Ca125 and neuron-specific enolase (NSE) as tumour markers for intra-abdominal desmoplastic small round-cell tumours

Seven consecutive patients with intra-abdominal desmoplastic small round-cell tumours were screened at presentation for carcinoembryonic antigen (CEA), Ca19-9, Ca15-3, Ca125, alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG) and neuron-specific enolase (NSE). Initially elevated tumour markers were used to monitor therapy and follow-up. Tumour marker assays were all in the normal range, with the exception of Ca125 and NSE. The Ca125 level was initially high in six of the seven patients (86%) with a median value of 200 U ml^-1 and a range of 22-735 U ml^-1. The NSE value was elevated before therapy in three of the five patients (60%) for whom assay results were available, with a median of 19 ng ml^-1 and a range of 6.8-37.5 ng ml^-1. Ca125 normalized in five out of six cases and NSE always normalized during chemotherapy, but neither of these two tumour markers correlated specifically with response, as only one patient experienced a partial response, five tumour stabilization and the remaining patient tumour progression. At progression, Ca125 was again elevated in two out of four cases several weeks before clinical relapse and NSE in only one out of three cases. Ca125 and NSE are frequently raised in the serum of patients with intra-abdominal desmoplastic small round-cell tumours before therapy, but are not reliable monitors of the course of the disease. However, normalization is frequently associated with an improvement of symptoms or a moderate clinical response.