Biological markers in urologic cancer

Perioperative Serum MicroRNA 371a-3p and 372-3p Levels in Patients with Clinically Localized Testicular Masses

Background

MicroRNAs (miRNAs) show promise as blood-based tumor markers for germ cell tumors (GCTs), with miRNA-371-3p being the most studied. The marginal benefit of including other candidate miRNAs to aid with the management of testicular GCTs remains unclear.

Objective

To assess the performance of our combined miRNA assay (371a-3p and 372-3p) in patients with clinically localized testicular masses.

Design setting and participants

This was a retrospective review of patients prospectively enrolled in an ongoing protocol collecting serum miR-371a-3p and miR-372-3p levels (together, Memorial Sloan Kettering Cancer Center [MSK] miRNA assay [MMA]) in patients with a suspected or diagnosed testicular GCT.

Outcome measurements and statistical analysis

The coprimary outcomes of interest were sensitivity and specificity of miR-371a-3p and 372-3p, individually and together, to detect nonteratomatous GCTs in the orchiectomy specimen. Secondary outcomes included additional assay diagnostic parameters, the relationship of patient and disease factors with variations in miRNA levels, and temporal patterns of miRNA normalization after orchiectomy.

Results and limitations

Sixty-two patients were included, 52 had a viable GCT at orchiectomy, and ten had no cancer or a non-GCT. Forty-six patients with a GCT had positive preorchiectomy MMA (sensitivity 88.5% [95% confidence interval {CI}: 79.8, 97.2]), and one patient had positive preorchiectomy MMA but no GCT (specificity 90.0% [95% CI: 71.4, 100]). The diagnostic performance of miR-371a-3-p and miR-372-3p was similar. The time for miRNA to decrease to undetectable levels varied, with some patients having positive levels up to 3 wk after orchiectomy.

Conclusions

The biomarkers miR-371a-3p and miR-372-3p demonstrated high sensitivity and specificity for localized testicular GCTs, but causes of variation in relative miRNA levels and time to normalization for individual patients remain unclear.

Patient summary

We studied the ability of the blood-based biomarkers miR-371a-3p and miR-372-3p to detect testicular cancer (germ cell tumors) in patients with small testicular masses. We found that together and individually these were sensitive and specific for testicular cancer.

MicroRNAs in Testicular Germ Cell Tumors: The Teratoma Challenge

Testicular germ cell tumors (TGCTs) are relatively common in young men, making accurate diagnosis and prognosis assessment essential. MicroRNAs (miRNAs), including microRNA-371a-3p (miR-371a-3p), have shown promise as biomarkers for TGCTs. This review discusses the recent advancements in the use of miRNA biomarkers in TGCTs, with a focus on the challenges surrounding the noninvasive detection of teratomas. Circulating miR-371a-3p, which is expressed in undifferentiated TGCTs but not in teratomas, is a promising biomarker for TGCTs. Its detection in serum, plasma, and, potentially, cystic fluid could be useful for TGCT diagnosis, surveillance, and monitoring of therapeutic response. Other miRNAs, such as miR-375-3p and miR-375-5p, have been investigated to differentiate between TGCT subtypes (teratoma, necrosis/fibrosis, and viable tumors), which can aid in treatment decisions. However, a reliable marker for teratoma has yet to be identified. The clinical applications of miRNA biomarkers could spare patients from unnecessary surgeries and allow for more personalized therapeutic approaches. Particularly in patients with residual masses larger than 1 cm following chemotherapy, it is critical to differentiate between viable tumors, teratomas, and necrosis/fibrosis. Teratomas, which mimic somatic tissues, present a challenge in differentiation and require a comprehensive diagnostic approach. The combination of miR-371 and miR-375 shows potential in enhancing diagnostic precision, aiding in distinguishing between teratomas, viable tumors, and necrosis. The implementation of miRNA biomarkers in TGCT care could improve patient outcomes, reduce overtreatment, and facilitate personalized therapeutic strategies. However, a reliable marker for teratoma is still lacking. Future research should focus on the clinical validation and standardization of these biomarkers to fully realize their potential.

