Therapeutic Challenges in the Management of Serous Endometrial Intraepithelial Carcinoma (SEIC).

Opinion statement: Serous endometrial intraepithelial carcinoma (SEIC) is an aggressive precursor and a similar biology to uterine serous carcinoma (USC). Patients diagnosed with SEIC should undergo surgical staging that includes total hysterectomy with bilateral salpingo-oophorectomy, lymph node sampling, and omentectomy. With trends in lymph node evaluation shifting towards sentinel lymph node sampling, we recommend bilateral sentinel lymph node sampling as a reasonable alternative to full pelvic and para-aortic lymphadenectomy. There is limited data to support the use of adjuvant chemotherapy, however, it is apparent that those with extrauterine disease have a higher likelihood of recurrence and decreased overall survival. Those with stage IVB SEIC have similar rates of survival to those with stage IVB USC and may be a population that could benefit from newer regimens for advanced stage endometrial cancer including immunotherapy and maintenance therapy. Unfortunately, strong data to support this will continue to be a challenge given the rare incidence of isolated SEIC without concurrent USC. The utility of adjuvant radiotherapy remains unclear and given its noninvasive nature and propensity for distant recurrence, may be of little utility. Regardless of the adjuvant therapies selected, routine surveillance like that of USC should be followed as recurrences are often noted greater than one year after initial surgery. Unlike other precursor lesions, SEIC behaves similarly to invasive carcinoma and ultimately should be treated as such for optimal disease control and outcomes.