WHAT IS CANCER

Cancer is a condition in which some cells in the body grow out of control and spread to other parts of the body. Cancer is defined as an abnormal proliferation of bodily cells. Each one of us is born with the potential to develop cancer. When a cell or group of cells programming is disrupted, growth can spiral out of control. Cancer develops when aberrant cells proliferate uncontrollably and spread beyond their natural boundaries, occupying adjacent body parts or spreading to other organs. The latter process is known as metastasizing and it is a leading cause of cancer-related death. Cancer is also known as a neoplasm or a malignant tumor. 

Cancer cells differ from Healthy/ Normal cells in the following ways :
1.    Cancer cells proliferate in the absence of signals to do so. Normal cells can only develop in response to such signals.
2.    Cancerous cells spread to different sections of the body after invading surrounding sites. When normal cells come into contact with other cells, they cease growing and the majority of normal cells do not travel around the body. 
3.    The immune system generally removes damaged or normal cells, thus the cancer cells hide from it.
4.    Cancerous cells instruct blood arteries to expand in the direction of tumors. The blood veins provide oxygen and nourishment to tumors while also removing waste items from them. 
5.    Multiple chromosomes alterations, such as duplications and deletions of chromosome sections, accumulate in cancerous cells. The number of chromosomes in some cancer cells is double what it should be.
6.    Most cancer cells deceive the immune system into protecting the tumor rather than attacking it.
7.    Signals that typically instruct cells to stop dividing or die are ignored by cancer cells( a process known as programmed cell death or apoptosis).

Cancer cells cannot survive without their abnormal behavior, therefore, making it easy for researchers to easily develop therapies that target the abnormal characteristics of cancer cells.

HOW DOES CANCER DEVELOP?

Changes in DNA are the cause of cancer. The majority of cancer-causing DNA alterations take place in regions of DNA known as genes. These modifications are also known as genetic modifications. Genes involved in normal cell growth become oncogenes as a result of DNA alteration.
Damage to DNA induced by toxic compounds in the environment, such as the chemical in cigarette smoke and UV rays from the sun, can cause genetic alterations that cause cancer.
Each person’s cancer is made up of a unique set of genetic alterations. Additional alterations will occur as the malignancy progresses. Proto-oncogenes, tumor suppressor genes, and DNA repair genes are among the genes affected by genetic alterations that contribute to cancer. These changes are commonly referred to as cancer’s “drivers”.
?     Normal cell growth and division are aided by proto-oncogenes. These genes can become cancer-causing genes(or Oncogenes) when they are changed or become more active than normal, allowing cells to grow and survive when they shouldn't. 
?    Tumor suppressor genes are engaged in cell division and growth control. Certain mutations in tumor suppressor genes can cause cells to divide uncontrollably.
?    DNA repair genes are responsible for a variety of mechanisms, including the detection and removal of DNA lesions, DNA damage tolerance, and protection from incorporation mistakes during DNA replication or DNA repair.

TYPES OF CANCER

Cancers are classified according to the type of cell that caused them, such as epithelial or squamous cell cancers.
Here are some cancer types that start in specific type of cells.

1.    Carcinoma: 
The most common type of cancer is Carcinoma. Epithelial cells, which cover the interior and exterior surfaces of the body, are the cells that develop Carcinoma. Epithelial cells come in a variety of shapes sizes, and when observed under a microscope, they often have a column-like appearance.
Carcinomas that begin in distinct epithelial cell types have specific names:
(i) Adenocarcinoma- It is a type of cancer that develops in epithelial cells that create mucus or fluids. Glandular tissues are known as epithelial tissues containing this type of epithelial cells.
Adenocarcinomas are the most common malignancies of the breast, colon and prostate.

(ii) Basal cell Carcinoma- It is a type of skin cancer that starts in the lower basal (base) layer of the epidermis, or outer layer of the skin.

(iii) Squamous cell Carcinoma- It is a type of skin cancer that develops in squamous cells , which are epithelial cells found immediately beneath the skin’s surface. When seen under a microscope, squamous cells seem flat, like fish scales. Epidermoid carcinomas are another name for squamous cell carcinomas.

(iv) Transitional cell Carcinoma- Transitional cell Carcinoma is a cancer that develops in the transitional epithelium, or urothelium, a type of epithelial tissue. The linings of the bladder, ureters, and part of the kidneys(renal pelvis), as well as few other organs, are made up of numerous layers of epithelial cells that can get bigger and smaller.

2.    Sarcoma: Sarcoma are malignancies that start in the bone and spread to the soft tissues, such as muscle, fat, blood vessels, lymph vessels, and fibrous tissue(such as tendons and ligaments). The most prevalent type of cancer of the bones is Osteosarcoma.

3.    Leukemia: It is a type of cancer that starts in teh bone marrow’s blood forming tissue. Solid tumours are not formed by these cancers. Instead, abnormal white blood cells (leukamia cells and leukemic blast cells) proliferate and force out normal blood cells in the blood and bone marrow. The body’s ability to get oxygen to it’s tissues, control bleeding, and fight infections can all be hampered by a lack of regular blood cells.
4.    Lymphoma: Lymphoma is a type of cancer that starts in the Lymphocytes. These are white blood cells that fight disease and are part of the immune system. In lymphoma, aberrant cells accumulate in Lymph arteries, and other body organs.
 These are two types of Lymphoma-
(i) Hodgkin lymphoma:
 People suffering from this disease have Reed-Sternberg cells. B cells are used to make these cells.

(ii) Non- Hodgkin lymphoma: 
Lymphocytic malignancies are a wide group of tumours that begin in lymphocytes. Cancers can develop from B cells or T cells and grow swiftly or slowly.

5.    Multiple Myeloma: It is a form of cancer that starts in plasma cells which are an immune cell . Myeloma cells, which are aberrant plasma cells, pile up in the bone marrow and cause tumors in bones all throughout the body. Plasma cell myeloma and Kahler disease are other names for multiple myeloma.

6.    Melanoma: It is cancer that starts in cellsthat develops into melanocytes, specialised cells that produce melanin(the pigment that gives skin it’s color). Melanomas usually develop on the skin, however they can also develop elsewhere. Other pigmented tissues, such as eye, are also affected. 
The greatest treatment, cancer screening and prevention are all available at RG Stone Hospital with well-informed team of experts.