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

Blood Vessel Invasion Is an Independent Prognostic Factor in Endometrial Endometrioid Carcinoma Compared to Lymph Vessel Invasion and Myometrial Invasion Pattern

We studied 115 cases of EEC diagnosed on hysterectomy specimens. Double immunohistochemical staining (D2-40/CD31) was performed in all 115 cases to show LVI and BVI on the same slide. MELF pattern invasion was present in 24/115 (21%) cases. MELF-positive tumors had a higher frequency of LVI than MELF-negative tumors (58% and 23%, respectively); the frequency of BVI was twice as high in MELF-positive tumors in comparison to MELF-negative tumors (25% and 12%, respectively). These differences were significant (p ˂ 0.0001). All tumors with positive BVI also had a concomitant LVI. The presence of MELF invasion had no impact on overall survival, confirming previous studies. 5-year survival rates were almost equal in cases with negative LVSI and cases with positive isolated LVI (98% vs. 97%). However, in cases where BVI was also present, the 5-year survival rate was significantly lower, 63% (p ˂ 0.0001). Furthermore, BVI proved to be an independent prognostic factor for overall survival, disease-free survival, and recurrence in the multivariate analysis. In conclusion, MELF pattern invasion is a good predictor of lymphatic and blood vessel invasion but has no prognostic value. Our results suggest that BVI in EEC has greater clinical value than isolated LVI or myometrial invasion patterns, and the therapeutic approach should be guided by BVI presence. Therefore, we hope this study will promote the routine evaluation of BVI in the context of EEC diagnostic procedures.

Molecular Classification of Endometrial Endometrioid Carcinoma With Microcystic Elongated and Fragmented Pattern

The studies on the molecular classification of endometrioid carcinoma (EC) with microcystic, elongated, and fragmented (MELF) pattern invasion are limited. In this study, 77 cases of ECs with MELF patterns in Chinese women were collected. The molecular classification of the fifth edition of the World Health Organization was used to classify the molecular subtypes using immunohistochemistry staining (mismatch repair [MMR]-immunohistochemistry: MSH2, MSH6, MLH1, and PMS2; p53) and Sanger sequencing targeted POLE . The results showed that the prevalence of the 4 molecular subtypes in EC with MELF pattern was 6.5% (5/77) for POLE mutation, 20.8% (16/77) for MMR deficient, 11.7% (9/77) for p53-mutant, and 61.0% (47/77) for no specific molecular profile. The clinicopathological characteristics of each subtype were compared. The p53-mutant and no specific molecular profile subgroups were associated with higher International Federation of Gynecology and Obstetrics stage and International Federation of Gynecology and Obstetrics grade, deeper myometrial invasion, lymphovascular space invasion, lymph node metastasis, and absence of tumor-infiltrating lymphocytes, whereas the POLE mutation and MMR deficient subgroups were associated with lower aggressive features and prominent tumor-infiltrating lymphocytes. Progression-free survival showed that the p53-mutant and no specific molecular profile subgroups had a poorer prognosis than the POLE mutation and MMR deficient subgroups. However, lymph node metastasis was an independent factor associated with a higher risk of disease recurrence in multivariate analysis. In conclusion, ECs with MELF patterns can be divided into 4 molecular subtypes with discrepancies in aggressive clinicopathological characteristics and tumor-infiltrating lymphocytes. Molecular classification has clinical significance in a morpho-molecular approach for ECs with MELF patterns.

Endocervical Adenocarcinoma Showing Microcystic, Elongated, and Fragmented (MELF) Pattern of Stromal Invasion: A Single-Institutional Analysis of 10 Cases with Comprehensive Clinicopathological Analyses and Ki-67 Immunostaining

