WA Asbestos Review Program

Transcription

1 WA Asbestos Review Program Dr Fraser Brims Consultant Respiratory Physician, SCGH, Head of Occupational and Respiratory Health Unit, LIWA Asbestos awareness week seminar, 2014

2 Introduction Asbestos and the lung Legacy of asbestos in WA WA mesothelioma registry Asbestos Review Program Results of 2 years of low dose CT screening

3 Asbestos and the lung Benign effects Pleural plaques Rolled atelectasis Diffuse pleural thickening Benign asbestos related pleural effusion Asbestosis Malignant Malignant mesothelioma Lung cancer

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5 Asbestos Exposure at Wittenoom Machine miner Machine bagger (new mill) Hand bagger (new mill) Hand bagger (old mill) New mill average Old mill average f/cc

6 Western Australia Mesothelioma Register 1971-

7 Mesothelioma is not going away Olsen, MJA 2011

8 Asbestos Review Program (ARP) 1990 surviving members of Wittenoom workers cohort invited to take part in cancer prevention program Regular annual surveillance 2007 analysis demonstrated no benefit

9 Asbestos Review Program (ARP) Non-Wittenoom cohort also developed 3 months full time equivalent of occupational exposure to asbestos Presence of pleural plaques Mixed fibre, low-medium exposure Majority of the cohort

10 Trades Carpenters, joiners, builder Plumber Boilermakers Fitters, turners, machinists Telecommunications Mechanic, fitter, panel beaters Marine engineers Shipwrights Waterside workers

11 ARP End 2013 n=4241 (3462 men) participated Smoking, alcohol, dietary questionnaires Blood (biomarkers, DNA) Lung function (FEV 1, FVC, DLCO) Annual CXR* 1,333 deaths all causes 197 lung cancer 189 mesothelioma

12 2012: Introduction of low dose CT - Rationale Until 2012: annual CXRs (i.e. pre-screened) CT and CXR Asbestos causes lung cancer too Carefully controlled LDCT screening programs for lung cancer improve mortality by 20%

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15 Relative Risk of lung cancer Asbestos exposed, never smoker: No asbestos, smoker: Asbestos exposed, smoker Multiplicative risk Straif, 2009; deklerk, 1991; Reid 2006; Lee, 2001

16 Australian Statistics 5-year survival Lung 8.7% 14% Breast 72% 89% Colorectal 48% 66% Prostate 57% 85% Most lung cancer cases ~80% inoperable at diagnosis Cancer Australia

17 Why low dose CT? Background (Perth) 2-3 msv CXR PA& Lat 0.1 msv Standard CT Chest 5-8 msv PET-CT >10-15 msv LDCT <5 msv Ultra LDCT <1 msv 0.1 to 0.15mSv at PMH and Envision 7 Hour flight 0.02 msv

18 Methods All subjects offered LDCT as part of annual review Prone, no IV contrast Indeterminate nodule volume of at least 50mm 3 semi-solid nodules >5mm Scans read by specialist thoracic radiologist Weekly MDT

19 Characteristics of the cohort Age (mean, SD) 68.8 (9.9) Male 83.4% Smoking status: Current 6.5% Ex 57.2% Never 36.4% Pack years (mean, SD) 17.1 (25) Asbestos exposure Wittenoom worker 16.0% Wittenoom resident 24.3% Other occupational 59.7% Mean time since1 st exposure (years, SD) 50.8 (9.0) Mean exposure duration (months, SD) 149 (175)

20 Results Year 1 Year 2 Total subjects st scan 906 (100%) 115 (11.8%) Indeterminate nodule 79 (8.85%) 42 (4.3%) Recall 77 (8.4%) 37 (3.8%) Lung cancer 7 (0.77%) 3 (0.3%) Mesothelioma 4 (0.44%) 0* All lung cancer cases asymptomatic All year 2 lung cancers are incident cases

21 Lung cancer cases N=10 No symptoms 9 stage 1a (1 stage IIa) Treatment 8 VATS lobectomy 1 stereotactic radiotherapy 1 declining Rx

22 Lung cancer cases Smoking Current 1 Ex 7 Never 2 Asbestos exposure Wittenoom worker 4 Wittenoom resident 3 Other 3

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24 Performance In year 1, 402 participants chose to still have a CXR Using this group as a comparator: Sensitivity 100% Specificity 92% PPV 8.86% False positive rate 91.1%

25 Nodules 58% nodules on the right Site N= LUL 16 Lingula 4 LLL 24 RUL 15 RML 15 RLL 30

26 Incidentals Non-lung cancer Renal carcinoma 2 Gastric cancer 2 Thymoma 1 Colon cancer 1 Mediastinal lymphadenopathy 10 Aortic aneurysm 3

27 Pleural plaques 577 (63.5%) have pleural plaque 512 (56.4%) calcified Visceral 18.3% Diaphragm 77.6% Visceral and parietal 17.1% Majority LML / lingula& RML

28 Is LDCT reliable for asbestosis? 365/906 noted to have evidence of fibrosis 143 subjects have concurrent gas transfer values Manuscript in preparation

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31 Results Malignant mesothelioma: 4 subjects

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33 Conclusions Prevalence lung cancer 0.77% MPM 0.45% Incidence: 0.3% LDCT is effective at detecting early LC Only in a carefully controlled specialist program Lung cancers Asymptomatic, early stage 9/10 had potentially curative therapy

34 Asbestos Review Program Metamorphosed from a research to clinical program Future directions AsbJEM Continue to re-examine dose-response relationships Expanding numbers wider population Participants derive a great deal of comfort from their annual review

35 Asbestos Review Program (ARP) Still recruiting: 3 months regular asbestos exposure +/- pleural plaques Refer potential participants to: [email protected] [email protected]

36 Why not combine the exposure for commercial benefit? Kent asbestos filter cigarettes

37 Questions.

38 20% reduction in lung cancer mortality with LDCT screening 53,454 Participants 55 to 74 years; 30 pack-years Median follow-up 6.5 years NEJM 2011; 365:

39 TSANZ position statement - in preparation The use of CT for uncontrolled ad hoc screening for asymptomatic lung disease is strongly discouraged

40 This is an emerging and very specialist field IASLC working group: Needs specialist MDT Part of a carefully defined project Cost effectiveness needs further evaluation Size vs. volumetric analysis. Smoking cessation Nodule management Field et al, JTO 2012