Cancer starts when cells begin to grow out of control. Cells in nearly any part of the body can become cancer and spread to other parts of the body. To learn more about how cancers start and spread, see What Is Cancer?

Cancer that starts in the testicles is called testicular cancer. To understand this cancer, it helps to know about the normal structure and function of the testicles.

What are testicles?

Testicles (also called testes; a single testicle is called a testis) are part of the male reproductive system. The 2 organs are each normally a little smaller than a golf ball in adult males. They're held within a sac of skin called the scrotum. The scrotum hangs under the base of the penis.

Doctors often use survival rates as a standard way of discussing a person’s prognosis (outlook). Some patients with testicular cancer may want to know the survival statistics for people in similar situations, while others may not find the numbers helpful, or may even not want to know them.

The 5-year survival rate refers to the percentage of patients who live at least 5 years after their cancer is diagnosed. Of course, many people live much longer than 5 years (and many are cured).

Five-year relative survival rates assume that some people will die of other causes and compare the observed survival with that expected for people without the cancer. This is a better way to see the impact of the cancer on survival.

In order to get 5-year survival rates, doctors have to look at people who were treated at least 5 years ago. Improvements in treatment since then may result in a more favorable outlook for people diagnosed with testicular cancer today.

Survival rates are often based on previous outcomes of large numbers of people who had the disease, but they cannot predict what will happen for any one person. Many other factors may affect a person’s outlook, such as your age and how well the cancer responds to treatment. Your doctor can tell you how the numbers below may apply to you.

Survival rates, by stage

The survival statistics below come from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) database. They're based on patients who were diagnosed with testicular cancer (of any type) between 2003 and 2009.

The SEER database does not divide survival rates by AJCC TNM stage. Instead, it divides cancers into summary stages: localized, regional, and distant:

• Localized means that the cancer is still only in the testicle. This includes most AJCC stage I tumors (stage 0 cancers are not included in these statistics).
• Regional means that the cancer has spread to nearby lymph nodes or tissues. This includes T4 tumors and cancers with lymph node spread (all stage II cancers and some stage IIIB and IIIC cancers).
• Distant means that the cancer has spread to organs or lymph nodes away from the tumor, such as all M1 cancers (which can be stage IIIA, IIIB, or IIIC).

Other prognostic factors

As can be seen in the table above, how far the cancer has spread at the time it’s diagnosed affects your chances of long-term survival. But overall, the outlook for those with testicular cancers is very good, and most of these cancers can be cured, even if they have spread.

Some other factors can also affect outlook, such as:

• The type of testicular cancer
• Levels of tumor markers after the testicular tumor has been removed

Ask your doctor how these or other prognostic factors might affect your outlook.

Important research into testicular cancer is being done in many university hospitals, medical centers, and other institutions around the world. Each year, scientists find out more about what causes the disease, how to prevent it, and how to improve treatment.

Genetics

In recent years, researchers have found that changes in certain genes, such as PLAP, NANOG, SOX2, and REX1, appear to be linked to testicular cancer. These findings could someday help identify men at higher risk, but they need to be studied more.

Scientists are also studying changes in the genes of testicular cancer cells to learn more about the causes of this disease. Their hope is that improved understanding will lead to better treatment. Certain gene mutations found in the testicular cancer cells have been linked to resistance to chemotherapy and predict poor outcomes. These findings may help personalize treatment. They could also help find new drugs to treat testicular cancer, drugs that can target these gene mutations. A better understanding of the genetic changes will also help doctors decide which patients need further treatment and which ones can be safely treated with surgery alone.

Treatment

Clinical trials have refined doctors’ approaches to treating these cancers. For example, studies have found factors that help predict which patients have a particularly good prognosis and may not need lymph node surgery or radiation therapy. Studies also have found unfavorable prognostic factors that suggest certain patients may benefit from more intense treatment.

New drugs and new drug combinations are being tested for patients with testicular cancer that comes back or doesn't respond to treatment. And high-dose chemotherapy followed by a stem cell transplant is being studied for men who have tumors with a poor prognosis.

Sentinel lymph node biopsy is used for other types of cancer to help limit the number of nodes that are removed, which can decrease the risk of long-term side effects. Researchers are looking at how this procedure might be used with testicular cancer.

Other studies are using robotic-assisted surgery to remove lymph nodes after chemotherapy. It appears to be a safe option instead of standard "open" surgery, but more research is needed to show this and to see if there are other benefits.

