Self-Selection Effects in Smokers Attending Lung Cancer Screening: A 9.5-Year Population-Based Cohort Study in Varese, Italy

Concurrent participation in screening for cervical, breast, and bowel cancer in England

Objectives

To determine how many women participate in all three recommended cancer screening programmes (breast, cervical, and bowel). During their early 60s, English women receive an invitation from all the three programmes.

Methods

For 3060 women aged 60–65 included in an England-wide breast screening case–control study, we investigated the number of screening programmes they participated in during the last invitation round. Additionally, using the Fingertips database curated by Public Health England, we explored area-level correlations between participation in the three cancer screening programmes and various population characteristics for all 7014 English general practices with complete data.

Results

Of the 3060 women, 1086 (35%) participated in all three programmes, 1142 (37%) in two, 526 (17%) in one, and 306 (10%) in none. Participation in all three did not appear to be a random event (p < 0.001). General practices from areas with less deprivation, with more patients who are carers or have chronic illnesses themselves, and with more patients satisfied with the provided service were significantly more likely to attain high coverage rates in all programmes.

Conclusions

Only a minority of English women is concurrently protected through all recommended cancer screening programmes. Future studies should consider why most women participate in some but not all recommended screening.

New recommendation and coverage of low-dose computed tomography for lung cancer screening: uptake has increased but is still low

Background

In 2013, the US Preventive Services Task Force (USPSTF) issued recommendations for low-dose computed tomography for lung cancer screening (LDCT-LCS), but there continues to be a dearth of information on the adoption of LDCT-LCS in healthcare systems. Using a multilevel perspective, our study aims to assess referrals for LDCT-LCS and identify facilitators and barriers to adoption following recent policy changes.

Methods

A retrospective analysis of electronic medical record data from patients aged 55–80 years with no history of lung cancer who visited a primary care provider in a large healthcare system in California during 2010–2016 (1,572,538 patient years). Trends in documentation of smoking history, number of eligible patients, and lung cancer screening orders were assessed. Using Hierarchical Generalized Linear Models, we also evaluated provider-level and patient-level factors associated with lung cancer screening orders among 970 primary care providers and 12,801 eligible patients according to USPSTF guidelines between January 1st, 2014 and December 31st, 2016.

Results

Documentation of smoking history to determine eligibility (59.2% in 2010 to 77.8% in 2016) and LDCT-LCS orders (0% in 2010 to 7.3% in 2016) have increased since USPSTF guidelines. Patient factors associated with increased likelihood of lung cancer screening orders include: younger patient age (78–80 vs. 55–64 years old: OR, 0.4; 95% CI, 0.3–0.7), Asian race (vs. Non-Hispanic White: OR, 1.6; 95% CI, 1.1–2.4), reported current smoking (vs. former smoker: OR, 1.7; 95% CI, 1.4–2.0), no severe comorbidity (severe vs. no major comorbidity: OR = 0.2, 95% CI = 0.1–0.3; moderate vs. no major comorbidity: OR = 0.5; 95% CI = 0.4–0.7), and making a visit to own primary care provider (vs. other primary care providers: OR, 2.4; 95% CI, 1.7–3.4). Appropriate referral for lung cancer screening varies considerably across primary care providers. Provider factors include being a female physician (vs. male: OR, 1.6; 95% CI, 1.1–2.3) and receiving medical training in the US (foreign vs. US medical school graduates: OR = 0.4, 95% CI = 0.3–0.7).

Conclusions

Future interventions to improve lung cancer screening may be more effective if they focus on accurate documentation of smoking history and target former smokers who do not regularly see their own primary care providers.

Lung Cancer Screening Participation: Developing a Conceptual Model to Guide Research

PURPOSE

To describe the development of a conceptual model to guide research focused on lung cancer screening participation from the perspective of the individual in the decision-making process.

METHODS

Based on a comprehensive review of empirical and theoretical literature, a conceptual model was developed linking key psychological variables (stigma, medical mistrust, fatalism, worry, and fear) to the health belief model and precaution adoption process model.