Analysis of a mouse germ cell tumor model establishes pluripotency-associated miRNAs as conserved serum biomarkers for germ cell cancer detection

Malignant testicular germ cells tumors (TGCTs) are the most common solid cancers in young men. Current TGCT diagnostics include conventional serum protein markers, but these lack the sensitivity and specificity to serve as accurate markers across all TGCT subtypes. MicroRNAs (miRNAs) are small non-coding regulatory RNAs and informative biomarkers for several diseases. In humans, miRNAs of the miR-371-373 cluster are detectable in the serum of patients with malignant TGCTs and outperform existing serum protein markers for both initial diagnosis and subsequent disease monitoring. We previously developed a genetically engineered mouse model featuring malignant mixed TGCTs consisting of pluripotent embryonal carcinoma (EC) and differentiated teratoma that, like the corresponding human malignancies, originate in utero and are highly chemosensitive. Here, we report that miRNAs in the mouse miR-290-295 cluster, homologs of the human miR-371-373 cluster, were detectable in serum from mice with malignant TGCTs but not from tumor-free control mice or mice with benign teratomas. miR-291-293 were expressed and secreted specifically by pluripotent EC cells, and expression was lost following differentiation induced by the drug thioridazine. Notably, miR-291-293 levels were significantly higher in the serum of pregnant dams carrying tumor-bearing fetuses compared to that of control dams. These findings reveal that expression of the miR-290-295 and miR-371-373 clusters in mice and humans, respectively, is a conserved feature of malignant TGCTs, further validating the mouse model as representative of the human disease. These data also highlight the potential of serum miR-371-373 assays to improve patient outcomes through early TGCT detection, possibly even prenatally.

MicroRNA-371a-3p-The Novel Serum Biomarker in Testicular Germ Cell Tumors

INTRODUCTION

Testicular germ cell tumors (TGCTs) are a paradigm for the use of serum tumor markers in clinical management. However, conventional markers such as alpha-fetoprotein (AFP), beta-human chorionic gonadotropin (hCG), and lactate dehydrogenase (LDH) have quite limited sensitivities and specificities. Within the last decade, the microRNA-371a-3p (miR371) emerged as a possible new biomarker with promising features.

AREAS COVERED

This review covers the typical features as well as possible clinical applications of miR371 in TGCT patients, such as initial diagnosis, therapy monitoring, and follow-up. Additionally, technical issues are discussed.

EXPERT OPINION

With a sensitivity of around 90% and specificity >90%, miR371 clearly outperforms the classical serum tumor markers in TGCTs. The unique features of the test involve the potential of modifying recent standards of care in TGCT. In particular, miR371 is expected to aid clinical decision-making in scenarios such as discriminating small testicular TGCT masses from benign ones prior to surgery, assessing equivocal lymphadenopathies, and monitoring chemotherapy results. Likewise, it is expected to make follow-up easier by reducing the intensity of examinations and by sparing imaging procedures. Overall, the data presently available are promising, but further prospective studies are required before the test can be implemented in standard clinical care.

Circulating MicroRNAs, the Next-Generation Serum Biomarkers in Testicular Germ Cell Tumours: A Systematic Review

CONTEXT

Clinical management of testicular germ cell tumours (GCTs) is hampered by low sensitivity and specificity of the biomarkers currently in use. Circulating microRNAs (miRs) might offer the potential to address areas of unmet clinical need.

OBJECTIVE

To systematically evaluate the evidence for clinical applications of serum levels of miR302/367 and miR371-3 in adult testicular GCTs in terms of primary diagnosis, various clinical scenarios, and the costs of clinical implementation.

EVIDENCE ACQUISITION

We performed a critical review of PubMed/Medline, Embase and the Cochrane Library in January 2021 in accordance with Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement.

EVIDENCE SYNTHESIS

Thirty-one manuscripts addressed miR performance and potential clinical use in testicular GCT. Of these, 23 evaluated the utility in primary diagnosis, seven in early-stage disease, and 13 in metastatic disease, and two addressed the costs of clinical implementation. Of the various miRs studied, miR-371a-3p appears the most useful and potentially the only one that needs to be assayed, with an area under the receiver operating characteristic curve >0.90, sensitivity of 89-96%, and specificity of >90% for both seminoma and nonseminoma, surpassing the classic serum tumour markers. The miRs studied to date are not elevated in cases with teratoma only. Levels of miR-371a-3p correlate with primary tumour mass, clinical stage, and International Germ Cell Cancer Collaborative Group risk groups. Serial measurements mirror treatment efficacy in all clinical stages.

