Cross-Sectional Evaluation of Self-Reported Cancer
Abstract
EMS professionals are often on the scene of fires and other chemical exposures, but have less personal protective equipment than firefighters. Thus, EMS professionals have the potential for increased cancer risk, but little is known about cancers that affect them. Our objective was to describe the most common cancers affecting EMS professionals.
This study was a cross-sectional analysis of a survey of nationally-certified EMS professionals. After recertifying their National EMS certification, participants were invited to complete a survey with questions regarding demographics, work experience as a firefighter, cancer diagnosis and type and age at cancer diagnosis. Descriptive statistics were used to describe cancer type by firefighter status and cancer diagnosed before and after starting EMS careers.
Related
- Elevated Leukemia Incidence Found in World Trade Center Rescue and Recovery Workers
- 15-40 Partners with FDNY on Early Cancer Detection
A total of 22,678 individuals met inclusion criteria (response rate=26%). The mean age (SD) was 39.3 (11.7) with 72.8% male. Among EMS professionals, 38.5% (n=8,733) were never firefighters. Approximately 5.1% (n=1,165) reported ever having cancer. Reporting ever having cancer differed by firefighter status (p=0.002) with ever firefighters reporting higher prevalence of cancer than never firefighters (6.7% v 5.1%). The most commonly reported cancers prior to starting in EMS were skin (any type) (42.2%), cervix/cervical (10.2%), and thyroid (6.0%).
After starting in EMS, the most common cancers were skin (any type) (52.4%), prostate (6.4%), and thyroid (4.7%). EMS professionals are afflicted by several different cancers, including those common in younger populations. Future work should investigate potential common carcinogenic exposures that EMS professionals may encounter, and cancer prevention strategies targeted to EMS professionals.
Introduction
In 2017, an estimated 15,760,939 people were living with cancer, which equates to approximately 4.8% of the total United States population.1 Cancer has many causes including genetic components, lifestyle factors and occupational exposures. The International Agency for Cancer Research has recognized that occupational causes of cancer contribute to the overall burden of cancer incidence and mortality.2 Estimates for the occupational burden of cancer vary and depend on the occupation and hazards at the workplace.3, 4
The overwhelming burden of occupational cancer stem from respiratory inhalation and dermal contact.2 Emergency response personnel including firefighters, police and emergency medical service (EMS) professionals, are often exposed to several occupational hazards and carcinogens due to exposure to structure fires as well as other man-made disaster and natural disasters. It is widely recognized now that firefighters have an increased risk for cancer including malignancies of the colon, rectum, prostate, testis, bladder, thyroid, pleura and malignant melanoma.5
While extensive evidence is available for an elevated risk for cancer (including colon, prostate, testis, bladder, thyroid, pleura, and malignant melanoma) among firefighters,5 less attention has been paid to EMS professionals not working in the fire service. EMS professionals represent a large workforce and include an estimated 262,100 people in 2018 with the number of people in this occupation expected to grow over the next 10 years.6
EMS professionals are often involved in fireground operations with firefighters but may not have access to the same respiratory protection equipment as firefighters. EMS professionals also provide direct patient care which may lead to exposure of potential oncogenic viruses such as hepatitis B and hepatitis C viruses. Therefore, EMS professionals may be exposed to multiple risk factors for cancer. Limited evidence suggests that EMS professionals are at increased risk for cancer mortality, but this evidence stems from a single study.7 Therefore, EMS professionals remain an understudied occupational population in cancer research.
With a growing workforce over the next ten years ,6 it is important to understand the unique occupational risks for cancer that may be present in EMS professionals. The first step in understanding if EMS providers have an evaluated risk for cancer is to describe the major types of cancer that afflict the EMS workforce. Therefore, the study provides a preliminary report of cancer among EMS professionals using self-reported cancer diagnosis among a national sample of EMS professionals.
Material and Methods
Data. The study utilized data collected from EMS professionals recertifying their national certification from October 1st, 2017, to March 31st, 2018, through the National Registry of Emergency Medical Technicians (NREMT). The study examined the frequency of the top ten reported cancers that occurred before and after starting as an EMS provider. After completing their national recertification, participants were invited to complete an electronic questionnaire.
