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BackgroundThe benefits of endoscopic testing for colorectal-cancer screening are uncertain. We evaluated the effect of screening with flexible sigmoidoscopy on colorectal-cancer incidence and mortality. MethodsFrom 1993 through 2001, we randomly assigned 154,900 men and women 55 to 74 years of age either to screening with flexible sigmoidoscopy, with a repeat screening at 3 or 5 years, or to usual care. Cases of colorectal cancer and deaths from the disease were ascertained. ResultsOf the 77,445 participants randomly assigned to screening (intervention group), 83.5% underwent baseline flexible sigmoidoscopy and 54.0% were screened at 3 or 5 years. The incidence of colorectal cancer after a median follow-up of 11.9 years was 11.9 cases per 10,000 person-years in the intervention group (1012 cases), as compared with 15.2 cases per 10,000 person-years in the usual-care group (1287 cases), which represents a 21% reduction (relative risk, 0.79; 95% confidence interval [CI], 0.72 to 0.85; P

Background Among randomized trials evaluating flexible sigmoidoscopy (FSG) for its effect on colorectal cancer mortality, only the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial screened its participants more than one time. We report outcomes from the PLCO screening FSG program and evaluate the increased yield produced by a second FSG.

The National Lung Screening Trial (NLST) is a randomized multicenter study comparing low-dose helical computed tomography (CT) with chest radiography in the screening of older current and former heavy smokers for early detection of lung cancer, which is the leading cause of cancer-related death in the United States. Five-year survival rates approach 70% with surgical resection of stage IA disease; however, more than 75% of individuals have incurable locally advanced or metastatic disease, the latter having a 5-year survival of less than 5%. It is plausible that treatment should be more effective and the likelihood of death decreased if asymptomatic lung cancer is detected through screening early enough in its preclinical phase. For these reasons, there is intense interest and intuitive appeal in lung cancer screening with low-dose CT. The use of survival as the determinant of screening effectiveness is, however, confounded by the well-described biases of lead time, length, and overdiagnosis. Despite previous attempts, no test has been shown to reduce lung cancer mortality, an endpoint that circumvents screening biases and provides a definitive measure of benefit when assessed in a randomized controlled trial that enables comparison of mortality rates between screened individuals and a control group that does not undergo the screening intervention of interest. The NLST is such a trial. The rationale for and design of the NLST are presented.

Background The 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. Methods A 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. Results Compliance 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 (Ptrend < .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 screendetected 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. Conclusions The 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.

Background & Aims The recommended timing of surveillance colonoscopy for individuals with adenomatous polyps is based on adenoma histology, size, and number. The burden and cost of surveillance colonoscopy are significant. The aim of this study was to examine the use of surveillance colonoscopy on a community-wide basis. Methods We retrospectively queried participants in the Prostate, Lung, Colorectal, and Ovarian Cancer screening trial in 9 US communities about use of surveillance colonoscopy. Subjects whose initial colonoscopy showed advanced adenoma (AA), nonadvanced adenoma (NAA), or no adenoma (NA) findings were included. Colonoscopy examinations were confirmed by reviewing colonoscopy reports. Results Of 3876 subjects selected for inquiry, 3627 (93.6%) responded. The cumulative probability of a surveillance colonoscopy within 5 years was 58.4% (n = 1342) in the AA group, 57.5% in those with ≥3 NAAs (n = 117), 46.7% in those with 1–2 NAAs (n = 905), and 26.5% (n = 1263) in subjects with NAs. Within 7 years, 33.2% of subjects with AAs received ≥2 surveillance examinations versus 26.9% for those with ≥3 NAAs, 18.2% for those with 1 or 2 NAAs, and 10.4% for those with NAs. Incomplete colonoscopy, family history of colorectal cancer, or interval adenomatous findings could explain only a minority of surveillance colonoscopy in low-risk subjects. Conclusions In community practice, there is substantial overuse of surveillance colonoscopy among low-risk subjects and underuse among subjects with AAs. Interventions to better align use of surveillance colonoscopy with risk for advanced lesions are needed.

