| Abstract|| |
Background: Gastric malignancy is one of the most common causes for cancer-related deaths. Reports from the west have shown a paradigm shift in the site of occurrence with malignancies of the gastric cardium increasing in frequency, reports which are contrary to information from the Middle East and South Asia. Aim: To determine trend changes in distribution of gastric malignancy between 1989 and 2004 in the southern state of Tamil Nadu in India. Materials and Methods: The study period was divided into four cohorts of four years each (1989-1992, 1993-1996, 1997-2000 and 2001-2004) for the analysis of the changes in trend for subsite specificity, age and gender predilection. Results: Clinically, there were no significant differences in the presenting symptoms or physical signs in the four cohorts. The antrum was the most common site of predilection, no site-specific change was noted and males continued to be more commonly affected of the two sexes. Gastric cancer was significantly higher above the age of 40 years in all the four subsites and cohorts. A decrease in the mean age was observed for men with cancers of the esophagogastric junction (OGJ) ( P < 0.0001) and the proximal stomach ( P < 0.0001), while junctional malignancy ( P < 0.0001), cancers of the proximal stomach ( P < 0.0001) and the antrum ( P = 0.03) tended to occur progressively later among women. Conclusion: No change in site specificity or gender predilection for gastric adenocarcinoma has been noted in the past 16 years. However, a gender-dependent paradigm shift in the mean age of presentation is discernible for cancers involving the OGJ, proximal stomach and antrum.
Keywords: Adenocarcinoma, stomach, trends
|How to cite this article:|
Cherian JV, Sivaraman R, Muthusamy AK, Venkataraman J. Stomach carcinoma in the Indian subcontinent: A 16-year trend. Saudi J Gastroenterol 2007;13:114-7
|How to cite this URL:|
Cherian JV, Sivaraman R, Muthusamy AK, Venkataraman J. Stomach carcinoma in the Indian subcontinent: A 16-year trend. Saudi J Gastroenterol [serial online] 2007 [cited 2019 Dec 6];13:114-7. Available from: http://www.saudijgastro.com/text.asp?2007/13/3/114/33461
Gastric malignancy is the second most common cause of cancer-related deaths worldwide. Major changes have been noted in the site of gastric cancer occurrence. The west has noted a paradigm shift with a steady increase being observed in the incidence of cancers of the gastric cardium and the proximal stomach and a decline noted in the incidence of cancers in the distal stomach.  The redistribution has been attributed to the reduction in H. pylori infection and the associated atrophic gastritis. 
Reports from Asian countries like Japan, Korea and Iran have been conflicting. The Japanese  and the Korean  populations have a predominance of noncardium gastric cancers while the Iranians have reported a trend similar to that in the west.  A recent study from the southern state of Kerala in India  showed that carcinoma of the distal stomach has remained predominant although a trend towards a proximal shift has been noted.
The present study was aimed to determine retrospectively, changes in site-specific distribution of gastric malignancy between 1989 and 2004 in Tamil Nadu, a southern state in India.
| Materials and Methods|| |
Details of 1719 patients with adenocarcinoma of the stomach were retrieved. Cancer recurrence after surgery and also those cancers that occurred after gastrojejunostomy for peptic ulcer disease were excluded. Age, gender, clinical presentation and duration of illness were recorded in a prestructured proforma. The site of the stomach tumor was recognized as involving one of the four sites, namely:
a. Junction, i.e ., tumour astriding the esophagogastric junction (OGJ)
b. Proximal stomach, i.e ., involving the cardium and / or fundus
The study period was divided into four cohorts of four years each, i.e ., 1989-1992, 1993-1996, 1997-2000 and 2001-2004 in order to note any change in trend. Changes in the site of occurrence were analysed using one sample chi square test. Changes in age and gender distribution across the four time periods were done using two sample Pearson chi square test. The subsite- and gender-specific changes in the mean age of occurrence was analyzed using one way analysis of variant F test (one way ANOVA F test) and post hoc analysis using Bonferroni t test. P values < 0.05 were considered significant.
| Results|| |
Clinically, there were no significant differences in the presenting symptom or in the physical signs in the four cohorts.
Time trends of gastric cancer at various subsites
There was a significant increase in the number of gastric cancers diagnosed at endoscopy in the four successive cohorts ( P = 0.001) [Table - 1]. A proportionate increase in the number was seen in all the four subsites. The sites of gastric cancer in order of decreasing frequency were: antrum (67.3%) followed by the body (23.3%), proximal stomach (5.6%) and OGJ (3.8%).
Time trends in age
Gastric cancer rates, both overall and subsite-specific were significantly higher above the age of 40 years in all the four cohorts and the variations noted were not statistically significant for cancers of the proximal stomach, body and antrum. However, a statistically significant increase in the number of patients affected below the age of forty years was seen in cancers involving the OGJ ( P = 0.008) [Figure - 1]. A significant increase across the four cohorts was seen in the mean age of occurrence for antral malignancy while there was a significant decline for junctional malignancy. No change in trend was seen in cancer involving the proximal stomach and body.
