"I Am The World's Second Largest Killer; Characterized By Uncontrolled Proliferation Of Cells"

Cancer is the second largest killer disease (the first being coronary heart disease) in the developed countries. It is estimated that cancer accounts for more than 20% of the deaths in United states. Based on the current rate of incidence, it is believed that one in every 3 persons will develop cancer at sometime during his life.

Cancer is characterized by loss of control of cellular growth and development leading to excessive Proliferation and spread of cells. Cancer is derived from a Latin word meaning crab. Uncontrolled growth of cells results in tumors.



The tumors are of two types.

1. Benign tumors : 

They usually grow by expansion and remain encapsulated in a layer of connective tissue. Normally benign tumors are not life-threatening e.g. moles, warts. These types of benign tumors are not considered as cancers.

2. Malignant tumors or cancers :

They are characterized by uncontrolled proliferation and spread of cells to various parts of the body, a process referred to as metastasis. Malignant tumors are invariably life-threatening e.g. lung cancer, leukemia.

About 100 different types of human cancers have been recognized. Cancers arising from epithelial cells are referred to as carcinomas while that from connective tissues are known as sarcomas. 






Causes of cancer

In general, cancers are multifactorial in origin. The causative agents include physical, chemical, genetic and environmental factors. A survey in USA has shown that about 90% of all cancer deaths are due to avoidable factors such as tobacco, pollution, occupation, alcohol and diet.

Most of the cancers are caused by chemical carcinogens, radiation energy and viruses. These agents may damage DNA or interfere with its replication or repair.

Cancer therapy

Chemotherapy, employing certain anticancer drugs, is widely used in the treatment of cancer.

The effectiveness of anticancer drugs is inversely proportional to the size of the tumor i.e. the number of cancer cells. The major limitation of cancer chemotherapy is that the rapidly dividing normal cells are also affected.

Prevention of cancer

In recent years, certain precautionary measures are advocated to prevent or reduce the occurrence of cancer. The most important among them, from the biochemical perspective, are the antioxidants namely vitamin E, beta-carotene, vitamin C and selenium. They prevent the formation or detoxify the existing free radicals (free radicals are known to promote carcinogenesis). In addition, antioxidants stimulate body's immune system, and promote detoxification of various carcinogens.

In general, most of the vegetables and fruits are rich in antioxidants. Their increased consumption advocated to prevent cancer.