Performance characteristics of 18F-fluciclovine positron emission tomography/computed tomography prior to retroperitoneal lymph node dissection

Introduction: We aimed to determine whether anti-1-amino-3-18F-fluorocyclobutane-1-carboxylic acid (18F-fluciclovine) positron emission tomography/computed tomography (PET/CT) can accurately detect residual non-seminomatous germ cell tumor (NSGCT) prior to retroperitoneal lymph node dissection (RPLND). There is no reliable way to differentiate between fibrosis/necrosis, teratoma, and viable germ cell tumor in patients receiving post-chemotherapy RPLND. Functional imaging, including 18F-fludeoxyglucose (18F-FDG) PET/CT, has been disappointing. Due to the need for better imaging modalities, our prospective, pilot study aims to investigate the accuracy of 18F-fluciclovine PET/CT in detecting residual tumor prior to RPLND. Methods: From March 2018 to May 2019, 10 eligible patients underwent preoperative 18F-fluciclovine PET/CT prior to undergoing bilateral, full-template RPLND or excision of mass (for one re-do RPLND) in a prospective, phase 2 study. Correlation between 18F-fluciclovine PET/CT and RPLND pathology were evaluated on a per-patient level. Results: A total of 10 patients (mean age 29±7.6 years) underwent 18F-fluciclovine PET/CT prior to surgery. Nine of 10 patients received chemotherapy prior to RPLND. Correlation between 18F-fluciclovine PET/CT and RPLND pathology was seen in 3/10 (30%) patients. Five of 10 patients (50%) with negative 18F-fluciclovine PET/CT were found to have residual disease/teratoma on RPLND. Compared to the reference standard of RPLND, 18F-fluciclovine PET/CT demonstrated 29% sensitivity and 33% specificity. No patients experienced any adverse events due to 18F-fluciclovine PET/CT. Conclusions: Despite a different mechanism of action from 18F-FDG, 18F-fluciclovine has low sensitivity and specificity for residual teratoma in the retroperitoneum.

Blood-based biomarkers of human papillomavirus-associated cancers: A systematic review and meta-analysis

BACKGROUND

Despite the significant societal burden of human papillomavirus (HPV)-associated cancers, clinical screening interventions for HPV-associated noncervical cancers are not available. Blood-based biomarkers may help close this gap in care.

METHODS

Five databases were searched, 5687 articles were identified, and 3631 unique candidate titles and abstracts were independently reviewed by 2 authors; 702 articles underwent a full-text review. Eligibility criteria included the assessment of a blood-based biomarker within a cohort or case-control study.

RESULTS

One hundred thirty-seven studies were included. Among all biomarkers assessed, HPV-16 E seropositivity and circulating HPV DNA were most significantly correlated with HPV-associated cancers in comparison with cancer-free controls. In most scenarios, HPV-16 E6 seropositivity varied nonsignificantly according to tumor type, specimen collection timing, and anatomic site (crude odds ratio [cOR] for p16+ or HPV+ oropharyngeal cancer [OPC], 133.10; 95% confidence interval [CI], 59.40-298.21; cOR for HPV-unspecified OPC, 25.41; 95% CI, 8.71-74.06; cOR for prediagnostic HPV-unspecified OPC, 59.00; 95% CI, 15.39-226.25; cOR for HPV-unspecified cervical cancer, 12.05; 95% CI, 3.23-44.97; cOR for HPV-unspecified anal cancer, 73.60; 95% CI, 19.68-275.33; cOR for HPV-unspecified penile cancer, 16.25; 95% CI, 2.83-93.48). Circulating HPV-16 DNA was a valid biomarker for cervical cancer (cOR, 15.72; 95% CI, 3.41-72.57). In 3 cervical cancer case-control studies, cases exhibited unique microRNA expression profiles in comparison with controls. Other assessed biomarker candidates were not valid.

CONCLUSIONS

HPV-16 E6 antibodies and circulating HPV-16 DNA are the most robustly analyzed and most promising blood-based biomarkers for HPV-associated cancers to date. Comparative validity analyses are warranted. Variations in tumor type-specific, high-risk HPV DNA prevalence according to anatomic site and world region highlight the need for biomarkers targeting more high-risk HPV types. Further investigation of blood-based microRNA expression profiling appears indicated.

