- Testicular Cancer Facts
- Testicular Cancer Causes
- Testicular Cancer Symptoms and Signs
- When to Seek Medical Care for Testicular Cancer
- Testicular Cancer Diagnosis
- Medical Treatment
- Surgery and Treatment by Stage
- Testicular Cancer Surgery (Without Medical Treatment)
- Follow-up for Testicular Cancer
- Testicular Cancer Prevention
- Testicular Cancer Prognosis
- Support Groups and Counseling for Testicular Cancer
- For More Information on Testicular Cancer
Testicular Cancer Facts
Testicular cancer is an abnormal growth of cells found in the testicles or testes. The testicles are the male reproductive organs (gonads) where sperm are produced.
- The two small testicular glands lie in a pouch of skin beneath and behind the penis called the scrotal sac, or scrotum.
- They are attached to the ejaculatory duct in the lower pelvis by cords called spermatic cords, which contain the vas deferens, the narrow tube through which the sperm moves out of the testis.
- Beside producing and storing sperm, the testicles (or testes) are the main source of male hormones such as testosterone, which are essential for normal sex drive (libido), for erections, ejaculation, and which drive development of male physical traits such as deep voice and body and facial hair.
- Cancer usually occurs in only one testicle. Less than 5% of the time, it occurs in both testicles. (Usually, if a second testicular cancer arises, the two tumors are found at different times, the second perhaps years later.)
Cancer occurs when normal cells transform and begin to grow and multiply without normal controls.
- This uncontrolled growth results in a mass of abnormal cells called a tumor.
- Some tumors grow quickly, others more slowly.
- Tumors are dangerous because they overwhelm surrounding healthy tissue, taking not only its space but also the oxygen and nutrients it needs to carry out its normal functions.
Not all tumors are cancer. A tumor is considered cancer if it is malignant. This means that, if the tumor is not treated and stopped, it will spread to other parts of the body. Other tumors are termed benign because their cells do not spread to other organs. However, almost all tumors start to cause symptoms when they get large enough.
- Malignant tumors can spread to neighboring structures, usually lymph nodes. They invade these healthy tissues, impairing their function and eventually destroy them.
- Tumor cells sometimes enter the bloodstream and spread to distant organs. There, they can grow as similar but separate tumors. This process is called metastasis.
- The most common places for testicular cancer to spread are the lymph nodes in the area near the kidneys (located in the back of the abdominal area and referred to as the retroperitoneum area), and arecalled the retroperitoneal lymph nodes. It also can spread to the lungs, liver, and rarely to the brain.
- Metastatic cancers arising in the testes are more difficult to cure than benign tumors, but still have very high cure rates.
Testicular cancers can be comprised of one or several different types of tumor cells. The types are based on the cell type from which the tumor arises.
- By far the most common type is germ cell carcinoma. These tumors arise from the sperm forming cells within the testes.
- Other rarer types of testicular tumors include Leydig cell tumors, Sertoli cell tumors, primitive neuroectodermal tumors (PNET), leiomyosarcomas, rhabdomyosarcomas, and mesotheliomas. None of these tumors is very common.
- Most of the information presented here concerns germ cell tumors.
There are two types of germ cells tumors, seminomas and nonseminomas.
- Seminomas arise from only one type of cell: immature germ cells that have not yet differentiated, or turned into the specific types of tissues they will become in the normal testis. These constitute about 40% of all testicular cancers.
- Nonseminomtous germ cell tumors are composed of mature cells that have already specialized. Thus, these tumors often are "mixed," that is, they are made up of more than one tumor type. Typical components include choriocarcinoma, embryonal carcinoma, immature teratoma, and yolk sac tumors. These tumors tend to be faster growing and to spread more aggressively than seminomas.
Testicular cancer is the most common type of cancer in young men 15-35 years of age, but it can occur at any age.
- It is not a common cancer, accounting for only 1%-2% of cancers in men.
- The American Cancer Society estimated that about 8,800 new cases of testicular cancer would be diagnosed in the United States and about 380 men will die of the disease in 2016.
- Testicular cancer is most common in whites and least common in blacks and Asians.
Testicular cancer is one of the most curable of all cancers.
- The cure rate is greater than 90% for most stages. In men whose cancer is diagnosed in an early stage, the cure rate is nearly 100%. Even those with metastatic disease have a cure rate of greater than 80%.
