Accuracy of germ cell tumor histology and stage within a Canadian cancer registry

INTRODUCTION

Cancer registries are the mainstay for Canadian population-based cancer statistics. Data are collected in provincial and territorial registries, including the Nova Scotia Cancer Registry (NS CR). The goal of this study was to determine the accuracy of NS CR data for germ cell tumors (GCT).

METHODS

This analysis included all NS CR patients diagnosed with GCT from 2006-2015. The date and method of diagnosis, primary site, histology, and stage were recorded from the NS CR and compared to each patient's chart. Any discrepancies between the two sources were reviewed and reasons behind the discrepancies recorded.

RESULTS

A total of 229 patients made up the study cohort. Using NS CR data, 57.6% had seminoma, 34.5% non-seminoma (NSG CT), and 7.9% other. Discrepancies in pathology were noted in 16 patients (7.0%). Using NS CR staging data (available in 185 cases), 71.9% had stage I, 12.4% stage II, 11.9% stage III, and 3.8% other. Discrepancies in stage were noted in 32 patients (17.3%) with NS CR data downstaging eight patients (4.3%) and upstaging 21 patients (11.4%). The site of the primary GCT was discrepant in 12 patients (5.2%). The date of diagnosis was accurate within one week for all patients except one.

CONCLUSIONS

Higher-level NS CR data, such as date of diagnosis and overall pathological diagnosis, appear relatively accurate; however, there are inaccuracies in histological subtype and stage. This study raises awareness of these gaps and highlights key areas for improvement in educating registry personnel who interpret and enter data about the uniqueness of GCT pathology, staging, and interpretation of tumor markers.

Accuracy of germ cell tumor histological subtype and stage within the Canadian cancer registry

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Background: Cancer registries are the mainstay for Canadian population-based cancer statistics and research. Data is collected in provincial and territorial registries including the Nova Scotia Cancer Registry (NSCR). The goal of this study was to determine the accuracy of the NSCR data regarding the diagnosis, primary site, histological subtype, and stage of germ cell tumors (GCT) when compared to the individual pathology reports and staging investigations from the chart. Methods: This analysis included all NSCR patients diagnosed with GCT from 2006-2015. From the NSCR, the date and method of diagnosis, primary site, histology, and stage were recorded. This data was also extracted from each patient’s chart record. Any discrepancies between the two sources were reviewed and reasons behind the discrepancies were recorded. Results: 239 unique patients were identified in the NSCR during the specified time period. Ten were excluded as no chart records were available to confirm accuracy. 229 patients make up the study cohort. Using NSCR data 57.6% had seminoma, 34.5% nonseminoma (NSGCT), and 7.9% other. Discrepancies in pathology were noted in 29 patients (12.7%) for a number of reasons including no appropriate coding option in the NSCR, multiple tumors, biopsy only specimens with misinterpretation of tumor marker elevation, and true coding error. Using NSCR staging data (available in 185 cases) 71.9% had stage I, 12.4% stage II, 11.9% stage III, and 3.8% other. Discrepancies in stage were noted in 33 patients (17.9%) with NSCR data downstaging 10 patients (5.4%) and upstaging 19 patients (10.3%) predominantly due to miscoding patients as stage IS. The site of the primary GCT was discrepant in 12 patients (5.2%) due primarily to difficulty coding post chemotherapy orchiectomy specimens and burnt out primary testicular lesions. The date of diagnosis was accurate within 1 week for all patients except one which differed by several months. Conclusions: Canadian cancer registry data is population based and used for many purposes including policy decisions and research. The NSCR higher level data such as date of diagnosis and overall pathological diagnosis appears relatively accurate. However, there are inaccuracies in more detailed information like histological subtype and stage. This study raises awareness of these gaps. It also highlights key areas for improvement in educating registry personnel who interpret and enter data about the uniqueness of GCT pathology, staging and interpretation of tumor markers.

Combined Transfer Learning and Test-Time Augmentation Improves Convolutional Neural Network-Based Semantic Segmentation of Prostate Cancer from Multi-Parametric MR Images

PURPOSE

Multiparametric MRI (mp-MRI) is a widely used tool for diagnosing and staging prostate cancer. The purpose of this study was to evaluate whether transfer learning, unsupervised pre-training and test-time augmentation significantly improved the performance of a convolutional neural network (CNN) for pixel-by-pixel prediction of cancer vs. non-cancer using mp-MRI datasets.

