Small RNAs in the peripheral blood discriminate metastasized from non-metastasized seminoma.

BACKGROUND: We aimed to better discriminate metastasized (lymphogen/occult/both combined) from non-metastasized seminoma based on post-transcriptional changes examined in the peripheral blood. METHODS: Total RNAs including small RNAs were isolated from the peripheral blood of patients suffering from metastasized testicular tumours (lymphogen, n = 5, clinical stage IIb/c; occult, n = 5, clinical stage I) and non-metastasized patients (n = 5, clinical stage I). Small RNA next generation sequencing (SOLID, Life Technologies) was employed to examine post-transcriptional changes. We searched for small RNAs showing at least 50 reads and a significant ≥ 2-fold difference using peripheral blood small RNAs of non-metastasized tumours as the reference group. Candidate small RNAs were examined in univariate logistic regression analysis and combinations of two small RNAs were further examined using support vector machines. RESULTS: On average 1.3 x 10(7), 1.2 x 10(7) and 1.2 x 10(7) small RNA reads were detectable in non-metastasized, lymphogen and occult metastasized seminoma, respectively of which 73-76% remained after trimming. From these between 80-82% represented annotated reads and 7.2-7.8% (1.6-1.7 x 10(4)) were annotated small RNA tags. Of them 137 small RNAs showed > 50 reads and a ≥ two-fold difference to the reference. In univariate analysis we detected 33-35 different small RNAs which significantly discriminated lymphogen/occult/combined metastasized from non-metastasized seminoma and among these different comparisons it were the same small RNAs in 44-79%. Many combinations of two of these small RNAs completely discriminated metastasized from non-metastasized seminoma irrespective of the metastasis subtype. CONCLUSIONS: Metastasized (either lymphogen or occult) seminoma can be completely discriminated from non-metastasized seminoma with a combination of two small RNAs measured in the peripheral blood.

Misuse of tumor marker levels leads to an insufficient International Germ Cell Consensus Classification (IGCCCG) risk group assignment and impaired treatment.

BACKGROUND: Metastatic germ cell tumors of the testis (GCTs) are risk-stratified according to the International Germ Cell Cancer Collaborative Group (IGCCCG) classification system. This risk classification is based on anatomical risk factors as well as tumor marker levels of AFP, HCG, and LDH assessed pre-chemotherapy after orchiectomy treatment. An incorrect classification is possible when pre-orchiectomy marker levels are used, possibly resulting in over- or undertreatment of patients. The aim was to investigate the potential frequency and clinical relevance of incorrect risk stratification using pre-orchiectomy tumor marker levels. METHODS: A multicenter registry analysis, including patients with metastasized nonseminomatous GCT (NSGCT), was conducted by investigators of the German Testicular Cancer Study Group (GTCSG). Based on the marker levels at different timepoints, IGCCCG risk groups were calculated. The agreement was tested using Cohen's kappa. RESULTS: A total of 672 of 1910 (35%) patients were diagnosed with metastatic NSGCTs, and 523 (78%) had sufficient data for 224 follow-up data points. By using pre-orchiectomy tumor marker levels, 106 patients (20%) would have been incorrectly classified. Seventy-two patients (14%) were classified into a higher risk category, and 34 patients (7%) were classified into a lower risk category. Cohen's kappa was 0.69 (p < 0.001), showing a strong agreement between the use of both marker timepoints. The treatment of misclassified patients would have resulted in an overtreatment of 72 patients or undertreatment of 34 patients. CONCLUSIONS: The use of pre-orchiectomy tumor marker levels may lead to an incorrect risk classification and might subsequently lead to under- or overtreatment of patients.

Late toxicities and recurrences in patients with clinical stage I non-seminomatous germ cell tumours after 1 cycle of adjuvant bleomycin, etoposide and cisplatin versus primary retroperitoneal lymph node dissection - A 13-year follow-up analysis of a phase III trial cohort.