The questionnaire included questions regarding demographics, workforce profile, work experience, cancer diagnosis and cancer type. The study included only participants who were between the ages of 18 to 85 years old and currently working providing patient care as an emergency medical technician (EMT) or higher (advanced EMT or paramedic). The study had a response rate of approximately 26% (n=22,678).
Variables. To determine cancer diagnosis, the survey asked participants, “Have you ever been told by a doctor or other health professional that you had cancer or a malignancy of any kind?” and if yes, “What kind of cancer was it?” Cancer types were classified by major organs including: bladder, blood, bone, brain, breast, cervix/cervical, colon, esophagus, gallbladder, kidney, larynx, leukemia, liver, lung, lymphoma/Hodgkin’s, melanoma, mouth/tongue/lip, nervous system, ovary, pancreas, prostate, rectum, skin (non-melanoma), skin (don’t know what kind), soft tissue, stomach, testicular, thyroid, uterus, other, more than three kinds, and don’t know.
The study combined all three skin cancer options (melanoma, non-melanoma, and skin [don’t know what kind]) into a single category. The survey then asked the age at which they were diagnosed with cancer. The study categorized their cancer diagnosis into two groups: (1) before and (2) after starting as an EMS provider based on the age they started as a provider. Data were unavailable about cancer diagnosed after leaving the EMS profession.
Because an estimated 40% of EMS agencies are based in fire departments, there is a high probability of cross-over between EMS professionals and firefighters, in terms of occupation and working conditions (i.e. being on the scene of fires). Since it is known that firefighters are at a greater risk for cancer, the study evaluated the difference in cancer prevalence by self-reported firefighter status.
Specifically, the study inquired about previous or current firefighter work. The study then categorized participants into three categories: never been a firefighter, ever been a firefighter and currently a firefighter. Due to small sample size concerns, the study could not evaluate specific cancer types by firefighter status.
Statistical Analysis. The study obtained basic descriptive statistics including means and frequency distributions. The study also utilized Chi squared test (α=0.05) to test for differences in cancer diagnosis by firefighter status. All analysis occurred in STATA version 16 (StataCorp, College Station, TX).
Ethical approval. This study was approved by the Institutional Review Board at the American Institutes for Research. Informed consent was obtained.
Results
Respondent characteristics. On average respondents were young and a majority were white (n=19,391; 85.5%) and male (n=16,643; 72.6%) similar to the larger EMS population (Table 1). Most respondents were either certified at the EMT level (n=10,227; 45.1%) or the paramedic level (n=11,419; 50.3%). Only 18.8% of respondents (n=8,733) indicated that they never have been a firefighter.
Table 1. Demographic characteristics of a national sample of EMS professionals recertifying their national certification from October 2017 to March 2018 (n=22,678)
| Characteristic | Mean | SD |
| Age | 39.3 | 11.7 |
| N | % | |
| Sex | ||
| Male | 16,643 | 72.6 |
| Female | 6,140 | 27.1 |
| Missing | 75 | 0.3 |
| Race | ||
| White | 19,391 | 85.5 |
| Non-White | 2,691 | 11.9 |
| Missing | 596 | 2.6 |
| Education | ||
| Less than High School | 15 | 0.1 |
| High School/GED | 3,089 | 13.6 |
| Some College | 6,856 | 30.2 |
| Associates | 5,099 | 22.5 |
| Bachelors | 5,818 | 25.7 |
| Masters | 1,593 | 7.0 |
| Doctoral | 190 | 0.8 |
| Missing | 18 | 0.1 |
| Certification level | ||
| EMT | 10,227 | 45.1 |
| AEMT | 1,032 | 4.6 |
| Paramedic | 11,419 | 50.3 |
| Job status | ||
| Full time | 15,078 | 66.5 |
| Part time | 5,456 | 24.1 |
| Missing | 2,144 | 9.4 |
| Firefighter status | ||
| Current Firefighter | 7734 | 34.1 |
| Ever a Firefighter | 4261 | 18.8 |
| Never a Firefighter | 8733 | 38.5 |
| Missing | 1950 | 8.6 |
| Ever been told they have cancer | ||
| Yes | 1165 | 5.1 |
| No | 19060 | 84.1 |
| Missing | 2453 | 10.8 |
| Total cancer reported | 1304 | 100 |
| Cancer reported prior to starting EMS career | 586 | 44.9 |
| Cancers reported during EMS career | 718 | 55.1 |
Approximately 5% of respondents (n=1,165) indicated that they had cancer at some point during their lifetime. These 1,165 reported approximately 1,304 incident cancers with some individuals reporting more than a single cancer. Among the 1,304 reported incidences of cancer, 55.1% (n=718) occurred while the respondent was employed as an EMS provider.