METHODS

154 subjects undergoing mp-MRI were prospectively recruited, 16 of whom subsequently underwent radical prostatectomy. Logistic regression, random forest and CNN models were trained on mp-MRI data using histopathology as the gold standard. Transfer learning, unsupervised pre-training and test-time augmentation were used to boost CNN performance. Models were evaluated using Dice score and area under the receiver operating curve (AUROC) with leave-one-subject-out cross validation. Permutation feature importance testing was performed to evaluate the relative value of each MR contrast to CNN model performance. Statistical significance (p<0.05) was determined using the paired Wilcoxon signed rank test with Benjamini-Hochberg correction for multiple comparisons.

RESULTS

Baseline CNN outperformed logistic regression and random forest models. Transfer learning and unsupervised pre-training did not significantly improve CNN performance over baseline; however, test-time augmentation resulted in significantly higher Dice scores over both baseline CNN and CNN plus either of transfer learning or unsupervised pre-training. The best performing model was CNN with transfer learning and test-time augmentation (Dice score of 0.59 and AUROC of 0.93). The most important contrast was apparent diffusion coefficient (ADC), followed by Ktrans and T2, although each contributed significantly to classifier performance.

CONCLUSIONS

The addition of transfer learning and test-time augmentation resulted in significant improvement in CNN segmentation performance in a small set of prostate cancer mp-MRI data. Results suggest that these techniques may be more broadly useful for the optimization of deep learning algorithms applied to the problem of semantic segmentation in biomedical image datasets. However, further work is needed to improve the generalizability of the specific model presented herein.

Renal medullary carcinoma and its association with sickle cell trait: a case report and literature review

Renal medullary carcinoma (rmc) is a rare and aggressive renal malignancy that usually presents at an advanced stage, has a poor prognosis, and is associated with sickle cell trait. We present a case of rmc including radiologic and pathology findings, treatment, and outcome. A review of the literature is also presented, with an emphasis on the association of rmc with sickle cell trait, which was an unknown diagnosis in our patient preoperatively.

Intraductal carcinoma of the prostate is an aggressive form of invasive carcinoma and should be graded

Infiltration of the prostatic ducts by prostatic adenocarcinoma occurs relatively frequently, being most commonly associated with high grade disease. It is now recognised that intraductal carcinoma of the prostate (IDCP) has an associated poor prognosis and this is reflected in its histological, molecular and immunohistochemical features. The current recommendation of the World Health Organization is that IDCP not be taken into consideration when grading prostate adenocarcinoma. It is apparent that Gleason did not differentiate between IDCP and stromal invasive carcinoma when developing and validating his grading system, and recent studies suggest that the incorporation of IDCP grading into the overall grading of the specimen provides additional prognostic information.

Model-free prostate cancer segmentation from dynamic contrast-enhanced MRI with recurrent convolutional networks: A feasibility study

Dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) is a method of temporal imaging that is commonly used to aid in prostate cancer (PCa) diagnosis and staging. Typically, machine learning models designed for the segmentation and detection of PCa will use an engineered scalar image called K^trans to summarize the information in the DCE time-series images. This work proposes a new model that amalgamates the U-net and the convGRU neural network architectures for the purpose of interpreting DCE time-series in a temporal and spatial basis for segmenting PCa in MR images. Ultimately, experiments show that the proposed model using the DCE time-series images can outperform a baseline U-net segmentation model using K^trans. However, when other types of scalar MR images are considered by the models, no significant advantage is observed for the proposed model.

Accuracy of kidney cancer diagnosis and histological subtype within Canadian cancer registry data

INTRODUCTION

Provincial/territorial cancer registries (PTCRs) are the mainstay for Canadian population-based cancer statistics. Each jurisdiction captures this data in a population-based registry, including the Nova Scotia Cancer Registry (NSCR). The goal of this study was to describe data from the NSCR regarding renal cell carcinoma (RCC) pathology subtype and method of diagnosis and compare it to the actual pathology reports to determine the accuracy of diagnosis and histological subtype assignment.

