1. Reducing Deaths from Occupational Lung Cancer Laura Welch MD Center for Construction Research and Training

2. Fraction of cancer attributable to occupation in Great Britain, for IARC group I carcinogens
Site
% attributable in men
% attributable in women
total
Leukemia
0.3%
0.5%
0.2%
Bladder
1.3%
0.6% 1%
Non-melanoma skin cancer
11.8% 3%
8.4%
Lung
16.5%
4.5%
11.6%
Attributable fraction here is very similar to what Steenland published in 2003.
Will list the group 1 carcinogens in subsequent slide
Rushton et al Burden of cancer at work. Occup Env Med 65:

3. Fraction of cancer attributable to occupation in Great Britain, for IARC groups I and strong 2A carcinogens
Site
% attributable in men
% attributable in women
total
Leukemia
2.7%
0.8%
1.7%
Bladder
11.3% 2%
8.3%
Non-melanoma skin cancer
11.8% %
8.4%
Lung
21.6%
5.5%
15%
Rushton et al Burden of cancer at work. Occup Env Med 65:

4. Brown et al Br J Ca 2012. Occupational cancer in Britain. 107:S56-S70
This does not display all the Group 1 agents but shows the ones with the largest attributable fractions.
Asbestos exposure was widespread in US and parts of Europe through the 1970s, and with a long latency those exposures are still causing disease but should begin to decline.
You can see from this slide that we might concentrate screening to specific occupations with these high risk exposures.
Brown et al Br J Ca Occupational cancer in Britain. 107:S56-S70

5. Risk from occupational exposure in non-smokers
Study author
Study design
Exposure RR
Pohlabeln
Case control, non smokers
Ever worked in list A occupation
1.52
Kruezer
Case control, non smokers, men only
2.4
Neuberger
Case control, non smokers, women only
Occupational exposure to asbestos
4.38
Frost
Cohort study
1.9
Zeka
Ever exposed to silica
1.76
Cassidy
Occupational exposure to silica
1.51
Tse
3.09
Studies are limited by small numbers of lung cancers in non smokers, but most studies show increased risk from occupation in non smokers. CI’s are wide for these estimates, and other studies do not show an increased RR

6. NCCN Guidelines High-risk, category 1: High-risk, category 2B:
55 to 74 years old
at least a 30 pack-year history of smoking
smoking cessation for less than 15 years
High-risk, category 2B:
at least 50 years old
20 or more pack-year history of smoking
1 additional risk factor: COPD, occupational exposures, radon exposure, family history
You are all familiar with these recommendations. Category 2B starts screening at an earlier age and does not specify recent smoking, as long as there is another risk factor present
NCCN guidelines do not give any guidance how to incorporate occupational exposure.

7. American Association of Thoracic Surgery
Annual LDCT screening for smokers and former smokers aged with 30 pack year history
Annual LDCT screening for smokers and former smokers aged with 20 pack year history and additional co-morbidity that produces a cumulative risk of lung cancer >5% over subsequent 5 years
Annual screening for lung cancer survivors
This differs from NCCN: starts at age 55 for everyone.
Specifies a risk for lung cancer over 5% - do we have models that will let us calculate those risks?
An approach that allows calculation of individual risk is preferable, as long as the data going into it is sound and precise.
For discussion, is that 5% number the right one, or is it arbitrary?

8. Who’s eligible for BTMed lung cancer screening?
Age years old
Current or former smoker with significant smoking history
(20 Pack years with no restriction on time since quit)
CXR shows asbestosis, may be eligible without meeting smoking criteria
Worked Construction or DOE work > 5 years
CXR shows pleural plaques or COPD on spirometry (must also meet smoking criteria, but does not have to meet > 5 yrs work history)

9. Exclusion criteria Spirometry with FEV1 < 40%
Previously diagnosed with lung cancer or have another cancer that has been diagnosed or treated within past 5 years.
Symptoms suspicious for lung cancer
Health problem that substantially limits life expectancy or unwillingness to have curative surgery.

