Clinical value of immunohistochemically detected lymphovascular invasion in endometrioid endometrial cancer

Practical guidance for assessing and reporting lymphovascular space invasion (LVSI) in endometrial carcinoma

Lymphovascular space invasion (LVSI) is an important prognostic parameter in endometrial carcinoma (EC) and has gained increasing interest in recent years due to an expanding body of evidence of its independent prognostic value, especially when the presence of LVSI is quantified. A key strength of LVSI as a prognostic factor is that it can be detected on routine microscopic examination, without ancillary tests, and thus can be used in low-resource settings. A weakness, however, is the lack of uniformly applied criteria for assessment and quantification of LVSI, resulting in interobserver variation in diagnosis. This is confounded by artefacts and other morphological features that may mimic LVSI (commonly referred to as pseudo-LVSI). Despite these issues, multiple studies have shown that LVSI is strongly associated with lymph node (LN) metastasis and is an independent risk factor for LN recurrence and distant metastasis. Consequently, the presence of substantial/extensive LVSI has become an important consideration in formulating adjuvant treatment recommendations in patients with EC, and this has been incorporated in the recent International Federation of Gynecology and Obstetrics (FIGO) 2023 staging system. Herein, we review the current literature on LVSI in EC and discuss its role as a prognostic marker, the reproducibility of LVSI assessment and distinction between LVSI and its mimics. We provide illustrations of key diagnostic features and discuss the two-tiered (none/focal versus substantial) system of LVSI classification. This work is intended to provide guidance to practising pathologists and unify the approach towards LVSI assessment in EC.

Lymphovascular space invasion in endometrial carcinoma: Tumor size and location matter

OBJECTIVE

To analyze histological factors possibly associated with lymphovascular space invasion (LVSI) and to determine which of those can act as independent surrogate markers.

METHODS

Retrospective cohort study performed between January 2001 and December 2014. LVSI was defined as the presence of tumor cells inside a space completely surrounded by endothelial cells. Risk factors evaluated included myometrial invasion, tumor grade, size, location, and cervical invasion. Univariate logistical regression models were applied to study any possible association of LVSI with these factors. Values were adjusted by multivariate logistic regression analysis.

RESULTS

A total of 327 patients with endometrial carcinoma treated in our Centre were included. LVSI was observed in 120 patients (36.7%). Lower uterine segment involvement (OR 5.21, 95% CI:2.6-10.4, p < 0.001) and size ≥2 cm (OR 2.62, 95% CI: 1.14-6.1, p < 0.001) were independent factors for LSVI in multivariate analysis. In univariate analysis, LVSI was a surrogate marker in type 1 tumors with deep myometrial invasion (IB, 51.9% vs. IA, 16.0%; p < 0.001), grade 3 (G3 55.8% vs. G1 16.2%; p < 0.001), size ≥2 cm (37.9% vs. 16.1%, p = 0.005), those with involving the lower segment of the uterus (58.9% vs. 22.5%, p < 0.001) and/or with cervical stromal invasion (65.4% vs. 26.1%, p < 0.001), and in type 2 tumors (61.5% vs. 30.5%, p < 0.001). The use of uterine manipulator did not increase the rate of LVSI (35.5% vs. 40.5%, p = 0.612) as compared to no manipulator use.

CONCLUSIONS

Size ≥2 cm and involvement of the lower uterine segment are independent factors for LSVI, in type 1 tumors, which can be used for surgical planning. LVSI is also more common in type 1 tumors with deep myometrial invasion, grade 3 and/or cervical stromal invasion, and also in type 2 tumors. The use of a uterine manipulator does not increase LVSI.

