Cancer 101 - A Factual Overview

Many years ago, cancer was taboo, with far too few conversations taking place about the     ‘Big-C’. But thankfully, this disease has now been brought into the open and there is hardly a day goes by without hearing about some aspect of cancer on TV. This disease is now openly discussed, but this is unsurprising considering that half of us will be diagnosed with cancer at some stage of our lives. It is a very common chronic disease, and it continues to grow with the ageing population, making it now the biggest cause of death having surpassed cardiovascular disease.

The Stats

In the US for example, 1.8 million people were diagnosed with some form of cancer in 2020 with 17,000 of them being young children. USA health care spending on cancer and related care was huge, topping over $150 Billion in 2018¹.

In the UK, lifetime risk is 50%, meaning that 1 in 2 of us will be diagnosed with cancer at one stage in our lifetime, with risk increasing as we age of course. Fifteen percent of these cases are still caused by smoking, even now, when the vast majority of people are well aware that smoking is a huge risk factor for lung cancer. ²

According to Cancer Research UK, they estimate that 38% of all cancer cases are preventable. More about that later when we discuss causes.

One surprising fact is that there are over 200 different forms of cancer, with each type being a different disease with different treatment regimes. This is really due to the fact that we have over 200 different cell types in our body, with each being prone to cancer. It is this heterogeneity that continues to make cancer so difficult to combat.²

Generally cancer rates are highest in countries whose populations have the highest life expectancy, the highest education and the highest standard of living, which is quite counter intuitive. The most common cancers in men are lung, prostate, colon, stomach and liver, whilst in women, the top five include breast, colon, lung, cervical and stomach.²

What is Cancer

With normal healthy cells, they tend to self-replicate on a continual basis to form new and healthy cells. This process is tightly controlled, ensuring that replication is precisely managed. Not too fast and not too slow. At the end of their useful life, these cells tend to die in a programmed fashion, making way for these newly formed healthy cells. This normal cell death is called apoptosis and is a perfectly normal way of getting rid of cells which are no longer useful or healthy. It is this balance between cell growth and cell death that produces ‘homeostasis’ which is basically a healthy cellular equilibrium.

cancer however is an overall uncontrolled and aggressive growth of cells. These cells will behave in a totally different manner to normal cells and can grow uncontrollably causing cellular hypertrophy, where the cells simply grow and grow causing an expanding mass which, depending on where the mass is formed, can cause serious health problems.

Sometimes the cancer cells can change or mutate so much, that cells which are unrelated to the original cancer cell  can start to appear. This is why some cancers can even contain a mixture of strange cells more akin to tooth, bone, muscle and so on.

How Genetics are Involved in the Causes of Cancer

Cancer is a function of age, diet and also our environment, but can also be influenced by our own genome.

It is actually a genetic disease caused by errors and damage to our DNA which in turn causes DNA mutations. If unrepaired, then this ongoing damage to the DNA will lead to an accumulation of mutations and errors leading to ‘genomic instability’ which is when the DNA itself fails to produce the correct proteins needed for a whole host of metabolic functions.

DNA contains what are called ‘bases’ (labelled as either A, T, C or G). It is how these bases twin up with each other that gives DNA and the whole genome its overall ‘genetic instruction’ on what proteins it needs to make, to maintain our overall health. If these so called ‘base pairs’ (eg A paired with T) are not 100% correct, then this DNA becomes mutated and will behave in a fashion that can  cause health issues.

A common example of DNA damage is that caused by ultraviolet light, from sunlight, which arises from the very high energy part of the sun’s spectrum. This UV light is so energetic that it can break chemical bonds within the DNA double helix, as shown in the diagram below, leading to DNA which then fails to function perfectly.

In this illustration, the energetic UV light is enough to cause a breakage across the helix caused by the break to the two base pairs. This DNA, unless repaired, will now potentially cause a health problem.

Other ways of causing DNA interference includes chemicals that again, are highly reactive such as benzopyrene in smoke . These carcinogenic chemicals or toxins are called genotoxins and these can interfere with the DNA molecule itself causing replication errors, thereby leading to potential cancers.

