A prospective assessment of the reliability of frozen section to direct intraoperative decision making in endometrial cancer

Can mismatch repair status be added to sentinel lymph node mapping algorithm in endometrioid endometrial cancer?

OBJECTIVE

To evaluate the relation between mismatch repair (MMR) status and the risk of lymph node metastasis in endometrial cancer, and whether this additional data can be incorporated to current SLN (sentinel lymph node) algorithm.

METHODS

We included a series of 332 women that underwent SLN mapping ± systematic lymphadenectomy from January 2013 to December 2021. Protein expressions of MLH1, MSH2, MSH6, PMS2 were examined by immuno-histochemistry and considered MMRd (deficient) when at least one protein was not expressed.

RESULTS

MMRd was noted in 20.8% of cases and correlated to grade 3 (p = 0.018) and presence of lymphovascular space invasion (p = 0.032). Moreover, MMRd was an independent risk factor for lymph node metastasis (OR 2.76, 95% CI 1.36-5.62). Notably, 21.7% (15/69) cases with MMRd had lymph node metastasis compared to 9.5% (25/263) of cases with MMRp (proficient) (p = 0.005). The overall and bilateral SLN detection rates were 91.9% and 75.9%, respectively. Of the 80 (24%) cases of non-bilateral SLN detection, 66.2% had low-grade tumors (G1/G2) and myometrial invasion <50%. Considering MMR status an independent prognostic factor for lymph node metastasis, a systematic lymphadenectomy (side specific or bilateral) would forgo in 53.7% (43/80) of cases with non-bilateral detection, representing 13% (43/332) of all endometroid tumors.

CONCLUSION

MMR status was independently related to lymph node metastasis in endometrioid EC. Moreover, MMR status may help to select patients that can forgo systematic lymphadenectomy in case of undetected SLN.

Endometrial stripe thickness: a preoperative marker to identify patients with endometrial intraepithelial neoplasia who may benefit from sentinel lymph node mapping and biopsy

OBJECTIVES

The goal of our study was to identify preoperative factors in patients with endometrial intraepithelial neoplasia that are associated with concurrent endometrial cancer to select patients who may benefit from sentinel lymph node (SLN) assessment at the time of hysterectomy.

METHODS

Retrospective single institution cohort study of patients with a preoperative diagnosis of endometrial intraepithelial neoplasia who underwent hysterectomy with or without staging from January 2010 to July 2020. Modified Poisson regression was used to calculate risk ratios (RR) and 95% confidence intervals (CI).

RESULTS

Of 378 patients with a preoperative diagnosis of endometrial intraepithelial neoplasia, 275 (73%) had endometrial intraepithelial neoplasia and 103 (27%) had invasive cancer on final pathology. Age (p=0.003), race (p=0.02), and hypertension (p=0.02) were significantly associated with concurrent endometrial cancer. The median preoperative endometrial stripe was significantly greater in the endometrial cancer group (14 mm (range 10-19)) than in the endometrial intraepithelial neoplasia group (11 mm (range 8-16); p=0.002). A preoperative endometrial stripe ≥20 mm was associated with double the risk of endometrial cancer on final pathology (crude RR 2.0, 95% CI 1.3 to 2.9) and preoperative endometrial stripe ≥15 mm was 2.5 times more likely to be associated with high risk Mayo criteria on final pathology (crude RR 2.5, 95% CI 1.2 to 5.2). Of those with concurrent endometrial cancer, 5% were stage IB, 29% had tumors >2 cm, and 1% had grade 3 histology. Only 3% of all patients underwent lymph node evaluation.

CONCLUSIONS

In a large cohort of patients with a preoperative diagnosis of endometrial intraepithelial neoplasia, less than a third had invasive cancer and even fewer had pathologic features considered high risk for nodal metastasis, arguing against the use of routine SLN dissection in these patients. Endometrial stripe ≥15 mm may be a useful preoperative marker to identify patients at higher risk for concurrent endometrial cancer and may be an important criterion for use of selective SLN dissection in carefully selected patients with endometrial intraepithelial neoplasia.

Role of sentinel lymph node biopsy for gynecologic cancers

PURPOSE OF REVIEW

To provide an overview of the current knowledge and recent advances of sentinel lymph node (SLN) assessment in uterine, cervical, vulvar, and ovarian cancers.

RECENT FINDINGS

In endometrial cancer, SLN evaluation has become increasingly utilized as part of the treatment of early-stage disease, with data showing improved detection of pelvic lymph node metastasis. In cervical cancer, SLN biopsy has also gained increasing traction with studies demonstrating the feasibility and accuracy of SLN detection. Evaluation with frozen section, however, remains limited in the detection of metastases. The prognostic significance of positive SLN in vulvar cancer is currently being investigated, with preliminary data showing lower recurrence rates in patients receiving adjuvant radiation.

SUMMARY

SLN evaluation remains standard of care to detect lymph node metastasis in early-staged endometrial cancer. In cervical cancer, SLN biopsy has been shown to be reliable, while decreasing morbidity without impacting disease-free survival in select patients. The technique and high sensitivity of SLN biopsy in vulvar cancer has been demonstrated in large prospective trials. There are no randomized controlled trials in ovarian cancer that evaluate the role of SLN biopsy on treatment and outcome; current SLN evaluation remains investigational.

The accuracy and clinical impact of intraoperative frozen section in determining the extent of surgical intervention in patients with early stage endometrial cancer

The aim of this study was to compare intraoperative frozen section (FS) with the final pathology (FP), and determine its clinical impact in clinically apparent early stage endometrial cancer (EC) at the American University of Beirut Medical Center (AUBMC). Data for patients 18 years or older, with clinically apparent early stage, grade 1 or 2, endometrioid EC, who underwent hysterectomy ± lymph node dissection (LND) at AUBMC between January 1^st 1996 and June 30^th 2016 were retrospectively reviewed. 70 patients were included. The overall concordance between FS and FP was 92.3% for histological subtype, 77% for tumour grade, 82% for Myometrial invasion (MI) and 100% for tumour size. At a median follow up of 30 months, 8 recurrences (11.4%) were noted, with a 5-year PFS and OS of 76 and 84% respectively, with a trend towards lower recurrence and improved survival in patients who underwent FS or LND.Impact statementWhat is already known on this subject? Hysterectomy and bilateral salpingo-oophorectomy is the standard surgery for stage I endometrial cancer (EC). Intraoperative frozen section (FS) facilitates the decision on performing lymph node dissection (LND). However, its accuracy and clinical impact have been questioned.What do the results of this study add? Our objective is to compare FS with the final pathology (FP), and determine its clinical impact in clinically apparent early stage EC at the American University of Beirut Medical Center (AUBMC). There is a lack of standardisation regarding FS use and reporting at AUBMC.What are the implications of these findings for clinical practice and/or further research? The strong correlation between FS and FP can serve as a tool to guide decision to perform LND in patients with apparent early stage disease, where use of sentinel LN biopsy technique is not available.

