Learn About the Most Common Types of Cancer: Types, Risk Factors, Causes, Symptoms and Treatments
Non-Melanoma Skin Cancer
Non-melanoma skin cancers affected more than 1 million people in 2009. Interestingly, they caused fewer than 1,000 deaths. Examples of non-melanoma skin cancers include squamous cell skin cancer and basal cell skin cancer. The American Cancer Society estimates that 20 percent of skin cancer cases involve squamous cell carcinoma. These cancers appear on areas of the body that receive a great deal of sun exposure, particularly the ears, face, lips, neck and back of the hands. These cancers also invade fatty tissues below the skin, making it easier for the cancer to spread to the lymph nodes.
Basal cell cancer represents approximately 80 percent of skin cancer cases. This cancer also affects skin that receives sun exposure. This cancer used to affect older people, but it now affects young people who spend more time in the sun without protective coverings. This cancer rarely spreads to the lymph nodes because it grows very slowly. Basal cell skin cancer tends to recur in the same area even after treatment. Other types of non-melanoma skin cancer include keratoaconthomas, cutaneous lymphoma, Merkel cell carcinoma and some types of sarcomas.
219,400 cases of lung cancer occurred in 2009, with 159,390 deaths. This type of cancer occurs when the cells in the lungs grow out of control. These malignant cells do not perform like normal cells, so they do not turn into healthy lung tissue. This causes tumors and reduces lung function. Primary lung cancer actually starts in the lungs, while secondary lung cancer spreads to the lungs from a primary cancer site elsewhere in the body. This cancer affects men slightly more than women.
Medical professionals classify this type of cancer as non-small cell lung cancer or small cell lung cancer. Non-small cell lung cancers are more common than small cell forms of the disease. Medical professionals further classify non-small cell lung cancer as squamous cell carcinoma, large-cell undifferentiated carcinoma, adenocarcinoma and bronchioalveolar carcinoma.
Breast cancer occurs predominantly in women, although it is possible for men to get breast cancer. In 2009, there were 192,370 cases of breast cancer in women and only 1,910 cases of breast cancer in men. The National Cancer Institute estimates 40,170 deaths in women affected by breast cancer and 440 men affected by this cancer. This type of cancer occurs when breast cells divide and grow out of control. The Susan G. Komen Foundation estimates that 85 percent of breast cancer cases start in the mammary ducts and 15 percent begin in the lobules of the breasts. Some breast tumors grow rapidly, but the majority of breast cancers grow slowly.
Doctors identify breast cancers as invasive breast cancers or ductal carcinoma in situ. Invasive breast cancers occur when malignant cells break into breast tissue from the ducts or lobules. The cancer spreads to lymph nodes and other organs as it advances. Ductal carincoma in situ occurs when malignant cells grow in the milk ducts but do not spread to other tissues. This type of cancer can develop into invasive cancer, so early treatment is important.
The prostate is a firm gland located at the neck of urethra in males. It produces a secretion contained in seminal fluid. In 2009, there were 192,280 cases of prostate cancer in 2009, with 27,360 deaths from this disease. Researchers do not know the exact cause of prostate cancer, but several factors increase the risk for this disease. They include obesity, older age (over 65) and family history of prostate cancer. Black men also have a great risk for developing this disease.
This type of cancer causes several complications. If the cancer spreads, it can affect other organs or travel through the bloodstream to the bones. This makes it more difficult to treat than when the cancer remains confined to the prostate. Because the prostate gland affects urination, this condition can also cause incontinence. Mild incontinence may not require medical treatment, but more serious cases require medication or surgery. Prostate cancer can also cause erectile dysfunction.
Cancers of the colon and rectum occurred in 146,970 cases, with a total of 49,920 deaths, in 2009. More common in people over the age of 50, the risk for this cancer also increases with a high-fat diet, the presence of colon polyps, Crohn’s disease, a family history of colorectal cancers and ulcerative colitis. These cancers usually start out as polyps, according to the American Cancer Society. ACS also reports that adenocarcinomas make up over 95 percent of all colorectal cancer cases.
Doctors use staging to indicate how far this type of cancer has spread. Each stage receives a label from I through IV, with the lowest numbers meaning that the cancer has spread less than cancers with the highest numbers. Doctors also use grading to describe what the cancer tissue looks like. Low-grade colorectal cancers look more like normal tissue than high-grade cancers. High-grade cancers have a lower survival rate than low-grade cancers.
The bladder is an organ that stores urine before it excretes the urine via the urethra. Bladder cancer often begins in the cells in the lining of the bladder and grows into tumors. There is no clear cause for this type of cancer, but several risk factors increase the chance that you will develop the disease. These risk factors include gender (men have bladder cancer more than women), tobacco use, increasing age, chemical exposure and chronic bladder inflammation. Caucasian race also increases the risk of bladder cancer.
