Can Stress Lead to Cancer?

How Much Is Hype?

Stressed man at work
Milton Brown/Getty Images

We know that stress is not good for us. Especially the day-in, day-out survival-type stress that persists over weeks, months, and years, which is also known as chronic psychological stress. But can it really have that much of an impact on us? Enough of an impact to increase our risk for very specific illnesses and even cancers? The answer appears to be yes for some illnesses, but there isn't always a clear answer when it comes to cancer and its development.

Effects of Psychological Stress

While some stress is the good stress that keeps us motivated and prevents us from boredom, there is another type of stress that appears to be more pernicious.

According to the National Cancer Institute (NCI), psychological stress is what people feel when they are under mental, physical, or emotional pressure. And there is evidence that people who have high levels of psychological stress in their lives, or who experience stress frequently over a long period of time, may be at risk for developing a variety of health problems, including cancer. However, at least with respect to cancer, there are many unknowns.

Effects of Employment Stress

A group of researchers at the University of Montreal in Canada focused on the association between perceived workplace psychological stress and cancer. They set out study the relationship between work-related stress over an entire career span, and the development of cancer—something that had never been done before.

Findings were striking, although the study was not designed to allow for any solid conclusions regarding cause and effect.

For the study, researchers interviewed 3,103 men who were diagnosed with one of 11 cancer types between 1979 and 1985. In another group, they had interviews from 512 men in the general population who served as the study’s controls.

All of the men included for study were asked to describe each job they worked during their lifetime, with attention to work-related stress and the reason why they felt stressed at work. The average man in the study held four jobs during his career, but some participants held up to a dozen or more jobs.

Do Any Studies Link Career Stress to Cancer?

Prolonged exposure to stress at work was linked to greater odds of cancer at 5 out of 11 cancer sites. Employment in at least one stressful job was linked to an increased chance of developing cancer of the lung, colon, bladder, rectum, stomach, and non-Hodgkin lymphoma.

Researchers acknowledged study limitations, such as over-reporting of stress among those who had cancer, but they maintained that if these links are substantiated, they could eventually churn up some important discoveries to advance science and medicine.

The group called for prospective studies to examine this question further—in other words, they point to the need for studies that begin with a group of healthy people, carefully measuring stress in a standardized way, and then years later do the analysis on cancer development, considering all the different sources of stress and changes over the span of the career, and controlling for other variables as much as possible.

It's a tall order.

Some takeaway points about stressful jobs:

  • The most stressful jobs included firefighter, industrial engineer, aerospace engineer, mechanic foreman, and vehicle and railway-equipment repair worker.
  • Perceived work-related stress sometimes varied depending on the specific job held.
  • Stress was attributed to “a high workload and time pressure, but also to customer service, sales commissions, responsibilities, financial issues, job insecurity, hazardous conditions, employee supervision, interpersonal conflict, and a difficult commute.”

How Might Stress Influence Cancer Risk: A Look at the Biology

How does stress affect the body?

Remember, psychological stress consists of physical, mental, or emotional pressure. If you imagine pre-historical human beings trying to survive on this planet, you get an idea of how stress tends to direct us in our daily lives. Our bodies release stress hormones such as epinephrine and norepinephrine that cause us to become alert to our surroundings and undergo more sophisticated threat assessments than we might do, say when laying down to take a nap or go to sleep. These hormones increase blood pressure, speed up heart rate, and raise our blood sugar levels so that we can summon our full strength, speed and wits to escape whatever the threat may be.

Researchers have published studies that link long-term, chronic stress to all sorts of different conditions, including digestive problems, fertility problems, urinary problems, and a weakened immune system. Such stress seems to lower our defenses—it’s no accident that people often come down with a cold leading up to an important event, especially when that event is causing them a lot of stress and anxiety.

According to the NCI, people who experience chronic stress are more prone to viral infections such as the flu or common cold and to have headaches, sleep trouble, depression, and anxiety. Also according to the NCI, however, the "case" for stress as an important cause of cancer is, at present, not very strong. There are some studies that show a link between various psychological factors and developing cancer, but other studies do not show this link.

How could stress theoretically heighten cancer risk?

One group of researchers is interested in how stress may influence people to engage in unhealthy behaviors such as smoking, overeating and drinking to excess, or binge drinking. In this model, it’s primarily the unhealthy behaviors that increase a person’s risk for cancer. A different camp is interested in the biochemical effects of chronic stress, itself, and the interactions with cancer development and progression. Each camp acknowledges that both mechanisms might be in play in the same person.

