Six cancer myths that can be challenged by science

Posted by ap507 at Jun 20, 2016 12:46 PM |
From mobile phones to deodorant sprays, PhD student Mohan Harihar discusses popular myths surrounding cancer

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Misinformation can be a dangerous thing.

There are all sorts of theories about how different habits can cause or prevent cancer.

However not all of these theories are true.  It was not until commencing my studies at university that I became aware of the scare-mongering that was associated with a lot of ideas about cancer – ideas which appeared to have been born from a number of unscientific sources.

Therefore it is important to address such myths as in many cases, they could influence people’s day-to-day decisions and lifestyle choices. 

This piece may help to dismiss some of these myths.

Myth #1: “There is a ‘cure’ for cancer…it just needs to be discovered!”

Yes and no.  

The idea of there being a definitive single cure for cancer is simply impractical and improbable. As discussed in a number of articles prior, the sheer complexity and number of ‘moving parts’ associated with cancer means a ‘one size fits all’ approach will never happen.

Nevertheless, the notion of there being multiple ‘cures’ for cancer, though seemingly distant at present, is more realistic. Currently a number of targeted treatments, such as Herceptin and Gleevec which have been in use since 1998 and 2001 respectively, have proven to be the closest thing to cures for certain breast cancers and ‘chronic myelogenous leukaemia (CML)’.  

However prolonged exposure to these drugs, or in some cases a unique mutation, has led to cancer cells becoming unresponsive to such therapies. In this way cancer cells adapt to become resistant to certain current therapies. Therefore measures need to be taken in the future when designing drugs to account for the ways cancer cells adapt.

This has been observed with CML patients treated with Gleevec. A certain mutation in some cases of CML has been shown to render Gleevec inactive due to a physical inability for the drug to interact with its target molecule. To circumvent this issue so-called ‘second generation’ drugs have been designed which are similar to Gleevec but with subtle structural alterations.  

By approaching drug design in this way we can move one step closer to definitive ‘cures’ for different types of cancers.

Myth #2: “You can ‘catch’ cancer."

Not in the traditional sense.

A contagious disease is defined as one which can be easily transferred from person to person.  The only occasions where cancers, in theory, could be ‘caught’ are 1) when they are caused by bacteria or viruses (such as cervical cancer caused by the human papillomavirus), or 2) following an organ or tissue transplantation.

With regards to cancers contracted as a result of microbial infection, whilst the microorganism can travel from one person to another, the cancer it can cause may not always occur. Factors such as quality of the host’s immune system or prior vaccination can prevent the disease from actually occurring despite the microorganism being present.  

In a similar vein the likelihood of getting cancer as a direct result of a transplantation procedure is minute – only approximately 2 out of every 10,000 transplants result in cancer. Medical professionals ensure all patients concerned are screened prior to surgery.

Myth #3: “I am more likely to get cancer if people in my family have (had) cancer- and if no family member has been diagnosed with cancer, I won’t get cancer myself.”

Not always – it depends on how the cancer developed.

A defective inherited gene can certainly pre-dispose an individual to a particular type of cancer and multiple family members will generally develop the cancer if this is the case. These cancers are described as being ‘familial’. Only approximately 5-10% of cancers (according to the National Cancer Institute) are inherited.

In contrast, the environment and the lifestyles we choose to lead dictate the likelihood of getting the remaining 90-95% of cancers (described as being ‘sporadic’). Cancer Research UK states 1 in 2 people born after 1960 in the UK will develop some form of cancer at some point in life – which are sporadic cancers.

Cancer is largely the result of numerous mutations to key genes. Whilst the transmission of some cancers through generations is evident, the fact remains that the number of ‘non-familial’ sporadic cancers in a given population is higher.

Therefore in the entire population, environmental factors such as smoking, excess exposure to the sun or poor diet are more likely to cause a variety of cancers than a single inherited defective gene that could lead to a specific cancer.

Myth #4: “Mobile phones can give me cancer”

It is unlikely – according to the most up to date evidence reviewed by the National Cancer Institute.

