THIS CANCER IS CHARACTERIZED BY ABNORMAL GROWTH OF CELLS IN THE UTERUS

Uterine Cancer

Introduction

A disease characterized by the abnormal growth of cells in the uterus. Cancers affecting the lining of the uterus (endometrium) are the most common cancers of the female reproductive tract. Other uterine cancers, called uterine sarcomas, develop from underlying muscle or connective tissue; they are much rarer. This article focuses on the development, diagnosis, and treatment of endometrial cancer.

Causes and symptoms

Although the causes of endometrial cancer vary and in many cases remain unknown, several factors have been identified that increase the risk of developing the disease. Many of these risk factors stem from an imbalance in which levels of the hormone estrogen in the uterus are regularly higher than levels of progesterone. Women who began their menstrual cycles at an early age (before 12 years) or who entered menopause late (after age 52) are at a higher risk for endometrial cancer, probably because of the increased exposure of the uterine wall to estrogen.

Other factors associated with increased exposure to estrogen include lack of a previous pregnancy, obesity, and estrogen replacement therapy following menopause. Women who have taken the breast cancer drug tamoxifen also appear to be at slightly higher risk of developing endometrial cancer, as are females with diabetes. Additional risk factors include race—whites are 70 percent more likely to develop uterine cancer than are blacks—a personal history of breast or ovarian cancer, age (over 40 years), and a family history of endometrial cancer.

The predominant early sign of endometrial cancer is vaginal bleeding or other discharge, especially in postmenopausal women. Any such discharge should be brought to the attention of a physician immediately. Additional possible symptoms are unexplained pelvic pain, a discernible lump or mass, and weight loss.

Diagnosis and prognosis

A biopsy may be used to take samples of uterine tissue, or dilatation and curettage (D & C) may be used to scrape endometrial cells from the wall of the uterus for examination. Cancers of the uterus and surrounding tissues can also be detected by observing the reproductive, digestive, and urinary tracts with specialized viewing scopes. Internal imaging procedures often allow a more precise location and determination of the potential spread of uterine cancer. 

Methods include X rays, computed tomography (CT) scans, magnetic resonance imaging (MRI), and ultrasound. An X-ray procedure called an intravenous pyelogram uses an injected iodine solution to enhance a series of images taken of the urinary tract in cases where spread of cancer to these tissues is suspected.

Once uterine cancer has been diagnosed, its stage is then determined to indicate how far the cancer has progressed. Stage I cancers are localized to the main body of the uterus, whereas stage II tumours have spread to the cervix. Stage III cancers have spread outside the uterus to the vagina, regional lymph nodes, or peritoneum but are still contained within the pelvis. Stage IV cancers have spread to distant organs such as the lungs, bone, bladder, or digestive tract.

Five-year survival for endometrial cancer is quite high when the cancer is diagnosed early, even among patients whose cancer has spread to the cervix. If the cancer has spread beyond the endometrium but remains confined to the pelvis, five-year survival is roughly 50 percent. However, once the cancer has metastasized to other organs, the five-year survival rate is very low.

Treatment

Surgery is used to treat most endometrial cancers. A simple hysterectomy removes the uterus and cervix, whereas a radical hysterectomy also removes underlying connective tissue (the parametrium) and ligaments along with the upper portion of the vagina. Either of these surgeries may be done in conjunction with the removal of the fallopian tubes and ovaries. 

Surgical removal of the uterus or ovaries results in infertility, and removal of the ovaries will also cause women to go immediately into menopause. Lymph nodes may also be removed during surgery. Radiation therapy is sometimes used in conjunction with surgery. External beam radiation resembles traditional X rays in that the radiation is directed from outside the body toward an internal target tissue. In brachytherapy radioactive rods or pellets are implanted to focus the radiation on the cancer and greatly reduce side effects. 

Side effects of pelvic radiation therapy may include diarrhea, fatigue, premature menopause, bladder irritation, or narrowing of the vagina due to scar tissue buildup.

In cases where endometrial cancer has spread beyond the uterus, general or systemic approaches such as chemotherapy may be required so that as many cancerous cells as possible can be sought out and destroyed. Some uterine cancers can be treated in part by using hormonal therapy. If the cancer cells are found to contain a protein called the progesterone receptor, the hormone progesterone may be used to slow the growth of the tumour.

Prevention

Long-term use of oral contraceptives (birth control pills) reduces the risk of endometrial cancer. Regular exams may reveal benign growths in the uterine wall called hyperplasias, which can be removed to eliminate the possibility of their developing into malignant tumours. Some medical societies recommend an annual Pap test plus pelvic exam for all women once they have reached 18 years of age or become sexually active, whichever is earlier.

ALL YOU NEED TO KNOW ABOUT THIS CANCER

 Prostate Cancer

Introduction

Disease characterized by uncontrolled growth of cells within the prostate gland, a walnut-sized organ surrounding the urethra just below the bladder in males. Worldwide among males, the incidence of prostate cancer is surpassed only by lung and stomach cancers; among North American men, only skin cancer occurs more often.

