P-081 - Serum tumor markers as predictors of overall response rate and clinical benefit in patients with advanced esophagogastric adenocarcinoma (EGA) treat...

Date 04 July 2015
Event WorldGI 2015
Session Posters
Topics Anti-Cancer Agents & Biologic Therapy
Oesophageal Cancer
Gastric Cancer
Translational Research
Presenter S.P. Cortez Castedo
Citation Annals of Oncology (2015) 26 (suppl_4): 1-100. 10.1093/annonc/mdv233
Authors S.P. Cortez Castedo1, M. Gion Cortes1, F. Longo Munoz1, R. Ferreiro Monteagudo1, V. Pachon Olmos1, M. Rodriguez Garrote1, M. Alsina2, J. Munoz del Toro1, A. Cortes Salgado1, P. Reguera Puertas1, A. Madariaga Urrutia1, M. Villamayor Delgado1, O. Martinez Saez1, J. Molina Cerrillo1, M.E. Olmedo Garcia1, E. Grande1, C. Guillen-Ponce3, A. Carrato4
  • 1Ramón y Cajal University Hospital, Madrid/ES
  • 2Vall d'Hebron Institute of Oncology, Barcelona/ES
  • 3IRYCIS, Madrid/ES
  • 4Hospital Ramón y Cajal, Madrid/ES

Abstract

Introduction

The clinical usefulness of tumor markers (TM) as predictors of response and clinical benefit in advanced EGA has been poorly defined. The aim of this study was to evaluate the prognostic significance of serum carcinoembryonic antigen (CEA), carbohydrate antigen (CA19-9) and cancer antigen 125 (CA125) levels in these patients.

Methods

From April 2011 through October 2014, baseline and nadir serum levels of CEA, CA19-9 and CA125 were detected in 67 patients diagnosed with metastatic EGA treated with first line treatment, and TM reduction ratio was calculated. Chemotherapy efficacy was evaluated according to RECIST 1.1, and the correlation between TM reduction ratio, overall response rate (ORR) and clinical benefit rate (CBR) were determined by Fisher test.

Results

Data of 67 patients (median age 67 years, range 42-88) were analyzed retrospectively. The most usual histological subtype was diffuse (31.3%); G3 histologic in 20.9%; Her2 overexpression in 22.4%. Fifty-one patients (76.1%) were diagnosed with advanced disease. The proximal stomach was the primary site in 79.1%. Elevated serum CEA, CA19-9 and CA125 levels were determined in 42 (62.7%), 37 (55.2%) and 37 (55.2%) respectively, and all TM were elevated in 23 (34.3%). Seventeen patients (25.4%) achieved a radiological partial response and stable disease in 14%. There was a significantly better ORR in patients who presented TM reduction ratio in CEA (p= 0.008) and CA 19-9 (p. 0.021) but not in CA 125 (p = 0.88). The clinical benefit rate was significantly better in patients with reduction ratio in CA 19-9 (p= 0.043) (Table 1). According to these results, we observed a better progression free survival (PFS) in patients with better ORR compared with them with no ORR [20 months (IC 95% 4.27-7.73) and six months (IC 95% 7.52-32.47) respectively (p = 0.003)].

Conclusion

TM reduction ratio in patients with advanced EGA is correlated with a better overall response rate in CEA and CA 19-9 and clinical benefit rate in the case of CA 19-9. Further data analyses would be helpful to develop a predictive model for tumor response.

Table: P-081