Original contributionClinicopathological analysis of mixed endometrial carcinomas: clinical relevance of different neoplastic components

- According to the data from literature, MECs comprise about 10% of all endometrial cancers, although the definitive and univocal occurrence estimation is not precisely defined due to their rarity.
- As reported by the literature, specific quantification of the distinct components of MECs represents a challenging and critical point for both prognosis and management.
- The evaluation of some prognostic parameters, despite the biases encountered, assessed that MECs, characterized by a type II component larger than 5%, represent a more aggressive entity.
- According to some of our results, MECs are likely to be followed by personalized and tailored managements with the exact definition of the different percentage and histotypes.
- The presence of these different components may suggest that different pathogenic and metastatic mechanisms may be involved in their cancer genetic process.

SummaryMixed endometrial carcinomas (MECs) refer to tumors characterized by 2 or more distinct histotypes mostly that comprised endometrioid (EC) and serous/clear cell carcinomas (SC/CC). The specific quantification of these distinct components represents a challenging and critical point for both prognosis and management. Herein, we analyze a large series of MEC and compare them with EC and SC/CC. We evaluated a series of 69 MECs between January 2002 and December 2015. We compared the MEC series with 186 ECs (including 117 endometrioid G3), 31 SCs, and 38 CCs. The prognostic implication of the percentage of each component was analyzed. Among the 69 MECs, those patients older than 45 years represent the significant population, with 52.2% of them with stage III-IV disease. A similar result was found among pure SC. The comparative analysis of some prognostic parameters (multifocality, vascular invasion, and lymph node metastasis) underlined that MECs with a type II component larger than 5% represent a more aggressive entity. However, relapse, disease-free survival, mortality, and overall survival are statistically significant (P < .05) in EC-SC (SC <5% or >5%) and in EC-CC (CC <5% or >5%), whereas they are not significant (P > .05) in SC-CC (SC/CC <% or >5%). MECs, including also cases with less than 5% of SC/CC, show features as aggressive as those of pure SC/CC. In this perspective, MEC should be followed by personalized and tailored managements. The presence of different components suggests different pathogenic and metastatic processes when compared with pure carcinomas.