Chemotherapy-induced transient CEA and CA19-9 surges in patients with metastatic or recurrent gastric cancer

Abstract

Background. Rising serum tumor markers after chemotherapy are generally considered to indicate tumor progression. However, we have observed a transient increase in carcinoembryonic antigen (CEA) or carbohydrate antigen 19-9 (CA19-9) levels despite clinical benefits from chemotherapy in patients with metastatic or recurrent gastric cancer (MRGC). Therefore, this study was performed to determine the incidence of CEA and CA19-9 surges and their implications on the clinical outcome in MRGC patients. Material and methods. Fifty-one and 40 patients who had evaluable data for CEA or CA19-9 surges, respectively, were included. Both CEA and CA 19-9 surges were defined as a > 20% increase in these tumor markers from the baseline that was followed by a > 20% drop in subsequent levels compared to the baseline. Results. Of 51 evaluable patients for CEA surges, nine patients (18%) had documented CEA surges. The median time to CEA peak and the duration of the CEA surge were 2.8 (1.7∼7.0) and 9.1 weeks (7.6∼21.0), respectively. Of 40 evaluable patients for CA19-9 surges, seven patients (18%) had CA19-9 surges. The median time to peak and the duration of the CA19-9 surge were 2.3 (1.9∼6.0) and 7.1 weeks (4.3∼16.1), respectively. All patients with CEA or CA19-9 surges had radiographic evidence of benefits from chemotherapy. Conclusion. CEA or CA19-9 surges can be observed in MRGC patients receiving chemotherapy. All patients with these surge phenomena had clinical benefits from chemotherapy. An initial rise in CEA or CA19-9 levels after initiation of chemotherapy should not be used as an indicator of progressive disease.