Table 3.
Risk of pancreatic cancer according to quartiles of concentrations of persistent organic pollutants (POPs) in groups predefined as most valid of fasting (>6 h), diagnostic basis (microscopic confirmation) and weight (normal), and as most relevant (follow-up ≥10 years)a
| Persistent organic pollutants | Fasting >6 hb,c |
Microscopic confirmationb,d |
Normal weighte,f |
Follow-up ≥10 yearsb,g |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| OR | (95% CI) | P h | OR | (95% CI) | P h | OR | (95% CI) | P h | OR | (95% CI) | P h | |
| p, p′-DDT | ||||||||||||
| 1st quartile | 1.00 | 0.204 | 1.00 | 0.074 | 1.00 | 0.180 | 1.00 | 0.026 | ||||
| 2nd quartile | 1.06 | (0.55–2.03) | 1.15 | (0.80–1.67) | 1.45 | (0.91–2.32) | 1.22 | (0.70–2.14) | ||||
| 3rd quartile | 1.81 | (0.93–3.53) | 1.57 | (1.06–2.33) | 1.57 | (0.94–2.61) | 1.94 | (1.10–3.42) | ||||
| 4th quartile | 1.23 | (0.52–2.91) | 1.04 | (0.62–1.73) | 0.98 | (0.46–2.11) | 0.93 | (0.44–1.99) | ||||
| p, p’-DDE | ||||||||||||
| 1st quartile | 1.00 | 0.012i | 1.00 | 0.177i | 1.00 | 0.012i | 1.00 | 0.088i | ||||
| 2nd quartile | 0.98 | (0.46–2.07) | 1.05 | (0.73–1.51) | 1.32 | (0.81–2.14) | 1.23 | (0.70–2.15) | ||||
| 3rd quartile | 1.85 | (0.94–3.63) | 1.22 | (0.84–1.79) | 2.04 | (1.23–3.39) | 1.44 | (0.81–2.56) | ||||
| 4th quartile | 2.23 | (1.02–4.88) | 1.31 | (0.84–2.03) | 1.79 | (0.95–3.37) | 1.71 | (0.90–3.26) | ||||
| Oxychlordane | ||||||||||||
| 1st quartile | 1.00 | 0.072 | 1.00 | 0.192 | 1.00 | 0.111i | 1.00 | 0.242 | ||||
| 2nd quartile | 1.51 | (0.77–2.94) | 1.37 | (0.94–1.99) | 1.04 | (0.63–1.74) | 1.52 | (0.84–2.73) | ||||
| 3rd quartile | 0.88 | (0.41–1.87) | 1.14 | (0.76–1.71) | 1.31 | (0.76–2.24) | 1.81 | (0.99–3.31) | ||||
| 4th quartile | 1.78 | (0.84–3.81) | 1.50 | (0.97–2.31) | 1.58 | (0.85–2.94) | 1.34 | (0.69–2.63) | ||||
| Trans-nonachlor | ||||||||||||
| 1st quartile | 1.00 | 0.058i | 1.00 | 0.032i | 1.00 | 0.041i | 1.00 | 0.026i | ||||
| 2nd quartile | 1.12 | (0.54–2.30) | 1.39 | (0.93–2.08) | 1.45 | (0.86–2.46) | 1.61 | (0.84–3.09) | ||||
| 3rd quartile | 1.16 | (0.55–2.47) | 1.30 | (0.85–1.99) | 1.81 | (1.05–3.11) | 2.49 | (1.28–4.85) | ||||
| 4th quartile | 1.93 | (0.90–4.14) | 1.74 | (1.11–2.73) | 1.81 | (0.97–3.37) | 2.19 | (1.06–4.51) | ||||
| β-hexachlorocyclohexane | ||||||||||||
| 1st quartile | 1.00 | 0.573 | 1.00 | 0.024 | 1.00 | 0.049 | 1.00 | 0.225 | ||||
| 2nd quartile | 0.74 | (0.37–1.45) | 0.73 | (0.50–1.06) | 0.68 | (0.40–1.16) | 0.78 | (0.43–1.41) | ||||
| 3rd quartile | 0.88 | (0.39–1.97) | 1.34 | (0.86–2.07) | 1.40 | (0.78–2.54) | 1.48 | (0.77–2.84) | ||||
| 4th quartile | 1.32 | (0.46–3.76) | 1.31 | (0.74–2.33) | 1.42 | (0.64–3.16) | 1.32 | (0.55–3.16) | ||||
| PCB 99 | ||||||||||||
| 1st quartile | 1.00 | 0.071 | 1.00 | 0.223 | 1.00 | 0.007i | 1.00 | 0.008i | ||||
| 2nd quartile | 0.71 | (0.34–1.46) | 0.75 | (0.50–1.11) | 1.05 | (0.62–1.80) | 1.14 | (0.61–2.14) | ||||
| 3rd quartile | 1.15 | (0.57–2.31) | 1.05 | (0.72–1.53) | 1.45 | (0.86–2.44) | 2.20 | (1.19–4.07) | ||||
| 4th quartile | 1.62 | (0.80–3.30) | 1.04 | (0.69–1.56) | 2.01 | (1.14–3.54) | 2.04 | (1.06–3.94) | ||||
| PCB 138 | ||||||||||||
| 1st quartile | 1.00 | 0.319 | 1.00 | 0.749 | 1.00 | 0.035i | 1.00 | 0.024i | ||||