RESULTS

Proposed model concepts have been examined in prior research of either lung or other cancer screening behavior. To date, a few studies have explored a limited number of variables that influence screening behavior in lung cancer specifically. Therefore, relationships among concepts in the model have been proposed and future research directions presented.

CONCLUSION

This proposed model is an initial step to support theoretically based research. As lung cancer screening becomes more widely implemented, it is critical to theoretically guide research to understand variables that may be associated with lung cancer screening participation. Findings from future research guided by the proposed conceptual model can be used to refine the model and inform tailored intervention development.

Resection rate of lung cancer in Teesside (UK) and Varese (Italy): a comparison after implementation of the National Cancer Plan

BACKGROUND

In a lung cancer survey in 2000 we showed significantly less favourable stage distribution and lower resection rate in Teesside (UK) than in the comparable industrialised area of Varese (Italy). Lung cancer services in Teesside were subsequently reorganised according to National Cancer Plan recommendations.

METHODS

For all new lung cancer cases diagnosed in Teesside (n=324) and Varese (n=260) during the 12 months October 2010 to September 2011 (hereafter 'the 2010 cohort'), demographic, clinico-pathological and disease management data were prospectively recorded using the same database and protocol as the 2000 survey. Findings were analysed focusing on resection rate.

RESULTS

In the 2010 cohort compared with 2000, both in Teesside and Varese emergency referral decreased (p<0.001), performance status improved (p<0.001), but cancer stage shift was not seen; resection rate improved in Teesside, from 7% to 11% (p=0.054), and was unchanged in Varese (24%). Moreover, in Teesside compared with Varese the stage distribution remained less favourable, stage I-II non-small cell lung cancer (NSCLC) proportion being respectively 12% and 19% (p=0.040), and resection rate in all lung cancers remained lower (11% and 24%; p<0.001). On multivariate analysis, resection predictors in Teesside were as follows: stage I-II NSCLC (OR 86.14; 95% CI 31.80 to 233.37), performance status 0-1 (OR 5.02; 95% CI 1.48 to 17.07), belonging to 2010 cohort (OR 2.85; 95% CI 1.06 to 7.64).

CONCLUSIONS

In Teesside the main independent predictor of resection was disease stage; in 2010-2011 compared with 2000, lung cancer service improved but stage shift did not occur, and resection rate increased but remained significantly lower than in Varese.

Is chest X-ray screening for lung cancer in smokers cost-effective? Evidence from a population-based study in Italy

Background

After implementation of the PREDICA annual chest X-ray (CXR) screening program in smokers in the general practice setting of Varese-Italy a significant reduction in lung cancer-specific mortality (18 %) was observed. The objective of this study covering July 1997 through December 2006 was to estimate the cost-effectiveness of this intervention.

Methods

We examined detailed information on lung cancer (LC) cases that occurred among smokers invited to be screened in the PREDICA study (Invitation-to-screening Group, n = 5815 subjects) to estimate costs and quality-adjusted life-years (QALYs) from LC diagnosis until death. The control group consisted of 156 screening-eligible smokers from the same area, uninvited and unscreened, who developed LC and were treated by usual care. We calculated the incremental net monetary benefit (INMB) by comparing LC management in screening participants (n = 1244 subjects) and in the Invitation-to-screening group versus control group.

Results

The average number of QALYs since LC diagnosis was 1.7, 1.49 and 1.07, respectively, in screening participants, the invitation-to-screening group, and the control group. The average total cost (screening + management) per LC case was higher in screening participants (€17,516) and the Invitation-to-screening Group (€16,167) than in the control group (€15,503). Assuming a maximum willingness to pay of €30,000/QALY, we found that the intervention was cost-effective with high probability: 79 % for screening participation (screening participants vs. control group) and 95 % for invitation-to-screening (invitation-to-screening group vs. control group).

Conclusions

Based on the PREDICA study, annual CXR screening of high-risk smokers in a general practice setting has high probability of being cost-effective with a maximum willingness to pay of €30,000/QALY.

