MELF pattern of myometrial invasion and role in possible endometrial cancer diagnostic pathway: A systematic review of the literature

The Prognostic Value of Tumor Cell Clusters in the Fallopian Tube Lumen in Stage I Endometrioid Carcinoma

The aim of this study was to investigate the pathologic prognostic factors such as tumor cell clusters (TCCs) in the fallopian tube lumen, myometrial invasion patterns, and positive peritoneal cytology (PPC) in women with Stage I endometrial endometrioid carcinoma (EEC). From 2009 to 2020, consecutive patients with Stage I EEC who underwent hysterectomy and bilateral salpingectomy were included. The primary outcome was the recurrence-free survival (RFS) rate, and the clinicopathological factors affecting RFS were analyzed. A total of 765 patients were enrolled. Seventeen patients (2.2%) had TCC in the fallopian tube lumen, and 58 patients showed a microcystic elongated and fragmented pattern (7.6%). PPC was found in 19 patients (2.5%). The median follow-up period was 61.0 months (range: 2.0-149.7). The majority (88.6%) of patients had Stage IA EEC. The 5-year RFS and overall survival rates were 97.5% and 98.5%, respectively. In multivariate analysis for RFS, the significant prognostic factors were lymphovascular invasion (hazard ratio = 4.604; 95% CI: 1.387-15.288; P = 0.013) and grade (grade 2; hazard ratio = 4.949; 95% CI: 1.035-23.654; P = 0.045, and grade 3; hazard ratio = 5.469; 95% CI: 1.435-20.848; P = 0.013). Other pathologic factors including TCC in the fallopian tube lumen, myometrial invasion patterns, PPC, and hormonal status had no prognostic significance. TCC in the fallopian tube lumen, myometrial invasion pattern, PPC, and estrogen and progesterone receptor positivity were not significant prognostic factors in Stage I EEC. In contrast, lymphovascular invasion and grade were significant prognostic factors.

Can the microcystic, elongated and fragmented pattern of invasion influence the evaluation of the depth of myometrial invasion in low-grade endometrioid endometrial cancer using imaging techniques?

Objectives

The microcystic, elongated and fragmented pattern of invasion can be associated with an underestimation of the depth of myometrial invasion by imaging techniques. We aimed to evaluate the influence of microcystic, elongated and fragmented pattern of invasion in the diagnostic performance of transvaginal ultrasound scan and magnetic resonance imaging for the prediction of the depth of myometrial invasion in low-grade endometrioid endometrial carcinomas.

Methods

Prospective and consecutive study including all low-grade (G1-G2) endometrioid endometrial carcinomas diagnosed between October 2013 and July 2018 in a tertiary hospital. Preoperative staging was performed with transvaginal ultrasound scan and/or magnetic resonance imaging followed by surgical staging. Final histology was considered as the reference standard. Sensitivity, specificity and diagnostic accuracy for the prediction of depth of myometrial invasion was calculated for both imaging techniques. The STARD 2015 guidelines were used.

Results

A total of 136 patients were consecutively included. Transvaginal ultrasound scan was performed in 132 patients and magnetic resonance imaging in 119 patients. The diagnostic accuracy of transvaginal ultrasound scan for the prediction of depth of myometrial invasion in the microcystic, elongated and fragmented negative group (82% (95% confidence interval = 73-88)) was higher compared to the microcystic, elongated and fragmented positive group (61% (95% confidence interval = 36-83)). The diagnostic accuracy of magnetic resonance imaging was also higher in the microcystic, elongated and fragmented negative group (80% (95% confidence interval = 71-87)) compared to the microcystic, elongated and fragmented positive (47% (95% confidence interval = 21-73)).

Conclusions

In low-grade endometrioid endometrial carcinomas with a positive microcystic, elongated and fragmented pattern of invasion, the evaluation of the depth of myometrial invasion using transvaginal ultrasound scan and magnetic resonance imaging may be underestimated.

Data Set for the Reporting of Endometrial Cancer: Recommendations From the International Collaboration on Cancer Reporting (ICCR)

Endometrial cancer is one of the most common cancers among women. The International Collaboration on Cancer Reporting (ICCR) developed a standardized endometrial cancer data set in 2011, which provided detailed recommendations for the reporting of resection specimens of these neoplasms. A new data set has been developed, which incorporates the updated 2020 World Health Organization Classification of Female Genital Tumors, the Cancer Genome Atlas (TCGA) molecular classification of endometrial cancers, and other major advances in endometrial cancer reporting, all of which necessitated a major revision of the data set. This updated data set has been produced by a panel of expert pathologists and an expert clinician and has been subject to international open consultation. The data set includes core elements which are unanimously agreed upon as essential for cancer diagnosis, clinical management, staging, or prognosis and noncore elements which are clinically important, but not essential. Explanatory notes are provided for each element. Adoption of this updated data set will result in improvements in endometrial cancer patient care.

