Introduction
In 1971, President Richard Nixon signed the National Cancer Act, committing federal resources to finding a cure for cancer. More than 35 years later, cancer is still the second leading cause of death in the United States. According to the American Cancer Society, 7.6 million people have died in the world from cancer since cancer was discovered. Currently cancer accounts for 1 out 4 deaths in America. Nevertheless there is good news to report. The rate of cancer-related deaths has been significantly reduced, according to the National Cancer Institute. And, new treatments are being introduced all the time.
What is it?
Cancer is a group of diseases characterized by uncontrolled growth or spread of abnormal cells. The abnormal cells can form a mass, or a tumor. Tumors can either be "benign" (not harmful) or "malignant" (cancerous). If the cells grow out of control but are not able to invade other tissues, the tumor is benign. Cells that grow out of control, invade other tissues, and spread to other parts of the body represent malignant tumors (cancer). Malignant tumors can spread to other parts of the body by shedding cells into the blood or lymph system.
Cancers are classified according to their origin and the type of tissue involved. Types of cancers include:
- Carcinomas, which begin in tissues like the skin, mucous membranes, stomach, or intestines.This group includes the most common forms of cancer such as breast, prostate, colon, and lung cancers.
- Sarcomas, which originate in muscle or connective tissues such as bone, cartilage, and fat.
- Leukemias, which involve blood cells.
- Lymphomas, which affect lymph nodes throughout the body.
- Blastomas, which originate from immature embryonic cells
Malignant tumors are usually named using -carcinoma, -sarcoma or -blastoma added to the end of the Latin or Greek word for the organ of origin as the root. For instance, adeno- is the Greek word that relates to glandular tissue, therefore a malignant cancer of a glandular tissue is adenocarcinoma. From this you can see that the beginning portion of the word is adeno- and the ending portion is carcinoma.
Benign tumors are also named adding -oma to the end of the Latin or Greek word for with the organ involved. For instance, a benign tumor of the glandular tissue is an adenoma.
What causes it?
The cause of cancer is not clearly known. However, at its most basic level, cancer is a disease of the genes. Genes are the blueprints for our growth and development. Every cell in our body contains our genes, or genetic material. These genes program the cell to divide at a certain rate. When changes to the gene occur, it is called a genetic mutation. These mutations lead to inappropriate growth and division of the cell, which can sometimes cause cancer.
Genetic mutations, or faulty genes, can be inherited or the result of an exposure to carcinogens, substances that can cause genetic mutations. Carcinogens may include:
- certain medications
- chemicals
- hormones
- viruses and other infectious angents
- ultraviolet light
- tobacco smoke
- radiation
Who has it?
The National Cancer Institute estimates that approximately 10.8 million Americans have cancer or a history of cancer. One-half of American men and one-third of American women will develop cancer during their lifetimes. More than 1.4 million new cases of cancer will be diagnosed this year, which does not account for the nearly 1 million new cases of basal skin cancer that will also be diagnosed this year.
Cancer is the second leading cause of death in the U.S. with almost 560,000 deaths annually--more than 1,500 people a day. Cancer causes one in four deaths in this country. Cancer rates are approximately 16 percent higher among African-American men than Caucasian men. Death rates from all cancers combined peaked in 1990 for men and in 1991 for females. Between 1990 and 2003 death rates from cancer decreased by 16.3 percent for men and between 1991 and 2003 death rates have decreased by 8.5% for females.
What are the risk factors?
Risk factors are characteristics that increase your chance for developing a condition. Exposure to certain substances in the environment may increase the risk of cancer. In fact, many cancers can be prevented by:
- not using any tobacco products
- eating a proper diet
- avoiding the overexposure to the sun or ultraviolet light (as also found in tanning beds)
|
|
Other risk factors are those that were discussed previously as contributing to the cause of cancer. Other risk factors that cannot be controlled include increasing age and family history. For example, women with a mother, sister, or daughter who has had breast cancer have a higher risk of getting the disease. Prostate cancer also appears to have a hereditary link.
What are the symptoms?
Symptoms vary greatly with the location and type of cancer. If you notice one of the early warning signs, consult your doctor immediately. Many cancers can be cured if caught early.
Some of the early warning signs in adults include:
- a change in bowel or bladder habits
- a sore throat that does not heal
- unusual bleeding or discharge
- thickening or a lump in the breast or other part of the body
- indigestion or difficulty swallowing
- an obvious change in an existing wart or mole
- a nagging cough or hoarseness
- unexplained weight loss
- persistent fever, chills, or night sweats
Some early warning signs in children include:
- continued, unexplained weight loss
- headaches with vomiting in the morning
- increased swelling or persistent pain in bones or joints
- lump or mass in abdomen, neck, or elsewhere
- development of whitish appearance in the pupil of the eye
- recurrent fevers not caused by infections
- excessive bruising or bleeding
- noticeable paleness or prolonged tiredness
Early Detection Plays a Crucial Role:
Fortunately, screening tests can detect more than one-half of all new cancers. These include cancers that affect the:
|
|
Early detection means early treatment, and early treatment means increased survival rates. For example, 100 percent of women who are diagnosed with breast cancer at an early stage live at least five years after remission. If breast cancer is detected after it has spread, the rate decreases to only 20 percent.
