Gemcitabine and cisplatin plus nivolumab as organ-sparing treatment for muscle-invasive bladder cancer: a phase 2 trial

Cystectomy is a standard treatment for muscle-invasive bladder cancer (MIBC), but it is life-altering. We initiated a phase 2 study in which patients with MIBC received four cycles of gemcitabine, cisplatin, plus nivolumab followed by clinical restaging. Patients achieving a clinical complete response (cCR) could proceed without cystectomy. The co-primary objectives were to assess the cCR rate and the positive predictive value of cCR for a composite outcome: 2-year metastasis-free survival in patients forgoing immediate cystectomy or Collapse

Key Words

• phase ii trials
• translational research
• bladder cancer
• cancer immunotherapy
• chemotherapy

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MESH Headings

• Humans
• Antineoplastic Combined Chemotherapy Protocols/therapeutic use
• Cisplatin/therapeutic use
• Deoxycytidine/therapeutic use
• Disease-Free Survival
• Gemcitabine
• Muscles
• Neoadjuvant Therapy
• Neoplasm Invasiveness
• Nivolumab/therapeutic use
• Urinary Bladder Neoplasms/drug therapy
• Urinary Bladder Neoplasms/pathology
• Xeroderma Pigmentosum Group D Protein

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Grants

• U24 CA224319 NCI NIH HHS
• U01 DK124165 NIDDK NIH HHS
• U24 CA224316 NCI NIH HHS
• U24 CA224285 NCI NIH HHS
• T32 CA078207 NCI NIH HHS
• P30 CA196521 NCI NIH HHS
• U24 CA224331 NCI NIH HHS
• R01 CA249175 NCI NIH HHS
• V Foundation for Cancer Research (V Foundation)
• Bristol-Myers Squibb (Bristol-Myers Squibb Company)
• U.S. Department of Health & Human Services | NIH | National Cancer Institute (NCI)
• Foundation for the National Institutes of Health (FNIH)/Partnership for Accelerating Cancer Therapies (PACT)

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Comparing pretest video genetic education for prostate cancer patients: Do patients need assistance?

5061

Background: Expanded germline genetic testing recommendations for individuals with prostate cancer (PCa) have resulted in increased demand for pre-test genetic education. As a result, alternative service delivery models in genetic counseling (GC) have been suggested. Previous research has shown no difference in genetic testing uptake when video genetic education (VGE) is used rather than face-to-face counseling. However, data is limited when evaluating how VGE is delivered to patients. This study aimed to evaluate the impact of pre-test VGE on genetic testing uptake when facilitated by a GC assistant or self-completed by the patient. Methods: PCa patients referred for GC were contacted for pre-test VGE. Patients were randomized to undergo VGE with a GC assistant via Zoom (assistant-led) or perform VGE on their own via email instructions (patient-led). Assistant-led VGE was scheduled via standard of care, and patient-led VGE involved electronic and phone contact. In both arms, pre-test VGE included administrating family history collection via electronic software and viewing of informational genetics video. VGE completion and genetic testing uptake was the primary outcome measured for all participants. Initial pilot data was presented previously. This analysis represents the entire study period outcome. Data analysis used t-test, Fisher’s exact and chi square. Results: From 10/1/2020-12/31/2021, 266 PCa patients were referred. In total, 254 were randomized, with 130 in the assistant-led intervention and 124 randomized to the patient-led arm. Technological limitations, loss to follow up, and procedural withdrawals resulted in 41 (31.5%) patients in the assistant-led arm and 65 (52.4%) in the self-led arm. The primary reason for discontinuing the process was lack of patient response to contact to schedule their genetics visit (n = 109, 35 patient-led, 74 assistant-led). There was significantly more loss to follow up in the assistant-led arm versus the self-led arm (p < 0.001). Of those who completed VGE, the median age was 66 years, with no difference between the two arms (p = 0.66). Participants primary identified as white (n = 96, 91%) and non-Hispanic (n = 100, 94%). There was no difference in uptake of genetic testing (p = 0.09) between patient and assistant led VGE. Conclusions: A randomized intervention suggests no difference in genetic testing uptake when pre-test VGE occurs with an assistant or is patient-led. Analyses of satisfaction, decision conflict, and knowledge are needed to evaluate if patient-led VGE is a suitable alternative to GC. Loss to follow up given standard of care scheduling approaches for assistant-led VGE suggests pre-test VGE may be better delivered during oncology visits. Additional evaluation of the facilitators and barriers, in addition to larger multi-center studies, are required to consider patient-led pre-test VGE as a primary method of pre-testing genetic education.