Microcystic, elongated and fragmented (MELF) pattern in endometrial carcinoma: clinicopathologic analysis and prognostic implications

To assess the clinical value of microcystic, elongated, and fragmented (MELF) pattern in Chinese patients with endometrial endometrioid carcinoma. A total of 189 patients with endometrial endometrioid carcinoma were retrospectively analyzed in Peking University Third Hospital from January 2017 to December 2019. We analyzed the association of MELF pattern with the histopathologic data and prognosis of the patients, while immunohistochemistry was performed. The frequency of MELF pattern was 17.99% (34/189). MELF pattern was associated significantly with tumor size, myometrial invasion, histological grade, International Federation of Gynecology and Obstetrics stages, lymphovascular space invasion, and lymph node metastasis. According to multivariate logistic regression analysis, lymphovascular space invasion [95% confidence interval 1.021-48.485, P = .048] was a significant predictor of lymph node involvement. However, MELF pattern was not a significant predictor (95% confidence interval 0.054-2.279, P = .400). Loss of expression for mismatch repair proteins was observed in 10 MELF + cases (29.41%) and 54 MELF- cases (34.84%), respectively. All patients were followed up for 36.8 ± 8.9 months (18-54 months). Only 1 patient with MELF pattern was diagnosed with vaginal recurrence 28 months after the surgery. MELF pattern was associated with adverse histologic findings in endometrial endometrioid carcinomas. However, MELF pattern was statistically not a valuable predictor of lymph node metastasis and it needs more studies to show whether MELF pattern has an impact on the prognosis of patients with endometrial endometrioid carcinoma. MELF pattern may be important for identifying those patients who need comprehensive staging surgery.

Clinical utility of pathology data: endometrial and tubo-ovarian carcinomas

Cancer resection specimens are usually reported using standardised proformas that consist of a list of elements, which include core (required) and non-core (recommended) items. Although all elements are generally included in the reports, the clinical importance of a particular parameter often depends on a variety of factors, including the clinical setting, local management guidelines and other pathological parameters. In this review, we briefly outline how histopathology data are used to guide management of patients with endometrial and tubo-ovarian cancers, the most common gynaecological malignancies, and provide advice as to which data elements are important in particular scenarios.

Clinicopathologic Association and Prognostic Value of MELF Pattern in Invasive Endocervical Adenocarcinoma (ECA) as Classified by IECC

Microcystic, elongated, and fragmented (MELF) pattern of myometrial invasion is correlated with lymphovascular invasion (LVI) and lymph node metastases in uterine endometrioid carcinoma but has not been described in endocervical adenocarcinoma (ECA). A total of 457 ECAs were collected, and clinical/morphologic parameters correlated with follow-up data. Potential associations between MELF pattern and age, human papillomavirus status, tumor size/grade, LVI, lymph node metastases, Silva pattern were analyzed. Statistical analyses of overall survival (OS), disease-free survival, progression-free survival (PFS) were conducted using Kaplan-Meier analysis, and compared using the Log-rank test. Of 292 ECAs analyzed, 94 (32.19%) showed MELF invasion pattern (MELF-positive). Significant statistical correlation was found between MELF-positive and tumor size (P=0.0017), LVI (P=0.007), Silva pattern (P=0.0005); age, human papillomavirus status, tumor grade, lymph node metastases did not correlate. Fifty-five of 292 patients recurred (18.83%): 18/94 (19.14%) MELF-positive, 37/198 (18.68%) MELF-negative. PFS in MELF-positive: 77.2% and 64.5% at 5 and 10 yr, respectively; PFS in MELF-negative: 82% and 68.5% at 5 and 10 yr, respectively. On multivariate analysis for PFS and other prognostic parameters, only LVI was statistically significant (P=0.001). OS in MELF-positive was 86% and 74.1% at 5 and 10 yr, respectively; OS in MELF-negative, was 89.7% and 86% at 5 and 10 yr, respectively. Median survival was worse in MELF-positive (199.8 mo) versus MELF-negative (226.1 mo); this was not statistically significant. On multivariate analysis for OS and other prognostic parameters, only tumor stage was statistically significant (P=0.002). In ECAs, MELF is not independently associated with survival. Pathologic characteristics of MELF-positive (size, LVI, Silva pattern) versus MELF-negative tumors differ significantly.

Safety and efficacy of synchronous panniculectomy and endometrial cancer surgery in obese patients: a systematic review of the literature and meta-analysis of postoperative complications

Panniculectomy combined with gynaecological surgery constitutes an alternative approach for endometrial cancer (EC) in obese patients. The present study aimed to assess the current knowledge concerning the safety and efficacy of combining panniculectomy in surgical management of EC. Four electronic databases were systematically searched for articles published up to May 2019. A total of five studies, of which two were non-comparative and three comparative, were included. Meta-analysis of complications among panniculectomy and conventional laparotomy group revealed no difference in either intra- or post-operative complication rates. Moreover, no difference was reported in surgical site complications (p=0.59), while wound breakdown rates were significantly elevated in the laparotomy group (p=0.02). Panniculectomy combined surgery for the management of EC appears to be a safe procedure and results in comparable outcomes compared with conventional laparotomy with regard to complications and improved wound breakdown rates.

