase, and the Cochrane Central Registry of Controlled trials for studies published in English before March 25, 2016 (PROSPERO CRD42016036503).

STUDY ELIGIBILITY CRITERIA

Studies were included if they contained 10 or more women with endometrial cancer and reported on the detection rate, sensitivity, and/or impact on treatment or survival of sentinel lymph node mapping.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two authors independently reviewed abstracts and full-text articles for inclusion and assessed study quality. The detection rate, sensitivity, and factors associated with successful mapping (study size, body mass index, tumor histology and grade, injection site, dye type) were synthesized through random-effects meta-analyses and meta-regression.

RESULTS

We identified 55 eligible studies, which included 4915 women. The overall detection rate of sentinel lymph node mapping was 81% (95% confidence interval, 77-84) with a 50% (95% confidence interval, 44-56) bilateral pelvic node detection rate and 17% (95% confidence interval, 11-23) paraaortic detection rate. There was no difference in detection rates by patient body mass index or tumor histology and grade. Use of indocyanine green increased the bilateral detection rate compared with blue dye. Additionally, cervical injection increased the bilateral sentinel lymph node detection rate but decreased the paraaortic detection rate compared with alternative injection techniques. Intraoperative sentinel lymph node frozen section increased the overall and bilateral detection rates. The sensitivity of sentinel node mapping to detect metastases was 96% (95% confidence interval, 91-98); ultrastaging did not improve sensitivity. Compared with women staged with complete lymphadenectomy, women staged with sentinel lymph node mapping were more likely to receive adjuvant treatment.

CONCLUSION

Sentinel lymph node mapping is feasible and accurately predicts nodal status in women with endometrial cancer. The current data favors the use of cervical injection techniques with indocyanine green. Sentinel lymph mapping may be considered an alternative standard of care in the staging of women with endometrial cancer.

The Microcystic, Elongated, and Fragmented (MELF) Pattern of Invasion: A Single Institution Report of 464 Consecutive FIGO Grade 1 Endometrial Endometrioid Adenocarcinomas

MELF invasion has been associated with nonvaginal recurrences and lymph node (LN) metastases in multi-institutional case control studies but has not been well examined in large single-institution cohorts. Hysterectomy specimens with FIGO 1 endometrioid endometrial carcinoma and lymphadenectomies from 2007 to 2012 were identified. Electronic medical records and histologic slides were reviewed. Of 464 identified cases, 163 (35.1%) were noninvasive, 60 (12.9%) had MELF, 222 (47.8%) had a component of the infiltrative invasion pattern without MELF, 13 (2.8%) had pure pushing borders of invasion, 5 (1.1%) had pure adenomyosis-like invasion, and 1 (0.2%) had pure adenoma malignum-like invasion. Sixteen cases had LN metastases. Significantly more MELF cases had positive LNs than non-MELF cases overall (18.3% vs. 1.2%, P<0.001). The results were almost identical when invasive infiltrative cases with and without MELF were compared (18.3% vs. 1.8%, P<0.001). The maximum number of MELF glands per slide did not differ between cases with and without LN metastases, P=0.137. A majority of positive LNs, even in MELF cases, demonstrated nonhistiocyte-like metastases. Only 5 cases (all with MELF invasion) demonstrated micrometastatic lesions or isolated tumor cells only. MELF cases demonstrated a nonsignificant decrease in time to extravaginal recurrence (P=0.082, log-rank test), for which analysis was limited by low recurrence rates. In summary, MELF is associated with LN metastases, even when compared with other infiltrative cases and shows multiple patterns of growth in positive LNs. MELF cases additionally trended toward decreased time to extravaginal recurrence.

Sentinel-node mapping in endometrial cancer patients: comparing SPECT/CT, gamma-probe and dye

OBJECTIVE

The aim of this study was to compare preoperative SPECT/CT with gamma-probe and methylene blue-dye (MBD) in the identification of sentinel lymph node (SLN) in early stage endometrial cancer.

METHODS

40 stage-I EC patients (66.7 ± 9.7 years) underwent preoperative lymphoscintigraphy. After about 3 h from Tc-99m-albumin nanocolloid cervical injection, all patients underwent SPECT/CT study. MBD was injected into the cervix just before surgery under general anesthesia. All patients underwent SLN biopsy, hysterectomy, bilateral salpingo-oophorectomy, and radical regional lymphadenectomy. SPECT/CT findings were compared to those of gamma-probe and MBD techniques.

RESULTS

In 2 patients no nodal migration was observed, neither with MBD nor radiotracer. Detection rate of at least one SLN was 90% (36/40 patients) with SPECT/CT, 88% (35/40) intra-operatively with gamma-probe and 80% (32/40) with MBD. Only in 7/40 patients a bilateral migration was obtained with all considered modalities. In particular, bilateral detection was achieved in 26 patients with SPECT/CT, in 24 with gamma-probe and in 10 patients with MBD. The concordance site between SPECT/CT and intraoperative gamma-probe was 73% (29/40 patients: 2 without migration, 21 bilateral and 6 monolateral SLNs); while concordance site with MBD was found in 40% (16/40: 8 bilateral, 6 monolateral SLNs, 2 without SLNs). Overall, 628 LNs were dissected (mean 18 LNs per patient). The median number of SLNs removed was 2 (mean 2.5 per patient). Out of 91 SLNs: 43 were "hot and blue (HB)", 10 were blue only and 38 were hot only. LN metastases rate was 16%: 9/90 SLNs (7 HB, 2 hot only) were positive for metastases in 6 patients. Four non-SLNs were found positive in 3 patients, and all presented concomitant positive SLNs. False negative rate was 0%.

CONCLUSIONS

SPECT/CT had the highest detection rate and achieved the highest rate of bilateral mapping, compared to gamma-probe and MDB. SPECT/CT had moderate concordance with gamma-probe, and it can help the intraoperative detection of SLNs providing important information about their anatomic location.

[Early-stage endometrial cancer: Sentinel node or lymphadenectomy?]

The endometrial cancers are mainly discovered at an early stage justifying a less aggressive treatment. The therapeutic choices are today based on preoperative classifications themselves based on histo-prognostic factors of the tumor and its extension measured in MRI: consequently, lymph node dissection in case of low and intermediate risk cancer is not systematically achieved. But a number of patients have lymph node involvement finally, probably justifying an adapted surgical and adjuvant treatment. The technique of sentinel node would compensate the weaknesses of preoperative prognostic evaluation. This new operative technique needs to be precised and evaluated: the topics subject to discussion are the technical implementation, the definition of its quality standards and the management of its histological results especially in cases of low volume lymph node metastasis.