New tumor markers of testis cancer

Testicular Tumor Markers in the Spermatic Vein - Correlation to Pathology, Stage and Outcome

OBJECTIVE

To report our findings in patients with determination of testicular tumor markers from the vena spermatica during inguinal orchiectomy.

METHODS

In a retrospective setting, data of patients who underwent inguinal orchiectomy between January 2004 and December 2014 were analyzed. Cubital and testicular vein tumor markers were assessed and correlated to histology, clinical stage and outcome.

RESULTS

A total of 90 patients (seminomatous: n = 53, non-seminomatous: n = 37) with a median age of 37 years were included. The mean follow-up was 109 months. Overall, 60% (n = 54) of patients had one or more positive tumor marker level in the cubital vein vs 88.9% (n = 80) in the testicular vein. Median tumor marker levels of hCGβ in cubital and testicular vein were 1.9 U/l and 30.8U/l; the respective values for AFP were 2.9ng/ml and 2.4ng/ml and for hPLAP 49.9 mU/l and 418.9 mU/l. Differences in cubital vs testicular vein positivity were stage dependant and highest for pT1. Patients with seminomatous tumors had peripheral positivity of 59.3% vs 88.9% in the testicular vein (P = 0.003); in non-seminomatous patients the respective values were 61.1% and 88.9% (P = 0.02). All recurrent cancer patients under active surveillance (n = 5) were positive in the testicular vein.

CONCLUSION

Virtually all testicular cancers shed tumor markers in the circulation. Differences in marker positivity (testicular vs testicular vein) were stage dependent (greatest in pT1), largely independent of histology and highest for hCGβ. The prognostic value of testicular vein sampling remains speculative.

Germ cell-specific localization of immunoreactive riboflavin carrier protein in the male golden hamster: appearance during spermatogenesis and role in sperm function

Riboflavin carrier protein (RCP) is a phosphoglycoprotein (37 kDa) that is well studied in chicken. An immunologically cross-reacting protein was identified in mammals and active immunization of male rats and bonnet monkeys with chicken RCP lead to an approximately 80% reduction in fertility. However, the physiological mechanism responsible for inhibition of male fertility has not been investigated. Moreover, information on the cell type-specific localization and the origin of immunoreactive RCP during spermatogenesis is extremely limited. Hence, studies were carried out to determine the pattern of expression of immunoreactive RCP during spermatogenesis and its role in sperm function in the golden hamster. Immunoreactive RCP was germ cell-specific, found to be associated with the acrosome-organizing region of early spermatids and showed interesting patterns of immunolocalization during late stages of spermiogenesis. Mature spermatozoa exhibited acrosome-specific localization, mainly in the peri-acrosomal membrane. The immunoreactive protein was undetectable in (non)gonadal somatic cells tested. The protein had a molecular mass of 45-55 kDa and was biosynthesized by round spermatids. The acrosome-specific localization of immunoreactive RCP was unchanged during capacitation, but it was substantially lost during acrosome reaction. Functional studies indicated that treatment of spermatozoa with anti-RCP antibodies did not have any effect on either capacitation or acrosome reaction, but markedly reduced the rate of sperm penetration into zona-free hamster oocytes. These results show the existence of male germ cell-specific immunoreactive RCP, having a potential role in sperm-egg interaction in hamsters. Also the pattern of immunoreactive-RCP localization makes it an ideal marker to monitor development of acrosome in mammalian spermatozoa.

Expression of the normal epithelial cell-specific 1 (NES1; KLK10) candidate tumour suppressor gene in normal and malignant testicular tissue

The normal epithelial cell-specific 1 (NES1) gene (official name kallikrein gene 10; KLK10) is a new member of the expanding human kallikrein gene family and encodes for a secreted serine protease. Experimental evidence suggests that NES1 controls normal cell growth and may function as a tumour suppressor. NES1 is down-regulated during breast cancer progression. The NES1 gene is highly expressed in testicular as well as in other tissues. In this study, we investigated the expression level of the NES1 gene in cancerous and normal testicular tissues with reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. In all 14 primary testicular germ-cell tumours examined, the NES1 gene expression was markedly reduced compared to adjacent (paired) normal tissues. We further examined 6 randomly selected primary germ-cell tumours and 8 normal tissues (obtained from different individuals). We confirmed the differential expression of the NES1 gene in germ-cell tumours (GCT) and pre-malignant carcinoma in situ (CIS). Our findings suggest that NES1 may act as a tumour suppressor and may play a role in the pathogenesis and progression of this malignancy.

The role of the histopathologist in the management of testicular germ cell tumour in adults

In the last 20--30 years the availability of effective chemotherapy and more accurate clinical staging has greatly improved the prognosis for patients with testicular germ cell tumours. Initially, such treatment appeared to diminish the role of histopathology to the distinction between seminoma and nonseminomatous germ cell tumour (NSGCT) in the primary specimen. However, histopathology has evolved as a prognostic tool indicating the risk of relapse in various defined clinical contexts thereby facilitating therapeutic decisions. The clinical emphasis has been on quality of life and reduction of therapy both in terms of the number of patients treated and the number of chemotherapy courses given to each patient. The treatment of adult testicular germ cell tumours may differ between countries but protocols are established. Therefore it is appropriate to discuss the role of histopathology during this era of relative therapeutic stability.

Treatment of testicular tumours based on risk factors

Germ cell cancer is highly sensitive to cisplatinum-based chemotherapy, resulting in cure rates of over 90% for patients with minimal metastatic disease or low tumour markers, 70% for patients with intermediate prognosis features, and 50% for patients with poor prognosis criteria. Whereas current clinical studies aim to improve the survival of patients with poor prognosis by means of high-dose chemotherapy, or the survival of intermediate prognosis patients by more intensive chemotherapy, for patients with good prognosis the reduction of doses, number of drugs or cycles is investigated to reduce the short-term and, in particular, long-term treatment sequelae. However, apart from these clinical studies, the current treatment standard of three cycles of platinum/etoposide/bleomycin for good prognosis patients and four cycles for intermediate and poor prognosis patients with advanced germ cell cancer has not been changed by recent trial results. The excellent cure rate with cisplatinum-based chemotherapy in the case of early metastatic disease with three cycles of platinum/etoposide/bleomycin as well as the high efficacy of adjuvant chemotherapy with two cycles of platinum/etoposide/bleomycin in the case of microscopic disease did change the treatment standards in stage I and II non-seminomatous germ cell cancer, with defined treatment options depending on prognostic factors. The treatment of testicular cancer based on prognostic factors is mandatory in all stages of seminoma and non-seminoma; however, molecular biological factors might make a major contribution to a more precise determination of prognosis and therefore enable a tailored selection of an individual treatment in the future.