- These figures apply only to men who receive appropriate treatment for their cancer. Prompt diagnosis and treatment are essential.
- Because of its high cure rate, testicular cancer is considered the model of successful treatment for cancer originating in a solid organ. In 1970, 90% of men with metastatic testicular cancer died of the disease. By 1990, that figure had almost reversed - nearly 90% of men with metastatic testicular cancer were cured.
Testicular Cancer Causes
It is not known exactly what causes testicular cancers. Certain factors, listed here, appear to increase a man's risk of developing a testicular cancer. Many others have been proposed, but are either unproven or discredited.
Cryptorchidism: The testicles form in the abdomen of the developing fetus. While the fetus is still in the womb, the testicles begin their gradual descent to the scrotum. Oftentimes, this descent is not complete at birth but occurs during the first year of life. Failure of the testicle to appropriately descend into the scrotum is called undescended testicle, or cryptorchidism.
- It can occur on one or both sides.
- If the testicles do not fully descend, the infant usually undergoes surgery to bring the testicle(s) into the scrotum.
- The risk for testicular cancer is three to five times higher in males born with cryptorchidism, even after surgery to bring the testicle(s) into the scrotum.
- Because of this increased risk, men with this type of condition should be even more rigorous about performing regular testicular self-exams.
Testicular Cancer Symptoms and Signs
Family History of testicular cancer
HIV infection: There appears to be a higher risk of testicular cancer in men with HIV infection.
Age: Men between 20 and 35 are most commonly affected. Six percent occur in children. Seven percent occur in men over 55.
History of Testicular Cancer in the Other Testicle
Most testicular cancers are discovered by the man himself when he notices a painless swelling, lump, or pain in a testicle.
- The lump may be small (the size of a pea) or large (the size of marble or even larger).
- Less common symptoms include a lasting ache or sensation of heaviness in the testicle.
- Significant shrinking of a testicle or a hardness of the testicle are other less common symptoms.
- Occasionally, a dull ache or fullness in the abdomen, pelvis, or groin is the only symptom.
- Rarely, the first symptom may be breast tenderness (3%), a result of hormonal changes brought on by the cancer.
Changes in the testicle can be detected early by practicing monthly testicular self-examination. Self-exam is easy to do. Testicular self-examination is key to recognizing testicular cancer early. Males older than 18 years of age should be encouraged to perform monthly inspections of each testicle. Notify your health-care provider about any suspicious finding or concern.
When to Seek Medical Care for Testicular Cancer
The symptoms of testicular cancer can also have many other causes that have nothing to do with cancer. If men have any of these symptoms, it is best to be examined in a timely manner to rule out cancer and receive treatment for whatever condition they may have.
If men notice any of these symptoms or any abnormality or change in their testicles, they should visit a medical professional immediately, preferably a physician who specializes in diseases of the genitals and urinary tract (urologist).
- Fear, ignorance, and denial are common reasons that men delay seeking medical help. In fact, many men will wait many weeks, months, or sometimes even more than a year, before consulting a doctor. This increases the risk that testicular cancer will be diagnosed at a more advanced stage and may require more intensive treatment. While highly curable, not all testicular cancer patients will be cured of their disease and can die of it. Early detection and treatment remain very important.
- It is important to check out any lump or enlargement right away, because cancer of the testicle can grow rapidly and may double in size in as little as every 10-30 days.
Any severe testicular pain or injury warrants a visit to a hospital emergency department. A change in the appearance or an examination of the testicle should prompt a visit to your health-care provider.
If a male does not have a regular health-care provider, he should ask family members and friends for a referral. If that doesn't work, services listed below are available to help him find a urologist.
- Many local and state medical societies can provide a list of urologists, as can some hospitals.
- The web site of the American Urological Association can help anyone find a urologist located close to anyone's local area. Go to the web site http://www.urologyhealth.org/find_urologist/html/index.asp and enter the closest zip code to the person's residence, and a listing of local urologists and their contact information will be available.
Testicular Cancer Diagnosis
Many medical conditions can cause the symptoms or physical findings of testicular cancer. On hearing the symptoms, or finding a lump, swelling, or other change on physical examination, the health-care provider will develop a list of possible causes. He or she will then do a systematic evaluation to try to pinpoint the diagnosis. The provider often starts by asking questions about the person's symptoms, medical and surgical history, lifestyle and habits, and any drugs or medications the person takes.