METHODS

This retrospective analysis included patients diagnosed with RCC in the NSCR from 2006-2010 with an ICD-O-3 code C64.9 seen or treated in the largest NS health district. From the NSCR, method of diagnosis and pathological diagnosis was recorded. All diagnoses of non-clear-cell RCC (nonccRCC) from NSCR were compared to the actual pathology report for descriptive comparison and reasons for discordance.

RESULTS

723 patients make up the study cohort. 81.3% of patients were diagnosed by nephrectomy, 11.1% radiography, 6.9 % biopsy, and 0.7% autopsy. By NSCR data, 52.8% had clear-cell (ccRCC), 20.5% RCC not otherwise specified (NOS), 12.7% papillary, 4% chromophobe, and the rest had other nonccRCC subtypes. By pathology reports, 69.5% had clear-cell, 15% papillary, 5% chromophobe, only 2.7% RCC NOS. There was a discordance rate of 15.4% between NSCR data and diagnosis from pathology report. Reasons for discordance were not enough information by the pathologist in 45.5%, misinterpretation of report by data coder in 22.2%, and true coding error in 32.3%.

CONCLUSIONS

When using PTCR for RCC incidence data, it is important to understand how the diagnosis is made, as not all are based on pathological confirmation; in this cohort 11% were based on radiology. One must also be aware that clear-cell and non-clear-cell subtypes may differ between the PTCR data and pathology reports. In this study, ccRCC made up 52.8% of the registry diagnoses, but increased to 69.6% on pathology report review. Use of synoptic reporting and ongoing education may improve accuracy of registry data.

Spermatocytic Tumor With Sarcoma: A Rare Testicular Neoplasm

Spermatocytic tumor, formerly known as spermatocytic seminoma, is an uncommon testicular neoplasm which is a distinct clinicopathologic entity from classic seminoma. These tumors are not associated with germ cell neoplasia in situ, other germ cell tumors, or isochromosome 12p. Although typically, these tumors have an excellent prognosis occasional cases are associated with sarcoma and have a very poor prognosis. We present a case of spermatocytic tumor with sarcoma showing a chondrosarcomatous component, discuss the pathologic findings and differential diagnosis and provide follow-up information.

Tumor-to-tumor metastases: papillary thyroid carcinoma into a clear cell renal cell carcinoma

Background

Thyroid metastases to distant sites are uncommon incidents, most often metastasizing to the lungs and bones. Rates of metastasis to the kidney are particularly low, ranging from 2.8–3.8% for papillary and 6–20% for follicular variants of well-differentiated thyroid cancers (WDTCs). In rare instances, tumor-to-tumor metastasis between two true primary neoplasms can occurs. This medical phenomenon has previously occurred as a clear cell renal cell carcinoma (CCRCC) spreading to a WDTC. To our knowledge, this is the first report of a tumor-to-tumor metastasis of a thyroid cancer metastasizing to a primary renal neoplasm.

Case presentation

A 72 year old male presented to the urology clinic with complaints of flank pain. Computed tomography (CT) imaging of the abdomen and pelvis revealed a 5.7 cm solid enhancing mass from the lateral aspect of the right kidney, suspicious for renal cell carcinoma (RCC). The patient subsequently underwent a right laparoscopic radical nephrectomy, and immunohistochemical staining of the 5.5 cm lesion revealed a positive RCC marker to establish a diagnosis of a pT1b ISUP Grade 2 CCRCC. The tumor contained a 3 mm focus of a lesion staining positive for TTF1 and Thyroglobulin, and negative for RCC marker. This finding established a diagnosis of a tumor-to-tumor metastasis of PTC to CCRCC. Subsequent ultrasound and CT of the head and neck revealed a heterogeneously hypodense 3.3 cm mass in the right thyroid lobe, prompting a total thyroidectomy and level VI neck dissection. Pathology revealed a classic variant multifocal PTC and two ipsilateral lymph nodes positive for metastatic PTC. Ultimately, the thyroid specimen was positive for lymphatic vascular invasion, extrathyroidal extension with invasion of the tracheal cartilage, staging as T4aN1aM1. On follow up examination the patient was recovering well, without signs of dysphagia or dysphonia, and showed bilateral mobile vocal cords on laryngoscope examination.

