More Than a Feeling: How Stress Shapes Cancer and Healing – Sami Mansfield

When we think about cancer risk, treatment, and survivorship, the focus is often on visible lifestyle factors – nutrition, exercise, sleep. But there’s a hidden driver that may also influence cancer biology from the inside out: chronic stress.

Stress: Not Just in Your Head – It’s in Your Cells

Chronic stress isn’t just a fleeting feeling. It may actually rewire your body’s chemistry. When your stress response stays “on,” your body ramps up production of hormones like cortisol and adrenaline, sending persistent signals through the HPA axis and the sympathetic nervous system (SNS). These chemical messengers do more than make you feel anxious—they can shift your immune system and may ignite chronic inflammation.

What the Science Says

Scientists have learned that ongoing stress is more than just an emotional burden – it changes the way our bodies work. When we feel stressed for a long time, our bodies turn on systems called the HPA axis and the SNS. These systems are part of how our bodies react to danger. But when they are always active, they may weaken the immune system—the part of our body that fights off general sickness and can be very challenging to someone who is on treatment.

This constant state of stress may also cause more inflammation, which is like the body being on “high alert” all the time. Some research suggests that this kind of stress-related inflammation can actually help cancer grow and spread in the body (He et al., 2023).

Stress also causes the body to release certain chemical messengers, called cytokines, such as IL‑1β, IL‑6, and TNF‑α. These chemicals are supposed to help the body heal from injury or infection, but too many of them can be harmful. When we have too many of these cytokines because of ongoing stress, they may help tumors grow and even spread to other parts of the body (Li et al., 2024).

This isn’t just something that happens in experiments – it’s seen in real life, too. Some studies show that people with cancer who feel more stressed tend to have more side effects during treatment, higher levels of inflammation, a lower quality of life, and sometimes, even a lower chance of survival (Antoni et al., 2012).

Why Does This Happen?

Stress pushes your body into a “fight or flight” state, helpful for emergencies but possibly harmful when constant. Over time, this “always on” signal:

– May lower cancer-fighting immune cells (NK and T-cells)
– May increase tumor-supporting cells and suppressor immune cells
– May boost inflammatory cytokines—creating a microenvironment where cancer can thrive

Why This Matters for Survivors and Care Teams

For those diagnosed with or recovering from cancer, stress isn’t just an emotional hurdle — it may be a modifiable risk factor. Managing stress could mean fewer inflammatory signals, a more resilient immune system, and possibly better treatment outcomes.

Action Steps: Small Shifts, Big Impact

For Survivors

– Practice mindfulness or meditation: Even five minutes daily may help reduce inflammation markers and help regulate stress hormones (Lengacher et al., 2016).

– Move your body: Gentle movement – such as walking, stretching, or “movement snacks” – may help lower stress hormones and support immune health.

– Get outdoors and seek sunshine: Spending time outside, even for a short walk, may boost your mood and help your body’s natural rhythms.

– Prioritize social connection and laughter: Reach out to a friend, join a support group, or simply enjoy a shared laugh. Connection and laughter can help reduce feelings of isolation and stress.

– Try structured breathing: Simple breathwork, like inhaling for 4 seconds, holding for 7, and exhaling for 8, calms the nervous system and may lower markers of inflammation.

– Practice regular gratitude: Take a moment each day to notice something you’re grateful for. Keeping a gratitude journal or simply reflecting on positives may help shift your mindset and lower stress.

For Clinicians

– Initiate the stress conversation: Ask patients how they’re coping. Simple screening and validation go a long way.
– Recommend evidence-based practices: Mindfulness, cognitive behavioral therapy, regular time outdoors, and group support may offer benefits for lowering stress and inflammation.
– Encourage connection and joy: Remind patients that relationships, humor, and gratitude are powerful tools for well-being.
– Connect patients to resources: Share information about support groups, psycho-oncology, stress-management programs, and community wellness opportunities as a routine part of survivorship care.

For Loved Ones

– Offer nonjudgmental support: Sometimes listening, walking together outdoors, or sharing a laugh can be the best medicine.
– Normalize stress management: Encourage regular practices like gratitude, movement, and connection as important—not optional—parts of healing.
– Make time for shared experiences: Whether it’s a walk in the park, time in nature, or enjoying a funny movie together, small joyful moments can help buffer stress.

The Bottom Line

Chronic stress is not just a psychological state; it may be a biological process that can shape cancer outcomes.
Reducing stress is not about perfection – it’s about practice. Even small, daily steps to manage stress may help dial down inflammation, boost immune health, and support healing.

What’s one small thing you can do today to support your body and mind?
Share your practice in the comments – you may inspire someone else’s next step.

References

Antoni, M. H., Lutgendorf, S. K., Cole, S. W., Dhabhar, F. S., Sephton, S. E., McDonald, P. G., … & Sood, A. K. (2012). The influence of bio-behavioural factors on tumour biology: pathways and mechanisms. Nature Reviews Cancer, 6(3), 240–248. https://pubmed.ncbi.nlm.nih.gov/22790082/

He, Y., Li, S., et al. (2023). Interplay between chronic stress and cancer: Focus on inflammation. Frontiers in Immunology, 14, 1196722. https://pubmed.ncbi.nlm.nih.gov/37020461/

Li, Y., et al. (2024). Chronic stress and inflammatory cytokines in cancer: New mechanisms and interventions. Cancer Letters, 589, 216616. https://pubmed.ncbi.nlm.nih.gov/39871957/

Lengacher, C. A., Shelton, M. M., Reich, R. R., Barta, M. K., Johnson-Mallard, V., Moscoso, M. S., … & Kip, K. E. (2016). Mindfulness based stress reduction (MBSR) in post-treatment breast cancer patients: An examination of symptoms and symptom clusters. Journal of Behavioral Medicine, 39(2), 227–241. https://pubmed.ncbi.nlm.nih.gov/26857323/

Written by Sami Mansfield

Sami Mansfield is an exercise oncology and lifestyle medicine consultant with endless curiosity and persistence. As the founder of Cancer Wellness for Life, Sami Mansfield has dedicated her career to empowering cancer survivors and clinicians through innovative, evidence-based programs that improve health outcomes while optimizing cost-efficiency.

Sami is a contributing author to groundbreaking guidelines, including the ASCO Guidelines on Exercise, Nutrition, and Weight Management, and has helped shape numerous state cancer control plans.

Sami Mansfield is the current chair of the Cancer Member Interest Group for the American College of Lifestyle Medicine, where she drives forward initiatives emphasizing the connection between science and implementation. Her patient-facing programs like BUILD and My Lifestyle Shift have reached global audiences, transforming lives through the pillars of lifestyle medicine.

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