CONCLUSIONS

Circulating miRNA levels, particularly of miR-371a-3p, have potential for incorporation in clinical practice and may aid in clinical decision-making in various clinical scenarios in GCT.

PATIENT SUMMARY

We analysed the current evidence on the usefulness of blood levels of molecules called microRNAs in the management of testicular tumours. The microRNA-371a-3p molecule has better sensitivity and specificity than the markers currently being measured. This new biomarker may soon have a place in clinical practice.

Graded expression of microRNA-371a-3p in tumor tissues, contralateral testes, and in serum of patients with testicular germ cell tumor

Background: Serum levels of microRNA-371a-3p represent a specific tumor marker of testicular germ cell tumors (GCTs) but the origin of circulating miR-371a-3p is not finally resolved. The correlation between miR-levels in tissue and serum is unclear.

Results: MiR-levels in GCT tissue are 399-fold higher than in contralateral testicular tissue and 5843-fold higher than in non-testicular tissue. MiR tissue levels correlate with corresponding serum levels (r² = 0.181). ISH detected miR-371a-3p intracellularly in GCT cells except teratoma. A low expression was also detected in normal testicular germ cells.

Conclusions: Circulating miR-371a-3p is specifically derived from GCT tissue. The miR is present in GCT cells except teratoma. A low expression is also found in normal testicular tissue but not in non-testicular tissue. MiR-371a-3p levels in tissue and serum correlate significantly. This study underscores the usefulness of serum miR-371a-3p as tumor marker of GCT.

Patients and methods: Expression levels of miR-371a-3p were concurrently measured in tissues of GCT, contralateral testes (n = 38), and in serum (n = 36) with real time PCR. For control, 5 healthy testicles and 4 non-testicular tissue samples were examined. MiR-levels were compared using descriptive statistical methods. We also performed in situ hybridization (ISH) of GCT tissue with a probe specific for miR-371a-3p.

Serum Levels of MicroRNA-371a-3p (M371 Test) as a New Biomarker of Testicular Germ Cell Tumors: Results of a Prospective Multicentric Study

PURPOSE

Previous studies suggested that serum levels of microRNA (miR)-371a-3p (so-called M371 test) have a much higher sensitivity and specificity than the classic markers of testicular germ cell tumors (GCTs) and are applicable toward both seminoma and nonseminoma. We sought to confirm the usefulness of this test as a novel biomarker for GCT.

PATIENTS AND METHODS

In a prospective, multicentric study, serum samples of 616 patients with testicular GCTs and 258 male controls were examined for serum levels of miRNA-371a-3p (miR levels) by quantitative polymerase chain reaction. The GCT population encompassed 359 patients with seminoma and 257 with nonseminoma; 371 had clinical stage I disease, 201 had systemic disease, and 46 had relapses. Paired measurements before and after orchiectomy were performed in 424 patients; 118 with systemic disease had serial measurements during treatment. miR levels were compared with those of β-human chorionic gonadotropin, α-fetoprotein, and lactate dehydrogenase.

RESULTS

For the primary diagnosis of GCT, the M371 test showed a sensitivity of 90.1%, a specificity of 94.0%, an area under the curve of 0.966 upon receiver operating characteristic analysis, and a positive predictive value of 97.2%. α-Fetoprotein, β-human chorionic gonadotropin, and lactate dehydrogenase had sensitivities of less than 50% in seminoma and slightly higher sensitivities in nonseminomas. miR levels were significantly associated with clinical stage, primary tumor size, and response to treatment. Relapses had elevated miR levels that subsequently dropped to normal upon remission. Teratoma did not express miR-371a-3p.

CONCLUSION

The M371 test outperforms the classic markers of GCT with both a sensitivity and a specificity greater than 90%. All histologic subgroups, except teratoma, express this marker. The test could be considered for clinical implementation after further validation.

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.

The Novel Biomarker of Germ Cell Tumours, Micro-RNA-371a-3p, Has a Very Rapid Decay in Patients with Clinical Stage 1

BACKGROUND

Accumulating evidence suggests serum levels of microRNA (miR)-371a-3p to be a novel tumour marker of testicular germ cell tumours (GCTs). Presently, there is only limited information regarding the velocity of decline of serum levels in response to treatment.