The next step, in most instances, should be an ultrasound of the scrotum.
- Ultrasound is a noninvasive method of evaluating the scrotum and testicle.
- Sound waves are emitted via a probe that is moved over the scrotum. These are transmitted as visual images to a video monitor.
- The images show the contour of the testicle, potential fluid within the scrotum, and blood flow. In most cases, abnormalities of the testicle show up very well.
Patients will probably have blood drawn for lab tests listed below.
- The most important is for tumor markers, which are substances released into the blood by the tumor tissue.
- These substances are alpha-fetoprotein (AFP), beta human chorionic gonadotropin (bHCG), and lactate dehydrogenase (LDH).
- High levels of these substances may indicate the presence of testis cancer present in the body.
- Tumor markers may assist in predicting the type of cancer, its extent, and how it might respond to treatment.
- An effective treatment causes the tumor markers to return to a normal level. If the tumor markers do not return to normal after treatment, this usually means that the surgery did not "get it all," and cancer has spread to another part of the body.
- If the tests for tumor markers show elevations in those tests before treatment has begun, then tumor markers will be checked regularly throughout and after treatment to detect response to treatment and remaining disease.
Some individuals may have their urine tested for signs of damage to the organs of the urinary tract, which are closely related to the reproductive organs.
Tumor stage is a critical measure of how much the cancer has spread. Knowing the stage is important because it guides treatment. Preliminary staging is based on the results of the imaging studies and lab tests. Testicular cancer typically spreads in a step-by-step fashion. If it spreads from the testicle, the first place it typically goes is in the area near the kidneys, called the retroperitoneum. It then can spread to the lungs, brain, or liver.
- Stage I: Tumor is limited to testicle without any evidence of disease in the abdomen, chest, or brain.
- Stage IIA: Tumor is in the testicle and has spread to a small number of retroperitoneal lymph nodes measuring less than 2 cm in greatest diameter.
- Stage IIB: Tumor is in the testicle and has spread to a retroperitoneal lymph node(s) measuring between 2 cm and 5 cm in greatest diameter.
- Stage IIC: Tumor is in the testicle and has spread to the retroperitoneal lymph nodes measuring greater than 5 cm in greatest diameter.
- Stage III: Tumor has spread beyond the retroperitoneal lymph nodes, typically to the lungs, liver, or brain.
Many experts also break testicular tumors down into "good-risk" and "poor-risk" groups.
- Poor-risk tumors are linked with very high levels of tumor markers or spread beyond the retroperitoneal lymph nodes and lungs.
- The cure and survival rates are significantly lower for poor-risk tumors than they are for good-risk tumors.
Staging can only be estimated from imaging studies and tumor markers. The only way to confirm the diagnosis of testicular cancer is through surgical removal of suspected tumor tissue that is biopsied. It is not recommended that a needle be put through the scrotum into the testicle. That can cause abnormal patterns of spread of a testicular cancer. It is best to remove the testicle in question. The other testicle will continue to work and the patient will still make enough sperm and male hormone to function normally.; often it means that a testicle is removed. Some men with testicular cancer have low sperm counts already and this can be tested for, or may already be recognized in the patient from earlier evaluations..
- The testicle is removed in a procedure called radical orchiectomy, which requires an incision in the groin (inguinal region) and complete removal of the testicle and spermatic cord.
- A small piece of the tumor (biopsy) is examined by a physician who specializes in diagnosing disease by examining cells and tissues (pathologist).
The initial treatment for testicular cancer is orchiectomy (surgical removal of the testicle and the attached cord). This is the standard therapy and is recommended for all men with testicular cancer.
Whether a patient has additional therapy following surgery depends on a number of factors: the tumor type, the location and extent of the cancer (whether it is limited to the scrotum or has spread to the abdominal cavity or other sites), and the serum tumor marker levels (AFP and beta-HCG). Men should discuss their urologist's recommendations and the risks and benefits of each therapy before making a decision. Some individuals may want to consider getting a second opinion before beginning treatment.
For germ cell tumors, the following options are available for treatment after orchiectomy.
Surveillance: This is sometimes called "watchful waiting" or "observation." What it means is that the patient receives no further treatment after orchiectomy but must adhere to a very strict schedule of follow-up visits with a urologist. The idea is to detect any potential residual or recurrent cancer and then proceed with treatment at that point.
