2. Review of Literature2.1 Cancer: OverviewCancer is one of the most life-threatening diseases that forms a major global health problem and is the leading cause of death especially in developing countries. Despite enormous advancements in medicine and modern biology, including sequencing of the human genome and the identification of various factors that causes certain cancers; its management and therapies have thrown open bigger challenges.
Thus, the burden of cancer is on the rise, such that prevention, if not cure of cancer is far from satisfactory. An in-depth knowledge of the genesis at the cellular and molecular level is critical for developing global strategies for prevention, control and treatment of cancers. Simply, cancer is our own cells that just grow abnormally and in uncontrolled manner. Cancer occurs when normal cells undergo a transformation whereby growing and multiplying without any control. As the cells multiply, they form an area of abnormal cells known as a tumor. As more and more cells are produced, the tumor increases in size. Tumors overwhelm surrounding tissues by invading their space and taking the oxygen and nutrients they need to survive and function.
Tumors are cancerous only if they are malignant. Due to their uncontrolled growth, they encroach on and invade neighboring tissues. Malignant tumors may also travel to remote organs via the bloodstream or the lymphatic system. This process of invading and spreading to other organs is called metastasis (Figure 2.
1). Bladder Cancer cells morphologically differ from normal urothelium by having an increased number of epithelial cell layers with papillary folding of the mucosa, loss of cell polarity, abnormal cell maturation from basal to superficial layers, increased nuclear-cytoplasmic ratio, prominent nucleoli, clumping of chromatin, and increased number of mitosis (Talmadge and Fidler, 2010). 2.
2 Bladder: The bladder is a hollow organ in the lower abdomen (pelvis) (Figure 2.2). It collects and stores urine produced by the kidneys.
As it fills with urine, the muscular wall of the bladder stretches and the bladder gets larger. When the bladder reaches its capacity of urine, the bladder wall contracts, although adults have voluntary control over the timing of this contraction. At the same time, a urinary control muscle (sphincter) in the urethra relaxes.
The urine is then expelled from the bladder. The urine flows through a narrow tube called the urethra and leaves the body. This process is called urination or micturition.