Serum Small RNA Sequencing and miR-375 Assay Do Not Identify the Presence of Pure Teratoma at Postchemotherapy Retroperitoneal Lymph Node Dissection

Existing tumor markers for testicular germ cell tumor (TGCT) cannot detect the presence of pure teratoma. Serum miRNAs have strong performance detecting other subtypes of TGCT. Previous reports suggest high levels of miR-375 expression in teratoma tissue. The purpose of this study was to explore the role of serum miRNA, including miR-375, in detecting the presence of teratoma at postchemotherapy retroperitoneal lymph node dissection (PC-RPLND).

We prospectively collected presurgical serum from 40 TGCT patients undergoing PC-RPLND (21 with teratoma at RPLND and 19 with no evidence of disease). We examined the utility of serum miR-375-3p and miR-375-5p by quantitative polymerase chain reaction, and searched for other putative serum miRNAs with small RNA sequencing. The area under the receiver operating characteristic curve (AUC) and univariate analyses were utilized to evaluate test characteristics and predictors of teratoma.

Both serum miR-375-3p and miR-375-5p exhibited poor performance (miR-375-3p: 86% sensitivity, 32% specificity, AUC: 0.506; miR-375-5p: 55% sensitivity, 67% specificity, AUC: 0.556). Teratoma at orchiectomy was the only predictor of PC-RPLND teratoma. Small RNA sequencing identified three potentially discriminatory miRNAs, but further validation demonstrated no utility. Our results confirm prior reports that serum miR-375 cannot predict teratoma, and suggest that there may not exist a predictive serum miRNA for teratoma.

Patient summary

We found that serum miR-375 cannot detect the presence of teratoma at postchemotherapy retroperitoneal lymph node dissection (PC-RPLND). We are also unable to find any other serum miRNAs predictive of pure teratoma at PC-RPLND. Hence, the lack of a reliable circulating marker of teratoma remains a critical clinical need.

Gleason Grade Group Concordance between Preoperative Targeted Biopsy and Radical Prostatectomy Histopathologic Analysis: A Comparison Between In-Bore MRI-guided and MRI-Transrectal US Fusion Prostate Biopsies

Purpose

To determine and compare rates of grade group (GG) discrepancies between different targeted biopsy techniques (in-bore vs fusion) after propensity score weighting using whole-mount radical prostatectomy (RP) histopathologic analysis as the reference standard.

Materials and Methods

This retrospective study evaluated men who underwent targeted (fusion or in-bore) biopsy between April 2017 and January 2019 followed by prostatectomy. The primary endpoint of the study was a change in GG from biopsy to RP at a patient level. For downgrade and upgrade analysis, men with biopsy GG1 (downgrade not possible) and GG5 (upgrade not possible) were excluded, respectively. GG upgrade, downgrade, and concordance rates of each targeting approach were compared using propensity score weighting and logistic regression with inverse probability of treatment weighting. Significance level was set at .05. Index lesion GG on RP specimen served as the reference standard.

Results

A total of 191 men (90 in the in-bore [mean age, 63 years ± 7 (standard deviation)] and 101 in the fusion biopsy group [mean age, 65 years ± 7]) were eligible and included. Fewer GG upgrades were noted in the in-bore biopsy group (14%; 12 of 85) compared with the fusion plus systematic biopsy group (30%; 28 of 93) (P = .012). The incidence of GG downgrade in the in-bore group (25%; 21 of 84) was higher than in the fusion group (17%; 16 of 93); however, the difference was not statistically significant (P = .2). Of the 77 men misclassified by both biopsy techniques, the majority (56%, n = 43) had a change in GG of 2 to 3 or 3 to 2.

Conclusion

Superior sampling accuracy with MRI-guided in-bore biopsies offers a lower incidence of GG upgrades compared with MRI-transrectal US fusion biopsies upon RP.Keywords: Biopsy/Needle Aspiration, MR-Imaging, Oncology, Pathology, Prostate Supplemental material is available for this article.© RSNA, 2021.

