Cancer is the major cause for the most of the death all around the world. According to the World Health Organization (WHO) cancer is the second most cause of the deaths in 2013 and 2015, which was about 7.6 million and 8.8 million deaths, respectively, and it is estimated that, in 2030 the data will be reached to 11.5 million deaths. In India, the premier research organization, Indian Council of Medical Research (ICMR), also predicted that more than 17.
3 lakh new cases of cancer and 8.8 lakh deaths will be present due to the disease by 2020. Cancer is a disease occurs due to the discrepancy in the cell division and cell death processes which leads overcrowding of the cells in the specific area and hence, invades into the surrounding tissues (metastasis) and affected their functioning. The metastatic nature of these cells may lead to morbidity of the host, if remains untreated. The number of cells is continuously increased by the cell division, known as mitosis.
In normal physiology, cells divide to compensate the tissue damage and replace the old dying cells with newly formed cells and then the division will stop in the controlling manner. The process decides the organization, size and structure of every tissue and organ in the appropriate manner. Sometimes, the controlling ability of the some cells may have lost due to some factors, and do not divide and grow in the proper mechanism. Thus, these cells may be converted into the large size tumor structure or neoplasm due to the continuous division of the cells without any control.
The neoplasm is the group of similar cells represents the pathological condition of cell growth leads to production of large number of enlarged cells with the enhanced metabolic activity. The neoplasm may be harmless or harmful on the basis of their location and rate of cell growth. The harmless or stagnant neoplasm is known as the benign tumor and may lead to very slow cell growth and does not invade other surrounding tissue, means remains localized. Hence, the patients may not suffer with any serious disorders. The other type of neoplasm is harmful or lethal to the patient because of the rate of cell division is very high and the cells invade and spread all around the tissue and hence affect the proper functioning of that tissue. These types of neoplasm are known as malignant tumor and urgently require an effective treatment or therapy (Ziegler and Buonaguro, 2008). Cancer term is derived from the latin term crab because of the cancer cells invade and attached with the surrounding tissues in the stubborn manner, like the crab.
Tumor or neoplasm cells proliferate and develop due to some genetic mutations present in the normal population of cells. The cells divide rapidly to produce a large number of highly proliferated cells and the condition is called hyperplasia. Some other mutations in the one of these cells may also lead to loss of control on the proper cell division and development process. The cells are characterized by their specific shape and size due to the abnormality present in the cells, the condition is known as dysplasia. The mutation may be occurred due to various external factors (infectious organisms, tobacco, radiation and chemicals) and internal factors (hormones, inherited mutations, mutations that occur from metabolism and immune conditions).
These causal factors may act together or in sequence to initiate or promote the development of cancer. The further mutation changes in the cell causes the tumor malignancy and the cells to enter into the liquid connective tissues i.e., blood or lymph. These malignant cells are distributed throughout the body and metastasis also spread in all over the body and affect the normal functioning of the organs. Some cells are differentiated and showing similarity with the origin cells functioning while the other types of undifferentiated cells are differ in nature as the origin cells. The undifferentiated cells are also known as the anaplastic tumors, exhibit very rapid and destructive growth of the cells and a phenomenon, called pleomorphism (cells at different stages of the life cycle).
The shape and size of the cells are variable in nature, some cells are very large while the others are small and primitive. The normal cells have smaller nuclear cytoplasmic ratio (1:4 or 1:6) while these anaplastic cells have higher ratio (1:1) and nucleus of the cells are large, stained easily so they are called hyperchromatic cells. Their chromatin is usually coarsely clumped and distributed along with the nuclear membrane.
The cells undergo in the cell division process and produce different types of mitotic spindles i.e. tripolar, quadripolar or multipolar. Some of the cells are also classified as the intermediate or moderately differentiated cells due to the presence of some intermittent changes.