However, though there are many thousands of DNA errors every minute within our body’s  biochemistry, the vast majority of these are corrected by what are called ‘tumour suppressor genes’. These special genes keep us safe, at least most of the time. Unfortunately, there are other genetic processes that can arise  which inhibit the effectiveness of these repair genes. These include the activation of ‘oncogenes’. Normally these ‘unhealthy’ oncogenes are switched off meaning that they are silent and undamaging. But on occasion, they switch on ,causing DNA problems. Another issue that can arise is when the DNA repair genes are defective or switched off, thereby lowering our defences against DNA damage.

General Contributors to Cancer Risk

There is no such thing as ‘zero risk’. Life is full of thousands of risks , though regarding cancer risk, there are many things we can do to lessen this risk. But ageing is unfortunately not one of those……in fact it is the largest risk factor and there is little we can do about it.

Ageing is the biggest risk factor to cancer with cancer risk rapidly growing after the age of around 50-60 years. For example, there are less than 25 cases per 100,000 under 20 years, whereas this rapidly increases to more than 1000 cases per 10,000 after the age of 60 years.³

(Source: National Cancer Institute, USA)

Excess intake of alcohol is another large risk factor that can significantly increase risk of cancer of the mouth, throat, oesophagus, larynx, liver and even the breast. After all, alcohol has been proven to be a human carcinogen, so it is unsurprising. In fact, both ethanol (alcohol) itself and its sister by-product, acetaldehyde are both carcinogenic to humans. On the other hand, there is a certain substance called resveratrol found in red wine which has been shown in some studies to inhibit cancer, though the data is too varied to make any firm conclusion.

Our diet too will have a significant effect on our overall health and also that of cancer risk too. There are many studies showing the carcinogenic potential of barbecued food, smoked food, the addition of nitrites and the many food nutrients that can cause inflammation. Long term or chronic inflammation is a large contributor to the onset of cancer due to DNA damage, caused by stressful reactive free radicals otherwise known as oxidative stress.

In addition, an intake of too many calories (hypercaloric diet) can lead to obesity, which itself has been strongly linked to both diabetes and also cancer itself. Sugar, though not officially classified as carcinogenic, has been shown to play a role in the ongoing ‘feeding’ of cancer which requires a high amount of sugar to aid its aggressive proliferation.

Sunlight itself is well known to have carcinogenic properties, especially when excess sun exposure occurs day after day. The sun itself, tanning lights and sunlamps all emit high energy ultra-violet radiation which is capable of causing not only damage to the skin, but also the cell DNA itself, thereby raising the potential for skin cancer.

As with most things in life, it’s all about balance, so getting that ‘dose’ of sunlight for the production of vitamin D is key to health, whilst avoiding excessive exposures which can lead to various types of skin cancers. A high quality cream with an SPF of at least 15 will be a healthy daily regimen to lessen the risk of both damage and also skin cancer itself.

Genetics plays a role in cancer too, as cancer is after all a type of genetic disease. Cancer itself of course cannot be directly passed down from parents to children. However, there are certain genes that can be passed down and if these are ‘high risk’ genes, then it is quite possible that these genetic entities may increase (or decrease) the risk of cancer. Scientists believe that only around 10% of cancers are directly inherited leaving us all to ‘do our best’ from a point of view of diet, exercise, sleep and stress management, all of which play key roles in the onset of various cancers.

Other Toxins such as various petrochemicals can be highly carcinogenic. These include such chemicals like benzene, formaldehyde, coal tar, ethylene oxide, vinyl chloride, certain pesticides and many more, all of which are used ubiquitously in our daily lives across thousands of products. Minerals too such as arsenic, beryllium, cadmium, mercury and even radon, the radioactive gas within rocks, are all carcinogenic and again, exist throughout our lives.⁴

How are Cancer Cells Different

Cancer cells tend to grow in the absence of signals telling them to grow and stop. They seem to just replicate uncontrollably and ignore the normal process of cell signalling.

Cancer cells can have variations in shape, unlike normal healthy cells. They can have larger and misshapen nuclei and also carry an abnormal number of chromosomes.

Apoptosis or programmed cell death, also evades these cancer cells making them dangerously out of control. Even more ingenious, these cancer cells have the ability to form new attached blood capillaries known as angiogenesis, enabling the cancer cells to receive all the oxygen, sugar and other nutrients they need from our own nutrition.

