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What is cancer?

What causes cancer? What causes this disease which seems to appear from nowhere? Where does it come from and why do so many people dread it?

Cancer occurs when the growth of cells in the body gets out of control and out of the normal process.

This uncontrolled growth results to what we call malignant tumors which eventually cause harm and damage to other healthy organs in the body.

Not all tumors, though are cancerous. The ones that are not harmful to the body are called benign tumors.

Normal cells mutate into cancer cells when the structure of the genes responsible for regulating the growth and development of cells have been drastically transformed.

Chemoprevention is a word that refers to the different methods used to prevent cancer using the natural or artificial means to inhibit the proliferation of cancer cells in the body.

What are the various causes of cancer?

Medical experts say that it is difficult to determine what exactly causes cancer but many different factors contribute to its growth and development. Following are some of them:

Various chemicals

Chemicals that cause cancer are called mutagens, from the word "mutate", because they cause a person's DNA to mutate or to undergo changes that cause damage to a person's genetic structure. Mutagens that cause cancer are called carcinogens.

Chemicals found in tobacco are considered the number one cause of cancer. Statistics show that the smoke coming from tobacco contains about 50 kinds of chemicals that cause cancer including polycyclic aromatic hydrocarbons and nitrosamines. Smoking is the cause of one in every 5 deaths that occur worldwide and one in every 3 deaths that occur in the developed and richer countries.

Previous studies have demonstrated that smoking has been associated with the high incidence of cancer of the lungs, esophagus, larynx, stomach, kidneys, bladder, head, neck and pancreas.

Cancer caused by chemicals in the workplace is also prevalent. The most known chemical to cause cancer in the workplace is asbestos which causes mesothelioma, the growth and development of cancer in the mesothelium, the delicate lining that protects our internal organs.

The lungs is the part of the body where mesothelioma commonly develops, particularly in the pleura, the lining that protects the exterior of the lungs and the walls of the chest.


Many people think that cancer is hereditary; that if our mother or father or another relative has cancer, we too can inherit the disease. Medical references, however, say that most types of cancers are not inherited meaning the disease did not come from any member of the family. If it is inherited then it could have been caused by a defect in the genes of a particular family member.

A very small percentage of the population - about 0.3 percent - are carriers of defective genes which accounts for 3 to 10 percent of all incidence of cancer worldwide. These inherited types of cancer include breast cancer, cancer of the ovary, Lynch syndrome or hereditary nonpolyposis colorectal cancer (HNPCC).


There are two sources of radiation that can cause cancer: the ionizing radiation and the non-ionizing radiation.

Ionizing radiation is emitted from either natural or man-made nuclear sources. An example of ionizing radiation is x-ray. Radiation cannot be detected by merely using our five senses and requires an instrument called a Geiger counter to determine its presence in the environment.

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Non-ionizing radiation is the type of radiation emitted from sources where there is not enough energy to ionize the atoms.


Certain types of hormones are primarily responsible for the growth and proliferation of cancer cells. Example are male and reproductive hormones that could be the cause of ovarian cancer, breast cancer, cancer of the endometrium, prostate cancer, cancer of the testis and also include bone cancer and thyroid cancer.


Infections in the body can cause cancer due to the presence of viruses, bacteria and parasites in the affected organs. Many diseases common to man are caused by some kind of viruses such as cervical cancer, liver cancer, cancer of the nasopharynx, Kaposi's sarcoma, and leukemia of the T cells.


Our well-being depends on the kind of food we eat to nourish our body. Diet, together with obesity and the lack of physical exertion accounts for 30 to 35 percent of deaths by cancer. Obesity has been associated with different types of cancer and accounts for 14 to 20 percent of total deaths.

Another factor that contributes to cancer risk is physical inactivity because of its adverse effect on a person's body weight, his endocrine and immune systems.

A diet that is deficient in fruits and vegetables and whole grains are linked to various types of cancers.

A diet high in salt is associated with cancer of the intestines.

A diet which would often contain aflatoxin B1 is associated with cancer of the liver.

A person who regularly chews betel nut can get cancer of the mouth.

Certain substances

There are certain substances that cause cancer through prolonged exposure to these substances. A classic example is asbestos which is the primary cause of mesothelioma, a rare type of cancer that affects the mesothelium, the delicate membranes that line a person's internal organs.

A survey conducted among cancer survivors about what they thought caused their cancer placed heredity as the number one cause; smoking came second followed by environmental and psychosocial factors.

Types of cancer


Carcinoma is cancer that grows from those cells that are found on the surface of the body called epithelial cells. It occurs when a cell's DNA is damaged and that cell starts to grow and spread without control.


