Propensity-matched Analysis of Open Versus Robotic Primary Retroperitoneal Lymph Node Dissection for Clinical Stage II Testicular Cancer.

BACKGROUND: Open retroperitoneal lymph node dissection (O-RPLND) is the accepted standard surgical approach to treat retroperitoneal nodal disease in testis cancer. Increasingly, robotic RPLND (R-RPLND) is being performed due to the potential for lower blood loss, shorter length of stay, and accelerated recovery. OBJECTIVE: We have performed a propensity score matching (PSM) analysis comparing the survival and perioperative outcomes of O- and R-RPLND. DESIGN, SETTING, AND PARTICIPANTS: Analyzing the data from all patients who underwent primary RPLND at our center between 1990 and 2022, we used PSM to create a 2:1 (O-RPLND:R-RPLND) matched cohort. INTERVENTION: Primary O-RPLND versus R-RPLND. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoint was time to relapse. The secondary endpoints included operating time, length of stay, estimated blood loss (EBL), and surgical complications. Relapse-free survival rates were calculated using the Kaplan-Meier method, and log-rank tests were used to compare perioperative outcomes of O-RPLND versus R-RPLND. KEY FINDINGS AND LIMITATIONS: A total of 178 patients underwent primary RPLND: 137 O-RPLND and 41 R-RPLND. After PSM, 26 patients in the R-RPLND group were matched with 38 in the O-RPLND group. After matching, no significant baseline differences were noted. After a median follow-up of 23.5 mo (interquartile range 4.4-59.2), one (3.8%) relapse was noted in the R-RPLND group versus three (7.8%) in the O-RPLND group; however, this was not significant (hazard ratio 0.65, 95% confidence interval 0.07-6.31, p = 0.7097). No in-field relapses occurred in either cohort. R-RPLND was associated with a shorter length of stay (1 vs 5 d, p < 0.0001) and lower EBL (200 vs 300 ml, p = 0.032), but longer operative time (8.8 vs 4.3 h, p < 0.0001). CONCLUSIONS: R-RPLND offers low morbidity and improved perioperative outcomes, while maintaining oncologic efficacy of the open approach. PATIENT SUMMARY: To the best of our knowledge, this is the first study to compare open and robotic retroperitoneal lymph node dissection (R-RPLND) using a propensity score-matched system. We encourage the discussion and inclusion of primary R-RPLND into the standard of care algorithm for patients with de novo clinical stage (CS) II and relapsed CS I with CS II equivalent disease.

Prognostic Factor Risk Groups for Clinical Stage I Seminoma: An Individual Patient Data Analysis by the European Association of Urology Testicular Cancer Guidelines Panel and Guidelines Office.

BACKGROUND: The relapse rate in patients with clinical stage I (CSI) seminomatous germ cell tumor of the testis (SGCTT) who were undergoing surveillance after radical orchidectomy is 4-30%, depending on tumor size and rete testis invasion (RTI). However, the level of evidence supporting the use of both risk factors in clinical decision-making is low. OBJECTIVE: We aimed to identify the most important prognostic factors for relapse in CSI SGCTT patients. DESIGN, SETTING, AND PARTICIPANTS: Individual patient data for 1016 CSI SGCTT patients diagnosed between 1994 and 2019 with normal postorchidectomy serum tumor marker levels and undergoing surveillance were collected from nine institutions. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Multivariable Cox proportional hazard regression models were fit to identify the most important prognostic factors. The primary endpoint was the time to first relapse by imaging and/or markers. Relapse probabilities were estimated by the Kaplan-Meier method. RESULTS AND LIMITATIONS: After a median follow-up of 7.7 yr, 149 (14.7%) patients had relapsed. Categorical tumor size (≤2, >2-5, and >5 cm), presence of RTI, and lymphovascular invasion were used to form three risk groups: low (56.4%), intermediate (41.3%), and high (2.3%) risks with 5-yr cumulative relapse probabilities of 8%, 20%, and 44%, respectively. The model outperformed the currently used model with tumor size ≤4 versus >4 cm and presence of RTI (Harrell's C index 0.65 vs 0.61). The low- and intermediate-risk groups were validated successfully in an independent cohort of 285 patients. CONCLUSIONS: The risk of relapse after radical orchidectomy in CSI SGCTT patients under surveillance is low. We propose a new risk stratification model that outperformed the current model and identified a small subgroup with a high risk of relapse. PATIENT SUMMARY: The risk of relapse after radical orchidectomy in patients with clinical stage I seminomatous germ cell tumor of the testis is low. We propose a new risk stratification model that outperformed the current model and identified a small subgroup with a high risk of relapse.

Role of Lactate Dehydrogenase in Identifying Relapse for Patients With Stage I Testicular Cancer on Surveillance.

