What Is Cancer: Causes, Types, Symptoms, Treatment & Metastasis

It’s about the most widely Googled medical topic: What is Cancer? Let’s learn about cancer in the most simplified manner.

Cancer is a word which is widely misunderstood by the common people. Various myths have added worldly effects to its entity. Though medical science has evolved to the extent of knowing the molecular basis of its cause; but what causes cancer still remains an enigma!

Recommended reading: Detecting early signs of Breast Cancer by Breast Self Examination

What is Cancer?

Let’s read it loud and clear!

“It is the excessive growth of the normal tissue that leads to cancer.”

So, what is the difference between a cancer cell and a normal cell?

A normal cell is controlled by a supreme commander called DNA (Deoxyribo Nucleic Acid). This stays inside every human cell, exactly inside the chromosomes. This DNA is the authoritarian of every cell division.

Apart from normal cell division, one of the other important functions of DNA is that it is programmed to code for the normal proteins for the life to survive. It is very similar to a programmed software designed to behave in a particular format.

When this DNA gets denatured or de-stranded (weaken or broke), the normal coding genes also goes corrupt. They then code for the abnormal proteins which trigger the cells to behave violently, violating all the rules laid by the normal DNA. The cancer cell divides continuously and tirelessly forming a collected lump of abnormally growing cells called cancer. Functionally, the cancer cell forget about their actual destined task for which they actually exist!

Now the secrets and facts about cancer, let’s know them in detail-

1. Cancer cell can arise in any part of the body

This is the most acceptable fact! Practically, any organ, any tissue, and any cell type can give rise to Cancer. Be it the mouth cavity or the bones; every tissue inside the human body is capable of producing such abnormal growth under some adverse exposures giving rise to cancer.

2. Types of Cancer – Benign and Malignant

It has TWO types: Benign and Malignant are the two different types of cancer.

More often, the word ‘Tumor’ is used by the Doctors to denote the ‘Benign’ form of growth.

Let’s know, BENIGN v/s MALIGNANT!

The growth pattern of the cancer cell is what actually the reason what causes cancer!

Benign ones are silently growing and not involving the adjacent tissues. Consequently, this type does not spread to the farthest sites despite its large size. That’s Benign; sometimes labeled as ‘Tumor’ by the doctors.

On the other hand, Malignant is violent, quickly spreading to the nearby structures and to the farthest parts of the body. That’s Malignant nature! This is the true form of the cancer cell that leads to metastasis!

How do Cancers spread? What is Metastasis?

For every spread, there is a carrier! Here, in this case, it may any three of them: Blood, Lymph or Direct spread! This carrier spreads the cancer tissues to other sites of the body where it isn’t supposed to be. When such spread happens to other body organs, it’s a clean Check & Mate! This is what we call a Final staged Cancer, and practically there’s no turning back! This stage is termed as Metastasis in all Cancer types.


3. What causes Cancer?

The simplest known truth about cancer:

Cancer doesn’t spread person-to-person.”

Not even its wildest variety! There are only two major causes of Cancer: Genetic and Environmental.

Genetic Causes

Genetic causes are those which have direct influence over the genetic makeover of the human body. If the DNA strand already contains an ‘abnormal gene’ that codes for a preset abnormal protein synthesis, will cause the abnormal cells to multiply. These abnormal cells will not obey the command of remaining normal DNA; resulting in abnormal growth of the cells and tissues, thus causing cancer.


In simpler terms, DNA, the supreme commander of the gene flow and normal protein synthesis has now an abnormal unit of gene that codes for abnormal proteins in the cells.

Hence, when the abnormal proteins are synthesized in the cells, they do not recognize the supreme command of the ‘Normal DNA.’ These abnormal proteins reside in the cells and trigger these cells to behave abnormally and multiply uncontrollably.

In some other types of cancer, DNA of the body cells gets permanently damaged. And now it’s beyond repair that triggers the cells to respond to such abnormal activity. Ovarian and Breast cancer have an inheritance in first degree relatives commonly termed as Hereditary Breast and Ovarian Cancer Syndrome (HBOC).


Environmental causes

Environmental causes of cancer are the factors that have no genetic influence over the cancer cells. This cause of cancer is due to exposure of the body to certain harmful toxins, radiations, infections (viruses), or occupational exposure to certain chemicals. This leads to a major ‘change in the DNA segment’ of the cells, thus coding for abnormal proteins, developing cancer. This environmental exposure can be abrupt (mutation) or gradual (variation). It depends upon the intensity and frequency of exposure to the harmful agent.

The biggest myth about cancer is regarding eating superfoods and prevention of cancer. There is no scientific evidence claiming that superfoods like Garlic, Broccoli, Green Tea, Wheatgrass, Beetroot, etc prevent cancer.

4. Cancer Statistics & Facts about Cancer Spread

According to the American Cancer Society, declared in 2015, the most common cancer effecting in both the sexes is Lung cancer. While other major cancer sites are Breast Cancer in females whereas Prostate cancer in the males. In India, Cancer of the Oral cavity (India) remains high due to the habit of tobacco chewing.