Pathologic Prognostic Factors in Endometrial Carcinoma (Other Than Tumor Type and Grade)

Although endometrial carcinoma (EC) is generally considered to have a good prognosis, over 20% of women with EC die of their disease, with a projected increase in both incidence and mortality over the next few decades. The aim of accurate prognostication is to ensure that patients receive optimal treatment and are neither overtreated nor undertreated, thereby improving patient outcomes overall. Patients with EC can be categorized into prognostic risk groups based on clinicopathologic findings. Other than tumor type and grade, groupings and recommended management algorithms may take into account age, body mass index, stage, and presence of lymphovascular space invasion. The molecular classification of EC that has emerged from the Cancer Genome Atlas (TCGA) study provides additional, potentially superior, prognostic information to traditional histologic typing and grading. This classifier does not, however, replace clinicopathologic risk assessment based on parameters other than histotype and grade. It is envisaged that molecular and clinicopathologic prognostic grouping systems will work better together than either alone. Thus, while tumor typing and grading may be superseded by a classification based on underlying genomic abnormalities, accurate assessment of other pathologic parameters will continue to be key to patient management. These include those factors related to staging, such as depth of myometrial invasion, cervical, vaginal, serosal surface, adnexal and parametrial invasion, and those independent of stage such as lymphovascular space invasion. Other prognostic parameters will also be discussed. These recommendations were developed from the International Society of Gynecological Pathologists Endometrial Carcinoma project.

Clear Cell Carcinoma of the Endometrium: Evaluation of Prognostic Parameters in a Multi-institutional Cohort of 165 Cases

OBJECTIVES

Clear cell carcinoma (CCC) comprises a rare yet an aggressive subtype, accounting for less than 5% of all uterine carcinomas. Several clinicopathologic features have been predictive of poor prognosis; however, data remain controversial. The aim of this study was to evaluate the clinicopathologic features of a multi-institutional cohort of endometrial CCC in order to identify which, if any, have prognostic significance.

METHODS

Retrospective review of endometrial CCC diagnosed between 1995 and 2012 at 3 institutions was conducted to evaluate clinicopathologic parameters: age, race, tumor size, stage, myometrial invasion (MI), lymphovascular invasion, lymph node and adnexal involvement, adjuvant therapy, and outcomes. Data were analyzed using Fisher exact, Cox regression, and Kaplan-Meier analyses.

RESULTS

Patients' ages ranged from 36 to 90 years (median, 67 years). The median tumor size was 3.6 cm. Inner-half MI was present in 44%, lymphovascular invasion in 34%, adnexal involvement in 16%, and lymph node metastasis in 30% of cases. Fifty-eight percent of the patients presented with early-stage disease. The 5-year overall survival (OS) was 58%. Shorter disease-free interval (DFI) was significantly associated with older age at diagnosis (>70 years), advanced-stage disease, adnexal involvement, and deep MI (P = 0.005, P = 0.001, P = 0.001, and P = 0.003, respectively). Patients who received adjuvant chemotherapy had a significantly worse DFI and 5-year OS (P = 0.001 and P = 0.001, respectively). A significantly shorter 5-year OS was noted with advanced stage (III-IV) and presence of adnexal involvement (P = 0.001 and P = 0.021, respectively). On Cox regression analysis, advanced-stage disease, older age, and adnexal involvement were significant independent predictors of worse DFI (P = 0.001, P = 0.005, and P = 0.019, respectively), whereas inner-half MI was a significant independent predictor of longer DFI (P = 0.004). Adjuvant radiotherapy alone was a significant independent predictor of better 5-year OS (P = 0.012).

CONCLUSIONS

In our series of endometrial CCC, older age at diagnosis, advanced stage, deep MI, and adnexal involvement were independent poor prognostic factors. Adjuvant radiotherapy had a significant positive impact on 5-year OS.

Type of vascular invasion in association with progress of endometrial cancer

Vascular invasion (VI) is a well-established marker for lymph node metastasis and outcome in endometrial cancer. Our study explored whether specific types of VI, defined as lymphatic (LVI) or blood vessel invasion (BVI), predict pattern of metastasis. From a prospectively collected cohort, we conducted a case-control study by selecting three groups of endometrial cancer patients (n = 183): 52 with positive lymph nodes at primary surgery, 33 with negative nodes at primary surgery and later recurrence and death from disease, and 98 with negative nodes and no recurrence. All patients underwent hysterectomy with lymphadenectomy. Immunohistochemical staining with D2-40 and CD31 antibodies was used to differentiate between BVI and LVI. By immunohistochemical staining, detection of VI increased from 24.6 to 36.1% of the cases. LVSI was significantly more often seen in patients with positive lymph nodes compared with patients with negative nodes (p = 0.001). BVI was significantly more often seen in node-negative patients with recurrence compared with node-negative patients without recurrence (p = 0.011). In multivariable analysis, BVI, age, and tumor grade were predictors separating patients with and without recurrence. Lymph node-positive patients showed more often LVI compared with lymph node-negative patients, while BVI seems to be a predictor for recurrent disease.

