Clinicopathological Criteria and Prognostic Factors in Gastric Adenocarcinoma in Kuwait

Abstract

Background: Gastric cancer is the 5th most common cancer in the world and 2nd leading cause of cancer deaths. It has marked geographic incidence variation. Most common in Japan, China, other East Asian countries, Eastern Europe and South America. There is sharp decrease in incidence in western countries over the past 60 years but incidence of GE junction and proximal gastric tumors is increasing. In state of Kuwait in 2012 ASR was 2.6/100,000 population (similar to other Gulf countries; apart from Oman). There are many known risk factors including eating smoked and salted food and H. pylori infection. Aim: The aim of this study is to analyze gastric cancer diagnosed cases from 2009 to 2015 in Kuwait and to analyze clinicopathological criteria and prognostic factors. Methods: A total of 145 adult patients with newly diagnosed gastric cancers were treated and followed-up at Kuwait Cancer Control Center (KCCC) between 2009-2015. Patients' data were examined retrospectively. In all cases: age, performance status, sex, ethnicity, smoking and dietary habit, tumor site, pathology, staging and type of treatment were identified. Survival analysis was done using Kaplan-Meier, and comparison was done using long-rank test. Results: The median age at diagnosis was 54 (29-94). Men represented 63.5%. 75.2% had adenocarcinoma, 14.5% gastric lymphoma, 6.2% GIST, 3.4% carcinoid and 1 case squamous cell carcinoma. For gastric adenocarcinoma, 22 were metastatic (20.2%). In spite of composing almost 25% of country population and expected high incidence in their home countries, only 19.5% of patients were Asian with known habit of spicy food intake. 31% of patients were smokers. Performance at diagnosis was ECOG 0-1 in majority. Median follow-up was 45 months (1-89) and median overall survival was 34 months (0.5-89). Almost half of tumors were poorly differentiated with signet-ring feature in 36.8%. 12.6% presented with clinically advanced tumor but after surgery the number upstaged to be 25.9% (Stage III). Tumor epicenter localization was almost equivalent with 43 (49.4%) localized proximally and 44 (50.6%) distally. Surgery was the main treatment in majority (85.1%) while radiation was used in 58.6% and chemotherapy in 74.4% (adjuvant, neoadjuvant or concomitant). 22 patients failed; 7 locoregionally, 15 had distant metastasis while 2 patients failed both locally and distantly. Close surgical margins, and proximal localization were poor prognostic factors. Age and ethnicity had no impact on outcomes in our cohort. Conclusion: Gastric adenocarcinoma in Kuwait has similar profile to that documented worldwide and regionally (apart from Oman). Proximal tumors represent a challenge and has poorer prognosis that may need more intensification of treatment. Current (neo)adjuvant treatment seem to be effective in our population. Molecular profiling and studies are needed for further understanding of this potentially curable disease.