Testicles (also called testes or gonads) are male sex glands found behind the penis in a sac of skin called the scrotum. These glands are responsible for producing and storing sperm, as well as producing male hormones.
Testicular cancer begins when cells within the testicle become cancerous and begin to grow out of control. Ninety-five percent of testicular tumors are a type called germ cell tumors.The term "germ cell" refers to cells that make sperm, and is not related to the more common definition of the word "germ," an organism that can cause infections . Other types of tumors found in the testicle are uncommon, and so this article will only address germ cell tumors.
Testicular cancer is classified as one of two types: seminoma, which accounts for 40% of all testicular cancers, and nonseminoma, which includes four sub-types. Seminomas include classic or anaplastic seminoma, which account for 35% of testicular cancers and generally occur between the ages of 25 and 45 years. Spermatocytic seminoma accounts for only 5% of testicular tumors and occurs later in life, with an average age at diagnosis of 65 years.
The nonseminomas include: choriocarcinoma (<1%), embryonal carcinoma (24%), teratoma (30%), and yolk sac tumors (<1%). The peak occurrence for nonseminomas is between ages 20 and 30. Most testicular tumors contain a mixture of both cell types and are called mixed germ-cell tumors. If a tumor contains any proportion of non seminomatous tissue, it is classified as a nonseminoma. If the tumor contains only seminoma cells, it is called a pure seminoma. The two types behave differently and have different prognoses and treatments, so distinguishing between seminoma and nonseminoma is critical to appropriate treatment.
An estimated 8, 48 0 new cases of testicular cancer were diagnosed in 2010 , accounting for only 1% of cancers in men. However, it is the most common form of cancer in men ages 15 to 35 years. In addition, the disease is five times more common in whites than in blacks or Asians.
The cause of testicular cancer is still unknown, but a few things have been linked to a higher risk of developing the disease. An undescended testicle (also called cryptorchidism) is a condition where the testicle did not move into the scrotum before birth. Surgery can be performed to correct the problem and this may lower the risk of developing testicular cancer, particularly when performed before 6 years of age, although this has not been definitely proven. While the risk is higher with this history, it is important to remember that only 1-5% of boys born with an undescended testicle will go on to develop testicular cancer, and 90% of cases are in men without this history.
Men whose testicles did not develop normally are also at higher risk. Klinefelter's Syndrome is a disorder characterized by low levels of male hormones, sterility, breast enlargement, and small testes. This syndrome carries an increased risk of testicular cancer. Men who have already had testicular cancer have a two to five percent chance of developing cancer in the opposite testicle during the 25 years following diagnosis.
Other risk factors include Down's syndrome, certain chemical exposures, and immunosuppression, including HIV/AIDS. Not all risk factors have been clearly identified. Rates have been steadily increasing over the past 40 years, and some experts attribute this to environmental factors and estrogen exposure, either in utero or after birth. Men with a first degree relative (father, brother, son) with the disease are at an increased risk of developing the disease. Researchers have looked for a specific genetic abnormality that could be tested for in families that are affected (like the BRCA 1&2 breast cancer genes), but have not found one.
Unfortunately, the factors listed above that increase risk cannot be prevented. The best outcomes for patients with testicular cancer occur when the disease is found early, so early detection is important. This is best done by testicular self-exam.
There are no routine screening blood tests for germ cell tumors. Most testicular cancers are found by the men themselves, or during a routine exam by a physician. The best method of examination is known as testicular self-exam or TSE. TSE includes regular inspection and palpation of the testicles. Men (and boys) should be familiar with the normal weight, texture and consistency of their testicles. Examination should be done once a month after a warm bath or shower, when the scrotal sac is relaxed. Each testicle should be rolled between the thumb and forefinger to examine for any lumps. Any lumps or abnormalities should be reported to a doctor immediately.
Some men find a lump in their testicle before any other symptoms are present, so a lack of other symptoms does not mean a lump is normal. Some symptoms that may be present are:
These symptoms can be a sign of conditions other than cancer. If any are present, a doctor should evaluate them. Testicular cancer can be quite aggressive and therefore prompt diagnosis of a lump is crucial for the best chance of cure.
If the doctor suspects testicular cancer he may perform several tests to clarify the diagnosis. These tests include an ultrasound of the affected scrotum to identify and better classify a mass in the testicle. Any man with suspected testicular cancer should also have tumor markers for testicular cancer measured. These include: alpha-fetoprotein (AFP), Beta human chorionic gonadotropin (Beta-HCG) and lactate dehydrogenase (LDH). While these levels are not elevated in all types of testicular cancer and alone they cannot diagnose the disease, very high levels are rare without the disease and they can help differentiate between types.
If these tests point to a diagnosis of cancer, the man should be counseled about fertility risks and offered semen cryopreservation as an option for preservation of fertility.
The next step is to remove the affected testicle surgically (called orchiectomy), allowing the pathologist to examine the tumor closely, determining what type of testicular cancer it is. Once the tumor is identified, the next step is to determine how far the cancer has spread - this is known as staging.
