Oxidative Stress: How Asthma, COPD, Oxygen May Increase Lung Cancer Risk

There is some evidence linking supplemental oxygen with certain cancers. So, is it true that supplemental oxygen may cause cancer? Why might this happen? Let's investigate the evidence.

In 2002, we wrote how high concentrations of oxygen were linked with cancer. That article noted that inhalation of an FiO2 of 100% for three hours increased the risk for developing cancer later in life. The reason was due to oxidative stress.

In a future post I want to investigate oxidative stress. What exactly does this do to the body? What causes it? What does it actually involve? How might it lead to cancer? So, that's a future investigation we will undertake.

For now, all you need to know is that oxygen, once it gets inside your body, splits into unpaired electrons. When a molecule has an unpaired electrons it is said to be unstable. It is referred to as a free radical. Free radicals will steal an electron from other molecules.

Under ideal circumstances, it steals an electron from an antioxidant. These are substances inside our body's meant to neutralize free radicals by donating an electron. Antioxidants can be ingested by eating certain foods, such as those containing vitamin C and E.

Sometimes, however, your body becomes overwhelmed with free radicals. There are certain disease processes that can cause this. Certain drugs can cause this, and one example is supplemental oxygen. In this case, your body becomes so overwhelmed with free radicals that they overwhelm antioxidants.

In excess, free radicals steal electrons from cells. So the cell now becomes unstable. It then it in turn steals an electron from a nearby cell. This creates a chain reaction of sorts. And this is what is referred to as oxidative stress. Cells become stressed. When this happens they release a substance called Reactive Oxygen Species (ROS). This triggers an immune response.

And, when this happens, they release chemicals such as cytokines and chemokines. These are your proinflammatory chemicals. They warn your immune system that something is wrong. And your immune cells release more cytokines and chemokines. These chemicals are helpful when you are exposed to bacteria and viruses. But, in excess, they can also be damaging to cells.

Other things that can cauuse oxidative stress like this are exposure to allergens and exposure to toxic chemicals in cigarette and wood smoke. This may explain how airways of asthmatics and COPD patients become chronically inflamed. So, it can explain many disease processes. And this includes cancers.

Oxidative stress may cause chronic inflammation. This may be what causes inflammatory diseases, such as asthma, COPD, diabetes, cardiovascular disease, and neurological diseases. And, as noted, it may also explain the links between some of these diseases and various cancers.

Under prolonged stress like this, oxidative stress is prolonged. So you end up with lots of ROS and similar substances roaming around. They can also cause gene mutations. Some of these mutations may cause the gene to produce harmful substances that may begin the cancer process.

This may explain the link between COPD and lung cancer. It actually might explain links between asthma and lung cancer. Studies show asthmatics are 2-6 times more likely to develop lung cancer than non-asthmatics. So, this may explain this link.

This is all very complex. There are very long and almost inexplicable articles on this stuff. But, my goal is to make it easy to understand. So, just keep in mind there is a lot more involved here than what I explain.

So, this may explain how long-term oxygen therapy, while relatively safe, is not without potential long-term side effects. It may also explain how those high doses of oxygen, even for short terms, may cause cancers later in life.
References.

1. Van Eaden, Stephan F., “Oxidative stress in chronic obstructive pulmonary disease: A lung and systemic process,” Canadian Respiratory Journal, Jan-Feb, 2013, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3628643/, accessed 5/28/17
2. Mandal, Anaya, “What is oxidative stress?”, News Medical Life Sciences, http://www.news-medical.net/health/What-is-Oxidative-Stress.aspx, accessed 5/28/17
3. CHSS Emory University, “What is oxidative stress,” Youtube.com. https://www.youtube.com/watch?v=9r07MhA_S9E, accessed 5/28/17
4. Kacmarek, Robert M., James K. Stoller, Albert J. Heuer, editors, “Egan’s Fundamentals of Respiratory Care,” 10th edition, 2013, Elsevier, pages 913
5. Domej, et al., “Oxidative stress and free radicals in COPD – implications and relevance for treatment,” International Journal of Chronic Obstructive Pulmonary Disease, 2014, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4207545/, accessed 5/29/17
6. "What happens in your body during oxidative stress?" HealthOlution. Youtube.com, https://www.youtube.com/watch?v=p1PEWZRHylo&t=15s, accessed 5/28/17
7. Parichha, Arpan, "Reactive oxygen species and oxidative stress," Youtube.com, https://www.youtube.com/watch?v=IhvyFBecgAY, accessed 5/2917
8. Nele, Cielen, Karen Maes, Ghislaine Gayen-Ramirez, "Musculoskeletal Disorders in Chronic Obstructive Pulmonary Disease," Biomed Research International, 2014, https://www.hindawi.com/journals/bmri/2014/965764/, 5/31/17
9. Eldridge, Lynne, "Does Asthma Increase The Risk Of Lung Cancer?" verywell health, 2017, June 19, https://www.verywellhealth.com/does-asthma-raise-the-risk-of-lung-cancer-2248983, accessed 8/19/19
10. Reuter, et al., "Oxidative stress, inflammation, cancer: How are they linked?" Free Radical Biology & Medicine, 2011, December 1, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2990475/, accessed 8/19/19

