Geographical variation in the incidence and mortality of stomach cancer and
association with the established risk factors in Iran
Kazem Zendehdel
1,2*
, Maryam Marzban1, Azin Nahvijou1, Nahid Jafari3
1. Cancer Research Center, Cancer Institute, Tehran University of Medical Sciences,
Iran
2. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet,
Stockholm, Sweden
3. Ministry of Health and Medical Education, Iran
Running title: Stomach cancer mortality in Iran
* Correspondence
Kazem Zendehdel, MD, PhD
Cancer Research Center, Cancer Institute
Tehran University of Medical Sciences
Tehran 13145-158, I. R. of Iran
E-mail: kzendeh@tums.ac.ir
Abstract
Background
Stomach cancer is the most common cancer in among Iranian men. We studied
geographical variation in the incidence and mortality rate of stomach cancer and its
association with established risk factors in Iran.
Methods
We used Iranian National Causes of Death Registry and estimated age-standardized
mortality rates (ASMR) of stomach cancer in 29 Iranian provinces, stratified by sex and
residential place (rural/urban). We performed systematic review of literature on the
prevalence of H pylori infection and retrieved prevalence of smoking, fridge use by the
households, and consumption of fruits and vegetables and studied their correlation with
pattern ASMRs of stomach cancer.
Results
ASMRs of stomach cancer among male and female were 15 and 8.1 per 100,000,
respectively. The highest and lowest mortality rates were observed in Kurdistan
(ASMR=29.1 per 100,000) and Hormozgan (ASMR=5.0 per 100,000) in the
northwestern and southern Iran, respectively. Male and rural residents had about twofolds higher ASMR compared to female and urban residents, respectively. Prevalence of
H pylori infection was about 90% in the high risk Ardabil province and 27% in the low
risk Sistan-Baluchistan province. Correlation of smoking between pattern of ASMRs of
stomach cancer and geographical distribution of smoking was 0.3.
Conclusions
Wide geographical variation and high mortality rate of stomach cancer in Iran, are likely
due to the distribution of established risk factors for stomach cancer, particularly H pylori
infection. Further epidemiological studies are needed to define the high risk subgroups
and cost-effective prevention program for stomach cancer.
Key words: Stomach Cancer, Mortality, Iran, Geographical variation
Introduction
Stomach cancer is the second cause of death due to cancer worldwide(1). Although
incidence rate of stomach cancer has decreased in the western world, its incidence and
mortality have increased or remained stable in the middle and low income countries (2).
Stomach cancer is usually diagnosed in a very advanced stages and its prognosis is poor.
Efforts for improving the treatment outcome of stomach cancer have been discouraging.
Therefore, stomach cancer prevention is prioritized, particularly in the high risk areas (3).
Stomach cancer is the most common cancer among Iranian men (4). While a high
incidence of stomach cancer were reported from different geographic areas in Iran(5, 6),
Ardabil province in the northwestern Iran was reported to be the highest incidence region
for stomach cancer in Iran, where the incidence rate was extremely high both in men
(ASR=50 per 100,000) and women (ASR = 24 per 100,000) (7) . On the other hand
ASRs of stomach cancer were considerably low in Kerman province in the central part of
the country (8). Screening and treatment H. pylori, the most important risk factor for
stomach cancer, is recommended as most reasonable risk reduction strategy for gastric
cancer prevention in high-risk populations by the Asia-Pacific consensus guideline in
2008(3), However, implementation of this recommendation is challenging due to
economical and practical reasons. Almost everyone is infected with H pylori infection in
the high risk areas. For instance, in high risk Ardabil province, H pylori infection was
estimated to be about 90% (9). Therefore, epidemiological studies are still warranted to
define high risk groups and explore new options for stomach cancer prevention.
Ecological studies and evaluation of the geographic pattern and epidemiology of stomach
cancer may help measure exact burden of stomach cancer in the country and identify high
risk regions for efficient interventions. Results of such a study will lead to appropriate
priority setting for research and cancer control programs. In this study we evaluated
geographic variations in the mortality rates of stomach cancer in Iran and studies
potential association of this variation with the distribution of the established risk factors.
Methods
Due to lack of validity and completeness of the nationwide cancer registry (10), we used
nationwide mortality registry to study the geographical pattern of stomach cancer in Iran.
We further, studies association of the observed variation with the established risk factors
in the country.
