Cancer is widely prevalent in today’s times. Largely because of our lifestyles, the number of cases being reported are increasing at a fast pace. It is important to understand the term cancer before discussing any other issue.
Cancer is an umbrella term that is used for diseases in which the abnormal cells in a body divide and invade other tissues.
How cancer starts?
Our bodies are made of trillions of cells. Normal cells have a life span, they experience growth, division and death depending on our age. Normal cells tend to experience division faster in the early years as compared to when we are adults when cells divide to replace the dead or the injured cells.
In the case of cancer, the cells do not follow a normal pattern of growth and start to grow randomly. The cells that are supposed to die do not die, continue to grow and even form new cells. Cancerous cells have the potential of invading other tissues which normal cells do not do.
Cancer cells are formed when the DNA (deoxyribonucleic acid) present in the cells gets damaged. In the case of a normal cell, a damaged DNA is repaired or the cell dies while in case of cancerous cells, the damaged DNA is neither repaired and nor does the cell die. The new cells formed from this cell with damaged DNA have abnormal DNA as in the case of the source.
DNA can be damaged for two reasons – people inheriting abnormal DNA and the environment (smoking, exposure to sun). It is not possible to determine the exact reasons that led to cancer in a patient.
While some cancers may form tumors other may involve the blood and organs that are involved in formation of blood.
How does it spread?
Cancer cells have the ability to travel to different parts of the body. The cancer cells use the blood stream or the lymph vessels to travel to new locations. In this new location they start to grow, form new tumors and in the course of time replacing normal tissue. Metastasis is the term used for describing the process of spread of cancer.
All tumors are not cancer
It is important to remember, that all tumors are not cancerous. Non-cancerous tumors are termed as benign while the ones that are capable of spreading are termed as malignant. Benign tumors come with their own share of problems – they tend to grow large and press on healthy organs. Usually these are not life threatening.
How common is cancer?
There are millions of people who are living with the disease or have dealt with it at some stage of their lives. Number of factors play an important role in determining
a person’s susceptibility to cancer which will be discussed later. Screening tests are available for early detection increasing the chances of survival. It is estimated that 50% men and 75% women in the US will develop cancer during their life time. With respect to India, the total number of cases are expected to rise from 979,786 cases in the year 2010 to 1,148,757 cases in the year 2020. Some important figures with respect to different types of cancers with specifically for India are:
2010 |
2020
|
|
Cancers related to digestive systems |
107,030 |
86,606
|
Cancers related to head and neck |
122,643 |
53,148
|
Gynecological related cancers |
153,850 |
182,602
|
Breast cancer |
100,000+
|
References:
http://www.cancer.org/cancer/cancerbasics/what-is-
http://www.ncbi.nlm.nih.gov/pubmed/21133622
http://www.cancer.org/cancer/cancerbasics/what-is-cancer