Evaluation of frozen section biopsy for fast track diagnosis of endometrial pathology in high-risk women with abnormal uterine bleeding

OBJECTIVE

To study the accuracy of frozen section biopsy for endometrial pathology in high-risk women with abnormal uterine bleeding (AUB).

STUDY DESIGN

A case-control study was conducted between November 2017 to April 2019, a total of 150 women with postmenopausal bleeding, perimenopausal AUB, and high-risk women of age < 40 years with AUB were recruited. All women underwent transvaginal sonography and Doppler, based on age-appropriate endometrial thickness cut-offs 80 women then underwent hysteroscopy. Based on hysteroscopy, women suspicious of malignancy were taken as cases (n = 40) and those with benign findings as controls (n = 40). All cases and controls underwent dilatation and curettage (D & C) with frozen section (FS) and routine histopathology.

RESULTS

The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR), negative LR, and overall test accuracy of FS were 90.9%, 93.19%, 83.33%, 96.19%, 13.8, 0.1 and 86.25% respectively for diagnosing endometrial hyperplasia and cancer taking histopathology as the gold standard. Correlation between frozen section biopsy and histopathology was highly significant (p < 0.001) on D & C specimens and the level of agreement was good (K = 0.778).

CONCLUSION

In women suspicious of malignancy on hysteroscopy, frozen section has high accuracy on D&C specimen and can be used to diagnose endometrial hyperplasia and cancer in an effort to fast-track investigations and work-up for definitive treatment while awaiting final histopathology.

Preoperative and intraoperative assessment of myometrial invasion in endometrial cancer-A Swedish Gynecologic Cancer Group (SweGCG) study

INTRODUCTION

Deep myometrial invasion (≥50%) is a prognostic factor for lymph node metastases and decreased survival in endometrial cancer. There is no consensus regarding which pre/intraoperative diagnostic method should be preferred. Our aim was to explore the pattern of diagnostic methods for myometrial invasion assessment in Sweden and to evaluate differences among magnetic resonance imaging (MRI), transvaginal sonography, frozen section, and gross examination in clinical practice.

MATERIAL AND METHODS

This is a nationwide historical cohort study; women with endometrial cancer with data on assessment of myometrial invasion and FIGO stage I-III registered in the Swedish Quality Registry for Gynecologic Cancer (SQRGC) between 2017 and 2019 were eligible. Data on age, histology, FIGO stage, method, and results of myometrial invasion assessment, pathology results, and hospital level were collected from the SQRGC. The final assessment by the pathologist was considered the reference standard.

RESULTS

In the study population of 1401 women, 32% (n = 448) had myometrial invasion of 50% of more. The methods reported for myometrial invasion assessment were transvaginal sonography in 59%, MRI in 28%, gross examination in 8% and frozen section in 5% of cases. Only minor differences were found for age and FIGO stage when comparing methods applied for myometrial invasion assessment. The sensitivity, specificity, and accuracy to find myometrial invasion of 50% or more with transvaginal sonography were 65.6%, 80.3%, and 75.8%, for MRI they were 76.9%, 71.9%, and 73.8%, for gross examination they were 71.9%, 93.6%, and 87.3%, and for frozen section they were 90.0%, 92.7%, and 92.0%, respectively.

CONCLUSIONS

In Sweden, the assessment of deep myometrial invasion is most often performed with transvaginal sonography, but the sensitivity is lower than for the other diagnostic methods. In clinical practice, the accuracy is moderate for transvaginal sonography and MRI.

Accuracy of intra-operative frozen section in guiding surgical staging of endometrial cancer

PURPOSE

Surgery consists the main treatment of endometrial cancer; however, decision of lypmhadenectomy is controversial. Intra-operative frozen section (FS) is commonly used in guiding surgical staging; nevertheless, there are different reports regarding its adequacy and reliability. Aim of this study is to assess accuracy of FS in predicting paraffin section (PS) results in patients with endometrium cancer.

METHODS

Data of 223 cases, who were operated for endometrial cancer at a tertiary hospital in 2012-2019, were analyzed retrospectively. Histological type, grade, tumor diameter, depth of myometrial invasion, and cervical and adnexal involvement in frozen and paraffin section were evaluated. Positive and negative predictive values and accuracy of frozen results in predicting paraffin results for each parameter was assessed. Statistical significance was taken as 0.05 in all tests.

RESULTS

Accuracy of FS in predicting PS results were 76.23% for histology, 75.45% for grade, 85.31% for depth of myometrial invasion, and 95.45% for tumor diameter. Surgery, based on FS results, caused undertreatment in 4 patients, while metastatic lymph node ratios were found in only 35.3-50.0% of cases who had high risk parameters at FS.

CONCLUSION

Our FS results have reasonable accuracy rates in predicting PS results, in comparison with the previous literature. However, even if the high risk parameters detected in FS predict PS accurately, absence of lymph node involvement in all cases with high risk parameters indicates that FS-based triage cannot prevent unnecessary lymphadenectomies.

Lymph node evaluation in endometrial cancer: how did it change over the last two decades?

Endometrial cancer (EC) is the most common gynecological malignancy in developed countries, and surgery represents the pivotal part of treatment. Hysterectomy and salpingo-oophorectomy allow removing the primary tumor and defining patients at higher risk, who might benefit from adjuvant therapies. Minimally invasive surgery is associated with superior postoperative outcomes and represents a safe and effective approach for surgical staging of EC. The lymph node status evaluation in EC is still a matter of debate. Over the last twenty years much has changed, moving from a full systematic pelvic and paraaortic lymphadenectomy for staging purpose to the removal of the pelvic (with or without paraaortic) lymph nodes only in selected EC classes of risk. Two randomized trials failed to demonstrate survival benefits of lymphadenectomy in case of apparent early stage EC; however, its prognostic role has never been questioned. At present, with the aim of reducing the surgical-related morbidity, sentinel node mapping is emerging as a safe and valid alternative to lymphadenectomy for EC staging, demonstrating high accuracy and an increased detection of lymph nodes metastasis. Here, we performed a review of the most significant studies, which supported the changes in the lymph node status evaluation for EC over the last two decades.