Long-term treatment side effects

A large amount of work is being done to try to better understand, limit, and prevent the long-term toxicities of treatment while maintaining the high cure rate. Chemo combinations are being refined to see if eliminating certain drugs, replacing them with others, or lowering doses can reduce side effects for some men without reducing the effectiveness of treatment.

Doctors also want to be able to predict whose cancer is more likely to come back later (recur) and then base treatment on this. This way they couldn't under- or over-treat anyone. For instance, one study reported good results by individualizing treatment in men with metastatic cancer based on the decline of tumor marker (AFP and HCG) levels after chemo, giving more intense treatment to those with a slower decline.

Many of these symptoms are more likely to be caused by something other than testicular cancer. A number of non-cancerous conditions, such as testicle injury or inflammation, can cause symptoms a lot like those of testicular cancer. Inflammation of the testicle (known as orchitis) and inflammation of the epididymis (epididymitis) can cause swelling and pain of the testicle. Both of these also can be caused by viral or bacterial infections.

Some men with testicular cancer have no symptoms at all, and their cancer is found during medical testing for other conditions. For instance, sometimes imaging tests done to find the cause of infertility can uncover a small testicular cancer.

But if you have any of these signs or symptoms, see your doctor right away.

Lump or swelling in the testicle

Most often, the first symptom of testicular cancer is a lump on the testicle, or the testicle becomes swollen or larger. (It’s normal for one testicle to be slightly larger than the other, and for one to hang lower than the other.) Some testicular tumors might cause pain, but most of the time they don't. Men with testicular cancer can also have a feeling of heaviness or aching in the lower belly (abdomen) or scrotum.

Breast growth or soreness

In rare cases, germ cell tumors can make breasts grow or become sore. This happens because certain types of germ cell tumors secrete high levels of a hormone called human chorionic gonadotropin (HCG), which stimulates breast development.

Some Leydig cell tumors can make estrogens (female sex hormones), which can cause breast growth or loss of sexual desire.

Early puberty in boys

Some Leydig cell tumors can make androgens (male sex hormones). Androgen-producing tumors may not cause any symptoms in men, but in boys they can cause signs of puberty at an abnormally early age, such as a deepening voice and the growth of facial and body hair.

Symptoms of advanced testicular cancer

Even if testicular cancer has spread to other parts of the body, many men might not have symptoms right away. But some men might have some of the following:

• Low back pain, from cancer spread to the lymph nodes (bean-sized collections of immune cells) in back of the belly.
• Shortness of breath, chest pain, or a cough (even coughing up blood) may develop from cancer spread in the lungs.
• Belly pain, either from enlarged lymph nodes or because the cancer has spread to the liver.
• Headaches or confusion, from cancer spread in the brain.

Cancer survivors can be affected by a number of health problems, but often their greatest concern is facing cancer again. If a cancer comes back after treatment it's called a recurrence. But some cancer survivors may develop a new, unrelated cancer later. This is called a second cancer.

Unfortunately, being treated for cancer doesn’t mean you can’t get cancer again. People who have had cancer can still get the same types of cancers that other people get. In fact, certain types of cancer and cancer treatments are linked to a higher risk of certain second cancers.

Common second cancers after testicular cancer

Survivors of testicular cancer can get any second cancer, but they have an increased risk of:

• A second testicular cancer (this is different than the first cancer coming back)
• Rectal cancer
• Pancreas cancer
• Bladder cancer
• Kidney cancer
• Thyroid cancer
• Acute myeloid leukemia (AML)

The most common cancer seen in testicular cancer survivors is a second testicular cancer.

Compared with most men in the general population, testicular cancer survivors are up to twice as likely to develop a new cancer outside the testicle. The chance of a second cancer changes over time and depends on which treatments were used and how old the patient was when he was treated.

If you had radiation therapy

Treatment with radiation is linked to some second cancers after testicular cancer. The risk is highest for cancers in organs in or near the area that was treated (the radiation field) -- the abdomen (belly) and pelvis, and include:

• Bladder cancer
• Colon cancer
• Rectal cancer
• Pancreas cancer
• Stomach cancer
• Kidney cancer
• Prostate cancer

If the radiation field includes the chest, there's an increased risk of:

• Lung cancer
• Esophagus cancer
• Mesothelioma (cancer of the outer lining of the lung)
• Thyroid cancer

Radiation treatments also increase the risk of melanoma skin cancer and connective tissue cancer (sarcoma).

