Relationships of colorectal cancer with dietary factors and public health indicators: an ecological study.

BACKGROUND: Colorectal cancer (CRC) is the third most common cancer in Iranian women and fifth in men. The aims of this study were to investigate the relation of dietary factors and public health indicators to its development. MATERIALS AND METHODS: The required information (2001-2006) about risk factors was obtained from the Non- Communicable Disease Surveillance Centre (NCDSC) of Iran. Risk factor data (RFD) from 89,404 individuals (15-64 years old) were gathered by questionnaire and laboratory examinations through a cross sectional study in all provinces by systematic clustering sampling method. CRC incidence segregated by age and gender was obtained from Cancer Registry Ministry of Health (CRMH) of Iran. First, correlation coefficients were used for data analysis and then multiple regression analysis was performed to control for confounding factors. RESULTS: Colorectal cancer incidence showed a positive relationship with diabetes mellitus, hypertension, lacking or low physical activity, high education, high intake of dairy products, and non-consumption of vegetables and fruits. CONCLUSIONS: We concluded that many dietary factors and public health indicators have positive relationships with CRC and might therefore be targets of preliminary prevention. However, since this is an ecological study limited by potential ecological fallacy the results must be interpreted with caution.

Relationships between breast cancer and common non- communicable disease risk factors: an ecological study.

BACKGROUND: Breast cancer is one the most common cause of cancer-related deaths among women worldwide. The aims of this study were to investigate the impact of dietary factors and health status indicators on breast cancer (BC) incidence. MATERIALS AND METHODS: Risk factor data (RFD) of 89,404 individuals (15-64 years old) were gathered by questionnaire and laboratory examinations through a cross sectional study from the Non- Communicable Disease Surveillance Centre (NCDSC) of Iran. BC incidences of all provinces through 2001-2006 segregated by age and gender were obtained from the Cancer Registry Ministry of Health (CRMH). RESULTS: A significant positive relationship was seen between diabetes mellitus, fish consumption, percent of academic education and non-consumption of fruit, and breast cancer in women. However, non fish consumption, percent age illiteracy and taking fruit showed a significant negative relationship with the incidence of breast cancer. In addition, multiple linear regression analysis showed associations among percentage with academic education, fruit consumption and diabetes. CONCLUSIONS: We conclude that dietary factors such as fish and fruit consumption, dairy products, health status indicators, academic education, and some diseases like diabetes mellitus can affect the BC incidence, although the results of ecologic studies like this must naturally be interpreted with caution.