Assessing generalizability of the findings of sigmoidoscopy screening trials: the case of SCORE trial

BACKGROUND

Several reports indicated that volunteers enrolled in preventive trials tend to show a different profile, with respect to sociodemographic characteristics, health-related behaviors, or medical history, compared with the source population. We conducted an incidence and mortality follow-up within a cohort of subjects who had been mailed a recruitment questionnaire in the SCORE trial of sigmoidoscopy (FS) screening for colorectal cancer (CRC) to assess the impact of self-selection in the study of volunteers willing to be screened on the outcomes estimates and on the generalizability of the results.

METHODS

We compared baseline demographics, CRC risk, and overall mortality at 11-year follow-up of responders declaring their interest in screening, with those of nonresponders and of responders not interested in screening using logistic regression and Cox proportional hazards multivariable models.

RESULTS

Both subjects who volunteered in the trial and those who refused were better educated than nonresponders. Men and people younger than age 60 years were more likely to volunteer among responders. At 11-year follow-up, interested responders showed a similar CRC risk as nonresponders, while CRC mortality was substantially reduced (hazard ratio [HR] = 0.70, 95% confidence interval [CI] = 0.54 to 0.91). All-cause mortality was reduced both among interested (HR = 0.61, 95% CI = 0.57 to 0.65) and uninterested responders (HR = 0.81, 95% CI = 0.76 to 0.86).

CONCLUSION

The implementation of an FS population-based screening program would result in a similar reduction in CRC incidence, as observed in the SCORE trial, and likely in a larger impact on CRC mortality.

Comparing benefits from many possible computed tomography lung cancer screening programs: extrapolating from the National Lung Screening Trial using comparative modeling

BACKGROUND

The National Lung Screening Trial (NLST) demonstrated that in current and former smokers aged 55 to 74 years, with at least 30 pack-years of cigarette smoking history and who had quit smoking no more than 15 years ago, 3 annual computed tomography (CT) screens reduced lung cancer-specific mortality by 20% relative to 3 annual chest X-ray screens. We compared the benefits achievable with 576 lung cancer screening programs that varied CT screen number and frequency, ages of screening, and eligibility based on smoking.

METHODS AND FINDINGS

We used five independent microsimulation models with lung cancer natural history parameters previously calibrated to the NLST to simulate life histories of the US cohort born in 1950 under all 576 programs. 'Efficient' (within model) programs prevented the greatest number of lung cancer deaths, compared to no screening, for a given number of CT screens. Among 120 'consensus efficient' (identified as efficient across models) programs, the average starting age was 55 years, the stopping age was 80 or 85 years, the average minimum pack-years was 27, and the maximum years since quitting was 20. Among consensus efficient programs, 11% to 40% of the cohort was screened, and 153 to 846 lung cancer deaths were averted per 100,000 people. In all models, annual screening based on age and smoking eligibility in NLST was not efficient; continuing screening to age 80 or 85 years was more efficient.

CONCLUSIONS

Consensus results from five models identified a set of efficient screening programs that include annual CT lung cancer screening using criteria like NLST eligibility but extended to older ages. Guidelines for screening should also consider harms of screening and individual patient characteristics.

Quality of life and healthcare use in a randomized controlled lung cancer screening study

RATIONALE

Understanding the quality of life of lung cancer screening program participants, and the impact of program participation on quality of life and healthcare use, will help in the assessment of the value of screening.

OBJECTIVES

Determine the quality of life of participants in a lung cancer screening study and assess the effect of an abnormal screening finding on quality of life and healthcare use.

METHODS

Quality-of-life measures and data on the use of healthcare services were collected prospectively during a randomized controlled lung cancer screening trial using chest radiography with computer-aided detection. Comparisons of baseline measures were made with U.S. population norms for the EuroQol 5-Dimension index. The impact of receiving a message of the presence of a lung nodule was assessed for all measures.