Cancer has another trick up its sleeve to evade attack by the immune system too. Somehow, the cancer cells can ‘hide’ or become transparent to the body’s own immune cell defence. This is especially serious, as normally our immune system is incredibly effective at killing cancer cells and dealing with DNA mutations before they have any chance of becoming problematic. Furthermore, some cancer cells even develop the ability to convince the immune system to protect the tumour itself. This is why cancer is such a difficult disease to treat and cure. It is so complex and cancer cells seem to have the ability to outwit the body’s normal biochemistry.

Types of Cancer

Though there are over 200 types of cancer, but in essence, these fall into four basic types. ⁴

Benign Cancers

Cancers can be totally benign meaning that growth is limited to a single area and is totally localised. Benign cancers are usually less dangerous and are treatable with a very high degree of success. However, some benign cancers can grow in places where they can cause mechanical damage such as the brain, and therefore have to be excised carefully. Even though the cells are unlikely to spread further, the mass itself can cause pressure, thereby interfering with the brain’s overall function.

But cancer cells can of course travel to other parts of the body and metastasize into other parts of the body. However, the cancer is still very much the type of cancer that originated at the primary site. For example, if prostate cancer spreads to a bone site, then that cancer is still referred to as prostate cancer and the treatment will be for prostate cancer. It is these metastases that unfortunately are responsible for around 90% of cancer deaths, demonstrating again that early detection is the key to successful cancer survival.

Pre-Cancer

Cancer does not suddenly start from nothing. It usually occurs when cells start to grow uncontrollably and form more and more mass. Initially this mass is very small and not necessarily cancerous to start with.

In simple terms , there are three stages of pre-cancerous cell development.

1/ Hyperplasia:

This is simply an expansion of additional cells causing a very small lump, where the cells themselves are identical to the cells around them. This is called ‘hyperplasia’ and occurs when these cells multiply faster than normal with extra cells building up adjacent to each other. ⁵

2/ Dysplasia:

This is a more advanced condition than hyperplasia. In dysplasia, though there is also a build-up of extra cells., these cells look abnormal and there are changes in how the tissue is organized. In general, the more abnormal the cells and tissue look, the greater the chance that cancer will form later. Some types of dysplasia may need to be monitored or treated, but others do not. An example of dysplasia is an abnormal mole (called a dysplastic nevus) that forms on the skin. A dysplastic nevus can turn into melanoma, although most do not.

3/ Carcinoma in situ:

This is an even more advanced condition than dysplasia, although it is sometimes called stage 0 cancer by some doctors. Technically though, it is not cancer, because the abnormal cells do not invade nearby tissue the way that cancer cells do. But because some carcinomas in situ may become cancer, they are usually treated as such.

A good example of how these various pre-cancerous phases progress is shown below in the colon example, where hyperplastic lumps can morph into early adenomas and then into fully blown cancer. Polyps are quite common in older adults and are easily removed during a standard colonoscopy.

This is why early diagnosis is key to cancer treatment. An early removal of a pre-cancerous lump can make the whole treatment regime so much more successful with a much better outcome for the patient. Again, it’s worth highlighting that around 90% of cancer deaths are due to these metastases, making early detection so important to survival rates.

Survival Rates

One of the most common questions people have is about survival rates, with some cancers being quite deadly, whilst others have extremely high survival and cure rates.

The table below from Cancer Research UK shows the 10 year survival rates for a whole range of cancers.⁶

Clearly lung, brain and pancreatic cancers seem to be the very worst with low rates of survival, while cancers of the testis and  prostate, melanomas and lymphomas have a much higher survival rate generally speaking. Undoubtedly , there will be scientific reasons for this, but this article is too brief to go into the details as to why there are such large differences of pathogenicity.

Can Cancer Ever be Cured?

Today, cancers that respond to treatment are not considered outright cured because there is always a potential they could return some time later. Instead, they are referred to as being in complete remission or evaluated as having no evidence of disease (NED), meaning there is no detectable cancer in the body.

A partial remission is exactly as it states ie that the cancer is still detectable but has decreased in size or decreased in the number of cancerous cells, such as in leukaemia.

