MUC16 and ovarian cancer: When ovarian cancer metastasizes to the upper gastrointestinal tract, the symptoms are often nonspecific, including abdominal pain, vomiting, anorexia, gastrointestinal bleeding, or anemia, which may delay diagnosis in many cases.14) Furthermore, serum CA125 level had been reported to be elevated in approximately 75% of patients with high-grade serous ovarian carcinoma.15) However, its diagnostic and monitoring value is considered less significant in OCCC.