Impact of provider education on prostate cancer genetic counseling referrals

59

Background: Guidelines recommend germline genetic not only for men with advanced and metastatic prostate cancer but also those with NCCN-high risk disease. Many men harboring germline DNA repair defects would not have met criteria for testing under previous guidelines (Nicolosi et al, JAMA Oncol 2019). Knowledge of germline mutations is pertinent due to recent regulatory approval of PARP inhibitors olaparib and rucaparib and guides screening for first-degree relatives who are at increased risk for other cancers (Pritchard et al, NEJM 2016). Knowledge gaps for germline genetic testing have been previously described (Loeb et al, Cancer Treat Res Commun 2020). Through a series of educational sessions, we sought to increase utilization of appropriate genetic services for men with prostate cancer. Methods: Starting March 2021, virtual educational presentations were held for nurse navigators, urologists, and medical oncologists throughout our large community-based healthcare system. Surveys were distributed following each presentation to measure clinicians’ perception of their knowledge regarding prostate cancer genetics referrals on a five-step scale. Prostate cancer patient referral data was measured from September 2020 to August 2021, six months prior to and after the presentations. Results: Self-reported understanding of prostate cancer genetics referral practices following the educational presentations increased by an average of 1.7/5 steps (2.5 to 4.2/5) for physicians and 1.4/5 steps (2.9 to 4.1/5) for nurse navigators. From March to August 2021, there were 107 genetic referrals for prostate cancer (average 17.8 referrals/month) compared to 49 referrals from September 2020 to February 2021 (8.2 referrals/month). Conclusions: Prostate cancer genetics referrals increased 118% following educational presentations to urologists, medical oncologists, and nurse navigators. This correlates with an improvement in self-reported knowledge gaps. Provider education interventions may improve access to genetic services for men with prostate cancer. The increase in referrals likely does not account for all patients meeting criteria for germline testing. Work is ongoing to calculate the number of referrals as a proportion of the eligible population.[Table: see text]

NEXT: A single-arm, phase 2, open-label study of adjuvant nivolumab after completion of chemo-radiation therapy in patients with localized muscle-invasive bladder cancer

506

Background: Nivolumab has known efficacy as adjuvant therapy after radical cystectomy in localized muscle invasive bladder cancer (MIBC). We are evaluating the efficacy of nivolumab adjuvant to definitive chemo-radiation therapy (CRT) in MIBC. Methods: In the NEXT study, we are currently enrolling patients with localized MIBC undergoing standard CRT. Participants are started on nivolumab 480 mg IV every 4 weeks (up to 12 doses) within 90 days of completion of CRT. Cystoscopic and scan-based assessments are done every 3 months for the first two years (yrs). The primary endpoint is failure-free survival (FFS) at 2 yrs from the start of CRT, with failure defined as local or systemic disease recurrence. Secondary endpoints include toxicity and quality of life (QOL) assessments. We have planned correlative studies on peripheral blood and tumor tissue. We performed a protocol-defined interim safety and efficacy analysis to assess the 6-month FFS rate with CRT and adjuvant nivolumab. Results: From 8/03/2017 to 9/28/2021, 20 patients were enrolled at two centers; median age is 76 yrs, clinical stage range is T2-T4b, N0-N+, M0; the median number of nivolumab cycles is 6.5, and the median follow-up is 8.9 months. The estimated 6-month FFS rate is 88.2% (95% CI 74.2% - 100%). Disease has progressed in 9 patients, of which 4 have local bladder recurrence (T1 in 3/4) and 5 have distant metastases. The estimated median FFS is 17.1 months (95% CI 8.71 months - infinity). Grade ≥3 treatment-related adverse events (AEs) are noted in 3/20 patients (15%): elevated transaminases, diarrhea, and polymyalgia rheumatica. Grade 3 radiation therapy oncology group (RTOG) AEs occurred in 2 patients. QOL measures are serially evaluable in 13 patients for the first 3 months of adjuvant nivolumab, and are stable in the domains of disease-related physical symptoms, treatment side effects, and function/well-being, while are significantly improved (p=0.023) in the domain of disease-related emotional symptoms. Conclusions: In this first report of the role of immunotherapy adjuvant to CRT for localized bladder cancer, adjuvant nivolumab is well tolerated and has promising efficacy. Clinical trial information: NCT03171025.