Having said all this, there may still be some cancer cells present even when the current techniques of detection fail to observe any cancerous cells at all. The word ‘cure’ is in reality too precise and certain a word to use in the world of cancer, though some cancers such as breast, prostate, thyroid, testicular, melanoma and also Hodgkin lymphoma can be essentially considered cured if the cancer is detected and treated early.

The major problem with cancer is that it is not one single disease but over two hundred types, all with their own challenges and variable biochemistries. Even when two cancers are the same tissue type, subtype and even stage, they can still behave in different ways with different outcomes.

Overall, around 90% of cancer deaths are due to metastases and not necessarily due to the original tumour site. This is why early treatment is so important to a successful outcome.

The ‘big three’ and main cancer therapies ie surgery, chemotherapy and radiotherapy, have been the main focus since the 1950s in reality.

 However, these techniques are now being used more and more with additional or ‘adjuvant’ technologies such as targeted therapy, immunotherapy and hormone therapy.

1. Targeted therapy: This type of therapy involves drugs that target specific molecules or pathways involved in cancer growth and progression. Targeted therapies are often used in combination with chemotherapy and other treatments to provide more effective cancer treatment with fewer side effects.
2. Immunotherapy: This type of therapy involves drugs (such as ‘checkpoint inhibitors’) that help the immune system recognize and attack cancer cells. Immunotherapy can be very effective for certain types of cancer, and it is often used in combination with other treatments.
3. CAR T-cell therapy: This is a type of immunotherapy that involves taking a patient's own immune cells, modifying them to better recognize and attack cancer cells, and then infusing them back into the patient's body.
4. Precision medicine: This approach involves using genetic testing and other advanced technologies to identify specific mutations and other abnormalities in a patient's cancer cells. This information can then be used to tailor treatment to the individual patient's cancer.
5. Radioembolization: This is a type of targeted radiotherapy that involves injecting tiny radioactive particles into the bloodstream to deliver radiation directly to the tumour.
6. Cancer Vaccines: The same mRNA technology that was used to create COVID-19 vaccines is also being tested for cancer treatment. An mRNA cancer vaccine could target specific proteins found in cancer cells and be individualized for a person's specific type of cancer. In theory, these vaccines will be able to help the immune system learn to recognize the cancer cells as invaders, so they can be eliminated. More than 20 mRNA-based vaccines entered clinical trials by 2021, with some promising outcomes in treating solid tumours.

These advanced therapies are just a few examples of the many innovative approaches being used in cancer treatment today. As our understanding of cancer biology and treatment continues to advance, we can expect to see even more effective and personalized treatments in the future.

Early Detection is the Key to Success

1. Regular Cancer Screenings: It is recommended that people undergo regular cancer screenings as per their age, gender, and risk factors. Common cancer screening tests include mammograms for breast cancer, Pap tests for cervical cancer, colonoscopies for colorectal cancer, and PSA tests for prostate cancer. There are others of course but these are the most common techniques on offer.
2. Know your Body: You should be aware of the changes happening in your body, including any lumps, bumps, changes in skin colour or moles, persistent cough or hoarseness, changes in bowel habits or bleeding and any other unusual symptoms. If you notice anything unusual, see your doctor immediately.
3. Family History: People with a family history of cancer are at higher risk of developing cancer themselves. It's important to share your family's medical history with your doctor, who can determine if you need to undergo additional screening tests. Again the earlier this is done, the better.
4. Genetic Testing: Certain genetic mutations can increase the risk of developing cancer. Genetic testing can identify if you carry these particular genetic mutations, and your doctor can recommend appropriate screening and prevention measures.

It’s so important to be proactive about your health and seek medical attention if you notice any unusual symptoms or changes in your body.

