Cancer is a deadly disease relating to the abnormal growth of human cells. About hundred types of cancer have been identified by physicians.  Skin cancer, Breast cancer, blood cancer, prostate cancer, colon cancer, lymphoma, bone marrow cancer, throat cancer etc are some of them. There are more than 100 types of cancers.

Symptoms vary depending on the type. Abnormal bleeding, a lump, prolonged cough, change in bowel movements, weight loss etc are the common symptoms of cancer. Cancer treatment may include chemotherapy, radiation, and/or surgery. A group of cells in a particular organ starts abnormal growth due to various reasons and slowly invades other organs of the body.  All tumors are not cancerous.

There are benign tumors also. Statistics show that tobacco use is the cause for 22 % of all cancer deaths. Similarly obesity counts for another 10 % of cancer deaths. Changes of the mutations caused without any identifiable reason to the DNA of human cells is the root cause for the formation of cancer. DNA can be considered as a package of several groups of genes, which contains instruction to the cells regarding the functions to be performed by them. They also instruct the cells how to grow and divide. There occur some errors in genes causing stoppage of its normal functions and making them cancerous.

Effect of gene mutations

1. Allow rapid growth: As a result of gene mutation the cell becomes cancerous and starts growing fast by dividing faster.  This creates large number of cancerous cells at a faster rate.
2. No control for the growth of cancerous cells: Normal cells stop growing when enough number of them is formed. But cancerous cells do not have any ability to stop growing. So they multiply and grow continuously at a faster rate.
3. Mutated gene is not repairable: Normally any errors in genes are repaired by DNA. But cancerous cells do not come under the purview of repair by DNA.

Examine how gene mutations are caused?

There are many reasons for the formation of gene mutation in human beings. Two of the most important ones are discussed here.

1. Hereditary gene mutations: A person may be born with inherited genetic gene mutation. This type of mutations actually accounts for a small percent of the cancerous mutations that are taking place in human beings.
2. Gene mutations occurring after birth: Most of the gene mutations are not inherited as they are formed after the birth of the person. Factors like smoking, viruses, radiation, carcinogens, hormones obesity, lack of exercise etc are some of the caused that results in gene mutations after birth.