Validation of testicular germ cell tumor (GCT) staging in nationwide cancer registries

383

Background: Nationwide cancer registries such as the National Cancer Database (NCDB) and Surveillance, Epidemiology, and End Results (SEER) rely on accurate data from institutional tumor registries to formulate hypotheses and report outcomes and treatment patterns for patients with cancer. We evaluated the accuracy of our institutional registry for testicular germ cell tumors (GCT) by comparing data abstracted by urologists with data abstracted by our tumor registry. Methods: We performed a retrospective review of patients receiving initial diagnosis and treatment for testicular cancer at our hospital system from 2005-2016. We reviewed registrar coding for American Joint Committee on Cancer clinical staging, overall composite stage grouping, and first-line treatment and compared it with urologist-reviewed staging at the time of diagnosis. Results: Paired staging from registry and urologist was available for 80 patients. T, N, M, and S-staging were accurate for 90%, 81%, 94%, and 54% of records, respectively. Composite staging and first-line treatment were concordant for 39% and 90% of patients, respectively. A separate review of 33 Stage IS patients per registry for composite staging revealed only 15% concordance. Conclusions: We identified significant inconsistencies with data abstracted by our institutional tumor registry for patients with testicular cancer, most notably with regards to S and composite stage. An educational intervention to improve abstraction by registry led to increased concordance. Assuming similar discrepancies may exist at other institutions and for other cancer types, caution should be used when interpreting NCDB and SEER cancer staging data. This sheds light on the need for improved clarification of staging guidelines, dynamic institutional internal auditing, and training reform within cancer registries.

Sarcopenia prior to and following chemotherapy to predict morbidity in patients undergoing post-chemotherapy retroperitoneal lymphadenectomy (PC-RPLND)

381

Background: Patients undergoing post-chemotherapy retroperitoneal lymphadenectomy (PC-RPLND) are subject to variable but substantial risks. Unlike those patients undergoing other extirpative GU surgeries, patients undergoing PC-RPLND are usually younger and possess fewer co-morbidities. Despite this, the burden of metastatic disease and the effects of pre-operative chemotherapy may leave patients poorly conditioned prior to undergoing surgery. Sarcopenia has previously been demonstrated to predict adverse clinical outcomes in a variety of abdominal surgeries. We hypothesized that sarcopenia would be similarly predictive of morbidity and mortality in patients undergoing PC-RPLND. Methods: The records of all patients undergoing post-chemotherapy retroperitoneal lymphadenectomy for the treatment of metastatic germ cell tumors at both a public safety net hospital and an academic tertiary medical center were reviewed. Sarcopenia was assessed by measuring cross sectional area of the psoas muscle at the middle of the third lumbar vertebral body on pre-chemotherapy and preoperative computerized tomography. Psoas Muscle Index (PMI) was calculated by adjusting total psoas area for patient height (cm2/m2). Univariate and multivariate analysis was performed to assess the predictive value of sarcopenia for morbidity and mortality following PC-RPLND. Results: 90 patients underwent PC-RPLND from the year 2006-2019, of whom 81 patients had both pre-chemo and preoperative cross sectional imaging available. Prior to chemotherapy the mean PMI for this cohort was 7.32 cm2/m2, and this did not significantly change following chemotherapy mean PMI = 7.06 cm2/m2 (p = 0.44). Lower PMI both prior to (p = 0.05) and following chemotherapy (p = 0.03) were predictive of a higher risk of post-operative complication. There was a trend towards longer hospital length of stay in patients with more significant sarcopenia, however this was not clinically significant (p = 0.09). Conclusions: Sarcopenia was predictive of morbidity in patients undergoing PC-RPLND. Although sarcopenia did worsen following chemotherapy this was not statistically significant. Further assessment of sarcopenia and pre-operative nutritional status in this population may provide opportunities to reduce morbidity following PC-RPLND.

SEMS trial: Result of a prospective, multi-institutional phase II clinical trial of surgery in early metastatic seminoma

375

Background: Chemotherapy or radiotherapy are standard treatments for stage II seminoma, though they are associated with significant long-term treatment-related toxicities. Retroperitoneal lymph node dissection (RPLND) is an established treatment for testicular germ cell tumors but little data exists on its efficacy as a front-line treatment in early metastatic (stage II) seminoma. This is a single-arm, multi-institutional (NCT02537548), phase II study of retroperitoneal lymph node dissection (RLND) as first-line treatment for testicular seminoma with isolated retroperitoneal disease. Methods: Twelve sites in the United States and Canada prospectively enrolled patients (16 years of age) with testicular seminoma and isolated retroperitoneal lymphadenopathy between 1-3 cm in size. Patients were excluded if they received prior therapy (except orchiectomy) for testicular cancer. Open, modified-template RPLND was performed by qualified surgeons with a primary endpoint of 2-year recurrence-free survival. Data on complication rates (short and long-term), pathologic up/downstaging, recurrence patterns, adjuvant therapies, and treatment-free survival were assessed. Results: A total of 55 patients were enrolled and underwent RPLND. Fourteen patients had initial stage I disease who developed isolated retroperitoneal relapse while 41 patients had clinical stage IIA-B at presentation. With a median follow-up of 24 months (8-52 months), there were a total of 10 recurrences. The overall recurrence rate was 18% with a median time to recurrence of 8 months. Of the recurrences, 8 underwent chemotherapy (6 BEP X 3, 1 EP X 4, 1 carbo/etoposide) and 2 underwent additional surgery. The two-year recurrence free survival was 87% and the overall survival was 100%. There were 7 (13%) patients who experienced short-term complications within 1 year of RPLND. Of these, 5 (9%) were classified as Clavien Dindo I-II and 2 (3.6%) were classified as Clavien Dindo III. No patients have reported long-term complications. Conclusions: This trial establishes RPLND as a therapeutic option as a first-line treatment in early metastatic seminoma. The surgery offers cancer control rates similar to those seen in non-seminomatous germ cell tumors. Clinical trial information: NCT02537548.