PURPOSE: Tumor markers alpha-fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase assume a key role in the management of testicular germ cell tumors. While alpha-fetoprotein and human chorionic gonadotropin have modest sensitivity and specificity for germ cell tumors, lactate dehydrogenase has weak sensitivity and specificity. We explored the utility of lactate dehydrogenase in identifying relapse among stage I seminomatous and nonseminomatous germ cell tumors on surveillance. MATERIALS AND METHODS: Patients with a history of stage I testicular germ cell tumors were identified from a prospectively maintained database at the Princess Margaret Cancer Centre from December 1980 to May 2021 and surveyed according to established institutional algorithm guidelines. The utility of lactate dehydrogenase elevation to independently detect germ cell tumor relapse was examined. RESULTS: Among 1,014 seminoma and 676 nonseminomatous germ cell tumor patients, 176 and 176 patients relapsed with a median time to relapse of 13.6 and 8.9 months, respectively. Imaging alone was the most common mode of relapse detection in 144 and 74 of seminoma and nonseminomatous germ cell tumor patients, respectively. Lactate dehydrogenase was elevated in 49 cases of seminoma and 38 cases of nonseminomatous germ cell tumors at relapse, but was never the sole relapse indicator. Among 350 seminoma and 311 nonseminomatous germ cell tumor patients who never relapsed, 210 and 233, respectively, had at least 1 elevated lactate dehydrogenase value. CONCLUSIONS: Lactate dehydrogenase alone did not independently contribute to early relapse detection in stage I seminoma or nonseminomatous germ cell tumor. Elevated lactate dehydrogenase values were documented in a high proportion of nonrelapsing seminoma and nonseminomatous germ cell tumor cases.

Association Study between Polymorphisms in DNA Methylation-Related Genes and Testicular Germ Cell Tumor Risk.

BACKGROUND: Testicular germ cell tumors (TGCT), histologically classified as seminomas and nonseminomas, are believed to arise from primordial gonocytes, with the maturation process blocked when they are subjected to DNA methylation reprogramming. SNPs in DNA methylation machinery and folate-dependent one-carbon metabolism genes have been postulated to influence the proper establishment of DNA methylation. METHODS: In this pathway-focused investigation, we evaluated the association between 273 selected tag SNPs from 28 DNA methylation-related genes and TGCT risk. We carried out association analysis at individual SNP and gene-based level using summary statistics from the Genome Wide Association Study meta-analysis recently conducted by the international Testicular Cancer Consortium on 10,156 TGCT cases and 179,683 controls. RESULTS: In individual SNP analyses, seven SNPs, four mapping within MTHFR, were associated with TGCT risk after correction for multiple testing (q ≤ 0.05). Queries of public databases showed that three of these SNPs were associated with MTHFR changes in enzymatic activity (rs1801133) or expression level in testis tissue (rs12121543, rs1476413). Gene-based analyses revealed MTHFR (q = 8.4 × 10-4), methyl-CpG-binding protein 2 (MECP2; q = 2 × 10-3), and ZBTB4 (q = 0.03) as the top TGCT-associated genes. Stratifying by tumor histology, four MTHFR SNPs were associated with seminoma. In gene-based analysis MTHFR was associated with risk of seminoma (q = 2.8 × 10-4), but not with nonseminomatous tumors (q = 0.22). CONCLUSIONS: Genetic variants within MTHFR, potentially having an impact on the DNA methylation pattern, are associated with TGCT risk. IMPACT: This finding suggests that TGCT pathogenesis could be associated with the folate cycle status, and this relation could be partly due to hereditary factors.

Safety of Minimizing Intensity of Follow-up on Active Surveillance for Clinical Stage I Testicular Germ Cell Tumors.

Background: We have recommended active surveillance as the preferred management option for clinical stage I (CSI) testicular germ cell tumors (GCTs) since 1980. Over time, the recommended intensity of surveillance has decreased; however, the impact on relapse detection has not been investigated. Objective: To examine relapse rate, time to relapse, extent of disease, and burden of treatment at relapse across decreasing surveillance intensity over time. Design setting and participants: CSI GCT patients under active surveillance from 1981 to 2021 were included in this study. Outcome measurements and statistical analysis: Through four major iterations in both nonseminomatous (NSGCT) and seminoma surveillance schedules, visit frequency, blood testing, and imaging have been decreased successively. Low-dose, noncontrast computed tomography (CT) scans were adopted in 2011. Categorical variables and time to relapse were compared using chi-square and Fisher's exact or Kruskal-Wallis test, respectively. Results and limitations: A total of 1583 consecutive patients (942 with seminoma and 641 with NSGCT) were included. In seminoma, chest x-rays were reduced from 13 to one and CT scans were reduced from 20 to ten. Relapse rate, time to relapse, N or M category, and International Germ Cell Cancer Collaborative Group (IGCCCG) classification did not change. In NSGCT, chest x-rays were reduced from 27 to zero and CT scans were reduced from 11 to five. Relapse rate (from 46.2% to 21.2%, p = 0.002) and the median time to relapse (from 6.54 to 4.47 mo, p = 0.025) decreased. No difference in relapsed disease burden was identified by N, M, and S category or IGCCCG classification. Treatment burden at relapse and GCT cancer deaths remained similar for seminoma and NSGCT. Limitations include the retrospective design and large time period covered. Conclusions: Despite considerable reductions in surveillance intensity, we did not observe an increase in disease extent, treatment burden, or GCT cancer deaths upon relapse. These results support that our current lower-intensity active surveillance schedules are safe for managing CSI GCT. Patient summary: Our current reduced-intensity surveillance schedules for clinical stage I germ cell tumors appear to be safe.

