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Lung Cancer, Non-smokers, and Risk Analysis for Life Underwriters: Expert Series Week 14

Oct 19, 2018 9:07:00 AM / by Elliott Dickson

Expert Series Lung Cancer

In this edition of our Underwriters Expert Series, we’re uncovering the risks associated with lung cancer – beyond cigarettes. Learn about other causes of this fatal disease and why life underwriters need to look at more than smoking status for assessment.

Cigarette smoking has long been the undisputed primary cause of lung cancer, with a whopping 80%-90% of all lung cancer cases being traced back to the habit. Lung cancer is also the deadliest cancer, with mortality rates upwards of 70% and overall resulting in more deaths than breast, colorectal, and prostate cancers combined. While it is unrealistic to expect cigarette smoking to lose its number one spot on the list of risk factors, it is also foolhardy to discount other root causes – however minor – especially given that some of them could be on the rise.

So, it might be surprising to hear that in Canada, 2015 saw 15% of all lung cancer patients with no history of smoking. This number could even be higher as of the present date. A similar US study tracked that the rate of non-smokers with lung cancer had increased from 8% to nearly 15%, from the early 1990's to some point between 2011 and 2013. Nonetheless, there is a certain stigma that surrounds the discussion of lung cancer: it’s your own fault that you picked up the cigarette, right? This is due in part to a lack of survivors to advocate for lung cancer issues (the mortality rates are high), and perhaps a lack of sympathy from the general population towards the diagnosis, given that it is often seen as a ‘preventable’ cancer. Smoking is still the single most preventable cause of cancer; however, people who have never smoked should not be so quick to dismiss the possibility of developing lung cancer.

Why Does this Topic Matter to Life Underwriters?

Lung shadows, pleural nodules, and hemoptysis – this installation of our Life Underwriter Expert Series highlights why life underwriters shouldn’t be so quick to write off potential lung cancer signs in non-smokers. You’ll learn to challenge conventional bias and about the other risk factors and demographics that may influence lung cancer development amongst those who have never picked up a cigarette.

4 Alternate Causes of Lung Cancer

Some of the causes of lung cancer in non-smokers may not be so mysterious. Secondhand smoking has long been a known cause, and though laws that ban smoking in public areas have helped to remedy this, they have not eliminated it as a risk. For non-smokers that reside with a smoker, there is a 24% increase in risk for developing lung cancer over their lifetime. In the US, secondhand smoke still accounts for as many as 7,000 deaths each year.

Asbestos is another familiar cause. While the manufacture of most asbestos-containing materials was stopped in 1979, stockpiles still exist, and asbestos products can be found in many Canadians buildings that were built up until the early 1990s. The so-called asbestos ban isn’t exactly sweeping either, as the mining and export of asbestos was supported up until 2011 when Canada’s last mines closed. If you’re wondering where the mined material was going to, the answer was often to poor countries in which regulations were lacking. Imports have still persisted though, and while it may no longer be used as a home insulator, it may find use in other means, such as brake pads and clutches for your car. The material itself is dangerous, as microscopic fibers can break loose to be inhaled, and can persist for a lifetime in the lungs. These fibers lead to scarring and fibrosis, which directly produces symptoms like coughing and shortness of breath and, over time, can lead to cancer. Asbestos workers, even those who do not smoke, are at a 5-fold greater risk of developing lung cancer than any other non-smoker.

There are other occupational hazards that have been shown to increase the risk of lung cancer, independent from smoking. These include glassware production, textile and ceramic workers, painters, chemists (looking at you, Walter White), metalworkers, and rubber production.

Familiar causes aside, according to the US Environmental Protection Agency (EPA), the leading cause of lung cancer in non-smokers is actually radon gas. Radon is a gas that forms when uranium decays. It occurs naturally outside in harmless amounts, but it can become dangerously concentrated in homes that are built on soil that is naturally rich in uranium. Like carbon monoxide, radon gas is colorless and odorless, so the only way to detect it is to test for it. Radon gas becomes lodged in the lining of the lungs, where it emits small amounts of radiation over time. This in turn leads to cell damage and, eventually, cancerous mutations.

How Can Life Underwriters Identify the Risk?

One thing that is a common trend amongst both smokers and non-smokers, is that the risk of lung cancer increases with age. Below age 40, the risk of lung cancer developing in non-smokers is said to be sufficiently rare. Due to this, there is a lack of studies available to begin to discuss causes and trends - that is not to say it doesn’t occur at all, just that the cohort has not been deemed a valuable study. The rate of incidence in people who have never smoked only reaches above 10 per 100,000 amongst people above the age of 60. While this is not remarkable, there is enough data to extrapolate that never-smoking men appear to have a greater incidence of lung cancer than never-smoking women; however, this difference doesn’t really become pronounced until above age 75.

Another interesting variation was seen in women, the rates of incidence is compared by geographical area: location-based analysis varies by as much as 30-fold. The overall lung cancer incidence rates were lowest in Africa and India, and highest in the Pacific Rim countries (e.g. Hong Kong, Philippines) and China. Although these rates do include the population of smokers – noted to be especially high in northeastern China and northern Thailand – it has also been hypothesized that there are other strong risk factors contributing to these rates. Namely, indoor air pollution either from unventilated coal fire pits/stoves, or the volatilization of cooking oils at high temperatures in open woks.

Recognizing Risk and Underwriting Lung Cancer

Overall, lung cancer death rates amongst never-smokers remain rare by conventional definitions; however, in the US at least, they are seen to be similar to the death rates from leukemia, endometrial cancer in women, and cancers of the esophagus, kidney, and liver in men. Also, these rates may be much more significant in other areas of the world. Nevertheless, better data is needed to fully explain the epidemiology of lung cancer in lifelong non-smokers. As this topic becomes more of an interest in both the clinical and insurance worlds, one can hope that more cohort studies will become available for analysis.

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Featured Underwriter: Elliott Dickson

Elliott graduated from the University of Toronto with studies in human physiology, sleep and respiration neurobiology, and philosophy. He ventured into underwriting shortly afterward and has continued his learning path by researching various niche topics relevant to insurance medicine. Elliott is currently a Senior Underwriter on the LOGiQ³ team, and has been an active contributor to underwriting content on the Blog, internal case clinics, as well as On The Risk.

Sources Used: 

Lung Cancer, Causes of Lung Cancer, Lung Cancer & Non-Smokers, Asbestos, Occupational Causes of Lung Cancer, Non-Smokers II, Non-Smokers III, Non-Smokers IV

Topics: Underwriting Expert Series, Life Underwriting

Elliott Dickson

Written by Elliott Dickson

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