Simona Duranti

A Case Report to Reflect on the Origins of MMRd Mesonephric-like Ovarian Adenocarcinoma: Can It Be Defined as a Mϋllerian Neoplasm?

Mesonephric-like adenocarcinoma (MLA) of ovaries is a new and rare neoplastic entity, recently classified by the World Health Organization. Its morphological and immunohistochemical profile is similar to primitive cervical mesonephric adenocarcinoma, but its origin has not been determined yet. Some authors believe that this neoplasm originates from Wolffian remnants in the ovarian hilum, while others suggest an origin from the Mϋllerian epithelium, followed by a mesonephric trans-differentiation. Starting from a recently diagnosed mismatch repair-deficient ovarian MLA, we try to further develop this line of research. A detailed molecular analysis of the studied tumor helps clarify our ideas. In fact, the typical KRAS mutation was not present. We found mutations in numerous other genes, which are rarely described in the literature or are already described in the endometrioid histotype. We reached some interesting conclusions, which, if supported by future studies, will clarify the true nature of these tumors, allowing for better stratification and a better therapeutic framework.

Are all mismatch repair deficient endometrial cancers created equal? A large, retrospective, tertiary center experience

One third of endometrial carcinomas (ECs) presents with mismatch repair deficiency (MMRd). Of these, 70 % are caused by somatic hypermethylation of MLH1 promoter; the remaining cases are determined by Lynch syndrome or double somatic inactivation of MMR genes. Although associated with good-intermediate prognosis, heterogeneity in treatment response and survival has been reported among MMRd ECs. We aim to investigate differences in pathologic aggressiveness and event-free survival (EFS) among three MMRd EC subtypes, classified by immunohistochemistry (IHC) and MLH1 methylation analysis. Subjects undergone surgical staging for EC were retrospectively included. IHC analysis was performed in all patients to assess MMR and p53 status. Methylation analysis was performed in MMRd patients with IHC-negative MLH1. The MMRd population was classified into: 1)MLH1-hypermethylated (MLH1-HyMet); 2)MLH1-unmethylated (MLH1-UnMet); 3)IHC-negative MSH2 and/or MSH6 or PMS2 alone (non-MLH1). Of 1171 patients undergoing surgical staging and IHC assessment, 362 (30.9 %) were classified as MMRd and included in the analysis. Among these, 59.7 % (n = 216) were MLH1-HyMet, 11 % (n = 40) MLH1-UnMet, and 29.3 % (n = 106) non-MLH1. Compared to MLH1-UnMet and non-MLH1, MLH1-HyMet was associated with older age, higher BMI, larger tumor size, deeper myometrial invasion, substantial lymphovascular space invasion, lower frequency of early-stage and low-risk disease. EFS was similar when comparing the MMRd subtypes, even after adjusting for stage and tumor histology. However, a trend of MLH1-HyMet toward poorer prognosis can be observed, particularly in the advanced/metastatic setting. MLH1-hypermethylated MMRd ECs display more aggressive clinicopathologic features compared to the other MMRd subgroups. However, although a suggestive trend toward poorer EFS was observed in the hypermethylated subset, particularly in the advanced setting, no significant differences in prognosis were detected among the MMRd subtypes.

POLE mutations in endometrial carcinoma: Clinical and genomic landscape from a large prospective single‐center cohort

AbstractBackgroundTo date, 11 DNA polymerase epsilon (POLE) pathogenic variants have been declared “hotspot” mutations. Patients with endometrial cancer (EC) characterized by POLE hotspot mutations (POLEmut) have exceptional survival outcomes. Whereas international guidelines encourage deescalation of adjuvant treatment in early‐stage POLEmut EC, data regarding safety in POLEmut patients with unfavorable characteristics are still under investigation. On the other hand, the spread of comprehensive genome profiling programs has underscored the need to interpret POLE variants not considered to be hotspots.MethodsThis study provides a comprehensive analysis of 596 sequenced patients with EC. The genomic landscape of POLEmut EC was compared with cases harboring nonhotspot POLE mutations within the exonuclease domain. Additionally, the genomic characteristics of multiple classifiers, as well as those exhibiting unfavorable histopathological and clinical features, were examined.ResultsNo significant genomic differences were observed among patients with POLEmut EC when comparing multiple classifiers to not‐multiple classifiers or those with unfavorable clinical features. However, the tumor mutational burden differed in both comparisons, whereas the percentage of C>G mutations only differed in the comparison based on clinical features. Specific POLE mutations, even if not considered to be hotspots, have genomic features comparable to POLEmut.ConclusionsThe present findings confirm the absence of significant genomic differences among POLEmut patients regardless of multiple‐classifier status or association with high‐risk clinical features. Prognostic data will be essential to elucidate the clinical significance of POLE mutations not classified as hotspots that exhibit genomic characteristics similar to those in POLEmut patients.

Oregovomab: an investigational agent for the treatment of advanced ovarian cancer