Identification of 22 susceptibility loci associated with testicular germ cell tumors.

Testicular germ cell tumors (TGCT) are the most common tumor in young white men and have a high heritability. In this study, the international Testicular Cancer Consortium assemble 10,156 and 179,683 men with and without TGCT, respectively, for a genome-wide association study. This meta-analysis identifies 22 TGCT susceptibility loci, bringing the total to 78, which account for 44% of disease heritability. Men with a polygenic risk score (PRS) in the 95th percentile have a 6.8-fold increased risk of TGCT compared to men with median scores. Among men with independent TGCT risk factors such as cryptorchidism, the PRS may guide screening decisions with the goal of reducing treatment-related complications causing long-term morbidity in survivors. These findings emphasize the interconnected nature of two known pathways that promote TGCT susceptibility: male germ cell development within its somatic niche and regulation of chromosomal division and structure, and implicate an additional biological pathway, mRNA translation.

Long-term Surveillance of Patients with Complete Response Following Chemotherapy for Metastatic Nonseminomatous Germ Cell Tumor.

BACKGROUND: There is controversy regarding the management of patients with normal markers and residual masses (≤1 cm) after chemotherapy for nonseminomatous germ cell tumors (NSGCTs). OBJECTIVE: To determine long-term outcomes of a surveillance strategy in such patients. DESIGN, SETTING, AND PARTICIPANTS: A retrospective review of our multidisciplinary testicular cancer database was performed. All patients who underwent primary chemotherapy for metastatic NSGCTs were identified between 1981 and 2016. A complete response (CR) was defined as normalization of serum tumor markers and a ≤1 cm residual mass in the largest axial dimension following chemotherapy. All such patients were surveilled. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Outcome variables of interest were time to death, time to cancer-specific survival, and time to relapse. Overall survival and relapse-free survival were calculated using the Kaplan-Meier method, and the cumulative incidence of cause-specific survival rates was calculated using competing risk analysis. The impact of risk group and chemotherapy regimen on relapse-free survival was assessed using log-rank test. RESULTS AND LIMITATIONS: During the study period, 1429 metastatic germ cell tumor patients were treated with primary chemotherapy. CR was achieved in 191 (18.5%) NSGCT patients. The median age at diagnosis was 27.4 yr, with a median follow-up of 81.1 mo. The majority had American Joint Committee on Cancer stage II at diagnosis (I: 23.8%; II: 49.2%; III: 27%) and International Germ Cell Cancer Collaborative Group good-risk disease (good: 78%; intermediate: 17.8%; poor: 4.2%). Of the 191 patients with a CR, 175 (91.6%) never relapsed and remain disease free. Sixteen (8.4%) patients relapsed after a median of 11.3 mo (range 1-332 mo), with over half (nine patients; 4.7%) relapsing in the retroperitoneum only and salvaged successfully with postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) alone. Of these nine patients, only two (1%) had viable disease in the PC-RPLND specimen. The remaining seven patients had relapses outside the retroperitoneum and received salvage chemotherapy ± postchemotherapy resection. Overall, nine (4.7%) patients have died, but only four (2.1%) from testis cancer. CONCLUSIONS: Our data, the largest series to date, confirm that surveillance is safe and effective for men who achieve a CR following chemotherapy for metastatic NSGCTs. PATIENT SUMMARY: Surveillance is a safe strategy for patients who achieve a complete response following chemotherapy for metastatic testis cancer.

Clinical dilemmas in local and regional testis cancer.

At the Canadian Testis Cancer Workshop, the multidisciplinary management of testis cancer care was discussed. The two-day workshop involved urologists, medical and radiation oncologists, pathologists, radiologists, physician's assistants, residents, fellows, nurses, patients, and patient advocacy group members.This review summarizes the discussion regarding clinical dilemmas in local and regional testis cancer. We present cases that highlight the need for a coordinated approach to individualize care. Overarching themes include the importance of a multidisciplinary approach to testis cancer, willingness to involve a high-volume experienced center, and given that the oncological outcomes are excellent, a reminder that clinical decisions need to prioritize selecting a strategy with the least treatment-related morbidity when safe.

