ABSTRACT
BACKGROUND AND OBJECTIVES: Breast cancer is a major threat to women's health. Evaluation of the changes in trend of the incidence rate provides valuable information for the assessment and planning of development indicators of each country. The aim of the present study was to apply the JoinPoint regression model for determining changes in the trend of the breast cancer incidence rate in Isfahan. MATERIALS AND METHODS: In this cross-sectional study, 3640 women with breast cancer referring to oncology and radiotherapy departments of Seyed-al-Shohada and Milad cancer treatment centers of Isfahan during 2001-2010 were studied and sampling was not done. Joinpoint regression model was used to investigate the pattern of breast cancer incidence rate. Response and independent variables were the natural logarithm of the age-standardized incidence rates and year of diagnosis of breast cancer, respectively, in which various levels of cancer tumor characteristics (P < 0.05) were analyzed. RESULTS: The incidence rates increased annually in the age groups of 40-44 years (6.2%), 45-49 years (5.3%), and 55-59 years (5.3%). The trend of incidence rates in women with tumor size ≤2 cm (18.2%), well (moderately) differentiated tumor grade [8% (10.2%)], positive estrogen (progesterone) hormone receptor status [10.5% (6.9%)], and the proportion of positive lymph node to surgery node ≤25% (nonsignificant) was upward. CONCLUSION: The trend of incidence rates with tumor size ≤2 cm, well-differentiated tumor grade, moderately differentiated tumor grade, and positive estrogen and progesterone hormone receptors was upward. The pattern of breast cancer can help in cancer prevention and prognosis, and in selecting the best type of surgery.
ABSTRACT
BACKGROUND: Cancer incidence trends use by health officials in order to program evaluations and development of cancer control strategies. The trends of cancer incidence have used to evaluate programs and develop the cancer control strategies. The aim of this study is to analyze changes of breast cancer incidence trends in Isfahan city using joinpoint regression models. MATERIALS AND METHODS: The study was based on all cases of breast cancer reported among women residing in the city of Isfahan for the period 2001-2010. Age-standardized rates were calculated for each tumor characteristics, using the direct method. Joinpoint regression was used to provide estimated annual percentage change. RESULTS: A plot of the age-specific rates of breast cancer showed an increase in all age groups from 30 to 69 years and sharp increase in the incidence of breast cancer confined to estrogen receptor-positive and progesterone receptor-positive tumors and the significant change (2003) by progesterone receptor(-) tumors. The analysis by tumor size and grade, incidence rates decreased for tumors >5 cm by 10.6% since 2006.7 and for poorly differentiated tumor by 26.1% since 2007.8. No decrease in incidence was observed for group of proportion of positive lymph nodes to lymph node surgery ≥25%. The proportion of positive lymph node to surgery node ≤25% (nonsignificant) was upward. CONCLUSION: The trend of incidence rates with tumor size ≤2, well-differentiated tumor grade, moderately differentiated tumor grade, positive estrogen and progesterone hormone receptors was upward. The pattern of breast cancer can help to cancer prevention and prognosis, selecting the best type of surgery.
ABSTRACT
BACKGROUND: Breast cancer is the most common cause of death in women in the age range of 35-55 years. Each year, one or two cases of breast cancer per 1000 women are diagnosed as new cases. Despite the serious prognosis and high rate of morbidity, mortality, and pathogenicity, in the case of early diagnoses, the prognosis will be better. The aim of this study was to investigate the age trends in breast cancer patients with different sizes of tumors in Breast Cancer Research Center of Isfahan University of Medical Sciences in 2001-2010. MATERIALS AND METHODS: The information in radiotherapy and oncology of Isfahan University of Medical Sciences and Milad Hospital from 2001 to 2010 were coded and analyzed. Frequency of patients' age groups, tumor sizes and the year of cancer diagnosis were calculated. Correlation test was used for data analysis in statistical analysis in social science (SPSS) software version 18. FINDINGS: Among the 3722 patients with breast cancer, the highest relative frequency distribution, respectively was observed in the age of 40-49 years (34.4%), 50-59 years (26.6%), 30-39 years (17.7%), 60-69 years (13.2%), 20-29 years (2.5%), 70 years and older (5.2%) and less than 20 years. Relative frequency distribution of tumor sizes in a variety of 5 cm (T2) was with the frequency of 59.8%, and then 26% at 5 cm (T3), 10.5% at 2 cm (T1), 3.1% at T4 and 0.6 at In-situ, respectively. CONCLUSION: The investigation of age trends showed that diagnosis rate of breast cancer increased from 2001 to 2004. It reached its highest value in 2006 at the age range of 30-39 years. Then, the trend has been downward, and it has continued to decline until 2010, which could be the result of the equipping screening system and recording the malignant cases. 85.8% of the examined tumors in T2 and T3 group were visible and may be disturbing. Comparing the frequency distribution of the infected population showed that the highest incidence of breast cancer diagnosis were in the age range of 40-49 years. It seems that as long as the mass has not reached an obvious palpable state, it has not been diagnosed.