Is cancer caused by modern way of life?

Cancer is a disease that is expected to cause 171,000 deaths in 2010 alone, and 1, 529,560 new cases are expected to be discovered, with an overall cost of $263 billion. As RTs we take care of many patients with cancer, and as humans just about all of us know of at least one person with some form of cancer. Yet new evidence shows that we humans might be the cause of our own cancers.

According to Fiona Macrae, "Cancer 'is purely man-made' say scientists after finding almost no trace of disease in Egyptian mummies," at dailymail.co.uk, scientists have been thinking this way for many years. Yet a new study of Egyptian mummies showed only one case of cancer out of all those studies.

According to the article:

Michael Zimmerman, a visiting professor at Manchester University, said: 'In an ancient society lacking surgical intervention, evidence of cancer should remain in all cases.

'The virtual absence of malignancies in mummies must be interpreted as indicating their rarity in antiquity, indicating that cancer-causing factors are limited to societies affected by modern industrialisation.'

The study went by the belief that tumors would be better preserved than normal human tissue, and would be present in mummies if they were present at the time of death.

However, researchers were also aware that Egyptians might not have lived long enough to develop age-related diseases such as cancer. However, there was evidence of other age related diseases, such as hardening of arteries and brittle bones.

Yet Egyptian texts do mention cancer as a possibly caused by leprosy or varicose veins. So we know it was still occurring in ancient times, yet not as much as it is today.

Samples of Netherland bones also showed up only one case where cancer was evident.

I wrote a while back (click here)how lung cancer rates were very low until people started becoming addicted to cigarette smoke during WWI. I wrote here how as the number of people becoming addicted to cigarette smoke rose, so to did the lung cancer rate rise. And as those who smoke is on the decline, so is the lung cancer rate.

So there is clear evidence that most cancers are caused by humans, although not all.

Possible carcinogens may include the following:

1. Radiation
2. Cigarette smoke
3. Asbestos
4. Hepatitis B Virus
5. Hepatitis C Virus
6. Solar radiation
7. Formaldehyde
8. Pesticides: Used to control bugs and vermin
   
9. Paradichlorobenzene: Found in toilet bowl cleaners
10. Perchloroethylene: Found in dry cleaning fluid, spot removers, and carpet cleaners.
11. Smog: The air we breath, especially in cities
12. Deoderant
13. Soap
14. Hair spray
15. Laundry detergent
16. Hotdogs with nitrates in them (such as Oscar Myer)
    
17. Zodiac Flea Collars
18. Carpets with petrolatum based chemicals

For more carcinogens click here.

For more information about cancer, with statistics, click here.

I also should mention here that modern society and improved technology has also improved the quality of human life, and has increased the human lifespan from near 35-45 at the beginning of the 20th century, to about 80 years today.

Macrae concludes her article by writing:

Dr Rachel Thompson, of World Cancer Research Fund, said: Scientists now say a healthy diet, regular physical activity and maintaining a healthy weight can prevent about a third of the most common cancers so perhaps our ancestors’ lifestyle reduced their risk from cancer.'

Of course we can't live in a bubble, yet we can be aware of what we put in our bodies, and we should do a better job of eating well and exercising regularly. Or, as my grandpa used to say, "Anything in moderation."