Utility of Serum miR-371a-3p in Predicting Relapse on Surveillance in Patients with Clinical Stage I Testicular Germ Cell Cancer.

BACKGROUND: Optimal management of clinical stage I (CSI) testicular cancer is controversial due to lack of robust prognostic factors; miRNA-371a-3p holds promise as a biomarker, although its clinical utility for identifying patients at risk of relapse is unknown. OBJECTIVE: To explore the association between serum miR-371a-3p and CSI surveillance relapse. DESIGN, SETTING, AND PARTICIPANTS: Serial banked sera from 151 CSI (101 seminomas and 50 nonseminomatous germ cell tumors [NSGCTs]) samples from our Princess Margaret active surveillance cohort were tested. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Using the ampTSmiR test, miR-371a-3p was assayed. Multivariate logistic regression was used to assess the association between postorchiectomy miRNA and relapse. RESULTS AND LIMITATIONS: Thirty-four (23%) patients relapsed. There was no association between postorchiectomy miR-371a-3p (2.43 vs 2.74, p = 0.31) or percent decline from before to after orchiectomy (95.8% vs 93.1%, p = 0.14) and relapse. After adjustment for clinical prognostic factors, there remained no association between postorchiectomy miR-371a-3p and relapse (seminoma: odds ratio [OR] 1.33, 95% confidence interval [CI] 0.87-2.02, p = 0.18; NSGCT: OR 0.45, 95% CI 0.21-1.00, p = 0.05). Postorchiectomy miR-371a-3p levels rose as the date of miRNA assessment approached relapse. At relapse, serum markers alpha-fetoprotein and human chorionic gonadotropin were normal in 62%; yet, miR-371a-3p was elevated in 32/34 (94.1%). The magnitude of miR-371a-3p elevation at relapse correlated with disease burden (N1/M0 122.5 vs N2-N3/M0: 521.1; p = 0.05). Limitations include small numbers of relapses and variable time points of serum collection. CONCLUSIONS: In our cohort of CSI testis cancer patients on surveillance, postorchiectomy miR-371a-3p levels were not associated with relapse, suggesting that miR-371a-3p may not be a useful biomarker for guiding adjuvant therapy. Our data suggest that miR-371a-3p holds potential as an early relapse marker and warrants a prospective study, as this may allow a window for less morbid relapse therapy. PATIENT SUMMARY: The promising novel blood biomarker for testis cancer miR-371a-3p may not provide information at testicle removal, but serial monitoring may lead to earlier detection of relapse.

Discrepancy in pathology reports upon second review of radical orchiectomy specimens for testicular germ cell tumors.

INTRODUCTION: We sought to evaluate the discrepancies between primary pathology report and second pathology review of radical orchiectomy (RO) specimens. METHODS: A retrospective review was performed of RO specimens from the Ontario Cancer Registry. All cases required both a primary pathology report and a second pathology review from another institution. Histopathological variables assessed included histological subtype and components of mixed germ cell tumor (GCT), pathological tumor (pT) stage, lymphovascular invasion (LVI), spermatic cord invasion, and surgical margin. RESULTS: Between 1994 and 2015, 5048 ROs were performed with 2719 (53.9%) seminoma and 2029 (40.2%) non-seminoma. Of these, 519 (10.3%) received a second pathology review. There was concordance between primary pathology report and second pathology review in 326 (62.8%) cases. The most common discrepancies involved a change in pT stage (n=148, 28.5%), with upstaging in 83 (16%) and downstaging in 65 (12.5%) cases relative to the original pT stage. The second most common discrepancy regarded the reporting of LVI (n=121, 23.3%), with 62 (11.9%) reporting presence of LVI when the primary pathology report did not. Other discrepancies included a change in the histological subtype in 28 (5.4%) cases and spermatic cord margin status in five (9.6%) cases. CONCLUSIONS: Only 10% of orchiectomy specimens underwent a second pathology review, with nearly 40% of reviews leading to a meaningful change in parameters. Such variation could lead to incorrect tumor staging, estimate of relapse risk, and inappropriate treatment decisions. Expert pathology review of RO specimens should be considered, as it has significant implications for decision-making.

A Canadian approach to the regionalization of testis cancer: A review.

