Monoclonal antibody assay of serum placental alkaline phosphatase in the monitoring of testicular tumours

A monoclonal antibody (H17E2) recognising both placental alkaline phosphatase (PLAP) and testicular PLAP-like alkaline phosphatase was incorporated in a solid phase immunoassay. This was used to measure levels of PLAP in 257 sera from 148 patients with germ cell neoplasms of the testis. High levels of PLAP were found in all patients with active seminomas (mean 0.85 O.D.) compared to those in clinical remission (mean 0.20 O.D.) (P less than 0.0001). More importantly, changing levels of PLAP correlated with the course of disease in 79 samples from 33 patients with seminoma (P less than 0.0001). Elevated PLAP levels were also noted in patients in remission who were smokers (mean 0.32 O.D.) compared to non-smokers (mean 0.15 O.D.) (P less than 0.001). These data demonstrate that determination of PLAP levels using this sensitive immunoassay is an important new adjunct in the monitoring of the response to treatment in patients with seminoma.     

Placental alkaline phosphatase as a tumour marker in seminoma using the H17 E2 monoclonal antibody assay

Serum samples from 62 patients with seminoma were assayed for placental alkaline phosphatase-like activity using the monoclonal antibody H17 E2, in order to evaluate its utility as a serum tumour marker. Fifteen of 16 patients (94%) with active seminoma had elevated serum PLAP levels. Sixteen of 46 (35%) of patients considered to be in remission had elevated PLAP levels (false positive rate 35%). Fifteen false positive results were considered attributable to concomitant smoking, and if these patients are excluded, only one false positive case was detected. In 7 out of 7 patients sequential PLAP assays reflected clinical response to treatment.     

Clues from natural history and results of treatment supporting the monoclonal origin of germ cell tumours

Recent observations have suggested that a major factor in the development of germ cell tumours may be excessive mitogenic stimulus developed because of failure of feedback suppression of the normal pituitary drive due to atrophic damage to germinal epithelium. With this observation and the increasing recognition that there is a common in situ stage which precedes both seminoma and malignant teratoma/non-seminoma there has been a polarisation of views regarding the relationship between seminoma and malignant teratoma/non-seminoma, with some authors viewing these two entities as separate unrelated transformational events while others hypothesise that seminoma is an interim stage of clonal evolution associated with increased malignant potential towards malignant teratoma/non-seminoma. This chapter reviews the clinical evidence supporting the concept of clonal evolution which arises from the observation that the modal DNA content of seminoma (3.6N) is intermediate between that of in situ carcinoma (4.2N) and malignant teratoma/non-seminoma (2.8N). These observations, taken with the observation that the median age of patients with mixed tumours containing both seminoma and non-seminoma elements (30 years) is intermediate between the slower growing seminoma (35 years) and faster growing malignant teratoma/non-seminoma (25 years), as well as studies of spontaneous regression, tumours in AIDS patients chemo/radio sensitivity and post mortem histology, provide the most convincing evidence supporting clonal evolution. However, these observations cannot explain the fact that some patients have more than one focus of tumour (which can be of different histological type) in a single testis with normal tubules in between, even if they have in situ carcinoma. An extreme manifestation is seen in patients who are treated and cured from metastases arising from one testicle who then die from metastases from a completely different histological type arising from a second transformation event of a germ cell in the contralateral testis. The conclusion from these observations is that it is indeed possible for polyclonal development of tumours to occur, as is seen for bladder and bowel tumours, but they do not detract from the concept that seminoma is an intermediate event in the evolution from in situ carcinoma to malignant teratoma/non-seminoma.     

Glutathione S-transferase expression in the human testis and testicular germ cell neoplasia.

Glutathione S-transferase (GST) isoenzyme expression is altered in a variety of neoplasms and the enzymes are implicated in metabolism of carcinogens and resistance to drugs, including cisplatin. We have studied GST Alpha, Pi, Mu and microsomal isoenzyme expression by immunohistochemistry in normal and cryptorchid testes, intratubal germ cell neoplasia (ITGCN), seminoma and non-seminomatous germ cell tumours. In 16 stage II-IV malignant teratoma intermediate (MTI) both orchidectomy and post-treatment residual surgical masses were studied. All four isoenzymes were strongly expressed in Leydig and Sertoli cells. GST Pi was absent from normal spermatogonia but strongly expressed by the neoplastic germ cells of ITGCN and seminoma. GST Pi was strongly expressed in all elements of teratoma, irrespective of differentiation. There were no qualitative differences in expression between primary and post-chemotherapy metastases. GST Alpha expression in teratoma correlated with epithelial differentiation. GSTs may be important in normal spermatogenesis and protection of germ cells from teratogens and carcinogens. They may have a role in testicular tumour drug resistance but this role is not well defined. GST Pi is a new marker for ITGCN.     