The effect of screening with prostate-specific-antigen (PSA) testing and digital rectal examination on the rate of death from prostate cancer is unknown. This is the first report from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial on prostate-cancer mortality.From 1993 through 2001, we randomly assigned 76,693 men at 10 U.S. study centers to receive either annual screening (38,343 subjects) or usual care as the control (38,350 subjects). Men in the screening group were offered annual PSA testing for 6 years and digital rectal examination for 4 years. The subjects and health care providers received the results and decided on the type of follow-up evaluation. Usual care sometimes included screening, as some organizations have recommended. The numbers of all cancers and deaths and causes of death were ascertained.In the screening group, rates of compliance were 85% for PSA testing and 86% for digital rectal examination. Rates of screening in the control group increased from 40% in the first year to 52% in the sixth year for PSA testing and ranged from 41 to 46% for digital rectal examination. After 7 years of follow-up, the incidence of prostate cancer per 10,000 person-years was 116 (2820 cancers) in the screening group and 95 (2322 cancers) in the control group (rate ratio, 1.22; 95% confidence interval [CI], 1.16 to 1.29). The incidence of death per 10,000 person-years was 2.0 (50 deaths) in the screening group and 1.7 (44 deaths) in the control group (rate ratio, 1.13; 95% CI, 0.75 to 1.70). The data at 10 years were 67% complete and consistent with these overall findings.After 7 to 10 years of follow-up, the rate of death from prostate cancer was very low and did not differ significantly between the two study groups. (ClinicalTrials.gov number, NCT00002540.)

Surveillance colonoscopy is recommended for subjects with a history of adenomas but there is limited information on the yield of surveillance.A sample of subjects in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial with abnormal flexible sigmoidoscopy and follow-up colonoscopy were queried about subsequent surveillance colonoscopy over a 10-year period. Medical records were obtained to verify procedure dates and histologic findings. Subjects with advanced adenomas, nonadvanced adenoma, nonadenomatous polyps, and no polyps at baseline were included.At the first surveillance, 10.5% had advanced adenoma and 37% had any adenoma in the advanced adenoma group (n = 1057), compared with rates of 6.8% and 32% (nonadvanced adenoma: n = 765), 4.9% and 22% (nonadenomatous polyps: n = 658), and 3.1% and 16% (no polyps: n = 127) (P.0001, linear trend test). Mean (SD) time intervals (years) from baseline colonoscopy to first surveillance were 3.4 (2.0) for advanced adenoma, 4.3 (2.0) for nonadvanced adenoma, 4.5 (2.0) for nonadenomatous polyps, and 4.7 (2.0) for no polyps. There were no increasing (or decreasing) trends in the observed rate of advanced adenoma or any adenoma with time to the initial surveillance examination in any baseline group. Among subjects with a second surveillance examination, adenoma findings at both baseline and first surveillance influenced the rates of advanced adenoma and any adenoma at second surveillance.Subjects with baseline advanced adenomas are more likely to have recurrent advanced adenomas at initial surveillance. The lack of association between recurrence rates and time to surveillance suggests limitations in our understanding of the biology of adenoma development.

BACKGROUND: Research on the association between fruit and vegetable intake and risk of colorectal adenoma is inconclusive. OBJECTIVE: We studied whether intake of fruit, vegetables, or their subgroups is associated with a lower risk of prevalent colorectal adenoma. DESIGN: In men and women (aged 55-74 y) who were screened for colorectal cancer in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) (1993-2001), we compared 3057 cases with at least one prevalent histologically verified adenoma of the distal large bowel with 29 413 control subjects. Using a food-frequency questionnaire, we quantified intake of fruit and vegetables in the 12 mo before screening as energy-adjusted pyramid servings/d (ps/d). Adjusted odds ratios (ORs) and 95% CIs were estimated by logistic regression. RESULTS: Risk of distal adenoma was significantly lower among subjects in high ([almost equal to]5.7 ps/d) versus low ([almost equal to]1.2 ps/d) quintiles of total fruit intake (OR: 0.75; 95% CI: 0.66, 0.86, P for trend

Biomedical research cannot succeed without funding, knowledgeable staff, and appropriate infrastructure. There are however equally important but intangible factors that are rarely considered in planning large multidisciplinary endeavors or evaluating their success. The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial required extensive collaborations between individuals from many fields, including clinicians, clinical trialists, and administrators; it also addressed questions across the spectrum of cancer prevention and control. In this manuscript, we examine the experiences and opinions of trial staff regarding the building of successful relationships in PLCO. We summarize, in narrative form, data collected using open-ended questionnaires that were administered to the National Cancer Institute project officers, coordinating center staff, screening center principal investigators, and screening center coordinators in 2015, about 3 years after publication of the final primary trial manuscript. Trust, respect, listening to others, and in-person interaction were frequently mentioned as crucial to building successful relationships.