Histological features associated with occult lymph node metastasis in FIGO clinical stage I, grade I endometrioid carcinoma

AIMS

Lymph node involvement affects prognosis/treatment in endometrial carcinoma patients. We assessed various histological features associated with nodal metastasis in patients with grade I, stage I endometrial endometrioid carcinoma (EEC).

METHODS AND RESULTS

Eighteen stage I EECs with occult positive lymph nodes and 36 controls were assessed for depth of myoinvasion; microcystic, elongated and fragmented (MELF) pattern of myometrial invasion; lymphovascular invasion (LVI); and epithelial metaplasia. Nodal metastases were subclassified as isolated tumour cells (ITCs; ≤0.2 mm), micrometastasis (>0.2 mm and <2 mm), or macrometastasis (≥2 mm). Node-positive cases had significantly higher rates of LVI (P < 0.001) and MELF invasion (P = 0.003) on univariate analysis. Only LVI was associated significantly with nodal metastasis on multivariate analysis (P = 0.002). Tumours with MELF invasion demonstrated reduced E-cadherin expression. Macrometastases were identified in seven cases (39%) with or without micrometastasis/ITCs. Eight (44%) contained only ITCs. Eleven (61%) had histiocyte-like nodal metastases. Biopsy material from four of six (67%) and five of 17 (29%) cases with and without nodal metastasis showed detached eosinophilic tumour cell buds. Of the former, three were associated with histiocyte-like nodal metastases - a feature absent in biopsies without tumour budding.

CONCLUSIONS

Lymph nodes from grade I EEC exhibiting cellular budding or LVI should be examined for occult metastases, especially in the form of histiocyte-like cells.

The Grading of Lymphovascular Space Invasion in Epithelial Ovarian Carcinoma

Introduction:

To assess the prognostic value of lymphovascular space invasion (LVSI) in epithelial ovarian carcinoma.

Methods:

We reexamined single representative hematoxylin and eosin-stained sections of 66 patients with epithelial ovarian carcinoma to identify LVSI. A 4-grade system was used to classify LVSI: absent (no LVSI), mild (1-2 foci of LVSI), moderate (3-8 foci of LVSI), and severe (≥9 foci of LVSI). We investigated the possible associations between the grade of LVSI and clinicopathologic factors.

Results:

Lymphovascular space invasion was present in 36 patients (54.5%) and absent in 30 (45.5%). Statistical analysis indicated that LVSI was significantly associated with advanced clinical stage, poor histological grade, and lymph node metastasis. Follow-up studies indicated that the disease-free survival time for patients without LVSI was significantly longer than that for patients with moderate LVSI (P = 0.01) and severe LVSI (P = 0.001). The overall survival (OS) time for patients with moderate or severe LVSI was significantly shorter than that for patients with mild or no LVSI. The grade of LVSI was found to be significantly associated with OS (P = 0.004). The grade of LVSI showed poor correlation with disease-free survival and OS.

Conclusions:

The grade of LVSI is an important predictive factor for disease recurrence and poor survival of patients with epithelial ovarian carcinoma.

Clinical value of immunohistochemically detected lymphatic and vascular invasions in clinically staged endometrioid endometrial cancer

BACKGROUND

A novel technique to differentiate lymphatic from vascular invasion and to assess the clinicopathological significance in patients with early endometrial cancer.

METHODS

Dual immunohistochemical techniques against pancytokeratin epithelial cell marker (PCK), D6 lymphatic endothelial marker, and CD31 nonspecific endothelial marker were deployed for differentiation. Seventy-seven patients were included with a median follow-up of 161 months. Tumors with positive evidence of lymphovascular space invasion on PCK-CD31 immunohistochemistry and absence of lymphatic space invasion on PCK-D6 were regarded as cases with vascular space invasion only.

