Cancer is a malignant and invasive growth or tumor, tending to recur after excision and to metastasize to other sites. Also, any disease characterized by such growths, and any evil condition or thing that spreads destructively.
Is cancer alive? How does it work? What causes it? Is there a cure? Is it contagious?
Cancer is sometimes caused by mutations. A mutation is a natural process that changes a DNA sequence, in most common cases a single base is substituted for another, but sometimes a base is deleted or an extra one is added. Prosperously, the cell is able to repair most of these changes, but…
Let’s go to the beginning. A gene is a segment of DNA, and each gene adds up a specific protein. Many genes control growth factors, cell cycle, and cell division. Signaling pathways and protein complexes regulate genes. As I said before, mutations or point mutations alter the genetic code, which can lead to cancer.
Proto-oncogenes are genes that code for proteins in normal growth or division of cells, and mutations turn those genes to oncogenes, which are cancer – causing genes. These genes produce a protein that can stimulate cells to grow out of control, and develop into a cancer. Still, there are multiple steps that need to occur, so cancer can spread. These steps usually require 10 or more years.
Fortunately, all of us have tumor-suppressor genes; these genes protect the cells from one step on the path to cancer. Tumor-suppressor genes are activated when the DNA is damaged. If this gene is lost, then an oncogene will be activated, but, still one more tumor- suppressor gene is protecting. Both of the tumor-suppressor genes must be knocked out, so that cancer can spread.
You may ask yourself, is it contagious, can it be inherited? Oncogenes can be either hereditary or acquired. When it is hereditary, it requires multiple mutations, and oncogenes are usually dominant. Of color rectal cancers 15% are hereditary, of breast cancer patients 5-10% have strong hereditary disposition. When it is acquired, 15% are linked to viruses, and the rest are from smoking, UV exposure, and aging.
Is there a cure? Cancer is not a death warrant as more than 75% of cancer cases are curable, if detected at early stages. Scientists have identified more than 100 different oncogenes, and understanding these genes opens the door for new cancer treatments in the future.