Effect of Pelvic Lymphadenectomy on Survival in Patients with Low-Risk Early-Stage Endometrial Cancer Diagnosed Intraoperatively Using Frozen Tissue Sections: A Retrospective Analysis

Purpose

To determine whether pelvic lymphadenectomy improved survival in patients diagnosed with low-risk early-stage endometrial cancer by intraoperative pathology.

Methods

This retrospective analysis included 238 patients at our hospital.

Results

The lymphadenectomy and non-lymphadenectomy groups contained 121 and 117 patients, respectively. In both groups, more than half the patients had tumor size ≥2 cm, and most had myometrial invasion <50%, stage Ia disease and no lymphovascular space invasion. Age, tumor size, myometrial invasion, surgical-pathologic stage and postoperative adjuvant therapy use were comparable between groups. The non-lymphadenectomy group had more patients treated laparoscopically (36.8% vs 10.7%; P<0.001) and fewer patients with histologic grade 2 disease (35.9% vs 62.8%; P<0.001) than the lymphadenectomy group. In the non-lymphadenectomy group, intraoperative frozen section pathology disagreed with postoperative pathology in only 31/117 cases for histologic grade (none upgraded to grade 3), 1/117 cases for myometrial invasion (one case revised from <50% to ≥50%) and 3/117 cases for surgical-pathologic stage (upgraded from Ia to Ib or II). Disease recurrence rate and overall survival did not differ significantly between the lymphadenectomy and non-lymphadenectomy groups. In multivariate Cox regression analysis, only surgical-pathologic stage >Ia (odds ratio, 47.7; 95% confidence interval, 6.7–340.8; P=0.031) was associated with increased odds of disease recurrence.

Conclusion

Pelvic lymphadenectomy may not be necessary in patients with an intraoperative diagnosis of low-risk endometrial cancer.

Molecular characterization in the prediction of disease extent in endometrial carcinoma

OBJECTIVE

Patients with endometrial carcinoma are usually triaged to staging lymphadenectomy selectively based on estimated risk of lymphatic spread. The risk is generally assessed by the presence of uterine risk factors, but their preoperative and intraoperative identification remain a challenge. The objective of this study was to assess the capability of molecular classification, described by The Cancer Genome Atlas (TCGA), to predict the stage of endometrial carcinoma.

STUDY DESIGN

Sequencing of polymerase-ε (POLE) and immunohistochemistry of mismatch repair (MMR) proteins and p53 were performed to stratify endometrial carcinomas into subgroups of POLE exonuclease domain mutation (EDM), MMR deficiency, abnormal p53 (p53 abn) and 'no specific molecular profile' (NSMP). NSMP was the reference subgroup for comparisons. Associations of molecular subgroups and uterine risk factors with stage were examined in univariable and multivariable analyses.

RESULTS

Six hundred and four patients were included in the study. None of the POLE EDM tumours extended beyond the uterine cervix. In an unadjusted analysis, p53 abn was associated with increased risk for stage IIIC-IV disease [odds ratio (OR) 4.6, 95% confidence interval (CI) 2.3-9.2; p < 0.0005]. When controlling for uterine risk factors (histotype and grade, depth of myometrial invasion, tumour size, lymphovascular space invasion), p53 was not an independent predictor of advanced disease. In contrast, POLE EDM independently predicted local disease (OR 0.12, 95% CI 0.015-0.99; p = 0.049 for stage II-IV cancer). Of the molecular subgroups, p53 abn was most strongly associated with the presence of high-risk uterine factors (ORs between 2.2 and 19; p ≤ 0.010).

CONCLUSION

Of the TCGA-based molecular subgroups, POLE EDM independently predicted early-stage endometrial carcinoma. Although p53 abn was not an independent predictor of advanced disease, its association with uterine risk factors could allow utilization of molecular data in deciding the type of staging surgery if knowledge of uterine factors is deficient.

A Modern Approach to Endometrial Carcinoma: Will Molecular Classification Improve Precision Medicine in the Future?

Endometrial cancer has been histologically classified as either an estrogen-dependent cancer with a favorable outcome or an estrogen-independent cancer with a worse prognosis. These parameters, along with the clinical attributions, have been the basis for risk stratification. Recent molecular and histopathological findings have suggested a more complex approach to risk stratification. Findings from the Cancer Genome Atlas Research Network established four distinctive genomic groups: ultramutated, hypermutated, copy-number low and copy-number high prognostic subtypes. Subsequently, more molecular and histopathologic classifiers were evaluated for their prognostic and predictive value. The impact of molecular classification is evident and will be recognized by the upcoming WHO classification. Further research is needed to give rise to a new era of molecular-based endometrial carcinoma patient care.

Combination of sentinel lymph node mapping and uterine frozen section examination to reduce side-specific lymphadenectomy rate in endometrial cancer: a Turkish Gynecologic Oncology Group study (TRSGO-SLN-002)

OBJECTIVE

This study aimed to find out whether side-specific pelvic lymphadenectomy can be omitted without compromising diagnostic efficacy according to "reflex frozen section" analysis of the uterus in case of sentinel lymph node (SLN) mapping failure.

METHODS

Patients who underwent surgery for endometrial cancer with an SLN algorithm were stratified as low-risk or high-risk according to the uterine features on the final pathology reports. Two models for low-risk patients were defined to omit side-specific pelvic lymphadenectomy: strategy A included patients with endometrioid histology, grade 1-2, and <50% myometrial invasion irrespective of the tumor diameter; strategy B included all factors of strategy A with the addition of tumor diameter ≤2 cm. Theoretical side-specific pelvic lymphadenectomy rates were calculated for the two strategies, assuming side-specific pelvic lymphadenectomy was omitted if low-risk features were present on reflex uterine frozen examination, and compared with the standard National Comprehensive Cancer Network (NCCN) SLN algorithm.

RESULTS

372 endometrial cancer patients were analyzed. 230 patients (61.8%) had endometrioid grade 1 or 2 tumors with <50% myometrial invasion (strategy A), and in 123 (53.4%) of these patients the tumor diameter was ≤2 cm (strategy B); 8 (3.5%) of the 230 cases had lymphatic metastasis. None of them were detected by side-specific pelvic lymphadenectomy and metastases were limited to SLNs in 7 patients. At least one pelvic side was not mapped in 107 (28.8%) cases in the entire cohort, and all of these cases would require a side-specific pelvic lymphadenectomy based on the NCCN SLN algorithm. This rate could have been significantly decreased to 11.8% and 19.4% by applying reflex frozen section examination of the uterus using strategy A and strategy B, respectively.

