Undifferentiated embryonal sarcoma of the liver in adults: Retrospective analysis of a case series and systematic review.

Adult undifferentiated embryonal sarcoma of the liver (UESL) is an aggressive malignant tumor. As UESL is rare, the literature predominantly includes case reports, with a limited number of small case series. The aim of the present study was to investigate the presentation, treatment modalities and outcomes of this rare tumor. The present study includes a case series of adult UESL and a systematic review. A single-institution case series of adult UESL were retrospectively analyzed, and a systematic review of adult UESL was performed by searching MEDLINE, Web of Science, EMBASE, the Google Scholar database and the Cochrane Library. For all identified adult UESL cases, the demographic variables, treatments and survival were analyzed. Three female adult patients with UESL (median age, 21 years) were successfully treated by complete tumor resection, with or without adjuvant chemotherapy, at Beijing Tsinghua Changgung Hospital between 2015 and 2018. Of these patients, two are currently alive (follow-up, 9 and 41 months), and one died after pulmonary recurrence 17 months post-diagnosis. The present systematic review identified 108 cases of adult UESL. Among all 111 analyzed cases, the median overall and disease-free survival rates were as follows: 1-year, 72 and 67%; 3-year, 56 and 40%; and 5-year, 47 and 35%, respectively. Treatment strategies combining complete tumor resection and chemotherapy promoted improved overall and disease free survival time compared with radical tumor resection alone. The present analysis included one of the largest case series of UESL in adults, and is the first such study to present survival rates. The results of the present study confirmed that survival was improved by treatment strategies combining complete tumor resection and chemotherapy.