Cancer is the name for diseases in which the body’s cells become abnormal and divide without control. Cancer is not just one disease, but a large group of almost 100 diseases. Its two main characteristics are uncontrolled growth of the cells in the human body and the ability of these cells to migrate from the original site and spread to distant sites. If the spread is not controlled, cancer can result in death.
Cancer cells may invade nearby tissues. And they may spread through the bloodstream and lymphatic system to other parts of the body.
Thirty-five percent of all cancers are due to dietary causes. Excessive intake of fat leading to obesity has been associated with cancers of the breast, colon, rectum, pancreas, prostate, gall bladder, ovaries, and uterus.
Excessive consumption of alcohol is a risk factor in certain cancers, such as liver cancer. Alcohol, in combination with tobacco, significantly increases the chances that an individual will develop mouth, pharynx, larynx, and esophageal cancers.
In the last 20 years, scientists have obtained evidence to show that approximately 15% of the world’s cancer deaths can be traced to viruses, bacteria, or parasites.
Radiation is believed to cause 1-2% of all cancer deaths. Ultra-violet radiation from the sun accounts for a majority of melanoma deaths. Other sources of radiation are x rays, radon gas, and ionizing radiation from nuclear material.
According to estimates of the American Cancer Society (ACS), approximately 40% of cancer deaths in 1998 were due to tobacco and excessive alcohol use. An additional one-third of the deaths were related to diet and nutrition. Many of the one million skin cancers diagnosed in 1998 were due to over-exposure to ultraviolet light from the sun’s rays.
Recently, scientists have also shown that second-hand smoke (or passive smoking) can increase one’s risk of developing cancer.
Sexual and reproductive behavior
The human papillomavirus, which is sexually transmitted, has been shown to cause cancer of the cervix. Having too many sex partners and becoming sexually active early has been shown to increase one’s chances of contracting this disease. In
addition, it has also been shown that women who don’t have children or have children late in life have an increased risk for both ovarian and breast cancer.
Certain cancers like breast, colon, ovarian, and uterine cancer recur generation after generation in some families. A few cancers, such as the eye cancer “retinoblastoma,” a type of colon cancer, and a type of breast cancer known as “early-onset breast cancer,” have been shown to be linked to certain genes that can be tracked within a family. It is therefore possible that inheriting particular genes makes a person susceptible to certain cancers.
There is evidence to prove that certain occupational hazards account for 4% of all cancer deaths. For example, asbestos workers have an increased incidence of lung cancer. Similarly, a higher likelihood of getting bladder cancer is associated with dye, rubber and gas workers; skin and lung cancer with smelters, gold miners and arsenic workers; leukemia with glue and varnish workers; liver cancer with PVC manufacturers; and lung, bone and bone marrow cancer with radiologists and uranium miners.
Several studies have shown that there is a well-established link between asbestos and cancer. Chlorination of water may account for a small rise in cancer risk. However, the main danger from pollution occurs when dangerous chemicals from the industries escape into the surrounding environment. It has been estimated that 1% of cancer deaths are due to air, land, and water pollution.
Types of Treatment
Chemotherapy: The treatment of disease by the use of chemical substances, especially the treatment of cancer by cytotoxic and other drugs.
Immunotherapy: The prevention or treatment of disease with substances that stimulate the immune response.
Biological Therapies for Cancer: These are treatments that act on cell processes. They may stop cancer cells from dividing and growing, seek out cancer cells and kill them or encourage the immune system to attack cancer cells
Radiation Therapy for Cancer: The use of high-energy rays to damage cancer cells, stopping them from growing and dividing.
Targeted Cancer Therapies: This is a type of treatment that targets a cancer’s specific genes, proteins, or the tissue environment that contributes to cancer growth and survival.