In addition, in recent years, there have been significant advances in cancer detection techniques, including the development of blood biomarkers. Here are some of the modern techniques for detecting cancer:

1. Liquid Biopsy: This is a non-invasive technique that involves analysing blood, urine, or other body fluids for cancer biomarkers, such as circulating tumour cells and cell-free DNA (cfDNA). Liquid biopsies can detect cancer at a very early stage and can also be used to monitor cancer progression and treatment response. However at this time these tests are still unfortunately not 100% precise and more research is needed to improve their accuracy.
2. Molecular Imaging: Molecular imaging uses various imaging techniques, such as PET and MRI, to detect cancer at the molecular level. It involves injecting a small amount of radioactive material into the body, which accumulates in cancer cells and can be detected by the imaging equipment.
3. Artificial Intelligence (AI): AI algorithms are being used to analyse medical images, such as mammograms and CT scans, to detect cancer at an early stage. These algorithms can detect subtle changes in the images that may not be visible to the human eye. This is an exciting area of research which is already making an impact in cancer detection.
4. Cancer Antigen (CA) Tests: These are blood tests that detect specific proteins, known as cancer antigens, that are produced by cancer cells. Elevated levels of these proteins in the blood can indicate the presence of cancer.
5. Proteomics: Proteomics is the study of proteins and their functions. It involves analysing the proteins in a blood or tissue sample to identify biomarkers that are specific to certain types of cancer. Proteomics can be used for early detection, diagnosis, and monitoring of cancer.

These modern techniques for detecting cancer are still in the early stages of development, and more research is needed to validate their accuracy and effectiveness. However, they offer promising new approaches to detecting cancer at an early stage, which can improve outcomes for cancer patients.

How to lower Your Risk

Cancer will unfortunately affect around 50% of us at some time and there is no simple way of necessarily avoiding cancer with 100% certainty. However, you can reduce the risk of cancer by following a few fairly simple recommendations:

Don't smoke: Smoking is one of the leading causes of cancer. Quitting smoking, or not starting at all, is one of the best things you can do for your health. Also lung cancer itself can be a particularly nasty and difficult to treat cancer, so it’s best to just stay well away from smoking.

Maintain a healthy weight: Being overweight or obese can increase your risk of several types of cancer. Maintaining a healthy weight through a balanced diet and regular exercise is fundamental to risk reduction. This is easier said than done and life of course is a balance. However, obesity is a large risk factor so again, let’s at least follow these two recommendations at least in part.

Eat a healthy diet: Eating a diet that is rich in fruits, vegetables, whole grains, and lean protein can help reduce your risk of cancer. Limit processed and red meats, especially barbecued meats, as charcoaling and smoking of the meat is known to be carcinogenic. And avoid excessive alcohol consumption, as again, we know that alcohol itself is also carcinogenic. Avoiding a high sugar and high fructose intake will also reduce cancer incidence, as it is well known that cancer requires high amounts of glucose to replicate and grow.

Protect your skin: Exposure to ultraviolet (UV) radiation from the sun or tanning beds can increase your risk of skin cancer. Protect your skin by wearing protective clothing, using a high factor sunscreen, and avoiding tanning beds.

Stay physically active: Regular physical activity can help reduce your risk of cancer. This has been proven time and time again in many scientific studies. Aim for at least 30 minutes of moderate physical activity, such as brisk walking, most days of the week. If you can manage more than this, then that will be an added bonus.

Get recommended cancer screenings: We have spoken about the importance of early detection of cancer as this can greatly improve your chances of a successful treatment. Talk to your doctor about which cancer screenings are recommended for you based on your age, gender, and other risk factors.

Avoid exposure to harmful chemicals: Limit your exposure to harmful chemicals, such as asbestos, benzene, petrol, smoke, pesticides, heavy metals particulates, dust, and organic solvents in general which are known to increase the risk of cancer.

Consider using Nutritional Supplements:

Getting a daily intake of all the required vitamins and minerals is key to our overall health. Public Health England data shows clearly that the vast majority of us are failing to reach the RDA (recommended intake) on many of these key micronutrients, so why not consider a multi-nutrient supplement. Also avoid single mega-does of single vitamins/minerals and these can be potentially harmful at these huge doses.

Vitamin D in particular is receiving a lot of attention now in terms of its anti-cancer properties and it is known that the majority of us are quite deficient in vitamin D, especially in the winter months. Ensure that any supplement you take is made to GMP (Good Manufacturing Practice) which is the highest quality standard available in the UK.

References

1. IARC USA
2. Cancer Research UK
3. Anti Cancer Research, 36: 5009-5018 (2016)
4. Introduction and Basic Concepts of Cancer (Book), Devivasha Bordoloi et al.
5. London School of Hygiene EPM307, GN09
6. England and Wales, 2014, Cancer Research UK data