Levels of beta-human chorionic gonadotropin in cerebrospinal fluid of patients with malignant germ cell tumor can be used to detect early recurrence and monitor the response to treatment

Background: Tumor marker-producing germ cell tumors of the central nervous system are malignant and require radiation and/or chemotherapy. Although se rum beta-human chorionic gonadotropin (hCG) has been used to monitor the co urse of treatment, the levels of beta-hCG in the cerebrospinal fluid (CSF) have not been measured routinely in the clinic. To determine whether they c an be used to evaluate parameters of tumor status, such as progression or r esponse to therapy, levels of beta-hCG in the serum and CSF of patients wit h germ cell tumors were studied. Methods: Fifty-four paired samples of CSF and serum were taken from seven p atients with germ cell tumor and their beta-hCG levels were measured. beta- hCG was negative in both serum and CSF in 11 instances and the levels in th e other 43 paired samples were analyzed for any correlation or relationship to therapy. They were also compared with the clinical courses. Results: The mean CSF beta-hCG level was 11.5 mlU/ml, which was significant ly higher than the level in serum (3.5, p = 0.002). In all the paired sampl es except for one time point, the level in CSF was higher than that in seru m. Out of 43 instances where the beta-hCG level in CSF was elevated, the le vel in serum was elevated in only 16 (37.2%). Among cases of recurrent mali gnant germ cell tumor, there were nine instances of recurrence or progressi on despite therapy. In all five instances where beta-hCG CSF levels were me asured, the levels were elevated prior to any increase or detectability of the serum values. Conclusion: It seems likely that the level of beta-hCG in CSF is a good mar ker for monitoring tumor recurrence or evaluation of treatment results.