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Numerous organizations, including the United States Preventive Services Task Force, recommend annual lung cancer screening (LCS) with low-dose CT for high risk adults who meet specific criteria. Despite recommendations and national coverage for screening eligible adults through the Centers for Medicare and Medicaid Services, LCS uptake in the United States remains low (<4%). In recognition of the need to improve and understand LCS across the population, as part of the larger Population-based Research to Optimize the Screening PRocess (PROSPR) consortium, the NCI (Bethesda, MD) funded the Lung PROSPR Research Consortium consisting of five diverse healthcare systems in Colorado, Hawaii, Michigan, Pennsylvania, and Wisconsin. Using various methods and data sources, the center aims to examine utilization and outcomes of LCS across diverse populations, and assess how variations in the implementation of LCS programs shape outcomes across the screening process. This commentary presents the PROSPR LCS process model, which outlines the interrelated steps needed to complete the screening process from risk assessment to treatment. In addition to guiding planned projects within the Lung PROSPR Research Consortium, this model provides insights on the complex steps needed to implement, evaluate, and improve LCS outcomes in community practice., (©2019 American Association for Cancer Research.)

Purposes: Despite recommendations against prostate cancer screening with prostate-specific antigen (PSA) tests, about one-fourth of men age ≥40 years received PSA tests in 2015. This study aimed to answer 3 questions for men who had a PSA test in the past year: (1) What percentage of these men received the test first suggested by physicians? (2) What factors were associated with physician-initiated PSA testing (PIPT) versus patient/someone else-initiated testing? (3) What percentage of patients ever had shared decision-making when tests were initiated by physicians?, Methods: We analyzed the 2000 and 2015 National Health Interview Survey data. We calculated age-standardized prevalence of PIPT for both years. For 2015, we used logistic regression to calculate adjusted prevalence ratios for PIPT. We also calculated the prevalence of ever discussing both advantages and disadvantages., Results: The age-standardized prevalence of PIPT was significantly higher in 2015 (84.9%) than in 2000 (72.3%). In 2015, nearly 90% of PSA screenings for men aged ≥70 years were suggested by physicians. PIPT was positively associated with 2 or more comorbid conditions and number of patient visits to the doctor. Less than one-third of men reported they had ever participated in a discussion of advantages and disadvantages of PSA testing., Conclusions: The majority of men who had PSA testing in the past year reported that their physicians were the first to suggest testing, including men aged ≥70 years. Our study also points to the challenges and needs in conducting shared decision-making before PSA testing in clinical practice., Competing Interests: Conflict of interest: none declared., (© Copyright 2018 by the American Board of Family Medicine.)

Introduction: Recommendations for prostate-specific antigen-based screening for prostate cancer are placing increasing emphasis on men aged 55-69 years. The goal of the current study is to describe patterns of population-based prostate-specific antigen testing with details about that age group., Methods: National Health Interview Surveys from 2005 to 2015 were analyzed in 2017 to estimate routine prostate-specific antigen testing in the past year from self-reported data by age group (40-54, 55-69, ≥70 years), and also by risk group, defined as African American men or men with a family history of prostate cancer versus other men. Differences between successive survey years by age and risk groups were assessed by predicted margins and rate ratios with 99% CIs, using logistic regressions., Results: Prostate-specific antigen testing among men aged 55-69 years decreased from a high of 43.1% (95% CI=40.3, 46.1) in 2008 to a low of 32.8% (95% CI=30.8, 34.7) in 2013, with no significant change in 2015 at 33.8% (95% CI=31.3, 36.4). Men aged ≥70 years had consistently high prevalence in all survey years, ranging from 51.1% in 2008 to 36.4% in 2015. African American men, men with a family history of prostate cancer, and other men showed a 5% absolute decrease over time, but this reduction was significant only in other men., Conclusions: Despite decreases, the absolute change in prostate-specific antigen testing for men aged 55-69 years was small (9.3%) over the study period. Men aged ≥70 years, for whom the benefits are unlikely to exceed the harms, continue to have consistently high testing prevalence., (Published by Elsevier Inc.)