The prostate component of the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial was undertaken to determine whether there is a reduction in prostate cancer mortality from screening using serum prostate-specific antigen (PSA) testing and digital rectal examination (DRE). Mortality after 7-10 years of follow-up has been reported previously. We report extended follow-up to 13 years after the trial.A total of 76 685 men, aged 55-74 years, were enrolled at 10 screening centers between November 1993 and July 2001 and randomly assigned to the intervention (organized screening of annual PSA testing for 6 years and annual DRE for 4 years; 38 340 men) and control (usual care, which sometimes included opportunistic screening; 38 345 men) arms. Screening was completed in October 2006. All incident prostate cancers and deaths from prostate cancer through 13 years of follow-up or through December 31, 2009, were ascertained. Relative risks (RRs) were estimated as the ratio of observed rates in the intervention and control arms, and 95% confidence intervals (CIs) were calculated assuming a Poisson distribution for the number of events. Poisson regression modeling was used to examine the interactions with respect to prostate cancer mortality between trial arm and age, comorbidity status, and pretrial PSA testing. All statistical tests were two-sided.Approximately 92% of the study participants were followed to 10 years and 57% to 13 years. At 13 years, 4250 participants had been diagnosed with prostate cancer in the intervention arm compared with 3815 in the control arm. Cumulative incidence rates for prostate cancer in the intervention and control arms were 108.4 and 97.1 per 10 000 person-years, respectively, resulting in a relative increase of 12% in the intervention arm (RR = 1.12, 95% CI = 1.07 to 1.17). After 13 years of follow-up, the cumulative mortality rates from prostate cancer in the intervention and control arms were 3.7 and 3.4 deaths per 10 000 person-years, respectively, resulting in a non-statistically significant difference between the two arms (RR = 1.09, 95% CI = 0.87 to 1.36). No statistically significant interactions with respect to prostate cancer mortality were observed between trial arm and age (P(interaction) = .81), pretrial PSA testing (P(interaction) = .52), and comorbidity (P(interaction) = .68).After 13 years of follow-up, there was no evidence of a mortality benefit for organized annual screening in the PLCO trial compared with opportunistic screening, which forms part of usual care, and there was no apparent interaction with age, baseline comorbidity, or pretrial PSA testing.

Diagnosis of colorectal cancer after negative findings on endoscopic evaluation raises concern about the effectiveness of endoscopic screening. We contrast screening-detected cancers with cancers not detected by screening among participants assigned to flexible sigmoidoscopy (FSG) in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial to determine the reasons for the lack of detection of prevalent lesions.Cancers detected within 1 year of a screening FSG with abnormal findings were classified as screening detected. All other cancers were categorized, based on cancer stage and years until detection, as either not detectable or prevalent but not detected at the time of screening.A total of 77,447 subjects in the multicenter PLCO trial.A total of 977 colorectal cancers were diagnosed with a mean follow-up of 11.5 years.A total of 243 (24.9%) cancers were screening detected, 470 (48.1%) were not detectable at screening, and 264 (27.0%) were considered prevalent but not detected. Among prevalent nondetected lesions, 35.6% (n = 94) were attributed to problems in patient compliance (58 never screened, 34 delayed colonoscopy follow-up, and 2 inadequate bowel preparation), 43.9% (n = 116) were attributable to a limitation in the FSG procedure (97 beyond the reach of the sigmoidoscope and 19 inadequate depth of insertion on FSG), and 20.5% (n = 54) were caused by endoscopist limitation (33 missed on FSG, 21 missed at initial colonoscopy) (P.0001). Had colonoscopy instead of FSG been used for screening, an additional 15.6% and as many as 19.0% of cancers may have been screening-detected.These estimates are reasonable approximations, but biological variability precludes precise determinations.Prevalent nondetected cancers were more often attributable to problems with patient compliance or limitations in the FSG procedure than to missed lesions. Colonoscopy instead of FSG could have moderately increased the detection of cancer via screening.

