Elucidation of genomic origin of synchronous endometrial and ovarian cancer (SEO) by genomic and microsatellite analysis.

Most SEOs are likely to be a single tumor with metastasis instead of double primaries, and their origin could be endometrium. In addition, SEOs have a high frequency of MMR gene abnormalities. These findings not only can support the notion of uterine primary, but also can help to expect the benefit for patients with SEOs by immuno-oncology treatment.