BACKGROUND: One cycle of adjuvant chemotherapy with bleomycin, etoposide and cisplatin (BEP) has shown superiority in recurrence-free survival over retroperitoneal lymph node dissection (RPLND) in patients with clinical stage (CS) I non-seminomatous germ cell tumours (NSGCTs) of the testis in the setting of a phase III trial. We report the recurrences and late toxicities of this study after 13 years of follow-up. METHODS: Questionnaires from 382 patients with CS I NSGCT treated with 1 cycle of adjuvant BEP (arm A) or RPLND + two cycles of adjuvant BEP in cases of pathological stage II disease (arm B) were evaluated regarding recurrences and late toxicity. Overall, information on recurrence status was available in 337 patients, and 170 questionnaires were evaluable for toxicity (arm A: 95; arm B: 75). RESULTS: With a median follow-up of 13.8 years (0-22), 3 patients (1.6%) in arm A and 16 patients (8.4%) in arm B experienced recurrence. The 15-year PFS in arm A/B was 99% (CI 96-100%)/92% (CI 89-99%) (p = 0.0049). The 15-year OS in arm A/B was 93% (CI 87-97%)/93% (CI 86-97%) (p = 0.83). Eight patients (4.2%) in arm A and four patients (2.1%) in arm B showed metachronous secondary testicular cancer (p = 0.26). Five patients (2.6%) in arm A and four patients (2.1%) in arm B developed other malignancies. Toxicities were not significantly different apart from retrograde ejaculation, which occurred more frequently after RPLND (10% versus 24%, p = 0.01). CONCLUSIONS: With long-term observation, one cycle of BEP remains superior to RPLND in preventing recurrence and was tolerated without any clinically relevant long-term toxicities.

Liquid Biopsy Using Whole Blood from Testis Tumor and Colon Cancer Patients-A New and Simple Way?

Tumor cells shed exosomes, which are released to the blood. Detecting tumor-derived exosomes containing RNA in plasma (liquid biopsy) is currently being investigated for early identification of occult metastases or relapses. Isolation of exosomes is laborious, resulting in low RNA yields. As a more robust (but less sensitive) alternative, the authors examined whether whole blood can be used as well. Tumor samples from nonmetastasized seminoma (n = 5) and colon cancer patients (n = 6) were taken during surgery. Whole-blood samples were taken before and 5-7 d after surgery. A whole genome mRNA microarray screening was performed. Candidate genes were selected based on two criteria: (1) gene expression in the presurgical whole-blood sample/tumor biopsy; and (2) a two-fold decrease in the copy number of candidate genes was expected in the postsurgical whole-blood sample 5-7 d after intervention, relative to the presurgical blood sample. The rationale behind this is the loss of tumor material in the body and the decline in the release of tumor-derived RNA in exosomes. For both tumor entities and for each patient, several hundred candidate genes could be identified. In a group-wise comparison, 20 candidate genes could be identified in the seminoma and 32 in the colon cancer group. These findings indicate that whole blood might be suitable for a liquid biopsy. However, this study identified the short period after surgery (5-7 d) as a possible confounder. The authors plan to add an additional time point several weeks after the operation to discriminate tumor candidate genes from genes induced by the surgery.

Correcting false gene expression measurements from degraded RNA using RTQ-PCR.

This paper describes a method allowing correcting false gene expression measured on highly degraded RNA using real-time quantitative reverse transcription-polymerase chain reaction (RTQ-PCR). RNA was isolated from different models (in vitro cell lines, in vivo models of human and dog) and different tissue types. In vitro RNA degradation and modeling of in vivo degradation were applied on intact and degraded total RNA. Gene expression (eg, Bcl-2, GAPDH, PGK, PSME3, RAB2, BAX) was measured using RTQ-PCR. 18S rRNA proved to be the most constant house-keeping gene. Less than 10-fold degraded RNA can be quantified correctly when using 18S rRNA for normalization purposes. Higher-fold degraded RNA can be quantified correctly up to a precision that is comparable to RTQ-PCR measurements on intact RNA when simulating the RNA-species and tissue-specific degradation kinetic.

Clinically apparent and occult metastasized seminoma: almost indistinguishable on the transcriptional level.