At the Canadian Testis Cancer Workshop, the rationale and feasibility of regionalization of testis cancer care were discussed. The two-day workshop involved urologists, medical and radiation oncologists, pathologists, radiologists, physician's assistants, residents and fellows, and nurses, as well as patients and patient advocacy groups.This review summarizes the discussion and recommendations of one of the central topics of the workshop - the centralization of testis cancer in Canada. It was acknowledged that non-guideline-concordant care in testis cancer occurs frequently, in the range of 18-30%. The National Health Service in the U.K. stipulates various testis cancer care modalities be delivered through supra-regional network. All cases are reviewed at a multidisciplinary team meeting and aspects of care can be delivered locally through the network. In Germany, no such network exists, but an insurance-supported online second opinion network was developed that currently achieves expert case review in over 30% of cases. There are clear benefits to regionalization in terms of survival, treatment morbidity, and cost. There was agreement at the workshop that a structured pathway for diagnosis and treatment of testis cancer patients is required.Regionalization may be challenging in Canada because of geography; independent administration of healthcare by each province; physicians fearing loss of autonomy and revenue; patient unwillingness to travel long distances from home; and the inability of the larger centers to handle the ensuing increase in volume. We feel the first step is to identify the key performance indicators and quality metrics to track the quality of care received. After identifying these metrics, implementation of a "networks of excellence" model, similar to that seen in sarcoma care in Ontario, could be effective, coupled with increased use of health technology, such as virtual clinics and telemedicine.

Simultaneous Vs Sequential Retroperitoneal, Thoracic and Cervical Resection of Post Chemotherapy Residual Masses in Patients With Metastatic Nonseminomatous Germ Cell Tumors of the Testis.

OBJECTIVE: To compare a simultaneous vs sequential approach to residual post chemotherapy mass resections in metastatic testis cancer. METHODS: A retrospective review was performed of patients who underwent retroperitoneal and thoracic/cervical resection of post chemotherapy residual masses between 2002 and 2018. Group 1: "Simultaneous" (Combined Retroperitoneal and Thoracic/Cervical resections on the same date); Group 2: "Sequential" (Retroperitoneal and Thoracic/Cervical resections at separate dates). RESULTS: During the study period, 35 simultaneous and 17 sequential resections were performed. The median age at surgery was 28 years (Range 16-61). The median follow-up from last surgical procedure was 62.7 months (Range 0.4-194). Histology revealed teratoma in 38 (73.1%) patients, necrosis in 8 (15.4%) and viable tumor in 6 (11.5%). Discordant pathology findings between thoracic/cervical and abdominal resections were noted in 16 (30.8%) patients. No differences were observed between the simultaneous vs sequential groups in median operating time (585 minutes vs 545 minutes, P = .64), blood loss (1300 vs 1300 mls, P = .42), or length of stay (9 vs 11 days, P = .14). There was no difference between the 5-year (65.7% vs 68.6%) relapse-free survival between the 2 groups (P = .84) or the 5-year (88.6% vs 100%) overall and disease-specific survival (P = .25). CONCLUSION: Simultaneous resection of retroperitoneal and thoracic/cervical post chemotherapy metastases is a feasible in some patients. It requires multidisciplinary collaboration and a longer primary procedure.

The Prognostic Value of Neutrophil-to-Lymphocyte Ratio in Metastatic Testicular Cancer.

We investigated the prognostic utility of pre-chemotherapy neutrophil-to-lymphocyte ratio (NLR) in patients with metastatic germ cell tumors (GCTs) undergoing first-line chemotherapy. We utilized two institutional databases to analyze the pretreatment-derived NLR (dNLR). Predictive accuracy was evaluated using the Cox proportional hazard model adjusted for the international germ cell cancer collaborative group (IGCCCG) risk classification. Discriminatory accuracy was evaluated by determining the area under the receiver operating characteristic curve (AUROC). In total, 569 of 690 patients had available dNLR (IGCCCG: good, 64%; intermediate, 21%; poor, 16%). The 5-year and 10-year overall survivals (OSs) for good, intermediate, and poor risk groups were 96.2%, 92.8%, and 62.7% and 93.9%, 90.3%, and 62.7%, respectively. A dNLR of 2 provided the best discriminatory accuracy with an AUROC of 0.58 (95% CI: 0.52-0.65, p = 0.01) for progression-free survival (PFS), whereas for OS, a dNLR of 3 provided the best discriminatory accuracy with an AUROC of 0.62 (95% CI: 0.53-0.70, p < 0.01). A dNLR > 2 was associated with a hazard ratio (HR) of 1.99 (95% CI: 1.27-3.12, p < 0.01) for PFS, which lost its effect after adjustment for IGCCCG (HR: 1.44, 95% CI: 0.90-2.30, p = 0.13). For OS, a dNLR >3 was associated with an HR of 3.00 (95% CI: 1.79-5.01, p < 0.01), but lost its effect after adjustment for IGCCCG. Systemic inflammation plays a role in metastatic GCT, but its prognostic utility beyond established algorithms is limited. The general prognostic value of NLR can be seen across a number of tumors, although the consistency and magnitude of the effect differ according to cancer type, disease stage, and treatment received. We identified that an elevated NLR was associated with an adverse PFS and OS, but not independent of the IGCCCG risk classification. dNLRs >2 and >3 were associated with an adverse PFS and OS, respectively, in patients with metastatic GCT receiving first-line chemotherapy, but not independent of the IGCCCG risk classification.