OBJECTIVE To describe the results of the first four rounds (T0-T3) of prostate cancer screening in the Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial (designed to determine the value of screening in the four cancers), that for prostate cancer is evaluating whether annual screening with prostate-specific antigen (PSA) and a digital rectal examination (DRE) reduces prostate cancer-specific mortality. SUBJECTS AND METHODS In all, 38 349 men aged 55–74 years were randomized to undergo annual screening with PSA (abnormal >4.0 ng/mL) and a DRE. The follow-up of abnormal screening results was at the discretion of subjects’ physicians. PLCO staff obtained records related to diagnostic follow-up of positive screen results. RESULTS Compliance with screening decreased slightly from 89% at baseline to 85% at T3. Both PSA positivity rates (range 7.7–8.8% at T0-T3) and DRE positivity rates (range 6.8–7.6% at T0-T3) were relatively constant over time. The positive predictive value (PPV) of a PSA level of >4.0 ng/mL decreased from 17.9% at T0 to 10.4–12.3% at T1-T3; the PPV for DRE (in the absence of a positive PSA test) was constant over time (2.9–3.6%). Cancer was diagnosed in 1902 men (4.9%). Screen-detected cancers at T0 (549) were more likely to be clinical stage III/IV (5.8%) and to have a Gleason score of 7–10 (34%) than screen-detected cancers at T1-T3 (1.5–4.2% stage III/IV and 24–27% Gleason score 7–10 among 1054 cases). CONCLUSION The present findings on serial prostate screening are similar to those reported from other multi-round screening studies. Determining the effect of PSA screening on prostate cancer mortality awaits further follow-up.

Context The effect on mortality of screening for lung cancer with modern chest radiographs is unknown. Objective To evaluate the effect on mortality of screening for lung cancer using radiographs in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Design, Setting, and Participants Randomized controlled trial that involved 154 901 participants aged 55 through 74 years, 77 445 of whom were assigned to annual screenings and 77 456 to usual care at 1 of 10 screening centers across the United States between November 1993 and July 2001. The data from a subset of eligible participants for the National Lung Screening Trial (NLST), which compared chest radiograph with spiral computed tomographic (CT) screening, were analyzed. Intervention Participants in the intervention group were offered annual posteroanterior view chest radiograph for 4 years. Diagnostic follow-up of positive screening results was determined by participants and their health care practitioners. Participants in the usual care group were offered no interventions and received their usual medical care. All diagnosed cancers, deaths, and causes of death were ascertained through the earlier of 13 years of follow-up or until December 31, 2009. Main Outcome Measures Mortality from lung cancer. Secondary outcomes included lung cancer incidence, complications associated with diagnostic procedures, and all-cause mortality. Results Screening adherence was 86.6% at baseline and 79% to 84% at years 1 through 3; the rate of screening use in the usual care group was 11%. Cumulative lung cancer incidence rates through 13 years of follow-up were 20.1 per 10 000 person-years in the intervention group and 19.2 per 10 000 person-years in the usual care group (rate ratio [RR]; 1.05, 95% CI, 0.98-1.12). A total of 1213 lung cancer deaths were observed in the intervention group compared with 1230 in usual care group through 13 years (mortality RR, 0.99; 95% CI, 0.87-1.22). Stage and histology were similar between the 2 groups. The RR of mortality for the subset of participants eligible for the NLST, over the same 6-year follow-up period, was 0.94 (95% CI, 0.81-1.10). Conclusion Annual screening with chest radiograph did not reduce lung cancer mortality compared with usual care. Trial Registration clinicaltrials.gov Identifier: NCT00002540