Conclusions

Tumor-to-tumor metastasis between the thyroid and kidney is an extremely rare occurrence, reports of RCC metastases from a WDTC has not yet been reported in the literature. Corroboration of diagnostic imaging findings with immunohistochemistry staining can consolidate a diagnosis of thyroid neoplasm tumor-to-tumor metastasis to a RCC, thereby prompting surgical excision.

Accuracy of kidney cancer diagnosis and histological subtype within cancer registry data

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Background: Cancer registries are the mainstay for population-based cancer statistics including incidence and cancer type. In Canada, each province captures this data in provincial registries including the Nova Scotia Cancer Registry (NSCR).The goal of this study was to describe data from the NSCR about method of diagnosis and kidney cancer (KC) pathology and compare it to the actual pathology reports to determine the accuracy of diagnosis and histological subtype assignment. Methods: This retrospective analysis included patients with KC in the NSCR with an ICD-10-CM code C64.9 (malignant neoplasm of unspecified kidney, except renal pelvis) within the largest provincial metropolitan area from 2006-2010. Method of KC diagnosis (clinical, radiologic, histology, or autopsy) was recorded as was the pathological diagnosis based on WHO classification. All non-clear cell KC (nonccKC) diagnosis from the registry were compared to the actual pathology report (and pathology re-review when necessary) for comparison. Results: 733 pts make up the study cohort. 81.2% of patients were diagnosed based on nephrectomy, 11.5% on radiography, 6.5 % biopsy, and 0.8% autopsy. By registry data 53.1% had clear cell, 20.2% KC not otherwise specified (NOS), 12.7% papillary, 3.8% chromophobe, and many other nonccKC. By pathology reports, 62.2% had clear cell, 13.4% papillary, 4.4% chromophobe, only 2% KC NOS (because most radiological diagnosis were classified this way). A large number of pathological diagnoses make up the other nonccKC and discrepancies between registry data and pathology reports will be described and compared in detail. Conclusions: Registry data is commonly used to report cancer statistics. Registry data may not be accurate for the true incidence of KC since 11.5% were based on radiology alone. Clear cell KC made up 53% of registry diagnosis but 62% on pathology report review. Although papillary and chromophobe incidence did not vary a lot, other types of nonccKC did. This registry data did not differentiate between papillary type I and II. NonccKC should not be considered one entity. One must be aware of the gaps in registry data for KC statistics including overall diagnosis, clear cell and nonccKC subtypes.

Prolactin- and testosterone-induced carboxypeptidase-D correlates with increased nitrotyrosines and Ki67 in prostate cancer

BACKGROUND

Carboxypeptidase-D (CPD) cleaves C-terminal arginine for conversion to nitric oxide (NO) by nitric oxide synthase (NOS). Prolactin (PRL) and androgens stimulate CPD gene transcription and expression, which increases intracellular production of NO to promote viability of prostate cancer (PCa) cells in vitro. The current study evaluated whether hormonal upregulation of CPD and NO promote PCa cell viabilty in vivo, by correlating changes in expression of CPD and nitrotyrosine residues (products of NO action) with proliferation marker Ki67 and associated proteins during PCa development and progression.

METHODS

Fresh prostate tissues, obtained from 40 men with benign prostatic hyperplasia (BPH) or PCa, were flash-frozen at the time of surgery and used for RT-qPCR analysis of CPD, androgen receptor (AR), PRL receptor (PRLR), eNOS, and Ki67 levels. Archival paraffin-embedded tissues from 113 men with BPH or PCa were used for immunohistochemical (IHC) analysis of CPD, nitrotyrosines, phospho-Stat5 (for activated PRLR), AR, eNOS/iNOS, and Ki67.

RESULTS

RT-qPCR and IHC analyses showed strong AR and PRLR expression in benign and malignant prostates. CPD mRNA levels increased ∼threefold in PCa compared to BPH, which corresponded to a twofold increase in Ki67 mRNA levels. IHC analysis showed a progressive increase in CPD from 11.4 ± 2.1% in benign to 21.8 ± 3.2% in low-grade (P = 0.007), 40.7 ± 4.0% in high-grade (P < 0.0001) and 50.0 ± 9.5% in castration-recurrent PCa (P < 0.0001). Immunostaining for nitrotyrosines and Ki67 mirrored these increases during PCa progression. CPD, nitrotyrosines, and Ki67 tended to co-localize, as did phospho-Stat5.

