Serum Sialyl-Tn (STN) as a Tumor Marker in Patients with Endometrial Cancer.

There are no potential tumor markers validated for prognosis of endometrial cancer. However, sialyl Tn (STN) is a carbohydrate antigen that is associated with the production of mucin, which reportedly plays important roles in carcinogenesis. Although STN expression in endometrial cancer has been investigated, its prognostic value remains controversial and no studies have investigated serum STN levels in large case series. In this study, we investigated diagnostic and prognostic applications of serum STN for endometrial cancer. Between January 2006 and December 2012, serum STN levels were examined prospectively in patients with endometrial cancer. A total of 146 patients (stage I, 98; stage II, 15; stage III, 17; stage IV, 16) were treated for endometrial cancer. The median age was 60 years (28-83). Subsequently 29 patients (19.9%) relapsed at the time of the last follow-up and the median follow-up time was 44 months (1-83). Elevated serum STN levels were identified in 36 patients (24.7%) and were associated with histological grade (p = 0.02) and lymph node metastasis (p = 0.006). Elevated serum STN levels were not related to histological types, clinical stages, myometrial invasions, distant metastases, age, menopausal status, body mass index, or relapse. Among the 36 patients with elevated serum STN levels, 33 (91.7%) achieved remission and serum STN levels returned to the normal range. Seven patients (21.2%) with elevated serum STN levels at baseline relapsed and their serum STN levels were again elevated. Serum STN levels are a potential prognostic indicator for endometrial cancer.