1. Summary of Fire Fighter Cancer Cohort Studies
Patrick Morrison
IAFF Assistant to the General President for Health, Safety and Medicine

2. Overall Cancer Risk
Cancer is the second leading cause of death in the United States (after heart disease)
Cancer takes years to develop (latency)
Multiple factors affect risk for developing cancer
Smoking, diet, genetics/family history, occupational & environmental exposures

3. Connecting Exposure to Cancer
International Agency for Research on Cancer (IARC)
Known human carcinogens (Group 1)
How do we determine if occupational exposures result in an increased risk for developing cancer in fire fighters?

4. Relevant Research Approaches
Animal exposure studies
Human epidemiology studies
Cancer in fire fighters
Cohort studies
Similar exposures or fire fighter occupation in patients with specific types of cancer
Case-control studies

5. Relevant Epidemiologic Studies
Meta-analysis
Research technique combining multiple studies
Increased power to detect risk with more participants
Quality, consistency of data
LeMasters
Combined data in 32 studies of fire fighters for 20 different cancer types
Risks for 10 types of cancer (50%) were significantly increased
Risks for the other 10 were increased although not significant
LeMasters et al. JOEM, 2006

6. NIOSH Fire Fighter Cancer Study
US National Institute for Occupational Safety and Health (NIOSH)
One of the largest studies of US fire fighters
~30,000 career fire fighters
Chicago, Philadelphia, and San Francisco
Employed between 1950 and 2009
Non-white and female fire fighters included

7. NIOSH Study Phase I
Compared cancer deaths and diagnoses in fire fighters to general public
Control for age, sex, race and calendar-time
Results
4461 cancer diagnoses, 3285 deaths
Increase in cancer rates overall (death and diagnosis)
Significant increases for gastrointestinal, genitourinary and lung cancers
Daniels et al., Occ Env Med. 2013

8. Actual Risk of Cancer in Fire Fighters
Many news articles claim fire fighters have a 68% risk of cancer compared to 22% in the general public and reference the NIOSH study
Of 29,993 fire fighters in the NIOSH study
3285 (11%) died from cancer compared to 2882 (9.6%) expected based on age, race and sex
14% higher risk (3285/2882); 403 more deaths
4461 (14.9%) were diagnosed with cancer compared to 4093 (13.6%) expected
9% higher risk; 368 more diagnoses
Firefighter Cancer Support Network: bit.ly/FCSNfactFB

9. NIOSH Study Phase 2: Exposure
Detailed work histories of position(s) each fire fighter held and the length of time in the position
Very challenging
Cumulative number of fire runs, exposed days, fire run-hours
Lack of data on use of personal protective equipment and diesel exhaust controls
Compare cancer risk in higher exposed fire fighter compared to lower exposed
Lung cancer and leukemia risk increased with exposure
Colon and prostate cancer risk decreased
Daniels et al., Occ Env Med. 2015

10. Nordic Study
Cohort study of cancer incidence (diagnosis) in 16,422 fire fighters from five Nordic countries
National cancer registries linked to census data on occupation from
Increased risk for all cancers combined
Statistically significant increases in specific cancers
Melanoma and non-melanoma skin cancer, lung and prostate cancer
In specific ages: mesothelioma and multiple myeloma in 70+ year olds
Did not observe change in prostate cancer risk after screening started
Pukkala, et al. Occ Env Med. 2014

11. Australian Study
Cancer mortality and incidence in 17,394 full-time fire fighters followed from
Excess risk of diagnosis for all cancers, prostate and melanoma
Less risk of lung cancer (authors attributed to less smoking)
Internal exposure analyses for years as fire fighter and # fires
Kidney and prostate cancer and non-Hodgkin lymphoma associated with longer service
Prostate cancer also associated with increased attendance at fires
Melanoma not associated with longer service but also not increased in fire fighters from sunniest study location
Glass, et al. Occ Env Med 2016

12. Other Studies Cohort studies Case-control
Danish, French, Korean, Scottish, Swedish
Case-control
California cancer registry

13. Which Cancers Are Work-related in Fire Fighters?
Meta-analysis
UK IOM
Study quality
Consider consistency across studies

14. Cancers listed if significant in ≥ 2 studies
Significant overall or in *specific age group; A=Australia, C=California, K=Korea;
Cancers listed if significant in ≥ 2 studies

15. Challenges in Epidemiologic Studies in Fire Fighters
Exposure misclassification
Healthy worker effect
Australian study as example
All cause death = 0.67
Small population sizes
Underestimation of true risk
All cause death = 0.67 (CI = )

16. Challenges in Epidemiologic Studies in Fire Fighters
Lack of data on other cancer risk factors
Smoking, family history, diet, weight, other exposures
Significance of effect size
Risk of lung cancer from environmental tobacco smoke is ~ 1.25
Vineis P et al. Environmental Health. 2009

17. US Cancer Mortality Progress
Death rate dropped 26% from 1991 to 2015
~ 2,378,600 fewer cancer deaths than if rates continued at 1991 level
Remains second leading cause of death
609,640 cancer deaths estimated in 2018
Siegel/American Cancer Society. CA Cancer J Clin 2018.

18. American Society of Clinical Oncology’s National Cancer Opinion Survey: 4,016 adults in July, 2017

19. Selected Cancer Types by Risk Factor*
Obesity
Uterine, breast, kidney, liver, pancreatic, and colorectal
Alcohol
Breast, mouth/throat, and colorectal
Human papilloma virus
Cervical, anal, and oropharyngeal
Smokeless tobacco
Mouth, esophageal, pancreatic
*Listed by estimated number of cancers caused; Islami et al. CA Cancer J Clin. 2018;

20. Unvalidated Cancer Screening Tests
Does the test reduce death or illness from the cancer when used in asymptomatic populations (compared to standard screening if applicable)?
Risk not from test but from response to the test
DermSpectra
Thyroid scan
Blood tests: ONCOblot, IvyGene, BreastSentry, Guardant360, thymidine kinase 1
Canine scent detection (cancer sniffing dogs)
Whole body imaging: ultrasound, CT

21. IAFF Recommendations
Efforts to reduce both occupational and non-occupational risk factors
Established cancer screening tests
Wellness-Fitness Initiative
Cancer Awareness Course
WFI screening based on general population recommendations of authoritative organizations (American Cancer Society (ACS), US Preventive Services Task Force, American Heart Association) modified to reflect increased risk in fire fighters

22. Summary of Fire Fighter Cancer Cohort Studies
Patrick Morrison
IAFF Assistant to the General President for Health, Safety and Medicine