An analysis of surveillance for stage I combined teratoma--seminoma of the testis.

We analysed 973 patients with stage I testicular tumours presenting between 1983 and 1994. The median ages at presentation for non-seminomatous germ cell tumour (teratoma) were 27 years, seminoma 36 years and combined tumour 33 years. These differences were statistically significant (Mann-Whitney P < 0.05), suggesting that combined tumours may have a separate natural history. We, therefore, analysed all stage I patients managed with surveillance (530 in total) post orchidectomy. The actuarial 5 year relapse-free survival and anatomical patterns of relapse were identical for non-seminomatous germ cell tumour (NSGCT) and combined tumour and both were statistically distinct from seminoma (P = 0.01, log-rank test, chi-square test P = 0.001). The association of seminoma within a histologically confirmed NSGCT has no influence on the clinical outcome.     

Primary malignant mediastinal germ cell tumours: improved prognosis with platinum-based chemotherapy and surgery.

A retrospective analysis was performed of 18 patients with primary malignant germ cell tumours of the mediastinum treated with platinum-based chemotherapy between 1977 and 1990. All seven patients with pure seminoma were treated initially with chemotherapy and four of these patients received additional mediastinal radiotherapy. Only one patient relapsed; his initial therapy had included radiotherapy and single-agent carboplatin and he was successfully salvaged with combination chemotherapy. With a follow-up of 11 to 117 months (median 41 months) all seven patients with seminoma remain alive and disease free giving an overall survival of 100%. Eleven patients had malignant non seminoma; following chemotherapy eight of these had elective surgical resection of residual mediastinal masses. Complete remission was achieved in nine (82%) patients, however, one of these patients died from bleomycin pneumonitis. With a follow-up of 12 to 113 months (median 55 months) eight of 11 (73%) patients with malignant mediastinal teratoma remain alive and disease free.     

Multiple biochemical tumor markers in seminoma. A double-blind study

The value of certain biochemical tumor markers have been well established in nonseminomatous testicular cancer. However, the lack of frequent tumor markers in the sera of patients with seminoma has prompted us to embark on this double blind study. The authors studied 89 patients with the histologic diagnosis of seminoma utilizing placental alkaline phosphatase (PLAP), gamma-glutamyl transpeptidase (gamma GT), human chorionic gonadotropin (hCG), and alpha-fetoprotein (AFP). It was found that 12/30 patients (40%) with active tumor had elevated serum PLAP and 10/30 (33%) of these patients had elevated serum levels of GGT. Eighty percent of the patients with clinically active tumors had detectable serum levels of one or more of these biochemical markers. Since the frequency of the previous tumor markers have been scarce in seminoma, these serial utilization of these biochemical markers should assist the clinician to detect and monitor seminoma patients more efficaciously. However, the false-positive, false-negative, rates, and biologic half lifes of these markers should be taken in account.     

Referral patterns within Scotland to specialist oncology centres for patients with testicular germ cell tumours. The Scottish Radiological Society and the Scottish Standing Committee of the Royal College of Radiologists.

Details of 1123 patients registered in Scotland between 1983 and 1990 for testicular cancer under the Scottish Cancer Registration Scheme were obtained and compared with registrations within the five Scottish oncology centres. Some registration discrepancies were identified. Twenty-eight cancer registrations (2.5%) were coded to the wrong site, 29 patients seen at oncology centres had no cancer registration and 14 cancer registrations had the wrong histology. Five hundred and twenty-seven patients with testicular non-seminomatous germ cell tumours (NSGCT) and 567 with testicular seminoma were identified. Referral rates to specialist oncology centres for testicular germ cell tumours were measured by period and health board area of residence. For the whole study period 92% of NSGCT and 93% of seminoma patients were referred to specialist centres for treatment. Referral rates for different health board areas of residence were not significantly different. This study shows that within Scotland the majority of patients with testicular NSGCT and seminoma are referred to specialist centres, and suggests referral rates of around 92% are underestimates. Access is not related to area of residence.     