National Mortality Registry
After administrative planning, mortality data from different provinces compiled and
analyzed centrally by the Iranian ministry of health and medical education. The first
report of cause-specific mortality rate was published in 1998 based on mortality data
from four provinces. The registration activity extended to other provinces afterwards and
subsequent reports covered more areas. In year 2000-2003 the registry covered 10, 18,
19, and 23 provinces, respectively. In 2004 and 2005 the mortality registry covered
almost the entire country and reported the cause-specific crude mortality rates for 29
provinces. Tehran provinces (the capital) is not covered in the mortality registry yet (11).
The reports stratify the rate for male and female and also for residential places
(rural/urban). The classification of rural and urban areas was based on official
classification and definitions provided by the ministry of health. In this study, we used
cancer mortality data for the latter period (2004-2005).
National health survey
National health survey conducted in 1979 and 1989 in Iran. The survey studied
distribution of different risk factors including smoking, fridge ownership, consumption of
fruits and vegetables that were established risk factors for stomach cancer. Stomach
cancer occurs in age 45 years and older. We hypothesized that prevalence of risk factors
among people who were in their 40 years or older in 1989 should be correlated with the
observed pattern of stomach cancer ASMRs in 2006. We used aggregated data published
from the 1989 survey to evaluate association between pattern of stomach cancer ASMRs
and distribution of its risk factors in the country (12).
H pylori infection
We found no nationwide data to evaluate pattern of H pylori infection prevalence in the
country. We, thus, systematically searched English (PubMed, ISI) and Farsi (SID,
Magiran) databases and retrieved all the published data about prevalence of H pylori
infection in different part of Iran.. We only included papers that reported prevalence of H
pylori infection among healthy general individuals older than 40 years old. Studies that
evaluated the prevalence among the younger age groups and children were excluded from
the analyses. In addition, studies that evaluated H pylori infection among any disease
population were excluded. If a study evaluated H pylori infection among different age
groups, we estimated the prevalence among older age group based on data presented in
the papers. Since we came-up with a few numbers of papers that had the inclusion
criteria, we could only evaluate the potential role of H pylori infection in the pattern of
stomach cancer ASMRs qualitatively.
Statistical Analyses
We divided the number of stomach cancer mortality by total population of each province
and estimated the crude mortality rates of stomach cancer. Age-specific mortality rates
(ASMRs) were estimated for stomach cancer in 29 provinces in Iran, using age
distribution of the standard world population(13). We performed stratified analyses by
sex and residential place to figure out the mortality rates for men and women and
rural/urban residents exclusively. We further studied frequency of stomach cancer
mortality relative to the total cancer mortality in each region. The ASMRs were
categorized into four strata (<10, 10 to 14, 15-20, 20-24, and >25 per 100,000 in male)
and the estimates included on the country’s map using ArcGIS software version 9.2 in
order to provide graphical presentation of the mortality rate on the map.
We used Pearson correlation coefficient to evaluate the association between ASMRs and
the prevalence of smoking reported in the 1989 National Health Survey. We, further,
studied correlation of ASMRs pattern of stomach cancer in Iran and distribution of fridge
use among Iranian households and consumption of fruits and vegetables.
Results
Excluding 10% of the Iranian population living in the capital Tehran province, more than
10000 deaths due to stomach cancer reported in 2005 and 2006 in 29 provinces of Iran
(7000 in male and 3000 among female) (Table 1, Table2). Figure 1, presents pattern of
ASMRs for stomach cancer among male in 29 provinces. Regions located in the northern
part of the country particularly in the northwestern showed the highest ASMRs and the
provinces in the southern and central part of Iran showed the lowest ASMRs for stomach
cancer.
Overall, ASMR of stomach cancer was 15 per 100,000 and 23.6 percent of the cancer
deaths were due to stomach cancer among Iranian male (Table 1). The highest mortality
rate was observed in Kurdistan (ASMR 29.1 per 100,000) followed by East-Azerbaijan
(ASMR 27.6), West Azerbaijan (ASMR 26.1) provinces. In contrast, ASMRs of stomach
cancer were considerably low in southern parts of the country including Hormozgan
(ASMR 5.0) followed by Sistan-Baluchistan (ASMR 5.3), Bushehr (ASMR=5.5)
provinces. The mortality rate was also relatively low in the central part of the country
including Yazd (ASMR 7.1), Kerman (ASMR 7.1) and Khuzestan (ASMR 8.2), Isfahan
(ASMR 8.4) and Fars (ASMR 8.8) provinces (Table 1). Stratified analysis by residential
place showed that mortality rate the rural area (ASMR 21.5) was 2-fold of the rates in the
urban areas (ASMR 10.6). The mortality rate among male living in the rural areas of
Kurdistan provinces reached up to 45 per 100,000, while the ASMR among urban
residents was 20.4 per 100,000. However, ASMRs among rural and urban residents in
Sistan-Baluchesatn, Kerman, Yazd, Khuzestan, and Ghom provinces were almost equal.