Impact of pretest video genetic education in prostate cancer patients: Do patients need us?

68

Background: Germline genetic testing criteria for individuals with prostate cancer (PCa) are expanding. Alternative genetic service models are needed to meet increased need for genetic testing. Studies have shown no difference in genetic testing uptake, satisfaction, or knowledge when patients undergo face-to-face genetic counseling compared to pre-test video genetic education (VGE). Data is limited comparing options for how video genetic education is delivered. This study evaluated the impact of pre-test VGE when facilitated by a genetic counseling assistant (assistant-led) or self-completed by the patient (patient-led). Methods: Individuals with PCa referred for genetic counseling received pre-test VGE. Patients were randomized so that this process involved meeting with a genetic counseling assistant or completed at the patient’s convenience via email instructions. Pre-test VGE included family history completion via electronic software and viewing of informational video. VGE completion and genetic testing uptake were measured for all participants. Questionnaires regarding satisfaction, and knowledge were optional for participants after VGE completion. Data was analyzed using t-test and Fisher’s exact. Results: Eighty-one individuals referred for genetic counseling from October 2020-March 2021, and 78 individuals were randomized (1:1) to assistant-led or patient-led VGE, with 39 individuals in each arm. After removing patients for technological limitations, loss to follow up, and procedural withdrawals, there were 18 patients in the assistant-led arm, and 16 patients in the patient-led arm. The primary reason for discontinuing the process was lack of response to phone and electronic contacts to schedule their genetics visit (n = 22). The median age was 64.5 years, with no difference between the two arms (p = 0.698). Participants identified primarily as white/Caucasian (n = 32, 94%). In the assistant-led group, all participants elected to undergo germline genetic testing and 13 (81%) opted for genetic testing in the patient-led group. There was no difference in genetic testing uptake between the two arms (p = 0.094). Nine patients in the patient-led group and eight patients in the assistant-led group completed the questionnaires. There was no difference in satisfaction with their VGE experience (p = 0.815) or knowledge using the KnowGene scale (p = 0.120). Conclusions: Preliminary data suggests there is no difference in genetic testing uptake when pre-test VGE is facilitated by a genetic counseling assistant or self-led by the patient. Given no preliminary differences in satisfaction and knowledge, patient-led pre-test VGE may serve as a viable option prior to germline testing in PCa patients. Additional research is needed with larger sample size. Furthermore, evaluation of the facilitators and barriers of VGE is needed as there was significant drop off in completion of video pre-test VGE.