- Surveillance protocols may vary by physician, but a typical protocol would require visits every two months for the first year, with tumor markers, chest X-ray, and CT scan of the abdomen done at every visit or every other visit.
- Follow-up is lifelong, gradually (over five or more years) tapering the frequency of the visits and tests to once per year (as long as no cancer is detected).
- Surveillance is a calculated gamble. The patient is betting that they have no residual disease but that, if they do, it will be found early while still highly curable. The advantage to this choice is that patients are avoiding the potential side effects of and lengthy recovery from chemotherapy or radiation therapy.
- If a patient is concerned about being able to stick with the rigorous surveillance schedule, immediate surgery, radiation, or chemotherapy may be the best choice.
- Surveillance is not recommended for all men with testicular cancer. Generally, it is reserved for men with stage I disease at low-risk of recurrence.
- Statistically, men who choose surveillance for select stage I cancer have just as good a chance of ultimate cure as men who proceed with immediate treatment.
- The risks and benefits are complex. These should be discussed in great detail with the physician before making a decision.
Chemotherapy: Combinations of chemotherapy drugs are the standard, whether a cancer is good risk or poor risk. The revolution in treatment of testicular cancer is attributed to the use of these drug regimens. The drugs are given in cycles consisting of about five days of intense treatment followed by a recovery period of approximately three weeks.
- Chemotherapy is the standard treatment for stage III disease.
- Patients will be referred to a cancer specialist (oncologist) for chemotherapy.
- Good-risk tumors (as determined by blood tumor marker levels and the radiographic extent of disease) are treated with a combination called BEP (bleomycin [Blenoxane], etoposide [VePesid], and cisplatin [Platinol]) for three cycles or a combination of etoposide and cisplatin for four cycles.
- Poor-risk tumors are also treated with BEP but for four cycles. Another option is VIP (etoposide [VP-16], ifosfamide [Ifex], and cisplatin).
- Each cycle lasts three to four weeks, although the next cycle may be postponed if the person has severe side effects.
- In cases of testicular cancer when the initial chemotherapy either fails to get rid of all evidence of the cancer recurs after the first line of chemotherapy, high-dose chemotherapy with stem cell transplant is used.
- Side effects of the standard chemotherapy regimens may include reduction in kidney function, alterations in skin sensation (17%-45% of men), hearing changes (30%-40%), decreased blood circulation to extremities (25%-50%), cardiovascular disease (18%), testosterone deficiency (15%), lung damage, infertility (30%), and a slight increase in the incidence of secondary solid tumors.
Radiation therapy: Radiation is the targeting of high-energy radiation beams directly at the tumor. In testicular cancer, the beam is targeted mainly at the lower abdomen to destroy any residual disease in lymph nodes.
- Radiation is usually offered for stage I or low-volume stage II seminoma. It is not recommended for nonseminomatous germ cell tumors.
- Patients will be referred to a specialist in radiation therapy (radiation oncologist) for this treatment.
- The radiation is given in a series of brief treatments five days a week, usually for three to four weeks. The repeated treatments help destroy the tumor.
- The remaining testicle is shielded to prevent damage to healthy tissue.
- Side effects include nausea, vomiting, diarrhea, loss of energy, irritation or mild burning of the skin exposed to the radiation beam, impaired fertility, and slightly increased risk of other cancers.
Surgery and Treatment by Stage
Surgery: A second more complex surgery is offered to some men. This surgery is designed to remove any residual cancer in the retroperitoneal lymph nodes and is called a retroperitoneal lymph node dissection, or RPLND.
- This surgery is not offered to all men with testicular cancer. It is usually offered to men with stage I or II nonseminomatous germ cell tumors who are thought to have a high risk of cancer in the retroperitoneum. It is also commonly recommended following chemotherapy if abnormally enlarged lymph nodes are present in the retroperitoneum. It is almost never offered to men with seminoma.
- The decision to go ahead with RPLND is based on tumor marker levels and findings of CT scan of the abdomen after orchiectomy. Rising or persistently high tumor marker levels or enlarged lymph nodes on the CT scan after orchiectomy strongly suggest residual cancer. Most experts recommend chemotherapy in these cases, not RPLND.
- In some cases, both RPLND and chemotherapy are recommended.