CONCLUSION

Reflex frozen section examination of the uterus can be a feasible option to decide whether side-specific pelvic lymphadenectomy is necessary for all the patients who failed to map with an SLN algorithm. If low-risk factors are found on frozen section examination, side-specific pelvic lymphadenectomy can be omitted without compromising diagnostic efficacy for lymphatic spread.

Challenges to Intraoperative Evaluation of Endometrial Cancer

BACKGROUND AND OBJECTIVES

Intraoperative evaluation of the uterus has been reported to predict risk of lymph node spread in endometrial cancer. Four criteria have been prospectively validated by the Mayo Clinic; histopathology, grade, tumor size, and depth of myometrial invasion. The objective of this study is to assess the accuracy of intraoperative evaluation in a university-affiliated teaching setting.

METHODS

This study was a retrospective chart review of 105 cases of endometrial cancer who underwent robotic-assisted staging from January 2016 through December 2017.

RESULTS

Seventy-five cases were included. The mean age was 65 y and mean body mass index was 33 kg/m2. Fifty-eight patients (80.6%) had no change between intraoperative and postoperative grade. This yielded a 19.4% discordance rate with a significant disagreement (P = .003, Cohen's κ = 0.705). Fifty-eight patients (82.9%) had no change in depth of invasion. This yielded a 17.1% discordance rate with a significant disagreement (P = .0498, Cohen's kappa of 0.69 [95% confidence interval, 0.53-0.85]). Average tumor diameter was 3.4 cm. Seven patients (11.7%) were upsized from the low-risk (≤2 cm) to the high-risk category (>2 cm). This led to an 11.7% discordance rate, with a significant disagreement (P = .008, Cohen's kappa of 0.69 [95% confidence interval, 0.48-0.89]). In 15 of 75 cases (20%), intraoperative evaluation of the size of the tumor was not possible and deferred to the final pathology report.

CONCLUSION

We conclude the Mayo Clinic Criteria cannot be universally adopted until all four criteria can be validated through a prospective study that includes institutions that have variable resources.

Implementation of a sentinel lymph node mapping algorithm for endometrial cancer: surgical outcomes and hospital charges

INTRODUCTION

The purpose of this study was to compare operative times, surgical outcomes, resource utilization, and hospital charges before and after the implementation of a sentinel lymph node (SLN) mapping algorithm in endometrial cancer.

METHODS

All patients with clinical stage I endometrial cancer were identified pre- (2012) and post- (2017) implementation of the SLN algorithm. Clinical data were summarized and compared between groups. Total hospital charges incurred on the day of surgery were extracted from the hospital financial system for each patient and all charges were adjusted to 2017 US dollars.

RESULTS

A total of 203 patients were included: 71 patients in 2012 and 130 patients in 2017. There was no difference in median age, body mass index, or stage. In 2012, 35/71 patients (49.3%) underwent a lymphadenectomy. In 2017, SLN mapping was attempted in 120/130 patients (92.3%) and at least one SLN was identified in 110/120 (91.7%). Median estimated blood loss was similar between groups (100 mL vs 75 mL, p=0.081). There was a significant decrease in both median operative time (210 vs 171 min, p=0.007) and utilization of intraoperative frozen section (63.4% vs 14.6%, p<0.0001). No significant differences were noted in intraoperative (p=1.00) or 30 day postoperative complication rates (p=0.30). The median total hospital charges decreased by 2.73% in 2017 as compared with 2012 (p=0.96).

DISCUSSION

Implementation of an SLN mapping algorithm for high- and low-risk endometrial cancer resulted in a decrease in both operative time and intraoperative frozen section utilization with no change in surgical morbidity. While hospital charges did not significantly change, further studies are warranted to assess the true cost of SLN mapping.

Sentinel lymph node mapping in endometrial and cervical cancer: a survey of practices and attitudes in gynecologic oncologists

Objective

To determine patterns among gynecologic oncologists in sentinel lymph node mapping (SLNM) for endometrial cancer (EC) and cervical cancer (CC).

Methods

A online survey assessing the practice of SLNM, including incidence, patterns of usage, and reasons for non-use was distributed to Society of Gynecologic Oncology candidate and full members in August 2017. Descriptive statistics and univariate analysis was performed.

Results

The 1,117 members were surveyed and 198 responses (17.7%) were received. Of the 70% (n=139) performing SLNM, the majority reported use for both CC and EC (64.0%) or EC alone (33.1%). In those using SLNM in EC, the majority (86.6%) performed SLNM in >50% of cases for all patients (56.3%), International Federation of Gynecology and Obstetrics grade 1 (43.0%) and 2 (42.2%). Reported benefits of SLNM in EC were reduced surgical morbidity (89.6%), lymphedema (85.2%), and operative time (63.7%). Among those using SLNM for CC, the majority (73.1%) did so in >50% of cases. In EC, 77.2% and 21.3% reported that micro-metastatic disease (0.2–2.0 cm) and isolated tumor cells (ITCs) should be treated as node positive, respectively. In those not using SLNM for EC (n=64) and CC (n=105), concerns were regarding efficacy of SLNM and lack of training. When queried regarding training, 73.7% felt that SLNM would impact skill in full lymphadenectomy (LND).

Conclusion

The SLNM is utilized frequently among gynecologic oncologists for EC and CC staging. Common reasons for non-uptake include uncertainty of current data, lack of training and technology. Concerns exist regarding impact of SLNM in fellowship training of LND.

Sentinel lymph node biopsy in early stage endometrial cancer: a Turkish gynecologic oncology group study (TRSGO-SLN-001)

OBJECTIVE

The aim of this multicenter study was to evaluate the feasibility of sentinel lymph node (SLN) mapping in clinically uterine confined endometrial cancer.

METHODS

Patients who underwent primary surgery for endometrial cancer with an SLN algorithm were reviewed. Indocyanine green or blue dye was used as a tracer. SLNs and/or suspicious lymph nodes were resected. Side specific lymphadenectomy was performed when mapping was unsuccessful. SLNs were ultrastaged on final pathology.

RESULTS

357 eligible patients were analyzed. Median age was 59 years. Median number of resected SLNs was 2 (range 1-12) per patient. Minimal invasive and open surgeries were performed in 264 (73.9%) and 93 (26.1%) patients, respectively. Indocyanine green was used in 231 (64.7%) and blue dye in 126 (35.3%) patients. The dyes were injected into the cervix in 355 (99.4%) patients. The overall and bilateral SLN detection rates were 91.9% and 71.4%, respectively. The mapping rates using indocyanine green or blue dye were comparable (P=0.526). There were 43 (12%) patients with lymphatic metastasis. The SLN algorithm was not able to detect 3 of 43 patients who had isolated paraaortic metastasis. After SLN biopsy, complete pelvic lymphadenectomy was performed in 286 (80.1%) patients. Sensitivity and negative predictive value were both 100% for the detection of pelvic lymph node metastases. In addition, 117 (32.8%) patients underwent completion paraaortic lymphadenectomy after SLN biopsy. In these patients, sensitivity for detecting metastases to pelvic and/or paraaortic lymph nodes was 90.3% with a negative predictive value of 96.6%. The risk of non-SLN involvement in patients with macrometastatic SLNs, micrometastatic SLNs, and isolated tumor cells in SLNs were 61.2%, 14.3% and 0%, respectively.

