Germ-cell tumors

Patients presenting with a lump in the testes or a malignancy of unknown origin should have plasma (AFP) and (hCG) measured. If raised due to secretion by the tumor, these measurements can also be used to monitor treatment. However, only about 75% of non-seminomatous germ-cell tumors and a minority of patients with seminoma or dysgerminoma secrete these markers.

Choriocarcinoma

About 50% of cases of Choriocarcinoma and hCG is used to screen these women: hCG is also used to asses prognosis and response to treatment.

Ovarian cancer

Measurements of the cancer antigen CA-125 are used to monitor treatment and during follow up in patients with non-germ cell ovarian tumors. CA-125 measurements may also aid diagnosis, but measurements do not appear to be of value in prognosis or screening.

Prostatic cancer

Prostatic acid phosphatase measurements were once widely used as a marker for prostatic cancer, but it is now recognized that the glycoprotein prostate specific antigen (PSA) is a superior marker. Serum PSA raises with age, and levels are also increased in benign prostatic hypertrophy, lower urinary tract infections and after trauma to the prostate. Screening of the general population is not recommended, partly because of the above mentioned, but more importantly because of uncertainties about the efficiency of various treatment strategies for early prostatic cancer. Most PSA circulates in plasma bound to alpha antichymotrypsin, but a small fraction circulates unbound to any protein (free PSA). Patients with prostatic cancer appeal to have a higher ratio between alpha antichymotrypsin PSA complex and free PSA than patients with benign hypertrophy this may be of diagnosis value. PSA is of value in monitoring the response to therapy.