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i I I A MATCHED CASE-CONTROL STUDY OF THE RELATIONSHIP BETWEEN BETA-CAROTENE INTAKE AND LUNG CANCER Tan Ai-Jun, He Shang-pu, Huang Ming-xi, Li Guo-Guang and Shi Lu-yuan I I I I F I I I I I I E I I Tongji Medical University, Wuhan, China In order to evaluate the relationship between dietary intake and serum level of beta-carotene and lung cancer risk, a 1:1 matched case-control study of 156 newly histologically diagnosed primary lung cancer patients and 156 general patients (without tumors, respiratory, or other related diseases) was conducted in Wuhan. Three ml of venous blood were collected, and all cases and controls were asked to participate in a nutritional assessment and to answer a food frequency questionnaire containing 64 items on 11 kinds of foods. Subjects were instructed to recall dietary habits during the year prior to their first recognition of any symptoms associated with their diseases. Nutrient intake from foods was calculated from the annual intake of various food items by reference to a food composition database. The findings showed that there was a statistically significant difference between dietary intake of beta-carotene in cases and controls (2877.13 ± 393.43 vs 3445 ± 430.98 µg/day), and serum level as well (25.69 ± 5.57 vs 32.26 ± 5.02 µg/dl). Using conditional logistic regression analysis, an inverse association was found between dietary intake and serum concentrations of beta-carotene and lung cancer risk. When controlling for the potential confounding effects of cigarette smoking and alcohol consumption, a significant linear trend of lower dietary carotene intake and higher lung cancer risk was observed. '

I Table 1. Odds Ratio (OR) Linear Trend Test for Lung Cancer by Histologic Subtypes (Controlling for Cigarette Smoking) According to Levels of Dietary Carotene Intake < 104 > 3282 13 1.00 11 1.00 3 1.00 62 2960-3282 15 2.04 9 1.45 3 1.86 35 < 2960 20 4.54 8 2.15 2 2.06 21 (Pxl trend=0.00) (PX2 trend=0.14) (PXZ trend=0.30) z 104 > 3282 4 1.00 8 1.00 8 1.00 20 2960-3282 9 5.00 6 1.67 9 2.50 9 < 2960 16 12.33 4 1.67 8 3.33 6 (PXZ trend=0.00) (PXz trend=0.43) (PXz trend=0.04) 77 46 33 156 Adjusted OR(95% CI) 100 1.00 1.00 2.61(1.81-3.78) 1.52(0.92-2.51) 2.21(1.34-3.63) 6.14(3.05-12.35) 1.98(0.88-4.47) 2.82(1.47-5.39) (PXZ trend=0.00) (PxZ trend=0.10) (PXZ trend=0.04) 1. Daily cigarette consumption X no. of years smoked. 2. Unit: µg/day I I I I I I I I I I I I I I NI 0 tp ~ v tp W ~ I -2- N I I

a I I I I ' I I I I I I Table 2. Odds Ratio (OR) Linear Tread Test for Lung Cancer by Histologic Subtypes (Controlling for Alcohol Consumption) According to Levels of Dietary Carotene Intake Index' i Intake2 I No.. L OR I No. I OR . . I No. I OR I No. <25 > 3282 9 1.00 9 1.00 5 1.00 46 2960-3282 12 1.92 3 0.48 5 1.44 32 <2960 16 2.92 3 0.55 9 2.96 28 (FIX2 trend =0.02) (P~~ trend =0.31) (PX2 crend= 0.06) z 25 > 3282 8 1.00 18 1.00 5 1.00 30 2960-3282 14 3.75 11 1.31 2 0.86 14 < 2960 18 11.25 2 0.56 7 7.00 6 (PXZ trend =0.00) (Px2 trend =0.81) (PXz trend= 0.01) 77 46 33 156 Adjusted OR(95 % CI) 1.00 1.00 1.00 2.59(1.7 1-3.93) 0.91(0.76 -1.87) 1.19(1.06-1. 32) 4.86(2.4 3-9.72) 0.55(0.17- 1.78) 4.10(1.69-9.9 2) (PX' trend=0.00) (PXz trend=0.10) (PXz trend=0.04) I I I I 1. Alcohol consumed per day X drinking years. 2. Unit: µglday tv 0 co , s -4 3 C* W .p ~ W