Clinical utility of the AJCC eighth edition pT1 subclassification and impact on practice patterns in stage I seminoma

377

Background: The American Joint Committee on Cancer 8th edition staging guidelines for testicular cancer established a 3 cm cutoff to subclassify stage T1 seminomas (<3 cm = pT1a and ≥3 cm = pT1b). The efficacy of this cutoff in predicting metastatic disease and impact on treatment patterns has not been studied. Methods: We retrospectively reviewed patients with pT1 testicular seminoma in the National Cancer Database from 2004-2016. Receiver operating curves (ROC) were used to determine the efficacy of the 3 cm tumor cutoff in identifying metastatic disease, and multivariable regression was used to compute the effect of tumor size on the rate of adjuvant therapy among stage I patients. Results: 10,134 patients with pT1 seminoma were evaluated. The current size cutoff of 3 cm for subclassification did not exhibit high discrimination in identifying metastatic disease (area under ROC: 0.546). Surveillance has grown as the preferred treatment after orchiectomy – 32.1% in 2004 to 81.2% in 2015. However, the rate of adjuvant therapy for pT1, stage I seminomas associated positively with tumor size even with adjustment for year of diagnosis. For tumors above 3 cm, the odds ratio stabilized around 1.9. By using the 3cm cutoff to guide adjuvant therapy, up to 85% of T1b patients may be overtreated. Conclusions: The 3 cm cutoff for subclassification of stage I seminoma does not predict metastatic recurrence but is associated with increased receipt of adjuvant therapy. A 3 cm cutoff and the pT1a/b classification may therefore contribute to overtreatment in many young patients with a long life expectancy for whom minimizing adverse effects should be prioritized.

Pre-orchiectomy serum tumor markers as a predictor of recurrence in stage I germ cell tumors

389

Background: Organ confined (stage IA/IB) testicular cancer has a high cure rate regardless of initial treatment modality, making it important to weigh the toxicities of treatment against potential benefits. While many clinicians routinely obtain serum tumor markers (STMs) prior to radical orchiectomy, their role in predicting recurrence in stage IA and IB testicular cancer has not been studied. Methods: A multi-institutional database of stage I testicular cancer patients diagnosed between 2006 and 2018 was created. Univariate and multivariate regression models were created to understand which factors predict recurrence. Recurrence analyses using Kaplan-Meier curves for elevated and normal pre-orchiectomy STMs were also generated. Results: 150 patients met the study criteria, of whom 16 (11%) relapsed (Table). 9 (56%) patients with recurrence had elevated pre-orchiectomy STMs, and 7 (44%) had normal pre-orchiectomy STMs. Similarly, 75 patients (56%) without relapse had elevated pre-orchiectomy STMs. Of 9 patients with elevated pre-orchiectomy STMs, 6 (67%) had normal STMs at recurrence; of 7 with normal pre-orchiectomy STMs, 4 patients (57%) had elevated STMs at recurrence. On Kaplan-Meier analysis, no association between level of pre-orchiectomy STMs and recurrence free survival was observed. Conclusions: Pre-orchiectomy STMs were not independently associated with recurrence in stage I testis cancer. Interestingly, there was also no association between positivity of pre-orchiectomy STMs and whether or not STMs were elevated at recurrence. These findings support the continued use of standard-of-care imaging and STMs in surveillance of stage IA/IB testicular cancer patients regardless of pre-orchiectomy STMs. [Table: see text]

Real-world application of pre-orchiectomy miR-371a-3p test in testicular germ cell tumor (GCT) management