RESULTS

Significant association between depth of myometrial invasion, recurrence rate, and hematoxylin and eosin that detected lymphovascular space invasion were noted (P < 0.0001 and P = 0.009, respectively). The 5-year recurrence-free survival was 45% for the group with hematoxylin and eosin evidence of lymphovascular space invasion compared with 89% for the group without (P = 0.0014). Pancytokeratin epithelial cell marker-D6 dual immunostaining detected lymphatic space invasion in 22 (29%) patients. There was significant association between lymphatic space invasion and depth of myometrial invasion (P = 0.046). Lymphatic space invasion detected on immunohistochemistry was present in 8 (72%) of 11 patients with recurrent disease. Of the remaining 49 patients with no evidence of recurrent disease, only 11 (22%) had presented with lymphatic space invasion. Positive association between tumor recurrence rate and lymphatic space invasion was noted (P = 0.003). The 5-year recurrence-free survival was 53% for the group with lymphatic invasion compared with 93% for the group without. This difference was similarly shown to be of significance (P = 0.0009). There were no apparent association between immunohistochemically detected lymphovascular or vascular space invasion and any clinicopathological factor.

CONCLUSIONS

Lymphatic space invasion detected by using dual immunostaining is of significant value in identifying high-risk patients.

Cervical biopsy and excision procedure specimens lack sufficient predictive value for lymph-vascular space invasion seen at hysterectomy for cervical cancer

OBJECTIVE

The purpose of this study was to determine whether lymph-vascular space invasion (LVSI) that is discovered in cervical biopsy and excision specimens is associated with LVSI in the hysterectomy specimen of patients with cervical cancer.

STUDY DESIGN

A retrospective pathologic review to determine the presence of LVSI in cervical biopsy specimens, cold-knife cone biopsy (CKC biopsy), and loop electrical excision procedure (LEEP) specimens that contained cervical cancer was performed if subsequent hysterectomy results were available for review. Data were analyzed with chi-square analysis testing.

RESULTS

One hundred six patients were identified. The negative predictive value of the biopsy is lower at 0.45 than either the CKC biopsy (0.83) or LEEP (0.57); however, the positive predictive value (0.83) is higher than either CKC biopsy (0.50) or LEEP (0.75). LVSI, when present in cervical biopsy (odds ratio, 4.13; 95% CI, 0.414-98.446), CKC biopsy (odds ratio, 4.8; 95% CI, 0.542-46.280), and LEEP (odds ratio, 4.0; 95% CI, 0.439-43.793) specimens, is associated with a statistically insignificant increased risk of LVSI in the hysterectomy specimen.

CONCLUSION

Cervical biopsy and excision specimens lack sufficient negative predictive value for the detection of LVSI in the hysterectomy specimen.

Clinical value of immunohistochemically detected lymphovascular space invasion in early stage cervical carcinoma

BACKGROUND

This study investigates the clinical significance of lymphovascular space invasion (LVSI) as detected by hematoxylin and eosin (LVSI-H&E) and immunohistochemistry (LVSI-IHC) in early stage cervical carcinoma.

METHODS

Single representative sections from 97 patients with early stage squamous cell cervical cancer were immunostained with pancytokeratin and CD31 endothelial cell marker antibodies. The H&E sections and their corresponding immunostained sections were reexamined to identify LVSI. Associations between LVSI with clinicopathological factors were sought.

RESULTS

Overall, LVSI was present in 29 (29.9%) and absent in 68 (70.1%) by IHC, as compared with 18 cases (18.6%) and 79 cases (81.4%), respectively, by H&E. Statistical analysis revealed a significant association between LVSI-H&E and nodal metastasis (P = .004). Follow-up data were available for 76 patients. The median follow-up period was 64 months. During follow-up, 7 of 24 patients with recurrent disease had evidence of LVSI-H&E as opposed to 3 of 52 cases with no recurrence. There was a significant association between tumor recurrence and LVSI-H&E (P = .009). The 5-year recurrence-free survival was 30% for the group with LVSI-H&E compared with 73% without. There was a significant difference in the recurrence-free survival between the two groups (P = .002). In contrast LVSI-IHC was found to be associated with no pathological factors, and survival analysis revealed no statistically significant association with recurrence or survival.