The risks of these cancers starts going up within 5 years and doubles after 10 years in those men who were treated with radiation alone. This risk remains high and doesn’t seem to go down with time. This is why long-term follow-up is so important. The risks are generally greater with higher radiation doses or if the patient got both chemotherapy and radiation.

In recent years, radiation therapy for testicular cancer has changed. Lower doses of radiation are used, and preventive radiation treatment to the chest has been stopped. Long-term follow-up studies are needed to see if these changes have lowered second cancer risks.

If you had chemotherapy

Chemotherapy is also linked to an increased risk of second cancers, but it's slightly less than what's seen after radiation. Treatment with chemo has been linked to increased risk for these cancers:

• Kidney
• Thyroid
• Soft tissue

There's also an increased risk of leukemia and myelodysplastic syndrome (MDS) after chemotherapy for testicular cancer. Use of the chemo drug cisplatin is linked most often to leukemia and MDS, though high doses of etoposide (VP-16, Etopophos^®, or Vepesid^®) are sometimes also a factor. (The doses were higher in the past than those normally used today.) Radiation given with chemotherapy seems to increase risk even more. Leukemia and MDS are both uncommon cancers normally, so even though the risk of these cancers is higher than average, very few patients develop them from their treatment.

Follow-up after treatment

After completing treatment for testicular cancer, you should still see your doctor regularly. You may have tests for a number of years to look for signs the cancer has come back or spread. Experts don’t recommend any other testing to look for second cancers in people without symptoms. But let your doctor know about any new symptoms or problems, because they could be caused by the cancer coming back or by a new disease or second cancer.

Survivors can do regular testicular self-exams to look for cancer in the remaining testicle.

All patients should follow the American Cancer Society guidelines for the early detection of cancer, such as those for colorectal cancer.

The Children’s Oncology Group has guidelines for the follow-up of patients treated for cancer as a child, teen, or young adult, including screening for second cancers. These can be found at www.survivorshipguidelines.org.

All survivors of testicular cancer should not use tobacco and avoid tobacco smoke. Smoking increases the risk of many cancers.

To help maintain good health, survivors should also:

• Get to and stay at a healthy weight
• Adopt a physically active lifestyle
• Consume a healthy diet, with an focus on plant foods
• Limit alcohol use to no more than 2 drinks per day

These steps may help lower the risk of other cancers, too.

See Second Cancers in Adults for more information about causes of second cancers.

The American Cancer Society’s estimates for testicular cancer in the United States for 2018 are:

• About 9,310 new cases of testicular cancer diagnosed
• About 400 deaths from testicular cancer

The incidence rate of testicular cancer has been increasing in the US and many other countries for several decades. The increase is mostly in seminomas. Experts have not been able to find reasons for this. Lately, the rate of increase has slowed.

Testicular cancer is not common: about 1 of every 250 males will develop testicular cancer at some point during their lifetime.

The average age at the time of diagnosis of testicular cancer is about 33. This is largely a disease of young and middle-aged men, but about 6% of cases occur in children and teens, and about 8% occur in men over the age of 55.

Because testicular cancer usually can be treated successfully, a man’s lifetime risk of dying from this cancer is very low: about 1 in 5,000. If you would like to know more about survival statistics, see Testicular cancer survival rates.

Visit the American Cancer Society’s Cancer Statistics Center for more key statistics.

A risk factor is anything that changes your chance of getting a disease such as cancer. Different cancers have different risk factors. Some risk factors, like smoking and diet, can be changed. Others, like a person’s age or family history, can’t be changed.

But having a risk factor, or even many, does not mean that you will get the disease. Just as not having risk factors doesn’t mean you won’t get the disease. And some people who get the disease may not have had any known risk factors. Even if a person with testicular cancer has a risk factor, it’s often very hard to know how much that risk factor contributed to the cancer.

Scientists have found few risk factors that make someone more likely to develop testicular cancer. Most boys and men with testicular cancer don't have any of the known risk factors. Risk factors for testicular cancer include:

• An undescended testicle
• Family history of testicular cancer
• HIV infection
• Carcinoma in situ of the testicle
• Having had testicular cancer before
• Being of a certain race/ethnicity
• Body size

Undescended testicle

One of the main risk factors for testicular cancer is a condition called cryptorchidism, or undescended testicle(s). This means that one or both testicles fail to move from the abdomen (belly) into the scrotum before birth. Males with cryptorchidism are many times more likely to get testicular cancer than those with normally descended testicles.