According to WHO factsheets updated in February 2015; Among men, the 5 most common sites of cancer diagnosed in 2012 were lung, prostate, colorectum, stomach, and liver cancer. Among women the 5 most common sites diagnosed were breast, colorectum, lung, cervix, and stomach cancer.

Lung cancer statistics say that Hungary had the highest rate of lung cancer, followed by Serbia and Democratic Republic of Korea in 2012. And 85% times the cause is Smoking.

Breast cancer is the most common cancer in women worldwide and Belgium had the highest rate of breast cancer, followed by Denmark and France in 2012.

Prostate cancer has the highest incidence in Martinique, followed by Norway and France.

Women become susceptible to developing Cervical cancer following HPV infection (A virus called Human Papilloma Virus), but other environmental factors are required for the cancer to develop. Malawi had the highest rate of cervical cancer, followed by Mozambique and Comoros. About 84 percent of cervical cancer cases occurred in less developed countries.

Unknown facts: Food patterns & Cancer-

Consumption of red and processed meat has been associated with an increased risk of colorectal cancer.

Body fatness influences the levels of a number of hormones and growth factors, leading to the birth of many cancer in the body. Liver cirrhosis followed by Liver cancer is common due to Obesity causing NASH. Risk of Gall Bladder cancer is also increased in obese people.

Intake of high amounts of salts in form of pickled food and canned items cause stomach cancer as it causes Infection with the bacterium Helicobacter pylori.This bacteria thrives well in acidic environment and hence multiplying well in the stomach wall causing ulcers and cancer.

Alcohol increases the risk of cancer of the liver, oesophagus, mouth, throat (pharynx and larynx), breast, as well as bowel cancer in men. It also probably increases the risk of liver cancer and bowel cancer (in women).

5. Tumor suppressor genes- A Reality

Well, this is one masterpiece which no physician ever tells you!

Tumor Suppressor Gene!! What is it?

Practically every cell in the body is insured against the development of cancer. This is due to carriage of few typical gene families in the body named as Tumor Suppressor Genes or TSGs.

These TSGs stay in the DNA, and guard against every kind of cancer development. But, if these TSGs get deactivated or de-stranded; by an external stimulus or by defective gene expression, they lose the capabilities. They no longer protect against the development of cancer which they were previously programmed to do.

Thus, defective proteins are produced leading to irrational behavior of the cells, letting them multiply uncontrollably causing cancer.

6. Symptoms of Cancer – Nonspecific symptoms

Cancer patients can present from being totally asymptomatic to completely fragile. It depends upon the type of cancer, its extent and its severity at the time of diagnosis.

Some patients may present symptoms of cancer only with mild fever, loss of appetite and lethargicness.

While others may present with severely debilitating illness associated with body hormonal and electrolyte fluctuations commonly called as Paraneoplastic Syndromes.

7. Unknown Occupation-Related Cancers

Occupational exposure for prolonged periods can predispose a person to cancer. Most common is Lung mesothelioma which is prevalent in occupations exposing to Arsenic (Fungicides, Herbicides, Alloys and Semiconductor devices) and Asbestos (Floor Tiling, Friction materials and Roofing papers). Radon, Nickel, beryllium, and Chromium can also lead to similar patterns of lung cancers.

Asbestos is a leading agent causing occupational cancer in lung, skin, stomach and intestines. WHO has been working for the development of policy on the elimination of Asbestos-related-diseases.


8. Diagnosis & Treatment of Cancer

Top 5 questions which you need to ask your specialist when you are diagnosed with cancer

  • Type of cancer which you have?
  • Site of cancer?
  • Propensity to spread to other parts of the body?
  • Treatment options, duration of treatment and their side-effects?
  • Staging of your cancer and treatment of cancer?

Current trend for the Diagnosis and Treatment of Cancer is by Histology, Cytology, Imaging, Endoscopy, Molecular diagnosis, Flow cytometry, Tumor markers and Immunohistochemistry.

The treatment of cancer is widely known as either any of them or the combination of them: Surgery, Chemotherapy, and Radiotherapy. But very fewer people know that it is not true to every cancer.

Some cancers may be resistant to radiotherapy or chemotherapy; it’s because of what cell lineage they arise from. This also varies according to the staging of cancer.


Conclusion: What is Cancer? What causes Cancer?

Cancer is a curse! A devil! It’s true that one cannot control the genetic issues; it’s like born unlucky! But you can surely protect yourself from the environmental causes. The most important being Smoking!


It’s the most easily available poison in the market, and the cheapest too! It sends in hundreds of poisonous elements sure enough to cause cancer in almost any part of the body. And this is the most common carcinogen available today, that can explain, What is Cancer? And, what causes Cancer?

Dr Navneet Goyal

Dr Navneet Goyal is an Anesthesiologist Doctor, Internet Entreprenuer, Self-taught Marketer, SEO and a Growth Hacker! He has also learnt Web Designing, Lead Management, Digital Marketing & Financial Planning through various resources. His goal is to enhance the current Education model into a Motivational Driven Self Learning Platform.
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