The clinical significance of flow cytometric c-myc oncoprotein quantitation in testicular cancer

A sensitive flow cytometric assay has been developed using a monoclonal antibody, Myc 1-6E10, to quantitate c-myc oncoprotein levels in nuclei isolated from wax embedded testicular tumours. The oncoprotein (p62c-myc) level increased significantly with increasing teratoma differentiation. Patients with intermediate and undifferentiated tumours who developed recurrence had lower p62c-myc levels than those who were disease free since their initial treatment. Such quantitative biochemical methods may provide new prognostic indices for cancer patients.     

Surveillance for stage I testicular germ cell tumours: results and cost benefit analysis of management options

Between 1979 and 1996 303 men with stage I testicular germ cell tumours (120 seminoma and 183 non-seminomatous germ cell tumours (NSGCT)) were enrolled onto a programme of surveillance. In our institutions the frequency of computed tomography (CT) scans is reduced compared with other centres. For all 303 men, the median follow-up is 5.1 years (range: 0.1-21.7 years) and there have only been 3 deaths (1 from disease, 1 from neutropenic sepsis and 1 from secondary leukaemia). 52/183 (28%) patients with NSGCT and 18/120 (15%) patients with seminoma have relapsed. The relapse-free survival at 5 years is 82% for seminoma and 69% for NSGCT (Logrank P=0.004). All men who relapsed, except 1 man with NSGCT, were in the International Germ Cell Cancer Collaborative Group good or intermediate prognosis group at relapse. Half of the seminoma relapses presented with symptoms and 31% of the NSGCT relapses. The remaining relapses were detected serologically or radiologically by the surveillance programme. 5 men (2%) on surveillance, 3 with initial diagnosis of seminoma and 2 with NSGCT, have developed second contralateral testis tumours (all stage I seminomas). In a well motivated centre a policy of surveillance for stage I testicular germ cell tumours (both NSGCT and seminoma) is associated with a low mortality rate (3/303, 1%) and may have the advantage of sparing overtreatment with potentially toxic therapies in this group of young men.     

Platinum-based chemotherapy of primary extragonadal germ cell tumours: the Hellenic Cooperative Oncology Group experience.

Extragonadal germ cell tumours (EGCT) are uncommon, most frequently arise in the mediastinum and retroperitoneum and have variable responses to platinum-based chemotherapy. A retrospective analysis was performed on 38 patients with EGCT treated with cisplatin-based (CDDP) or carboplatin-based (CBDCA) chemotherapy between 1984 and 1998. Twenty-four patients had nonseminomatous germ cell tumours (NSGCT) and 14 seminoma. Twenty-two tumours arose in the mediastinum (13 nonseminomas, 9 seminomas) and 16 in the retroperitoneum (11 NSGCT, 5 seminomas). Initial surgery included complete resection in 1 patient, biopsy in 27 patients and debulking surgery in 10 patients. Complete response rates with chemotherapy +/- surgery were as follows: mediastinum 14 of 21 (66.66%) patients (8 of 12-75% NSGCT, 6 of 9-66.66% seminomas) and retroperitoneum 14 of 16 (87.5%) patients (9 of 11-81.81% NSGCT, 5 of 5-100% seminomas). One patient who underwent complete resection of a mediastinal malignant teratoma combined, received PVB chemotherapy on an adjuvant basis and remains alive and disease-free. Three additional seminoma patients who achieved partial response after chemotherapy remain alive and disease-free following mediastinal radiotherapy. All 14 patients with extragonadal seminomas remain alive with no evidence of disease at a median follow-up of 49 months (range 7-164), giving an overall survival of 100%. Nine of 13 (69.23%) patients with mediastinal NSGCT are long-term disease-free at a median follow-up of 43.5 months (range 7-152). Nine of 11 (81.81%) patients with retroperitoneal NSGCT remain alive and disease-free at a median follow-up of 56 months (range 14-110). Complete surgical resection of residual mass was undertaken in 10 patients (3 seminomas, 7 nonseminomas). The histology revealed necrosis/fibrosis in 6 patients (3 seminomas, 3 NSGCT) and viable cancer in 4 patients. Patients who had viable malignant cells in the resected specimens received two more courses of VelP chemotherapy. None of our patients had relapsed at the time of this analysis. None of our 6 patients who underwent testicular biopsy (1 patient) or orchiectomy (5 patients) due to suspicious ultrasound of the testis were found to have testicular tumour or fibrotic scar. In conclusion, this retrospective analysis showed significant responses in patients with either mediastinal or retroperitoneal NSGCT treated with CDDP- or CBDCA-based chemotherapy +/- surgery. All patients with extragonadal seminomas remain alive with no evidence of disease, regardless of the site at presentation.     