Normally, the testicles develop inside the abdomen of the fetus and they go down (descend) into the scrotum before birth. But in about 3% of boys, the testicles do not make it all the way down before the child is born. Sometimes one or both testicles stay in the abdomen. In other cases, the testicles start to descend but stay in the groin area.

Most of the time, undescended testicles continue moving down into the scrotum during the child’s first year of life. If the testicle hasn't descended by the time a child is a year old, it probably isn’t going to do it on its own. Sometimes a surgical procedure known as orchiopexy is needed to move the testicle down into the scrotum.

The risk of testicular cancer might be a little higher for men whose testicle stayed in the abdomen as opposed to one that has descended at least partway. If cancer does develop, it's usually in the undescended testicle, but about 1 out of 4 cases occur in the normally descended testicle. Because of this, some doctors conclude that cryptorchidism doesn’t actually cause testicular cancer, but that there's something else that leads to both testicular cancer and abnormal positioning of one or both testicles.

Orchiopexy may reduce the risk of testicular cancer if it's done when a child is younger, but it's not as clear if it's helpful if the child is older. The best time to do this surgery is not clear. Experts in the United States recommend that orchiopexy be done soon after the child’s first birthday for reasons that aren't related to cancer (such as fertility).

Family history

Having a father or brother with testicular cancer increases the risk that you will get it, too. But only a small number of testicular cancers occur in families. Most men with testicular cancer do not have a family history of the disease.

Kleinfelter's syndrome is an inherited disease that's also linked to an increased risk of testicular cancer.

HIV infection

Some evidence has shown that men infected with the human immunodeficiency virus (HIV), particularly those with AIDS, are at increased risk. No other infections have been shown to increase testicular cancer risk.

Carcinoma in situ

This condition, described in What Is Testicular Cancer? often doesn’t cause a lump in the testicles or any other symptoms. It isn’t clear how often carcinoma in situ (CIS) in the testicles progresses to cancer. In some cases, CIS is found in men who have a testicular biopsy to evaluate infertility or have a testicle removed because of cryptorchidism. Doctors in Europe are more likely than the doctors in this country to look for CIS. This may be why the numbers for diagnosis and progression of CIS to cancer are lower in the United States than in parts of Europe.

Since we don’t know how often CIS becomes true (invasive) cancer, it isn’t clear if treating CIS is a good idea. Some experts think that it may be better to wait and see if the disease gets worse or becomes a true cancer. This could allow many men with CIS to avoid the risks and side effects of treatment. When CIS is treated, radiation or surgery (to remove the testicle) is used.

Cancer in the other testicle

A personal history of testicular cancer is another risk factor. About 3% or 4% of men who have been cured of cancer in one testicle will at some point develop cancer in the other testicle.

Age

About half of testicular cancers occur in men between the ages of 20 and 34. But this cancer can affect males of any age, including infants and elderly men.

Race and ethnicity

The risk of testicular cancer among white men is about 4 to 5 times that of black and Asian-American men. The risk for American Indians falls between that of Asians and whites. The reason for these differences is not known. Worldwide, the risk of developing this disease is highest among men living in the United States and Europe and lowest among men living in Africa or Asia.

Body size

Several studies have found that tall men have a somewhat higher risk of testicular cancer, but some other studies have not. Most studies have not found a link between testicular cancer and body weight.

Unproven or controversial risk factors

Prior injury or trauma to the testicles and recurrent actions such as horseback riding do not appear to be related to the development of testicular cancer.

Most studies have not found that strenuous physical activity increases testicular cancer risk. Being physically active has been linked with a lower risk of several other forms of cancer as well as a lower risk of many other health problems.

The exact cause of most testicular cancers is not known. But scientists have found that the disease is linked with a number of other conditions.  A great deal of research is being done to learn more about the causes.

Researchers are learning how certain changes in a cell’s DNA can cause the cell to become cancer. DNA is the chemical in each of our cells that makes up our genes. Genes tell our cells how to function. They are packaged in chromosomes, which are long strands of DNA in each cell. Most cells in the body have 2 sets of 23 chromosomes (one set of chromosomes comes from each parent), but each sperm or egg cell has only 23 chromosomes (one set). When the sperm and egg combine, the resulting embryo has a normal number of chromosomes in each cell, half of which are from each parent. We usually look like our parents because they are the source of our DNA. But DNA affects more than how we look.

