White blood cell DNA methylation and risk of breast cancer in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO).
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ABSTRACT:
SUBMITTER: Sturgeon SR
PROVIDER: S-EPMC5563066 | biostudies-other | 2017 Aug
REPOSITORIES: biostudies-other
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Project description:BackgroundWhite blood cell (WBC) DNA may contain methylation patterns that are associated with subsequent breast cancer risk. Using a high-throughput array and samples collected, on average, 1.3 years prior to diagnosis, a case-cohort analysis nested in the prospective Sister Study identified 250 individual CpG sites that were differentially methylated between breast cancer cases and noncases. We examined five of the top 40 CpG sites in a case-control study nested in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) Cohort.MethodsWe investigated the associations between prediagnostic WBC DNA methylation in 297 breast cancer cases and 297 frequency-matched controls. Two WBC DNA specimens from each participant were used: a proximate sample collected 1 to 2.9 years and a distant sample collected 4.2-7.3 years prior to diagnosis in cases or the comparable timepoints in controls. WBC DNA methylation level was measured using targeted bisulfite amplification sequencing. We used logistic regression to obtain ORs and 95% confidence intervals (CI).ResultsA one-unit increase in percent methylation in ERCC1 in proximate WBC DNA was associated with increased breast cancer risk (adjusted OR = 1.29; 95% CI, 1.06-1.57). However, a one-unit increase in percent methylation in ERCC1 in distant WBC DNA was inversely associated with breast cancer risk (adjusted OR = 0.83; 95% CI, 0.69-0.98). None of the other ORs met the threshold for statistical significance.ConclusionsThere was no convincing pattern between percent methylation in the five CpG sites and breast cancer risk.ImpactThe link between prediagnostic WBC DNA methylation marks and breast cancer, if any, is poorly understood.
| S-EPMC10825794 | biostudies-literature
Project description:BackgroundThe 5-year overall survival rate of lung cancer patients is approximately 15%. Most patients are diagnosed with advanced-stage disease and have shorter survival rates than patients with early-stage disease. Although screening for lung cancer has the potential to increase early diagnosis, it has not been shown to reduce lung cancer mortality rates. In 1993, the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial was initiated specifically to determine whether screening would reduce mortality rates from PLCO cancers.MethodsA total of 77 464 participants, aged 55-74 years, were randomly assigned to the intervention arm of the PLCO Cancer Screening Trial between November 8, 1993, and July 2, 2001. Participants received a baseline chest radiograph (CXR), followed by three annual single-view CXRs at the 10 US screening centers. Cancers were classified as screen detected and nonscreen detected (interval or never screened) and according to tumor histology. The positivity rates of screen-detected cancers and positive predictive values (PPVs) were calculated. Because 51.6% of the participants were current or former smokers, logistic regression analysis was performed to control for smoking status. All statistical tests were two-sided.ResultsCompliance with screening decreased from 86.6% at baseline to 78.9% at the last screening. Overall positivity rates were 8.9% at baseline and 6.6%-7.1% at subsequent screenings; positivity rates increased modestly with smoking risk categories (P(trend) < .001). The PPVs for all participants were 2.0% at baseline and 1.1%, 1.5%, and 2.4% at years 1, 2, and 3, respectively; PPVs in current smokers were 5.9% at baseline and 3.3%, 4.2%, and 5.6% at years 1, 2, and 3, respectively. A total of 564 lung cancers were diagnosed, of which 306 (54%) were screen-detected cancers and 87% were non-small cell lung cancers. Among non-small cell lung cancers, 59.6% of screen-detected cancers and 33.3% of interval cancers were early (I-II) stage.ConclusionsThe PLCO Cancer Screening Trial demonstrated the ability to recruit, retain, and screen a large population over multiple years at multiple centers. A higher proportion of screen-detected lung cancers were early stage, but a conclusion on the effectiveness of CXR screening must await final PLCO results, which are anticipated at the end of 2015.
