I. Nassour1, A. A. Mokdad1, M. Khan1, J. C. Mansour1, A. C. Yopp1, R. M. Minter1, P. M. Polanco1, M. M. Augustine1, M. A. Choti1, S. C. Wang1, M. R. Porembka1 1University Of Texas Southwestern Medical Center,Division Of Surgical Oncology,Dallas, TX, USA
Introduction: About 10% of patients with gastric cancer present at young age. Previous studies have reported conflicting prognosis for young gastric patients. The aim of this study is to describe the clinicopathological characteristics, prognostic features, and outcomes from gastric cancer among young patients (18-49 years) compared to middle aged (50-69 years) and elderly patients (70 years).
Methods: We identified patients with gastric cancer in the National Cancer Data Base between 2006 to 2013. We analyzed patient-, tumor-, and treatment-related factors among all three groups using standard statistical methods. Disease stage was divided into early stage (IA), locally advanced (IB-IIIC), and metastatic (IV). Relative survival was calculated as the ratio of observed survival to expected survival for the United States general population matched for age and sex. The log-rank test was used to compare survival rates among the groups. Cox proportional hazard analysis was used to evaluate the impact of age on survival.
Results: We identified 101,481 patients with gastric cancer with 10.5% being young, 41.6% middle aged and 47.9% elderly. Young patients were more likely to be Hispanic compared to middle-aged and elderly patients (24%, 10.8% and 7.9%, respectively; p<0.01) and were more likely to be uninsured (13.3%, 6.5% and 0.9%, respectively; p<0.01). Young patients presented more often with metastatic disease (46.3%, 37.0% and 27.6%, respectively; p<0.01), and high grade histology (79.9%, 67.4% and 61.7%, respectively; p<0.01). Young patients had increased 5-year relative survival compared to middle aged and elderly patients for both early disease (76.8%, 75.0% and 56.1%, respectively; p<0.01) and locally advanced disease (39.1%, 36.7% and 30.7%, respectively; p<0.01). For metastatic disease, young and middle aged patients had prolonged 5-year relative survival compared to elderly patients (5.2%, 5.2% and 3.0%, respectively; p<0.01). When adjusting for relevant patient-related, tumor-related, and treatment-related factors, young patients had favorable prognosis when compared to middle aged (HR=1.07, 95%CI: 1.04-1.1) and elderly patients (HR=1.44, 95%CI: 1.40-1.48).
Conclusion: While young patients were more likely to present with advanced disease, more aggressive histology, and lower socioeconomic status, younger age was associated with prolonged relative survival compared to their elderly counterparts when adjusting by stage and with prolonged overall survival when adjusting by other relevant clinical and treatment factors. Future studies are needed to determine if the differences seen in presentation and outcome between age groups are due to socioeconomic factors, ability to tolerate treatment, and/or inherent biology.