Objective: To obtain information from participants in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial regarding their perception of the retention materials employed by the screening centers. Also, to determine the viability of using email or the internet as a data collection tool with an older population., Design: Three of ten PLCO screening centers queried participants towards the end of the study (2010) as to their opinions of the various retention materials and whether they would have been willing to use electronic communication for study activities, had the option been available., Setting: The questionnaires were administered by mail, and responses were returned to the originating screening center., Participants: The participants in this study consisted of all the active participants at three PLCO screening centers: the University of Colorado Anschutz Medical Campus, the University of Utah, and Henry Ford Health System., Methods: A short, self-administered questionnaire was mailed to all active participants at three PLCO centers (n=41,482). This was a one-time mailing with no follow-up, as the responses were designed to be anonymous in order to obtain the most honest responses., Results: The response rate was 62%. Of respondents, 97% reported their PLCO experience was good or excellent. Nearly 50% of respondents indicated that receipt of an annual newsletter made them more likely to participate; newsletter features they reported as most important were those that conveyed information on cancer, study findings, and how their data were being used. Results did not support study coordinators' suppositions that receipt of a token gift or birthday card by participants was important for retention. Fewer than 30% of respondents indicated that they would have been unwilling to use a secure website to complete study forms., Conclusion: These data indicate the importance of querying participants rather than relying on impressions of study staff, and also indicate that the internet will be a viable means of data collection in future prevention studies that include older Americans., (© 2015 Marshfield Clinic.)

The aim of cancer screening is to detect asymptomatic cancers whose treatment will result in extension of life, relative to length of life absent screening. Unfortunately, cancer screening also results in overdiagnosis, the detection of cancers that, in the absence of screening, would not present symptomatically during one's lifetime. Thus, their detection and subsequent treatment is unnecessary and detrimental. This definition of overdiagnosis, while succinct, does not capture the ways it can occur, and our interactions with patients, advocates, researchers, clinicians, and journalists have led us to believe that the concept of overdiagnosis is difficult to explain and, for some, difficult to accept. We propose a dichotomy, the "tumor-patient" classification, to aid in understanding overdiagnosis. The tumor category includes asymptomatic malignant disease that would regress spontaneously if left alone, as well as asymptomatic malignant disease that stagnates or progresses too slowly to be life threatening in even the longest of lifetimes. The patient category includes asymptomatic malignant disease that would progress quickly enough to be life threatening during a lifetime of typical length, but lacks clinical relevance because death due to another cause intercedes prior to what would have been the date of symptomatic diagnosis had screening not occurred. Cancer screening of most organs is likely to result in overdiagnosis of both types. However, the ratio of tumor- to patient-driven overdiagnosis almost certainly varies, and may vary drastically, by organ, screening modality, patient characteristics, and other factors., (© Published by Oxford University Press 2015.)

Objective: Identify predictors of non-compliance with first round screening exams in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial., Method: The PLCO was conducted from 1993 to 2011 at 10 US institutions. A total of 154,897 healthy men and women ages 55-74 years were randomized. Intervention arm participants were invited to receive gender-appropriate screening exams for prostate, lung, colorectal and ovarian cancer. Using intervention-arm data (73,036 participants), non-compliance percentages for 13 covariates were calculated, as were unadjusted and adjusted odds ratios (ORs), and 95% confidence intervals. Covariates included demographic factors as well as factors specific to PLCO (e.g., method of consent, distance from screening center)., Results: The rate of non-compliance was 11% overall but varied by screening center. Significant associations were observed for most covariates but indicated modest increases or decreases in odds. An exception was the use of a two-step consent process (consented intervention arm participants for exams after randomization) relative to a one-step process (consented all participants prior to randomization) (OR: 2.2, 95% CI: 2.0-2.5). Non-compliance percentages increased with further distance from screening centers, but ORs were not significantly different from 1., Conclusions: Many factors modestly influenced compliance. Consent process was the strongest predictor of compliance., (Published by Elsevier Inc.)

Hispanics are underrepresented in medical research. At the National Lung Screening Trial's University of Colorado Denver screening center, traditional recruitment methods resulted in enrollment of few Hispanics. In response, the center adopted culturally sensitive recruitment techniques, including use of carefully-crafted bilingual materials. Bilingual interviewers were hired, and persons familiar with culture and language of groups of different Hispanic origin were consulted. Representation of Hispanics among participants enrolled at the Colorado center increased nearly threefold, from 3.3 to 9.4 %, after adoption of these methods. In this manuscript, we report on the specialized recruitment methods that were developed and how they were used to address known barriers to Hispanic recruitment.