387

Background: Current serum tumor markers (STMs) for testicular germ cell tumor (GCT) are limited by low sensitivity. Growing evidence supports the use of circulating miR-371a-3p as a superior marker for malignant (viable) GCT management. We evaluated the real-world application of serum miR-371a-3p levels in detecting viable GCT among patients undergoing partial or radical orchiectomy. Methods: Serum samples were collected from 69 consecutive patients pre-orchiectomy. Performance characteristics of serum miR-371a-3p were compared with conventional STMs (AFP/β-hCG/LDH) between viable GCT patients and those without viable GCT on orchiectomy pathology. Relative miR-371a-3p levels were correlated with clinical course. Kruskal-Wallis test and linear and ordinal regression models were used for analysis. Results: For detecting viable GCT, combined conventional STMs had a specificity of 100%, sensitivity of 58%, and area under the curve (AUC) of 0.79 (Table). The miR-371a-3p test showed a specificity of 100%, sensitivity of 93%, and AUC of 0.978. Median relative expression of miR-371a-3p in viable GCT patients was >6,800-fold higher than in patients lacking viable GCT. MiR-371a-3p levels correlated with composite stage (CS) (p=0.006), and, among CS I patients, independently associated with embryonal carcinoma percentage (p=0.0012) and tumor diameter (p<0.0001). Six patients received orchiectomy after chemotherapy and were correctly predicted to have presence or absence of viable GCT by the miR-371a-3p test. Conclusions: If validated, the miR-371a-3p test can be used in conjunction with conventional STMs to aid clinical decision-making. A positive miR-371a-3p test in patients after preoperative chemotherapy or with solitary testes could potentially guide subsequent orchiectomy or observation. [Table: see text]

Phase II trial of stereotactic ablative radiation (SAbR) for oligometastatic kidney cancer

311

Background: Stereotactic ablative radiotherapy (SAbR) is a promising treatment option for selected oligometastatic renal cell carcinoma (RCC) patients that can provide longitudinal disease control while preserving quality of life. Retrospective data have shown a local control (LC) rate greater than 90% and longitudinal disease control of over a year without systemic therapy. However, prospective validation of SAbR for oligometastatic RCC is lacking. In this prospective phase II single arm trial, we evaluated the impact of SAbR on freedom from systemic therapy (FFST). Methods: Treatment naïve patients with RCC confirmed by pathology and radiographic evidence of three or fewer extracranial metastases received SAbR with curative intent to all measurable sites of disease. Follow-up included radiographic imaging at three-month intervals to assess disease control. The primary endpoint was FFST defined as time from SAbR to the initiation of systemic therapy. Secondary endpoints included LC, modified progression-free survival (mPFS) (time from first SAbR to progression not amenable to further SAbR), PFS on subsequent systemic therapy, cancer-specific survival (CSS), overall survival (OS), toxicity and health-related quality of life (QOL) indices as measured with EQ-5D-5L and FACT-G. A Wilcoxon signed-rank test was used to evaluate the QOL indices. Results: The trial completed accrual with the enrollment of 23 patients who received SAbR to a total of 38 sites. At a median follow-up of 12 months (interquartile range 1.8-16), 1-year FFST was 87% (95% CI: 56%-96%). The 1-year mPFS was 79% (95% CI:49%-93%), while the median mPFS has not yet been reached. Three patients had disease progression at individual time points of 3.5, 4.0, and 12 months. One of these patients developed brain metastases that were controlled with gamma knife radiosurgery without initiating systemic therapy. The LC, CSS, and OS were 100% (38/38), 100% (23/23), and 95% (22/23), respectively. When compared to baseline, no significant decline in QOL was detected. Three patients experienced treatment-related grade 1 toxicity; no ≥grade 2 toxicities were reported. One patient died of an unrelated cause. Conclusions: SAbR is a safe and effective treatment for oligometastatic RCC that can provide longitudinal disease control and preserve quality of life. These data support further evaluation of SAbR for oligometastatic RCC in a randomized study. Clinical trial information: NCT02956798 .

Magnetic Resonance Imaging Radiomics Analyses for Prediction of High-Grade Histology and Necrosis in Clear Cell Renal Cell Carcinoma: Preliminary Experience

INTRODUCTION

Percutaneous renal mass biopsy results can accurately diagnose clear cell renal cell carcinoma (ccRCC); however, their reliability to determine nuclear grade in larger, heterogeneous tumors is limited. We assessed the ability of radiomics analyses of magnetic resonance imaging (MRI) to predict high-grade (HG) histology in ccRCC.

