When a firefighter is diagnosed with cancer, the community rallies. There are fundraisers, meal trains, time-off donations, and an outpouring of support through treatment. And when that firefighter reaches remission — when the scans come back clear and the oncology team says the treatment worked — there’s often celebration. The worst is over. Time to get back to life.
Except for many firefighters, remission isn’t the end of the health battle. It’s the beginning of a different one.
Cancer-related fatigue (CRF) is one of the most common, most persistent, and most underappreciated consequences of cancer treatment. It’s not the kind of tired that sleep fixes. It’s a bone-deep, function-impairing exhaustion that can last for months or years after the last round of chemotherapy — and that affects virtually every dimension of a person’s life, including, crucially, their ability to do their job.
For firefighters, whose job demands extraordinary physical and cognitive performance under acute stress, that last part matters enormously. A new research project from the University of North Carolina at Chapel Hill’s Ryan Lab Group, funded by the National Institute for Occupational Safety and Health (NIOSH), is studying this intersection directly: how does cancer-related fatigue affect firefighters in remission, and what can be done about it? The research is currently recruiting participants, and the insights it generates could meaningfully change how the fire service supports its cancer survivors.
Why Firefighters and Cancer Are Inseparable Conversations
To understand why this research matters, you first need to understand the scale of the cancer problem in the fire service.
In 2022, the International Agency for Research on Cancer (IARC) — the global authority on carcinogen classification — made it official: occupational exposure as a firefighter is carcinogenic to humans. That’s a Group 1 classification, the same category as asbestos and tobacco smoke. The decision was based on sufficient evidence that firefighting causes mesothelioma and bladder cancer, with limited evidence for several additional cancer types including colon, prostate, and testicular cancers, as well as melanoma and non-Hodgkin lymphoma.
The biological mechanism is not mysterious. Every structure fire releases a toxic cocktail of combustion byproducts — polycyclic aromatic hydrocarbons (PAHs), benzene, formaldehyde, asbestos from older buildings, diesel exhaust from apparatus, and dozens of other known or probable carcinogens. These chemicals are absorbed through the skin, inhaled through gaps in respiratory protection, and carried home on gear and clothing. Firefighters are also exposed to PFAS chemicals from the aqueous film-forming foam (AFFF) used in fire suppression — a class of compounds now linked to several cancers.
| >60% Of firefighter line-of-duty deaths attributed to occupational cancer | +9% More cancer diagnoses in career firefighters vs. the general population (NIOSH study, 30,000 firefighters) | Group 1 IARC carcinogen classification for occupational firefighter exposure (2022) | +58% Elevated mesothelioma risk in career firefighters vs. general population (meta-analysis) |
Cancer has overtaken cardiac events as the leading cause of firefighter line-of-duty deaths. More than 60% of firefighter line-of-duty fatalities are now attributed to occupational cancer. The fire service is living through a cancer crisis — and increasingly, that means it is also living through a cancer survivorship crisis, as more firefighters reach remission and try to return to work and life.
What Is Cancer-Related Fatigue — and Why Is It Different From Just Being Tired?
The clinical definition of cancer-related fatigue (CRF) is precise for a reason: this isn’t ordinary tiredness, and conflating the two leads to undertreated patients and misunderstood symptoms.
CRF is formally defined as a distressing, persistent, subjective sense of physical, emotional, or cognitive tiredness or exhaustion related to cancer or cancer treatment — one that is not proportional to recent activity and that interferes with usual functioning. The critical distinguishing feature is that it does not resolve with rest or sleep. A person with CRF can sleep 10 hours and wake up just as exhausted as before.
| Ordinary Fatigue Caused by exertion or lack of sleep. Resolves predictably with rest. Proportional to activity level. Does not impair baseline functioning when rested. | Cancer-Related Fatigue (CRF) Persists regardless of rest or sleep. Disproportionate to activity level. Affects physical, cognitive, and emotional function simultaneously. Can last months or years post-treatment. |
The underlying biology of CRF is multifactorial and not fully understood, but research points to several intersecting mechanisms. Cancer treatment — particularly chemotherapy and radiation — can trigger chronic low-grade inflammation via cytokine dysregulation. Survivors with CRF consistently show elevated levels of pro-inflammatory cytokines compared to non-fatigued survivors. Treatment also disrupts sleep architecture, disrupts circadian rhythms, causes hormonal changes, and can impair muscle energy metabolism in ways that outlast the treatment itself. The result is a biological state where the body hasn’t fully recalibrated even though treatment is done.
“Being fatigued has a greater negative impact on functioning and health-related quality of life than other symptoms such as pain or depression. Fatigued survivors are more likely to have reduced employment participation, greater financial stress, and higher healthcare utilization.”
— Current Treatment Options in Oncology, review of cancer-related fatigue causes and treatment
How Common Is CRF Among Cancer Survivors?
