Cancer Types by Site
Medical professionals frequently refer to cancers based on their histological type. However, the general public is more familiar with cancer names based on their primary sites. The most common sites in which cancer develops include:
Compared with those based on histological type, cancers named after the primary site may not be as accurate. Take lung cancer for example; the name does not specify the type of tissue involved. It simply indicates where the cancer is located. In fact, depending on how the cells look under a microscope, there are two major types of lung cancer: non-small cell lung cancer and small cell lung cancer. Non-small cell lung cancer can be further divided into various types named for the type of cells in which the cancer develops, typically: squamous cell carcinoma, adenocarcinoma, and large cell carcinoma.
However, it's important to know that cancer can be classified either by the cell type or its primary site. Saying that a woman has uterine carcinoma or uterine cancer is the same thing as saying that she has cancer (or carcinoma) of the uterus.
Following are some examples of common types of cancers named for their primary site.
There are three primary types of skin cancer: basal cell, squamous cell, and melanoma. These cancers are derived from the epidermal layers with the same names. Melanomas are derived from the melanocytes, or pigment cells, in the deepest level of the epidermis.
Basal cell and squamous cell cancers usually occur on parts of the body exposed to the sun, such as the face, ears, and extremities. These cancers are highly curable, especially if detected and treated early. Melanomas, which form dark moles that spread over the surface of the skin, are more lethal because they metastasize very quickly.
Lung cancer is very difficult to detect at an early stage because the symptoms often do not appear until the disease has advanced. The symptoms include persistent cough, sputum streaked with blood, chest pain, and repeated attacks of pneumonia or bronchitis.
It has been estimated that in the U.S., about 1 in 8 women will eventually develop breast cancer in her lifetime. Most breast cancers are ductal carcinomas. Women most likely to develop the disease are those over the age of 50; those who have already had cancer in one breast; those whose mother or sister had breast cancer; those who never had children; and those who had their first child after the age of 30. Other risk factors include obesity, a high-fat diet, early menarche (age menstruation begins) and late menopause (age menstruation ceases).
Monthly breast self-examination is recommended as a way to detect breast cancer early. Most of the lumps found in the breasts are not cancerous, but women should see their physicians to find out for sure. The American Cancer Society also recommends periodic mammograms (or breast X-rays) for all women over the age of 40 as well as physical examinations of the breast by a physician for all women over the age of 20, even if they have no symptoms of breast cancer.
Cancer of the prostate is found mainly in older men. As men age, the prostate may enlarge and block the urethra or bladder. This may cause difficulty in urination or interfere with sexual functions. This condition is called benign prostatic hypertrophy (BPH). Although BPH is not cancerous, surgery may be needed to correct it. The symptoms of BPH, or of other problems in the prostate, may be similar to symptoms for prostate cancer.
Individuals should consult a physician if any of the following symptoms appear: weak or interrupted flow of urine; urinating often (especially at night); difficulty urinating; pain or burning during urination; blood in the urine; or nagging pain in the back, hips, or pelvis. Often there are no symptoms of early cancer of the prostate.
Colon and Rectum
Of the cancers that affect the large intestine, about 70 percent occur in the colon and about 30 percent in the rectum. These cancers are the third most common cancers overall. Symptoms include blood in the stool, which can be tested for by a simple fecal occult blood test, or a change in bowel habits, such as severe constipation or diarrhea.
Uterus (Corpus Uteri)
The uterus is the sac in a woman's pelvis which allows a baby to develop from a fertilized egg and protects it until birth.
Cancer of the uterus is the most common gynecologic malignancy. This cancer occurs infrequently in women under 40 years of age. It occurs most frequently after the age of 60. The presenting symptom is usually abnormal uterine bleeding. An endometrial biopsy or D&C is often performed to confirm the diagnosis.
Currently, there has been little insight into the exact causes for uterine cancer. However, 10-25 percent of malignancies occur in women who received pelvic radiation five to 25 years earlier for benign bleeding. As in other cancers of its type, risk factors for uterine cancer include diabetes, hypertension, obesity, and improper estrogen levels.