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Testicular Cancer
Overview
Testicular cancer develops in the testicles (testes), the male reproductive glands. The testicles are located in the membranous pouch below the penis (scrotum) and are suspended from the body by the spermatic cord. They produce male reproductive cells (sperm) and testosterone. Testicular cancer is treated successfully in more than 95% of cases.
Anatomy
The testicles are primarily made up of a mass of seminiferous tubules in which sperm develop. The tubules are lined with Sertoli cells, which protect and supply nutrients to developing sperm. Sertoli cells also secrete the hormone inhibin, which is involved in the regulation of sperm production.
Leydig cells, located in tissue between the seminiferous tubules, secrete testosterone and androsterone. These hormones stimulate the development of male sex organs, beard growth, muscle mass, and deepening of the voice.
Types
Most (95%) testicular cancer originates in undeveloped cells (germ cells) that produce sperm. These tumors, called germ cell tumors (GCTs), are most common in men between the ages of 20 and 40 and are curable in more than 95% of cases. There are two main types: seminomas and nonseminomas. A third type, called stromal tumors, develops in the supporting tissues of the testicle.
Approximately 40% of GCTs are seminomas, which are classified as either typical or spermatocytic. Typical seminomas account for 90% of this type. They often cause unilateral (i.e., on one side) testicle enlargement or more often a painless lump in the testicle. Spermatocytic seminomas grow slowly, usually do not spread to other parts of the body (metastasize), and are most common around age 65.
Nonseminomas account for 60% of GCTs and develop in younger men (usually between 15 and 35). Most nonseminomas contain cells from at least two subtypes, including the following:
• Choriocarcinoma (rare; aggressive; likely to metastasize)
• Embryonal carcinoma (accounts for 20% of cases; likely to metastasize)
• Teratoma (usually benign in children; rarely metastasize)
• Yolk sac carcinoma (most common in young boys; rare in men)
Testicular cancer may also develop in the supportive, hormone-producing tissue of the testicles (stroma). This type accounts for 4% of testicular cancer in men and 20% in boys. Types of stromal tumors include Leydig cell tumors and Sertoli cell tumors. Seventy-five percent of Leydig cell tumors develop in men and 25% develop in boys. Most tumors of this type are benign and are treated successfully with surgery. If the tumor metastasizes, it often does not respond well to radiation or chemotherapy and the prognosis is poor.
Sertoli cell tumors develop in Sertoli cells that nourish the sperm-producing germ cells. These tumors are usually benign; metastatic tumors of this type are rare, yet resistant to treatment.
Secondary tumors in the testicles usually migrate from the lymph or lymph nodes. Testicular lymphoma is more common than primary testicular cancer in men over 50. Other cancers (e.g., prostate, lung, skin) may also spread to the testicles.
Incidence and Prevalence
Incidence of testicular cancer is rising. According to the American Cancer Society, approximately 7600 cases are diagnosed and about 400 men die of the disease each year in the United States. The disease is most prevalent in men between the ages of 18 and 32 and is approximately 5 times more common in Caucasians than African Americans. Germany, Scandinavia, and New Zealand have the highest incidence of testicular cancer and Asia and Africa have the lowest.
Risk Factors
The major risk factors for testicular cancer are cryptorchidism (i.e., a condition in which the testes do not descend into the scrotum; also called undescended testicle) and Klinefelter’s syndrome (i.e., a congenital disorder caused by an extra X chromosome that results in failure of the testicles and usually is diagnosed after puberty). Other risk factors include a family or personal history of testicular cancer and genetic abnormality of chromosome 12.
Causes
The cause of testicular cancer is unknown. One theory suggests that testicular germ cell tumors form when germ cells develop into sperm cells with 46 chromosomes. Normally, germ cells with 46 chromosomes develop into sperm cells with 23 chromosomes (during a process called meiosis).
Signs and Symptoms
Testicular cancer does not always produce symptoms. A mass or lump in the testicle is usually the first sign of the disease. The mass may or may not be painful. Other symptoms include testicular swelling, hardness, and a feeling of heaviness or aching in the scrotum or lower abdomen.
Some types of testicular cancer (e.g., choriocarcinoma, Leydig cell tumors, Sertoli cell tumors) produce high levels of hormones (e.g., human chorionic gonadotropin [HCG], estrogen, testosterone). Increased levels of HCG may cause breast tenderness and abnormal growth of breast tissue (gynecomastia). Increased levels of estrogen may cause a loss of sexual desire (libido) and increased levels of testosterone may cause premature growth of facial and body hair in boys.
Testicular cancer that has spread to other organs (metastasized) may cause low back pain, shortness of breath, chest pain, and cough.
Diagnosis
Diagnosis of testicular cancer involves a patient history, physical examination, and diagnostic tests. A patient history is taken to evaluate risk factors. During physical examination the physician feels (palpates) the testicles and the abdomen to detect a lump, swelling, or enlarged lymph nodes. Diagnostic tests include ultrasound, CT scan, and blood tests.
Testicular Self-Examination
Physicians routinely examine the testicles during a physical. But monthly testicular self-examinations (TSE) are recommended after puberty, especially for men at increased risk for testicular cancer. Finding testicular tumors early increases the chance for curing the disease.
The best time to perform the exam is during or after a warm bath or shower, when the skin of the scrotum is relaxed. Examine each testicle gently with both hands. The index and middle fingers should be placed underneath the testicle, and the thumbs placed on the top. Roll the testicle gently between the thumbs and fingers.