Mortality rate of stomach cancer among women (ASMR 8.1 per 100 000) was about half
the rates among men (ASMR 15.0 per 100 000), although the relative frequency of death
due stomach cancer compared to all cancer deaths was similar among men and women
(22.1%) (Table2). The north to south decreasing gradient was also observed among
female. Kurdistan (ASMR 18.0), Ilam (ASMR 15.9), West-Azerbaijan (ASMR 14.6) and
East Azerbaijan (ASMR 13.6) had the highest ASMRs, while provinces located in the
southern and central part of the country including Hormozgan, Sistan-Baluchesatn,
Southern Khorasan, Isfahan, Bushehr, Kerman, and Yazd provinces had the lowest
ASMRs for stomach cancer among women, respectively.
Stomach Cancer Risk Factors
We found only eight published reports that studied prevalence of H pylori infection
among Iranian healthy population older than 40 years (Table 4). The highest prevalence
was observed in the high risk Ardabil province (89.2%) located in the northwestern
region (9) and the lowest prevalence (27%) was observed in the low risk SistanBaluchistan province in the southeastern of Iran (14). However, the prevalence was high
in Ghazvin (87.5%) and Kerman (62%-85 %) provinces that are medium (ASMR 10.8
per 100 000) and low risk ( ASMR 7 per 100 000) regions for stomach cancer,
respectively. (15, 16)
Analyses of 1989 national health survey, showed that tobacco smoking was modestly
correlated with the geographical pattern of stomach cancer mortality in Iran (=0.3).
Excluding a couple provinces that were outliers (high smoking prevalence but low
ASMR stomach cancer), increased the correlation to 0.5 (=0.5). Although there was no
significant association between owning the fridge and pattern of ASMRs, use of fridge
for food preservation in 1989 was significantly lower in the rural households (82%)
compared to urban (96%) households. We found no correlation between the use of fruits
and vegetables and pattern of stomach ASMRs in Iran.
Discussion
We found extremely high mortality rates of stomach cancer in Iran, particularly among
men living in the northwestern part of the country. We found a clear north to south
gradient in the mortality rate of stomach cancer, ranging from 29.1 per 100,000 in
Kurdistan province in the northwestern Iran to 5 per 100,000 in Hormozgan province in
the southern part of Iran. Similar pattern was observed for women. In addition to Ardabil
province that is known to be a very high risk area for stomach cancer in Iran (7), a large
area in the western part of the country exhibit high mortality rate for stomach cancer.
Among the others, Kurdistan province had the highest mortality rate of stomach cancer.
Despite several strengths and importance of our findings, this study was hampered by a
few limitations. First, mortality registry is still young in Iran and validity and
completeness of the data for cancer diagnosis was not evaluated yet. Stomach cancer in
the advanced stage with distant metastasis to other organs including liver, lymph node,
lung, bone, etc. might be misdiagnosed or type of cancer remain unknown in the death
certificate, leading to underestimation of the mortality rate. On the other hand, clinically
diagnosed cancers arising from other intra-abdominal organs like including colorectal,
hepatic, small intestine, pancreases, and etc. might be registered as stomach cancer in the
death-certificates and inflate the mortality rate. Although misclassification of cancer
types may exist, the mortality registry was established based on a systematic approach in
the and gradually extended from five to 29 provinces (11). We used the latest mortality
registry data, i.e. 2005 and 2006, when the registry covered almost the entire country and
when reached to relatively optimal accuracy and completeness. In addition, cancer is
chronic disease and the misclassification in the death registry is less likely compared to
other causes of death (17). Finally, because of central administration of the mortality
registry, the over or underestimations of cancer mortality in different geographical
regions should be non-differential. Although nationwide population n based cancer
registration is not exist in Iran, available reports from a population-based cancer registries
support our findings. Age standardized incidence rate (ASR) of stomach cancer was high
in Ardabil provinces (ASR 51.8 per 100,000) (7, 18) and the ASR was relatively low
Kerman (ASR 10.2) province (8). Therefore, notwithstanding some reservations, we
believe that the observed pattern and variations in the mortality rates of stomach cancer is
valid and reliable for policy making and priority setting.
