CA 125 is particularly used to monitor which cancer?

CA 125 is a tumor marker that is most commonly associated with ovarian cancer. It is a glycoprotein that can be elevated in the blood of individuals with ovarian tumors, particularly in those with epithelial ovarian carcinoma, which is one of the most common and aggressive forms of this disease.

The utility of CA 125 lies primarily in its use for monitoring disease progression and response to treatment in patients already diagnosed with ovarian cancer rather than as a standalone diagnostic tool. Elevated levels can indicate the presence of cancer, but they can also be raised due to benign conditions, so they are not specific enough for initial screening.

In the context of other cancers listed, CA 125 levels are not typically elevated in significant amounts or used as a monitoring tool. For example, while breast cancer may utilize other markers, such as estrogen and progesterone receptors or HER2/neu levels, CA 125 does not play a role. Similarly, colorectal cancer may involve markers like carcinoembryonic antigen (CEA), and neuroblastoma has its specific markers, such as vanillylmandelic acid (VMA) and homovanillic acid (HVA). Thus, the specific association of CA 125 with ovarian cancer makes it the correct choice for monitoring