Detection of Relapse by Low-dose Computed Tomography During Surveillance in Stage I Testicular Germ Cell Tumours.

BACKGROUND: Standard-dose computed tomography (SDCT) scans are associated with radiation exposure during stage I testicular cancer surveillance. OBJECTIVE: To evaluate low-dose CT (LDCT) for clinical use. DESIGN, SETTING, AND PARTICIPANTS: In this single-arm prospective study, patients on surveillance for stage I testicular germ cell tumour underwent SDCT and LDCT scans on their first visit after enrolment. The adequacy of LDCT image quality was assessed for subsequent use. Patients were followed with LDCT only and suspected relapse was confirmed by SDCT. OUTCOME MEASURES AND STATISTICAL ANALYSIS: We assessed whether initial LDCT scans were of sufficient quality for routine clinical use. We compared mean differences in nodal size at relapse between LDCT and SDCT using a one-sample paired t test. The relapse free-rate was calculated using the Kaplan-Meier method. RESULTS AND LIMITATIONS: Of 257 patients, one was excluded because of inadequate image quality. At median follow-up of 5.25 yr, 35 patients had relapsed, 33 with retroperitoneal lymphadenopathy. The 2- and 5-yr relapse-free rates were 89.5% and 85.3%, respectively. The mean size of retroperitoneal nodal relapse was 17.3 and 17.5mm on the short axis, 23.2 and 22.7mm on the long axis, and 26.1 and 26.7mm on craniocaudal length for LDCT and SDCT, respectively. The mean difference between LDCT and SDCT was 0.14mm (p=0.55) short axis, -0.54mm (p=0.092) long axis, and -0.51mm (p=0.086) length. A limitation was the lack of a control arm. CONCLUSIONS: LDCT image quality was adequate for clinical use, and retroperitoneal nodal relapse was detected with minimal differences seen between LD and SDCT. LDCT can be safely adopted and will decrease overall radiation exposure in stage I germ cell tumour surveillance. PATIENT SUMMARY: We studied the use of low-dose computed tomography scans for detecting testicular cancer recurrence in lymph nodes of the abdomen and pelvis and found that they were safe, effective and would potentially reduce overall X-ray exposure. This trial is registered at ClinicalTrials.gov as NCT03142802.

Treatment of Relapse of Clinical Stage I Nonseminomatous Germ Cell Tumors on Surveillance.

PURPOSE: Active surveillance (AS) for testicular nonseminomatous germ cell tumors (NSGCT) is widely used. Although there is no consensus for optimal treatment at relapse on surveillance, globally patients typically receive chemotherapy. We describe treatment of relapses in our non-risk-adapted NSGCT AS cohort and highlight selective use of primary retroperitoneal lymph node dissection (RPLND). METHODS: From December 1980 to December 2015, 580 patients with clinical stage I NSGCT were treated with AS, and 162 subsequently relapsed. First-line treatment was based on relapse site and extent. Logistic regression was used to explore factors associated with need for multimodal therapy on AS relapse. RESULTS: Median time to relapse was 7.4 months. The majority of relapses were confined to the retroperitoneum (66%). After relapse, first-line treatment was chemotherapy for 95 (58.6%) and RPLND for 62 (38.3%), and five patients (3.1%) underwent other therapy. In 103 (65.6%), only one modality of treatment was required: chemotherapy only in 58 of 95 (61%) and RPLND only in 45 of 62 (73%). Factors associated with multimodal relapse therapy were larger node size (odds ratio, 2.68; P = .045) in patients undergoing chemotherapy and elevated tumor markers (odds ratio, 6.05; P = .008) in patients undergoing RPLND. When RPLND was performed with normal markers, 82% required no further treatment. Second relapse occurred in 30 of 162 patients (18.5%). With median follow-up of 7.6 years, there were five deaths (3.1% of AS relapses, but 0.8% of whole AS cohort) from NSGCT or treatment complications. CONCLUSION: The retroperitoneum is the most common site of relapse in clinical stage I NSGCT on AS. Most are cured by single-modality treatment. RPLND should be considered for relapsed patients, especially those with disease limited to the retroperitoneum and normal markers, as an option to avoid chemotherapy.

Gene expression signatures prognostic for relapse in stage I testicular germ cell tumours.