| S-EPMC2873186 | biostudies-literature
Project description:BackgroundThe prostate component of the Prostate, Lung, Colorectal, and Ovarian (PLCO) randomized screening trial demonstrated no mortality effect of screening. Here we analyze prostate cancer specific survival in PLCO and its relation to screening.Methods76,693 men aged 55-74 were randomized to usual care (n = 38,350) or intervention (n = 38,343). Intervention arm men received annual prostate-specific antigen (6 years) and digital rectal exam (4 years). Men were followed for cancer diagnosis and mortality through 13 years. Medical record abstractors confirmed prostate cancer diagnoses, stage and grade. Prostate-specific survival in PLCO cases was analyzed using Kaplan-Meier analysis and proportional hazards modeling. We utilized data from the Surveillance, Epidemiology and End Results (SEER) program to compute expected survival in PLCO and compared this to observed.ResultsThere was no significant difference in prostate-specific survival rates between arms; 10 year survival rates were 94.7% (intervention, n = 4250 cases) versus 93.5% (usual care, n = 3815 cases). Within the intervention arm, cases never screened in PLCO had lower 10 year survival rates (82%) than screen detected or interval (following a negative screen) cases, both around 95.5%. The ratio of observed to expected 10 year prostate-specific death (1-survival) rates was 0.59 (95% CI: 0.51-0.68) for all PLCO cases, 0.66 (95% CI: 0.51-0.81) for Gleason 5-7 cases and 1.07 (95% CI: 0.87-1.3) for Gleason 8-10 cases.ConclusionProstate cancer specific survival in PLCO was comparable across arms and significantly better than expected based on nationwide population data. How much of the better survival is due to a healthy volunteer effect and to lead-time and overdiagnosis biases is not readily determinable.
| S-EPMC3582194 | biostudies-literature
Project description:IntroductionIdentification of individuals at high risk for lung cancer should be of value to individuals, patients, clinicians, and researchers. Existing prediction models have only modest capabilities to classify persons at risk accurately.MethodsProspective data from 70 962 control subjects in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) were used in models for the general population (model 1) and for a subcohort of ever-smokers (N = 38 254) (model 2). Both models included age, socioeconomic status (education), body mass index, family history of lung cancer, chronic obstructive pulmonary disease, recent chest x-ray, smoking status (never, former, or current), pack-years smoked, and smoking duration. Model 2 also included smoking quit-time (time in years since ever-smokers permanently quit smoking). External validation was performed with 44 223 PLCO intervention arm participants who completed a supplemental questionnaire and were subsequently followed. Known available risk factors were included in logistic regression models. Bootstrap optimism-corrected estimates of predictive performance were calculated (internal validation). Nonlinear relationships for age, pack-years smoked, smoking duration, and quit-time were modeled using restricted cubic splines. All reported P values are two-sided.ResultsDuring follow-up (median 9.2 years) of the control arm subjects, 1040 lung cancers occurred. During follow-up of the external validation sample (median 3.0 years), 213 lung cancers occurred. For models 1 and 2, bootstrap optimism-corrected receiver operator characteristic area under the curves were 0.857 and 0.805, and calibration slopes (model-predicted probabilities vs observed probabilities) were 0.987 and 0.979, respectively. In the external validation sample, models 1 and 2 had area under the curves of 0.841 and 0.784, respectively. These models had high discrimination in women, men, whites, and nonwhites.ConclusionThe PLCO lung cancer risk models demonstrate high discrimination and calibration.
| S-EPMC3131220 | biostudies-literature
Project description:BackgroundTwo recent metabolomic analyses found serum lipid, energy, and other metabolites related to aggressive prostate cancer risk up to 20 years prior to diagnosis.MethodsWe conducted a serum metabolomic investigation of prostate cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial that included annual serum total prostate-specific antigen measurement and digital rectal examination. This nested study included 380 cases diagnosed post-screening and 380 controls individually matched to cases on age, race, study centre, and blood-collection date (median time to diagnosis, 10 years (range 4.4-17 years)). Sera were analysed on a high-resolution accurate mass platform of ultrahigh-performance liquid and gas chromatography/mass spectroscopy that identified 695 known metabolites. Logistic regression conditioned on the matching factors estimated odds ratios (OR) and 95% confidence intervals of risk associated with an 80th percentile increase in the log-metabolite signal.ResultsTwenty-seven metabolites were associated with prostate cancer at P<0.05. Pyroglutamine, gamma-glutamylphenylalanine, phenylpyruvate, N-acetylcitrulline, and stearoylcarnitine showed the strongest metabolite-risk signals (ORs=0.53, 0.51, 0.46, 0.58, and 1.74, respectively; 0.001?P?0.006). Findings were similar for aggressive disease (peptide chemical class, P=0.03). None of the P-values were below the threshold of Bonferroni correction, however.ConclusionsA unique metabolomic profile associated with post-screening prostate cancer is identified that differs from that in a previously studied, unscreened population.
