Testicular cancer (TC) arises from germ cells, the cells that produce sperm, and is the most common cancer in young men. While a blood test cannot be used as a standalone screening tool to initially detect the disease, it plays a supportive role in management. Blood tests measure specific substances released by cancer cells, helping doctors confirm a diagnosis, determine the extent of the disease, and monitor treatment effectiveness. This method is utilized alongside physical exams and imaging studies.
Key Blood Markers for Testicular Cancer
Specific proteins and enzymes, known as tumor markers, are often elevated in the blood of individuals with testicular cancer. The three primary markers are human chorionic gonadotropin (hCG), alpha-fetoprotein (AFP), and lactate dehydrogenase (LDH). These markers are products of the tumor cells themselves, and their presence helps classify the type of germ cell tumor present. The half-lives of these substances (AFP: 5 to 7 days; hCG: 24 to 36 hours) are used to track their decline after treatment.
Human chorionic gonadotropin is a glycoprotein hormone typically associated with pregnancy. However, certain testicular cancer cells can also produce it, as germ cell tumors can transform into syncytiotrophoblasts. Elevated hCG levels can be seen in both seminoma and non-seminoma tumor types, although it is more common in the latter.
Alpha-fetoprotein is a protein normally produced by the fetal yolk sac and liver during development. In adults, its elevation is strongly correlated with non-seminomatous germ cell tumors (NSGCTs), particularly those containing yolk sac tumor or embryonal carcinoma components. Pure seminoma, the most common type of testicular cancer, does not secrete AFP; therefore, any measurable level of AFP indicates a non-seminoma component is present.
Lactate dehydrogenase is a general enzyme found in nearly every tissue in the body, making it the least specific of the three markers for testicular cancer. However, its measurement is useful because elevated levels often correspond to a high tumor burden or large mass of cancerous cells. LDH is used as a prognostic indicator, with higher concentrations suggesting a less favorable outlook, particularly in advanced cases.
Applying Blood Tests in Diagnosis and Surveillance
Blood tests for tumor markers are not sensitive or specific enough for mass screening. Not all testicular cancers elevate these markers, and non-cancerous conditions, such as liver disease, can cause levels to rise. The tests are primarily used once a suspicious mass has been identified.
In the diagnostic phase, marker levels are taken before the surgical removal of the testicle. These initial levels are crucial for staging the disease and determining the extent of the cancer’s spread. Persistently elevated markers after surgery suggest that cancer cells remain in the body, even if they are not visible on imaging scans.
The most significant application is in post-treatment surveillance and monitoring for recurrence. After successful treatment, doctors track the markers to ensure they remain within the normal range. A sudden rise in AFP or hCG can be the first indication that the cancer has returned, often months before a new mass is detectable through imaging.
Monitoring the rate at which marker levels fall following chemotherapy or surgery assesses treatment effectiveness. If levels fail to decline with the expected half-life, it suggests the cancer is resistant or that all cancerous tissue was not successfully removed. Marker monitoring combined with regular imaging and physical exams forms the standard follow-up protocol.
Essential Steps for Initial Identification
Because blood tests are supplementary, the first step in identification is the physical detection of a potential mass. This begins with regular self-examination, where an individual checks the testicles for any unusual changes. A testicular cancer mass is typically felt as a hard, firm, or pea-sized lump, often painless, located on the side or front of the testicle.
If a change is noticed, a physical examination by a healthcare provider is the next step. The doctor will carefully feel the testicles, scrotum, and groin for any lumps or swelling. The examination helps distinguish a potentially cancerous lump from other benign conditions, such as fluid-filled cysts or inflammation.
The definitive non-invasive method for initial diagnosis is the testicular ultrasound. This imaging test uses sound waves to create a detailed picture of the internal structures. An ultrasound confirms the presence of a mass and determines if it is solid (suggesting high potential for cancer) or fluid-filled (usually benign). The final diagnosis requires the surgical removal of the affected testicle and laboratory analysis of the tissue.