Incidence Trends of Gastric Cancer in Southern Iran: Adenocarcinoma and Non-Cardia Gastric Cancer Are More Rising Among Younger Ages

BACKGROUND Gastric Cancer (GC) is still one of the major causes of cancer mortality. Due to health-related transitions, the epidemiology of GC subtypes may change. These changes may have profound effects on clinical approaches as well as on public health management of GC. Iran, as a developing country, has experienced huge demographic and epidemiological transitions during the recent decades. This study aimed to investigate the subtype-specific population-based incidence trends of GC in southern Iran. METHODS We used data on GC incidence in southern Iran during 2001-2015. Data preparation and subtype grouping were done based on the ICD-O-3. The trends of Age-Standardized incidence Rate (ASR), truncated ASRs, incidence rate of adenocarcinoma, and cardia GC, and age-gender specific rates were analyzed using joinpoint regression modeling. Annual Percentage Change (APC) and its 95% Confidence Intervals (CIs) were estimated. RESULTS Overall APC was estimated as 7.2 for males and 8.7 for females. The estimated APCs for the trends of overall GC, and gastric adenocarcinoma were stable in both genders during 2009-2015. Nonetheless, cardia GC showed increasing trends in both genders. The estimated APCs for the trends of non-cardia GC was also stable. CONCLUSION The overall trends of the GC incidence in southern Iran were stable during the past decade. However, significant and different changes have occured in the pattern of GC. Thus, etiological and prognostic studies are needed for the improvement of GC management in Iran.