10. Model of continuum of care from Lung Cancer Alliance - Overview
Provide clear information on risks and benefits of the screening process in language appropriate to the candidate. Follow comprehensive standards for screening quality, radiation dose and diagnostic procedures such as those from ACR, NCCN and IELCAP Work with a multi-disciplinary clinical team to carry out a coordinated continuum of care for screening, diagnosis and disease management: Experienced radiologists, pathologists and pulmonologists to evaluate the images/specimens; Trained thoracic surgeons with experience in minimally invasive techniques; Oncologists and radiation oncologists experienced in lung cancer; Nurses and support staff who will assist patients with lung cancer; Include a comprehensive smoking cessation program in screening and continuum of care program based on best practices evidence.

11. Model of continuum of care from Lung Cancer Alliance – a specific example
Lung cancer screening consistent with Level 1A data and NCCN/IELCAP guidelines.
Pulmonary medicine with bronchoscopy, image guided biopsy (SuperD), EBUS services.
Thoracic surgery with expertise in VATS procedures and VATS lobectomy with complete staging through lymphadenectomy, subscribing to the STS General Thoracic Surgery Database.
Medical oncologic treatment consistent with NCCN guidelines and with access to clinical trials for all stages.
Radiation oncology with state-of-the-art technology and CyberKnife therapy.
Pathology with specific pulmonary expertise and access to genomic tissue profiling.
Diagnostic and interventional radiology have direct interface with multi-disciplinary team for nodule evaluation.

12. ELCD Screening results
Outcome
All scans
Baseline
1st annual
2nd+ annual
1290
Follow-up
356
236 57 63
Annual
1659
898
761
Indeterminate
194
154 30 18
Suspicious
117 76 20 23
Non small cell
Stage 1 17 13 2
Stage II 3 1
Stage III
Stage 4 6 5
Small cell 4

13. 614 Referred for non-cancer findings
Renal cancer
Liver cancer
Thyroid nodules/ thyroid cancer
Esophageal cancer
Throat cancer
Breast nodules
Adrenal tumors
Aortic aneurysm
Emphysema/ COPD
Interstitial lung disease
Asbestosis
Pleural plaques
Pancreatitis
Coronary artery plaque
Aorta & heart valve calcification
Enlarged lymph nodes
Degenerative bone
Kidney stones & gallstones

14. IARC group 1 occupational lung carcinogens
Dust:
Asbestos
Silica
Metals:
Beryllium
Nickel
Chromium
Cadmium
Arsenic
Diesel exhaust, combustion products
Uranium, plutonium, radon and other radioactive materials
PAH
Environmental tobacco smoke
Working as painter or welder

15. This is based on the Bach model, I couldn’t find an on-line version for LLP model.
You see that this nomogram include occupational exposures, but in a limited fashion

16. Definition of asbestos exposure in Memorial/Sloan on-line model
Work in one or more of the following occupations: asbestos worker, insulator, lagger, plasterboard worker, dry waller, plasterer, ship scaler, ship fitter, rigger, shipyard boilermaker, shipyard welder, shipyard machinist, shipyard coppersmith, shipyard electrician, plumber/pipefitter, steamfitter, or sheet metal worker.
Worked in this job for at least 5 years and began working in this job at least 15 years ago.
These are high risk tasks that were defined for the CARET study – this was a large multi-center randomized intervention trial to test the hypothesis that B-carotene (vit A) would prevent lung cancer (it didn’t). CARET included a subset of individuals with a high risk of lung cancer from asbestos exposure. Bach used CARET to develop risk model from smoking and also incorporated asbestos exposure.
So a “yes” exposure to asbestos is not any asbestos, it is 5 years of work in a high risk trade before 1980.
Given that workers in these jobs usually started after high school, a 55 year old today would have started before 1980, most before 1970
This list does not include all high exposure asbestos work – you can see it focuses on shipyard work and construction trades. That was based on the participating institutions and the populations they could recruit for the trial.