Microcystic, elongated, and fragmented (MELF) pattern of invasion has seldom been documented in endocervical adenocarcinoma (EAC). The aim of this study was to analyze the clinicopathological characteristics of EAC showing MELF pattern. We collected the clinicopathological information of 10 cases of EAC with the MELF pattern and conducted polymer-based immunostaining for Ki-67 (dilution 1:200, clone MIB-1) on these cases. Ki-67 expression was assessed using the average estimation within the hotspot method. All tumors were human papillomavirus-associated EAC with Silva pattern C. All except one tumor exceeded 3 cm in size. Five tumors involved the entire thickness of the cervical stroma, and four tumors extended into the parametrium. Lymphovascular space invasion was identified in six cases. Two patients developed metastatic recurrences in the para-aortic lymph nodes and lungs, respectively. The MELF area showed significantly lower Ki-67 labelling index than that of a conventional tumor area. We confirmed our previous observation that the MELF area displayed lower proliferative activity than the conventional tumor area of EAC. We also demonstrated that patients with EAC showing MELF pattern had several adverse clinicopathological characteristics reflecting aggressive behavior. On the other hand, since the frequencies of post-operative recurrence and disease-related mortality that occurred during the follow-up period were relatively low, further investigations are warranted to clarify the prognostic value of MELF pattern in EAC patients.

Infection status and survival impact of high-risk human papillomavirus in cervical adenocarcinomas: A systematic review and meta-analysis

OBJECTIVE

Cervical adenocarcinoma (CAC) comprises a heterogeneous group of tumors that are not universally associated with HPV infection. As has been shown in other organs, it is becoming increasingly apparent that HPV status significantly affects the prognosis of adenocarcinoma. We conducted a systematic review and meta-analysis to investigate the infection status of high-risk Human papillomavirus (hrHPV) in CAC and evaluate its impact on the survival of patients.

METHODS

PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), International Clinical Trials Registry Platform (ICTRP), and Clinical Trials.gov were searched from inception to May 1st, 2022. Data on HPV infection status and survival outcomes were evaluated using STATA 16.0.

RESULTS

Seventy-one studies with 11,278 participants were included in HPV infection analysis and eight studies with 1099 participants were included in prognosis analysis. The HPV infection rate (including high-risk and low-risk) and hrHPV infection rate in CAC were 75% (95% CI 0.70-0.80, 6978 participants) and 75% (95% CI 0.70-0.81, 4906 participants), respectively. HPV-16 and -18 were the most common HPVs in CAC, with pooled infection rates of 37% (95% CI 0.33-0.41, 7848 participants) and 34% (95% CI 0.30-0.38, 7730 participants), respectively. hrHPV infection was associated with better overall survival (HR 0.23, 95% CI 0.11-0.47, 1013 participants), better disease-free survival (HR 0.18, 95% CI 0.07-0.43, 292 participants), better progression-free survival (HR 0.20, 95% CI 0.08-0.47, 271 participants) and less recurrence (RR 0.30, 95% CI 0.07-0.43, 181 participants).

CONCLUSION

HPV infection rates were high in CAC. HPV-16 and -18 had the highest infection rates in CAC. However, hrHPV infection was associated with better survival and less recurrence. Future studies should clarify the relationship between hrHPV infection and other prognostic factors and make reasonable treatment strategies for CAC with different HPV status.

PROTOCOL REGISTRATION

CRD42022319390.

Microcystic elongated and fragmented (MELF) pattern of invasion: Molecular features and prognostic significance in the PORTEC-1 and -2 trials

OBJECTIVE

Microcystic, elongated fragmented (MELF) pattern of myometrial invasion is a distinct histologic feature occasionally seen in low-grade endometrial carcinomas (EC). The prognostic relevance of MELF invasion was uncertain due to conflicting data, and it had not yet appropriately been studied in the context of the molecular EC classification. We aimed to determine the relation of MELF invasion with clinicopathological and molecular characteristics, and define its prognostic relevance in early-stage low/intermediate risk EC.

METHODS

Single whole tumor slides of 979 (85.8%) out of 1141 (high)intermediate-risk EC of women who participated in the PORTEC-1/-2 trials were available for review. Clinicopathological and molecular features were compared between MELF invasion positive and negative cases. Time-to-event analyses were done by Kaplan-Meier method, log-rank tests and Cox' proportional hazards models.

RESULTS

MELF invasion was found in 128 (13.1%) cases, and associated with grade 1-2 histology, deep myometrial invasion and substantial lymph-vascular space invasion (LVSI). 85.6% of MELF invasion positive tumors were no-specific-molecular-profile (NSMP) EC. NSMP EC with MELF invasion were CTNNB1 wild type in 92.2% and KRAS mutated in 24.4% of cases. Risk of recurrence was lower for MELF invasion positive as compared to MELF invasion negative cases (4.9% vs. 12.7%, p = 0.026). However, MELF invasion had no independent impact on risk of recurrence (HR 0.65, p = 0.30) after correction for clinicopathological and molecular factors.