MEASUREMENTS AND MAIN RESULTS

A total of 1,424 subjects participated. Twenty-five actionable nodules were reported. Baseline EuroQol 5-Dimension index scores were higher than U.S. population norms (P < 0.0001). The EuroQol 5-Dimension index score and St. George's Respiratory Questionnaire symptom score showed a significant change toward poorer quality of life after notification of the presence of a lung nodule (0.940 vs. 0.877, P = 0.022, and 25.7 vs. 34.0, P = 0.005, respectively). Chest imaging within 6 months of the screening examination occurred more frequently in those notified of a lung nodule (25.5 vs. 9.3%, P = 0.002).

CONCLUSIONS

Those who choose to enter a lung cancer screening program have a high baseline quality of life. The report of an abnormal screening finding can lower the quality of life and lead to increased chest imaging. Clinical trial registered with www.clinicaltrials.gov (NCT01663155).

Assessment of lung cancer mortality reduction after chest X-ray screening in smokers: a population-based cohort study in Varese, Italy

BACKGROUND

The effectiveness of screening for lung cancer (LC) in smokers on a population level, as distinct from the special circumstances that may apply in a randomized trial of selected volunteers, has not been thoroughly investigated. Here we evaluate by the standardized mortality ratio (SMR) indicator the impact of a chest X-ray (CXR) screening programme carried out at community level on LC mortality in smokers.

METHODS

All smokers of >10 pack-years, of both genders, ages 45-75 years, resident in 50 communities of the Province of Varese, Italy, screening-eligible, in 1997 were invited by their National Health Service (NHS) general practitioner physicians to a nonrandomized programme of five annual CXR screenings. The entire invitation-to-screen cohort (n=5815 subjects) received NHS usual care, with the addition of CXR exams in volunteer participants (21% of invitees), and was observed through December 2006. To overcome participants' selection bias of LC mortality assessment, for the entire invitation-to-screen cohort we estimated the LC-specific SMR, based on the local reference population receiving the NHS usual care.

RESULTS

Over the 8-year period 1999-2006, a total of 172 cumulative LC deaths were observed in the invitation-to-screen cohort; 210 were expected based on the reference population. Each year in the invited cohort the observed LC deaths were fewer than expected. The cumulative LC SMR was 0.82 (95% CI, 0.67-0.99; p=0.048), suggesting that LC mortality was reduced by 18% with CXR screening.

CONCLUSION

Implementation of a CXR screening programme at community level was associated with a significant reduction of LC mortality in smokers.

Generalisability of the results of the Dutch-Belgian randomised controlled lung cancer CT screening trial (NELSON): does self-selection play a role?

The degree of self-selection in the Dutch-Belgian randomised controlled lung cancer screening trial (NELSON) was determined to assess the generalisability of the study results. 335,441 (mainly) men born in 1928-1953 received a questionnaire. Of the respondents (32%), eligible subjects were invited to participate (19%). Fifty-five percent gave informed consent and was randomised. Background characteristics were compared between male respondents on the first questionnaire (n = 92,802), eligible subjects among them (n = 18,570) and those randomised (n = 10,627) and Statistics Netherlands 2002-2005 (SN) (n = 5289) or GLOBE study-data (Dutch cohort) (n = 696). Initial respondents were less likely to be highly educated (OR(adj) = 0.84; 95% CI: 0.74-0.96) and comprised of significantly less current smokers (OR(adj) = 0.65; 95% CI: 0.61-0.69) compared to the general population. These current smokers smoked more heavily (OR(adj) = 1.23; 95% CI: 1.10-1.37), but for a shorter time-period (respondents: 31, SN: 42 years, p < 0.001). Age, general health, BMI, alcohol use and cancer prevalence were comparable. The randomised population was younger (Age 50-65) (randomised subjects: 85.3%, SN: 72% (p < 0.01)) comprised of more heavy current smokers (OR = 2.08; 95% CI: 1.75-2.44), that smoked for a shorter period of time (randomised subjects: 37, SN_selection: 42 years (p < 0.001)). Both the respondents (32%) of the first questionnaire as well as the randomised population of the NELSON trial appeared to differ slightly on smoking characteristics, but the differences were limited and probably balance each other. Results of the NELSON trial will be roughly applicable to the Dutch and probably other populations that fulfil our selection criteria.