| S-EPMC5117796 | biostudies-literature
Project description:Non-steroidal anti-inflammatory drugs (NSAIDs) have been documented in animal and human studies to reduce risk for colorectal cancer and adenomatous polyps, but risk modification for subgroups of the population and effects on hyperplastic polyps have been less studied.Data on recent use of two frequently ingested NSAIDs, aspirin and ibuprofen, were collected at baseline from participants aged 55-74 years in the 10 centers of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO). Participants randomized to the intervention arm of the trial received a flexible sigmoidoscopy during a baseline examination. Follow-up of detected polyps was accomplished outside the Trial setting and relevant records were sought and abstracted. Cases (n=4,017) included subjects with a biopsy-proven polyp in the left side of the colon (descending colon, sigmoid, and rectum) detected as a consequence of PLCO screening; controls (n=38,396) were subjects with no left-sided colon polyp.Regular use of aspirin (≥ 4 times/month) in the past year was inversely associated with hyperplastic polyps (odds ratios (OR)=0.8, 95% confidence interval (CI)=0.7-0.9), adenomatous polyps (OR=0.8, 95% CI=0.8-0.9), and advanced adenomas (OR=0.8, 95% CI=0.7-0.9). As frequency of aspirin use increased, the prevalence of polyps decreased significantly for each histological classification (P for trend ≤ 0.0004). Similar patterns were found for adenomas and ibuprofen. Overall protection was consistent in both the descending colon or sigmoid and the rectum, but more evident in males. In males, the OR for heavy use of combined aspirin and ibuprofen (≥ 2 times/day) was 0.6 (95% CI=0.5-0.8), as opposed to 0.9 (95% CI=0.8-1.1) in females. The protective effects of NSAIDs for females were apparent only among those with body mass index (BMI) <25 (OR=0.8, 95% CI=0.7-1.0 for regular use of NSAIDs; P interaction=0.04). We also found a slightly stronger protection of NSAIDs in the 70-74 years age group compared with those aged 55-69 years.This study of a large general risk population supports previous work that recent use of aspirin and ibuprofen is associated with a decreased risk of colorectal adenomas and demonstrates that this protective effect may be stronger in certain population subgroups and is also evident for aspirin and hyperplastic polyps.
| S-EPMC5557093 | biostudies-other
Project description:Lung cancer is the major cause of cancer mortality. One of the aims of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) was to determine if annual screening chest radiographs reduce lung cancer mortality. We enrolled 154,900 individuals, aged 55-74 years; 77,445 were randomized to the intervention arm and received an annual chest radiograph for 3 or 4 years. Participants with a positive screen underwent diagnostic evaluation under guidance of their primary physician. Methods of diagnosis or exclusion of cancer, interval from screen to diagnosis, and factors predicting diagnostic testing were evaluated. One or more positive screens occurred in 17% of participants. Positive screens resulted in biopsy in 3%, with 54% positive for cancer. Biopsy likelihood was associated with a mass, smoking, age, and family history of lung cancer. Diagnostic testing stopped after a chest radiograph or computed tomography/magnetic resonance imaging in over half. After a second or subsequent positive screen, evaluation stopped after comparison to prior radiographs in over half. Of 308 screen-detected cancers, the diagnosis was established by thoracotomy/thoracoscopy in 47.7%, needle biopsy in 27.6%, bronchoscopy in 20.1% and mediastinoscopy in 2.9%. Eighty-four percent of screen-detected lung cancers were diagnosed within 6 months. Diagnostic evaluations following a positive screen were conducted in a timely fashion. Lung cancer was diagnosed by tissue biopsy or cytology in all cases. Lung cancer was excluded during evaluation of positive screening examinations by clinical or radiographic evaluation in all but 1.4% who required a tissue biopsy.
| S-EPMC3818308 | biostudies-literature
Project description:Red meat consumption has been positively associated with colorectal cancer; however, the biological mechanism underlying this relationship is not understood. Red meat is a major source of iron, which may play a role in colorectal carcinogenesis via increased crypt cell proliferation, cytotoxicity, and endogenous N-nitrosation. In a nested case-control study within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, we prospectively evaluated multiple iron exposure parameters, including dietary intake and serum measures of iron, ferritin, transferrin, total iron binding capacity (TIBC), and unsaturated iron binding capacity (UIBC) in relation to incident colorectal adenoma in 356 cases and 396 matched polyp-free controls. We also investigated variation in eight key genes involved in iron homeostasis in relation to colorectal adenoma in an additional series totaling 1,126 cases and 1,173 matched controls. We observed a positive association between red meat intake and colorectal adenoma [OR comparing extreme quartiles (OR(q4-q1)) = 1.59, 95% CI = 1.02-2.49, P(trend) = 0.03]. Serum TIBC and UIBC were inversely associated with colorectal adenoma (OR(q4-q1) = 0.57, 95% CI = 0.37-0.88, P(trend) = 0.03; and OR(q4-q1) = 0.62, 95% CI = 0.40-0.95, P(trend) = 0.04, respectively). Colorectal adenoma was not associated with serum ferritin, iron, or transferrin saturation or with polymorphisms in genes involved in iron homeostasis. Serum TIBC and UIBC, parameters that have a reciprocal relationship with overall iron load, were inversely related to colorectal adenoma, suggesting that individuals with lower iron status have a reduced risk of developing colorectal adenoma.