About up to 6-fold excess mortality rate of stomach cancer in the northern part of Iran
warrant causal explanation. H pylori infection is the strongest established risk factor for
stomach cancer (19, 20). A pooled analysis of data from 12 nested case-control studies
showed a 6-fold excess risk of stomach cancer due to H pylori infection after 10 years of
follow-up (19). We may link the geographical variation in the risk of stomach cancer in
Iran to the variation in prevalence of H pylori infection. Although few studies have
evaluated the prevalence of H pylori infection in the healthy Iranian adult population,
available data support our expectation. A population based survey in the Ardabil
province revealed that 90% of people living in this high risk region. The same study
showed that 40% of the inhabitants live with atrophic gastritis in the high risk area,
supporting the role of H pylori infection in the high incidence rate of stomach cancer in
Iran (9).. We also found a significantly lower prevalence of H pylori infection in SistanBaluchesatn province(27%), a very low risk area for stomach cancer in southeastern part
of Iran (14). However, unexpectedly the prevalence of H pylori infection in the low risk
areas was relatively high in Kerman province 60-80% (15, 16)that is a low risk area for
stomach cancer. Therefore, further epidemiological studies are needed to uncover the role
of H pylori infection in the observed geographical variation in the risk of stomach cancer
in Iran. H. pylori strains containing the Cag-A gene are known to cause more extensive
inflammation in the stomach mucosa and antibodies against Cag-A persist long after
eradication [20 ,21]. Such study should also take into account the variation in the H
pylori variants throughout the country.
Other established risk factors of gastric cancer include tobacco smoking, low
consumption of fruits and vegetables, lack of fridge at home, low socioeconomic status,
male sex, high salt consumption, nutritional exposures, and positive family history of
cancer (21). There is no marked difference in the socioeconomic status of people living in
different part of Iran. Therefore, factors associated with the socioeconomic status cannot
explain this variation. Tobacco smoking increases the risk of stomach cancer. A metaanalysis showed that risk of stomach cancer among smokers compared to non-smokers
increase in the order of 1.5-2.5 with a somewhat higher summary estimate in males than
in females (22). Few case-control studies have shown association between smoking and
stomach cancer in Iran (23). Our relatively modest correlation between distribution of
smoking and pattern of stomach cancer ASMR in Iran support the role tobacco use and
risk of stomach cancer in Iran. However, it cannot explain the large variation observed in
the distribution of stomach cancer ASMRs in Iran.
Based on the national health survey in 1989, 97.7% of the households living in the urban
areas reported using the fridge, while only 81.3% of the households in the rural area used
fridge. This data may explain the considerable rural to urban difference in the stomach
cancer mortality rate 15 years later observed in our study. Currently, almost every remote
area in the country has access to electricity and people are using fridge at home. Although
the updated figures are not available, during the last 20 years, there have been major
development in the rural areas and almost 100% of the rural areas have access to
electricity. Although improvement of socioeconomic status will decrease the risk of
stomach cancer in future, the older cohort of people who have been exposed to the risk
factors in the previous decades will continue to experience a high incidence and mortality
rates of stomach cancer.
High risk areas in northern and northwestern part of country are usually mountainous
with clod and humid climate while the low risk areas in the central and southern part of
country have a dry and warm climate, leading to a large variation in life style, nutrition
habits, food preserving methods, etc. among people living in the high risk and low risk
areas. Further epidemiological data and comparison of the stomach cancer risk factors in
the high and low risk regions may explain the reasons behind a huge geographical
variation in the incidence and mortality of stomach cancer in Iran.
