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.
View Article and Find Full Text PDFObjective: Heterocyclic amines (HAA) are animal carcinogens that are present in meat cooked at high temperature and in tobacco smoke. These compounds require activation by cytochrome P450 1A2 (CYP1A2) and N-acetyltransferase-2 (NAT2) before they can damage DNA. This study tested the hypotheses that well-done meat and cigarette smoking increase the risk of adenoma, the precursor to most colorectal cancers, especially in individuals with rapid CYP1A2 and rapid NAT2 activities.
View Article and Find Full Text PDFBackground: The 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.
Methods: From 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.
Background And Objective: 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.
Design: Cancers detected within 1 year of a screening FSG with abnormal findings were classified as screening detected.
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.
Methods: Participants were screened by 60-cm FSG in 10 regional screening centers at study entry and 3 or 5 years later, depending on the time of random assignment.
Background: 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.
View Article and Find Full Text PDFContext: 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.
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.
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.
View Article and Find Full Text PDFBackground & 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.
View Article and Find Full Text PDFBackground: 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.
Methods: From 1993 through 2001, we randomly assigned 76,693 men at 10 U.
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.
Clin Gastroenterol Hepatol
January 2009
Background & Aims: Surveillance colonoscopy is recommended for subjects with a history of adenomas but there is limited information on the yield of surveillance.
Methods: 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.
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 3,057 cases with at least one prevalent histologically verified adenoma of the distal large bowel with 29,413 control subjects.