Staging may include surgery to remove lymph nodes in the groin and lower abdominal area to test for spread of the cancer and/or CT scans of the chest, abdomen, and pelvis to look for tumor spread, depending on the cell type (seminoma versus nonseminoma). In the American Joint Committee on Cancer staging system, t esticular cancer has three stages:
The treatment of testicular cancer is determined by the type and stage of the tumor. Seminomas and nonseminomas are treated differently from each other, as are stage I, II, and III tumors. For example, nonseminomas tend to be treated more aggressively due to the nature of the tumor.
For many stage I seminomas, surgery alone is curative, and patients may be followed closely with no further therapy. Unfortunately, there is no perfect way to know exactly which Stage I seminoma patients will benefit from further therapy after surgery and which patients will do just fine without it. The goal of any further therapy is to prevent disease recurrence in abdominal lymph nodes (specifically the para-aortic nodes). Different patients have different baseline risks of this disease recurrence after surgery, and so decisions for therapy vs. observation are incredibly complicated. These complex therapy decisions make it important to be treated by a physician who is familiar with this relatively rare disease.
Initially, all patients will require removal of the affected testicle (orchiectomy). The type of surgery performed is known as an inguinal orchiectomy, meaning that the incision is made within the groin, not the scrotum. This surgery may cause concerns related to fertility and sexuality, and these should be discussed with your doctor before the surgery. Many men with testicular cancer have fertility problems before diagnosis which may or may not improve after the surgery, but which should not prevent a man from being offered semen cryopreservation for future fertility options. One testicle produces enough hormones and sperm to have an erection or father a child. Other surgery, chemotherapy, and radiation may affect sperm production and the ability to ejaculate of sperm, so this should be discussed before surgery.
A second surgery, called retroperitoneal lymph node dissection (RPLND), removes the lymph nodes that the tumor typically spreads to. This surgery is often performed in nonseminomas to evaluate tumor spread and lower the risk of relapse, but this benefit is not seen in seminomas, so RPLND is not performed in those tumors.
The standard of care for men with nonseminomas who have residual tumor after completion of chemotherapy is to surgically resect these tumors. This is partly due to the fact that many nonseminomas contain some teratoma tissue that is resistant to chemotherapy, but is removable by a skilled surgeon.
Once again, the choice of whether to treat with adjuvant (meaning after surgery) radiation depends on the tumor type. Seminomas are very sensitive to radiation, and therefore para-aortic and/or pelvic lymph nodes can be treated with radiation to prevent disease recurrence (stage I) or to treat known disease (stage II). Nonseminomas on the other hand are not very sensitive to radiation, and therefore are not typically treated with radiation.
The remaining testicle can be shielded during treatment to reduce the amount of scattered radiation during nodal treatment, thereby reducing the risk of losing sperm-producing ability. Sperm counts may fall after radiation, but typically return to normal within one to two years after treatment.
In some cases, chemotherapy is given to patients after surgery to kill any remaining tumor cells in the body. This is often referred to as adjuvant chemotherapy.
The regimen of chemotherapy that is given varies from doctor to doctor. The regimen is chosen based on the tumor type and stage, the patient's general health, and his ability to tolerate expected side effects. The most commonly used chemotherapy medications include: cisplatin, bleomycin, and etoposide . These treatments are given over a period of several months. As with surgery, sexuality and fertility issues should be discussed before treatment is started.
While the acute effects of cancer therapy are well studied, long- term effects are only recently being identified. Testicular cancer survivors have become a popular group in whom to conduct late effects research, given the treatments they have received and the relatively favorable long-term survival rates for these men. The Institute of Medicine has suggested that all survivors should receive a care plan outlining their late health risks and suggestions for prevention and monitoring. LIVESTRONG Care Plan is a program that develops an individualized survivorship care plan based on the therapies the patient has received. Research is ongoing in the area of late effects and survivors should be alert to the potential of late effects.
Follow-up testing is very important because of the risk of recurrence or the development of a second tumor. Although most recurrences occur within two years for seminomas and five years for nonseminomas, some patients have recurred many years later, so follow-up is very important. This should include: a physical exam by an oncologist, tumor markers (a blood test whose levels are found in higher than normal amounts when a tumor is present), and chest x-ray, with or without a CT scan (depending on the case). For seminomas, t hese tests are performed roughly every two to four months for the first year after therapy, every three to four months for the second year, every four to six months for the third and fourth years , and yearly thereafter.For nonseminomas, these tests may be performed slightly more frequently for the first few years. These are guidelines only, and may vary from case to case and hospital to hospital.
This article is meant to give you a better understanding of testicular cancer. Use this knowledge when meeting with your physician, making treatment decisions, and continuing your search for information. You can learn more about testicular cancer on OncoLink through the related links on the left or through the resources listed below.
The Testicular Cancer Resource Center
The National Cancer Institute
Abeloff, M., Armitage, J., Niederhuber, J., Kastan, M. & McKenna, G. (Eds.): Clinical Oncology (2004). Elsevier, Philadelphia, PA.
The American Cancer Society. Testicular Cancer. http://www.cancer.org/Cancer/TesticularCancer/index
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National Cancer Institute
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