Urban families ameliorate rural genitourinary cancer disparities

25

Background: Previous studies have shown that individuals with cancer who live in rural areas have worse cancer-specific outcomes compared to their urban counterparts. Differences in access to high-quality cancer care and adequate social support may explain some of the observed disparity. Rural patients with relatives in urban areas may have better access to care via an increased ability to navigate the healthcare system than their rural counterparts without relatives in urban areas. In this study, we examine the possibility of a family-based social capital effect on genitourinary cancer survival. We hypothesized that rural patients who have family members living in urban areas have survival outcomes similar to their urban counterparts. Methods: We performed a retrospective cohort analysis of individuals diagnosed with genitourinary cancers, including prostate, bladder, kidney, penile, and testicular cancers. We constructed familial networks using the Utah Population Database (UPDB). Patients were classified as living in either rural or urban areas based on the rural-urban commuting area (RUCA) codes associated with their zip code of residence at the time of cancer diagnosis. Adult first degree relatives (siblings, parents, children) were identified and classified as urban or rural based on the zip code or county of residence at the time of the patients’ diagnosis or, when unavailable, the county or zip code of residence before or after diagnosis. Overall survival (OS) was analyzed using Cox proportional hazards models. Results: We identified 24,746 individuals diagnosed with genitourinary cancer between 1968-2018. Median follow-up was 8.72 years. After adjusting for sex, age, race, cancer type, health improvement index (HII), and Simpson’s diversity index, urban patients had the best OS at 5 and 10 years (reference group). Rural cancer patients without an urban first degree relative had the worst outcomes with OS hazard ratios at five and ten years of 1.4 (CI 1.23-1.58) and 1.4 (CI 1.26-1.55), respectively. Having an urban first degree relative ameliorated much of the urban-rural disparity with five- and ten-year OS hazard ratios of 1.19 (CI 1.07-1.31) and 1.12 (CI 1.03-1.21), respectively. Conclusions: Individuals diagnosed with cancer who live in rural areas have worse survival as compared to their urban counterparts, but this relationship appears to be heavily influenced by the presence or absence of relatives who live in urban areas. Further research is needed to better understand the mechanisms through which having an urban family member may contribute to improved cancer outcomes for rural patients. This may help in the crafting of policies that can reduce urban-rural cancer disparities. Funding: Research reported in this publication was supported by the National Cancer Institute of the National Institutes of Health (K08CA234431 & P30CA042014-31S2). The content does not represent the views of the National Institutes of Health.

Low-value prostate cancer screening among young men with private insurance

240

Background: Debate remains about the value of Prostate-specific antigen (PSA) based prostate cancer screening among men aged 55-69 (USPSTF Grade C). However, no professional society or guideline recommends PSA based prostate cancer screening in men younger than age 40. This study aims to understand the risk of PSA testing exposure in young men, and we hypothesize that substantial low-value testing occurs in this population. Methods: We performed a retrospective analysis of claims data from the MarketScan database to identify men aged 18 to 39 without prostate cancer who received a PSA test from 2008 to 2017. For the primary analysis, men were required to be continuously in the database for least 5 years. Age groups were stratified to include: men less than 25, 25-29, 30-34, and 35-39 years. Secondary analysis did not limit subjects to those with 5 years of continuous data and explored the association of Charlson Comorbidity Index (CCI), lower urinary tract symptoms, erectile dysfunction, depression/anxiety, prostate cancer screening, infertility, and hypogonadism with PSA testing in young men. We used logistic regression to determine which of the factors were associated with PSA testing in young men. Results: We identified claims for 40,164,773 adult men who met study criteria. Of these men, 3,230,748 were continuously in the Marketscan database for at least 5 years. The cumulative risk for receiving a PSA over 5 years for men under 40 is 2.5%. Stratified by age, men aged 35-39 are at highest risk (Table). Logistic multivariable regression showed that, relative to all men between 18 and 40, patients in this age group who received a PSA were more likely to be diagnosed with hypogonadism (OR 20.55, 95% CI 20.39-20.71) or lower urinary tract symptoms (OR 9.34, 95% CI 9.26-9.41). Higher CCIs appeared to correlate with a decreased rate of PSA testing. This population was not significantly more likely to be diagnosed with infertility, depression, or anxiety. Conclusions: PSA screening for men under 40 is not uncommon, especially when associated with concomitant genitourinary symptoms. At a population level, this represents substantial low-value testing. Interventions aimed at clarifying the relationship between common urologic conditions and prostate cancer, the extremely low incidence of prostate cancer in this age group, and the lack of guidelines supporting this practice may help decrease low-value PSA testing. Funding: Research reported in this publication was supported by the National Cancer Institute of the National Institutes of Health under Award Number K08CA234431. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.[Table: see text]