OBJECTIVES: To identify differentially expressed genes between relapsed and non-relapsed clinical stage I testicular germ cell tumours (TGCTs). MATERIALS AND METHODS: We reviewed patients with clinical stage I non-seminoma and seminoma from an institutional database (2000-2012) who were managed by active surveillance. Patients with non-relapsed non-seminoma and non-relapsed seminoma were defined as being relapse-free after 2 and 3 years of surveillance, respectively. RNA extraction and gene expression analysis was performed on archival primary tumour samples and gene-set enrichment analysis (GSEA) was conducted in order to identify differentiating biological pathways. RESULTS: A total of 57 patients (relapsed non-seminoma, n = 12; relapsed seminoma, n =15; non-relapsed non-seminoma, n = 15; non-relapsed seminoma, n = 15) were identified, with a median (range) relapse time of 5.6 (2.5-18.1) and 19.3 (4.7-65.3) months in the relapsed non-seminoma and relapsed seminoma cohorts, respectively. A total of 1 039 differentially expressed genes were identified that separated relapsed and non-relapsed groups. In patients with relapse, GSEA revealed enrichment in pathways associated with differentiation, such as skeletal development (i.e. FGFR1, BMP4, GLI2, SPARC, COL2A1), tissue (i.e. BMP4, SPARC, COL13A1) and bone remodelling (i.e. CARTPT, GLI2, MGP). A discriminative gene expression profile between relapsed and non-relapsed cases was discovered when combining non-seminoma and seminoma samples using 10- and 30-probe signatures; however, this profile was not observed in the seminoma and non-seminoma cohorts individually. CONCLUSION: A discriminating signature for relapsed disease was identified for clinical stage I TGCT that we were not able to identify by histology alone. Further validation is required to determine if this signature provides independent prognostic information to standard pathological risk factors.

Serum miRNA Predicts Viable Disease after Chemotherapy in Patients with Testicular Nonseminoma Germ Cell Tumor.

PURPOSE: Retroperitoneal lymph node dissection is recommended for residual masses greater than 1 cm after chemotherapy of nonseminomatous germ cell tumors. Currently there is no reliable predictor of post-chemotherapy retroperitoneal lymph node dissection histology. Up to 50% of patients harbor necrosis/fibrosis only so that a potentially morbid surgery has limited therapeutic value. In this study we evaluated the ability of defined serum miRNAs to predict residual viable nonseminomatous germ cell tumors after chemotherapy. MATERIALS AND METHODS: Levels of serum miRNA, including miR-371a-3p, miR-373-3p and miR-367-3p, were measured using the ampTSmiR (amplification targeted serum miRNA) test in 82 patients, including 39 in cohort 1 and 43 in cohort 2, who were treated with orchiectomy, chemotherapy and post-chemotherapy retroperitoneal lymph node dissection. miRNA levels were compared to clinical characteristics and serum tumor markers, and correlated with the presence of viable germ cell tumor vs fibrosis/necrosis and teratoma. ROC analysis was done to determine miRNA discriminative capacity. RESULTS: miRNA levels were significantly associated with disease extent at chemotherapy and they decreased significantly after chemotherapy. Conventional serum tumor marker levels were uninformative after chemotherapy. However, after chemotherapy miRNA levels remained elevated in patients harboring viable germ cell tumor in post-chemotherapy retroperitoneal lymph node dissection specimens. miR-371a-3p demonstrated the highest discriminative capacity for viable germ cell tumors (AUC 0.874, 95% CI 0.774-0.974, p <0.0001). Using an adapted hypothetical cutoff of 3 cm or less for surgical intervention miR-371a-3p correctly stratified all patients with viable residual retroperitoneal germ cell tumors with 100% sensitivity (p = 0.02). CONCLUSIONS: Our study demonstrates for the first time the potential value of miR-371a-3p to predict viable germ cell tumors in residual masses after chemotherapy. Prospective studies are required to confirm clinical usefulness.

A New Model to Predict Benign Histology in Residual Retroperitoneal Masses After Chemotherapy in Nonseminoma.

BACKGROUND: Postchemotherapy retroperitoneal lymph node dissection (pcRPLND) is indicated in testicular cancer patients with normalised or plateaued serum tumour markers and residual retroperitoneal lesions >1cm. Challenges remain in predicting postchemotherapy residual mass (pcRM) histology, which may lead to unnecessary surgery. OBJECTIVE: To develop an accurate model to predict pcRM histology in patients with nonseminomatous germ cell tumours (NSGCTs). DESIGN, SETTING, AND PARTICIPANTS: A retrospective review of 335 patients undergoing pcRPLND for metastatic NSGCTs to develop a model to predict benign histology in retroperitoneal pcRM. Our model was compared with others and externally validated. INTERVENTION: Chemotherapy and pcRPLND. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Multivariable logistic regression to evaluate the presence of benign histology, and fractional polynomials to allow for a nonlinear association between continuous variables and the outcome. The final Princess Margaret model (PMM) was selected based on the number of variables used, reliability, and discriminative capacity to predict benign pcRM. RESULTS AND LIMITATIONS: PMM included the presence of teratoma in the orchiectomy, prechemotherapy α-fetoprotein, prechemotherapy mass size, and change in mass size during chemotherapy. Model specificity was 99.3%. Compared with Vergouwe et al's model, PMM had significantly better accuracy (C statistic 0.843 vs 0.783). PMM appropriately identified a larger number of patients for whom pcRPLND can safely be avoided (13.9% vs 0%). Validated in external cohorts, the model retained high discrimination (C statistic 0.88 and 0.80). Larger and prospective studies are needed to further validate this model. CONCLUSIONS: Our clinical model, externally validated, showed improved discriminative ability in predicting pcRM histology when compared with other models. The higher accuracy and reduced number of variables make this a novel and appealing model to use for patient counselling and treatment strategies. PATIENT SUMMARY: Princess Margaret model accurately predicted postchemotherapy benign histology. These results might have clinical impact by avoiding unnecessary retroperitoneal lymph node dissection and consequently changing the paradigm of advanced testicular cancer treatment.