Prostate cancer is rare in men below the age of 50, and in North America the disease is twice as common in black men as it is in whites. Prostate cancer should not be confused with benign prostate hyperplasia, which has similar symptoms and occurs often in older men but is not a type of cancer.

Causes and symptoms

When the prostate gland becomes cancerous, it can put pressure on the urethra, causing frequent or painful urination. Such pressure can also cause difficulty in urinating, a weak and intermittent urine flow, or blood in the urine. The cancerous growth may also put pressure on the nerves required for erection, causing impotence or sexual dysfunction. Other symptoms of prostate cancer include swollen lymph nodes in the groin and pain in the pelvis, hips, back, or ribs.

As in most cancers, the causes of prostate cancer are varied, though most cases are thought to be related to the male hormone androgen. The likelihood of a man's developing prostate cancer doubles if a parent or sibling has had prostate cancer; this suggests that genetic factors play a role. Two genes, known as BRCA1 (breast cancer type 1) and BRCA2 (breast cancer type 2), have been linked to prostate cancer. As their names imply, they are commonly found in mutated forms in some women with breast cancer. However, studies have shown that men carrying mutations in BRCA2 have an increased risk of developing prostate cancer, and mutations in either gene can significantly reduce survival.

Diagnosis

Prostate cancers usually grow very slowly, and individuals may not display symptoms for some time. If the prostate is enlarged, preliminary diagnosis can be made by rectal examination or transrectal ultrasound (TRUS). A blood test for prostate-specific antigen (PSA) is used to detect prostate tumours in their earliest stages. If any of these tests suggest cancer, a biopsy is done to confirm the diagnosis. When caught early, prostate cancer is treatable. A large majority of prostate cancers are diagnosed either before they have spread or when they have spread only locally. Survival rates in these cases are very high.

Treatment

Because prostate cancers usually progress slowly, a physician may recommend a “watchful waiting” approach rather than immediate treatment. This is especially true for patients who are elderly or in otherwise poor health. If treatment is required, the physician may use surgery, radiation, hormone therapy, chemotherapy, or a combination of two or more of these approaches. 

Surgery is usually done only if the cancer has not spread from the prostate. The removal of the entire prostate plus some surrounding tissues (radical prostectomy) may be considered if examination of the pelvic lymph nodes reveals that they are not cancerous. Surgical risks include impotence and urinary incontinence. A second surgical procedure, transurethral resection of the prostate (TURP), is used to relieve symptoms but does not remove all of the cancer. TURP is often used in men who cannot have a radical prostectomy because of advanced age or illness or in men who have a noncancerous enlargement of the prostate.

 In men who are unable to have traditional surgery, cryosurgery may also be used. In this procedure, a metal probe is inserted into the cancerous regions of the prostate; liquid nitrogen is then used to freeze the probe, killing the surrounding cells.

If the cancer has spread from the prostate, radiation therapy may be used. Hormone therapy attacks the male hormones (androgens) that often stimulate the growth of prostate cancer. 

A form of hormone therapy involves drugs called LHRH analogs, or LHRH agonists, that chemically block the production of androgens. Side effects of hormone therapy may include reduced libido, abnormal growth or sensitivity of the breasts, and hot flashes. Orchiectomy, or removal of the testes, cuts off the tumour's supply of testosterone. This surgery can delay or stop tumour growth and eliminates the need for hormone therapy. 

If surgery or hormone therapy fails, chemotherapy may be used. Chemotherapy employs drugs that kill dividing cells (i.e., cancer cells) but is not highly effective in treating prostate cancer. It can, however, slow the growth of the tumour.

Other drugs, called antiandrogens, block the activity of androgens and are often used in combination with other forms of hormone therapy. An antiandrogen called abiraterone inhibits the activity of an enzyme involved in testosterone synthesis in the testes and adrenal glands. 

In clinical trials, abiraterone has shown promise in treating patients with aggressive end-stage prostate cancer, which is usually refractory to hormone therapy and is often fatal. Treatment with abiraterone is associated with reductions in tumour size and PSA levels. Its side effects appear to be limited primarily to hypertension, edema, and potassium deficiency.

Prevention

Risk factors for prostate cancer such as age, race, or family history cannot be avoided. However, studies have suggested that a diet low in fats and high in fruits and vegetables decreases prostate cancer risk. Compounds called lycopenes, which are present in grapefruit, tomatoes, and watermelon, have been linked to reduced risk, as has the nutrient selenium, which is found in nuts, oranges, and wheat germ.

 Physicians disagree on the usefulness of routine screening for prostate cancer. Most medical societies and government agencies feel that screening has not proved to reduce prostate cancer mortality and therefore do not recommend screening. Some medical societies, however, recommend an annual PSA test and digital rectal examination at age 50 for most men and at age 45 for men at higher risk.