Abstract 631: Association between dietary calcium intake and lung cancer risk in female non-smokers: A report from the Shanghai Women's Health Study

Abstract

Abstract Calcium has been implicated in carcinogenesis, especially through cell signaling and cell cycle regulation. Previous epidemiologic studies reported associations of calcium intake with the risk of colorectal, breast or prostate cancer. However, the studies investigating the association with lung cancer risk are limited, particularly among non-smokers. We evaluated the association of dietary calcium and other minerals that affect the calcium absorption with the risk of incident lung cancer among female non-smokers in the Shanghai Women's Health Study, a population-based cohort study of 74,941 women aged 40-70 years at enrollment (March 1997 to May 2000). Included in this analysis were 71,267 women who had never smoked and no prior history of cancer at baseline. Dietary intake was assessed using a validated quantitative food frequency questionnaire administered in person by trained interviewers. Cancer incidence and vital status were ascertained through annual linkage to the Shanghai Cancer Registry and Shanghai Vital Statistics data bases and biennial home visits. This analysis included 428 incident lung cancer cases accrued among the cohort members between April 1998 and December 2009 after the study enrollment. Cox proportional hazard regression was used to calculate the risk of lung cancer by quartiles of intake of calcium, magnesium, phosphorus or the calcium to magnesium (Ca: Mg) or calcium to phosphorus (Ca: P) ratios and by the use of calcium supplement, while adjusting for age, total caloric intake, income, occupation, passive smoking, history of asthma and body mass index. Intakes of calcium and phosphorus and the Ca: Mg and Ca: P ratios were inversely associated with the lung cancer risk; the corresponding risk reduction at the highest quartile comparing with the lowest was 34% for calcium, 45% for phosphorus, 38% for the Ca: Mg ratio and 25% for the Ca: P ratio (p for trend = 0.007, 0.02, 0.003 and 0.03, respectively). Calcium supplement was also associated with 33% significantly decreased risk. No association was observed for dietary magnesium intake (p for trend = 0.51). Our study provides one of the first evidence suggesting a possible role of calcium in lung cancer prevention among female non-smokers. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 631. doi:1538-7445.AM2012-631