CONCLUSIONS

SLN biopsy had good accuracy in detecting lymphatic metastasis. However, one-third of cases with metastatic SLNs also had non-SLN involvement and this risk increased to two-thirds of cases with macrometastatic SLNs. The effect of leaving these nodes in situ on survival should be evaluated in further studies.

Application of transvaginal three-dimensional power Doppler ultrasound in benign and malignant endometrial diseases

To investigate the value of transvaginal three-dimensional (3D) power Doppler ultrasound in the diagnosis of benign and malignant endometrial diseases.A total of 144 patients with endometrial thickness ≥4 mm were enrolled. Endometrial thickness was measured by transvaginal 3D B-mode ultrasound, while blood signals were detected by 3D power Doppler ultrasound. Endometrial volume (EV), vascularization index (VI), blood flow index (FI), and vascularization flow index (VFI) were calculated. All histopathological diagnoses of endometrium were obtained.There were 86 benign and 58 malignant cases. There were statistically significant differences between two groups in endometrial thickness [1.50 (1.30, 1.80) vs 2.30 (1.80, 3.20), P < .001], EV [10.62 (7.14, 17.36) vs 28.94 (9.59, 67.96), P < .001], VI [6.07 (3.61, 10.33) vs 12.01 (7.50, 19.87), P = .001], FI [27.42 (24.45, 31.33) vs 32.98 (30.22, 35.40), P < .001], and VFI [1.58 (0.92, 3.32) vs 4.28 (2.24, 6.41), P < 0.001]. Sensitivity and specificity of endometrial thickness were relatively high [endometrial thickness (86.2%, 76.1%), EV (48.3%, 97.7%), VI (72.4%, 69.8%), FI (72.4%, 74.4%), and VFI (72.4%, 74.4%)]. There was no significant difference in any parameters of the endometrium between different stages (Ia, Ib, II, and above) or phases (G1, G2, and G3) of Ia phase of endometrial cancer (all P > .05).Transvaginal 3D power Doppler ultrasound is valuable in the differentiating benign and malignant endometrial lesions.

Sentinel Lymph Node Ultra-staging as a Supplement for Endometrial Cancer Intraoperative Frozen Section Deficiencies

For endometrial cancer (EC), most surgeons rely on intraoperative frozen section (IFS) to determine the risk of nodal metastasis and necessity of lymphadenectomy. IFS remains a weak link in this practice due to its susceptibility to diagnostic errors. As a less invasive alternative, sentinel lymph node (SLN) mapping and ultra-staging have gradually gained acceptance for EC. We aimed to establish the SLN success rate, negative predictive value, and whether SLNs provide useful information for cases misdiagnosed on IFS. From 2013 to 2017, 100 patients (63 low-risk and 37 high-risk EC) underwent hysterectomy, bilateral salpingo-oophorectomy, and SLN. Among them, 56 had additional pelvic lymphadenectomy. A total of 337 SLNs were obtained in 86 cases: 55 bilaterally and 31 unilaterally. The remaining 14 cases failed because of patient obesity or leiomyoma. Pathology ultra-staging detected 2 positive SLNs from 2 patients (1 with isolated tumor cells, 1 with micrometastases). One of 773 nonsentinel pelvic nodes was positive on the contralateral hemi-pelvis in a patient who was mapped unilaterally, resulting in negative predictive value of 100%. During IFS, tumor grade and/or depth of myometrial invasion was misdiagnosed in 22 cases (22%). These errors would have resulted in under-staging in 10 high-risk patients or over-staging in 4 low-risk patients. SLNs were mapped in these misestimated patients, with one revealing metastases. SLN provides invaluable information on nodal status while detecting occult metastases in cases misdiagnosed on IFS. Our findings justify the incorporation of SLN in initial surgery for EC as an offset to IFS diagnostic errors, minimizing their negative impact on patient care.

A novel prediction method for lymph node involvement in endometrial cancer: machine learning

OBJECTIVE

The necessity of lymphadenectomy and the prediction of lymph node involvement (LNI) in endometrial cancer (EC) have been hotly-debated questions in recent years. Machine learning is a broad field that can produce results and estimations. In this study we constructed prediction models for EC patients using the Naïve Bayes machine learning algorithm for LNI prediction.

METHODS

The study assessed 762 patients with EC. Algorithm models were based on the following histopathological factors: V1: final histology; V2: presence of lymphovascular space invasion (LVSI); V3: grade; V4: tumor diameter; V5: depth of myometrial invasion (MI); V6: cervical glandular stromal invasion (CGSI); V7: tubal or ovarian involvement; and V8: pelvic LNI. Logistic regression analysis was also used to evaluate the independent factors affecting LNI.

RESULTS

The mean age of patients was 59.1 years. LNI was detected in 102 (13.4%) patients. Para-aortic LNI (PaLNI) was detected in 54 (7.1%) patients, of which four patients had isolated PaLNI. The accuracy rate of the algorithm models was found to be between 84.2% and 88.9% and 85.0% and 97.6% for LNI and PaLNI, respectively. In multivariate analysis, the histologic type, LVSI, depth of MI, and CGSI were independently and significantly associated with LNI (p<0.001 for all).

CONCLUSIONS

Machine learning may have a place in the decision tree for the management of EC. This is a preliminary report about the use of a new statistical technique. Larger studies with the addition of sentinel lymph node status, laboratory findings, or imaging results with machine learning algorithms may herald a new era in the management of EC.

Surgical staging in endometrial cancer

In several malignancies, it has been demonstrated that the lymph nodal status is the most important pathologic factor affecting prognosis and giving the indication to further adjuvant treatment. The surgical assessment of the lymph nodal status in endometrial cancer is debated since 30 years. Recently, the sentinel lymph node mapping is rapidly gaining clinical acceptance in endometrial cancer. The adoption of Indocyanine Green as a safe and user friendly tracer for sentinel lymph node mapping increased the speed to which this procedure is getting applied in clinical practice. As a consequence of this rapid growth, several fundamental questions have been raised and are still debatable. In this manuscript, we discuss the importance of a known pathological lymph nodal status, the technique of the sentinel lymph node mapping with the reported false negative rates and detection rates according to the different tracers adopted, and the clinical scenarios in which a sentinel lymph node mapping could be employed.