PATIENTS AND METHODS

Twenty-four patients with testicular GCT (20 seminoma, 4 nonseminoma, median age 40 years) with clinical stage 1 had measurements of serum levels of miR-371a-3p preoperatively and repeatedly on the following 3 days. Three had additional tests done within 24 h after surgery. Measurement results were analysed using descriptive statistical methods.

RESULTS

Serum levels dropped to 2.62, 1.27, and 0.47% of the preoperative level within 1, 2, and 3 days, respectively. The computed half-life amounts to 3.7-7 h. The velocity of decay is significantly associated with tumour size.

CONCLUSIONS

Serum-levels of miR-371a-3p have a short half-life of less than 12 h. The rapid decay after treatment represents a valuable feature confirming the usefulness of miR-371a-3p as a valuable serum biomarker of GCT.

Afp and Hcg in Germ Cell Tumors

The high specificity and sensitivity of testicular tumor markers make them particularly useful in the management of these neoplasms. Basal value represents an independent prognostic variable, influencing the choice of therapy. An increase in marker level before chemotherapy could also acquire a powerful prognostic significance. The decay curve pattern is indicative of the radicality of surgery. Also during chemotherapy the behavior of markers conditions further therapeutic strategies.

Targeting MLL-AF4 with short interfering RNAs inhibits clonogenicity and engraftment of t(4;11)-positive human leukemic cells

The chromosomal translocation t(4;11) marks infant acute lymphoblastic leukemia associated with a particularly dismal prognosis. The leukemogenic role of the corresponding fusion gene MLL-AF4 is not well understood. We show that transient inhibition of MLL-AF4 expression with small interfering RNAs impairs the proliferation and clonogenicity of the t(4; 11)-positive human leukemic cell lines SEM and RS4;11. Reduction of mixed-lineage leukemia (MLL)-ALL-1 fused gene from chromosome 4 (AF4) levels induces apoptosis associated with caspase-3 activation and diminished BCL-X(L) expression. Suppression of MLL-AF4 is paralleled by a decreased expression of the homeotic genes HOXA7, HOXA9, and MEIS1. MLL-AF4 depletion inhibits expression of the stem-cell marker CD133, indicating hematopoietic differentiation. Transfection of leukemic cells with MLL-AF4 siRNAs reduces leukemia-associated morbidity and mortality in SCID mice that received a xenotransplant, suggesting that MLL-AF4 depletion negatively affects leukemia-initiating cells. Our findings demonstrate that MLL-AF4 is important for leukemic clonogenicity and engraftment of this highly aggressive leukemia. Targeted inhibition of MLL-AF4 fusion gene expression may lead to an effective and highly specific treatment of this therapy-resistant leukemia.

Prognostic significance of marker half-life during chemotherapy in non-seminomatous germ cell testicular tumors

Decrease in serum alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) levels is considered as a response during chemotherapy of non-seminomatous germ cell testicular tumors, but data on the prognostic significance of marker half-life remains inconclusive. Serum marker half-life was evaluated in 34 patients with elevated markers, receiving chemotherapy (CT). Marker half-life was calculated from the natural logarithm of the sequential AFP or HCG concentrations. The correlation between event-free (EFS) and overall survival (OS) with unfavorable half-lives of AFP and HCG was evaluated. Median actual half-life (AHL) AFP was 3.9 days (range, 1.4-21.5) and median AHL HCG was 4.4 days (range, 1.4-21.0); 82% of the patients had a satisfactory initial decline in AFP, and 71% had a satisfactory initial decline in HCG. There was a significant difference in EFS and OS between the two groups of patients with an AFP half-life < 7 days and > 7 days. HCG half-life did not adversely affect EFS and OS. The correlation of better EFS and OS with appropriate AFP marker half-life during chemotherapy could provide a dynamic method, which could complement the standard baseline prognostic factors, for the prediction of prognosis.

Benign and malignant prostatic neoplasms: human studies

Because the present ability to treat and cure patients with prostate cancer is limited to those patients with pathologically organ-confined disease, it has become increasingly important to diagnose this disease at an early stage, when cure is most likely. Recent advances in imaging may allow the urologist and the pathologist to make the diagnosis of prostate cancer much earlier in the natural course of the disease. It therefore becomes imperative to have methods available to predict which patients have a high probability of progressing so that treatment can be assigned logically and appropriately. Our current methods of prognosis determination (stage and grade) do not allow accurate assessment of tumor behavior in the majority of individual patients with prostate cancer. Therefore, more accurate quantification of nuclear and cellular changes that take place as a tumor progresses to take on the aggressive (metastatic) phenotype are urgently needed. Experimental techniques have proven useful in answering these questions and now seem ready for large-scale testing in clinical studies.