Background: Many clinical trials rely on participant report to first learn about study events. It is therefore important to have current contact information and the ability to locate participants should information become outdated. The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO) and the Lung Screening Study (LSS) component of the National Lung Screening Trial, two large randomized cancer screening trials, enrolled almost 190,000 participants on whom annual contact was necessary. Ten screening centers participated in both trials. Centers developed methods to track participants and trace them when necessary. We describe the methods used to keep track of participants and trace them when lost, and the extent to which each method was used., Methods: Screening center coordinators were asked, using a self-administered paper questionnaire, to rate the extent to which specific tracking and tracing methods were used., Results: Many methods were used by the screening centers, including telephone calls, mail, and internet searches. The most extensively used methods involved telephoning the participant on his or her home or cell phone, or telephoning a person identified by the participant as someone who would know about the participant's whereabouts. Internet searches were used extensively as well; these included searches on names, reverse-lookup searches (on addresses or telephone numbers) and searches of the Social Security Death Index. Over time, the percentage of participants requiring tracing decreased., Conclusions: Telephone communication and internet services were useful in keeping track of PLCO and LSS participants and tracing them when contact information was no longer valid., (Published by Elsevier Inc.)

Objectives: To report participant recruitment experiences in a large, US randomized controlled trial (RCT) of lung cancer screening, with the aim of providing information that may be of use to researchers who wish to conduct similar future studies., Setting: The National Lung Screening Trial (NLST), an RCT that demonstrated a 20% lung cancer mortality reduction with low dose helical computed tomography screening, relative to single-view chest radiograph screening. Thirty-three US medical centres recruited 53,454 participants from August 2002 through April 2004., Methods: After recruitment was completed, centre co-ordinators were asked to complete a questionnaire addressing the extent to which specific methods were used and, for each specific method, numbers enrolled and total cost of the effort. Cost per enrollee was calculated. Co-ordinators also were asked to report lessons learned., Results: Twenty-two centres returned questionnaires. Use of recruitment method varied by centre. Among centres reporting number enrolled by method, about 19,000 participants were enrolled with direct mail, about 4200 with mass media, and about 1000 with community outreach. Cost per enrollee varied across centres but medians were (US) $101 (direct mail), $79 (mass media), and $4 (community outreach). Co-ordinators reported that it was important to know where to find persons likely to be eligible and interested, and how best to approach them., Conclusions: Most NLST participants were recruited through direct mail, although median cost per participant was highest for that method.

Background: Randomized controlled trials (RCTs) evaluating cancer screening modalities usually employ cause-specific mortality as their primary endpoint. Because death certificate cause of death can be inaccurate, RCTs frequently use review committees to assign an underlying cause of death. We describe the National Lung Screening Trial's (NLST's) death review approach, the Endpoint Verification Process (EVP), which strives to minimize errors in assignment of cause of death due to lung cancer., Methods: Deaths selected for review include those with a notation of lung cancer on the death certificate and those occurring among participants ever diagnosed with lung cancer. Other criteria that trigger death review include, but are not limited to, death within 6 months of a screen suspicious for lung cancer and death within 60 days of certain diagnostic evaluation procedures associated with a screen suspicious for lung cancer or a lung cancer diagnosis. EVP requires concordance on whether death was due to lung cancer. Deaths are first reviewed by the EVP chair. If concordance is not achieved, the death is next reviewed by an Endpoint Verification Team (EVT) member. If concordance between the chair- and member-assigned cause of death is not achieved, the death is next reviewed by a group of at least three EVT members. Cause of death is assigned at the step in which concordance was achieved, or if necessary, at the team review., Conclusions: NLST's EVP is designed to produce a highly accurate count of lung cancer deaths., (Published by Elsevier Inc.)