CONCLUSIONS

CPD, nitrotyrosine, and Ki67 levels were higher in PCa than in benign and tended to co-localize, along with phospho-Stat5. The strong correlation in expression of these proteins in benign and malignant prostate tissues, combined with abundant AR and PRLR, supports in vitro evidence that the CPD-Arg-NO pathway is involved in the regulation of PCa cell proliferation. It further highlights a role for PRL in the development and progression of PCa.

Paratesticular fibrous pseudotumour: Intraoperative frozen section analysis can help prevent unnecessary orchiectomy

Paratesticular fibrous pseudotumours are rare intrascrotal lesions, most frequently affecting the testicular tunics. They are benign in nature; however, their pathogenesis is not completely understood. Presenting features are similar to testicular malignancy, which may result in unnecessary radical surgery. It has been suggested that additional diagnostic imaging combined with frozen section analysis may help prevent orchiectomy in these patients. We describe a case of paratesticular fibrous pseudotumour in a 40-year-old male treated with testicle-sparing surgery aided by intraoperative frozen section analysis.

Renal cell carcinoma after neuroblastoma: A case study and review of the literature

We present a case of renal cell carcinoma (RCC) arising in a 26-year-old patient with a history of neuroblastoma. RCC after a previous diagnosis of neuroblastoma is very uncommon, and there have only been 23 reported cases. Using the results of our patient workup, we hoped to determine whether there was a genetic predisposition or iatrogenic cause for the RCC. There is no clear explanation why neuroblastoma survivors are prone to developing RCC. However, genetic predisposition and previous treatment likely play a role. Since there have been few cases described, and few investigations into the genetics of this subtype of RCC, it remains important for individual cases to be added to the literature of this recently described and rare entity.

A rare case of bladder chondroma

Soft tissue chondromas are benign tumours that arise commonly in the hands and feet of adults, but rarely in other locations. Only two prior cases of chondroma of the urinary bladder wall have been reported. We describe a third case and discuss similarities and differences between the three cases reported to date.

Metastatic renal cell carcinoma to the testis: A case report and review of the literature

This is a case of a 68-year-old male who presented with a chief compliant of a testicular mass, which was discovered to be a meta-static lesion of undiagnosed renal cell carcinoma. A computed tomography scan revealed a large right renal mass and multiple pulmonary metastasis. Shortly after diagnosis, the patient was initiated on systemic therapy and received a cytoreductive nephrectomy. We discuss the details of this case as well as a pertinent review of metastatic renal cell carcinoma to the testes.

Carboxypeptidase-D is elevated in prostate cancer and its anti-apoptotic activity is abolished by combined androgen and prolactin receptor targeting

BACKGROUND

Carboxypeptidase-D (CPD) cleaves C-terminal arginine for nitric oxide (NO) production. CPD and NO levels are upregulated by testosterone (T) and prolactin (PRL) to promote survival of prostate cancer (pCa) cells. This study evaluated CPD immunostaining and T/PRL regulation of CPD and NO levels in benign and malignant prostate tissues/cells to determine the role of CPD in pCa.

METHODS

Immunohistochemistry (IHC) and tissue microarrays (TMA) were used to determine CPD immunostaining in prostate specimens. QPCR and immunoblotting were used to quantify CPD mRNA/protein expression in prostate cells. NO production was measured using 4,5-diaminofluorescein diacetate assay.

RESULTS

CPD staining increased from 8.9 ± 3.8% (Mean ± SEM, n = 15) of benign epithelial cell area to 30.9 ± 2.9% (n = 30) of tumor cell area in one set of TMAs (P = 0.0008) and from 5.9 ± 0.9% (n = 45) of benign epithelial cell area to 18.8 ± 1.9% (n = 55) of tumor area in another (P < 0.0001). IHC of prostate tissues (≥50 mm(2)) confirmed increased CPD staining, from 13.1 ± 2.9% in benign (n = 16) to 29.5 ± 4.4% in pCa (n = 31, P = 0.0095). T and/or PRL increased CPD expression in several pCa but not benign cell lines. T and PRL acted synergistically to increase NO production, which was abolished only when receptor antagonists flutamide and Δ1-9-G129R-hPRL were used together.