POLE mutation combined with microcystic, elongated and fragmented (MELF) pattern invasion in endometrial carcinomas might be associated with poor survival in Chinese women

OBJECTIVE

POLE mutation is a prognostic marker associated with excellent outcome in endometrial carcinoma (EC). However, these EC tumors frequently have aggressive histology. The aim of this study was to determine how to integrate the implications of POLE mutations into existing risk assessment strategies and further stratify patients.

METHODS

We detected POLE mutations in a cohort of 426 ECs from Chinese women and observed their prognostic significance in terms of survival and recurrence outcomes in combination with histological and other molecular characteristics, including microcystic, elongated and fragmented (MELF) pattern invasion, histologic subtype, tumor grade, myometrial invasion and p53 protein and mismatch repair protein expression status.

RESULTS

POLE mutations were identified in 38 of 426 ECs (8.9%). The most common mutations were P286R (31.6%), V411L (15.8%) and Q453R (15.8%). We confirmed that POLE mutation was associated with improved overall survival (P = .047), although it did not show a statistically significant relationship with progression-free survival (P = .45). Interestingly, further analyses indicated that in POLE-mutant tumors, MELF pattern invasion was associated with a 15.1-fold increase in tumor recurrence or progression risk (HR = 15.1, 95%CI = 1.57-145.3, P = .018), whereas this phenomenon was not present in the POLE-wild-type subgroup (HR = 0.90, 95%CI = 0.39-2.08, P = .80). Furthermore, higher staging and deeper myometrial invasion also showed much higher risk in patients harboring POLE mutations compared with those without POLE mutations.

CONCLUSIONS

Although POLE mutation was associated with favorable overall survival, the combined consideration of POLE mutation status and established clinicopathologic factors in the risk assessment of endometrial cancer is more accurate than the consideration of clinicopathologic factors alone and might lead to precise and individualized therapeutic strategies.

The effect of myometrial invasion on prognostic factors and survival analysis in endometrial carcinoma

Background

We investigated the relationship between myometrial invasion and the prognostic factors on overall and progression free survival in endometrial carcinoma.

Methods

122 cases operated with endometrial cancer were included into the study. Progression-free survival and overall survival were evaluated according to degree of myometrial invasion. We also investigated the relationship between myometrial invasion and prognostic factors.

Results

The 5- year progression-free survival rate was 90 % in stage I, 66 % in stage II, 32 % in stage III and 60 % in stage IV. The 5- year overall survival rate was 95 % in stage I, 89 % in stage II, 49 % in stage III and 30 % in stage IV. The progression free survival and overall survival for patients with more than 50 % myometrial invasion were detected 67 % at 58 months and 66 % at 60 months, respectively. The clinicopathological variables that significantly correlated with myometrial invasion of more than 50 % were as follows: pelvic lymph node metastasis (p: 0,00029-OR: 11.2), cervical stromal invasion (p: 0008-OR:7.9), LVSI (p< 0.0001-OR: 16.5).

Conclusion

The depth of myometrial invasion is one of the most important prognostic indicators and determinants of therapy in endometrial cancer.

High Expression of Galectin-1, VEGF and Increased Microvessel Density Are Associated with MELF Pattern in Stage I-III Endometrioid Endometrial Adenocarcinoma

Background

In this study, we investigate the expression of markers of angiogenesis and microvessel density (MVD) in cases of microcystic, elongated and fragmented (MELF) pattern, with its prognostic role in the survival of endometrioid endometrial adenocarcinomas (EA) patients.

Methods

In this study, 100 cases of EA, 49 cases with MELF pattern and 51 without, were immunohistochemically stained for galectin-1, vascular endothelial growth factor (VEGF), and MVD. Morphometry and statistical (univariate and multivariate) analyses were performed to assess overall survival (OS) and disease-free survival.

Results

The expression of VEGF (p<.001) and galectin-1 (p<.001), as well as MVD area (p<.001) and number of vessels/mm² (p<.050), were significantly higher in the +MELF pattern group compared to the –MELF group. A low negative correlation between MELF-pattern and the number of days of survival (p<.001, r=–0.47) was also found. A low positive correlation of MELF-pattern with galectin-1 expression (p<.001, r=0.39), area of vessels/mm² (p<.001, r=0.36), outcome of EA (p<.001, r=0.42) and VEGF expression (p<.001, r=0.39) suggests potential pathological relevance of these factors in the prognosis of EA. A univariate survival analysis indicated a role for all parameters of survival. Multivariate Cox proportional hazard regression analysis revealed that only area of vessels/mm² (hazard ratio [HR], 1.018; 95% confidence interval [CI], 1.002 to 1.033), galectin-1 (HR, 1.049; 95% CI, 1.025 to 1.074) and VEGF (HR, 1.049; 95% CI, 1.022 to 1.077) play key roles in OS.

Conclusions

This study reports an increase in MVD, VEGF and galectin-1 expression in EA with MELF pattern and suggests that MELF pattern, along with the angiogenic profile, may be a prognostic factor in EA.