Use of markers in the diagnosis and follow-up of metastases

— Tumor markers are antigens which can be associated with certain malignancies. A variety of markers have been proposed for genitourinary tumors. The best known examples are human chorionic gonadotropin (bHCG) and alpha-fetoprotein (AFP) for testicular tumors, prostatic acid phosphatase (PAP) and prostatic specific antigen (PSA) for prostatic cancer. The plasma levels of these substances are influenced by the tumor mass and therefore by the tumor stage. Plasma levels can be markedly high when metastases are present, though a few patients without metastases may elaborate an abnormal amount of markers. The removal of the primary tumor leads to a fall to normal levels: a continuing high level indicates residual primary tumor or the presence of metastases. Measurements of markers are also of value in estimating the effects of medical treatment and in detecting local or distant recurrences.

The human repertoire of antibody specificities against Thomsen-Friedenreich and Tn-carcinoma-associated antigens as defined by human monoclonal antibodies

Human monoclonal antibodies specific for tumour-associated Thomsen-Friedenreich (TF) [Gal(beta 1-3)GalNAc(alpha)-O-] and Tn [GalNAc(alpha)-O-] glycoproteins were prepared using peripheral blood lymphocytes from healthy blood donors. The B lymphocytes were either directly transformed with Epstein-Barr virus (EBV) or transformed after an in vitro stimulation period with synthetic glycoproteins. The EBV-transformed lymphocytes were subsequently fused with a mouse-human heteromyeloma to secure antibody production and stability. IgM antibodies exhibiting different patterns of specificity for synthetic TF and Tn antigens were obtained, including antibodies specific for the alpha and beta forms of different Gal(beta 1-3)GalNAc-O- and GalNAc-O- conjugates and antibodies agglutinating neuraminidase-treated erythrocytes. Several of the human monoclonal antibodies showed an increased binding to cultured carcinoma cells as compared to melanoma cells. This straightforward approach for the production of human monoclonal antibodies demonstrates the possibility of investigating the reactivity pattern of tumour-binding antibodies from peripheral blood lymphocytes. The binding patterns of these monoclonal antibodies show that healthy donors carry different fine specificities against synthetic TF/Tn antigens and that these antibodies react with different tumour cells.

Enolase isozymes in seminoma

We determined concentrations of alpha and gamma-enolases in normal testis and in seminoma tissues by enzyme immunoassay. Concentrations of alpha-enolase were 4,170 +/- 2,040 ng/mg protein in normal testis (n = 8) and 8,140 +/- 4,480 ng/mg protein in seminoma (n = 8). Concentrations of gamma-enolase in seminoma (460 +/- 571 ng/mg protein) were significantly higher than those of normal testis (59 +/- 15 ng/mg protein). Immunohistochemistry showed positive tumor cells for gamma-enolase in 6 of 8 seminoma cases (75%). Serum gamma-enolase levels were elevated (greater than 6.0 ng/ml) in 9 of 12 patients (75%) with seminoma: 60% of stage I, and 100% of stages II and III. In 10 patients treated by surgical excision and chemotherapy, serum gamma-enolase was significantly reduced after the treatment. These findings indicate that elevated serum gamma-enolase is derived from enhanced gamma-enolase in seminoma tissues, and that serum gamma-enolase could be a useful biomarker for staging and monitoring clinical course in patients with seminoma.

Combination of blood group ABH antigen status and DNA ploidy as independent prognostic factor in transitional cell carcinoma of the urinary bladder

The prognostic value of DNA ploidy and blood group (ABH) antigen reactivity was studied in a consecutive retrospective study of 230 patients with primary transitional cell carcinoma of the urinary bladder. In 195 cases the DNA ploidy and ABH reactivity could be assessed in paraffin-embedded tissue. Early progression (in the first 3 years) occurred in 2% of the patients with diploid ABH positive tumours and in 31% of those with aneuploid ABH negative tumours. The 5-year survival rates corrected for intercurrent mortality were 95 and 56% respectively. In a Cox multivariate analysis, T category, age at diagnosis and histological grade emerged as significant independent prognostic indicators of bladder cancer death, whereas ABH reactivity and DNA ploidy had no significant independent value. However, if the combination of ABH reactivity and DNA ploidy was included in the Cox model, this and T category were independent predictors. When this Cox model was applied to assess the risk of progression, the only independent prognostic factor was the combination of ABH reactivity and DNA ploidy.