CONCLUSION

LVSI-H&E in early stage cervical cancer remains an important predictive factor of recurrent disease and reduced disease-free interval. Immunohistochemically detected LVSI is a common event and seems to be of no clinical value.

Lymphangiogenesis of normal endometrium and endometrial adenocarcinoma

BACKGROUND

Information about lymphatics and lymphangiogenesis in the human endometrium is limited. We investigated the distribution of endometrial lymphatic vessels during the normal menstrual cycle and in association with endometrial adenocarcinoma and investigated the expression of lymphangiogenic growth factors, vascular endothelial growth factor (VEGF)-C, VEGF-D and VEGF receptor-3 (VEGF-R3).

METHODS AND RESULTS

Full thickness uterine samples (n = 23 proliferative; n = 23 secretory) and endometrial adenocarcinoma samples (n = 7 grade I; n = 10 grade III) were collected for the study and analysed by immunohistochemistry and western blotting. Lymphatic vessels of the functionalis were significantly reduced compared with basalis (P = 0.001) across the menstrual cycle with lymphatics of the basalis sometimes intimately associated with spiral arterioles. Lymphatic vessels of endometrial adenocarcinomas were located intra-tumoural and peri-tumoural with significant increases in the peri-tumoural lymphatic vessels compared with normal basalis (P = 0.02). Interestingly, high-grade adenocarcinoma vessels containing tumour emboli demonstrated a mixed blood/lymphatic endothelial cell phenotype. VEGF-C and VEGF-D were immunolocalized in glandular epithelium and some stromal cells with the staining intensity of this localization increasing in endometrial adenocarcinoma. Protein analysis identified VEGF-C (58, 41, 31 and 21 kD) and VEGF-D (56, 41, 31 and 21 kD) and VEGF-R3 (148 and 65 kD) peptides in normal endometrium, with significant increases in several of these peptides for VEGF-C and VEGF-D and no changes in protein expression for VEGF-R3 in endometrial adenocarcinoma.

CONCLUSION

Endometrial lymphatics are significantly reduced in the functionalis, and increases in endometrial adenocarcinoma peri-tumoural lymphatics are associated with increases in VEGF-C and VEGF-D peptides.

Statistical analysis of pathologic risk factors for intramyometrial lymphvascular space involvement in myoinvasive endometrial carcinoma

In a retrospective study using univariate analysis, we identified tumor type (nonendometrioid vs endometrioid), depth of myoinvasion (MI), mode of MI (infiltrative vs cohesive), and direct anatomic invasion of the cervical wall from the isthmus as significant positive risk factors for intramyometrial lymphvascular space involvement (LVSI). On multivariate analysis, tumor grade, depth of MI, and mode of MI retained their significance. We created a grid for the relative risks of LVSI with respect to these variables individually or in combination. We suggest that our indirect estimate of the risk of LVSI can help in assessing prognosis and determining the need for adjuvant therapy whenever LVSI is important in clinical decision making, but its pathologic diagnosis is uncertain.

Assessment of Uterine Wall Thickness and Position of the Vascular Plexus in the Deep Myometrium: Implications for the Measurement of Depth of Myometrial Invasion of Endometrial Carcinomas

Accurate discrimination between FIGO stages IB and IC endometrial carcinomas has important prognostic and therapeutic implications, but depth of invasion as a percentage of myometrial thickness can be difficult to ascertain. In such cases, pathologists often presume that infiltration that reaches the arcuate vascular plexus (AVP) in the myometrium indicates >50% myoinvasion. The further assumption is sometimes made that the anterior and posterior uterine walls are of the same thickness. To our knowledge, neither supposition is based on published data. We performed a prospective study of myometrial thickness and the position of the AVP in 50 normal uteruses from patients aged 27 to 84 years. Myometrial thickness varied inversely with age (p < 0.0001); however, anterior and posterior wall myometrial thickness did not differ significantly in the cohort as a whole (p = 0.059) and in individual cases was highly correlated (p < 0.0001). The position of the AVP was variable. On average, its inner limit was situated at a depth of 47.3% of the thickness of the myometrium in both uterine walls, but the position varied between individuals and sometimes differed considerably between the anterior and posterior walls of the same uterus. The position of the AVP did not differ significantly with age. We conclude that carcinomatous infiltration well into or through the AVP usually signifies >50% myoinvasion; however, if infiltration barely extends into the AVP, the depth of invasion should be calculated with reference to the thickness of the myometrium in the opposite uterine wall.

