Vitamin D–Binding Protein and Risk of Renal Cell Carcinoma in the Cancer Prevention Study-II Cohort

DOI: 10.1158/1055-9965.EPI-18-0263 Published October 2018

Article Figures & Data

Table 1.

Selected characteristics [medians (interquartile range) or percent] for renal cell carcinoma case and control subjects in the CPS-II cohort

	Controls	Cases
Characteristics	(n = 87)	(n = 87)	P^{^a}
Age, y	70.4 (65.7–75.4)	70.8 (66.5–75.4)	Matched
Male (%)	64.4	64.4	Matched
Race
White	97.7	97.7	Matched
BMI^b (kg/m²)	25.1 (22.9–28.1)	26.5 (24.0–28.7)	0.10
Smoking status^b
Never	47.5	35.8	0.31
Former	50.0	61.7
Current	2.5	2.5
History of diabetes^b (%)	10.3	17.2	0.19
History of kidney failure^c (%)	0.0	1.2	1.00
Physical activity^b (MET-h/wk)	14.0 (7.0–24.5)	14.0 (7.0–24.9)	0.89
College graduate^c (%)	47.7	52.9	0.17
Intake/day^b
Total energy (kcal)	1,788 (1,488–2,147)	1,778 (1,437–2,082)	0.88
Dietary vitamin D (IU)	188 (148–283)	179 (128–292)	0.87
Dietary calcium (mg)	730 (583–1,112)	744 (563–1,071)	0.94
Alcohol (drinks)	0.10 (0–0.72)	0.10 (0–0.75)	0.98
Use of dietary supplements^b (%)
Vitamin D	17.7	6.9	0.09
Calcium	38.2	36.1	0.80
Family history of kidney cancer^c	2.3	0.0	0.50
Family history of any other cancer^b	65.5	58.6	0.35

↵^aThe χ² test or Fisher exact test (when cells have expected counts <5) for categorical variables and Wilcoxon test for continuous variables.
↵^bAssessed at the time closest to blood collection.
↵^cAssessed at baseline in 1982.

Table 2.

Selected characteristics [medians (interquartile range) or percent] by quartile of circulating DBP concentration in the CPS-II cohort

	Q1	Q2	Q3	Q4
Characteristics	(<272 μg/mL)	(272–<294 μg/mL)	(294–<334 μg/mL)	(≥334 μg/mL)	P^{^a}
Age, y	71.6 (66.1–75.9)	72.5 (68.3–76.0)	70.1 (65.4–74.9)	67.8 (64.0–73.8)	0.06
Male (%)	74.0	72.6	64.1	38.2	0.003
Race (%)
White	96.0	98.0	97.4	100.0	0.69
BMI^b (kg/m²)	27.3 (23.6–29.6)	24.8 (23.0–27.4)	25.1 (22.1–27.5)	25.4 (23.2–28.2)	0.09
Smoking status^b (%)
Never	37.0	42.2	36.8	53.1	0.52
Former	63.0	55.6	57.9	43.8
Current	0.0	2.2	5.3	3.1
History of diabetes^b (%)	22.0	13.7	12.8	2.9	0.10
History of kidney failure^c (%)	0	0	0	2.9	0.25
Physical activity^b (MET-h/wk)	14.0 (7.0–26.5)	14.0 (7.0–24.5)	14.0 (7.0–24.0)	13.9 (7.0–29.0)	0.89
College graduate^c (%)	62.0	51.0	38.5	45.5	0.77
Intake/day^b
Total energy (kcal)	1,881 (1,445–2,254)	1,842 (1,538–2,159)	1,719 (1,378–2,082)	1,628 (1,495–2,137)	0.56
Dietary vitamin D (IU)	178 (141–283)	183 (114–303)	167 (125–283)	188 (160–220)	0.85
Dietary calcium (mg)	738 (630–945)	786 (539–1,144)	671 (500–1,133)	742 (633–1,115)	0.81
Alcohol (drinks)	0.17 (0–0.87)	0.20 (0–1.13)	0.07 (0–0.37)	0.07 (0–0.60)	0.38
Use of dietary supplements^b (%)
Vitamin D	11.9	9.8	6.5	22.3	0.29
Calcium	36.6	25.6	42.9	48.3	0.21
Family history of kidney cancer^c (%)	0	0	2.6	2.9	0.42
Family history of any other cancer^b (%)	60.0	51.0	64.1	79.4	0.07

↵^aThe χ² test or Fisher exact test (when cells have expected counts <5) for categorical variables and Wilcoxon test for continuous variables.
↵^bAssessed at the time closest to blood collection.
↵^cAssessed at baseline in 1982.

Table 3.

Association between circulating DBP concentration and risk of renal cell carcinoma in the CPS-II cohort

↵^aConditioned on matching factors (age, sex, race, date of blood collection).
↵^bConditioned on matching factors (age, sex, race, date of blood collection); additionally adjusted for BMI.
↵^cConditioned on matching factors (age, sex, race, date of blood collection); additionally adjusted for BMI, supplemental vitamin D use, and family history of any cancer.
↵^dConditioned on matching factors (age, sex, race, date of blood collection); additionally adjusted for BMI, supplemental vitamin D use, family history of any cancer, and smoking status.