Differential hypomethylation of the c-myc protooncogene in bladder cancers at different stages and grades

The 5-methylcytosine content of c-myc proto-oncogene DNA obtained from samples of normal bladders and of bladders with transitional cell carcinoma of different stage and grade was analyzed. Five CCGG sites (from the third coding region to the 3' flanking region of the gene) which showed different methylation in normal and neoplastic samples were identified. The overall c-myc methylation levels were significantly reduced in carcinomas. Furthermore, a significant correlation between disease invasiveness and methylation level was found. Nevertheless, in each group of patients with the same histological grade, heterogeneity has been observed. This might be suggestive of different prognosis of the disease.

Serum lactate dehydrogenase and human choriogonadotrophin in seminoma

The clinical significance of serum lactate dehydrogenase (LDH) and serum human choriogonadotrophin (HCG) as tumour markers was assessed in 105 patients with pure seminoma from whom 981 blood samples were analysed. The specificity of elevated HCG and LDH was 100 and 93% respectively. The comparable sensitivity was 32 and 47%. Serum LDH could not discriminate between patients with clinical stage I seminoma, prior to orchiectomy, and those with benign testicular lesions. In patients with advanced metastatic seminoma subjected to orchiectomy, serum LDH was increased in 82%, but elevated HCG was found in only 40%. After cisplatin-based chemotherapy, falsely elevated LDH was observed in 7 of 37 tumour-free patients, but HCG was normal in all patients with no evidence of disease. Six patients with residual tumour after chemotherapy had normal LDH and 4 of them had elevated HCG; 70% of the relapses in seminoma patients were associated with increased LDH (64%) and/or HCG (48%). In seminoma patients with comparable disease extension, elevated HCG seemed to be correlated with a high risk of relapse. Patients with normal pre-treatment LDH had a lower relapse-free survival rate than patients with elevated LDH. HCG is a highly specific tumour marker in seminoma with a rather low sensitivity. HCG is particularly useful for the primary diagnosis in patients with testicular lesions and during monitoring of chemotherapy in seminoma patients. LDH is less specific than HCG. Both markers should be analysed during follow-up of seminoma patients, since 70% of relapses are associated with an increase in one or both markers. Elevated pre-treatment HCG, but not elevated LDH, seems to indicate an increased risk of relapse in patients with seminoma.

Prostatic specific antigen and prostatic acid phosphatase in the monitoring and staging of patients with prostatic cancer

Serum prostatic specific antigen and prostatic acid phosphatase levels were measured retrospectively and evaluated in 357 men with benign prostatic hypertrophy and in 209 men with various stages of prostatic carcinoma. Although prostatic specific antigen values were elevated in 21 per cent of the patients with benign prostatic hypertrophy, the elevations usually were low and did not interfere with clinical interpretation. Prostatic specific antigen was elevated in 98 per cent of 86 men with active stage D2 disease; in 22 per cent of the men prostatic specific antigen was the only elevated marker. In contrast, prostatic acid phosphatase was the only elevated marker in 1 per cent of the patients with stage D2 disease and neither marker was elevated in 2 per cent. Among 74 patients in whom prostatic specific antigen and prostatic acid phosphatase determinations were made before radical prostatectomy, prostatic specific antigen was elevated substantially (greater than 10 ng. per ml.) in 59 per cent (26 of 44) with extracapsular disease and in only 7 per cent (2 of 30) without extracapsular disease. More importantly, of those 28 patients with substantially elevated prostatic specific antigen levels 26 (93 per cent) had extracapsular disease. Serial serum measurements showed that prostatic specific antigen either reflected or predicted clinical status in more than 97 per cent of the patients. We conclude that prostatic specific antigen is an excellent serum tumor marker for monitoring patients with prostatic carcinoma and that it surpasses prostatic acid phosphatase in this regard. Prostatic specific antigen also may be useful in staging prostatic carcinoma and it may change our attitudes significantly about the therapeutic responses to this cancer.