Early lung cancer detection using the self-evaluation scoring questionnaire and chest digital radiography: a 3-year follow-up study in China

The standard definition of high-risk individuals for lung cancer was not uniform and the value of chest digital radiography (DR) in lung cancer screening was still unproven. The aim of this study was to assess whether the original questionnaire named as "Self-evaluation Scoring Questionnaire for High-risk Individuals of Lung Cancer" combined with DR examinations could detect early stage of lung cancer effectively. The Self-evaluation Scoring Questionnaire for High-risk Individuals of Lung Cancer had been designed in previous studies. Subjects with scores over 116 points were regarded as high-risk individuals and underwent the current DR scans at least once a year from 2007 to 2009. Noncalcified nodules with a diameter over 30 mm, along with enlarged pulmonary hilus and atelectasis, were considered to be positive and subjected to further special examinations. Efficacy of the scoring questionnaire combined with DR scans was estimated by 3-year results. Among 1,537 subjects, 13, 11, and 7 were diagnosed with lung cancer in the first, second, and third year, respectively, indicating the detection rate of 2.02 % (31/1,537). In addition, 77.42 % (24/31) of the patients were in stage I and 51.61 % (16/31) were adenocarcinomas. For the 31 cases, 28 were defined as detected cancers, while the other three were interval ones, only accounting for 0.20 % (3/1,504) of individuals with negative judgments. The protocol of Self-evaluation Scoring Questionnaire for High-risk Individuals of Lung Cancer combined with DR scans is a cost-effective and safe approach to detect early stage of lung cancer.

A population-based cohort study of chest x-ray screening in smokers: lung cancer detection findings and follow-up

BACKGROUND

Case-control studies of mass screening for lung cancer (LC) by chest x-rays (CXR) performed in the 1990s in scarcely defined Japanese target populations indicated significant mortality reductions, but these results are yet to be confirmed in western countries. To ascertain whether CXR screening decreases LC mortality at community level, we studied a clearly defined population-based cohort of smokers invited to screening. We present here the LC detection results and the 10-year survival rates.

METHODS

The cohort of all smokers of > 10 pack-years resident in 50 communities of Varese, screening-eligible (n = 5,815), in July 1997 was invited to nonrandomized CXR screening. Self-selected participants (21% of cohort) underwent screening in addition to usual care; nonparticipants received usual care. The cohort was followed-up until December 2010. Kaplan-Meier LC-specific survival was estimated in participants, in nonparticipants, in the whole cohort, and in an uninvited, unscreened population (control group).

RESULTS

Over the initial 9.5 years of study, 67 LCs were diagnosed in screening participants (51% were screen-detected) and 178 in nonparticipants. The rates of stage I LC, resectability and 5-year survival were nearly twice as high in participants (32% stage I; 48% resected; 30.5% 5-year survival) as in nonparticipants (17% stage I; 27% resected; 13.5% 5-year survival). There were no bronchioloalveolar carcinomas among screen-detected cancers, and median volume doubling time of incidence screen-detected LCs was 80 days (range, 44-318), suggesting that screening overdiagnosis was minimal. The 10-year LC-specific survival was greater in screening participants than in nonparticipants (log-rank, p = 0.005), and greater in the whole cohort invited to screening than in the control group (log-rank, p = 0.001). This favourable long-term effect was independently related to CXR screening exposure.

CONCLUSION

In the setting of CXR screening offered to a population-based cohort of smokers, screening participants who were diagnosed with LC had more frequently early-stage resectable disease and significantly enhanced long-term LC survival. These results translated into enhanced 10-year LC survival, independently related to CXR screening exposure, in the entire population-based cohort. Whether increased long-term LC-specific survival in the cohort corresponds to mortality reduction remains to be evaluated.

TRIAL REGISTRATION NUMBER

ISRCTN90639073.

Cost-effectiveness of computed tomography screening for lung cancer in the United States

INTRODUCTION

A randomized trial has demonstrated that lung cancer screening reduces mortality. Identifying participant and program characteristics that influence the cost-effectiveness of screening will help translate trial results into benefits at the population level.