Stress and Its Interaction With Blood Cancers

Some studies have found that stress-related factors are associated with more rapid progression of several types of cancer, including blood cancers such as leukemia and lymphoma. When it comes to increased risk of developing cancers because of stress, results of studies have been pretty inconsistent, according to the authors of a paper published in the November-December 2011 issue of “Psychosomatic Medicine.”

These and other studies, however, have reported more consistent evidence to support the idea that things like distress, depression, and social isolation can have an effect on the rate that a cancer progresses, with these stressors being linked to more rapid cancer progression.

Analyzing Animal Studies

If you go to animal studies, there are findings that make a person want to ponder whether chronic stress might lead to the development and progression of certain cancers. One group of researches chose to study a kind of leukemia—pre-B ALL—using a mouse model. In humans, leukemia is categorized into four basic types by acute vs. chronic and lymphocytic vs. myelogenous. Of the four types, acute lymphoblastic leukemia (ALL) is the most common type of cancer in young children, and pre-B cell ALL is the most prevalent specific form of leukemia in children and adolescents.

Findings from studies done on mice have a nasty habit of not being applicable to humans, and so we are now in the realm of pure scientific theory. The pre-B ALL Mouse Study study was interesting, however, from the point of view of how the mind and body might theoretically be linked, and how this link might apply to blood cancer.

Researchers noted that there are nerves associated with the stress response that can signal the bone marrow, which is the site of all blood cell formation. While these nerve signals are believed to act on normal (non-cancerous) blood-forming cells (hematopoietic progenitor cells), this research group wondered whether stress might cause these nerves to signal bone marrow in a way that, over time, might also affect the progression of ALL leukemia.

The researchers made human pre-B ALL cancer cells that would glow, so that they could be monitored once transferred into the laboratory mice. They found that chronic stress could accelerate the progression of human pre-B ALL tumor via the nerve-signaling pathway. They speculated that the impact of such signaling on the ALL cancer biology was not direct, but through other, non-cancerous, cell types in the area, such as immune cells or other cells in the normal bone marrow.

Living With Cancer, Coping With Stress

The question of managing stress and coming to grips with a life threatening disease is a profound one, and one that cannot be dealt with adequately in the current format. However, if you have cancer, many people in your shoes have said that they benefited from cancer education, social support in a group, regular exercise, counseling or talk therapy, as well as medication for depression and anxiety.

According to the National Cancer Institute, coping is the use of thoughts and behaviors to adjust to life situations, and the institute notes that people cope in different ways. A person’s coping style is often linked to their personality.

It’s also important to realize that coping can be equivalent to a new part time job, of sorts. Give yourself some time to devote to it, and know that those job requirements can shift around during different stages as you reach new terrain in your cancer journey. There can be distinct emotions that come with the territory at each of the following stages, for instance: being diagnosed, being treated, reaching the end of treatment, being in remission, and learning the cancer has come back.

On the question of depression in cancer, the American Society of Clinical Oncology recommends that every patient with cancer be screened for depression when the diagnosis of cancer is first made, and on an ongoing basis, especially at key stages or times of change in the person's disease.

Sometimes it can be hard to identify depression in someone who has cancer. For instance, feeling like you are a burden to others is a common thought that can come up at one time or another when grappling with your condition. It doesn’t always mean you are depressed, but feeling excessively guilty about it might be a sign of depression. Feeling hopeless that you will be cured when you are near death is a normal state of mind, but having no hope at all, in other areas—no hope that you can be kept comfortable, or no hope that your offspring might continue to thrive in their lives after mourning your loss—these can be signs of depression.

A Word From Verywell

People use the term “cancer survivor” in different ways. Some cancer survivors know that the cancer will eventually take their lives, while others have been cured and can expect to live a full life. In either case, survivors are forever changed from the experience.

The future will no doubt continue to reveal new facets of the connection between the mind and the body in medicine and specifically in the area of cancer. For now, managing stress as best as you can can be helpful in living a higher quality of life.

Sources:

Blanc-Lapierrea A, Rousseau MC, Weiss D, et al. Lifetime report of perceived stress at work and cancer among men: A case-control study in Montreal, Canada. Prev Med. 2016 Dec 5;96:28-35. doi: 10.1016/j.ypmed.2016.12.004. [Epub ahead of print].

National Cancer Institute. Psychological Stress and Cancer. https://www.cancer.gov/about-cancer/coping/feelings/stress-fact-sheet.

Lamkin DM, Sloan EK, Patel AJ, et al. Chronic stress enhances progression of acute lymphoblastic leukemia via β-adrenergic signaling. Brain Behav Immun. 2012;26(4):635-641.

Continue Reading