Sarcomas are cancerous or malignant tumors that develop from connective tissues of the body. They are classified into two large groups: soft tissue sarcomas and bone sarcomas.


Adenocarcinomas are cancers that develop from the surface of a body organ and has secretory properties. Most prostate cancer cases are adenocarcinomas.


Lymphoma is cancer of the lymph nodes.

2 Types of lymphoma:

Hodgkin's lymphoma and non-Hodgkin's lymphoma


Leukemia is a type of cancer that develops from the bone marrow.


Chemotherapy is a medical procedure that is intended to destroy cancer cells. In this procedure, the chemical substance circulates throughout the body and destroy cancer cells that are in the process of developing in any part of the body.

Our body us made up of billions of cells. These billions of cells form body tissues. When these body tissues are fully developed, they stop dividing and multiplying into new cells. They only do so when tissues or organ of the body are damaged and have to be repaired.

In the normal process of cell division, two new identical cells are produced, then 4 cells, then 8 cells.

When the cells divide uncontrollably, this is when they develop into a mass of cancer cells called tumor.



Hormone therapy

Gene therapy



1. Cough or hoarseness of throat that does not go away

2. Chronic indigestion and problem in swallowing

3. An unexplainable presence of lump in the body

4. Abnormal vaginal bleeding and presence of blood in the urine and stool

5.A mole that changes its color and texture

6. Unusual occurrence of constipation and diarrhea

7. A body sore that does not go away

8. Difficulty in urinating

9. Unusual sweating at night

10. Sudden and unusual appearance of rashes

11. Unexplainable source of pain

12. Unexplainable loss of weight and appetite

13. Unexplainable cause of fatigue and tiredness

Here is a list of what are considered the most common types of cancer based on the number of occurrences of each cancer type in the United States.

Lung Cancer

Lung Cancer

Lung cancer

Lung Cancer is a type of cancer that affects the tissues of the lungs. This disease which is called primary lung cancer and given the medical term carcinoma originates from the epithelial cells, the tissues that line the surface of the lungs.

Among the types of cancer, lung cancer is the number one cause of death among men and women in the United States.

What to do: Stop smoking.

The 2 types of lung cancer are small-cell lung carcinoma and the non-small-cell lung carcinoma.

Common signs of lung cancer are coughing, sometimes with blood, difficulty breathing, and loss of weight but the the signs are determined by how the cancer cells are spreading, its effects on the body and the location of the cancer growth.

Cigarette smoking is considered the major cause of lung cancer. Cigarettes are known to contain 60 types of cancer-causing chemicals among them, nitrosamine, benzopyrene and radio isotopes. Nicotine, although not a cancer-causing substance significantly weakens the immune system making it less able to prevent the growth of malignant tumors.

In lung cancer, damage to the lungs is caused by substances found in exogenous genotoxic tobacco and cigarette smoke.

Regularly eating citrus fruits will greatly help in strengthening and keeping your lungs healthy. You can also supplement your diet with vitamin C for healthy lungs and for resistance to various diseases.

How to prevent lung cancer

The best way to prevent lung cancer is to avoid, at all costs, cancer-causing substances that can be transmitted by air such as smoke and polluted air and to always include in the diet vegetables and fresh fruits such as oranges, lemons, guavas, pomelos and others.

Evidence from previous studies show that smokers who have been taking huge amounts of beta carotene and vitamin A supplements have made their lung cancer worse.

So if you suspect that you have lung cancer, avoid foods containing beta-carotene and vitamin A. You should avoid most yellow colored fruits and vegetables because most likely, they contain beta carotene.

Prostate cancer

Prostate cancer

Pancreatic cancer

Pancreatic cancer

Prostate cancer

Prostate cancer affects the prostate glands. The cancer cells in the prostate glands can spread to your lymph nodes and bones.

Common signs of prostate cancer:

  • blood in the urine (hematuria)
  • painful urination (dysuria)
  • increased urination at night (nocturia)
  • difficulty urinating
  • pain
  • erectile dysfunction
  • difficulty having sex

What to do: You need to see a doctor but before you do, there are things that you need to write down so you can inform your doctor about them:

  • Take note of the changes,signs, and symptoms that you have noticed happening in your body
  • Write down all the medications you have taken since finding out that you have prostate problem.
  • Write down all the questions you would like to ask your doctor
  • If it is indeed prostate cancer, ask what stage it is.and how to treat it.

Pancreatic cancer

Pancreatic cancer originates from the tissues of the pancreas. It is the 4th leading cause of death in the US and 8th in the world.

