Circulating arginine-vasopressin, calcitonin, carcinoembryonic antigen, neuron-specific enolase, and beta-2 microglobulin fluctuations during combined modality induction therapy for small-cell bronchogenic carcinoma. Association of postchemotherapy AVP surge with high tumor response rate and durable remission.

Abstract

While on combined modality induction therapy, 88 small-cell lung cancer (SCLC) patients were studied longitudinally for changes in circulating tumor-associated substances (TAS). Chemotherapy protocols were CAV (cyclophosphamide, doxorubicin, vincristine), PE (cisplatin, etoposide), sequential CAV greater than PE and alternate CAV/PE. Sixty patients were given prophylactic cranial irradiation (PCI) and 40 remitting patients were irradiated to the primary thoracic tumor. Of 73 evaluable patients, 43 had blood sampling adequate for analysis of treatment-related TAS fluctuations. Fourteen patients demonstrated 16 events of transient arginine-vasopressin surge following chemotherapy. In decreasing order of frequency, the surge occurred after the first (9), second (6) and third (1 event) course of chemotherapy. Three patients had a concomitant increase of one of the following markers: carcinoembryonic antigen (CEA), calcitonin and neuron-specific enolase. Another patient showed an exclusive CEA surge. This group of patients (10 with limited, 4 with extensive disease) had a 93% objective response rate (57% complete, 36% partial) with a median duration of 9 months and a survival of 15 months. Five other patients, 2 with limited and 3 with extensive disease, showed a TAS surge after PCI. Their response was complete in 1 (8 months' duration) and partial in 3 cases (2, 4 and 4 months' duration, respectively) with a median survival lasting only 8 months. This study suggests that a chemotherapy-related TAS surge may be an early indicator of a favorable tumor response in SCLC.