Discussion
The CIRs and ASIRs of GC cases among the Saudi population must be tracked and kept current for all Saudi regions. The purpose of this study was to investigate the CIR and ASIR patterns of GC in Saudi Arabia from 2004 to 2017. According to the PubMed database, this is the first descriptive epidemiological research on the spatial/temporal distribution of GC among men and women in different regions of Saudi Arabia. It explores the actual state of the GC trend and the relevance of the disease in the population of Saudi Arabia.
From 2004 to 2017, the overall number of GC cases among Saudi men and women was 175 and 110 (7.1%), respectively. In addition, the overall number of confirmed cases of GC between 2004 and 2017 by age group of Saudi males and females were recorded, as the disease occurred in a significant percentage among those aged 50 years and older (Male: 83.3%, Female: 70.9%), whereas the age group younger than or equal to 49 years was less affected by GC (Male: 16.7%, Female: 29.0%). These findings are similar with those of other studies indicating that the median age of diagnosis for GC is 72 years old and that roughly 10% of gastric carcinomas are diagnosed in patients 45 years of age or younger.10-12
In this study, the incidence of GC was observed to be higher in males than in females. From 2004 to 2017, the CIR and ASIR of GC were twofold greater in Saudi men than in women. Globally, the incidence of GC varies by sex and geographical location. It is more prevalent in men than in women, and the risk of developing it rises with age.13In the United States, the recent studies indicates that the most major risk factor for the development of GC is male gender, with a ratio 2:1 male to female predominance.14 As well as, in the developed countries, men are 2,2 times more likely than women to be diagnosed with GC.15 Therefore, other studies indicate that male gender is a significant predictor of GC. In addition, Yang et al.16 found in their research of the survival rates of patients with metastatic GC that male patients had poorer survival rates than female patients.
In Saudi Arabia, the ASIR trend of GC among Saudi men and women has dropped steadily from 2004 to 2017. Similarly, over the past several decades, the incidence rates of GC have decreased gradually throughout the majority of the world including the United States (Figure 7).1 &17 Increasing hygienic standards, enhanced food preservation, increased intake of fresh fruits and vegetables, and Helicobacter pylori eradication could explain this downward trend.1&18
Our results indicates that male and female Saudis in Riyadh, Najran, and the Eastern region had the highest overall ASIRs for GC from 2004 to 2017. This suggests that males and females in Riyadh, Najran, and the Eastern region of Saudi Arabia are exposed to a significant risk factor for GC. In contrast, men and women in Jazan, Saudi Arabia, were the least affected by GC, indicating that they were more exposed to GC protective factor than persons in other regions of Saudi Arabia. However, a further epidemiological study should be conducted in the region of Riyadh, Najran, and Eastern region to find out the potential risk factors that lead to the increase of ASIR of GC among Saudis men and women. Furthermore, the protective factors of GC in the Jazan region that contributed to the lower rates of GC, should be investigated.
In Saudi Arabia, the estimated ASIR for GC among both genders in 2020 was 2.7% per 100,000 people. The rate is significantly lower compared to other countries. Oman had the highest rate of GC among both genders in the Arabian Gulf, at 8.0 per 100,000 people; this rate was 2.9 times greater than Saudi Arabia (Figure 8). Furthermore, the ASMR of GC was observed in Saudi Arabia at a rate of 2.1 per 100,000 people among both sexes. Compared to other Arab countries, this mortality rate was slightly lower (Figure 9). However, Oman had the greatest ASMR of GC among both genders, at 6.9 per 100,000 people, which was 3.2 times greater than Saudi Arabia. The results of this study also indicate that the overall ASIR of GC is extremely low in Saudi Arabia compared to Mongolia (32.5 per 100,000 people), Japan (31.6 per 100,000 people), and Korea (27.7 per 100,000 people); these rates were 9 to 10 times higher than in Saudi Arabia.9
This study investigates the actual distribution of GC in Saudi Arabia. It helps other researchers in formulating a new hypothesis regarding the potential risk-protective factors of GC among male and female Saudis residing in different regions. However, these studies have some limitations, including the absence of a comparison group and the inability to evaluate the statistical association between factors.19 In this research, the average death rates of GC in various regions of Saudi Arabia could not be determined since the SCR reports lacked information on the number of GC-related deaths.