CONCLUSIONS

CPD immunostaining and T/PRL-stimulated CPD expression were higher in pCa than benign tissues/cells. Elevated CPD increased NO production, which was abolished when both AR and PRLR were inhibited. Our study implicates a critical role for the T/PRL-stimulated CPD-Arg-NO pathway in pCa progression, and suggests that AR+PRLR inhibition is a more effective treatment for pCa.

Abstract 86: Prolactin and testosterone induction of carboxypeptidase-D to promote cell survival is greater in prostate cancer cells than benign prostate cells, and their synergistic action in prostate cancer cells is effectively blocked by receptor antagonists Δ1-9-G129R and flutamide

Introduction: Carboxypeptidase-D (CPD), a membrane-bound metalloproteinase, cleaves C-terminal arginine, which is the substrate of nitric oxide synthase for production of nitric oxide (NO). NO regulates many cellular processes including tumor progression. We have reported that CPD and NO levels were upregulated by testosterone (T) or prolactin (PRL) to enhance survival of prostate cancer (pCa) cells. This study further characterized T/PRL regulation of CPD expression. CPD and NO levels in benign and malignant prostate cells/tissues were compared to determine their roles in pCa development.

Methods: Quantitative RT-PCR (QPCR) was used to measure CPD mRNA levels in human prostate cell lines. Immunohistochemistry (IHC) and tissue microarray (TMA) analysis were used to compare CPD staining in prostate specimens. NO production was measured using 4,5-diaminofluorescein diacetate (DAF-2DA) assay.

Results: QPCR analysis showed that CPD mRNA levels were not significantly altered in the benign prostate cell lines BPH-1 and RWPE1, as compared to a 3-4-fold increase in the pCa cell line LNCaP, following T or PRL treatment (P&lt;0.01, n=3-6). T or PRL caused similar increases in other pCa cell lines (22Rv1, MDAPCa2b and PC-3), in which the androgen receptor (AR) and/or PRL receptor (PRLR) were expressed. DAF-2DA assays showed that NO levels were increased &lt;1.6-fold in benign cells, compared to &gt;3.5-fold in LNCaP cells after T/PRL stimulation. In LNCaP cells, T and PRL acted synergistically to upregulate NO, but were maximally suppressed when both receptors were inhibited with flutamide and Δ1-9-G129R in combination. Consistent with these results, TMA analysis showed significantly increased CPD staining from 8.9±3.8% (mean±SEM, n=18) of benign epithelial cell area to 30.9±2.9% (n=79) of tumor cell area (P&lt;0.001). Endothelial cells in blood vessels associated with tumor were more likely to show positive staining than vessels of benign tissue (P&lt;0.0001). A second TMA also showed increased CPD staining from 5.6±0.9% (n=48) in benign prostatic hyperplasia (BPH) to 17.9±2.1% (n=88) in pCa. TMA results were corroborated by IHC assessment of large (≥50mm2) prostate tissues from 35 men, where CPD staining increased from 13.1±2.9% in BPH to 29.5±4.4% in pCa.

Conclusion: T/PRL-stimulated CPD mRNA levels were higher in tumor than in benign prostate cell lines. Likewise, CPD protein levels were higher in cancer than benign prostate specimens. Elevated CPD levels increased NO production, which was maximally suppressed when both the AR and PRLR were inhibited. Our results suggest that inhibition of both the AR and PRLR may be a more effective treatment for pCa and implicate the potential usefulness of the CPD-Arg-NO pathway as a therapeutic target for pCa.

Citation Format: Catherine K. L. Too, Lynn N. Thomas, Jennifer Merrimen. Prolactin and testosterone induction of carboxypeptidase-D to promote cell survival is greater in prostate cancer cells than benign prostate cells, and their synergistic action in prostate cancer cells is effectively blocked by receptor antagonists Δ1-9-G129R and flutamide. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 86. doi:10.1158/1538-7445.AM2013-86

Adult granulosa cell tumor of the testicle

We report a rare case of adult granulosa cell tumor of the testis in a 68-year-old man. A case and literature review of the associated clinical features, histopathological characteristics and immunochemistry are presented. The tumor is typically slow growing but has a higher risk of malignancy when > 5 cm. Our patient was disease-free 18 months following a right radical orchiectomy.