Testicular Germ Cell Cancer

Testicular germ cell cancer is a highly treatable form of cancer that primarily affects young men, with most cases occurring between ages 15 and 35. Understanding this disease, its warning signs, and treatment options can make a crucial difference in outcomes.

Table of contents

• What is Testicular Germ Cell Cancer?
• Types of Testicular Germ Cell Cancer
• Who is Affected?
• Signs and Symptoms
• How is it Diagnosed?
• Treatment Options
• Outlook and Survival

What is Testicular Germ Cell Cancer?

Testicular germ cell cancer is a disease in which malignant (cancerous) cells form in the tissues of one or both testicles. The testicles are two egg-shaped glands located inside the scrotum, a sac of loose skin that lies directly below the penis. These glands are the male sex glands and produce sperm and the hormone testosterone^[1].

More than 90% of testicular cancers start in the germ cells, which are cells in the testicles that develop into sperm^[3][4]. This type of cancer is known as testicular germ cell cancer. Although testicular cancer accounts for approximately 1% of all malignancies in men, it is the most common cancer in men ages 15 to 35^[3][5].

The incidence of testicular germ cell cancer has been rising in many countries, including Europe and the United States^[3]. Despite this increase, there is promising news: testicular germ cell cancer has become a model of curable cancer, with curability expected in about 95% of all patients diagnosed with the disease^[12].

Types of Testicular Germ Cell Cancer

Testicular germ cell tumors can be classified as either seminomas or nonseminomas, which may be identified by looking at cells under a microscope^[3]. These two types respond to treatment differently and have different patterns of growth and spread.

Seminomas are slow-growing cancers that primarily affect people in their 40s or 50s. They often grow and spread more slowly than nonseminomas and are more sensitive to radiation treatment^[1][13]. Around 55 to 60 out of every 100 testicular cancers are pure seminomas^[6].

Nonseminomas are cancers that grow more rapidly than seminomas. They typically grow and spread more quickly and mainly affect people in their late teens, 20s, and early 30s^[3][13]. There are four types of nonseminoma tumors, each named after the type of germ cell that makes up the tumor. These include embryonal carcinoma, yolk sac carcinoma, choriocarcinoma, and teratoma^[13].

Some testicular cancer tumors consist of both seminoma and nonseminoma cells. These are called mixed germ cell tumors^[6]. A testicular germ cell tumor that contains a mix of both these subtypes is classified and treated as a nonseminoma^[3].

Who is Affected?

Testicular germ cell cancer is rare, comprising only 1 to 2% of all tumors in males^[3]. However, it is the most common cancer in men between the ages of 15 and 35^[3][5]. Testicular cancer can affect anyone, but infants, children, teens, and young adults get it most often^[1].

Several factors may increase the risk of developing testicular cancer. Men who have an undescended testicle (a condition where the testicle doesn’t drop into the scrotum before birth) have a greater risk, even if they have surgery to correct it^[5][13]. A family history of testicular cancer, particularly in a father or brother, also increases risk^[5][13].

Men who have had testicular cancer in one testicle have an increased likelihood of developing a second cancer in the other testicle^[13]. Testicular cancer is more common among white men in the United States and Europe compared to men of other racial and ethnic backgrounds^[5][13].

Signs and Symptoms

The most common sign of testicular cancer is a painless lump in the testicle^[5][13]. Other symptoms may include swelling or sudden fluid buildup in the scrotum, a lump or swelling in either testicle, a feeling of heaviness in the scrotum, or a dull ache in the lower belly or groin^[5][13].

Some men may also experience pain or discomfort in a testicle or the scrotum, or notice a shrinking testicle^[13]. In some cases, men may notice enlargement or tenderness of the breast tissue^[5].

These symptoms can occur with other conditions that are not cancer, so there’s no need to panic if you notice them. However, it’s important to schedule a visit with a healthcare provider to be sure. Delays in diagnosis allow cancer cells time to spread, making the disease harder to treat^[13].

How is it Diagnosed?

