Clinical characteristics of colorectal cancer in Southern Iran, 2005
Subgroup: Volume 9, Issue 4
Date: October 2007
Type: Short Communication
Start Page: 209
End Page: 211
- M SaberiFiroozi Associate Professor of Gastroenterohepatology Research Center,Nemazee Hospital,Shiraz University of Medical Sciences, Shiraz, Fars, Iran
- D Kamali Gastroenterohepatology Research Center,Department of Internal Medicine,Nemazee Hospital,Shiraz University of Medical Sciences, Shiraz, Fars, Iran
- M Yousefi Gastroenterohepatology Research Center,Department of Internal Medicine,Nemazee Hospital,Shiraz University of Medical Sciences, Shiraz, Fars, Iran
- D Mehrabani Gastroenterohepatology Research Center,Department of Internal Medicine,Nemazee Hospital,Shiraz University of Medical Sciences, Shiraz, Fars, Iran
- F Khademolhosseini Shiraz, Fars, Iran ,
- ST Heydari Gastroenterohepatology Research Center,Department of Internal Medicine,Nemazee Hospital,Shiraz University of Medical Sciences, Shiraz, Fars, Iran
- K BlourianKashi Gastroenterohepatology Research Center,Department of Internal Medicine,Nemazee Hospital,Shiraz University of Medical Sciences, Shiraz, Fars, Iran
City, Province: Shiraz, Fars
Background: Colorectal cancer is the second leading cause of cancer-related mortality and represents a major public health problem in developed countries. The objective of present investigation was to determine the epidemiologic aspects and clinical characteristics of colorectal cancer in Shiraz, southern Iran.
Methods: This was a retrospective study carried out during 2000-2005, and comprised 491 subjects with pathologically documented colorectal cancer. They were registered in Fars Cancer Registry, affiliated to Shiraz University of Medical Sciences, southern Iran. A questionnaire including data on demographic information, histological types of cancer, site of primary cancer and metastasis were completed by trained interviewers.
Results: Among 491 subjects, 57.2% were male and the most common age was 65-75 years. Patients under 45 years of age represented 22.8% of all colorectal cancer cases while 32% were over 65 years old. Those with a history of cancer in their first-degree relatives included 26.9% of the patients. Adenocarcinoma was the most common reported histological type of cancer (96.1%). Among all subjects, 60.7% suffered from abdominal pain, 28.4% abdominal distention and 28.0% rectal bleeding. Other symptoms included diarrhea/constipation, nausea/vomiting, urogenital problems and mass sensation. The most common sites of metastasis were lung, brain and ovary.
Conclusion: The incidence of colorectal cancer showed a remarkable increase in our region that might be due to changes in life style, decreased physical activity, heavy smoking habits, dietary changes and increased prevalence of obesity. Considering the elderly as the most vulnerable and the growing trend towards involvement of younger subjects, more studies and screening seems to be essential.
Keywords: Characteristics; Colorectal cancer; Southern Iran
Colorectal cancer is one of the most common tumor types in the world with approximately 400,000 deaths annually.1 It is the second leading cause of cancer-related mortality and represents a major public health problem in developed countries.2,3 Compared to other regions, middle east is among the low incidence colon cancer areas. Nevertheless, a marked increase in the incidence of colorectal cancer was reported in southern Iran.4 Most cases are probably caused by environmental factors but genetic predisposition may affect the individual’s sensitivity to cancer and play an important role in about 5% of the cases.2,5 This study is performed to determine epidemiologic aspects and characteristics of colorectal cancer in southern Iran, Shiraz.
