Current status of tumor markers in testicular cancer. A practical review

Serum Tumour Markers in Testicular Germ Cell Tumours: Frequencies of Elevated Levels and Extents of Marker Elevation Are Significantly Associated with Clinical Parameters and with Response to Treatment

Introduction

Although serum tumor markers beta human chorionic gonadotropin (bHCG), alpha-fetoprotein (AFP), and lactate dehydrogenase (LDH) are well-established tools for the management of testicular germ cell tumours (GCTs), there are only few data from contemporary cohorts of primary GCT patients regarding these biomarkers. Our aim was to evaluate marker elevations in testicular GCTs and to document their associations with various clinical characteristics.

Patients and Methods

A total of 422 consecutive patients with GCTs were retrospectively analysed regarding serum levels of bHCG, AFP, and LDH during the course of treatment. Additionally, the following characteristics were recorded: histology, age, laterality, clinical stage (CS), pT-stage, and tumour size. Marker elevations were first tabulated in dichotomized way (elevated: yes/no) in various subgroups and second as continuous measured serum values. Descriptive statistical methods were employed to look for differences among subgroups and for associations of elevations with clinical parameters.

Results

In all GCT patients, the frequencies of elevated levels of bHCG, AFP, LDH, and bHCG or AFP were 37.9%, 25.6%, 32.9%, and 47.6%; in pure seminomas 28%, 2.8%, 29.1%, and 30.3%; and in nonseminoma 53.0%, 60.1%, 38.7%, and 73.8%. Significant associations were noted with pT-stages >pT1, clinical stages >CS1, tumour size, and younger age. Frequencies of marker elevations dropped significantly after treatment, but LDH levels remained elevated in 30.5%-34.1%. Relapsing patients (n=27) had elevated levels of bHCG, AFP, and LDH in 25.9%, 22.2%, and 29.6%, respectively, thirteen of whom with a changed marker pattern.

Conclusions

The classical GCT-biomarkers correlate with treatment success. Clinical utility is limited due to proportions of < 50% of patients with elevated levels and the low specificity of LDH. The elevation rates are significantly associated with histology, clinical and pT-stages, tumour size, and younger age. Individual marker patterns may change upon relapse. Clinically, ideal biomarkers are yet to be found.

Utility of serum tumor markers during surveillance for stage I seminoma

BACKGROUND

The serum tumor markers α-fetoprotein (AFP), β-human chorionic gonadotropin (HCG), and lactate dehydrogenase (LDH) are often measured as part of surveillance protocols in patients with stage I seminoma. In this study, the authors evaluated the utility of routine measurement of these markers in the detection of disease relapse.

METHODS

Data were gathered from a prospectively maintained database of patients who underwent surveillance for stage I testicular seminoma diagnosed between 1982 and 2005 at Princess Margaret Hospital. Patients were followed on a predefined schedule with physical examination (PE), serum tumor markers, abdominopelvic computed tomography, and chest x-rays. The records of patients who relapsed were examined for details of imaging and serum tumor markers throughout the period of follow-up until the time of relapse.

RESULTS

Of the 527 patients who were managed by surveillance, 75 patients (14%) relapsed at a median follow-up of 72 months. Of these, 65 patients relapsed within the first 3 years and had routine serum tumor markers measured. In total, 11 patients had abnormal tumor markers at the time of relapse (AFP, 0 patients; HCG, 6 patients; LDH, 4 patients; and HCG and LDH, 1 patient). Only 1 patient had an elevated tumor marker (LDH) before relapse, as defined by an abnormal imaging study (n = 64) or physical examination (n = 1), for which the treatment and outcome were not affected.

CONCLUSIONS

Serum tumor marker levels did not aid in the early diagnosis of disease relapse in patients with stage I seminoma who were managed with surveillance. The current results indicated that routine measurement of serum tumor markers can be discontinued safely in seminoma surveillance schedules.

American Society of Clinical Oncology Clinical Practice Guideline on Uses of Serum Tumor Markers in Adult Males With Germ Cell Tumors

Purpose

To provide recommendations on appropriate uses for serum markers of germ cell tumors (GCTs).

Methods

Searches of MEDLINE and EMBASE identified relevant studies published in English. Primary outcomes included marker accuracy to predict the impact of decisions on outcomes. Secondary outcomes included proportions of patients with elevated markers and statistical tests of elevations as prognostic factors. An expert panel developed consensus guidelines based on data from 82 reports.

Results

No studies directly compared outcomes of decisions with versus without marker assays. The search identified few prospective studies and no randomized controlled trials; most were retrospective series. Lacking data on primary outcomes, most Panel recommendations are based on secondary outcomes (relapse rates and time to relapse).

Recommendations

The Panel recommended against using markers to screen for GCTs, to decide whether orchiectomy is indicated, or to select treatment for patients with cancer of unknown primary. To stage patients with testicular nonseminomas, the Panel recommended measuring three markers (α-fetoprotein [AFP], human chorionic gonadotropin [hCG], and lactate dehydrogenase [LDH]) before and after orchiectomy and before chemotherapy for those with extragonadal nonseminomas. They also recommended measuring AFP and hCG shortly before retroperitoneal lymph node dissection and at the start of each chemotherapy cycle for nonseminoma, and periodically to monitor for relapse. The Panel recommended measuring postorchiectomy hCG and LDH for patients with seminoma and preorchiectomy elevations. They recommended against using markers to guide or monitor treatment for seminoma or to detect relapse in those treated for stage I. However, they recommended measuring hCG and AFP to monitor for relapse in patients treated for advanced seminoma.

