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.
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