The most common type of pancreatic cancer is Pancreatic Ductal Adenocarcinoma (PDAC) which is diagnosed unfortunately only after the disease has reached its advance stage. The patient usually dies within a year it is diagnosed.

The latest update on pancreatic cancer is that the presence of a large number of branched chain amino acids in a cancer patient's blood may help detect pancreatic cancer early. Reseachers revealed that an increase in the amount of BCAAs in the blood indicates the presence of tumor in the pancreas.

Pancreatic cancer does not show any symptoms in its early stage; however, by the time it is detected, cancer cells will have metastasized and already in its advanced stage.

Treatment of pancreatic cancer will depend on the stage of the cancer which could either be surgery, radiation, or chemotherapy.

Common signs of pancreatic cancer:

  • weight loss
  • pain in the upper part of the abdomen
  • loss of appetite
  • nausea and vomiting
  • heartburn, acidity
  • yellowing of the skin
Colorectal cancer

Colorectal cancer

Colorectal cancer

Colorectal cancer is more of a lifestyle rather than an inherited disease. It is a result of the impaired growth of cells in the large intestines particularly in the rectum and colon, and in the appendix area.

Common signs of colorectal cancer:

  • bleeding in the rectum
  • anemia
  • appetite and weight loss
  • streaks of blood in the stool, and
  • constipation that is getting worse.

Breast cancer

Breast cancer

Breast cancer

Breast cancer originates from the ducts or lobules, parts of the breast that are the main source of milk.

Common signs of breast cancer:

  • The most common sign that you have breast cancer is a lump in your breast that does not go away after your monthly period. Most women notice lumps in their breasts during their period which usually disappear as soon as the monthly period is over. However, if the lump does not go away after the period is gone, then that may be a sign that you have breast cancer.
  • breasts will gradually have different sizes
  • nipples will slowly become inverted
Endometrial cancer or Uterine cancer

Endometrial cancer or Uterine cancer

Endometrial cancer

Endometrial Cancer is the most common type of gynecologic cancer with approximately 35,000 women diagnosed of the disease each year in the US. This type of cancer, also called uterine cancer, occurs in the lining of the uterus called endometrium.

Common signs of endometrial cancer:

  • low blood pressure
  • pain in the lower abdomen
  • weight gain
  • presence of lymph nodes at the back of the head, in the neck, clavicles and chin
  • uncontrolled urination
  • for postmenopausal women: there is vaginal spotting, bleeding in between menstrual periods, and a clear, white discharge.
Bladder cancer

Bladder cancer


Non-hodgkin's lymphoma

Non-hodgkin's lymphoma or NHL includes all types of lymphoma or cancer of the blood particularly of the lymphocytes or white blood cells.

Common symptoms of NHL

  • swollen lymph nodes in the groin, armpits and neck areas
  • difficulty breathing accompanied with chest pain and coughing
  • chronic fatigue
  • bloating and pain in the abdomen
  • skin itching
  • low-grade fever
  • sweating especially at night
  • unexplained loss of weight


Leukemia is a type of cancer that affects the bone marrow or the blood which involves the proliferation of blasts or white blood cells.

Leukemia is a disease that is easy to treat using chemotherapy, bone marrow transplant, hormone treatment and medical radiation therapy. The success of the treatment will greatly depend on the patient's age and the type of leukemia the patient is suffering from.

Common signs of leukemia:

  • Excessive bleeding
  • Bruises
  • Weak immune system
  • Anemia
  • Fatigue
  • Swollen lymph nodes


Skin Cancer

Three types of skin cancer:

  1. Squamous cell carcinoma also called epidermoid carcinoma is a type of cancer that are produced by the body's squamous cells. These squamous cells are found mostly on the surface of the skin of hollow organs of the body. They can also be found lining the digestive and respiratory tracts.

Types of squamous cell carcinoma:

  • squamous cell skin cancer
  • esophageal squamous cell carcinoma
  • squamous cell cancer of the thyroid
  • squamous cell cancer of the lungs

2. Malignant melanoma is a type of malignant tumor of the cells that produce melanin, the brown pigment that can be found in the bottom layer of the skin, the uvea (middle layer of the eyes), the heart, the lining of the brain, and the bones.

Common signs of malignant melanoma:

  • Growth of lump in the skin that could later bleed, itch and ulcerate

An existing mole that changes in color, shape and texture.

3. Basal cell carcinoma

How to prevent skin cancer:

  • Use sunscreen. Using sunscreen or sunblock can prevent the growth of melanoma and squamous cell carcinoma.
  • Minimize indoor tanning and avoid sun exposure during midday.
  • Use sunscreen more often
  • Stop smoking




© 2013 Zee Mercado

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