Background: The National Lung Screening Trial (NLST), a randomized study conducted at 33 US sites, is comparing lung cancer mortality among persons screened with reduced dose helical computerized tomography and among persons screened with chest radiograph. In this article, we present characteristics of the study population., Methods: Eligible participants were aged 55-74 years and were current or former smokers with a cigarette smoking history of at least 30 pack-years. Randomization was stratified by site, sex, and age. To assess representativeness of the study population, demographic characteristics of individuals from the general population who met NLST age and smoking history inclusion criteria were obtained from the Tobacco Use Supplement of the US Census Bureau Current Population Surveys., Results: The NLST enrolled 53 456 persons, with 26 733 randomly assigned to chest radiograph screening and 26 723 to computerized tomography screening. Characteristics of the participants were as follows: 31 533 (59%) were men, 39 234 (73%) were younger than 65 years, 25 779 (48%) were current smokers, and 16 839 (32%) had a college or higher degree. Median cigarette exposure was 48 pack-years. Among Tobacco Use Supplement respondents who met NLST age and smoking history criteria, 59% were men, 65% were younger than 65 years, and 57% were current smokers. Median cigarette exposure among this group was 47 pack-years, and 14% had a college degree or higher., Conclusion: The NLST cohort has a distribution of sex and pack-year history that is similar to the component of the general US population that meets the major NLST eligibility criteria; however, NLST participants are younger, better educated, and less likely to be current smokers.

Background: Direct-to-consumer promotion of lung cancer screening has increased, especially low-dose computed tomography (CT). However, screening exposes healthy persons to potential harms, and cumulative false-positive rates for low-dose CT have never been formally reported., Objective: To quantify the cumulative risk that a person who participated in a 1- or 2-year lung cancer screening examination would receive at least 1 false-positive result, as well as rates of unnecessary diagnostic procedures., Design: Randomized, controlled trial of low-dose CT versus chest radiography. (ClinicalTrials.gov registration number: NCT00006382), Setting: Feasibility study for the ongoing National Lung Screening Trial., Patients: Current or former smokers, aged 55 to 74 years, with a smoking history of 30 pack-years or more and no history of lung cancer (n = 3190)., Intervention: Random assignment to low-dose CT or chest radiography with baseline and 1 repeated annual screening; 1-year follow-up after the final screening. Randomization was centralized and stratified by age, sex, and study center., Measurements: False-positive screenings, defined as a positive screening with a completed negative work-up or 12 months or more of follow-up with no lung cancer diagnosis., Results: By using a Kaplan-Meier analysis, a person's cumulative probability of 1 or more false-positive low-dose CT examinations was 21% (95% CI, 19% to 23%) after 1 screening and 33% (CI, 31% to 35%) after 2. The rates for chest radiography were 9% (CI, 8% to 11%) and 15% (CI, 13% to 16%), respectively. A total of 7% of participants with a false-positive low-dose CT examination and 4% with a false-positive chest radiography had a resulting invasive procedure., Limitations: Screening was limited to 2 rounds. Follow-up after the second screening was limited to 12 months. The false-negative rate is probably an underestimate., Conclusion: Risks for false-positive results on lung cancer screening tests are substantial after only 2 annual examinations, particularly for low-dose CT. Further study of resulting economic, psychosocial, and physical burdens of these methods is warranted., Primary Funding Source: National Cancer Institute.

Background and Aims: Prospective information on the use and yield of surveillance colonoscopy is limited. We examined the use and yield of surveillance colonoscopy among participants in the Polyp Prevention Trial (PPT) after the 4-year dietary intervention trial ended., Methods: We followed a cohort of 1297 participants. We calculated the cumulative probability of posttrial colonoscopy and investigated the yield and predictive factors for adenoma and advanced adenoma recurrence over a mean time of 5.9 years., Results: Seven-hundred seventy-four subjects (59.7%) had a repeat colonoscopy. Among 431 subjects with low-risk adenomas (1-2 nonadvanced adenomas) at baseline and no adenoma recurrence at the end of the PPT (lowest-risk category), 30.3% underwent a repeat colonoscopy within 4 years. Among 55 subjects who had high-risk adenomas (advanced adenoma and/or > or =3 nonadvanced adenomas) at baseline and again at the final PPT colonoscopy (highest-risk category), 41.3% had a colonoscopy within 3 years and 63.5% had an examination within 5 years. The cumulative yield of advanced adenoma through 6 years was 3.6% for the lowest-risk category, 38.9% for the highest-risk category, and ranged from 6.6% to 13.8% for intermediate-risk categories. An advanced adenoma at the final PPT colonoscopy was associated significantly with an advanced adenoma recurrence during surveillance (hazard ratio, 6.2; 95% confidence interval, 2.5-15.4)., Conclusions: Surveillance colonoscopy was overused for low-risk subjects and underused for high-risk subjects. Advanced adenoma yield corresponded with the adenoma risk category. Resource consumption can be better managed by aligning use with the risk of adenoma recurrence.