If all Americans participated in regular detection programs, the survival rate of many cancers could reach 95 percent, according to the American Cancer Society.
Once you are diagnosed with cancer, your doctor will use a staging system to determine how advanced the cancer is at the time of diagnosis. He/She will measure the cancer's development through a course of treatment. Staging systems can differ according to the type of cancer.
One type of staging involves a "TNM" rating:
- A "T" refers to the size of the tumor. Tumors are graded on a scale of one to four, with four being the most advanced.
- An "N" refers to how much the cancer has affected the lymph nodes, which exist throughout the body. Lymph node involvement is graded on a scale of zero to three, with three having the most lymph node involvement.
- An "M" rating is used to identify if the cancer has spread, which is referred to as "metastasized." Metastases are assigned a zero if the tumor has not spread or a one if it has.
An adittional staging system uses the Roman numerals I to IV. Stage I cancers are usually small and curable and stage IV cancers are the most advanced and most difficult to successfully treat.
How is it treated?
Treatment may provide a cure, relieve discomfort, or serve as a preventive measure against recurring tumors. There are three types of treatments most commonly used for cancer. Sometimes these treatments are used individually and other times they are used in combination.
- Surgery - the oldest and most commonly used method of treatment for solid tumors. The concept is simple: cut the cancer out of the body. Surgery also has an important role in making a diagnosis and determining the severity of the disease.In theory, any cancer not involving the blood could be cured if entirely surgically removed, however this is not always possible. When cancers metastasize to other regions of the body their complete removal by surgery is nearly impossible. Examples of surgery include mastectomy for breast cancer and prostatectomy for prostate cancer. The goal of the surgery may be removal of the entire organ or just the tumor. However, a single cancer cell is invisible to the naked eye and has the ability to re-grow an entire tumor, a process call recurrence.
- Radiation - the use of high-energy X-rays and gamma rays to destroy tumors. Therapeutic doses of radiation are normally built up through a series of treatments that take place over several weeks or by having radioactive implants placed directly in the tumor. Radiation can destroy cells that were not visible to the surgeon when a tumor was removed.Radiation can also be used to slow the spread of cancer and to offer relief from pain in conditions such as bone cancer.Although radiation can damage both tumor cells and normal cells, most normal cells can recover from the effects of radiation and function properly. The goal of radiation is to harm as many tumor cells as possible while limiting the negative effects to healthy tissue.
- Chemotherapy - the use of chemicals or medications to treat cancer. The drugs used in chemotherapy interfere with cancer cells' ability to divide and reproduce. While the ultimate goal of chemotherapy is to destroy malignant cells without harming normal cells, selectivity is difficult because only subtle differences exist between normal and cancerous cells. Treatment may be deemed successful if normal cells are able to recover, and tumor cells are destroyed. Chemotherapy is the main treatment for metastatic cancer.Chemotherapy often works well on metastatic cancers because they are growing rapidly. Therefore, by inhibiting division and reproduction of the tumor cells, chemotherapy can oftentimes be the treatment of choice to provide a successful outcome.
Your doctor will recommend the best option for you depending on the following:
- your type of cancer
- the stage of your cancer
- your age
- medical history
- general health
Drug classes used to treat Cancer
- Alkylating Agents
- Anti-estrogens
- Antimetabolites
- Antineoplastic Antibiotics
- Antineoplastic Hormones
- Interleukins
- Mitotic Inhibitators
What is on the horizon?
Researchers are currently studying more than 300 new drugs for treating or preventing cancer and thousands of trials are ongoing that involve other cancer related issues. Moreover, several drugs that are used today for other health conditions are currently being studied for their potential role in the prevention and treatment of certain cancers.
In addition to new drugs, the following therapies are under study:
- Gene therapy - an area of interest to many researchers. The idea here would be to replace the defective genes in cancer cells with normal, healthy genes, thereby correcting the cells' overactive replication problem. The challenge is finding a way to get the healthy genes into the cancer cells.
- Cancer vaccines - to treat existing cancers by teaching the body's immune system to target and destroy cancer cells.
- Antiangiogenic therapy - Angiogenesis is the rapid formation of new capillaries for transporting blood to the tissues. Under normal circumstances, this process is rare and lasts only a short time. Tumors have been known to stimulate angiogenesis when they spread into tissues other than the ones where they originated. By preventing the formation of new capillaries, scientists hope to deprive the tumor of its blood supply, and therefore, its ability to spread.
- Laser therapy- Lasers are small beams of concentrated light. They are currently being used for the treatment of small cancers on the skin. Lasers can be used alone or in combination with other treatments. Advances in this technology may lead to further uses.