One testicle may feel larger than the other. This is normal. You will also feel a cord-like structure on the top and back of the testicle that stores and transports the sperm. This is the epididymis and should not be confused with an abnormal lump.
If you find an abnormal lump on the front or the side of the testicle, make an appointment to see your physician immediately. If the lump is caused by an infection, the physician can prescribe treatment. If the lump is not an infection, the physician will perform tests to determine if it is a tumor.
Differential Diagnosis
To diagnose testicular cancer physicians must rule out the following conditions:
• Accumulation of fluid in the testicle (hydrocele)
• Cancer of the lymphatic system (lymphoma)
• Cyst on the surface of the testicle that contains sperm (spermatocele)
• Enlarged veins in the testicle (varicocele)
• Inflammation of the surface of the testicle (epididymitis)
• Twisting of the testicle (testicular torsion)
Ultrasound uses sound waves to produce an image of the testicle on a computer screen. This test determines if a mass is a benign condition (e.g., hydrocele) or a solid tumor. A solid tumor in the testicle is usually cancerous.
When a solid tumor is detected by ultrasound, computed tomography (CT scan) of the pelvis, abdomen, and chest is performed to determine if the cancer has spread to lymph nodes or other organs. CT scan uses x-rays and, in some cases, a contrast agent (dye) to produce a detailed image on a computer screen.
Blood Tests
Certain types of testicular cancer raise the level of substances (so-called tumor markers) in the blood. For example, nonseminomas raise the level of proteins (e.g., alpha-feta protein [AFP]); seminomas and nonseminomas raise the level of hormones (e.g., human chorionic gonadotropin [HCG]); and advanced seminomas and nonseminomas usually raise the level of enzymes (e.g., lactate dehydrogenase [LDH]). Blood tests that measure the levels of these substances are used to diagnose testicular cancer and, in some cases, to determine the extent of the disease.
Biopsy is performed when other diagnostic tests are inconclusive. In this procedure, the surgeon makes an incision in the groin (inguinal incision), removes the testicle from the scrotum without cutting the spermatic cord, and may remove suspicious tissue for microscopic examination. More often the testicle is removed when the mass is shown to be within the testicle due to the very high incidence of malignancy. If no cancer is found, the testicle is returned to the scrotum. If cancer is detected, the testicle and spermatic cord are removed (called orchiectomy) and the stage of the disease is determined.
Treatment
Treatment for testicular cancer depends on the stage of the disease. Surgery to remove the testicle is sometimes combined with radiation and/or chemotherapy. Some patients choose to store frozen sperm in a sperm bank before treatment to ensure fertility.
Surgery
Radical inguinal orchiectomy is the surgical removal of the testicle and the spermatic cord through an incision in the groin. Surgery is performed under general or regional anesthesia and takes approximately 1 hour. Most patients remain in the hospital overnight.
If CT scan indicates that testicular cancer has metastasized to the lymph nodes, retroperitoneal lymph node dissection is often performed. All of the lymph nodes connected to the affected testicle are removed in this procedure. Such dissection is usually done at a later date.
Retroperitoneal lymph node dissection is performed under general anesthesia, requires a large incision, and usually takes 4 to 6 hours.
Complications associated with surgery include the following:
• Adverse reaction to anesthesia
• Bowel obstruction and inactivity
• Damage to surrounding organs, blood vessels, and nerves
• Infection
• Infertility (caused by nerve damage that results in retrograde ejaculation)
• Lymph-filled cyst (lymphocele)
Following surgery, patients are usually encouraged to get up as soon as possible. Pain at the incision site and numbness in the area surrounding the incision are common, and pain relievers are often prescribed. Driving and heavy lifting should be avoided for a several weeks.
Men who have had an orchiectomy may choose to have a testicular prosthesis surgically implanted into the scrotum. The prosthesis is filled with saline and is made to look and feel natural.
Radiation
Radiation uses high energy x-rays to destroy cancer cells. In testicular seminoma, external beam radiation (from a machine outside of the body) is primarily used after orchiectomy (called adjuvant therapy) to destroy cancer cells that have spread (metastasized) to lymph nodes. Testicular seminoma typically requires a lower dose of radiation than other types of cancer. During treatment, a shield is placed over the remaining testicle to preserve fertility.
Side effects of radiation include the following:
• Diarrhea
• Fatigue
• Nausea
• Skin irritation that resembles sunburn
Chemotherapy
Chemotherapy is a systemic (i.e., circulates throughout the body via the bloodstream) cancer treatment that uses toxic drugs to destroy cancer cells. In testicular cancer cases, it is used to destroy cancer cells that remain after surgery. Chemotherapy may be administered intravenously (IV), taken in pill form, or injected into muscle.
Drugs used alone or in combination to treat testicular cancer include the following:
• Cisplatin (Platinol®)
• Vinblastine (Velban®)
• Bleomycin (Blenoxane®)
• Cyclophosphamide (Cytoxan®)
• Etoposide (Etopophos®)
• Ifosfamide (Ifex®)
Side effects of chemotherapy are often severe and include gastrointestinal disturbances, low blood count, skin disorders, and neurological disorders.
Prognosis
Prognosis for testicular cancer depends on the stage of the disease at diagnosis. More than 95% of cases are treated successfully.
Prevention
Testicular cancer cannot be prevented.
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