Lung cancer risk and pollution in an industrial region of Northern Spain: a hospital-based case-control study

Table 2 Odds ratios of lung cancer by histologic type and distribution of potential confounding variables

	Total				Squamous cell carcinoma			Adenocarcinoma			Small cell carcinoma
	Controls	Cases	OR (95%CI)^a	P-value	Cases	OR (95%CI)^a	P-value	Cases	OR (95%CI)^a	P-value	Cases	OR (95%CI)^a	P-value
	N	N			N			N			N
Smoking
Never	182	47	Reference		7	Reference		21	Reference		6	Reference
Former < 38 PY	151	62	2.84 (1.71-4.74)		22	7.63 (2.75-21.16)		14	1.63 (0.78-3.40)		6	2.34 (0.77-7.09)
Current < 38 PY	70	72	5.29 (3.14-8.91)		23	11.65 (4.10-33.06)		24	3.71 (1.85-7.44)		7	5.46 (1.91-15.57)
Former ≥ 38 PY	102	117	13.00 (7.63-22.15)		53	36.63 (13.14-102.13)		28	7.64 (3.65-16.03)		16	12.88 (4.38-37.87)
Current ≥ 38 PY	109	320	23.74 (14.48-38.94)	<0.001^b	111	57.78 (21.46-155.58)	<0.001^b	69	12.12 (6.25-23.52)	<0.001^b	54	28.15 (10.65-74.39)	<0.001^b
Family history of cancer
None	371	338	Reference		108	Reference		90	Reference		57	Reference
Other cancers	204	190	1.02 (0.77-1.36)	0.607	77	1.46 (0.99-2.15)	0.161	48	0.86 (0.57-1.30)	0.885	21	0.67 (0.39-1.16)	0.319
Lung cancer	45	73	1.59 (1.00-2.51)	0.083	25	2.52 (1.38-4.61)	0.035	16	1.38 (0.72-2.66)	0.080	9	1.33 (0.59-3.01)	0.430
Occupation
Never	245	220	Reference		68	Reference		76	Reference		47	Reference
< 35 years	274	257	1.09 (0.79-1.49)		112	1.36 (0.88-2.10)		61	0.97 (0.61-1.54)		42	0.76 (0.44-1.31)
≥ 35 years	102	140	1.42 (0.96-2.10)	0.082^b	60	1.74 (1.04-2.92)	0.048^b	43	1.63 (0.94-2.82)	0.089^b	17	0.75 (0.37-1.53)	0.384^b

^aORs were estimated from a multiple logistic regression model that included age, sex, hospital area, tobacco consumption, family history of cancer, occupation, and exposure area
^bTest for trend

ISSN: 1476-072X