Summary of treatment by stage
- Seminoma: Orchiectomy with or without radiation to the retroperitoneum
- There is a 15% chance that tumor will spread to the retroperitoneum.
- Because radiation can eliminate this cancer 99% of the time and is generally very well tolerated, radiation therapy is typically recommended.
- Single dosage of chemotherapy (carboplatin [Paraplatin]) may be an effective alternative treatment but is not commonly recommended in the United States.
- For those who choose surveillance, frequent visits (every one to two months) and tests are essential.
- Nonseminomatous germ cell tumors: Orchiectomy followed by RPLND or chemotherapy
- Of men who have no evidence of cancer spread on CT scan, 30%-50% do have microscopic spread. This risk can be predicted by a pathologic evaluation of the testicular tumor and depends on the presence of embryonal carcinoma or invasion of the cancer into the lymphatic/blood vessels. Elevated tumor markers which do not return to normal after the orchiectomy indicate this as well.
- Treatment options include surgery to remove the lymph nodes in the retroperitoneum (RPLND), chemotherapy, or surveillance.
- Seminoma: Orchiectomy followed by radiation therapy, although chemotherapy is also effective
- Nonseminomatous germ cell tumor: Chemotherapy or RPLND
- Seminoma: Either radiation or chemotherapy
- Nonseminoma: Either chemotherapy or RPLND
Stage IIC, III
- Seminoma: Chemotherapy followed by post-chemotherapy RPLND, if needed
- Nonseminoma: Chemotherapy followed by post-chemotherapy RPLND, if needed
Most non-germ cell testicular tumors usually require no further treatment after orchiectomy. If there is a high-risk of metastases or if metastases are present, further surgery is often recommended.
Testicular Cancer Surgery (Without Medical Treatment)
Orchiectomy: This operation removes the entire testicle and the attached cord.
- A small incision is made where the leg meets the abdomen (the inguinal region) on the side of the testicle with the tumor.
- The testicle and attached cord are gently moved up out of the scrotum and out of the incision. Only a few stitches are needed.
- Typically, the surgery takes 20-40 minutes. It can be done with a general, spinal, or local anesthetic.
- Absorbable stitches are usually used, and the patient can go home the same day as surgery.
- Many urologists recommend that men bank their semen prior to the surgery, because it can take months to years after therapy to return to full fertility.
- This surgery is recommended for all men with testicular cancer. It is the first and, for some men, the only treatment needed.
- This surgery should not interfere with normal erection, ejaculation, orgasm, or fertility.
Retroperitoneal lymph node dissection: This operation removes the retroperitoneal lymph nodes when they are thought to harbor cancer.
- This is a complex and lengthy surgery that requires a single large incision or several small incisions in the abdomen.
- Most of the abdominal organs have to be moved to get at the retroperitoneal area.
- The operation itself takes several hours and requires general anesthesia.
- Patients will stay in the hospital for about three to five days.
- Besides the usual complications of surgery and general anesthesia, this operation involves the possibility of nerve damage causing retrograde ejaculation. This means that instead of ejaculating in the usual manner, the semen moves backward and ends up in the bladder. This occurs in fewer than 5% of men who have this operation. If there is a large lymph node in the retroperitoneum, rates of retrograde ejaculation increase.
- Another possible complication is intestinal blockage caused by scarring in the abdomen.
Follow-up for Testicular Cancer
Follow-up is the care patients receive after their cancer is diagnosed and treated.
- Follow-up in testicular cancer varies and is based on the type of cancer, the cancer's response to treatment, and the physician's preference.
- The idea is to monitor the patient's recovery and look for early signs of cancer recurrence.
- Follow-up involves regular visits to the urologist for physical examination and tests.
- The urologist will probably want to see the patient every few months for the first two years, then every six to 12 months for five years or longer.
- Patients treated for testicular cancer can expect periodic CT scans, chest X-rays, and blood tests for life.
Cancers can recur after treatment, and accurately predicting which men will have a recurrence is impossible. Recurrences, if detected and treated early, have a high rate of cure. The patient's best way to ensure that a recurrence is caught early is to carefully follow the physician's follow-up recommendations.
Testicular Cancer Prevention
There is no known way to prevent testicular cancer.
All men (an in particular, those 18-44 years of age) should perform monthly testicular self-examinations. The point of these examinations is not to find a cancer but to get familiar with how your testicles feel so that you will notice if something changes.
