Clinical significance and pitfalls of human chorionic gonadotropin-related tumor markers for intracranial germinomas.

PURPOSE

Measuring serum and cerebrospinal fluid human chorionic gonadotropin (hCG) is essential for the diagnosis of intracranial germ cell tumors. There are three types of hCG-related markers in clinical use: hCGβ, intact hCG, and total hCG. The best marker for the diagnosis of intracranial germ cell tumors, especially germinoma, is currently unknown. This study aimed to evaluate the usefulness of these hCG-related markers.

METHODS

We investigated 19 serum samples obtained from 6 patients with histologically diagnosed germinoma treated in our institute. Serum hCGβ, intact hCG, and total hCG values were measured before, during, and after treatment. Samples with hCG values above the lower limits were considered positive.

RESULTS

The positivity rates of serum hCGβ, intact hCG, and total hCG were 6% (1/17), 47% (7/15), and 42% (8/19), respectively, with the latter two having significantly higher positivity rates than hCGβ (p = 0.041). Both intact and total hCGs showed similar values. The median values of hCGβ, intact hCG, and total hCG before treatment were 0.1 ng/mL, 4.6 mIU/mL, and 4.5 mIU/mL, respectively.

CONCLUSION

Serum intact and total hCGs have higher detection rates than hCGβ in patients with germinoma using available commercial measurement tools.