Table 1.

Baseline characteristics of colorectal cancer cases, colorectal adenoma cases and controls, Washington County, MD, 1975 to 2006

	Colorectal cancer (CRC)					Colorectal adenomas
	cases		controls			cases		controls
Characteristic	n	%	n	%	p-value	n	%	n	%	p-value
Cohort participation1
CLUE I only (1974)	354	57.9	354	57.9		0	0.0	0	0.0
CLUE II only (1989)	139	22.7	139	22.7		123	100.0	123	100.0
CLUE I and II	118	19.3	118	19.3	matched	0	0.0	0	0.0	matched
Age in years (mean +/-SD)1	56.2 +/− 12.4		56.2 +/− 12.3		matched	55.1 +/− 9.7		54.9 +/− 9.6		matched
Sex1
male	269	44.0	269	44.0		61	49.6	61	49.6
female	342	56.0	342	56.0	matched	62	50.4	62	50.4	matched
Race1
White	600	98.2	600	98.2		123	100.0	123	100.0
other	11	1.8	00	1.8	matched	0	0.0	0	0.0	matched
Smoking status
current	158	21.7	154	21.1		21	17.1	15	12.2
former	230	31.6	197	27.0		52	42.3	41	33.3
never	341	46.8	378	51.9	0.18	50	40.7	67	54.5	0.08
Body mass index (kg/m2)3
< 25	102	39.7	104	40.5		52	42.3	51	41.5
25–30	103	40.1	110	42.8		49	39.8	54	43.9
30+	52	20.2	43	16.7	0.51	22	17.9	18	14.6	0.71
NSAID use at baseline2
Yes	176	24.1	209	28.7		38	30.9	29	23.6
No	553	75.9	520	71.3	0.05	85	69.1	94	76.4	0.18
Family history of CRC3
no	124	78.0	150	86.7		86	71.7	98	83.8
yes	35	22.0	23	13.3	0.04	34	28.33	19	16.2	0.03
Recent hormone use3,4
none	178	87.7	185	89.4		49	81.7	42	67.7
any	25	12.3	22	10.6	0.64	11	18.3	20	32.3	0.10

¹matching factors

²non-steroidal anti-inflammatory drugs (NSAID) use within 48 hours prior to blood draw

³data obtained from CLUE II participants only

⁴data presented for females only