OPINION. When you’re diagnosed, you go through a whole host of emotions. It’s not just the initial shock, the disbelief, the anxiety and morbid worry produced by the words “you have cancer”, it’s other stuff such as anger and denial. With the latter, the denial normally wears off as you finally accept the predicament.
In hindsight, the anger is interesting because there can be a mixture of thoughts including “why me“, “what could I have done to head this off“; and would you believe I was even angry that my diagnosis was going to affect my performance at work and even my personal credibility. We all react differently but in general terms our experiences can be categorised into 3 main areas: initial reaction, distress and then adjustment.
Initially, I was frustrated I didn’t know what had caused my cancer, perhaps my thinking was that I could warn others. Those feelings soon wore off as I discovered that no-one really knows why people succumb to certain cancers. If we really know what caused certain cancers and it was something in our control, that would lead to very clear prevention strategies such as we see with smoking and Lung Cancer for example.
If you don’t know what caused your NET, you’re not alone. According to several studies in the past 10 years, around 40% of cancers are preventable indicating that up to 60% might just be plain bad luck. Clearly this figure varies between cancer types with the biggest culprits being Lung and Skin cancer with too much exposure to tobacco and ultraviolet light respectively. However, the reports also pointed out that people can and will still get these cancers without significant exposure to the commonly preventable causes. The latest study is interesting because it raises the issue that some cancers may be totally unavoidable as they are caused by random errors associated with DNA replication. This study remains controversial because it undermines government prevention strategies. There’s a balanced article from Cancer Research UK which is a useful read (interesting quote … “Even if, as this study suggests, most individual cancer mutations are due to random chance, the researchers admit that the cancers they cause may still be preventable”).
Correlation does not mean causation
This is a really important point because I’ve seen so many posts in my community where people have assumed the opposite, e.g. “I have this disease or this experience and I also have a NET so there must be a connection”. Also I see patients get excited when they discover similarities between half a dozen NET patients without investigating incidence data or other statistics (including the fact that 6 patients out of the millions across the world does not equal a causation). So what do the terms correlation and causation mean? This is a highly technical subject so will try to keep it simple.
- Correlation is a statistical measure (expressed as a number) that describes the size and direction of a relationship between two or more variables. A correlation between variables, however, does not automatically mean that the change in one variable is the cause of the change in the values of the other variable. One practical, example would be an increase or decrease in the incidence data for (say) diabetes would not necessarily mean there should be a corresponding increase or decrease in the incidence rate for for Neuroendocrine Cancer.
- Causation indicates that one event is the result of the occurrence of the other event; i.e. there is a causal relationship between the two events. This is also referred to as cause and effect. To illustrate the importance, see this real world example:
In the same way that correlation does not mean causation, risks factors are just that, they are increased risks of succumbing to a disease and these risks may be realised to become the cause of the disease. But it must be emphasised that the presence of a risk factor does not mean there will be an effect. A good example in cancer is smoking. Smoking is the biggest preventable cause of cancer in many countries. There’s a chance of reducing the risk or even preventing the effect by stopping or reducing smoking. Not everyone who smokes will get cancer but it is a known risk factor.
Risk Factors for NETs. Not a lot is known about what actually causes most types of neuroendocrine tumours, so there aren’t many strategies to prevent them. People with certain risk factors are at a higher risk of developing neuroendocrine tumours than others, these risk factors include:
- A family history of multiple endocrine neoplasia (MEN) syndromes and other familial related syndromes.
- Hereditary paraganglioma/pheochromocytoma.
- Von Hippel-Lindau syndrome
- Neurofibromatosis Type 1
- Tuberous sclerosis complex.
- Certain conditions that affect the stomach’s ability to produce stomach acid, such as atrophic gastritis or pernicious anemia (e.g. Type 1 Gastric NETs), or Zollinger-Ellison syndrome (e.g. Type 2 Gastric NETs).
- Smoking tobacco (e.g. Small Cell Lung Cancer (SCLC)).
Risk factors are just risk factors and they do not mean these risks will always materialise into a NET. Many people claim environment and diet is a cause of NETs but there just isn’t currently any evidence to support that. However, one interesting find is a study funded by NET Research Foundation which is designed to discover the molecular causes of a Small Intestine NET (SiNET). In addition, they will investigate potential environmental causes, including epigenomic and infectious causes.
I also found one risk factor study in April 2020 which looked at “Early life exposures associated with risk of small intestinal neuroendocrine tumors”, James VanDerslice, Marissa C. Taddie, Karen Curtin, Caroline Miller, Zhe Yu, Rachael Hemmert, Lisa A. Cannon-Albright, Deborah W. Neklason. Published: April 23, 2020 https://doi.org/10.1371/journal.pone.0231991
This is a study based on the Utah Cancer Registry. Their conclusion is interesting and is as follows:
Using cases and birth cohort controls, we report geographic clustering of a birth locale associated with greater than 2-fold elevated risk of SINT, located central to historic coal mining communities. A retrospective analysis of industry and mining exposures further suggest birth/early life residence near construction industry, uranium mining and coal mining confers an elevated risk, specifically during the earliest time period when there were no regulations to reduce exposures to workers or the public.
These are elevated risk factors, not a scientifically confirmed cause of Si NETs
I often think about what actually caused my NET but I no longer worry about what the answer might be. I’m the first to admit I could have led a healthier life (like many others) but even that may not have had any impact or involvement in my cancer diagnosis. There doesn’t seem to be any point worrying because the clock cannot be turned back …..even if I knew, I would still have metastatic NETs, I still wouldn’t have the resected pieces of my anatomy. However, if the cause of my cancer was connected to a hereditary condition, clearly this would be important to know. That’s only my own opinion though.
Thanks for reading