Germ cells are the cells that develop into eggs in females and sperm in males. Germ cell cancer arises when these reproductive cells grow uncontrollably, forming a tumor. While these tumors originate from reproductive cells, they can appear in various parts of the body. This occurs because, during embryonic development, germ cells sometimes migrate to other areas. The resulting tumors can be noncancerous (benign) or cancerous (malignant).
Types and Locations of Germ Cell Tumors
Germ cell tumors are classified into two main categories: seminomas and non-seminomas. Seminomas are slower-growing tumors, while non-seminomas tend to grow more quickly. Non-seminomas encompass several subtypes, including:
- Embryonal carcinoma
- Yolk sac tumors
- Choriocarcinomas
- Teratomas
Teratomas are a subtype that can contain various types of developed tissue, such as hair, muscle, and bone. They can be mature, which are usually benign, or immature, which have a higher likelihood of being cancerous. It is also common for tumors to be composed of a mixture of different germ cell types, which are referred to as mixed germ cell tumors.
The location of germ cell tumors separates them into gonadal and extragonadal types. Gonadal tumors form in the reproductive organs—the testes in males and the ovaries in females. These are the most common sites for these tumors to develop.
Extragonadal tumors develop in other parts of the body along the body’s midline. Common sites include:
- The mediastinum (the area in the chest between the lungs)
- The retroperitoneum (the back of the abdomen)
- The lower spine
- The brain
Symptoms and Risk Factors
The symptoms of a germ cell tumor depend on its location and size. A tumor in a testicle often presents as a painless lump or swelling. When located in an ovary, symptoms might include abdominal pain, bloating, or pressure in the pelvis.
If a tumor develops in the chest (mediastinum), it can cause chest pain, shortness of breath, or a persistent cough. Certain germ cell tumors produce hormones, leading to specific symptoms. For example, some tumors produce human chorionic gonadotropin (hCG), which may cause breast growth in males. A tumor pressing on nerves in the lower back can also lead to leg weakness.
Several factors increase the risk of developing germ cell tumors. A primary risk factor for testicular germ cell tumors is an undescended testicle, a condition known as cryptorchidism. A family history of germ cell tumors also elevates an individual’s risk.
Certain genetic conditions are associated with a higher incidence of these tumors. Klinefelter syndrome, a condition where a male is born with an extra X chromosome, is one such example. Other genetic conditions affecting sex chromosome development, like Swyer syndrome and Turner syndrome, have also been linked to an increased risk.
Diagnosis and Staging
A diagnosis of germ cell cancer involves a combination of tests. Blood tests are used to check for specific tumor markers, which are substances released by the tumors. Elevated levels of markers like alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and lactate dehydrogenase (LDH) can indicate a germ cell tumor and help differentiate between types.
Imaging studies are used to locate and determine the size of the tumor. An ultrasound is often the first imaging test for a suspected testicular tumor. Computed tomography (CT) scans of the chest, abdomen, and pelvis help identify if the cancer has spread. Magnetic resonance imaging (MRI) may be used for tumors in the brain or spinal cord.
While blood tests and imaging provide strong evidence, a biopsy is the definitive method for confirming a cancer diagnosis. During a biopsy, a small sample of tissue is removed from the tumor and examined under a microscope. This analysis confirms the presence of cancer and identifies the specific type of germ cell tumor.
Once cancer is confirmed, staging determines the extent of the cancer’s spread. Stage I indicates the cancer is confined to its original location. Stage II means it has spread to nearby lymph nodes, while Stage III indicates more extensive lymph node involvement or spread to distant sites. Stage IV signifies that the cancer has metastasized to distant organs.
Common Treatment Approaches
The primary treatment approaches for germ cell tumors are surgery, chemotherapy, and radiation therapy. The specific plan is determined by the tumor’s type, location, and stage.
Surgery is a common treatment with the goal of removing the tumor. For testicular cancer, this involves the removal of the affected testicle, a procedure called an orchiectomy. For an ovarian germ cell tumor, the surgeon may remove the tumor while preserving the ovary, or remove the entire ovary and fallopian tube. Surgery for extragonadal tumors aims to remove as much of the tumor as possible.
Chemotherapy is a foundational treatment, particularly when the cancer has spread. It uses drugs to destroy cancer cells throughout the body. A common chemotherapy regimen for germ cell tumors is BEP, which consists of the drugs bleomycin, etoposide, and cisplatin. The number of chemotherapy cycles depends on the stage and type of the tumor.
Radiation therapy uses high-energy rays to target and kill cancer cells. This treatment is more commonly used for seminomas than for non-seminomas, as seminomas are sensitive to radiation. It may be directed at specific areas, such as lymph nodes in the abdomen, to eliminate any cancer cells that may have spread there.
Prognosis and Post-Treatment Care
The outlook for individuals with germ cell cancers is positive, as these cancers are highly treatable. Cure rates are high, particularly when the cancer is detected in its early stages. For instance, testicular cancer has a five-year survival rate of over 95%. Even when diagnosed at an advanced stage, effective treatments often lead to successful outcomes.
Long-term follow-up care is an important part of the recovery process. This involves a regular schedule of check-ups with an oncologist. These appointments include physical exams, blood tests to monitor tumor markers, and imaging studies like CT scans. This surveillance is designed to detect any signs of cancer recurrence.
Treatment for germ cell cancer, particularly chemotherapy and radiation, can impact fertility. Because these cancers often affect young people, discussions about fertility preservation are a standard part of the pre-treatment process. Options such as sperm banking for males and egg or embryo freezing for females allow individuals to preserve their ability to have children. These options are explored before treatment begins.