Background: Multidisciplinary attempts to understand the etiology of breast cancer are expanding to increasingly include new potential markers of disease risk. Those efforts may have maximal scientific and practical influence if new findings are placed in context of the well-understood lifestyle and reproductive risk factors or existing risk prediction models for breast cancer. We therefore evaluated known risk factors for breast cancer in a cancer screening trial that does not have breast cancer as a study endpoint but is large enough to provide numerous analytic opportunities for breast cancer., Methods: We evaluated risk factors for breast cancer (N = 2085) among 70,575 women who were randomized in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Using Poisson regression, we calculated adjusted relative risks [RRs, with 95% confidence intervals (CIs)] for lifestyle and reproductive factors during an average of 5 years of follow-up from date of randomization., Results: As expected, increasing age, nulliparity, positive family history of breast cancer, and use of menopausal hormone therapy were positively associated with breast cancer. Later age at menarche (16 years or older vs. < 12: RR = 0.81, 95% CI, 0.65-1.02) or menopause (55 years or older vs. < 45: RR = 1.29, 95% CI, 1.03-1.62) were less strongly associated with breast cancer than was expected. There were weak positive associations between taller height and heavier weight, and only severe obesity [body mass index (BMI; kg/m(2)) 35 or more vs. 18.5-24.9: RR = 1.21, 95% CI, 1.02-1.43] was statistically significantly associated with breast cancer., Conclusion: The ongoing PLCO trial offers continued opportunities for new breast cancer investigations, but these analyses suggest that the associations between breast cancer and age at menarche, age at menopause, and obesity might be changing as the underlying demographics of these factors change., Clinical Trials Registration: (http://www.clinicaltrials.gov), NCT00002540.

Objective: Recruitment of healthy subjects to long-term randomized controlled trials (RCTs) of cancer prevention or early detection has proven to be a difficult task. To quantify recruitment yield as well as characteristics of successfully recruited participants, we examined recruitment outcomes at 1 of the 10 centers participating in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial, a National Cancer Institute-funded RCT of cancer screening modalities., Materials and Methods: During the early recruitment phase of PLCO (1993-1997), data on recruitment outcome were collected at the Henry Ford Health System (HFHS) in Detroit, Michigan. In this phase, HFHS identified potential participants using patient databases. Records were used to assess recruitment success by age, sex, race, household income (using area-based U.S. Census data), and preexisting morbidity. Logistic regression was used to assess whether enrollment success differed significantly according to these factors., Results: Of 74,139 persons ages 55 to 74 invited by HFHS to participate, 8,250 (11%) ;enrolled. In multivariate analyses, the odds of enrolling were modestly but significantly higher for women, Caucasians, persons in their 60's, and persons living in census blocks with higher median household income. Persons with two or more preexisting morbidities had significantly lower odds of enrolling compared to those with one or no preexisting morbidities., Conclusions: These data suggest that only a small fraction of persons invited to enroll in long-term RCTs of cancer screening modalities actually do so. In this urban, Midwestern setting, certain characteristics including age, race, and income influenced recruitment success, albeit modestly.