Sentinel node biopsy for treatment of endometrial cancer: current perspectives

The risk of lymph nodal metastases in endometrial cancer varies greatly according to the characteristics of the primary tumor. Surgical staging with a systematic lymphadenectomy in endometrial cancer is debated since three decades. On one hand, it provides important pathological information on the spread of the tumor allowing for an appropriate decision making on adjuvant treatment but on the other side it is characterized by a non-negligible short and long-term morbidity. In the past decade, various efforts have been made in the attempt to apply the concept of the sentinel lymph node mapping in endometrial cancer. The sentinel lymph node mapping has the potential to provide the necessary pathological lymph nodal information at a reasonable cost in terms of morbidity. In this review, the most relevant aspects of the sentinel lymph node mapping in endometrial cancer are summarized. Furthermore, the performance in terms of false negative rates and detection rates, the clinical value of the pathological ultrastaging, its clinical applicability in different scenarios including patients preoperatively considered to be at low or at high risk are discussed. Oncological outcome of the patients who have been submitted to a sentinel lymph node mapping as compared to a full lymhadenectomy are presented as well as technical aspects to improve the performance of the surgical technique.

The diagnostic accuracy of fluorodeoxyglucose-positron emission tomography/computed tomography and sentinel node biopsy in the prediction of pelvic lymph node metastasis in patients with endometrial cancer: A retrospective observational study

According to the sentinel node biopsy (SNB), systematic pelvic lymph node dissection (PLND) may not be needed for patients with early-stage endometrial cancer. On the other hand, imaging technology including fluorodeoxyglucose-positron emission tomography/computed tomography (FDG PET/CT) has been developing worldwide. The aim of this study was to evaluate the combined diagnostic accuracy of FDG PET/CT and SNB in the prediction of pelvic lymph node metastasis in endometrial cancer patients.One hundred twenty-one patients with endometrial cancer underwent FDG PET/CT before hysterectomy and received SNB followed by systematic PLND. Univariate and multivariate analyses were performed to compare the diagnostic accuracy of FDG PET/CT and SNB in the prediction of pelvic node metastasis to the ultimate histologic status.FDG PET/CT had lower sensitivity (36.8% versus 57.9%, P = .1) and a higher specificity (96.4% versus 84.8%, P < .01) than SNB. The kappa statistics of FDG PET/CT and SNB were 0.37 (95% CI, 0.15-0.59) and 0.72 (95% CI, 0.53-0.90), respectively. The sensitivity of SNB was significantly higher than that of FDG PET/CT in all hemi-pelvises (HPs) in which the short axis of the largest metastatic lymph node was <5 mm in diameter (72.7% versus 18.2%, P = .01). In contrast, the sensitivity of FDG PET/CT was higher than that of SNB in all HPs in which the short axis of the largest metastatic lymph node was ≥5 mm in diameter (62.5% versus 37.5%, P = .2); however, the difference was not statistically significant. When the combined diagnosis of FDG PET/CT and SNB was made, the sensitivity and specificity were 84.2% and 82.1%, respectively.SNB was more useful for detecting lymph node metastasis than FDG PET/CT, especially in patients with small metastatic lymph nodes. The combined diagnosis of FDG PET/CT and SNB improves the sensitivity; PET-positive nodes should be dissected regardless of SNB status and HPs in which SNB was not detected should be dissected systematically regardless of FDG PET/CT status.

Retrospective validation of the laparoscopic ICG SLN mapping in patients with grade 3 endometrial cancer

PURPOSE

To evaluate the sensitivity, negative predictive value (NPV) and false-negative (FN) rate of the near infrared (NIR) indocyanine green (ICG) sentinel lymph node (SLN) mapping in patients with poorly differentiated endometrial cancer who have undergone a full pelvic and para-aortic lymphadenectomy after SLN mapping.

METHODS

We performed a retrospective analysis of patients with endometrial cancer undergoing a laparoscopic NIR-ICG SLN mapping followed by a systematic pelvic and para-aortic lymphadenectomy. Inclusion criteria were a grade 3 endometrial cancer or a high-risk histology (papillary serous, clear cell carcinoma, carcinosarcoma, and neuroendocrine carcinoma) and a completion pelvic and para-aortic lymphadenectomy to the renal vessels after SLN mapping. Overall and bilateral detection rates, sensitivity, NPV, and FN rates were calculated.

RESULTS

From December 2012 until January 2017, 42 patients fulfilled inclusion criteria. Overall and bilateral detection rates were 100 and 90.5%, respectively. Overall, 23.8% of the patients had lymph node metastases. In one patient, despite negative bilateral pelvic SLNs, a metastatic non-SLN-isolated para-aortic metastasis was detected. This NSLN was clinically suspicious and sent to frozen section analysis during the surgery. FN rate, sensitivity, and NPV were 10, 90, and 97.1%, respectively. For the SLN mapping algorithm, FN rate, sensitivity, and NPV were 0, 100, and 100%, respectively.

CONCLUSIONS

Laparoscopic NIR-ICG SLN mapping in high-risk endometrial cancer patients has acceptable sensitivity, FN rate, and NPV.

Is Tumor Size Really Important for Prediction of Lymphatic Dissemination in Grade 1 Endometrial Carcinoma With Superficial Myometrial Invasion?

OBJECTIVES

Selection of patients with endometrioid endometrial cancer (EEC), in whom systematic lymph node dissection (LND) is indicated, is an important part of management to maintain optimal oncological outcomes, while avoiding unnecessary morbidities. According to the current approach, LND is recommended for the patients with International Federation of Gynecology and Obstetrics (FIGO) grade 1 to 2 tumors and a primary tumor diameter (PTD) greater than 2 cm, even with myometrial invasion (MMI) of less than 50%. We aimed to determine incidence of LN metastasis in this particular group of patients with grade 1 tumors, superficial MMI, and a PTD greater than 2 cm.

MATERIALS AND METHODS

This study only focused on women with FIGO grade 1 EEC having less than 50% MMI. Therefore, women with grade 2 or 3 tumors were excluded, as well as patients with 50% or greater MMI. We also excluded women with macroscopic extrauterine disease, as well as patients with cervical stromal involvement. Patients were divided into subgroups with regard to PTD; group 1 was composed of patients with PTD of 20 mm or less, whereas group 2 was composed of patients with PTD greater than 20 mm. All clinical and pathological variables were compared between the groups.