Electromagnetic energy waves fall into two categorizes – ‘ionizing’ and ‘non-ionizing’. Ionizing radiation has been shown to cause mutations which lead to cancer. On the other hand non-ionizing radiation has not been consistently shown to have this effect.

For years the concern has revolved around the radiofrequency energy (radio) waves emitted from mobile phones and its possible cancer-causing effects.

Radio waves are an example of non-ionizing radiation. Based on a number of studies to explore the different effects of mobile phone radio waves on the body, including those conducted on animals, the only consistent effect of radio waves to the tissues which absorb them is heating – which has not been shown to be mutation-promoting.

Some studies have suggested an association but this observation has not always been reflected or replicated in similar studies. Consequently the ambiguity has led to the International Agency for Research on Cancer, in 2011, categorising mobile phones as “possibly carcinogenic” to humans.

The European Commission Scientific Committee on Emerging and Newly Identified Health Risks concluded in 2015 that all the studies on mobile phone radio wave exposure did not provide enough evidence to state that mobile phones are causal factors of brain and other head and neck cancers.

Myth #5: “You can get breast cancer from using deodorant and antiperspirant sprays”

Due to conflicting evidence and the subsequent necessity for further studies in this area, there is nothing as yet to prove that breast cancer can be caused by deodorant and antiperspirant sprays.

Deodorants and antiperspirant sprays are routinely applied under the armpits in order to mask unpleasant odours and reduce sweating. This has prompted scientists (and non-scientists) to speculate as to whether they play a role in breast cancer development due to the region of the body which is exposed to the sprays.

The ingredients which have been primary culprits over the years include aluminium compounds and parabens (preservative chemical compounds). Studies have shown that both aluminium compounds and parabens can to some degree mimic the activity of the hormone ‘oestrogen’, which has been demonstrated to promote breast cancer cell growth.

One study in 2004 showed that parabens accumulated in 18 of 20 tissue samples taken from human breast tumours. However due to a number of experimental limitations (such as failing to analyse tissue samples from other areas of the body as well as not showing that parabens were only present in tumorous tissue) it was not clear whether or not parabens accumulated because of frequent use of deodorant or antiperspirant sprays and if the parabens themselves actually caused the cancer.

Moreover studies by other research groups have not been able to find associations between the use of such sprays and breast cancer.

Myth #6: “Cancer is solely a man-made phenomenon”

A common notion is that cancer is a modern, man-made disease brought about by the environment around us and lifestyles we choose to lead.

Yes, the environment and lifestyle as mentioned previously can play a significant role in increasing the risk of developing cancer. But the greatest cancer risk factor arguably is the one thing we cannot control – age.

When asked for a definition of cancer, people often omit the relevance and importance of ‘age’. One thing scientists take special care in including in their definitions nowadays is the age-dependent aspect of the disease.

Whilst mutations are what ultimately start tumour growth, the longer a person lives, the greater the likelihood unrepaired mutations to important genes will accumulate and the harmful effects of these will be experienced. Cancer Research UK reported that between 2011 and 2013 half of the UK cancer diagnoses were in people aged over 70 years.

It is of course possible that those who have lived longer and have led poor lifestyles throughout are more likely to experience the deleterious effects on their health. Nevertheless the risk of healthier individuals becoming more susceptible to developing cancer as they age also increases markedly.

On a daily basis we all experience various forms of DNA damage which, in theory, could go on to become tumour-promoting if left unrepaired. Those of us who live longer therefore sustain more of these mutations over a lifetime.  This coupled to a weakening immune system as we age makes for an ideal scenario for cancer cells to develop.

One dilemma which is therefore quite fascinating, and paradoxical, is that the ever-improving healthcare systems are keeping more people alive than ever before, but in the process of prolonging lives, are we also increasing the risk of people developing cancer down the road?

 

These are just a handful of cancer myths which often crop up. When it comes to science it is therefore imperative that there is always concrete scientific evidence backing or refuting certain claims in order to prevent scare-mongering and sensationalism.

 

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