The numbers are striking. A 2023 meta-analysis drawing on data from over 34,000 cancer patients found that 43% of survivors experience clinically significant CRF — with the prevalence rising to 70.7% when mild fatigue is included. Among survivors who are still working — the population most relevant to the firefighter study — a separate 2025 meta-analysis of 18 studies found that 42.2% of employed cancer survivors experience CRF, with fatigue severity significantly higher than workers without a cancer history.
The persistence is what makes CRF such a serious problem. This isn’t a temporary side effect that clears up in a few weeks. Research shows that more than 20% of cancer survivors still report moderately severe fatigue 12 months after treatment ends. Studies tracking survivors five years out continue to find high prevalence — in some populations, fatigue is reported by the majority of survivors at five-year follow-up. One large prospective population study published in 2025 found that approximately one-third of long-term survivors reported affective, cognitive, or physical fatigue — and that fatigue was associated with increased all-cause mortality.
Despite this, CRF remains significantly underdiagnosed and undertreated. Research consistently finds that up to 50% of survivors report not receiving help for CRF from their healthcare providers, even when they experience it significantly. The condition lacks a simple biomarker, which means it depends on patient-reported symptoms — and patients are often reluctant to bring it up, or are told that fatigue is simply part of recovery and will resolve on its own.
The Firefighter-Specific Problem: When Your Job Requires Everything You Have
CRF is a serious challenge for any working adult trying to return to their career after cancer treatment. But for firefighters, the stakes are uniquely elevated — because the physical and cognitive demands of firefighting are not just high, they’re life-or-death.
Structural firefighting requires sustained aerobic capacity, muscular strength and endurance, heat tolerance, and the ability to make rapid decisions under extreme sensory and emotional stress. A firefighter at a working structure fire may be wearing 50+ pounds of gear, climbing stairs, pulling hose, and forcing doors — all while operating in low-visibility, high-heat conditions where errors kill people. There is no low-intensity version of interior fire suppression.
Now consider that cancer-related fatigue specifically impairs the domains that firefighting most depends on:
How CRF Intersects With Firefighter Job Demands
- Physical stamina:CRF reduces aerobic capacity and muscular endurance — the exact physical resources consumed during fire suppression and rescue operations
- Cognitive performance:CRF impairs concentration, decision-making speed, and working memory — critical functions during incident command and rapid tactical assessment
- Emotional regulation:CRF amplifies mood disturbance and reduces stress tolerance — compounding the psychological demands already inherent to emergency response
- Heat tolerance:Treatment-related physiological changes may reduce heat stress resilience — a significant safety concern at structure fires
- Sleep and recovery:CRF disrupts sleep quality, impacting shift-work readiness and recovery between demanding operational periods
The question of when a firefighter is safe to return to full duty after cancer treatment isn’t just a medical question — it’s a safety question for their crew and the public. And yet, there is currently almost no research specifically examining how CRF manifests in firefighter cancer survivors, how it affects their operational readiness, or what interventions might help them return to peak performance.
That gap is precisely what the UNC Ryan Lab Group study aims to close.
The UNC Research Study: What They’re Trying to Find Out
The research project, housed in UNC Chapel Hill’s Motion Science Institute and funded through NIOSH’s North Carolina Occupational Safety and Health Education and Research Center, is led by the Ryan Lab Group — a research team with an established focus on firefighter health and wellness, including prior studies on exercise interventions for firefighters and performance fatigability.
The current study is a survey-based investigation asking a foundational question: what is the prevalence and severity of cancer-related fatigue among U.S. firefighters who are currently in remission? The survey covers cancer history, fatigue symptoms, current health status and behaviors, and work history.
It sounds straightforward — but this kind of foundational prevalence data doesn’t currently exist in any systematic form for the firefighter population. We know CRF is common among cancer survivors generally. We know firefighters have elevated cancer rates. But we don’t know how many firefighter cancer survivors are currently struggling with CRF, how severely it’s affecting them, or how it maps onto their ability to perform their jobs.
The study is open to current or retired U.S. structural firefighters who have received a cancer diagnosis, completed treatment, and are currently in remission. It takes approximately 15 minutes and is fully anonymous. Participants can opt into a drawing for one of 10 gift cards as compensation.
“The overall objective of this project is to better understand the experiences of firefighters who have had cancer by assessing the presence and severity of CRF of firefighters in remission following cancer treatment.”
— UNC Ryan Lab Group, project description
Importantly, this study is part of a broader research arc. A related study from the same lab group — titled “Contributors of Performance Fatigability Among Firefighters in Cancer Remission” — is examining the physical mechanisms behind fatigue in this population, looking at how treatment affects actual performance capacity, not just subjective symptoms. Together, these projects represent the beginning of a systematic evidence base for firefighter cancer survivorship care.