PATIENTS AND METHODS

Seventy patients with a renal mass underwent 3 T MRI before surgery between August 2012 and August 2017. Tumor length, first-order statistics, and Haralick texture features were calculated on T2-weighted and dynamic contrast-enhanced (DCE) MRI after manual tumor segmentation. After a variable clustering algorithm was applied, tumor length, washout, and all cluster features were evaluated univariably by receiver operating characteristic curves. Three logistic regression models were constructed to assess the predictability of HG ccRCC and then cross-validated.

RESULTS

At univariate analysis, area under the curve values of length, and DCE texture cluster 1 and cluster 3 for diagnosis of HG ccRCC were 0.7 (95% confidence interval [CI], 0.58-0.82, false discovery rate P = .008), 0.72 (95% CI, 0.59-0.84, false discovery rate P = .004), and 0.75 (95% CI, 0.63-0.87, false discovery rate P = .0009), respectively. At multivariable analysis, area under the curve for model 1 (tumor length only), model 2 (length + DCE clusters 3 and 4), and model 3 (DCE cluster 1 and 3) for diagnosis of HG ccRCC were 0.67 (95% CI, 0.54-0.79), 0.82 (95% CI, 0.71-0.92), and 0.81 (95% CI, 0.70-0.91), respectively.

CONCLUSION

Radiomics analysis of MRI images was superior to tumor size for the prediction of HG histology in ccRCC in our cohort.

OncoTree: A Cancer Classification System for Precision Oncology

PURPOSE

Cancer classification is foundational for patient care and oncology research. Systems such as International Classification of Diseases for Oncology (ICD-O), Systematized Nomenclature of Medicine Clinical Terms (SNOMED-CT), and National Cancer Institute Thesaurus (NCIt) provide large sets of cancer classification terminologies but they lack a dynamic modernized cancer classification platform that addresses the fast-evolving needs in clinical reporting of genomic sequencing results and associated oncology research.

METHODS

To meet these needs, we have developed OncoTree, an open-source cancer classification system. It is maintained by a cross-institutional committee of oncologists, pathologists, scientists, and engineers, accessible via an open-source Web user interface and an application programming interface.

RESULTS

OncoTree currently includes 868 tumor types across 32 organ sites. OncoTree has been adopted as the tumor classification system for American Association for Cancer Research (AACR) Project Genomics Evidence Neoplasia Information Exchange (GENIE), a large genomic and clinical data-sharing consortium, and for clinical molecular testing efforts at Memorial Sloan Kettering Cancer Center and Dana-Farber Cancer Institute. It is also used by precision oncology tools such as OncoKB and cBioPortal for Cancer Genomics.

CONCLUSION

OncoTree is a dynamic and flexible community-driven cancer classification platform encompassing rare and common cancers that provides clinically relevant and appropriately granular cancer classification for clinical decision support systems and oncology research.

Clinical utility of the AJCC 8th edition pT1 subclassification and impact on practice patterns in stage I seminoma

BACKGROUND

The American Joint Committee on Cancer 8^th edition staging guidelines for testicular cancer established a 3 cm cutoff to subclassify stage T1 seminomas (<3 cm = pT1a and ≥3 cm = pT1b). The efficacy of this cutoff in predicting metastatic disease and impact on treatment patterns have not been studied.

METHODS

We retrospectively reviewed patients with pT1 testicular seminoma in the National Cancer Database from 2004 to 2016. Receiver operating curves were used to determine the efficacy of the 3 cm tumor cutoff in identifying metastatic disease, and multivariable regression was used to compute the effect of tumor size on the rate of adjuvant therapy among Stage I patients.

RESULTS

A total of 10,134 patients with pT1 seminoma were evaluated. The current size cutoff of 3 cm for subclassification did not exhibit high discrimination in identifying metastatic disease (area under receiver operating curve: 0.546). Surveillance has grown as the preferred treatment after orchiectomy -32.1% in 2004 to 81.2% in 2015. However, the rate of adjuvant therapy for pT1, Stage I seminomas associated positively with tumor size even with adjustment for year of diagnosis. For tumors above 3 cm, the odds ratio stabilized around 1.9. By using the 3 cm cutoff to guide adjuvant therapy, up to 85% of T1b patients may be overtreated.

CONCLUSION

The 3 cm cutoff for subclassification of Stage I seminoma does not predict metastatic recurrence but is associated with increased receipt of adjuvant therapy. A 3 cm cutoff and the pT1a/b classification may therefore contribute to overtreatment in many young patients with a long life expectancy for whom minimizing adverse effects should be prioritized.

