What is Cancer

Cancer has become a dreadful word in most people's mind. There is no scarier diagnosis than that of cancer. Cancer is indeed a serious, life-threatening illness, with an estimated 500, 000 deaths each year.
Cancer Pictures aims to clarify some of the questions you have.

Cancer is a kind of disease where certain cells of the body undergo an out-of-control, abnormal cell growth. Our body is composed of millions of cells, which coordinate in groups, forming body tissues and organs. These cells grow and reproduce constantly, replacing defective or dying cells. In cancer, however, cellular division and reproduction goes uncontrolled and uncoordinated. In some studies, this undesirable process by cancer cells is known to have been caused by a damage or defect in the cell's DNA, the genetic material that defines cellular characteristics and function.
Cancer cells division is much different from normal cells. Normal cells reproduce themselves exactly how they are and stop when they mature at the right time and specialize according to their specific function. Normal cells stick together in the right place and when they are damaged, they self-destruct as new cells begin to proliferate to destroy them. Cancer cell division is a different story. Cancer cells do not stop reproducing, they go on and on without stopping, forming clumps and affecting normal body function. They do not heed and obey any signals from other cells and they do not stick together. They do not specialize and thus they stay immature.
Cancer begins to harm the body when cancer cells reproduce and clump together to form what is called a tumor. The tumor presses, crushes and destroys what is around it, including non-cancerous cells and tissues. This is what defines the many symptoms cancer patients often experience. As the tumor grows, it interferes with the nervous, digestive and circulatory systems, altering normal body functions. A tumor that stays in one part of the body, and which demonstrate limited growth is called benign. Benign cancer is usually non-threatening. However, when cancer cells manage to move and migrate throughout the body, they are called malignant cells. Malignant cancer is more dangerous, as it migrates and invades other body organs. This process, called metastasis, leads to serious conditions which maybe difficult to treat.

Cancer diagnosis is critical in the treatment of cancer. Early detection increases the odds of treatment and survival of patient with cancer. Cancer diagnosis is based on a person's symptoms and the results of his physical examination. Screening tests are also performed which will define what type of cancer he has. Imaging techniques such as CT scans, X-rays, PET scans and ultrasound helps detect where the cancer cells specifically.  Biopsy, the process of extracting cancer cells and examining them under a microscope, is the absolute and most reliable way to diagnose cancer. Altogether, molecular diagnostics, imaging techniques and biopsies are used to diagnose the presence of cancer.

After diagnosis, how far the cancer has spread throughout the body has to be determined. This process is called staging. The most common staging method is called the TNM system, where T (which is scored from 1-4) suggests the size and the extent of the primary tumor, N (0-3) indicates the degree of spread to nearby lymph nodes and M (0-1) suggests the degree to which the cancer has metastasized to other parts of the body. Another simpler categorization of cancer is staging from 0-4. Stage 1 tumors are generally curable while Stage 4 indicates a more grave condition, which is that the tumor is inoperable or that cancer has spread and is untreatable.

The National Cancer Institute has listed the most common cancer types based on cancer diagnosis that has the greatest frequency. To qualify as a common cancer, the estimated annual incidence has to be 35,000 cases or more. The most common types of cancer are skin cancer, breast cancer, lung cancer, prostate cancer and colon cancer. Each of these is discussed further in the next pages of cancer pictures.