An immunohistological study of testicular germ cell tumours using two different monoclonal antibodies against placental alkaline phosphatase.

Using two monoclonal antibodies directed against placental alkaline phosphatase (H17E2 and D20L) the immunohistological staining of testicular germ cell tumours was compared with that of a wide range of normal and malignant tissues. All seminomas and malignant teratomas tested gave strong positive labelling with H17E2 but were either negative or only patchily positive with D20L. Neither antibody gave any positive reaction on the normal tissues tested. All other malignancies were negative with both antibodies apart from two cases of ovarian and one case of endometrical cancer (strongly stained by H17E2) and three cases of colonic carcinoma (weakly and patchily stained by both H17E2 and D20L). This indicates that germ cell neoplasms generally express a form of placental alkaline phosphatase recognised by antibody H17E2.     

Placental alkaline phosphatase, alphafetoprotein and carcinoembryonic antigen in testicular tumors. Tissue typing by means of cytologic smears.

Indirect immunofluorescence and radioimmunoassay with specific rabbit antisera demonstrated the occurrence of alphafetoprotein (AFP), carcinoembryonic antigen (CEA) and placental alkaline phosphatase (PLAP) in primary testicular tumor cells. Embryonal carcinomas had AFP- and CEA-containing cells, sometimes PLAP. PLAP and sometimes CEA were found in seminoma cells. Sera from patients with advanced non-seminomatous tumors could contain any of these antigens or any combination of them. Sera from patients with seminomas had raised PLAP or CEA. PLAP appears to be a new marker for seminoma.     

Identification of testicular atypical germ cells by an immunohistochemical technique for placental alkaline phosphatase

The identification of atypical testicular germ cells is often difficult by by routine histologic examination. By immunohistochemical detection of placental alkaline phosphatase (PLAP) and by periodic acid Schiff staining of glycogen, atypical germ cells were easily identified in testicular samples. Forty-one fetal and adult testes were used for a preliminary study, and 121 testes from infants and adults with either cryptorchidism or germ cell tumors were studied for the presence of atypical germ cells. Two types of clear germ cells were differentiated histochemically, and one with PLAP-positive cell surfaces and glycogen-rich cytoplasm was considered to be atypical. The alkaline phosphatase of atypical germ cells appeared to be similar to that found in a few germ cells of early fetal testes. The atypical germ cells seemed to be multi-potential malignant cells capable of developing not only into seminoma but also into other germ cell tumors. Only in yolk sac tumor of infants were the atypical germ cells absent from tumor-adjacent seminiferous tubules.     

DNA topoisomerase I and II expression in drug resistant germ cell tumours

A small number of testicular germ cell tumours are refractory to current chemotherapy regimens. DNA topoisomerase I is the target for several new drugs and a potential candidate treatment for chemorefractory germ cell tumours. DNA topoisomerase II alpha is the target for etoposide, which is currently used regularly in germ cell tumour treatment. The expression of DNA topoisomerase I and II alpha were therefore assessed immunohistochemically in a range of testicular tumours, especially those with persistent malignant elements on retroperitoneal lymph node dissection. Pre-chemotherapy orchidectomy specimens were matched with post-chemotherapy retroperitoneal lymph node dissections to examine changes in expression. There was considerable variation in the expression of topoisomerase I in different tumour types. Both yolk sac tumours and teratoma, mature showed universal expression of topoisomerase I, while 38% of seminomas and 30% of embryonal carcinomas were positive. Strong topoisomerase II alpha expression was found in embryonal carcinoma. There was a negative correlation between topoisomerase I and II alpha expression (P=0.004) and downregulation of topoisomerase II alpha after chemotherapy (P=0.02). Topoisomerase I expression appears to increase in those cases with residual teratoma, mature, but is largely unchanged in those cases remaining as embryonal carcinoma. These results suggest that topoisomerase I inhibitors may be useful in chemorefractory germ cell tumours, especially yolk sac tumours and where there are unresectable residual teratoma, mature deposits.     

