ABSTRACT
Breast cancer is the most common cancer among women, and in 2002 it was expected that 636,000 new cases would occur in developed countries and 514,000 in developing countries. Although the incidence rate of this cancer in Asian countries is lower than in Western countries, whereas the incidence trend increasing rapidly in Asia. Using the data from the Cancer Registry System, this study was carried out to investigate the incidence trend during 2000-2005 in Iran and its six geographical areas. The incidence rates were standardized according to age-sex groups by Excel directly and confidence intervals is calculated for the point estimations by Stata11. The trends were analyzed separately based on gender, age groups for different provinces by Poisson regression in Stata11. The age standardized incidence rate in 2000 was 0.1 and 3.4 per 100,000 in males and females, respectively, reaching 0.5 and 16.7 per 100,000 in 2005. The incidence trends in all geographical areas of the country were increased despite the difference in the slopes. The sex ratio of male to female was 31.6 and the mean age of the patients was 49.4 (±12.6) years. The incidence of breast cancer in Iran was lower than the European and Asian countries but the trend is in rising. Although this increase is due to the increase in the prevalence of risk factors among Iranian population. Improvement in the coverage of the cancer registry system as well as the screening programs are important factors for these changes.
Subject(s)
Breast Neoplasms/epidemiology , Geography , Age Distribution , Female , Humans , Incidence , Iran/epidemiology , Male , Middle Aged , Prevalence , Time FactorsABSTRACT
BACKGROUND: As the third leading cause of death, cancers have a special place in the Iranian health system. Several studies have been done in some regions of the country with few years of follow-ups, but this was the first standardized study to investigate the incidence trends of colorectal cancer in Iran in a one-decade period. METHODS: The registered data for colorectal cancer cases in National Cancer Registry System were extracted from the Center for Disease Control & Management of Ministry of Health. The codes from 18 to 21 among cancers were selected for colon and rectum cancers. Incidence rates were directly standardized, using WHO population. The significance of incidence rate trends was tested through Poisson regression. RESULTS: In this study, 36,650 cases of colorectal cancer were observed for 10 years in Iran, which increased from 813 cases in 2000 to 6,210 cases in 2009. Gender ratio of men to women was 1.39. Significant increasing trends of colorectal cancer were observed during the period of the study. The standardized incidence rate increased from 1.6 per 100,000 persons per year in 2000 to 11.3 in 2009 in males (p<0.001), and it increased from 1.6 per 100,000 persons per year in 2000 to 10.9 in 2009 in females (p<0.001). CONCLUSION: Colorectal cancer has an increasing trend in Iran. The rising trend of colorectal cancer as well as other types of cancers is partially due to improvement in cancer registry systems in the early years of registry. Moreover, westernized lifestyle and an increase in environmental risks could explain this rising trend.
ABSTRACT
BACKGROUND: Colorectal cancer is a main leading cause of cancer death in western countries. Although many studies have been conducted on incidence trends all over the world in recent years, information regarding changes in incidence of colorectal cancer in Iran is insufficient. The present study of colorectal cancer in the west of Iran during recent years was therefore performed. MATERIALS AND METHODS: The registered data for colorectal cancer cases in National Cancer Registry System were extracted from the Ministry of Health and Medical Education, Center for Disease Control and Management. The codes from 18-21 among cancers were selected for colon and rectum cancers. Incidence rates were standardized directly using WHO population. The significance of incidence rate trends during 2000-2005 was tested through Poisson regression. RESULTS: 762 cases of colorectal cancer were observed during 6 years in this region, with a gender ratio of men to women of 1.2. It increased from 65 cases in 2000 to 213 cases in 2005 or from 1.5 per100,000 per persons per year to 4.8. Significant increasing trends were evident in Kermanshah and Hamadan provinces; however, change did not reach significance in Ilam and Kurdistan provinces. CONCLUSIONS: Colorectal cancer has an increasing trend in the west of Iran. Although it seems that the increasing rate of colorectal cancer is due to increasing of cancer risk factors, some proportion may be related to the improvement of surveillance systems in Iran.