Background: Minority populations in the United States, especially blacks and Hispanics, are generally underrepresented among participants in clinical trials. Here, we report the experience of enrolling ethnic minorities in a large cancer screening trial., Methods: The Prostate, Colorectal, Lung and Ovarian (PLCO) Cancer Screening Trial is a multicenter randomized trial designed to evaluate the effectiveness of screening for the PLCO cancers. Subjects were recruited at 10 U.S. centers between 1993 and 2001. One screening center had a major special recruitment effort for blacks and another center had a major special recruitment effort for Hispanics., Results: Among almost 155,000 subjects enrolled in PLCO, minority enrollment was as follows: black (5.0%), Hispanic (1.8%) and Asian (3.6%). This compares to an age-eligible population in the combined catchment areas of the PLCO centers that was 14.0% black, 2.9% Hispanic and 5.4% Asian, and an age-eligible population across the U.S. that was 9.5% black, 6.5% Hispanic and 3.0% Asian. About half (45%) of Hispanics were recruited at the center with the special Hispanic recruitment effort. Seventy percent of blacks were recruited at two centers; the one with the major special recruitment effort and a center in Detroit whose catchment area was 20% black among age-eligibles. Blacks, Hispanics and (non-Hispanic) whites were all more highly educated, less likely to currently smoke and more likely to get regular exercise than their counterparts in the general population., Conclusion: Significant efforts were made to recruit racial/ ethnic minorities into PLCO, and these efforts resulted in enrollment levels that were comparable to those seen in many recent cancer screening or prevention trials. Blacks and Hispanics were nonetheless underrepresented in PLCO compared to their levels among age-eligibles in the overall U.S. population or in the aggregate PLCO catchment areas.

Background: A troubling aspect of cancer screening is the potential for overdiagnosis, i.e., detection of disease that, in the absence of screening, would never have been diagnosed. Overdiagnosis is of particular concern in lung cancer screening because newer screening modalities can identify small nodules of unknown clinical significance. Previously published analyses of data from the Mayo Lung Project, a large randomized controlled trial conducted among 9211 male cigarette smokers in the 1970s and early 1980s indicated that overdiagnosis might exist in lung cancer screening. At the end of follow-up (July 1, 1983), no difference in lung cancer mortality was observed, but an excess of 46 cases in the intervention arm suggested overdiagnosis. Because that excess could instead have resulted from short follow-up time, we investigated this possibility by conducting long-term lung cancer incidence follow-up., Methods: We investigated the lung cancer status through 1999 of the 7118 participants in the Mayo Lung Project who were alive and without diagnosed lung cancer in 1983 by use of medical records, surveys mailed to participants or next-of-kin, and state death certificates., Results: Information was available for 6101 participants, including 811 with inconclusive lung cancer status. From November 1971 through December 31, 1999, 585 participants in the intervention arm and 500 in the usual-care arm were diagnosed with lung cancer., Conclusions: The persistence of excess cases in the intervention arm after 16 additional years of follow-up provides continued support for overdiagnosis in lung cancer screening.

The Lung Screening Study (LSS) was a pilot study designed to assess the feasibility of conducting a large scale randomized controlled trial (RCT) of low radiation dose spiral computed tomography (LDCT) versus chest X-ray (CXR) for lung cancer screening. Baseline results of LSS have been previously reported. Here, we report on the findings at the year one screen and on the final results of the LSS study. A total of 1660 subjects were randomized to the LDCT arm and 1658 to the CXR arm. Compliance with screening declined from 96% at baseline to 86% at year one in the LDCT arm and declined from 93% at baseline to 80% at year one in the CXR arm. Positivity rates for the year one screen were 25.8% for LDCT and 8.7% for CXR. Cancer yield was significantly less at year one for LDCT, 0.57%, than at baseline, 1.9%; cancer yield for CXR increased from 0.45% at baseline to 0.68% at year one. Forty lung cancers in the LDCT arm and 20 in the CXR arm were diagnosed over the study period. Stage I cancers comprised 48% of cases in the LDCT arm and 40% in the CXR arm. A total of 16 stage III-IV cancers were observed in the LDCT arm versus nine in the CXR arm. The LSS has established the feasibility of a RCT comparing annual spiral CT to chest X-ray for lung cancer screening.