- The best time to do the exam is after a warm bath or shower, when the muscles are most relaxed.
- Stand in front of a mirror that allows full view of the scrotum.
- Examine each testicle, one at a time.
- Use two hands: Hold the testicle between the thumbs and first two fingers of both hands, with the thumbs in front and the fingers behind. Gently roll the testicle around between these fingers, carefully feeling the testicle and the cord, trying not to miss a spot.
- Locate the epididymis, the soft tube at the back of each testicle that carries the sperm. Learn to recognize it.
- Men should not feel any pain during the exam.
- If a person finds anything that alarms or concerns them, have it checked out by a primary-care provider or a urologist.
- If anyone has trouble with the exam, ask a health-care provider how to do the correct method of self-exam of the testicles.
Testicular Cancer Prognosis
After treatment for testicular cancer, most men enjoy a full, cancer-free life. The patient's ability to have an erection and orgasm will likely not change after testicular cancer treatment. However, men who wish to father children in the future are strongly urged to take advantage of sperm banking in case their fertility is impaired by the cancer or treatment. Orchiectomy alone does not affect fertility, but chemotherapy, radiation therapy, and RPLND all may affect fertility in different ways. At 10 years, testicular cancer survivors are one-third less likely to father children as their peers.
Survival rates depend on the stage and type of testicular cancer.
- Stage I seminoma has a 99% cure rate.
- Stage I nonseminoma has about a 97%-99% cure rate.
- Stage IIA seminoma has a 95% cure rate.
- Stage IIB seminoma has an 80% cure rate.
- Stage IIA nonseminoma has a 98% cure rate.
- Stage IIB nonseminoma has a 95% cure rate.
- Stage III seminoma has about an 80% cure rate.
- Stage III nonseminoma has about an 80% cure rate.
Support Groups and Counseling for Testicular Cancer
Living with cancer presents many new challenges for the patient and for their family and friends.
- Patients will probably have many worries about how the cancer will affect them and their ability to "live a normal life": to carry on their relationships, to continue in school or hold a job, and to participate in activities they enjoy.
- Many people feel anxious and depressed. Some people feel angry and resentful, while others feel helpless and defeated.
For most people with cancer, talking about their feelings and concerns helps.
- Friends and family members can be very supportive. They may be hesitant to offer support until they see how the person are coping. Patients should not wait for them to start any discussion about testicular cancer. If patients want to talk about their concerns, most individuals are urged to start the discussions with their family and friends.
- Some people don't want to "burden" their loved ones, or they prefer talking about their concerns with a more neutral professional. A social worker, counselor, or member of the clergy can be helpful to patients if they want to discuss their feelings and concerns about having cancer. Often, the urologist or oncologist is able to recommend or may recommend the patient to a cancer support group.
- Many people with cancer are helped profoundly by talking to other people who have cancer. Sharing concerns with others who have been through the same thing can be remarkably reassuring. Support groups of people with cancer may be available through the medical center where the patient is receiving their treatment. The American Cancer Society also has information about support groups all over the United States.
For More Information on Testicular Cancer
National Cancer Institute, Cancer Information Service (CIS)
Toll-free: 800-4-CANCER (800-422-6237)
TTY (for deaf and hard-of-hearing callers): 800-332-8615
For information about clinical trials in cancer treatment, visit the National Institute of Health's Clinical Trials database.
Medically reviewed by Jay B. Zatzkin, MD; American Board of Internal Medicine with subspecialty in Medical Oncology
Krege, S., J. Beyer, R. Souchon, et al. "European Consensus Conference on Diagnosis and Treatment of Germ Cell Cancer: A Report of the Second Meeting of the European Germ Cell Cancer Consensus Group (EGCCCG): Part I." Euro Uro 53.3 Mar. 2008: 478-496.
Krege, S., J. Beyer, R. Souchon, et al. "European Consensus Conference on Diagnosis and Treatment of Germ Cell Cancer: A Report of the Second Meeting of the European Germ Cell Cancer Consensus Group (EGCCCG): Part II." Euro Uro 53.3 Mar. 2008: 497-513.
Travis, L., C. Beard, J. Allan, et al. "Testicular Cancer Survivorship: Research Strategies and Recommendations." JNCI 102.15 Aug. 2010: 1114-1130.