Context Screening for ovarian cancer with cancer antigen 125 (CA-125) and transvaginal ultrasound has an unknown effect on mortality. Objective To evaluate the effect of screening for ovarian cancer on mortality in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. Design, Setting, and Participants Randomized controlled trial of 78 216 women aged 55 to 74 years assigned to undergo either annual screening (n = 39 105) or usual care (n = 39 111) at 10 screening centers across the United States between November 1993 and July 2001. Intervention The intervention group was offered annual screening with CA-125 for 6 years and transvaginal ultrasound for 4 years. Participants and their health care practitioners received the screening test results and managed evaluation of abnormal results. The usual care group was not offered annual screening with CA-125 for 6 years or transvaginal ultrasound but received their usual medical care. Participants were followed up for a maximum of 13 years (median [range], 12.4 years [10.9-13.0 years]) for cancer diagnoses and death until February 28, 2010. Main Outcome Measures Mortality from ovarian cancer, including primary peritoneal and fallopian tube cancers. Secondary outcomes included ovarian cancer incidence and complications associated with screening examinations and diagnostic procedures. Results Ovarian cancer was diagnosed in 212 women (5.7 per 10 000 person-years) in the intervention group and 176 (4.7 per 10 000 person-years) in the usual care group (rate ratio [RR], 1.21; 95% confidence interval [CI], 0.99-1.48). There were 118 deaths caused by ovarian cancer (3.1 per 10 000 person-years) in the intervention group and 100 deaths (2.6 per 10 000 person-years) in the usual care group (mortality RR, 1.18; 95% CI, 0.82-1.71). Of 3285 women with false-positive results, 1080 underwent surgical follow-up; of whom, 163 women experienced at least 1 serious complication (15%). There were 2924 deaths due to other causes (excluding ovarian, colorectal, and lung cancer) (76.6 per 10 000 person-years) in the intervention group and 2914 deaths (76.2 per 10 000 person-years) in the usual care group (RR, 1.01; 95% CI, 0.96-1.06). Conclusions Among women in the general US population, simultaneous screening with CA-125 and transvaginal ultrasound compared with usual care did not reduce ovarian cancer mortality. Diagnostic evaluation following a false-positive screening test result was associated with complications. Trial Registration clinicaltrials.gov Identifier: NCT00002540

Background & Aims: The efficacy of flexible sigmoidoscopy (FSG) in reducing colorectal cancer mortality is being evaluated in randomized trials. In 2 European trials, wide variability across examiners in FSG performance was noted. We report on the performance of examiners in the US randomized trial: the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Methods: Screening was performed at 10 geographically dispersed clinical centers. Patients with screens positive for a lesion or mass were referred to their private health care providers for endoscopic follow-up evaluation; lesions were not removed and a biopsy examination was not performed at screening. FSG performance among 64 examiners at these centers, each performing 100 or more baseline FSG examinations, with an aggregate of almost 50,000 examinations, was analyzed. Results: Screen-positivity results among examiners ranged from 9%–58%, with a coefficient of variation (CV) of 36%. CVs were 29% for distal polyp detection and 21% for distal adenoma detection. Inadequate rates ranged from 1%–27% (CV, 52%). Examiners with higher screen-positivity rates had higher false-positive rates, defined as a positive screen with no distal lesion found on endoscopic follow-up evaluation. Conclusions: Considerable variability exists in the rates of positive screens and in polyp and adenoma detection rates among FSG examiners performing the procedures using a common protocol.

The objectives of the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial are to determine in screenees ages 55-74 at entry whether screening with flexible sigmoidoscopy (60-cm sigmoidoscope) can reduce mortality from colorectal cancer, whether screening with chest X-ray can reduce mortality from lung cancer, whether screening men with digital rectal examination (DRE) plus serum prostate-specific antigen (PSA) can reduce mortality from prostate cancer, and whether screening women with CA125 and transvaginal ultrasound (TVU) can reduce mortality from ovarian cancer. Secondary objectives are to assess screening variables other than mortality for each of the interventions including sensitivity, specificity, and positive predictive value; to assess incidence, stage, and survival of cancer cases; and to investigate biologic and/or prognostic characterizations of tumor tissue and biochemical products as intermediate endpoints. The design is a multicenter, two-armed, randomized trial with 37,000 females and 37,000 males in each of the two arms. In the intervention arm, the PSA and CA125 tests are performed at entry, then annually for 5 years. The DRE, TVU, and chest X-ray exams are performed at entry and then annually for 3 years. Sigmoidoscopy is performed at entry and then at the 5-year point. Participants in the control arm follow their usual medical care practices. Participants will be followed for at least 13 years from randomization to ascertain all cancers of the prostate, lung, colorectum, and ovary, as well as deaths from all causes. A pilot phase was undertaken to assess the randomization, screening, and data collection procedures of the trial and to estimate design parameters such as compliance and contamination levels. This paper describes eligibility, consent, and other design features of the trial, randomization and screening procedures, and an outline of the follow-up procedures. Sample-size calculations are reported, and a data analysis plan is presented.