Materials and Methods
Fars Cancer Registry affiliated to Shiraz University of Medical Sciences in Shiraz, Iran, was established in 1971 to gather data on the prevalent cancers in Fars province, southern Iran as well as medical and demographic information from various medical centers throughout the province. The Registry is a hospital-based center and covers the patients in Fars province and neighboring regions. It is the major center for referral of patients suffering from cancer in southern Iran due to its equipped units, and specialists in different fields of cancer. All its registrars attended the locally organized courses in cancer registration. Among these, some also received advanced training in checking records of cancer cases from Surgical, Pathology, Oncology, Radiology and other related Departments and transferring the data to be recorded in Cancer Registry. The data provided from all patients are most complete and accurate and all pathology, radiological, chemotherapy and endoscopic documents are recorded. The epidemiologists and pathologists then recheck the data to exclude benign and suspicious cases and reclassify them if necessary. This is a retrospective study carried out during 2000-2005, and comprised 491 subjects with pathologically documented colorectal cancer who were registered in Fars Cancer Registry, affiliated to Shiraz University of Medical Sciences, southern Iran. A questionnaire including data on demographic information, histological types of cancer, site of primary cancer and metastasis were completed by trained interviewers. The collected data were analyzed using t-test and Chi-Square SPSS software (version 11.5, Chicago, IL).
Among 491 subjects, 57.2% were male and 42.8% were female. The mean age of patients was 55.11 years. The most common age group was 65-75 years. Those with a history of cancer in their first-degree relatives, constituted 26.9% of the patients. The most common reported histological type of cancer was adenocarcinoma (96.1%). In terms of differentiation, well-differentiated (43.7%) and poorly differentiated types showed higher prevalence, whereas the moderately differentiated type was found in 22.97% of subjects. Among all patients, 60.7% presented with abdominal pain, 28.4% abdominal distention, 19% diarrhea or constipation and 17% nausea and vomiting. Rectal bleeding along with sign and symptoms of anemia were present in 28% of patients with 15.7% complaining of urogenital problems. Mass sensation was reported in 3.4% of the subjects. The most common sites of metastasis were lung (99.5%), brain (99.5%) and ovary (99.2%). Patients under 45 years of age comprised 22.8% of all colorectal cancer cases while 32% were over 65 years- old.
Rate of colorectal cancer varies considerably according to geographic regions. The disease is common in USA, Western Europe, Australia and Scandinavia but it is relatively uncommon in Asia, Africa and South America.1 Compared to western countries, the incidence of colorectal cancer is low in Iran, though it shows a remarkable increase during last decades.4 The incidence of colorectal cancer increases with age. Risk of colorectal cancer was reported to increase after the age of 40 and sharply after 50.4 This pattern was also observed in our study, in which the most common age group was 65-75 years. In this regard, during 70s, the most common age group was 71-80 years and in the 90s, the most prevalent age was 40-50 years.2 The mean age of subjects in our study was 55.1 years compared to 63 and 52.8 years in the 70s and 90s, respectively.4 The changes may be due to increased use of colonoscopy leading to an early detection of tumors. The mean age of our colorectal cancer patients was similar to a median age of 55.3 years reported by Xu et al.6 We found the male to female ratio to be 1.34:1 which is slightly lower than that observed in a study on 3870 colorectal cancer patients in China with a male to female ratio of 1.42:1.6 Qing et al. also reported that rate of colorectal cancer was higher among men than women and suggested that hormone replacement therapy may reduce the incidence of this cancer in women. Female sex hormones affect cholesterol metabolism, which in turn affects bile acid production, a pathway, linked to the development of colorectal cancer.7
In our study, 26.9% of patients had history of cancer in their first-degree relatives. Similarly, a positive family history of colorectal cancer was observed in 10 to 15 percent of the patients in the Netherlands.2 Other authors have also stated that the relatives of such patients could be at increasing risk of colorectal cancer.8
Our Finding showed adenocarcinoma to be the most common cancer type in our region which is compatible to other studies conducted in Kurdistan, Western Iran,9 Gorgan north of Iran,10 and Tehran, the capital city of Iran.11 Studies from China revealed similar results.6 According to Sheidan et al., colorectal adenocarcinoma has been the third most frequent cancer in the Grand-Duchy of Luxembourg since 1994.12 In a study on cancer of the colon and rectum in Jamaica, most of the tumors were well or moderately differentiated adenocarcinomas.13 We, however, found the well and poorly differentiated types to be most prevalent.
