Association of Recommended and Non-Recommended Food Score and Risk of Bladder Cancer: A Case-Control Study.

ABSTRACT

Bladder cancer (BC) is the ninth most common cancer in the world. Dietary patterns and diet quality could reduce exposure to carcinogenic factors postulated to increase the risk of BC. The main objective of this study was to investigate the associations of Recommended Food Score (RFS) and Non-Recommended Food Score (n-RFS) with the risk of BC among Iranian adults.This is a hospital-based case-control study, conducted at three referral hospitals in Tehran, the capital of Iran. Cases consisted of 103 histologically confirmed BC patients, aged greater than 45 years. Age-matched controls (n = 200) were selected from the same hospital where cases were recruited. Controls were patients with non-neoplastic diseases that are not related to smoking, or long-term diet modification. Dietary intake was assessed by a 168-item Food Frequency Questionnaire (FFQ), which was validated in Iran. Logistic regression tests were used to estimate the relationship between RFS and n-RFS with BC.The risk of BC decreased by 69% (OR = 0.31; 95% CI0.13-0.71) among participants belonging to the highest compared with the lowest quartile of RFS. After adjusting for age, sex, smoking, and total energy, a significant inverse trend was observed between the risk of BC and quartile of RFS. Regarding the n-RFS, also expressed as quartiles, subjects in the fourth quartile were at 2.7 times higher risk of having BC compared to participants in the first quartile (OR = 2.7; 95%CI 1.07-6.78).The findings of this study suggested that, adherence to RFS decreased the risk of BC. Additionally, a higher score of n-RFS may lead to an increased risk of BC. These findings could be used to develop evidence-based recommendations for the prevention of BC in Iran.