Cancer is the third main cause of death in Iran following coronary heart disease and road accidents. By ageing the population and reducing the number deaths due to accidents, cancer is gradually becoming the second cause of mortality in Iran. The incidence of almost all types of malignancies has alarmingly increased in the past two decades. It is estimated that more than 90000 of new cancer cases occur annually in Iran, and it is postulated this figure will double by the year 2020. However, in the absence of a nationwide population-based cancer registry, the burden of cancer can only be estimated by extrapolating from regional surveys. Overall age-standard incidence rate per 100 000 population according to primary site is 110.43 in males and 98.23 in females.
Despite the alarmingly growing number of affected cases in Iran, only a few national programs according to the World Health Organization (WHO) guidelines for cancer screening and prevention are active in Iran. ISCO, along with other medical societies and governmental organizations, are trying to establish a practical, standard and local (considering the differences in ethnicity, culture, etc) screening program to fight against cancer.
Ten most common malignancies in Iran | |||
Males | (%) | Females | (%) |
Skin (non-melanoma) | 14 | Breast | 23 |
Stomach | 11.9 | Skin (non-melanoma) | 10.1 |
Prostate | 9.4 | Colorectal | 8.5 |
Bladder | 9.1 | Stomach | 6.1 |
Colorectal | 8.3 | Esophagus | 4.4 |
Leukemia | 5.2 | Thyroid | 4.1 |
Lung | 5.2 | Leukemia | 4 |
Esophagus | 4.5 | Ovary | 3.3 |
NHL | 3.6 | Brain, nervous system | 2.9 |
Brain, nervous system | 3 | Corpus uteri | 2.8 |
Others | 25.8 | Others | 30.8 |
Cancer Registry in Iran
The first activities in Iran aiming at organizing cancer reporting were initiated in 1955, by the establishment of Cancer Institute in University of Tehran (now the Institute is part of Tehran University of Medical Sciences). The first report of cancer frequency data was prepared and published by the late Prof. Abdollah Habibi, an Iranian pathologist working at the Cancer Institute of Iran. This report included all cancer cases referred to the various pathology departments throughout the country since 1930, a duration of 30 years. This data, for the first time in Iran, was coded using the ICD system, and revealed a high frequency of cancers of the uterine cervix, skin, breast, esophagus, and lymphoma among females and skin, lymphoma, esophagus, larynx, and stomach among males. Although this report was never intended to be a true cancer registry, it has been well appreciated among those epidemiologists in Iran and the region who were interested in tracking changes in cancer frequency.
As a systematic surveillance, the cancer registry was initially established in 1969, after reports of a high incidence of esophageal cancer in the Caspian littoral of northern Iran. This registry was launched as a collaborative research agreement between the International Agency for Research on Cancer (IARC) and the Institute for Health Studies affiliated with the Tehran University School of Public Health. It started in the city of Babol in Mazandaran province, on the Eastern side of the Caspian Littoral, and subsequently extended to the Western province of Gilan. The aim of this registry was to study the high incidence of esophageal cancer in the province of Mazandaran. The published report of this study documented a very high incidence (as high as 150 cases per 100,000 population) of esophageal cancer among the people living in northern Iran, thereby extending the Asian esophageal cancer belt into the Caspian littoral and middle eastern region of Asia. The Mazandaran registry provided the basis for several analytical studies addressing the etiology of cancer in the high risk population of the Caspian littoral. Highlighted among these etiological findings was the contribution of the socio-ethnic ingredient of nutritional intake and habits to the high incidence of esophageal cancer in the area.
By 1971, this registry expanded its activity to cover the entire Caspian littoral: from the northern part of the province of Khorasan to the northern part of the province of East Azarbaijan. The expansion of the registry, further highlighted the peculiar cancer distribution in the Caspian littoral with a low incidence of upper GI (esophageal and stomach) cancers in the central littoral (the province of Gilan) and very high incidence of upper GI cancers in the eastern and western areas of the littoral, populated by two major ethnicities, Turkmens and Turks, respectively. This registry was able to generate population data for ten years (1968 to 1979) but its activity ceased in early 1980, and was then restarted in early 2000 with new aims and better logistics, enjoying advanced technology. In 1976, another population-based cancer registry was established in the province of Fars, and expanded its activity to the neighboring provinces of Khuzestan and Kermanshah to include vast areas in western Iran.
The activities of this registry were limited to the registration of histopathologically confirmed cases that had been referred to the pathology departments in the area, or cases from this area that had been referred for treatment at radiotherapy facilities in the city of Shiraz. The early data published by this registry reported high frequencies of skin, stomach, lymphoma, breast, cervix cancers and a low frequency of esophageal cancer among the population living in the central part of Iran populated mainly by ethnic Persians. The findings of this registry showed a picture of cancer prevalence different from that of the Caspian littoral. This registry is still publishing cancer frequency data, without reference to a defined population. These efforts were interrupted in the early 1980s due to the sociopolitical events in Iran, including the revolution and the war with Iraq. In 1984, the Parliament passed a bill mandating the report of all tissues “diagnosed or suspected as cancer tissue” to the Ministry of Health. The purpose of the bill was mentioned as promotion of “conducting epidemiologic research, regional prevention programs, and extracting statistical data on cancer patients”. Pathology centers are required by law to report all cancer cases according to International Classification of Diseases-Oncology (ICD-O).
The reports have been published regularly in Persian since 1999, and while in its first year, only 18% of all estimated cancer cases were reported, this rate increased to 81% in 2005. In 1998, Tehran Population-Based Cancer Registry (TPBCR), also known as Tehran Metropolitan Area Cancer Registry (TMACR), started to collect data from cases of cancer referred to the treatment and diagnostic facilities throughout the Tehran metropolis. This registry is a collaborative program of the Cancer Institute Research Centre and the International Agency for Research on Cancer, and is funded by different research centers and Tehran University of Medical Sciences. In 1992, Digestive Disease Research Center (DDRC), was established in Tehran University of Medical Sciences. The Center had investigations on upper GI cancers as one of its main missions, and was recognized as a WHO collaborating Center for research on Gastrointestinal Cancer in the year 2006. DDRC established new population-based cancer registries in Northern Iran in collaboration with IARC, Center for Disease Control in Iranian Ministry of Health and local medical sciences universities. The first of these registries was set up in Ardabil in the Northwest.
The Ardabil Cancer Registry office is currently run by Ardabil University of Medical Sciences and supervised by the DDRC, and it has been a member of IACR since 2005. This registry was extended to the east, including Gilan, Mazandaran and Golestan provinces. Northern Provinces were selected for 2 main reasons: the high incidence of upper GI cancers reported in these provinces and the availability of cancer registry data of this region from the 1970s. Another center was established in Kerman Province in the south central part of Iran. This registry aimed at providing a comparison site for cancer risk with the registries located in the North. These five provinces have a total population of about 9.5 million, and constitute about 16% of the total population of Iran. They also include three major ethnic groups in the country: Persian, Azari Turk, and Turkmen.
All of these registries are now run by the local universities of medical sciences. In addition, other population based cancer registries in central and southern provinces have been established by Shiraz and Semnan Universities of Medical Sciences. A series of reports from these registries have been published showing a declining incidence of squamous cell cancer of esophagus and small bowel lymphoma (immunoproliferative small intestinal disease) with concomitant rise in the incidence of colon, breast and distal esophageal adenocarcinoma. Another important finding has been a high incidence of gastric cardia adenocarcinoma especially in North western provinces.