Applying Radiomics to Predict Pathology of Postchemotherapy Retroperitoneal Nodal Masses in Germ Cell Tumors.

PURPOSE: After chemotherapy, approximately 50% of patients with metastatic testicular germ cell tumors (GCTs) who undergo retroperitoneal lymph node dissections (RPNLDs) for residual masses have fibrosis. Radiomics uses image processing techniques to extract quantitative textures/features from regions of interest (ROIs) to train a classifier that predicts outcomes. We hypothesized that radiomics would identify patients with a high likelihood of fibrosis who may avoid RPLND. PATIENTS AND METHODS: Patients with GCT who had an RPLND for nodal masses > 1 cm after first-line platinum chemotherapy were included. Preoperative contrast-enhanced axial computed tomography images of retroperitoneal ROIs were manually contoured. Radiomics features (n = 153) were used to train a radial basis function support vector machine classifier to discriminate between viable GCT/mature teratoma versus fibrosis. A nested 10-fold cross-validation protocol was used to determine classifier accuracy. Clinical variables/restricted size criteria were used to optimize the classifier. RESULTS: Seventy-seven patients with 102 ROIs were analyzed (GCT, 21; teratoma, 41; fibrosis, 40). The discriminative accuracy of radiomics to identify GCT/teratoma versus fibrosis was 72 ± 2.2% (area under the curve [AUC], 0.74 ± 0.028); sensitivity was 56.2 ± 15.0%, and specificity was 81.9 ± 9.0% ( P = .001). No major predictive differences were identified when data were restricted by varying maximal axial diameters (AUC range, 0.58 ± 0.05 to 0.74 ± 0.03). The prediction algorithm using clinical variables alone identified an AUC of 0.76. When these variables were added to the radiomics signature, the best performing classifier was identified when axial masses were limited to diameter < 2 cm (accuracy, 88.2 ± 4.4; AUC, 0.80 ± 0.05; P = .02). CONCLUSION: A predictive radiomics algorithm had a discriminative accuracy of 72% that improved to 88% when combined with clinical predictors. Additional independent validation is required to assess whether radiomics allows patients with a high predicted likelihood of fibrosis to avoid RPLND.

Impact of Granulocyte-colony Stimulating Factor on Bleomycin-induced Pneumonitis in Chemotherapy-treated Germ Cell Tumors.

OBJECTIVE: To examine the impact of granulocyte-colony stimulating factor (G-CSF) use on the incidence and severity of bleomycin-induced pneumonitis (BIP) in patients with germ cell tumor (GCT) receiving first-line chemotherapy. PATIENTS AND METHODS: Clinical data from our institutional GCT database was complemented by review of radiology, pharmacy, and medical records. All patients receiving first line chemotherapy between January 1, 2000 and December 31, 2010 were included. Patients receiving at least 1 dose of G-CSF were identified. BIP was graded using Common Terminology Criteria for Adverse Events criteria. Logistic regression was used to explore predictors for risk and severity of BIP. Statistical significance was defined as P < .05. RESULTS: Data on 212 patients with GCT treated with a bleomycin-containing chemotherapy regimen were available. The median age was 31 years. The median follow-up period was 36.7 months. BIP occurred in 73 patients (34%), a majority (n = 55) of which were asymptomatic events (Common Terminology Criteria for Adverse Events, grade 1). G-CSF use was not associated with increased risk of BIP in multivariable analyses (odds ratio, 1.60; P = .13), nor was it associated with increased severity of symptomatic BIP (on average 1.22 grades higher; P = .09). There was a non-statistically significant trend towards greater risk of BIP in patients that developed renal impairment during chemotherapy treatment (odds ratio, 2.56; P = .053). CONCLUSION: In patients with GCT receiving first line chemotherapy, G-CSF use is not associated with an increased risk of BIP. Furthermore, the use of G-CSF did not have any significant effect on the severity of BIP events. Clinicians are reminded to be vigilant of patients that develop renal impairment while undergoing chemotherapy treatment, given the greater risk of BIP.