Recent Asia-Pacific consensus guideline recommended that screening and eradication H.
pylori infection is the most reasonable risk reduction strategy for gastric cancer
prevention in high-risk populations (3). In a cross sectional endoscopic survey, and
evaluation of H pylori with histology and rapid ureas test, about 90 percent of people
living in the high risk Ardabil province were H pylori infected (9). Based on the AsiaPacific guideline almost all Iranian male living in the high risk areas need to be
eradicated from H pylori infection, which is neither practical nor cost-effective. It might
be more reasonable to target a more high risk groups and select a limited population for
screening in these areas. There are proposals to measure levels of serum pepsinogen I
(PGI) and pepsinogen II (PGII) and use the low serum PGI and PGI/PGII ratio as a
marker to detect a high risk groups of people with gastric atrophic for further
investigation and active surveillance (23). Population based case-control and cohort studies
in the high risk areas may also uncover etiologic factors for stomach cancer in Iran and shed light
for designing an appropriate prevention program.
In conclusion, the large geographical variation and high mortality rate of stomach cancer
in Iran could be linked to H pylori infection, smoking, and living in the rural area, and
history of fridge use in the past. However, well-designed and large scale case-control and
cohort studies particularly in the high risk area are warranted to make a firm inference
about the role of these factors on etiology of stomach cancer. Until achieving an
appropriate and cost-effective screening program for stomach cancer, we suggest
enhancing primary prevention programs including awareness of general population about
stomach cancer risk factors, adapting a healthy lifestyle (i.e. improving the nutrition, decrease salt
intake, decrease tobacco consumption, etc.).
Acknowledgement:
This study was granted by Tehran University of Medical Sciences (No.: 87-01-51-6953).
We thanks health network development center, Ministry of Health and Medical
Education for generous help and providing the national mortality data.
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Table 1: Age Standardized Mortality Rates (ASMR ) of Stomach Cancer among Males in Urban and
Rural Areas of 29 Provinces in Iran from 2004 to 2005
Overall
Rural
Urban
Percentage
Population No, of
No, of
No, of
of all
ASMR
ASMR
ASMR
size
cases*
cases*
cases*
cancers
729,718
366
33.8
29,1
240
45,0
126
20,4
Kurdistan
1,458,781
611
28.8
27,6
351
40,0
260
21,6
West Azar
1,839,341
915
26.2
26,1
484
41,7
431
20,2
East
baijan
481,698
214
30.8
25,3
139
36,9
75
17,5
Zanjan
Azarbaijan
45.3
Kohgilouyeh
320,983
23,7
79
32,3
17
12,7
96
B,
401,865
139
27.4
21,2
90
26,3
49
18,7
Khorasan
617,342
225
33.3
21,0
160
33,8
65
12,1
Ardabil
North
431,644
132
31.7
18,9
78
24,1
54
16,4
Charmahal
278,566
79
24.0
18,0
43
23,9
36
17,3
Ilam
302,433
100
21.8
17,1
49
27,2
51
14,6
Semnan
792
27.6
17,1
Khorasan
2,809,403
540
33,8
252
9,5
Razavi
483
27.3
17,0
366
25,4
117
9,9
Mazandaran 146,6870
1,198,519
443
26.6
16,7
293
21,6
150
13,7
Gilan
873,692
229
27.1
15,5
127
21,6
102
13,7
Lorestan
682,367
207
22.1
14,3
124
19,9
83
12,2
Markazi
242
20.0
14,2
120
22,0
122
12,0
Kermanshah 957,325
856,837
225
27.0
13,0
150
20,6
75
9,2
Hamadan
536,904
96
17.7
12,0
6
8,4
90
13,8
Ghom
804,162
130
19.9
11,3
96
16,6
34
6,7
Golestan
583,869
104
18.9
10,8
56
14,9
48
9,7
Ghazvin
322,142
61
22.3
10,6
41
12,6
20
8,9
Khorasan
2,204,852
329
19.0
8,8
186
13,3
143
6,8
Fars
South
2,335,399
380
15.9
8,4
120
15,3
260
8,0
Isfahan
2,184,931
234
16.0
8,2
85
9,9
149
8,4
Khoozestan
1,353,867
149
14.4
7,1
74
7,7
75
7,3
Kerman
517,137
67
11.5
7,1
27
11,9
40
6,5
Yazd
468,062
38
10.7
5,6
17
6,5
21
6,2
Boushehr
1,221,240
74
23.6
5,3
34
4,9
40
7,3
Sistan
725,196
47
19.1
5,0
35
7,0
12
3,7
Hormozgan
7207
23.6
15,0
2997
21.4
4210
10.6
Iran**
28965145
*Number of cases for two years 2004 and 2005, but other estimates is presented as an average for one year
**Tehran Province was not included for estimation of the rate for entire country, since the data from the
capital was not available
Table 2: Age-Standardized Mortality Rates (ASMR ) of Stomach Cancer among Females in
Urban and Rural Areas of 29 Provinces in Iran from 2004 to 2005
Overall
Rural
Urban
No, Percentage
No,
No,
Provinces
Population
of
of all
ASMR
of
ASMR
of
ASMR
size
cases
cancers
cases
cases
710,438
194
31.5
18,0
136
31,8
58
9,7
Kurdistan
55
29.6
15,8
29
21,2
26
13,9
Ilam
267221
320
26.9
14,6
199
25,0
121
9,6
West
1414678
447
20.3
13,6
231
22,3
216
10,6
East
Azarbaijan 1764115
Azarbaijan
73
24.4
12,1
56
18,0
17
7,0
Khorasan North 409707
114
32.6
11,7
82
19,0
32
6,8
Ardabil
610813
136
26.8
11,4
78
18,1
58
8,3
Lorestan
842835
94
25.0
10,8
51
14,0
43
9,9
Zanjan
482903
67
30.9
10,8
25
8,6
42
13,9
Charmahal B.
