Table 4.

Prediagnostic antibodies to JC virus (JCV) and colorectal adenomas, Washington County, MD, 1989–2006

	cases		controls
JCV serostatus	n	%	n	%	OR1	95% CI1	OR2	95% CI2
JCV-negative	65	52.9	60	48.8	1.00	reference	1.00	reference
JCV-positive	58	47.2	63	51.2	0.83	(0.57–1.22)	0.84	(0.56–1.27)
By number of adenomas:
One adenoma
JCV-negative	38	59.4	28	43.8	1.00	reference	1.00	reference
JCV-positive	26	40.6	36	56.3	0.52	(0.31–0.90)	0.74	(0.26–0.85)
Multiple adenomas
JCV-negative	27	45.8	32	56.2	1.00	reference	1.00	reference
JCV-positive	32	54.2	27	45.8	1.56	(0.85–2.85)	1.81	(0.88–3.74)
By size:
<0.55cm
JCV-negative	29	60.4	21	43.8	1.00	reference	1.00	reference
JCV-positive	19	39.8	27	56.3	0.43	(0.21–0.89)	0.44	(0.22–0.90)
>=0.55cm
JCV-negative	23	47.9	29	60.4	1.00	reference	1.00	reference
JCV-positive	25	52.1	19	39.6	1.67	(0.91–3.04)	1.65	(0.86–3.19)
By site:
Rectum
JCV-negative	12	46.2	9	34.6	1.00	reference	1.00	reference
JCV-positive	14	53.9	17	65.4	0.63	(0.28–1.41)	0.60	(0.25–1.42)
Distal3
JCV-negative	38	55.1	37	56.6	1.00	reference	1.00	reference
JCV-positive	51	44.9	32	46.4	0.93	(0.56–1.56)	0.85	(0.46–1.54)
Proximal4
JCV-negative	27	50.0	29	53.7	1.00	reference	1.00	reference
JCV-positive	27	50.0	25	46.3	1.20	(0.66–2.18)	1.21	(0.66–2.23)
By Histology:
Tubular
JCV-negative	40	54.8	34	46.6	1.00	reference	1.00	reference
JCV-positive	33	45.2	39	53.4	0.67	(0.39–1.13)	0.61	(0.36–1.04)
Tubulovillous & Villous
JCV-negative	24	50.0	24	50.0	1.00	reference	1.00	reference
JCV-positive	24	50.0	24	50.0	1.00	(0.57–1.76)	1.16	(0.58–2.35)

¹Cases and controls matched on age, sex, race, cohort, date of blood draw

²Cases and controls matched on age, sex, race, cohort, date of blood draw; conditional logistic regression model included baseline smoking status (current/former/never) and body mass index

³Distal includes the descending and sigmoid colon

⁴Proximal includes the cecum, ascending colon, hepatic flexure, transverse colon, and splenic flexure

⁵Not estimable