METHODS

Six U.S. cohorts (men and women aged 50, 60, or 70 years) were simulated in an existing patient-level lung cancer model. Smoking histories reflected observed U.S. patterns. We simulated lifetime histories of 500,000 identical individuals per cohort in each scenario. Costs per quality-adjusted life-year gained ($/QALY) were estimated for each program: computed tomography screening; stand-alone smoking cessation therapies (4-30% 1-year abstinence); and combined programs.

RESULTS

Annual screening of current and former smokers aged 50 to 74 years costs between $126,000 and $169,000/QALY (minimum 20 pack-years of smoking) or $110,000 and $166,000/QALY (40 pack-year minimum), when compared with no screening and assuming background quit rates. Screening was beneficial but had a higher cost per QALY when the model included radiation-induced lung cancers. If screen participation doubled background quit rates, the cost of annual screening (at age 50 years, 20 pack-year minimum) was below $75,000/QALY. If screen participation halved background quit rates, benefits from screening were nearly erased. If screening had no effect on quit rates, annual screening costs more but provided fewer QALYs than annual cessation therapies. Annual combined screening/cessation therapy programs at age 50 years costs $130,500 to $159,700/QALY, when compared with annual stand-alone cessation.

CONCLUSIONS

The cost-effectiveness of computed tomography screening will likely be strongly linked to achievable smoking cessation rates. Trials and further modeling should explore the consequences of relationships between smoking behaviors and screen participation.

Participation bias in a randomised trial of screening for lung cancer

INTRODUCTION

Participation bias might affect the results and the representability of randomised controlled trials. We investigated the degree of socio-demographic and psychosocial participation bias in the Danish Lung Cancer Screening Trial (DLCST).

METHODS

In DLCST the questionnaire COS-LC (Consequences of Screening in Lung Cancer) was used to measure the psychosocial aspects of screening. To investigate a difference with a comparable representative sample from the Danish population, we sent out an inclusion questionnaire to 3999 Danes in the age from 50 to 70 years randomly selected from the Central National Register. Those who completed the inclusion questionnaire and met the inclusion criteria from DLCST received the COS-LC. Those who completed the COS-LC-and thus formed a population sample comparable to DLCST - were compared to the DLCST participants on socio-demographics and psychosocial measures.

RESULTS

Participation rates were high among the comparable population sample: 75.3% completed the inclusion questionnaire and 77.4% of those who were eligible completed the COS-LC. The analyses revealed differences between the DLCST participants and the comparable population sample in the following socio-demographic aspects: social group, living alone, gender, age and geographical area. DLCST participants reported less negative psychosocial aspects than the comparable population sample.

CONCLUSION

The present study has shown substantial socio-demographic and psychosocial participation bias in DLCST.

Volunteer effect and compromised randomization in the Mayo Project of screening for lung cancer

It has been confirmed recently that the volunteer effect in lung cancer screening is characterized by higher lung cancer mortality risk in self-selected screening participants. The Mayo Lung Project, the most influential trial of screening for lung cancer ever completed, was conducted in nonvolunteer Mayo Clinic outpatients, with a peculiar study design that rendered the randomization vulnerable to the volunteer effect. Of all nonvolunteers randomized in the Mayo Lung Project, only those allocated in the screened group were asked consent to participate in the trial. The final Mayo Lung Project report stated that 655 randomized nonvolunteers refused screening and were excluded from the study, thus documenting violation of the rule that no selection should occur after randomization. The long-term follow-up of the Mayo Lung Project showed an enigmatic result which has never been explained: the lung cancer mortality was 13% higher in the screening intervention group than in the control group [4.4 (95% CI 3.9-4.9) vs. 3.9 (95% CI 3.5-4.4) per 1,000 person-years; P = 0.09]. Such overrepresented mortality is consistent with the volunteer effect and supports the concept that the Mayo Lung Project randomization was compromised by the post-randomization self-selection of participant nonvolunteers.