In men, while there was an increase in the mean age of occurrence from 53.72 ± 10.91 years to 55.50 ± 12.68 years for antral malignancy ( P = 0.07, nonsignificant (NS)), a significant decrease in the overall mean age of occurrence was noticeable for cancers involving the OGJ and the proximal stomach.Gastric cancer occurred earlier among women than in men in all the four subsites with a significant rising trend in the mean age of occurrence for cancers of the OGJ, proximal stomach and antrum. A declining trend was noted for cancers involving the body of the stomach [Table - 2].
Time trends in gender predilection
Gastric cancers predominantly affected males with an overall ratio of 3 ( P = 0.001). The male : female ratio of the cancers involving the proximal stomach, body, antrum and OGJ was 3, 2, 3 and 4 respectively. No significant change in the gender ratio was noted across the different subsites during the study period [Figure - 2].
| Discussion|| |
The present study sought to discern the changes in trends of gastric carcinoma in a South Indian population. In contrast to western countries like the USA,  Switzerland,  Sweden  and the United Kingdom,  the overall incidence of adenocarcinoma of the stomach in the present study has shown a significant rise rather than a decline, reports similar to those from the south Asian countries of Japan  and Korea. 
A Swedish study  conducted between 1970 and 1985, had shown an increase in the age-standardized rate of cancers of the gastric cardium in men from 1.9 per 10 5 in 1970 to 1973 to 3.5 per 10 5 in 1982 to 1985 (58% increase) corresponding to a mean annual increase of 2.5%. In women, the age-standardized rates had increased from 0.5 per 10 5 in 1970 to 1973 to 0.8 per 10 5 in 1982 to 1985 corresponding to a mean annual increase of 0.9%. The relative percentage of cancer located at the gastric cardium had increased in men from 5.1% in 1970-1971 to 11.2% in 1984-85 and in women from 2.6 to 6.1%.
In the present study, the distal stomach has continued to be the most common site of affliction and malignancies of the proximal stomach including the OGJ are static or low, an observation contradictory to the rising incidence of adenocarcinoma of the gastric cardium in the west, Iran,  Sweden  and Kerala, a state in India. 
A population-based study from the Swiss Canton of Vaud  had shown no increase in incidence of adenocarcinoma of the gastric cardium between 1976 and 1987, an observation similar to the French study.  Two major studies from south Asian countries of Japan  spanning thirty years and a hospital-based study from Korea  also had not shown an increasing trend in cancers of the gastric cardium.
Age-wise trend changes in carcinoma of the stomach have been reported worldwide. In the USA  between 1974 and 1994, the trends for gastric adenocarcinoma had varied by age, being more pronounced among older men. While the increase in adenocarcinoma of the gastric cardium was 20% for ages < 65 years, the rise was 60% for those > age of 60 years. Similar increase in trend with increasing age was noticeable in the Swedish study.  In men, the trend was most pronounced in the age groups of 50-59 years and > 80 yrs, with a mean annual increase of 4.3 and 4.5% respectively. In women, the mean annual increase in the age-specific incidence rates was 2.3% in the 60-69 years' age group.
In the present study, the overall and subsite-specific gastric cancer rates were significantly higher in persons above the age of forty years. Significant changes were noted in the mean age of occurrence of the gastric cancer at various subsites and also in the two sexes. In general, antral malignancies occurred at a later age of 54.79±12.49 in the fourth cohort, compared to 52.35±11.34 years in the first cohort. Adenocarcinoma involving the OGJ occurred at an earlier age, while no change was discernible in cancers of the proximal stomach and body.
Women developed gastric cancer earlier than men, in all the four subsites and cohorts. There was an increase in the mean age of occurrence of gastric cancer in women, more so for cancers of the OGJ, proximal stomach and the antrum. Consequently, the differences in mean age between the two genders have shown a fall in all the subsites, except in the body of the stomach. Reports from the neighboring state of Kerala have not shown a significant time trend change in the subsite-specific mean ages between 1982 and 2001.
The male : female ratios in studies from Kerala,  Sweden  and Korea  were 1.97:1, 4:1 and 3.78:1 respectively. There was no overall or subsite-specific trends in the male : female ratio in the three studies; also no change was noted from the Iranian study. The present study has also shown gastric cancer to be a predominant disease in males (ratio = 2.74:1) and the male predilection is more pronounced in cancers involving the proximal stomach and OGJ: 3.21:1 and 3.64:1 respectively. No significant changes in the gender ratios were noted across the various subsites.
In summary, the present retrospective study on trends in stomach carcinoma from a south Indian population has shown no change in the gender predilection and site specificities of carcinoma of the stomach. The antrum continues to be the most common site for malignancy. A paradigm shift in the mean age of presentation is discernible and is gender-specific at least for cancers involving the OGJ, proximal stomach and antrum.
| Acknowledgements|| |
We thank Mr. A. Vengatesan, lecturer in statistics, Clinical epidemiology unit, Stanley Medical College for statistical assistance.
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Jijo Velliyappillil Cherian
Velliyappillil House, Thottumukkom P.O, Areacode, Kozhikode, Kerala - 673 639
Source of Support: None, Conflict of Interest: None
[Figure - 1], [Figure - 2]
[Table - 1], [Table - 2]