Pathologic stage as a surrogate for oncologic outcomes after receipt of neoadjuvant chemotherapy for high-grade upper tract urothelial carcinoma

OBJECTIVE

Whether pathologic stage at radical nephroureterectomy (RNU) can serve as an appropriate surrogate for oncologic outcomes in patients with high-grade (HG) upper tract urothelial carcinoma (UTUC) treated with neoadjuvant chemotherapy (NAC) is not defined. We sought to determine whether patients who achieve pathologically non-muscle-invasive (ypT0, ypTa, ypT1, ypTis) HG UTUC after receipt of NAC exhibit oncologic outcomes comparable to those who are inherently low stage without chemotherapy.

METHODS

We identified 647 UTUC patients who underwent RNU among 3 institutions from 1993to2016. Patients with low or unknown grade, pathologic muscle invasion, or receipt of adjuvant chemotherapy were excluded. We compared clinicopathologic data and oncologic outcomes between pT0-1 and ypT0-1 patients. Kaplan-Meier analysis was used to assess overall (OS), cancer-specific (CSS), and systemic recurrence-free (RFS) survival. Predictors of these endpoints were identified using Cox regression.

RESULTS

234 (43 ypT0-1, 191 pT0-1) patients with HG UTUC were included. Two patients exhibited pathologic complete response after NAC. OS (P = 0.055), CSS (P = 0.152), and RFS (P = 0.098) were similar between ypT0-1 and pT0-1 patients. Predictors of worse outcomes included African-American race (RFS, CSS, and OS), Charlson score (OS), and systemic recurrence (OS and CSS).

CONCLUSIONS

Patients with HG UTUC who achieve ypT0-1 stage after NAC exhibit favorable oncologic outcomes comparable to those inherently non-muscle-invasive who do not receive chemotherapy. Improvements in clinical staging will play an important role in better defining candidacy for NAC in treating HG UTUC while minimizing overtreatment. Furthermore, pathologic stage may serve as an appropriate early surrogate for oncologic endpoints in designing clinical trials.

Impact of circulating microRNA test (miRNA-371a-3p) on appropriateness of treatment and cost outcomes in patients with Stage I non-seminomatous germ cell tumours

OBJECTIVES

To determine whether utilisation of a serum microRNA (miRNA) test could improve treatment appropriateness and cost-effectiveness for patients with Stage I non-seminomatous germ cell tumours (NSGCTs).

PATIENTS AND METHODS

A decision tree model was built to investigate treatment course, clinical and cost outcomes for patients with Stage IA (T1N0M0S0) and IB (T2-4N0M0S0) NSGCT. The model compared outcomes and cost of standard approach using histopathology, conventional serum tumour markers and radiographic staging (standard model) to a miRNA-based approach using the standard model + post-orchidectomy serum miR-371a-3p (marker model). Probabilities of expected treatment and outcomes were based on presence/absence of cancer upon entering into the model. Overtreatment was defined as adjuvant chemotherapy or primary retroperitoneal lymph node dissection in a patient without cancer. Undertreatment was defined as initial surveillance for a patient with cancer.

RESULTS

Utilising the miRNA marker-based approach, 26% of patients avoid overtreatment and 8% avoid undertreatment in Stage IA NSGCT; 27% avoid overtreatment and 23% avoid undertreatment in Stage IB disease. Appropriate treatment decision-making increased from 65% to 94% and 50% to 92% for Stage IA and IB, respectively. The miRNA-based approach remained cost-effective over a wide range of performance characteristics with savings of ~$1400 (American dollars)/patient for both Stage IA and IB disease.

CONCLUSION

A miRNA-based approach may potentially select patients with Stage I NSGCT for correct treatment in a cost-effective manner. Identification of residual teratoma-only remains an issue. Prospective studies are necessary to validate these findings.