What the Evidence Already Suggests About Managing CRF
While the UNC study is gathering new data specific to firefighters, the broader science on CRF management offers some directions that are relevant here.
Exercise Is the Best Tool We Have
Across multiple meta-analyses and randomized trials, exercise — particularly a combination of aerobic and resistance training — has consistently demonstrated the strongest evidence base for reducing CRF among cancer survivors. The American College of Sports Medicine’s updated cancer exercise guidelines report strong evidence for exercise improving both CRF and self-perceived physical function. Guidelines generally recommend at least 150 minutes per week of moderate aerobic exercise plus twice-weekly resistance training for cancer survivors.
For firefighters, this matters beyond general wellness: the physical demands of the job already require a baseline fitness level that must be maintained or rebuilt post-treatment. A well-designed exercise-based rehabilitation pathway for firefighter cancer survivors could address CRF management and return-to-duty fitness simultaneously.
CRF Is Underreported and Undertreated in Occupational Settings
The evidence that CRF is significantly underaddressed — with half of survivors reporting they never received help for it — points to a systemic communication gap. In the fire service, the culture of toughness and stoicism that serves firefighters in high-stress operations can actively work against them when it comes to reporting ongoing health symptoms during recovery. Research on this specific dynamic in the fire service doesn’t yet exist — which is another reason the UNC survey data will be valuable.
Fatigue Has Real Occupational Safety Implications
A 2024 meta-analysis in the Journal of Cancer Survivorship found that among currently employed cancer survivors, fatigue severity was significantly higher than in workers without cancer, and that the presence of distress and fatigue together predicted reduced work capacity. For safety-sensitive occupations like firefighting, elevated fatigue in a returning worker isn’t just a personal health issue — it’s an operational risk that departments need protocols to assess and manage.
What Fire Departments and Occupational Health Programs Need to Be Asking
The UNC research also raises a broader challenge for fire departments and the occupational health systems that support them: the current model of return-to-duty clearance after cancer treatment is typically binary. A firefighter is either cleared or not cleared for full duty. What the CRF literature suggests is that the reality is more complex — a firefighter can be in remission, cleared by their oncologist, and still experiencing fatigue that meaningfully impairs their performance and safety on the fireground.
A Gap in Current Return-to-Duty Protocols
Standard return-to-duty clearance after cancer treatment focuses on disease status — is the cancer in remission? But cancer-related fatigue is a distinct, often invisible condition that can persist after remission is achieved. Fire departments and occupational health programs may need tools to assess CRF specifically as part of fitness-for-duty evaluations in returning cancer survivors — separate from the question of whether the cancer itself is resolved.
This is where comprehensive occupational health screening programs — like those UDS Health provides for fire departments and first responder organizations — have an important role to play. Identifying cancer early is the first priority. But supporting firefighters through the survivorship phase — including monitoring for CRF, tracking return-to-duty readiness, and connecting survivors to evidence-based interventions — is the next frontier of first responder health.
Cancer survivorship care for firefighters isn’t just a medical issue. It’s a workforce sustainability issue. The fire service has invested heavily in training and retaining experienced firefighters. Losing a firefighter to early retirement because post-treatment fatigue wasn’t recognized and managed is a preventable outcome — one that good occupational health systems can address.
How to Support the Research — and Why It Matters
The UNC Ryan Lab Group study is currently open for participation. If you are a current or retired structural firefighter who has received a cancer diagnosis, completed treatment, and is in remission, your participation matters.
The data this study generates will inform future interventions — exercise programs, occupational health protocols, peer support structures — designed specifically for firefighter cancer survivors experiencing CRF. Fourteen data points from a 15-minute anonymous survey could, in aggregate, help the next generation of firefighters who survive cancer also return to doing the work they love.
The fire service has fought hard to have firefighter cancer recognized as an occupational disease, to expand presumption laws, and to build awareness of cancer prevention. The next chapter of that fight is about what happens after the diagnosis — making sure that remission is genuinely a return to health, not just an absence of active disease.
Research like this is how that chapter gets written. For more information about early detection and occupational health programs for first responders, or to learn how comprehensive health screening can reduce cancer risk in your department, reach out to UDS Health.
Sources: Ryan Lab Group, UNC Chapel Hill. “The Impact of Cancer-Related Fatigue Among Firefighters in Cancer Remission.” NIOSH-funded (T42OH008673) | IARC Monographs Volume 132: Occupational Exposure as a Firefighter (2022) | Matsunaga M, et al. “Prevalence, severity, and risk factors of CRF among working cancer survivors.” J Cancer Survivorship, 2025 | Dana-Farber / ACS firefighter cancer mortality studies (2025–2026) | NIOSH National Firefighter Cancer Study | American Cancer Society firefighter cancer risk data