PURPOSE: The aim of the present study was to examine the biological differences between seminomas with occult and clinically apparent metastases at the time of diagnosis of the primary tumor to gain insight into the biology of these tumors and facilitate the identification of novel predictors of seminoma metastasis. MATERIALS AND METHODS: Total RNA including small RNAs was isolated from testicular tumors of patients with pure seminoma presenting with lymphogenic metastasis (n = 5, clinical stage IIb/c) and occult metastasis (n = 5, clinical stage I). The regulation of biological processes was examined (1) throughout the mRNA transcriptome (whole genome microarrays, 8×60 K Array, Agilent with 4 samples/group) and (2) the miRNA transcriptome employing small RNA next generation sequencing (SOLID, Life Technologies with 5 samples/group). Protein coding genes (mRNAs) and small RNAs showing a significant (≥2-fold) difference between the groups were identified. Finally (3), we examined 95 candidate miRNAs in 36 apparent metastasized and another 5 occult metastasized seminoma using logistic regression analysis. RESULTS: Among 19,596 genes, on average 12,894 mRNAs appeared expressed (65.8%, SD+/-2.4; range, 62.0-69.3%) and 16.99×106/13.94×106 small RNA reads were identified for apparent/occult metastasized seminoma. These reads on average convert into 9,901/9,675 small RNAs including 422/404 mature microRNAs. None of these mRNAs/small RNAs met our selection criteria for candidate genes. From 95 candidate miRNAs 44 appeared expressed, with 3 of them showing weak but significant (p = 0.05) differences among both groups. CONCLUSIONS: Occult and apparent metastasized seminomas are biologically almost indistinguishable and probably represent no separate tumor entities. These findings may simplify future research on seminoma metastasis.

A gene signature of primary tumor identifies metastasized seminoma.

BACKGROUND: The aim of this study was the prediction of metastatic status in seminoma based on examination of the primary tumor. METHODS: Total RNA was isolated from metastasized seminoma (n = 10, T1N1-2M0), non-metastasized seminoma (n = 21, T1-3N0M0), and corresponding normal tissues. Pooled RNA from 10 biopsies of each tissue type was hybridized on whole genome microarrays for screening purposes. Ninety-two selected gene candidates were quantitatively examined using real-time quantitative polymerase chain reaction (RTQ-PCR). RESULTS: Agreement in gene expression was 88% between the whole genome microarrays and RTQ-PCR. Metastasized seminoma showed 1,912 up-regulated and 2,179 down-regulated genes with ≥ 2-fold differences in gene expression compared non-metastasized seminoma. RTQ-PCR of selected genes showed that mean gene expression values were significantly reduced in metastasized compared with non-metastasized seminoma. The presence of metastases could be predicted based on an 85-gene expression signature by using logistic regression. Sensitivity and accuracy of the 10-fold cross-validation model were 77.8% and 84.2%, respectively. CONCLUSION: A logistic regression model using an 85 gene expression signature allowed identification of metastasized seminoma from the primary tumor with a sensitivity of 77.8%.

Imaging studies in the diagnosis of urogenital trauma.

UNLABELLED: Polytraumatized patients often present with urological injuries. After hemodynamic stability is maintained urologists are consulted to evaluate diagnostic and therapeutic interventions. The following article describes how to handle the work-up of patients with injuries to specific urogenital organs: the importance of clinical examination, ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), angiography as well as organ-specific radiologic studies such as intravenous pyelography or cystography are discussed. CONCLUSION: Even though injuries to the urogenital tract are rarely initially life--threatening, a fast, reliable and adequate diagnostic algorithm has to be established to avoid any delay of specific treatment. Urologists should be familiar with the indications, range and accuracy of these procedures in the diagnosis of urogenital trauma.

Comparative analysis of different apoptosis detection methods in human testicular cancer.

In situ end-labeling (ISEL) of internucleosomal 3' DNA strand breaks and the morphological proof of nuclear chromatin condensation are two widely used methods to investigate and quantify apoptosis. However, it is still unclear whether both processes are linked with each other and if quantifying apoptosis by both methods leads to comparable results. Therefore, internucleosomal DNA fragmentation and chromatin condensation were measured simultaneously on double-fluorescence-labeled sections of 62 testicular tumors (47 nonseminomatous tumors and 15 seminomas) using immunofluorescence microscopy. Different apoptotic indices (AI), based on DNA fragmentation and/or morphological criteria were determined. The AI were quantified. Morphologically obtained AI ranged between 1.99% for non-seminomatous tumors and 0.88% for seminomas. The detection of DNA fragmentation values ranged between 8.15% for non-seminomatous tumors and 2.70% for seminomas. Only about 30% of all apoptotic cells could be detected with the morphological method compared to 80% using ISEL in both tumor entities. Therefore, the equivalence of investigations using different apoptosis detection methods in human testicular cancer seems questionable.