426266
378
21.2
8,8
261
18,1
117
4,3
Khorasan
2783676
77
20.3
8,6
37
11,0
40
8,2
Ghazvin
559331
Razavi
32
37.7
8,5
28
12,9
4
2,8
Kohgilouyeh
313316
214
21.2
7,9
146
10,9
68
5,7
Mazandaran
1455562
119
17.7
7,8
60
12,6
59
6,4
Kermanshah
922060
108
18.8
7,5
60
10,4
48
6,8
Markazi
668890
42
15.6
7,3
24
15,8
18
5,1
Semnan
287309
191
21.2
7,3
126
9,5
65
6,0
Gilan
1206342
109
22.0
7,1
74
11,5
35
4,5
Hamadan
846430
53
14.7
7,1
1
2,5
52
8,5
Ghom
509833
58
14.3
5,5
47
9,0
11
2,2
Golestan
812925
185
17.0
5,4
103
8,5
82
4,0
Fars
2132026
130
14.2
5,0
37
5,2
93
5,6
Khoozestan
2090048
38
8.8
4,7
12
5,0
26
5,2
Yazd
473681
97
14.5
4,7
49
6,1
48
4,5
Kerman
1298546
27
9.1
4,6
15
6,9
12
4,1
Boushehr
418205
191
11.8
4,3
69
8,8
122
3,9
Isfahan
2223857
23
12.9
3,6
18
5,3
5
2,2
Khorasan_south 314278
38
19.4
3,3
20
3,4
18
3,9
Sistan
1184502
24
14.5
2,3
15
3,4
9
2,4
Hormozgan
678478
28108271
3634
22.1
8.1
2089
11.7
1545
5.6
Iran**
* number of cases for two years 2004 and 2005, but other estimates is presented as an average for one year
** Tehran Province was not included for estimation of the rate for entire country, since the data from the
capital was not available
Table 3: Prevalence of H pylori infection among Iranian general population older than 40 years and living in the different
provinces of Iran
Author, year
Area
Province
Risk of
Age
Sample
Prevalence
Stomach
size
Cancer
Malekzadeh R, 2004 (9)
Northwestern Ardabil
High
>40
1101
89.2
Sheikholeslami, 2004* (24)
Baba Mahmoudi F, 2001* (25)
Northwestern
North
Ghazvin
Mazandaran
High
High
>40
>40
120
NA
87.5%
75%*
Ghadimia R, 2004 (26)
Alizadeh AHM, 2009 (27)
Jafarzadeh A, 2006* (16)
Zahedi MJ, 2002* (15)
Metanat M, 2010 (14)
North
West
Central
Central
Southeast
Babol
Hamadan
Kerman
Kerman
Sistan-Blochestan
High
High
Low
Low
Low
Mean50
>40
41-60
>35
>30
130
570
60
113
85
79.7%
82%
85%
62%
27%
* The paper is in Farsi language and was published in the local journals.
]
Figure 1: Geographical pattern of age standardized mortality rate (ASMR) per 100,000
for stomach cancer among Iranian male (2005-2006). Note: There were no mortality
data for the capital Tehran province in the central part.