Intravaginal brachytherapy alone for intermediate-risk endometrial cancer

PURPOSE

Despite the results of the Gynecologic Oncology Group trial No. 99 (GOG#99), some unanswered questions still remain about the role of adjuvant radiotherapy (RT) for intermediate-risk endometrial cancer. First, can intravaginal brachytherapy (IVRT) alone substitute for external beam RT but without added morbidity? Second, is the high-risk (HR) definition from GOG#99 a useful tool to predict pelvic recurrence specifically? The purpose of this study was to try to answer these questions in a group of patients with Stage IB-IIB endometrial carcinoma treated with high-dose-rate (HDR) IVRT alone.

METHODS AND MATERIALS

Between November 1987 and December 2002, 382 patients with Stage IB-IIB endometrial carcinoma were treated with simple hysterectomy followed by HDR-IVRT alone at our institution. Comprehensive surgical staging (CSS), defined as pelvic washings and pelvic/paraaortic lymph node sampling, was performed in 20% of patients. The mean age was 60 years (range, 29-92 years). Lymphovascular invasion (LVI) was present in 14% of patients. The median HDR-IVRT dose was 21 Gy (range, 6-21 Gy), given in three fractions. Complications were assessed in terms of late Radiation Therapy Oncology Group (Grade 3 or worse) toxicity of the GI tract, genitourinary GU tract, and vagina.

RESULTS

With a median follow-up of 48 months, the 5-year vaginal/pelvic control rate was 95% (95% confidence interval [CI], 93-98%). On multivariate analysis, a poor vaginal/pelvic control rate correlated with age > or =60 years old (relative risk [RR], 3, 95% CI, 1-12; p = 0.01), International Federation of Gynecology and Obstetrics (FIGO) Grade 3 (RR, 9, 95% CI, 2-35; p = 0.03), and LVI (RR, 4, 95% CI, 1-13; p = 0.051). The depth of myometrial invasion and CSS, however, were not significant. With regard to pelvic control specifically, the presence of GOG#99 HR features did not affect the pelvic control rate. The 5-year rate for HR patients was 96% (95% CI, 90-100%) vs. 96% (95% CI, 94-99%) for those without HR disease (p = 0.48). Even when the CSS effect was taken into account, the influence of HR features on pelvic control was still not significant (p = 0.51). In contrast, pelvic control was significantly influenced when patients were grouped according to CSS and stage/grade substages. For those with Stage IB Grade 3-IIB and no CSS, the 5-year pelvic control rate was 86% compared with 97% for those with Stage IB Grade 3-IIB and CSS, 97% for Stage IB, Grade 1-2 without CSS, and 100% for those with Stage IB, Grade 1-2 and CSS (p = 0.027). The 5-year disease-free survival rate was 93% (95% CI, 90-96%). On multivariate analysis, poor disease-free survival correlated with age > or =60 years (RR, 5; 95% CI, 1-18; p = 0.002), FIGO Grade 3 (RR 5, 95% CI 2-17; p = 0.013), and LVI (RR 3, 95% CI 1-8; p = 0.054). Unlike pelvic control, disease-free survival was significantly affected by GOG#99 HR features, with a 5-year rate of 87% (95% CI, 76-99%) vs. 94% (95% CI, 91-97%) for those without HR features (p = 0.027). The 5-year overall and disease-specific survival rate was 93% and 97%, respectively. The overall 5-year actuarial rate of Grade 3 or worse complications was 1% (95% CI, 0-2%).

CONCLUSION

Tumor grade, depth of invasion, and the use of CSS were better predictors of pelvic control than the GOG#99 HR factors. IVRT alone seemed to provide adequate tumor control with very low morbidity. Therefore, it seems prudent to consider it for intermediate-risk patients because of its superior therapeutic ratio compared with that for surgery alone or pelvic RT. Additional follow-up, however, with a larger number of patients is needed, especially for those with LVI.