Cancer prior to EMS career. Of the 586 cancers reported prior to starting work as an EMS provider (44.9% of all cancers reported), skin cancer of any type (n=247; 42.2%) was the most commonly reported cancer (Table 2). Additionally, cervix/cervical (n=60; 10.2%), thyroid (n=35; 6.0%), prostate (n=30; 5.1%), and lymphoma/Hodgkin’s lymphoma (n=29; 4.9%) were the top five most commonly reported cancers prior to starting as an EMS provider.
Table 2. Top ten most common cancers diagnosed prior to starting and during EMS career reported by EMS professionals recertifying from October 2017 to March 2018
| Diagnosed prior to starting EMS career | ||
| Cancer Type | n | % |
| Skin 1 | 247 | 42.2% |
| Cervix / Cervical | 60 | 10.2% |
| Thyroid | 35 | 6.0% |
| Prostate | 30 | 5.1% |
| Lymphoma/Hodgkin’s | 29 | 4.9% |
| Breast | 24 | 4.1% |
| Testicular | 20 | 3.4% |
| Other | 19 | 3.2% |
| Ovary | 17 | 2.9% |
| Colon | 16 | 2.7% |
| Diagnosed during EMS career | ||
| Cancer Type | n | % |
| Skin 1 | 376 | 52.4% |
| Prostate | 46 | 6.4% |
| Thyroid | 34 | 4.7% |
| Breast | 30 | 4.2% |
| Cervix/cervical | 30 | 4.2% |
| Colon | 24 | 3.3% |
| Testicular | 20 | 2.8% |
| Kidney | 19 | 2.6% |
| Lymphoma/Hodgkin’s | 19 | 2.6% |
| Uterus | 17 | 2.4% |
Cancer during EMS career. Of the 718 cancers reported after starting work as an EMS provider (55.1% of all cancers reported), skin cancer of any type (n=376; 52.4%) was still the most common type of cancer reported (Table 2). Respondents reported more prostate (n=46; 6.4%), breast (n=30; 4.2%), colon (n=24; 3.3%), kidney (n=19, 2.6%) and uterus (n=17; 2.4%) cancers during their EMS career than prior to starting as an EMS provider. Additionally, respondents reported fewer cases of cervix/cervical cancer (n=30; 4.2%) or lymphoma/Hodgkin’s lymphoma (n=19; 2.6%) during their EMS career.
Cancers by firefighter status. Examining cancer by firefighter status revealed that individuals who reported ever being a firefighter had the highest prevalence of cancer (n=91.2; 6.7%) (Table 3). Furthermore, current firefighters (n=423; 5.5%) also had a higher prevalence of cancer when compared to those who never had been a firefighter (n=448; 5.1%). The association between cancer prevalence and firefighter status was statistically significant (X2=12.9 df=2 p-value=0.002)
Table 3. All cancers diagnosed by firefighter status reported by EMS professionals recertifying from October 2017 to March 2018
Discussion
Among all respondents, a little over 5% reported ever having cancer, which is slightly higher than the estimated national prevalence of cancer (4.8%).1 However, respondents who were either current (5.5%) or previous firefighters (6.7%) reported a higher prevalence of cancer compared to respondents who had never been a firefighter (5.1%). While respondents who ever reported working as firefighters had a prevalence of cancer when compared to only EMS professionals, EMS professionals still had a higher prevalence of cancer than the national average.
