Non-seminoma is a type of germ-cell testicular cancer. Treatment may include surgery to remove a testicle, lymph node removal, and chemotherapy.

Most cases of testicular cancer develop from germ cells, which are the cells that produce sperm. The two types of germ cell tumors are non-seminoma and seminoma.

This article looks at non-seminoma testicular cancer, including its subtypes, diagnosis, treatment, and outlook.

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Non-seminoma testicular cancer is a type of germ cell tumor. Over 90% of testicular cancers begin in germ cells.

There are two main types of germ cell tumors in testicular cancer — seminomas and non-seminomas.

Non-seminomas develop from germ cells, which are more mature and specialized than they are typically. This type of testicular cancer is more common in males in their mid–30s.

Subtypes

Doctors classify non-seminomas further into different subtypes:

  • Embryonal carcinoma: These tumors appear similar to embryo tissue under a microscope. This subtype of non-seminoma can quickly grow and may spread outside of the testicle.
  • Yolk sac carcinoma: These tumors have cells that look similar to the yolk sac in an early embryo. Yolk sac carcinoma is rare in adults but is the most common type of testicular cancer in children. However, this disease responds well to chemotherapy.
  • Choriocarcinoma: This is a rare type of non-seminoma that can grow and spread rapidly to other areas of the body.
  • Teratoma: These tumors are rare and have cells that look similar to the three layers of an embryo. Mature teratomas rarely spread but may recur, and immature teratomas may spread or recur. Teratomas with somatic-type malignancy are particularly rare.

People will sometimes have pure forms of these subtypes, but germ cell tumors usually have a mix of non-seminoma cells, which may respond better to treatments than pure forms.

Non-seminomas and seminomas account for up to 98% of all testicular germ cell tumors, and both types occur at similar rates.

Non-seminomas occur at around the same frequency as seminomas, although seminomas are slightly more common. Non-seminomas usually affect males between the late teens and early 30s.

Symptoms of non-seminoma testicular cancer may include the following:

  • a painless lump or swelling in the testicles
  • a dull pain in the testicles or scrotum, although pain may sometimes feel sudden and severe
  • infertility

Up to 35% of people with non-seminomas may have issues with sperm production. This may cause low sperm counts and decreased sperm motility which can cause infertility.

Some theories suggest the following factors in pregnancy may increase the risk of germ cell tumors, although these require further evidence:

  • higher exposure to estrogen
  • exposure to certain pesticides or organic pollutants
  • occupations including aircraft maintenance and firefighting

Risk factors for testicular cancer in general include:

  • cryptorchidism, or an undescended testicle
  • a family history of testicular cancer
  • HIV infection, particularly AIDS
  • carcinoma in situ, which are atypical cells that may develop into testicular cancer
  • being taller
  • age, with around half of testicular cancer cases occurring in those between 20 and 34 years of age
  • race and ethnicity, with a higher risk in American Indian, white, and Alaska Native males

To diagnose and identify the type of non-seminoma, doctors may carry out the following:

  • Physical examinations: These feel for any lumps, swelling, or tenderness in the testicles, as well as any signs that cancer has spread, such as swollen lymph nodes.
  • Blood tests for tumor markers: These include alpha-fetoprotein, human chorionic gonadotropin, and lactic dehydrogenase, which may be high with non-seminoma testicular cancer.
  • Ultrasound of the testicles: These show if a lump is present and if it is a solid tumor, which can indicate cancer.
  • CT scan with contrast dye: This scans the abdominal and pelvic area and may also include a chest and brain scan to check if the cancer has spread.

Surgery to remove the cancerous testicle is generally the standard treatment for nearly all types of testicular cancer. The term for this procedure is radical inguinal orchiectomy.

A surgeon will make an incision above the pubic area to remove the testicle and spermatic cord from the scrotum.

Doctors will also examine the removed tissue under a microscope. This can help identify the type and extent of the cancer.

People may also have retroperitoneal lymph node dissection (RPLND), which removes surrounding lymph nodes. RPLND with chemotherapy is a key treatment for low stage non-seminomas. The technique may help prevent the spread of non-seminoma and can lead to a high cure rate.

In addition to surgery, people may also have chemotherapy. Non-seminomas are the most responsive type of testicular cancer to cisplatin, a chemotherapy drug. Alternatively, doctors may recommend taking bleomycin and etoposide.

Side effects of treatment for non-seminoma testicular cancer

Treatments can have side effects, and chemotherapy or radiation therapy may increase the risk of secondary cancers or lung injury.

Treatments for testicular cancer may affect fertility. Chemotherapy treatment for non-seminoma may reduce fertility by around 30%.

In most cases, people will have azoospermia, an absence of sperm in the semen, for at least 2–3 years after chemotherapy.

Removal of one testicle will not usually affect sex or the ability to have an erection, but removing both testicles will cause infertility.

Before any treatment, it is important to discuss sperm banking if people may want to conceive in the future. A person may also wish to consider a testicular prosthesis.

Factors, such as tumor marker levels after surgery and whether the cancer has spread, can affect outlook.

In 56% of non-seminoma cases, there is a positive outlook, with a 5-year progression-free survival of 89% with a 5-year overall survival of 92%.

The following are answers to common questions about non-seminoma testicular cancer.

How does it differ from seminoma testicular cancer?

Non-seminomas and seminomas are both forms of germ cell tumors. Seminoma germ cell tumors turn cancerous early on in their development. Types of seminoma tumors include anaplastic, classic, or spermatocytic.

Classic seminomas are most common in males in their 40s. Spermatocytic seminomas are more common over the age of 50 and do not usually spread. Anaplastic seminomas can be more aggressive to treat and are more likely to spread.

Non-seminomas occur due to cells that are more specialized and mature than typical germ cells. Non-seminomas are more common in males in their mid-30s. There are different subtypes of non-seminomas, and non-seminomas may have a mix of different cells.

Does non-seminoma testicular cancer have a worse outlook than seminoma testicular cancer?

According to a 2020 article, non-seminomas tend to be more aggressive than seminomas as they can grow and spread more quickly. They are also less responsive to radiation therapy.

What type of testicular cancer has the most positive outlook?

Seminomas usually have a better response to treatment compared to non-seminomas, so they may have a more positive outlook.

Testicular cancer that has spread to other areas of the body may also have a more negative outlook. Factors, such as tumor marker levels and where the tumor started, are also important for the outlook of non-seminoma tumors.

Non-seminoma testicular cancer is a type of germ cell tumor, which is the most common type of testicular cancer. Non-seminoma and seminoma tumors occur at a similar rate.

Treatment for non-seminomas usually includes surgery to remove the testicle and additional chemotherapy and may also involve lymph node removal.