17. Risk model from Memorial/Sloan Kettering, based on Bach model with assumed synergy between RR of exposure and risk of smoking
AGE
YEARS SMOKED
CIGARETTES PER DAY
YEARS SINCE QUIT
ASBESTOS
10 YR RISK IF CONTINUES TO SMOKE
10 YR RISK IF QUITS NOW OR IS NON SMOKER 50 25 20 10
Yes No -- 2% 1% 35 60 6% 3% 45
14% 7%
10% 5% 65 40
20%
I carried over correction from last slide, 2% to 1% in second row of second example.
Here I have assigned a RR of 2 for asbestos exposure based on Steenland estimate, and simply multiplied the risk from smoking in the Bach model by 2.
You can see how much it changes the risk for some of the workers, and would move those 60 yr olds into groups that need to be screened even if is an ex smoker

18. Projected 5 year absolute from LLP model (men)
Age
Yrs smoked
FH lung ca
Any cancer?
pneumonia
asbestos
5 yr risk 64 42
Late onset* No
9.53% 66 53
Yes
8.75% 67
Early onset*
3.16% 73 59
Late onset
27.09% 77
Early onset
3.17%
Liverpool Lung Project, taken from tables in cited publication
This model also includes FH of lung cancer, history of pneumonia
Authors set asbestos exposure as yes/no for simplicity sake, but their underlying population had high exposures, likely similar to CARET
Walk thru examples – show the high risk one who is 73, heavy current smoker
In this model a non-smoker comes close to warranting screening – last line
* Early = < 60 yrs at diagnosis, Late = 60+ years at diagnosis
Cassidy et al The LLP risk model: an individual risk prediction model for lung cancer. Br J Cancer 98:

19. Deval et al BMCPH 2017 Agent RR for agent
Estimated risk level with smoking
< 20 p-y
20-29 p-y
> 30 p-y
Tobacco alone 10 20 30
Asbestos med < 10 yr
1.5 15 45
Asbestos high > 5 yr 3 60 90
Silica

20. Deval et al: Definition of high-risk subjects (55 to 74 years)
Agent Cumulative level Cumulative duration Active/quit < 15 y
Asbestos Intermediate ≥10 years ≥30 PY
High <5 years ≥30 PY High ≥5 years ≥20 PY
Asbestosis ≥20 PY
Pleural plaques ≥30 PY
Other carcinogenic agents ≥10 years ≥30 PY
Co-exposure
2 carcinogenic agents ≥10 years ≥20 PY
≥ 3 carcinogenic agents ≥10 years ≥10 PY

21. Workers with occupational risk often are current smokers MMWR September 30, 2011 / 60(38);1305-1309
Working adults (millions)
Smoking prevalence (age adjusted) NHIS
Smoking prevalence (age adjusted) 2000
IARC carcinogens
Construction and extraction
8.4
31.4%
41.3%
Asbestos, silica, almost all group I
Transportation
8.1
28.7%
40.5%
Diesel exhaust
Food preparation and serving 7
30%
39.8%
ETS
Installation, repair 5
27.2%
Similar to construction
Production 9
26.1%
36.2%
Varies by industry
Management
13.2
16.3%
19.9% ??
Education
8.9
8.7%
9.6%
So if screening programs target the workers with high rates of smoking may also be capturing the occupational risk as well!

22. Conclusions
20% of lung cancer in men are attributable to occupational exposures (esp asbestos, diesel and silica)
High risk occupations are well known
50% of lung cancer in construction workers is attributable to occupation
We currently have the knowledge to develop a risk assessment tool for occupational exposures
Those high risk workers should be recruited for LDCT screening

23. Reaching high risk workers using continuum of care
BTMed is using partnerships between NCI regional cancer centers and local hospitals in rural areas
Outreach through retiree clubs, union newsletters, public meetings
Other ideas?