| 2nd quartile | 0.87 | (0.41–1.82) | 0.95 | (0.63–1.43) | 1.97 | (1.13–3.41) | 1.30 | (0.65–2.61) | ||||
| 3rd quartile | 1.20 | (0.56–2.59) | 0.96 | (0.63–1.47) | 1.64 | (0.90–3.00) | 1.85 | (0.90–3.79) | ||||
| 4th quartile | 1.56 | (0.70–3.44) | 1.13 | (0.73–1.76) | 2.32 | (1.23–4.36) | 2.13 | (1.01–4.51) | ||||
| PCB 183 | ||||||||||||
| 1st quartile | 1.00 | 0.072i | 1.00 | 0.369i | 1.00 | 0.027i | 1.00 | 0.023i | ||||
| 2nd quartile | 1.38 | (0.57–3.33) | 1.10 | (0.74–1.64) | 1.55 | (0.90–2.65) | 2.21 | (1.15–4.25) | ||||
| 3rd quartile | 1.41 | (0.59–3.38) | 1.15 | (0.76–1.75) | 1.57 | (0.90–2.73) | 2.46 | (1.20–5.05) | ||||
| 4th quartile | 2.12 | (0.86–5.21) | 1.22 | (0.79–1.90) | 2.10 | (1.14–3.88) | 2.76 | (1.31–5.80) | ||||
| Sum of orders, 16 POPs | ||||||||||||
| 1st quartile | 1.00 | 0.080i | 1.00 | 0.053 | 1.00 | 0.047i | 1.00 | 0.016i | ||||
| 2nd quartile | 1.77 | (0.79–3.97) | 1.41 | (0.95–2.10) | 1.57 | (0.92–2.67) | 2.41 | (1.20–4.83) | ||||
| 3rd quartile | 2.17 | (0.98–4.78) | 1.80 | (1.18–2.73) | 1.75 | (1.03–3.00) | 3.02 | (1.45–6.29) | ||||
| 4th quartile | 2.19 | (0.97–4.92) | 1.42 | (0.92–2.20) | 1.83 | (1.00–3.35) | 3.00 | (1.39–6.46) | ||||
| Sum of orders, 6 OC pesticides | ||||||||||||
| 1st quartile | 1.00 | 0.211i | 1.00 | 0.047i | 1.00 | 0.014i | 1.00 | 0.149i | ||||
| 2nd quartile | 1.19 | (0.61–2.32) | 1.07 | (0.73–1.56) | 1.41 | (0.87–2.27) | 1.45 | (0.81–2.60) | ||||
| 3rd quartile | 1.75 | (0.85–3.58) | 1.53 | (1.00–2.35) | 1.71 | (0.97–3.04) | 1.88 | (0.97–3.66) | ||||
| 4th quartile | 1.56 | (0.71–3.41) | 1.46 | (0.92–2.31) | 2.22 | (1.15–4.26) | 1.71 | (0.84–3.46) | ||||
| Number of POPs at high concentrations (nPhc) | ||||||||||||
| 0 | 1.00 | 0.048i | 1.00 | 0.181i | 1.00 | 0.050i | 1.00 | 0.061 | ||||
| 1–5 | 1.78 | (0.95–3.35) | 1.13 | (0.80–1.61) | 1.64 | (1.05–2.55) | 1.78 | (1.09–2.93) | ||||
| >5 | 2.01 | (1.05–3.84) | 1.28 | (0.89–1.84) | 1.61 | (0.97–2.69) | 1.71 | (0.99–2.97) | ||||
OR, odds ratio, an OR = 1 indicates the reference category; CI, onfidence interval; p, p’-DDT, dichlorodiphenyltrichloroethane; p, p’-DDE, dichlorodiphenyldichloroethene.
All four models are based on crude concentrations of persistent organic pollutants (POPs). Columns show results for the predefined1 most valid stratum of three variables: fasting (>6 h), diagnostic basis (microscopic confirmation) and normal weight, and for the most relevant stratum of the interval between blood extraction and date of cancer diagnosis of the index case (index date) (follow-up ≥10 years). Results for the most valid stratum of smoking (never smokers) are shown in Figure 1.
Conditional logistic regression, model further adjusted for body mass index.
n = 430 (150 cases and 280 controls).
n = 1110 (372 cases and 738 controls).
Since the model is restricted to a stratum (normal weight) of a non-matching factor (body mass index), ORs and CIs were calculated by unconditional logistic regression adjusting for all matching factors.
n = 611 (197 cases and 414 controls).
n = 532 (179 cases and 353 controls).
Unless otherwise specified, P-value derived from Wald’s test.
Test for linear trend (multivariate analogue of Mantel’s extension test).