Definition

Seminoma is a type of cancer that originates from germ cells in men. Seminomas most commonly occur in the testicles but can also develop in other areas of the body, such as the brain, chest, or abdomen. Seminomas tend to grow and spread slowly.

Testicular germ cell tumors are the most common malignancies in young men, found in 5 out of 100,000 men. However, these tumors account for only 1% of all tumors in men. The incidence of testicular tumors has been increasing over the past 20 years. In the United States, testicular seminoma is the most common subtype of testicular cancer. The incidence of seminoma is higher in white populations compared to African Americans. This rate has been increasing among white populations over the past few decades.

Testicular germ cell tumors have several subtypes but can be divided into seminoma and non-seminoma, each with different therapies. Seminomas are one of the types of cancer that can be treated and have a high cure rate of 95% if treated at an early stage.

Causes

The exact cause of seminoma is unknown. However, tumors or cancers can form due to changes or abnormalities in the chromosomes that control cell growth and death. Experts are still studying DNA and chromosomal changes that cause testicular cancer.

Risk Factor

Several factors are associated with an increased risk of seminoma, including:

• Age. Seminoma usually occurs in young men between the ages of 15 and 34.
• History of cryptorchidism (testicles that do not descend into the scrotum). The risk of seminoma increases with a history of cryptorchidism. There is a 10-40 fold increased risk of seminoma in people with cryptorchidism. About 10% of those with cryptorchidism develop germ cell tumors. Testicles located in the abdomen usually develop seminomas, while testicles placed in the scrotum via surgery usually develop non-seminomas.
• Environmental exposure. Exposure to chemicals such as organochlorines, polychlorinated biphenyls, polyvinyl chlorides, phthalates, marijuana, and tobacco is associated with an increased risk of seminoma or other germ cell tumors.
• Infection. A history of mumps or parotitis infection is linked to an increased risk of germ cell tumors.
• Other factors. These include injury, estrogen exposure during pregnancy, a family history of testicular tumors, intersex syndromes (androgen insensitivity syndrome and gonadal dysgenesis), and a history of cancer in the other testis.

Symptoms

Seminoma is usually characterized by a painless lump or swelling in the testicle. This may be discovered accidentally by you or your partner. Sometimes this lump causes dull pain or a feeling of heaviness in the lower abdomen, the area between the penis and anus, or the scrotum. Although rare, sudden pain or blood in the sperm can occur.

In advanced disease that has spread, symptoms may include:

• Lumps in the lymph nodes of the neck or upper chest
• Cough or shortness of breath (spread to the lungs)
• Loss of appetite
• Weight loss
• Nausea
• Vomiting
• Gastrointestinal bleeding (spread to the gastrointestinal tract)
• Bone pain (spread to bones)
• Headaches, seizures, muscle weakness (spread to the brain, spinal cord, or peripheral nerves)

Diagnosis

If you have a testicular lump, the doctor will begin by asking about your symptoms and medical history, including any history of cryptorchidism. The doctor will then perform a physical examination, focusing on your testicles. Laboratory and radiological tests will also be required.

• Laboratory tests. Tumor cells produce substances that can be detected in blood tests. For seminoma, tumor markers such as alpha-fetoprotein (AFP), beta-chorionic gonadotropin (beta-HCG), and lactate dehydrogenase (LDH) can be checked. Beta-HCG and LDH levels will be elevated in seminoma, while AFP will not. Beta-HCG levels will increase in 5-10% of seminoma patients, and these levels may be associated with cancer spread.
• Radiological imaging. Scrotal ultrasound (USG) is performed to rule out other possible causes.

The most definitive diagnosis is made by removing the testis, a procedure that serves both diagnostic and therapeutic purposes. The removed testis is sent to a laboratory for microscopic examination (histological examination). This examination confirms the presence of seminoma and helps distinguish it from other types of testicular cancer.

After diagnosis, chest X-rays or CT scans, abdominal and pelvic CT scans, brain MRI, and bone scans will be performed to detect cancer spread based on the stage of the disease and symptoms of cancer spread. PET scans can be used to assess disease activity after chemotherapy and to detect recurrence.

Management

The standard treatment for seminoma is the surgical removal of the testis, which serves both diagnostic and therapeutic purposes for all stages of seminoma. After surgery, additional treatments such as chemotherapy or radiotherapy may be given, depending on the stage of the disease.

In general, treatment based on the stage includes:

• Stage 1. For stage 1 seminoma, surgical removal of the testis is usually sufficient for a cure. After surgery, options include observation only, single-dose carboplatin infusion chemotherapy, or preventive radiotherapy.
• Stage 2. After removal of the testis and inguinal lymph nodes, treatment for stage 2 depends on the extent of lymph node involvement. Radiotherapy with or without chemotherapy is recommended.
• Stage 3. For stage 3 seminoma, chemotherapy with bleomycin, etoposide, and cisplatin (BEP) or etoposide and cisplatin (EP) is preferred. Radiotherapy may be used in certain cases.

After treatment, lifelong follow-up is required to monitor the disease, which may include:

• Consultation and physical examination by a doctor
• Laboratory tests for tumor markers (beta-HCG, LDH, AFP)
• Chest X-ray
• Abdominal CT scan, with or without pelvic CT scan The frequency of monitoring will be determined based on the disease stage.

Complications

If not treated properly, the tumor can spread and cause severe disease. Common sites of spread are the lungs, lymph nodes, liver, and bones. Additionally, radiation and chemotherapy have long-term complications, including:

• Nerve disorders. Peripheral nerve disorders are a common side effect of chemotherapy, affecting 20-40% of patients, causing pain and permanent sensory loss.
• Heart and vascular disease. Chemotherapy with cisplatin increases the risk of heart disease.
• Fertility problems. Chemotherapy and radiation can decrease sperm count and cause fertility problems. Therefore, doctors usually offer sperm storage at a sperm bank before chemotherapy or radiation.
• Hearing problems. Cisplatin can cause permanent hearing loss and ringing in the ears.
• Secondary tumors. Chemotherapy and radiotherapy can increase the risk of secondary cancers. Etoposide can cause leukemia, with risk proportional to the dose given.

Prevention

Testicular tumors cannot be prevented, but self-examinations can help identify changes in the testicles that should be consulted with a doctor. Many experts recommend monthly self-examinations of the testicles.

When to See a Doctor?

You should consult a doctor if you notice any changes in your testicles, such as swelling or a lump in one of the testicles. A lump in the scrotum can have various causes. If you have a testicular tumor, the sooner treatment begins, the greater your chance of a complete recovery.