Sonography of the scrotum

Ultrasonography (US) with a high-frequency (7.5-10-MHz) transducer has become the imaging modality of choice for examination of the scrotum. US examination can provide information valuable for the differential diagnosis of a variety of disease processes involving the scrotum that have similar clinical manifestations (eg, pain, swelling, or presence of mass). The pathologic condition that may be at the origin of such symptoms can vary from testicular torsion to infection to malignancy. The ability of color and power Doppler US to demonstrate testicular perfusion aids in reaching a specific diagnosis in patients with acute scrotal pain. This review covers the anatomy of the scrotum and the scanning protocol for scrotal US, as well as detailed descriptions of disease processes and their US appearances. Newly described conditions such as intratesticular varicoceles and other benign intratesticular cystic lesions are also discussed.

Fluorodeoxyglucose positron emission tomography in the evaluation of germ cell tumours at relapse

Differentiation of active disease from fibrosis/mature teratoma in patients with residual masses or identifying of sites of recurrence in patients with raised markers following treatment of their testicular cancer remains a problem.(18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) has the potential to identify active disease and thereby influence further management in these patients. We performed a retrospective study of the use of FDG-PET in detecting residual/recurrent testicular carcinoma in 55 patients (seventy FDG-PET scans). Forty-seven scans were for the assessment of residual masses (18 had raised markers) and 23 scans were for the investigation of raised markers in the presence of normal CT scans. True positive results were based on positive histology or clinical follow-up. FDG-PET had a positive predictive value (PPV) of 96% and a negative predictive value (NPV) of 90% in patients with residual masses. This PPV was equivalent to that of markers (94%) but FDG-PET had the advantage of identifying the site of that recurrence. The NPV was higher than that of markers. In patients with raised markers alone the PPV of FDG-PET was 92% but the NPV was only 50%. However, subsequent FDG-PET imaging was frequently the first imaging modality to identify the site of disease. FDG-PET effected a management change in 57% of cases. FDG-PET scanning detected viable tumour in residual masses and identified sites of disease in suspected recurrence.

Immunoassay of human chorionic gonadotropin, its free subunits, and metabolites

Multiple hCG-related molecules are present in pregnancy serum and urine samples. These include nonnicked hCG (the hormone), nicked hCG, hyper- and hypoglycosylated hCG, hCG missing the C-terminal extension, free α-subunit, large free α-subunit, free β-subunit, nicked free β-subunit, and β-core fragment. Over 100 immunoassays are sold for quantifying hCG-related molecules in serum or urine. Each measures nonnicked hCG and one of seven combinations of the other hCG-related molecules. This is the source of interassay discordance in hCG determinations. Whereas minor variations are noted in different kit results in normal pregnancy samples (more than twofold variation), much larger variations may be found in two immunoassay results in irregular gestations (spontaneous abortion, aneuploidy, preeclampsia, cancers, and trophoblast disease). Care is needed in choosing an immunoassay. What the assay measures may be more important than its cost or speed. This article reviews the structure of hCG and related molecules. It examines the stability and degradation of hCG, and recognition of hCG-related molecules by different types of immunoassay. Also reviewed are new assays for specifically detecting these other hCG-related molecules.

Monocyte activation in patients with non-seminomatous germ cell tumour of the testis before and after tumour eradication

AIMS

To investigate the kinetics of normalisation of monocyte oxidative activity following tumour eradication.

METHODS

Whole blood lucigenin enhanced chemiluminescence was studied in patients with non-seminomatous germ cell tumours. Group 1 comprised 14 patients who had been "cured" of their cancer (the term "cured" as used in this report denotes a relapse free period of at least three years). Group 2 comprised 15 patients who were followed from diagnosis to up to two years after the start of treatment.

RESULTS

Lucigenin enhanced chemiluminescence of whole blood in the "cured" patients was similar to that of controls and lower than that in patients who had not yet received chemotherapy (group 2). After treatment, chemiluminescence decreased slowly and did not normalise until 18 months after the start of treatment. Tumour necrosis factor alpha (TNF alpha) concentrations were normal in "cured" patients but were raised in those who had not yet received treatment. TNF alpha was normalised 12 months after start of treatment. Alpha-fetoprotein concentrations were raised in most patients but normalised rapidly after tumour eradication.

CONCLUSIONS

The activity of blood monocytes, as measured by whole blood lucigenin enhanced chemiluminescence, is increased in cancer. This activity may be a consequence of the presence of tumour cells. Immunocompetent cells remain active for over a year after eradication of the tumour.

Testicular neoplasms and tumoral markers

The use of tumoral markers and especially of BHCG and AFP in the diagnosis, staging and follow-up of patients affected by testicle germinai neoplasms is now widespread. Nevertheless, controversies stili exist in each one of these fields. Especially for clinical staging, high percentages of understaging of stage I tumours are reported in literature with considerable effects on therapeutical indications and prognosis. The Authors attempt a criticai review on the use of markers for diagnosis and staging of testicular neoplasms based upon their own experience of 79 cases over a 14-year period.