Adipose tissue PCB levels and <i>CYP1B1</i> and <i>COMT</i> genotypes in relation to breast cancer risk in postmenopausal Danish women

<div><p>Exposure to PCBs may be an etiologic factor for breast cancer. The cytochrome P450 1B1 (<i>CYP1B1</i>) and catechol-<i>O</i>-methyltransferase (<i>COMT</i>) enzymes are involved in estrogen metabolism and PCB metabolism, both of which may relate to breast cancer susceptibility. Polymorphisms in genes regulating these enzymes control efficiency. Our objective was to assess whether <i>CYP1B1</i> and <i>COMT</i> gene polymorphisms modulate the effect of PCBs in breast cancer risk, among postmenopausal Danish women. Neither <i>CYP1B1 Leu432Val</i> polymorphisms nor adipose tissue PCBs were independently associated with breast cancer risk. When assessing the independent effect of the <i>COMT Val158Met</i> polymorphism, we observed reduced risk for breast cancer amongst hormone replacement therapy using women who were homozygous carriers of the variant allele compared with those carrying the wild-type variant (RR = 0.41; 95% CI: 0.29–0.89). We found no statistically significant interactions between any of the PCB groups and <i>CYP1B1</i> or <i>COMT</i> polymorphisms on the risk of breast cancer.</p></div

Results of adjusted^a space-time cluster analyses performed in SpaceStat, based on 15 nearest neighbours, 999 permutations, and by three different time scales.

a<p>Adjusted for previous history of autoimmune disease, HIV/AIDS or organ transplantation.</p>b<p>The total number of statistically significant cases with a <i>Q_ik</i> p-value of 0.001, which indicates the number of cases that are centers of clusters over their life-course. ^c Number of statistically significant <i>Q_ik</i> (p  =  0.001) cases that also have significant <i>Q_ikt</i> (p ≤ 0.05) and are members of a cluster of at least 4 cases. ^d Indicate where and when the cases tend to cluster.</p>e<p>Refers to the map in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0060800#pone-0060800-g002" target="_blank">figure 2</a>, which shows the suggested clusters of NHL in Denmark based on the adjusted analyses. ^f Control group.</p

Characteristics of Study Population.

<p>Testicular cancer cases diagnosed 1991–2003, and age-matched controls.</p

Results of analyses performed in SaTScan at selected time slices that match the time periods with the most significant space-time clusters found by Q-statistics.

a<p>Indicates at which point in time we decided to apply the methods of SaTScan. ^b Indicates the most significant clusters detected by SaTScan. ^c Number of cases that comprise the most significant clusters detected by SaTScan. ^d Name of the area where SaTScan identified the cluster. ^e Refers to the areas shown on the map in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0060800#pone-0060800-g003" target="_blank">figure 3</a>. ^f Control group.</p

Map of space-time clusters of non-Hodgkin lymphoma in Denmark adjusted for potential confounding factors.

<p>Three areas showing statistically significant clustering of non-Hodgkin lymphoma cases in Denmark identified with Q-statistics, based on 15 nearest neighbours and adjusted analyses. The circles indicate the extent of the clusters, not the number of cases comprising each cluster. None of these cluster regions were consistently found with both control groups.</p

Map of space-only clusters of non-Hodgkin lymphoma in Denmark.

<p>One area showing statistically significant clustering of non-Hodgkin lymphoma cases (area no. 8), and two areas showing borderline clustering (area no. 9 and 10), based on spatial scan statistics of SaTScan and a maximum cluster size of 10% of the total population, using year when clusters were suggested by Q-statistics. None of these cluster regions were consistently found with both control groups.</p

Adjusted Analysis.

<p>Results of the cluster analysis of testicular cancer in Denmark, adjusted for family history of testicular cancer, following the same format as used in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0120285#pone.0120285.t002" target="_blank">Table 2</a>.</p><p>Adjusted Analysis.</p

Map of space-time clusters of non-Hodgkin lymphoma in Denmark.

<p>Four areas showing statistically significant clustering of non-Hodgkin lymphoma cases in Denmark identified with Q-statistics, based on 15 nearest neighbours and unadjusted analyses. The circles indicate the extent of the clusters, not the number of cases comprising each cluster. None of these cluster regions were consistently found with both control groups.</p

Results of unadjusted space-time cluster analyses performed in SpaceStat, based on 15 nearest neighbours, 999 permutations, and by three different time scales.

a<p>The total number of statistically significant cases with a <i>Q_ik</i> p-value of 0.001, which indicates the number of cases that are centers of clusters over their life-course. ^b Number of statistically significant <i>Q_ik</i> (p  =  0.001) cases that also have significant <i>Q_ikt</i> (p ≤ 0.05) and are members of a cluster of at least 4 cases. ^c Indicate where and when the cases tend to cluster.</p>d<p>Refers to the map in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0060800#pone-0060800-g001" target="_blank">figure 1</a>, which shows the suggested clusters of NHL in Denmark based on the unadjusted analyses. ^e Control group.</p

Residential road traffic noise exposure and colorectal cancer survival – A Danish cohort study

<div><p>Background</p><p>Residential traffic noise exposure may entail sleep disruption and compromised circadian functioning; two factors which have been associated with a poor colorectal cancer (CRC) prognosis. Hence, the aim of the present study was to investigate the association between residential road traffic noise and CRC survival.</p><p>Methods and materials</p><p>Road traffic noise was calculated for all residential addresses from 1987 to February 2012 for incident CRC cases (n = 1,234) in a cohort of 57,053 Danes. We used Cox Proportional Hazard Models to investigate the association between residential road traffic noise at different time-windows, and overall and CRC-specific mortality. Furthermore, we investigated interaction with sex, age, prognostic factors, and comorbidity. Mortality Rate Ratios (MRR) were calculated in unadjusted models, and adjusted for railway noise, lifestyle factors, and socioeconomic variables.</p><p>Results</p><p>During a median follow-up of 4 years, 594 patients died; 447 from CRC. We found no association between road traffic noise exposure and overall (MRR 1.00 (0.88–1.13) per 10 dB) or CRC-specific mortality (MRR 0.98 (0.85–1.13) per 10 dB) over the entire follow-up period, or 1 year preceding death. Results did not differ when examining colon and rectal cancer separately. Interaction analyses suggested that patients with less clinically advanced disease could be more susceptible to harmful effects of traffic noise.</p><p>Conclusion</p><p>The present study suggests no overall association between residential road traffic noise and concurrent mortality in CRC patients. As it is the first study of its kind, with relatively limited power, further studies are warranted.</p></div