Serous papillary cystadenocarcinomas of the ovaries express
**Core Concept**
Serous papillary cystadenocarcinomas of the ovaries are a type of epithelial cancer that originates from the surface epithelium of the ovary. The tumor marker CA-125 is commonly associated with this type of ovarian cancer, and its expression is used as a diagnostic and prognostic tool.
**Why the Correct Answer is Right**
CA-125 is a mucin-like glycoprotein that is overexpressed on the surface of serous papillary cystadenocarcinomas of the ovaries. The overexpression of CA-125 is thought to be due to the abnormal expression of the MUC16 gene, which encodes for the CA-125 protein. Elevated levels of CA-125 in the serum of patients with ovarian cancer are associated with a poorer prognosis and are used as a marker for disease recurrence.
**Why Each Wrong Option is Incorrect**
**Option B:** CA-19-9 is a tumor marker that is commonly associated with pancreatic cancer, not ovarian cancer.
**Option C:** CEA (carcinoembryonic antigen) is a tumor marker that is associated with a variety of cancers, including colorectal, breast, and lung cancer, but it is not specifically associated with serous papillary cystadenocarcinomas of the ovaries.
**Option D:** AFP (alpha-fetoprotein) is a tumor marker that is associated with hepatocellular carcinoma and certain germ cell tumors, but it is not associated with serous papillary cystadenocarcinomas of the ovaries.
**Clinical Pearl / High-Yield Fact**
It's essential to note that while CA-125 is a useful marker for serous papillary cystadenocarcinomas of the ovaries, it is not specific to this type of cancer and can be elevated in other conditions, such as endometriosis, pelvic inflammatory disease, and benign ovarian cysts.
**✓ Correct Answer: A. CA-125**