What is Cancer
July 16, 2020 | Farah Jassawalla

What is Cancer

اردو میں پڑھیں

Cancer is a disease distinguished by the uncontrolled proliferation of abnormal cells that can divide, infiltrate, and destroy normal body tissue and organs and eventually spread throughout the body. The generalized growth control mechanism of our body gets disrupted. As cells become increasingly abnormal, old or damaged cells survive when they should die, and new cells form where they are not needed. These extra atypical cells divide uncontrollably and form a mass of tissue called a tumor.

Hallmarks of cancer

Cancer cells acquire these properties, typically by mutations in their relevant genes:

Self-sufficient growth signals

Insensitivity to growth-inhibitory signals

Evasion of cell death

Uncontrolled replicative potential

Development of sustained angiogenesis, a process through which new blood vessels form from pre-existing vasculature

Ability to invade and metastasize

How cancer arises

Cancer is a genetic disease; that is, it may be inherited from our parents or be caused by changes in our genetics that control the way our cells function. These changes can arise during a person's lifetime because of damage to DNA caused by certain environmental exposures, such as UV radiation, smoking, viruses, chemicals, and radioactive materials.

Normal body DNA contains tumor suppressor genes that prevent cancer. However, cancer cells with damaged DNA do not have this gene, which leads to abnormal cell growth.

How does cancer spread?

Cancer invades various parts of the body by a process called metastasis. The cancer cells break away from where they first formed and travel through the lymphatic system or blood vessels to different parts of the body. This metastatic tumor, which travels to any other body part, has the same name and cell type as the primary tumor.

Metastatic tumors can cause severe damage to bodily functions and have a high mortality rate.

Types of cancer

There are many types of cancers. Cancer is named for the organs or tissues where the tumors are formed — brain cancer starts in the cells of the brain, and breast cancer starts in the cells of the breast.

Cancer can be divided into five categories:

1. Carcinoma

2. Sarcoma

3. Lymphoma

4. Leukemia

5. Myeloma 


It begins in the epithelial tissue of the skin or in the tissue that lines internal organs, glands, or body structures, e.g., kidneys, liver, or stomach. Thus, a malignant neoplasm emerging in the renal tubular epithelium is a carcinoma, as are the cancers arising in the skin and lining epithelium of the gut.

Carcinomas account for 85-90% of all cancers.

Types of carcinomas include:


Refers to a carcinoma featuring a microscopic glandular pattern.

Squamous cell carcinoma.

Refers to carcinoma with features and characteristics showing squamous differentiation.

Basal cell carcinoma

This refers to carcinoma triggered by exposure to ultraviolet radiation and develops in the basal cell layer of the skin.

Adenosquamous carcinoma

Refers to a special type of heterogeneous tumor containing both adenocarcinoma and squamous cell carcinoma.

Anaplastic carcinoma

This refers to a group of high-grade carcinomas that feature cells lacking distinct histology and cytology. These are also called as poorly differentiated or undifferentiated carcinoma.


Malignant tumors developing from connective tissues, such as cartilage, bones, muscles, are called sarcomas. Cancers of fibrous tissue origin are classified as fibrosarcoma, and a malignant neoplasm composed of bone cells is classified as osteosarcoma.


Lymphoma is the cancer of the lymphatic system, which produces white blood cells and cleans body fluids. The lymphatic system consists of the spleen, lymph nodes, thymus gland, and bone marrow.

It can be divided into two main categories:

Hodgkin's lymphoma

Non-Hodgkin's lymphoma


Leukemia, or blood cancer, is a cancer of bone marrow. Bone marrow produces blood cells, e.g., white blood cells, red blood cells, and platelets. The four main categories of leukemia are:






Myeloma is a cancer of the plasma cells of the bone marrow. Plasma cells help us fight infections by making antibodies against them. 

Risk factors

Old age



Exposure to certain carcinogens, e.g., benzidine, betel nuts, etc.

Unprotected sun exposure 

Radiation exposure

Viruses (human papillomavirus) and bacterias 



Lack of physical activity




Avoid alcohol and smoking

Stay protected from the sun

Apply sunscreen

Cover exposed areas of your skin

Stay in the shade 

Stay indoors when the sun's rays are the strongest, from 10 a.m. to 4 p.m.

Eat a healthy, balanced diet

Eat plenty of fruits and vegetables

Limit processed meats

Maintain a healthy weight and exercise daily for at least 15 minutes 

Get vaccinated against the viruses 

See your physician regularly so they can screen you. This increases your chances of diagnosing any possible cancers and treating them right away. Companies like https://www.shifa4u.com/ provide these screening tests. Lab tests, imaging, and radiology are done at discounted prices. 



Surgery is the procedure in which a surgeon removes a tumor from the body.

Radiation therapy

It is another treatment option that uses high doses of radiation to kill cancer cells and shrink tumors.


In chemotherapy, medication is used to kill cancer cells.

Stem cell transplant

It is a procedure in which a patient receives healthy stem cells to replace damaged stem cells.


It is a kind of biological therapy that helps boost the body's natural defenses to fight cancer.

Targeted drug therapy

It is a type of treatment in which drugs are designed to target specific cancer genes without affecting normal cells.

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Farah Jassawalla

Farah Jassawalla is a graduate of the Lahore School of Economics. She is also a writer, and healthcare enthusiast, having closely observed case studies while working with Lahore's thriving general physicians at their clinics.