Evaluation of the outcome of adjuvant treatment for gastric cancer in Brazil and Peru: A retrospective study in two cancer centers in Latin America.

Abstract

160 Background: Gastric cancer (GC) is one of the most frequent malignancies in developing countries. In Peru, it is the fourth most incident cancer, and the sixth one in Brazil. Mortality is still high. The chance of relapse of patients with non-metastatic disease undergoing surgery is more than 50%. It is suspected that Latin American patients present worse evolution compared to those treated in Asia or in developed countries, therefore it is fundamental to study factors related to the prognosis and evolution of patients with GC in our continent. We aimed to evaluate the outcome of adjuvant treatment for GC in patients from two countries with different racial miscegenation and eating habits, and correlate this with clinicopathological features. Methods: We retrospectively analyzed 187 patients with GC who underwent curative surgery and received CRT at AC Camargo Cancer Center (ACCCC) in Brazil and Instituto Nacional de Enfermedades Neoplasicas (INEN) in Peru. CRT was defined as MacDonald protocol. Primary endpoint was overall survival (OS). Cox regression model was performed in order to calculate hazard ratio (HR) and 95% confidence intervals (95%CI). Results: Median follow up time was 51 and 20 months in Brazil and Peru, respectively. Median age of our cohort was 54 years-old. Male sex was predominant in both countries (Brazil: 54.7%; Peru: 56.9%). Diffuse subtype also was predominant (Brazil: 58.3%; Peru: 55.1%). Median OS was 103.9 and 45.2 months in Brazil and Peru respectively (p < 0.001). In the multiple analysis, we found that pathological stage (I/II vs. III; HR = 4.1, 95%CI 1.4-11.7; p = 0.009) was independent prognostic factor adjusted by country of treatment, histological subtype, localization, age and gender. Conclusions: Survival differences exist between Brazil and Peru. We observed that patients from Peru had more advanced pathological stage after surgery. This difference suggests a possible prognostic factor in OS. Ethnic/genetic factors, eating habits and other clinicopathological or molecular factors may also explain different prognosis. Future studies are warranted to determine these prognostic factors in Latin American gastric cancer patients.