From the Guidelines
Seminoma patients may show low levels of human chorionic gonadotropin (hCG) in serum, but significantly elevated hCG levels are more characteristic of non-seminomatous germ cell tumors, and placental alkaline phosphatase (PLAP) is not commonly measured in serum for seminoma diagnosis or monitoring.
Key Points
- Approximately 10-25% of pure seminomas may produce low levels of hCG that can be detected in serum 1.
- Elevated hCG levels are more characteristic of non-seminomatous germ cell tumors, and significantly elevated serum hCG in a seminoma patient often suggests either the presence of syncytiotrophoblastic elements within the seminoma or a mixed germ cell tumor component.
- Serum tumor markers including alpha-fetoprotein (AFP), hCG, and lactate dehydrogenase (LDH) are routinely measured in testicular cancer patients, with AFP typically negative in pure seminoma while LDH may be elevated 1.
- These markers are valuable for diagnosis, staging, and monitoring treatment response in seminoma patients, and decisions to treat should not be based solely on mildly elevated AFP or beta-hCG values 1.
Clinical Implications
- The presence of significantly elevated serum hCG in a seminoma patient should prompt further evaluation to rule out non-seminomatous germ cell tumor components or other underlying conditions.
- Serum tumor marker measurements, including hCG, should be interpreted in the context of clinical presentation, imaging findings, and other diagnostic tests to guide treatment decisions.
- The NCCN guidelines recommend against treating patients based on an elevated LDH alone, and emphasize the importance of considering multiple factors, including tumor markers, imaging, and clinical presentation, when making treatment decisions 1.
From the Research
Seminoma Markers
- PLAP and hCG are markers that can be associated with seminoma, a type of testicular cancer.
- Studies have shown that these markers can be elevated in patients with seminoma, although their predictive value and correlation with disease status can vary.
PLAP in Seminoma
- A study published in 1983 found that serum levels of PLAP were elevated in 9 out of 21 patients with primary seminoma, and in 9 out of 12 patients with recurrent or metastatic disease 2.
- Another study published in 1996 found that serum PLAP was increased initially in about 50% of patients with seminoma, and that a combination of PLAP, LDH, and HCG-B markers resulted in a positive identification rate of 82% of patients with seminoma 3.
hCG in Seminoma
- A study published in 1992 found that patients with seminoma had normal serum AFP and sporadically slightly elevated hCG 4.
- A study published in 1994 found that elevated beta-hCG levels were noted prior to orchiectomy in 30.2% of patients with pure seminoma, and that these levels returned to normal in 76% of these patients after orchiectomy 5.
- A study published in 2005 found that an elevated pre-treatment beta-hCG level appeared to have neither importance nor predictive value in stage I seminoma 6.