Some genes control when our cells grow, divide into new cells, and die.

• Certain genes that help cells grow and divide are called oncogenes.
• Others that slow down cell division or make cells die at the right time are called tumor suppressor genes.

Cancers can be caused by changes in chromosomes that turn on oncogenes or turn off tumor suppressor genes.

Most testicular cancer cells have extra copies of a part of chromosome 12 (called isochromosome 12p or i12p). Some testicular cancers have changes in other chromosomes as well, or even abnormal numbers of chromosomes (often too many). Scientists are studying these DNA and chromosome changes to learn more about which genes are affected and how this might lead to testicular cancer.

Most testicular cancers can be found at an early stage, when they're small and haven't spread. In some men, early testicular cancers cause symptoms that lead them to seek medical attention. Most of the time a lump on the testicle is the first symptom, or the testicle might be swollen or larger than normal. But some testicular cancers might not cause symptoms until they've reached an advanced stage.

Most doctors agree that examining a man’s testicles should be part of a general physical exam during a routine check-up.

Some doctors recommend that all men examine their testicles monthly after puberty. Each man has to decide for himself whether or not to do this, so instructions for testicular exams are included in this section. If you have certain risk factors that increase your chance of developing testicular cancer (such as an undescended testicle, previous germ cell tumor in one testicle, or a family history), you should seriously consider monthly self-exams and talk about it with your doctor.

The American Cancer Society advises men to be aware of testicular cancer and to see a doctor right away if they find a lump in a testicle. Because regular testicular self-exams have not been studied enough to know if they reduce the death rate from this cancer, the ACS does not have a recommendation on regular testicular self-exams for all men.

Testicular self-exam

The best time for you to examine your testicles is during or after a bath or shower, when the skin of the scrotum is relaxed.

• Hold your penis out of the way and examine each testicle separately.
• Hold your testicle between your thumbs and fingers with both hands and roll it gently between your fingers.
• Look and feel for any hard lumps or nodules (smooth rounded masses) or any change in the size, shape, or consistency of your testicles.

It’s normal for one testicle to be slightly larger than the other, and for one to hang lower than the other. You should also be aware that each normal testicle has a small, coiled tube called the epididymis that can feel like a small bump on the upper or middle outer side of the testis. Normal testicles also contain blood vessels, supporting tissues, and tubes that carry sperm. Some men may confuse these with abnormal lumps at first. If you have any concerns, ask your doctor.

A testicle can get larger for many reasons other than cancer. For example, fluid can collect around the testicle to form a hydrocele. Or the veins in the testicle can dilate and cause enlargement and lumpiness around the testicle. This is called a varicocele. If your testicle seems larger, have a doctor examine you to be sure you have one of these conditions and not a tumor. The doctor may order an ultrasound exam (see Tests for Testicular Cancer). This is an easy and painless way of finding a tumor.

If you choose to examine your testicles regularly, you will get to know what's normal and what's different. Always report any changes to your doctor without delay.

Testicular cancer and its treatment can affect hormone levels and can also affect your ability to father children after treatment. It’s important to discuss the possible effects with your doctor before starting treatment so you are aware of the risks and what your options might be.

Most boys and men develop cancer in only one testicle. The remaining testicle usually can make enough testosterone (the main male hormone) to keep you healthy. If the other testicle needs to be removed because the cancer is in both testicles or if a new cancer develops in the other testicle, you'll need to take some form of testosterone for the rest of your life. Most often this is a gel or patch that's put on your skin or a monthly injection (shot) given in your doctor’s office. If you need testosterone supplements, talk to your doctor about what form is best for you.

Testicular cancer or its treatment can make you infertile (unable to father a child). Before treatment starts, men who might want to father children may consider storing sperm in a sperm bank for later use. But testicular cancer also can cause low sperm counts, which could make it hard to get a good sample.

Infertility can also be an issue later in life for boys who have had testicular cancer. If a boy has already gone through puberty, sperm banking is often a good option, since the frozen samples are not damaged by long periods of storage. Researchers are also looking at techniques that might allow younger boys to father children someday.

In some cases, if one testicle is left, fertility returns after the testicular cancer has been treated. For example, fertility typically returns about 2 years after chemotherapy stops.

Even when sperm counts in semen are very low, men have several options for fathering children. Be sure to discuss any fertility concerns with your doctor before your treatment begins.

For more information, see Fertility and Men With Cancer.