EMS professionals reported a myriad of cancer types including those primarily observed in younger populations (skin, breast, testis, and cervical cancers).8 Unfortunately, this study was unable to assess lifestyle factors (i.e. smoking, alcohol use, etc.), genetic factors or occupational exposures that may have led to these cancers.
Little is known about cancer risk among EMS professionals. However, what limited evidence does exist points to an increased risk for cancer. In a study conducted in the 1970s among healthcare providers in England and Wales, Balarajan (1989), noted several inequalities in health between different healthcare providers.7
Balarajan was seeking to evaluate health inequities by social class in male healthcare providers and notes that EMS professionals (called ambulance men in their study) had a statistically higher standard mortality ratio for dying of all cancers when compared to the general public.7 It is possible that this higher standardized mortality ratio also indicates a higher incidence of cancer. Our findings do appear to support the hypothesis of a greater cancer prevalence in EMS than the general population.
Other evidence to support a potential increase in cancer risk come from man-made disasters such as the terrorist attack on the World Trade Center in New York City. It is widely recognized that first responders working at the World Trade Center disaster site report a higher incidence of cancer and cancer mortality than the general public.9-11 During this event, and subsequent rescue and clean up, thousands of first responders were exposed to particulates that became airborne and to smoke from fires that burned until December of 2001.12
However, this event is not typical of an EMS professional’s normal routine, but EMS professionals may be exposed to similar carcinogens on a much smaller scale when they respond to fires and other smaller scale disasters. The accumulation of these exposures could lead to an increased cancer risk. Again, our results support an increased risk for cancer including those that could be linked to dermal contact (i.e. skin cancer) or inhalation (i.e. lymphomas and kidney cancer).
Our findings are not without limitations. First and foremost, our findings are likely biased due to healthy worker effect in which the study may be missing the more severe cases of cancer due to ill individuals leaving the workforce. Therefore, it is probable that the study is underreporting the true number of cancer cases. Next, the study relies on self-reported cancer diagnosis. While individuals are unlikely to misreport having cancer, they may misreport the type of cancer or the age of diagnosis.
However, an evaluation of self-reported cancer status found good agreement with a state cancer registry in a similar population,13 so the bias from self-report may not be as large as previously thought. Third, the study lacked detailed clinical information about the cancers that respondents reported including items like stage, grade, and treatment. The study also lacked data on lifestyle factors that increase risk for cancer as well as family history of cancer. However, because this was an initial descriptive study, this information can be collected better with a more rigorous study design such as a case-control study or a longitudinal study.
Additionally, the participants evaluated were only nationally registered EMS providers; due to different credentialing among states those with only state licensure not requiring a national certification to practice were not captured. The study also had a low response rate to the survey which could lead to potential response bias in these results. Finally, the study is unable to completely parse out firefighter and EMS provider occupations.
While the study demonstrated that current and former firefighters have a higher prevalence of cancer than respondents who were solely EMS professionals, the study is unable to examine the time of exposure to carcinogens. Future studies will need to directly address these issues in the future.
The study noted that EMS professionals suffer from various cancers including those that affect younger populations. Our analysis is the first step in identifying a potential occupation with an increased risk for cancer that has not previously been investigated. These steps include evaluating potential exposures sources and pathways and specific cancer types using longitudinal data collection and analysis.
Disclaimers
The authors declare no conflicts of interest.
Sources of Support
The authors report that there was no funding source for the work that resulted in the article or the preparation of the article.
Funding
The authors report that there was no funding source for the work that resulted in the article or the preparation of the article. The authors declare no conflicts of interest.
Authors’ Contributions
RBH contributed to the analysis, data interpretation and wrote the manuscript. REC, KC and ARP contributed to the design of the study, data collection, data interpretation, and revising the manuscript. MKR and CM contributed to the data interpretation and revising the manuscript. All authors approved the final manuscript and agreed to be accountable for all aspects of the work.
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