RESULTS

Final pathology reports of 484 women with EEC who underwent surgical staging were analyzed. Among these women, there were 123 women in group 1 (PTD ≤ 20 mm) and 120 women in group 2 (PTD > 20 mm), with FIGO grade 1 tumors and superficial MMI. The median number of total LNs removed was 54 (range, 20-151). There were no women with pelvic and/or para-aortic LN metastasis in group 2, as well as in group 1.

CONCLUSIONS

Our results suggest that lymphadenectomy may be omitted in women with FIGO grade 1 EEC having superficial MMI regardless of PTD. Deferral of systematic LND in this subgroup of patients may lead to reductions in costs and surgical morbidity.

Does Obesity Affect Pathologic Agreement of Initial and Final Tumor Grade of Disease in Endometrial Cancer Patients?

OBJECTIVES

The objectives of this study were to compare preoperative and postoperative tumor grade to determine if surgical staging decisions for endometrial cancer based on preoperative biopsy are feasible and whether obesity affects the agreement.

METHODS

A retrospective cohort study of women with endometrial cancer between January 2010 and December 2011 was performed. Demographics, stage of final pathology, biopsy method, preoperative and postoperative tissue grade, and histology were abstracted and stratified by patient body mass index (obese ≥30 kg/m and nonobese <30 kg/m). Patients with incomplete records or uterine sarcoma were excluded. The agreement between preoperative and postoperative tumor grade for all patients and in obese and nonobese patients was determined using weighted κ statistics.

RESULTS

Four hindered forty-five patients were included: 161 nonobese patients and 284 obese patients. The proportion of preoperative sampling via office biopsy and dilation and curettage was similar in each cohort. Overall, the agreement between preoperative and postoperative pathology was only fair (weighted κ = 0.21). Stratified by body mass index, the agreement between preoperative and postoperative grade remains fair in obese and slight in nonobese patients (weighted κ = 0.21 and 0.19, respectively). Substantial increases in tumor grade from preoperative to postoperative pathologic specimens occurred in both cohorts.

CONCLUSIONS

Obesity does not appear to significantly alter the correlation between preoperative biopsy and final tumor grade. With only fair correlation between preoperative and postoperative pathologic evaluation, utilization of preoperative biopsy pathology results as a triage tool for surgical staging should be avoided. However, the discordance between preoperative and postoperative pathology in favor of a higher grade on final pathology in both groups may cause some surgeons to favor staging.

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.

The detection of sentinel lymph nodes in laparoscopic surgery can eliminate systemic lymphadenectomy for patients with early stage endometrial cancer

Background

The examination of a sentinel lymph node (SLN), where lymph node metastasis first occurs, may be advocated as an alternative staging technique. The aim of this study was to evaluate the feasibility and detection rates of an SLN biopsy in patients with endometrial cancer.

Study design

Two hundred and eleven patients with endometrial cancer underwent an SLN biopsy at hysterectomy using three kinds of tracers including 99m-technetium-labeled tin colloid (^99mTc), indigo carmine and indocyanine green. Factors related to the side-specific detection rate, sensitivity and false negative rate were analyzed.

Results

The detection rates of the SLN biopsy using ^99mTc, indigo carmine and indocyanine green were 77.9, 17.0 and 73.4%, respectively. The detection rate was lower in elderly patients (≥60 years) (67.9 vs 89.2%, p < 0.01), patients with >50% myometrial invasion (68.3 vs 85.2%, p < 0.01), patients with high-grade tumors (69.5 vs 84.9%, p < 0.01) and patients who underwent laparotomy (71.2 vs 84.9%, p < 0.01). There were no significant differences in body mass index. The sensitivity was not significantly different in any factor. However, the false negative rate was higher in patients with > 50% myometrial invasion (11.5 vs 1.2%, p < 0.01), high-grade tumors (13.3 vs 0.8%, p < 0.01) and who underwent laparotomy (12.2 vs 0.4%, p < 0.01).

Conclusion

Patients who underwent laparoscopy with < 50% myometrial invasion and low-grade tumors not only have higher detection rates, but also have lower false negative rates. These patients may avoid systemic lymphadenectomy according to the status of the SLN biopsy.

Intraoperative Pathologic Consultation on Hysterectomy Specimens for Endometrial Cancer: An Assessment of the Accuracy of Frozen Sections, "Gross-Only" Evaluations, and Obtaining Random Sections of a Grossly "Normal" Endometrium

OBJECTIVES

Pathologic intraoperative consultation (IOC) is a common approach for segregating the subset of patients with endometrial cancer who likely require a lymphadenectomy.

METHODS

We evaluate factors related to the performance and value of IOC, including the accuracy of frozen sections, "gross-only examinations," and obtaining random sections when a gross lesion is not apparent.

RESULTS

IOC was performed by gross examination only in 17 (8%) of 250 cases, the specificity and negative predictive value of which in diagnosing cancer were 100% and 85%, respectively. Among the 64 cases wherein a gross lesion was not apparent and random sections were examined, a final diagnosis of carcinoma was rendered in 20, of which only three (15%) had a diagnosable malignancy on the random section. The frozen-section/final diagnosis concordance was 80% for tumor grade. Determining the depth of myometrial invasion was problematic, with 36% underestimation and 2.6% overestimation.

CONCLUSIONS

Obtaining random sections in the absence of a gross lesion has no significant benefit, and a negative result is likely to provide inaccurate data to the surgeon. Frozen-section analyses are a generally reliable tool to determine "low-risk" pathologic parameters that were evaluated herein when a gross lesion is present.

Lymph node dissection in atypical endometrial hyperplasia

Objective:

The rate of concomitant endometrial carcinoma in patients with atypical endometrial hyperplasia is high. We aimed to investigate the role of lymphadenectomy in deciding adjuvant treatment in patients with concomitant atypical endometrial hyperplasia and endometrial carcinoma.

Material and Methods:

Women with atypical endometrial hyperplasia were enrolled in this retrospective study. Lymph node dissection was performed in only some patients who gave informed consent if their surgeon elected to do so, or if the intraoperative findings necessitated. The final histopathologic evaluations of surgical specimens were compared with endometrial biopsy results.

Results:

Eighty eligible patients were evaluated. Seventy-two (90%) patients had complex hyperplasia with atypia, and 8 (10%) patients had simple hyperplasia with atypia. Hysterectomy and bilateral salpingo-oophorectomy were performed to all patients; 37 also underwent lymph node dissection. Lymph node dissection was extended to the paraaortic region in 9 of 37 patients. The concomitant endometrial carcinoma rate was 50%. Two patients had lymph node metastasis. Among 40 cases of carcinoma, 17 had deep myometrial invasion and/or cervical or ovarian involvement or grade 2 tumors with superficial myometrial invasion on hysterectomy specimens; 27.5% of all carcinomas were stage Ib or higher.