| S-EPMC3168068 | biostudies-literature
Project description:BackgroundThe impact of lung cancer screening on smoking behavior is unclear. The aims of this ancillary study of the Prostate Lung Colorectal and Ovarian Cancer Screening Trial were to produce risk prediction models to identify individuals at risk of relapse or continued smoking and to evaluate whether cancer-screening variables affect long-term smoking outcomes.MethodsParticipants completed a baseline questionnaire at trial enrollment and a supplemental questionnaire 4-14 years after enrollment, which assessed several cancer-related variables, including family history of cancer, comorbidities, and tobacco use. Multivariable logistic regression models were used to predict smoking status at completion of the supplemental questionnaire. The models' predictive performances were evaluated by assessing discrimination via the receiver operator characteristic area under the curve (ROC AUC) and calibration. Models were internally validated using bootstrap methods.ResultsOf the 31 694 former smokers on the baseline questionnaire, 1042 (3.3%) had relapsed (ie, reported being a current smoker on the supplemental questionnaire). Of the 6807 current smokers on the baseline questionnaire, 4439 (65.2%) reported continued smoking on the supplemental questionnaire. Relapse was associated with multiple demographic, medical, and tobacco-related characteristics. This model had a bootstrap median ROC AUC of 0.862 (95% confidence interval [CI] = 0.858 to 0.866) and a calibration slope of 1.004 (95% CI = 0.978 to 1.029), indicating excellent discrimination and calibration. Predictors of continued smoking also included multiple demographic, medical, and tobacco-related characteristics. This model had an ROC AUC of 0.611 (95% CI = 0.605 to 0.614) and a slope of 1.006 (95% CI = 0.962 to 1.041), indicating modest discrimination. Neither the trial arm nor the lung-screening result was statistically significantly associated with smoking outcomes.ConclusionThese models, if validated externally, may have public health utility in identifying individuals at risk for adverse smoking outcomes, who may benefit from relapse prevention and smoking cessation interventions.
| S-EPMC3490843 | biostudies-literature
Project description:BackgroundTo investigate the contribution of the dopamine transporter to dopaminergic reward-related behaviors and anthropometry, we evaluated associations between polymorphisms at the dopamine transporter gene(SLC6A3) and body mass index (BMI), among participants in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial.MethodsFour polymorphisms (rs6350, rs6413429, rs6347 and the 3' variable number of tandem repeat (3' VNTR) polymorphism) at the SLC6A3 gene were genotyped in 2,364 participants selected from the screening arm of PLCO randomly within strata of sex, age and smoking history. Height and weight at ages 20 and 50 years and baseline were assessed by questionnaire. BMI was calculated and categorized as underweight, normal, overweight and obese (<18.5, 18.5-24.9, 25.0-29.9, or > or = 30 kg/m2, respectively). Odds ratios (ORs) and 95% confidence intervals (CIs) of SLC6A3 genotypes and haplotypes were computed using conditional logistic regression.ResultsCompared with individuals having a normal BMI, obese individuals at the time of the baseline study questionnaire were less likely to possess the 3' VNTR variant allele with 9 copies of the repeated sequence in a dose-dependent model (** is referent; OR*9 = 0.80, OR99 = 0.47, Ptrend = 0.005). Compared with individuals having a normal BMI at age 50, overweight individuals (A-C-G-* is referent; ORA-C-G-9 = 0.80, 95% CI 0.65-0.99, p = 0.04) and obese individuals (A-C-G-* is referent; ORA-C-G-9 = 0.70, 95% CI 0.49-0.99, p = 0.04) were less likely to possess the haplotype with the 3'variant allele (A-C-G-9).ConclusionOur results support a role of genetic variation at the dopamine transporter gene, SLC6A3, as a modifier of BMI.
| S-EPMC2640369 | biostudies-literature