Expression of a specific mouse germ cell nuclear antigen (GCNA1) by early embryonic testicular teratoma cells in 129/Sv-Sl/+ mice

Spontaneous testicular teratomas which develop at a high rate in 129/Sv-Sl/+ mice are thought to be derived from germ cells. The teratomas present initially as groups of atypical germ-like cells within seminiferous cords of the 15.5 days post coitum (dpc) embryonic testes. These pluripotent teratoma stem cells are capable of differentiating into many kinds of tissues in adult mice. In this immunohistochemical study, we have examined the testes of 129/Sv-Sl/+ mice to determine whether the teratoma cells which developed in these gonads retain the nuclear antigen GCNA1. GCNA1 is a 110 kDa mouse Germ Cell Nuclear Antigen recognized by a rat monoclonal antibody 10D9G11. GCNA1 is expressed in mouse germ cells after they migrate into the genital ridge (11.5 dpc), throughout embryonic development until postnatally germ cells arrive at the diplotene/dictyate stage of the first meiotic division, when it is no longer expressed. Early foci (16.5 dpc) of teratoma stem cells in 129/Sv-Sl/+ mice strongly express GCNA1, but down regulate GCNA1 expression by 19.5 dpc. The loss of GCNA1 expression from teratoma stem cells late in embryonic development is in contrast to embryonic gonocytes which retain GCNA1 expression throughout fetal development. All postnatal undifferentiated and differentiated teratoma cells did not appear to express GCNA1. The expression of the germ cell specific nuclear antigen GCNA1 in early teratoma stem cells further demonstrated that the testicular teratomas originate from early germ cells. The stronger reaction of monoclonal antibody 10D9G11 to GCNA1 within early teratoma cells compared to normal germ cells makes GCNA1 useful in identifying early embryonic tumor foci.     

Serum alpha1-foetoprotein levels in 153 male patients with germ cell tumours.

--alpha1-Foetoprotein (AFP) levels have been measured by radioimmunoassay in the serum of 153 male patients with gonadal and extragonadal germ cell tumours. Thirty-five patients with pure seminoma, and 34 patients with teratoma but without any postoperative evidence of residual or recurrent tumour, consistently had normal serum AFP levels (less than 25 ng/ml). Of 84 patients with active teratomas, 56 (67%) had serological evidence of AFP production. Ten patients with histological evidence of pure yolk sac (endodermal sinus) tumours all had raised levels. Teratomas containing yolk sac (elements may or may not be associated with raised serum levels. Trophoblastic (choriocarcinomatous) elements in a teratoma were not normally associated with high values. Fourteen patients with teratomas had elevated levels in the absence of histologically detectable yolk sac elements. Serum AFP levels often became elevated before clinical evidence of recurrence, so that AFP can act as an effective marker of the course of the disease and its response to therapy in many patients, but recurrent or progressive disease may be present in the absence of raised levels.     

Bilateral testicular germ cell tumors: twenty-year experience at M. D. Anderson Cancer Center

BACKGROUND: The incidence of testicular carcinoma in the United States has increased significantly over the last two decades. Germ cell tumors form the majority of malignant testicular tumors. With advances in diagnosis and therapeutic approaches, germ cell tumors are now highly sensitive to treatment, providing long-term survival. It has been speculated that the incidence of bilateral germ cell tumors may increase due to the improved survival of patients with unilateral germ cell tumors. In this report, the authors present a study of bilateral germ cell tumors of the testis in men who were treated at The University of Texas M. D. Anderson Cancer Center over a 20-year period with emphasis on their incidence, histologic features, and clinical features. METHODS: Between 1978 and 1999, 2431 patients with testicular germ cell tumors were treated at The University of Texas M. D. Anderson Cancer Center. Among these, 24 patients with bilateral germ cell tumors were identified. Clinical records and all available pathology slides of the tumors were reviewed. RESULTS: The overall incidence of bilateral germ cell tumors in the patients with testicular germ cell tumors was 1% (24 of 2431 patients). The incidence was 1.8% (14 of 776 patients) in patients with seminoma and 0.6% (10 of 1655 patients) in patients with nonseminomatous germ cell tumors. Patients with seminoma who were age 相似文献   

Tumour localisation with a radioactively labelled reshaped human monoclonal antibody

A genetically reshaped human IgG1 monoclonal antibody (Hu2PLAP) with anti-tumour specificity, was radiolabelled with Indium-111 by chelation with a new macrocyclic compound (DOTA) which allows the production of stable radioimmunoconjugates for in vivo application. This was used to image seven patients with malignant disease, of whom two had been previously exposed to mouse monoclonal antibodies and had developed human anti-mouse antibodies (HAMA). Successful tumour localisation was seen in the four patients with active disease and antigen positive tumours. No patient showed any antibody responses against Hu2PLAP, but three out of six patients tested showed an immune response against the macrocycle DOTA. Reshaped human monoclonal antibodies with anti-tumour specificity may facilitate repeated administrations of radioactive antibodies, thus allowing new possibilities, both in the diagnosis and treatment of cancer.