Background: Low-radiation dose spiral computed tomography (LDCT) currently is being evaluated as a screening modality for lung carcinoma in a randomized trial. Although several diagnostic algorithms for the workup of positive LDCT screens have been proposed, to the authors' knowledge there is no widely accepted standard to date and there are few nationwide data concerning how such diagnostic workups are actually being performed outside a research protocol setting., Methods: The Lung Screening Study (LSS) was a multicenter feasibility trial that randomized 1660 subjects to undergo LDCT and an equivalent number to undergo chest X-ray. Subjects with positive screens were referred to their own health care providers for diagnostic follow-up; LSS did not specify a diagnostic algorithm. LSS collected and abstracted medical records regarding procedures employed in the diagnostic workup of positive screens., Results: Of the 522 subjects with a positive LDCT screen at baseline or at Year One, 12% underwent biopsy. Biopsy was less likely to be performed in subjects with 4-9-mm nodules (5%) than in subjects with nodules measuring 10+ mm (25%) or in subjects with no nodules but other suspicious findings (15%). Among 63% of the subjects who underwent chest CT on follow-up, the median time between screening and first follow-up chest CT was 82 days. Only a minority of subjects received diagnostic workups that were consistent with published algorithms., Conclusions: The data from the current study represent the experience of subjects followed by their health care providers in five different U.S. metropolitan areas and one rural area. As such, they provide some indication of practices in the U.S. with regard to the diagnostic workup of patients with positive spiral CT screens.

Two prominent and timely issues in lung cancer screening are discussed in this article. First, findings from extended mortality follow-up of participants enrolled as part of the Mayo Lung Project are reviewed. These findings suggest that overdiagnosis-the identification, through screening, of clinically unimportant lung cancer lesions-may occur when screening for lung cancer. Second, the question of whether sufficient evidence exists to advocate mass lung cancer screening with low radiation dose spiral computed tomography (CT) is discussed. Given the absence of lung cancer mortality data for spiral CT, it is concluded that such activities should not be advocated at this point in time. The Lung Screening Study, an ongoing randomized controlled trial of lung cancer screening with spiral CT, also is described.

Background: The Mayo Lung Project (MLP) was a randomized, controlled clinical trial of lung cancer screening that was conducted in 9211 male smokers between 1971 and 1983. The intervention arm was offered chest x-ray and sputum cytology every 4 months for 6 years; the usual-care arm was advised at trial entry to receive the same tests annually. No lung cancer mortality benefit was evident at the end of the study. We have extended follow-up through 1996., Methods: A National Death Index-PLUS search was used to assign vital status and date and cause of death for 6523 participants with unknown information. The median survival for lung cancer patients diagnosed before July 1, 1983, was calculated by use of Kaplan-Meier estimates. Survival curves were compared with the log-rank test., Results: The median follow-up time was 20.5 years. Lung cancer mortality was 4.4 (95% confidence interval [CI] = 3.9-4.9) deaths per 1000 person-years in the intervention arm and 3.9 (95% CI = 3.5-4.4) in the usual-care arm (two-sided P: for difference =.09). For participants diagnosed with lung cancer before July 1, 1983, survival was better in the intervention arm (two-sided P: =.0039). The median survival for patients with resected early-stage disease was 16.0 years in the intervention arm versus 5.0 years in the usual-care arm., Conclusions: Extended follow-up of MLP participants did not reveal a lung cancer mortality reduction for the intervention arm. Similar mortality but better survival for individuals in the intervention arm indicates that some lesions with limited clinical relevance may have been identified in the intervention arm.

Objectives: To examine whether age at entry, history of cigarette smoking, exposure to non-tobacco lung carcinogens, or previous pulmonary illnesses were confounders or effect modifiers of the relation between screening and lung cancer mortality in the Mayo Lung Project., Setting: The Mayo Lung Project was a randomised, controlled, clinical trial conducted between 1971 and 1986 in 9211 male smokers over the age of 45 in Minnesota (USA). The group screened received chest x ray examination and sputum cytology every four months for six years. The unscreened group were recommended to obtain usual care (annual chest x ray examination and sputum cytology). After follow up, lung cancer mortality was similar in both groups., Methods: Proportional hazard models were used to analyse data. A variable was considered a confounder if its inclusion in a model changed the rate ratio for screening by more than 15%; a variable was considered an effect modifier if its stratum-specific rate ratio for screening differed by a factor of two., Results: None of the four aforementioned variables changed the rate ratio associated with screening (1.07) by more than 2%. The effect of screening may have differed by years smoked (rate ratio for smoking fewer than 30 years 2.4; rate ratio for smoking 30 or more years 1.0), though we suspect that this result occurred by chance., Conclusion: Adjustment for or stratification by four established lung cancer risk factors did not alter the original findings of the Mayo Lung Project.