Robotic Nephroureterectomy vs Laparoscopic Nephroureterectomy: Increased Utilization, Rates of Lymphadenectomy, Decreased Morbidity Robotically

Introduction and Objective: Robotic radical nephroureterectomy (RRNU) may offer advantages over laparoscopic radical nephroureterectomy (LRNU). The purpose of this study is to evaluate the overall survival (OS) of patients with upper tract urothelial carcinoma (UTUC) who underwent RRNU vs LRNU and identify factors that account for differences. Methods: The National Cancer Database was queried from 2010 to 2016 for patients with American Joint Committee on Cancer 6th/7th edition Stage I/II/III UTUC. Kaplan-Meier analysis compared LRNU and RRNU OS. Univariate analysis detected differences between the groups. Cox regression determined factors associated with mortality rate. Logistic regression identified predictors of a lymph node dissection (LND) and 90-day mortality rate. Results: A total of 2631 patients met the criteria, 1129 of whom underwent RRNU and 1502 LRNU, with a follow-up of 33 and 35 months, respectively (p = 0.063). RRNU had a median OS of 71.1 vs 62.6 months (p = 0.033). LRNU patients were older (72.7 vs 71.4, p < 0.001) and had no differences in comorbidities, pathologic T stage, or grade. The LRNU cohort was less likely to undergo LND (19% vs 35%, p < 0.001) and had a lower median lymph node yield (3 vs 4, p < 0.001). LRNU patients more likely underwent conversion to an open procedure, had longer hospital stays, and higher 30- and 90-day mortality rates. LRNU was independently associated with mortality rate (p = 0.030). Age, grade, positive margins, pT/pN stage were associated with mortality rate. Younger age, RRNU, surgery at an academic center, and neoadjuvant chemotherapy predicted an LND. Conclusions: RRNU demonstrated increased rates of LND and may offer a short-term morbidity benefit to LRNU. Survival differences may be due to improved characterization of disease through LND.

Considerations When Treating Patients with Good-risk Germ Cell Tumors

Three cycles of bleomycin, etoposide, and cisplatin or four cycles of etoposide and cisplatin are options for patients with good-risk germ cell tumors. Despite no significant differences in clinical outcomes in a randomized trial, studies suggest variable impact on postchemotherapy retroperitoneal lymph node dissection histology, which may help inform treatment decisions.

Perioperative outcomes and cost of robotic vs open simple prostatectomy in the modern robotic era: results from the National Inpatient Sample

OBJECTIVES

To perform a comparative analysis of perioperative outcomes and hospitalisation cost between open (OSP) and robot-assisted simple prostatectomy (RASP) for treatment of benign prostatic hyperplasia (BPH) using the National Inpatient Sample (NIS) in the contemporary robotic era.

MATERIALS AND METHODS

The NIS was queried for cases of OSP and RASP for the treatment of BPH between 2013 and 2016. Perioperative complications, unadjusted hospital cost and length of stay (LOS) were compared between RASP and OSP. Smoothed linear regression curves comparing hospitalisation cost by increasing LOS was stratified by surgical approach to identify point of cost equivalency between RASP and OSP. Multivariable linear regression analysis was used to construct a hospitalisation cost model to examine the contribution of the robotic approach and LOS to hospitalisation cost.

RESULTS

The total analytical cohort included 2551 OSP and 704 RASP procedures. Patients undergoing RASP were younger, at a median (interquartile range [IQR]) age of 68 (63-73) vs 71 (65-77) years, and with less comorbidity (76.8% vs 86.5%, P < 0.01). RASP was associated with fewer total complications (11.1% vs 29.2%, P < 0.01) and a greater likelihood of routine discharge to home rather than another facility (88.9% vs 76.7%, P < 0.01). While LOS was shorter with RASP (median [IQR], 2 [1-3] vs 4 [3-6] days, P < 0.01), total unadjusted hospitalisation cost (in United States dollars) was greater (median [IQR], $10 855 [$7965-$15 675] vs $13 467 [$10 572-$17 722], P < 0.01). Presence of any complication increased both LOS and hospitalisation cost (P < 0.01). Linear regression modelling determined the point of cost equivalence between RASP staying a median of 2 days was an OSP case staying between 5 and 6 days. On multivariable regression analysis, the robotic approach contributed an additional $6175 (P < 0.01) to the cost model, whereas each additional day of hospitalisation contributed $1687 (P < 0.01), suggesting LOS would need to be 3-4 days shorter with RASP to offset surgical costs of the robot.

CONCLUSIONS

While RASP appears to have significantly better perioperative complication rates with shorter LOS and likely discharge to home, total hospitalisation cost remained greater, likely related to upfront operative costs. While this retrospective study is limited by selection bias for patients undergoing RASP, the benefits of improved convalescence, discharge to home, and lower rate of perioperative complications appear to justify performance of RASP in an experienced pelvic robotic centre despite relatively greater hospitalisation cost if referral to an experienced holmium laser enucleation of the prostate centre is not feasible.