To diagnose testicular cancer, doctors use several tests that examine the testicles and blood^[18]. The process typically begins with a physical exam in which a doctor checks for lumps, swelling, or pain in the testicles^[15].

A testicular ultrasound uses sound waves to create pictures of the scrotum and testicles. This test helps the doctor see whether lumps look like cancer or something else, and whether the lumps are inside or outside the testicle. Lumps inside the testicle are more likely to be testicular cancer^[15].

Blood tests can detect proteins made by testicular cancer cells. This type of test is called a tumor marker test. Tumor markers for testicular cancer include beta-human chorionic gonadotropin (beta-hCG), alpha-fetoprotein (AFP), and lactate dehydrogenase (LDH)^[10][15]. These markers play an important role in staging and monitoring germ cell tumors and should be measured before removing the involved testicle^[10].

If a healthcare provider thinks a lump on the testicle may be cancerous, surgery to remove the testicle may be performed. The testicle is sent to a lab for testing to determine whether it’s cancerous^[15]. This procedure is called an orchidectomy and is the main treatment for testicular cancer^[11].

Treatment Options

Treatment for testicular cancer depends on the size and type of cancer, whether it has spread, and the patient’s general health^[11]. It will usually include surgery to remove the testicle, which may be the only treatment needed, or patients may also have chemotherapy or radiotherapy^[11].

Surgery to remove the testicle (orchidectomy) is the main treatment for testicular cancer and may be the only treatment needed^[11]. Patients are usually given the choice to have an artificial testicle put in. Having a testicle removed does not usually affect fertility^[11]. Patients might also have surgery to remove lymph nodes (small glands that are part of the body’s immune system) in the belly if the cancer has or might have spread to them^[11].

Chemotherapy uses medicines to kill cancer cells. Patients may have chemotherapy after surgery to help stop the cancer coming back, or if the cancer has come back or spread to other parts of the body^[11]. The most widely used chemotherapeutic regimen for metastatic disease is bleomycin, etoposide, and cisplatin (BEP)^[17].

Radiotherapy uses high-energy rays of radiation to kill cancer cells. Patients may have radiotherapy if they have a certain type of testicular cancer (seminoma) and the cancer has spread to the lymph nodes in the belly^[11]. Seminomas are more sensitive to radiation than nonseminomas^[1].

Some treatments for testicular cancer, such as chemotherapy, can affect fertility. This means patients might not be able to have children in the future. Before starting treatment, patients are offered the option to collect and store sperm, a process called sperm banking. In the future, this stored sperm can be used in fertility treatment^[11].

Outlook and Survival

Testicular cancer is highly treatable, and testicular cancer that’s diagnosed and treated early has an excellent cure rate^[13]. For patients with seminomas (all stages combined), the cure rate exceeds 90%. For patients with low-stage seminomas or nonseminomas, the cure rate approaches 100%^[10].

Because of advances in diagnostic procedures, sophisticated radiation techniques, and especially the introduction of cisplatin-based chemotherapy protocols together with advanced post-chemotherapy surgical techniques, curability is expected in about 95% of all patients diagnosed with testicular cancer and over 70% of patients with advanced disease^[12].

Several factors affect prognosis and treatment options. Where the cancer started plays a role—nonseminomas that start in the testicle or in the back of the abdomen have a better prognosis than those starting in the chest^[3]. The type of germ cell tumor matters, as seminomas often respond better to treatment than nonseminomas^[25].

Where the cancer spreads is also important. Testicular cancer that has spread to organs other than the lungs usually has a poorer prognosis^[25]. For nonseminomas, tumor marker levels in the blood are considered when estimating prognosis, with high tumor marker levels linked to a poorer prognosis^[25].

In 2013, about 8,000 American men were estimated to be diagnosed with testicular germ cell cancer, and of those, 370 were predicted to die from the disease^[3]. Despite the increase in incidence rate, the promising circumstance is that testicular germ cell cancer has become a model of curable cancer^[12].

germ cell tumor, seminoma, nonseminoma, testicular cancer, TGCT

• Testicles
• Scrotum
• Germ cells
• Retroperitoneal lymph nodes