The Skin Cancer Foundation Reports that melanoma is the most serious form of cancer. Luckily, it is almost 100 percent curable if diagnosed and treated early. Melanoma tumors begin in melanocytes, which produce the melanin that provides color for the hair, eyes and skin. Melanomas range in color from black and brown to blue and white. Excessive sun exposure is one of the major risks for melanoma. This cancer also affects people with a family history of melanoma and those who have moles on their skin.
One way to recognize melanoma early is to use the ABCDE method of melanoma detection. If you have a mole or brown spot on the skin, check it using this method. A stands for asymmetry; if you drew a line through the mole, the two halves would not be the same size. B stands for border; look for uneven borders with notched edges. C stands for color. If the mole has several different colors, this can be a warning sign of melanoma. D stands for diameter. Melanomas usually exceed the size of a pencil eraser. E stands for evolving. If the spot changes in size, color or shape, this makes it more likely that it is cancerous.
Non-Hodgkin’s lymphoma starts in the lymphatic system. Normally, the lymphatic system helps the body fight infection. In cases of Non-Hodgkin’s lymphoma, white blood cells develop into tumors. This type of lymphoma occurs more frequently than Hodgkin’s disease, which is another type of lymphoma. This disease can affect the B cells or the T cells. B cells produce antibodies to neutralize infectious organisms. T cells kill infectious organisms directly. B cell lymphoma occurs more often than T cell lymphoma.
Several factors increase the risk of developing non-Hodgkin’s lymphoma. If you take medications that suppress the function of the immune system, the body is unable to fight off infections like it should. HIV, Epstein-Barr virus and hepatitis C increase the risk of this cancer, as well as a bacteria known as Helicobacter pylori. Exposure to chemicals that kill insects and weeds also increases the risk for this disease.
The kidneys filter waste from the blood and produce urine. These organs also maintain normal levels of electrolytes (potassium, salt, chloride and bicarbonate) in the body. MayoClinic.com explains that the most common type of kidney cancer is renal cell carcinoma. Other types of kidney cancer include Wilms’ tumor and transitional cell carcinoma. In its early stages, kidney cancer does not usually cause any symptoms. As the cancer progresses, it may cause blood in the urine, weight loss, fever, fatigue and flank pain (pain below the ribs). This type of cancer occurs when the DNA in the kidney cells mutates. This type of mutation instructs the cells to grow more rapidly than normal, which results in the formation of tumors. If cells break off of the tumor, they can spread to other body parts. Scientists do not know what causes the DNA changes responsible for kidney cancer.
Several factors increase the risk of kidney cancer. Males have kidney cancer more often than females. People also have a greater risk for kidney cancer as they age. Industrial chemicals, such as cadmium, increase the risk of kidney cancer in those who receive regular exposure. Other risk factors for kidney cancer include obesity, high blood pressure, smoking and the presence of Von Hippel-Lindau disease. Doctors use cryotherapy, radiation, chemotherapy and surgery to treat kidney cancer. The treatment used depends on the type of cancer and how far it has spread.
Leukemia, or cancer of the white blood cells, make it difficult for the immune system to protect the body from disease. As the bone marrow produces more and more abnormal cells, they enter the bloodstream. This leads to interference with the production of platelets and red blood cells. KidsHealth from Nemours estimates that leukemia accounts for 25 percent of all childhood cancer. In children, doctors classify leukemia as rapidly-developed and chronic. The rapidly-developing forms of leukemia include acute myelogenous leukemia and acute lymphocytic leukemia. AML affects the myelocytes, while ALL affects the lymphocytes.
Genetic diseases, like Down syndrome, neurofibromatosis, Fanconi’s anemia and Fraumeni syndrome, increase the risk for leukemia. Immunosuppressant drugs, radiation therapy and chemotherapy drugs also increase the risk for leukemia. Symptoms of leukemia include fatigue, loss of appetite, pain in the joints, swollen lymph nodes and pain in the bones. In some cases, leukemia causes vision disturbances, headaches, balance problems and seizures. Treatment for leukemia depends on the type of leukemia present and the patient’s white blood cell count.
National Cancer Institute: Common Cancer Types
American Cancer Society: Skin Cancer Facts
Susan G. Komen Foundation: Understanding Breast Cancer Guide
American Cancer Society: All About Colon and Rectum Cancer
The Skin Cancer Foundation: Melanoma
MayoClinic.com: Kidney Cancer
KidsHealth from Nemours: Childhood Cancer: Leukemia