In our study, the most reported symptom was abdominal pain (60.7%), which was also the predominant symptom in developed countries.14 In contrast to our results; Sarmast et al. reported hematochezia as the most common complaint.15
Previous research showed that liver was the most common site of metastasis from colorectal cancer.16 However, we found lung, brain and ovary to have the highest frequency of metastasis. We can conclude that the incidence of colorectal cancer showed a remarkable increase in our area, which may be due to changes in lifestyle along with decreased physical activity and heavy smoking habits.4 Additionally, dietary habits including high fat and low fiber diet intake and increased prevalence of obesity may be considered as other causes.17 Considering the elderly as the most vulnerable, and the growing trend towards involvement of younger subjects, further studies and screening seems to be essential.
- Li M, Gu J. Changing patterns of colorectal cancer in China over a period of 20 years. World J Gastroenterol 2005;11(30):4685-4688.
- De Jong AE, Vasen HFA. The frequency of a positive family history for colorectal cancer: a population-based study in the Netherlands. Netherlands J Med 2006; 64(10):367-70.
- Rougier P, Mitry R. Epidemiologic, treatment and chemoprevention in colorectal cancer. Ann Oncol 2003; 14(suppl 2):ii3-ii5.
- Hosseini SV, Izadpanah A, Yarmohammadi H. Epidemiological changes in colorectal cancer in Shiraz, Iran: 1980-2000. ANZ J Surg 2004;74:547-549.
- Chen K, Cai JI, Liu XI, Ma XY, Yao KZ, Zheng S. Nested case-control study on the risk factors of colorectal cancer. World J Gastroenterol 2003;9(1):99-103.
- Xu AG, Jiang B, Zhong XH, Liu JH. Clinical epidemiological characteristics of 3870 cases of colorectal cancers in Guangdong region. Zhonghua Nei Ke Za ZHi 2006;45(14):9-12.
- Qing SH, Rao KY, Jiang HY, Wexner SD. Racial differences in the anatomical distribution of colorectal cancer: a study of differences between American and Chinese patients. World J Gastroenterol 2003;9(4):721-725.
- Bradshow N, Holloway S, Penman I, Dunlop MG, Porteous MEM. Colonoscopy surveillance of individuals at risk of familial colorectal cancer. Gut 2003;52:1748-51.
- Molanaie N, Rahimi E, Aiobi S. Epidemiology of colorectal cancer in Kurdistan Province during 1995-99. J Kurdistan Med Sci 2000;17(5):25-22 (In Persian).
- Semnani SH, Kazemi-Nezhad V, Abdollahi N. Epidemiologic aspects of colorectal cancer in Gorgan. J Gorgan Med Sci 2003;12(5):13-18 (In Persian).
- Jalali SA, Kordjazi I, Jaladi SM. Epidemiological characteristics of colorectal cancer in patients referred to Imam Khomeini Hospital during 1481-2001. J Iranian Med Sci 2003;11(43):723-728.
- Scheiden R, Pescatore P, Wagener Y, Kieffer N, Capesius C. Colon cancer in Luxembourg: A national population-based data report, 1988-1998. BMC Cancer 2005;5:52.
- McFarlane NE, Rhoden A, Fletcher PR, Carpenter R. Cancer of the colon and rectum in a Jamaican population: diagnostic implications of the changing frequency and subsite distribution. Wed Indian Med J 2004;53(3):170-3.
- Pahlavan PS, Kanthan R. The epidemiology and and clinical findings of colorectal cancer in Iran. J Gastrointest Liver Dis 2006;15(1):15-19.
- Sarmast-Shooshtari MH, Najibpoor N, Mohammadi-Asl J. Clinical characteristics of colorectal cancer in Razi and Golestan hospitals of Ahwaz 1992-99. J Med Sci 2002;33(6):50-55 (In Persian).
- Primrose JN. Treatment of colorectal metastasis: surgery, cryotherapy or radiofrequency ablation. Gut 2002;510:1-5.
- Ghassemi H, Harrison G, Mohammad K. An accelerated nutrition transition in Iran. Public Health Nutr 2002;5:149-55.