CONCLUSIONS

MELF invasion has no independent impact on risk of recurrence in early-stage EC, and is frequently observed in low-grade NSMP tumors. Routine assessment of MELF invasion has no clinical implications and is not recommended.

Clinicopathological and Molecular Differences Between Gastric-type Mucinous Carcinoma and Usual-type Endocervical Adenocarcinoma of the Uterine Cervix

BACKGROUND/AIM

We investigated differences in the clinicopathological and molecular characteristics between gastric-type mucinous carcinoma (GMC) and usual-type endocervical adenocarcinoma (UEA).

PATIENTS AND METHODS

We collected the clinicopathological information and performed targeted genomic sequencing analysis.

RESULTS

GMCs exhibited significantly deeper invasion depth, larger horizontal spread, more advanced stage, more frequent distant metastasis, and more frequent parametrial and vaginal extension. Disease-free survival time of GMC patients was significantly shorter than that of UEA patients. GMCs displayed mutant p53 immunostaining pattern, whereas UEAs exhibited p16 block positivity. GMCs harbored mutations in KRAS, TP53, NF1, CDKN2A, STK11, and ARID1A. One GMC exhibited MDM2 amplification. In contrast, UEAs harbored mutations in HRAS, PIK3CA, and BRCA2. Two UEAs were found to have novel TP53 mutations.

CONCLUSION

GMC is associated with more aggressive behavior than UEA. Distinctive p53 and p16 immunostaining patterns enable differential diagnosis. GMC and UEA exhibit genetic heterogeneity with potentially actionable molecular alterations.

Survey Results on Pathologic Aspects of Endocervical Adenocarcinoma by the International Society of Gynecological Pathologists

The International Society of Gynecological Pathologists (ISGyP) undertook a project to provide evidence-based recommendations for pathologic reporting of all aspects of endocervical adenocarcinoma. The first step in the process was the design of an extensive survey to collect baseline information on existing practices regarding grossing, processing, diagnosing, and reporting of endocervical adenocarcinoma among the members of the society. The web-based survey of 98 questions was emailed to all members of ISGyP and there were 175 respondents (38.5% of ISGyP members). The responses, as expected, revealed areas of uniformity but also areas of substantial variation. The results of the survey are presented herein and assisted in developing the recommendations presented in the other reviews in this issue.

Usual-Type Endocervical Adenocarcinoma with a Microcystic, Elongated, and Fragmented Pattern of Stromal Invasion: A Case Report with Emphasis on Ki-67 Immunostaining and Targeted Sequencing Results

The microcystic, elongated, and fragmented (MELF) pattern is a unique myometrial invasion pattern occasionally found at the invasive front of endometrial endometrioid carcinoma (EEC). Herein, we report an uncommon case of usual-type endocervical adenocarcinoma (UEA) with a MELF pattern. We comprehensively analyzed its clinicopathological and molecular features, which has not been previously documented. A 67-year-old woman presented with a cervical mass and underwent radical hysterectomy. Histologically, the MELF pattern of UEA was almost identical to that of EEC. Tumor glands exhibited a microcystic appearance or elongated structures with compression forming a slit-like lumen. The tumor glands were irregularly fragmented into small clusters or single cells. Cells lining the tumor glands possessed conspicuous eosinophilic cytoplasm with squamoid or flattened endothelium-like appearance. These glands or cells were accompanied by a prominent fibromyxoid stromal reaction. Lymphovascular invasion was occasionally observed. Immunostaining revealed diffuse and strong cytokeratin 7 expression and block p16 positivity in both conventional and MELF components. However, the MELF component displayed a very low Ki-67 proliferation index compared to that of the conventional component, which showed markedly increased Ki-67 expression. Targeted sequencing analysis revealed that the MELF component harbored pathogenic mutations in ARID1A, KRAS, and PTEN, identical to those detected in the conventional component. In summary, the morphological features of the MELF pattern in UEA were similar to those in EEC. We found significant differences in Ki-67 expression status between conventional and MELF components, but the mutational profiles were identical. Our findings should be confirmed in larger cohorts of patients with UEA showing a MELF pattern.