Conclusion:

The concomitant endometrial carcinoma rate was high in patients with atypical endometrial hyperplasia. Nearly half of these patients had risk factors for extrauterine spread. Lymph node dissection might be helpful to decide adjuvant treatment.

Assessment of the Intraoperative Consultation Service Rendered by General Pathologists in a Scenario Where a Well-Defined Decision Algorithm Is Followed

OBJECTIVES

Intraoperative consultation (IOC) remains an area of general practice even within subspecialized pathology departments. This study assesses the IOCs rendered in a general pathology setting where surgeons integrate these results in a well-defined algorithm, developed with the input of specialized pathologists.

METHODS

The surgical decisions to perform lymphadenectomy in patients with endometrial adenocarcinoma operated on at our institution between January 2003 and June 2015 as a result of the IOC assessment of tumor size, histologic grade, and depth of invasion in the hysterectomy specimen were analyzed.

RESULTS

Frozen section (FS) was examined in 801 cases. In comparison to permanent section analysis, FS International Federation of Gynecology and Obstetrics (FIGO) grade had an overall accuracy of 0.95 (95% confidence interval [CI], 0.93-0.98). The FS depth of invasion had an overall accuracy of 0.92 (95% CI, 0.89-0.94). FIGO grade was not documented in 47.8%, the depth of myometrial invasion in 45.2%, and tumor size in 41.8% of the pathology reports.

CONCLUSIONS

The high omission rate of the needed parameters by the general pathologists would question their overall understanding of the paradigm shift intended by this algorithm. Possible explanations of this phenomenon and potential solutions are discussed.

Intraoperative Ex Vivo High-Resolution Sonography: A Novel Technique for the Assessment of Myometrial Invasion in Endometrial Cancer

OBJECTIVE

This study aims to assess the diagnostic performance of a novel intraoperative ex vivo ultrasonography technique in determining deep myometrial invasion (MI) in patients with apparently low-risk endometrial cancer (EC).

METHODS

This prospective study included patients with type I EC who underwent staging laparotomy at Hacettepe University Hospital from December 2011 to September 2014. After hysterectomy, a radiologist with special training in gynecology examined the uterus ex vivo using a 12-MHz superficial linear probe. The specimen was sent for intraoperative frozen section (FS) analysis. The results were compared with permanent section reports.

RESULTS

In total, 45 female patients were eligible for analysis. Intraoperative ex vivo high-resolution sonography (IEVHS) correctly assessed depth of MI in 39 of 45 cases (86.6%) and overestimated it in 5 cases (11.1%). Only 1 case with deep infiltration was underestimated by IEVHS as invasion of less than one half of the myometrium. Frozen section correctly identified depth of MI in 41 of 46 cases (91.1%), overestimated it in 1 case (2.2%), and underestimated it in 3 cases (6.6%). The sensitivity, specificity, positive predictive value, and negative predictive value of IEVHS and FS for assessment of deep MI were 87.5%, 86.4%, 58.3%, and 96.9%, and 62.5%, 97.3%, 83.3%, and 92.3%, respectively.

CONCLUSIONS

Intraoperative ex vivo high-resolution sonography is a novel technique for assessing MI in EC. Its high sensitivity for deep MI could be useful as an adjunct to FS (enabling pathologists to obtain targeted FS slices) and could improve the accuracy of FS.

Endometrial and cervical cancer patients with multiple sentinel lymph nodes at laparoscopic ICG mapping: How many are enough?

PURPOSE

The adoption of a sentinel lymph node (SLN) algorithm and the presence of high bilateral detection rates have been associated with increased accuracy of SLN mapping in cervical and endometrial cancer patients. In this context, the significance of the number of SLNs removed has not yet been investigated. The aim of this study was to evaluate (a) whether or not a higher SLN removal count is associated with a reduced false-negative rate and (b) which clinical factors correlate with the number of SLNs removed.

METHODS

Patients with cervical or endometrial cancer who underwent SLN mapping with bilateral SLN detection followed by lymphadenectomy were evaluated retrospectively. On the basis of the mean number of the SLNs removed, the patients were divided in two groups: Group 1 included patients with up to 3 SLNs removed and Group 2 included patients with more than 3 SLNs removed. Factors predicting a higher SLN count were evaluated using univariate and multivariate analysis.

RESULTS

Eighty-four patients met the inclusion criteria. The two groups consisted of 42 patients each and differed only by the median SLN count. Two endometrial cancer patients in Group 1 had false-negative pelvic SLNs and isolated para-aortic metastases; no false-negative SLNs were recorded in Group 2 (p = n.s.). The results of multivariate analysis indicted that the number of SLNs removed was influenced only in cases where the operating surgeon had performed more than 20 laparoscopic ICG SLN mappings.

CONCLUSIONS

A higher SLN count does not seem to increase the accuracy of SLN mapping in cervical and endometrial cancer patients.

Assessment of the Role of Intraoperative Frozen Section in Guiding Surgical Staging for Endometrial Cancer

Objective

The aim of this study was to assess the role of intraoperative frozen section (FS) in guiding decision making for surgical staging of endometrioid endometrial cancer (EC).

Methods

Medical records were collected retrospectively on 112 patients with endometrioid EC, who underwent total hysterectomy and bilateral salpingo-oophorectomy at the University of Arizona Medical Center from January 1, 2010, to December 31, 2014. Only patients with endometrioid adenocarcinoma, grade 1, less than 50% myometrial invasion, and tumor size less than 2 cm determined by intraoperative FS omitted lymphadenectomy; otherwise, surgical staging was performed with lymph node dissection. The FS results were compared with the permanent paraffin sections (PSs) to assess the diagnostic accuracy.

Results

The concordance rate of different variables between FS and PS in EC was 100%, 89.3% (100/112), 97.3% (109/112), and 95.5% (107/112), respectively, with respecting to histological subtype, grade, myometrial invasion, and tumor size. Diagnostic accurate rate of combined risk factors deciding surgical staging at the time of FS was 95.5% (107/112), and the discordance rate of all risk factors considered between FS and PS was 4.5%, resulting 3 cases (2.7%) undertreated and 2 cases (1.8%) overtreated.

Conclusions

Despite nonideal FS evaluation, intraoperative FS diagnosis for EC is highly reliable by providing guidance for the intraoperative decisions of surgical staging at our institution, and such guidelines may be referenced by the institutions with sufficient gynecologic pathology expertise.