Occupational exposure to chlorinated solvents and risk of head and neck cancer in men: a population-based case-control study in France

Table 2 Association between head and neck cancer and exposure to chlorinated solvents

	PCE			TCE			MC			CF			CT			At least one of these five chlorinated solvents
Exposure	Co	Ca	OR^a [95%CI]	Co	Ca	OR^a [95%CI]	Co	Ca	OR^a [95%CI]	Co	Ca	OR^a [95%CI]	Co	Ca	OR^a [95%CI]	Co	Ca	OR^a [95%CI]
Never	2581	1635	1	1686	938	1	2432	1508	1	2619	1691	1	2622	1686	1	1645	930	1
Ever	89	70	1.04 [0.69 to 1.59]	989	770	0.93 [0.77 to 1.36]	238	197	0.91 [0.69 to 1.18]	51	14	0.58 [0.27 to 1.26]	48	19	0.60 [0.30 to 1.19]	1030	778	0.91 [0.75 to 1.10]
Duration^b
Short	41	31	1.05 [0.56 to 1.94]	289	215	0.86 [0.66 to 1.14]	93	88	0.96 [0.65 to 1.43]	21	7	0.76 [0.26 to 2.20]	25	10	0.56 [0.22 to 1.43]	291	213	0.87 [0.66 to1.14]
Intermediate	25	23	1.27 [0.60 to 2.74]	390	290	0.97 [0.76 to 1.24]	66	46	0.73 [0.44 to 1.22]	13	2	0.20 [0.03 to 1.34]	10	3	0.36 [0.06 to 2.00]	409	295	0.93 [0.73 to 1.19]
Long	23	16	0.83 [0.37 to 1.88]	310	265	0.95 [0.73 to 1.23]	79	63	0.97 [0.62 to 1.52]	17	5	0.69 [0.18 to 2.60]	13	6	0.87 [0.25 to 2.97]	330	270	0.93 [0.72 to 1.20]
p for trend			0.88			0.85			0.67			0.23			0.38			0.69
CEI
Low	44	36	1.15 [0.64 to 2.07]	497	391	0.95 [0.75 to 1.19]	114	107	1.03 [0.71 to 1.48]	25	5	0.56 [0.16 to 1.90]	24	7	0.44 [0.15 to 1.29]	518	397	0.95 [0.75 to 1.19]
Medium	34	20	0.65 [0.31 to 1.36]	397	313	0.95 [0.74 to 1.21]	100	63	0.65 [0.43 to 1.00]	26	9	0.60 [0.22 to 1.61]	24	12	0.74 [0.30 to 1.83]	408	291	0.85 [0.67 to 1.10]
High	11	14	1.81 [0.68 to 4.82]	95	66	0.82 [0.54 to 1.23]	24	27	1.42 [0.70 to 2.87]	26	9	0.60 [0.22 to 1.61]	24	12	0.74 [0.30 to 1.83]	104	90	0.94 [0.64 to 1.38]
p for trend			0.48			0.38			0.97			0.05			0.39			0.51

Abbreviations PCE perchloroethylene, TCE trichloroethylene, MC methylene chloride, CF chloroform, CT carbon tetrachloride, OR odds ratio, CI confidence interval, CEI cumulative exposure index, Ca cases, Co controls
^aOR adjusted for age at interview, residence area, alcohol consumption, smoking status, frequency and duration of smoking, exposure to asbestos
s^bCategories of duration of exposure to solvents were defined as follows: for PCE: short: < 5, intermediate: 5–15, long: > 15; for TCE and ‘at least one of these five chlorinated solvents’: short: <5, intermediate: 5–20, long: > 20; for MC and CT short: < 5, intermediate: 5 to 15, long: > 15; for CF short: < 10, intermediate: 10 to 20, long: > 20

ISSN: 1476-069X