Abstract A35: Association between calcium and beta-carotene intake and risk of prostate cancer in Seoul Male Cohort Study
Authors: Shin Myung-Hee , Bae Jong-Myon , Lee Moo-Song , Kim Dong-Hyun , Li Zhong-Min , Ahn Yoon-Ok 
Published: October 2015

Abstract
Prostate cancer is a 5th common cancer among Korean male population, but the incidence is increasing rapidly (12.1% per year). The 5-year relative survival of prostate cancer in Korea is relatively poor (80.1% for 2001-2005 incident cases) compared to other developed countries (99.4%, 2001-2007 incident cases in SEER U.S.A), probably due to later stage at diagnosis. Dietary factors are strongly related to the risk of prostate cancer. Calcium and beta-carotene has been suggested to have a positive and an inverse association with the risk of prostate cancer, respectively. However, several recent studies showed no association with dietary calcium and either no or a positive association with bet-carotene, especially among smokers. We aimed to test the association between calcium and beta-carotene intake and the risk of prostate cancer in a Korean male population. Seoul Male Cohort was established in 1993. Members were recruited from the male beneficiaries of the Korean Health Insurance Company, who were aged 40-59 and living in Seoul. A lifestyle questionnaire survey was conducted through mailing. Dietary intake was measured using a quantitative food frequency questionnaire with 88 food items. Nutrient intake was calculated and the amount was categorized into quartiles (q1-the lowest quartile, q4-the highest quartile). Cancer occurrence was identified through data linkage to the Korean Central Cancer Registry and Korean Death Records. A total of 14,533 members were followed up until December 31, 2008, and 123 incident prostate cancer cases were identified. Multivariable hazard ratios (aHR) and 95% confidence intervals (95%CI) were calculated using Cox's regression model. There was no significant difference between prostate cancer patients and non-cancer cohort members in terms of initial age, family history, body mass index, alcohol intake, and smoking, whereas prostate cancer patients had higher education (p&lt;0.036). Higher calcium intake was not associated with prostate cancer (q4 vs. q1, aHR=0.98, 95%CI = 0.51-1.88, ptrend=0.81). Moderate, but not significant, risk increase by beta-carotene intake was observed (q4 vs. q1, aHR=1.60, 95%CI = 0.93-2.77, ptrend=0.06). Baseline smoking rate among cohort members was high (76%). Therefore, we observed the same result in a subgroup analysis with smokers only.
In conclusion, calcium intake did not increase the risk of prostate cancer, and beta-carotene intake may increase the risk of prostate cancer in a Korean male population.
Citation Format: Myung-Hee Shin, Jong-Myon Bae, Moo-Song Lee, Dong-Hyun Kim, Zhong-Min Li, Yoon-Ok Ahn. Association between calcium and beta-carotene intake and risk of prostate cancer in Seoul Male Cohort Study. [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr A35.