The effect of neoadjuvant chemotherapy on quality of life for patients with muscle invasive bladder cancer (MIBC) undergoing cystectomy

e18614

Background: To examine the relationship between neoadjuvant chemotherapy (NAC) clinical risk factors, and patient reported quality of life in patients with MIBC undergoing cystectomy. Methods: cT2-T4, N0, M0 MIBC patients who underwent radical cystectomy were identified from a prospectively maintained institutional outcomes database. PROMIS-Ca surveys (physical function (PF), pain interference, fatigue, depression, and anxiety domains) were administered at consultation and follow-up as part of routine clinical care. Patients were stratified as receiving NAC vs. none and surveys were anchored to date of cystectomy. Non-parametric kernel regressions with variance-covariance matrix bootstrapping were used to estimate the mean effect of covariates on each domain T-score with 95% confidence intervals. Covariates were: body mass index, smoking history, age, Charlson comorbidity score, pT and pN stage, urinary diversion-type, and survey time relative to the cystectomy date. T-score changes over time were modeled by including univariable parameters with a P<=0.1 in a multivariable model (MVA) for each domain and predicting the marginal means at date of cystectomy, 6 and 12 months postop. Results: The median age was 68 (IQR 60-73) years. NAC was received by 69/134 patients (40 Gem/Cis, 24 MVAC, 5 unknown). On univariate analyses NAC significantly reduces PF (mean change in t-score, 95%CI; -2.4, -3.7 to -0.8, p=0.001), trends toward more pain (0.94, -0.20 to 1.78, p=0.074), but does not influence fatigue, depression or anxiety. Other covariates with p<0.05 reducing PF were BMI (-0.31, -0.53 to -0.03), pT4 vs pT1-2 (-0.31, -0.53 to -0.03), Charlson 1 vs 0 (-0.31, -0.53 to -0.03), age (-0.31, -0.53 to -0.03), and days from surgery (-0.31, -0.53 to -0.03). Table shows how t-scores predicted from the MVA change over time. Conclusions: MIBC patients have mild to moderate impairment in physical function, fatigue, and pain before and after cystectomy, suggesting a need for increased focus on rehabilitation and wellness programs. Although the univariable analysis implies there may be differences in PF and Pain for those receiving NAC vs none, future studies with increased power are needed to properly adjust for the interplay of other significant covariates.[Table: see text]

Phase 2 trial of gemcitabine, cisplatin, plus nivolumab with selective bladder sparing in patients with muscle- invasive bladder cancer (MIBC): HCRN GU 16-257

4503

Background: Transurethral resection of bladder tumor (TURBT) plus systemic therapy has been known for decades to achieve durable bladder-intact survival in a subset of patients with MIBC but efforts to advance this paradigm have been complicated by (a) lack of prospective studies exclusively testing cisplatin-based neoadjuvant chemotherapy, (b) lack of rigorous methods to define clinical complete response (cCR) and its association with long term outcomes and (c) limited understanding of the role of “salvage” cystectomy. Methods: Eligible patients were cisplatin-eligible with cT2-T4aN0M0 urothelial bladder cancer. Patients received 4 cycles of gemcitabine, cisplatin, plus nivolumab followed by clinical restaging including urine cytology, MRI/CT of the bladder, cystoscopy and bladder/prostatic urethral biopsies. Patients achieving a cCR (normal cytology, imaging, and cT0/Ta) were eligible to proceed without cystectomy and receive nivolumab q2 weeks x 8 followed by surveillance; otherwise, patients underwent cystectomy. Coprimary endpoints included (1) cCR rate and (2) ability of cCR to predict 2-year metastasis-free survival (MFS). The key secondary endpoint was the impact of genomic alterations in baseline TURBT (TMB, ERCC2, FANCC, RB1, ATM) on performance of cCR for predicting MFS. The cCR rate coprimary endpoint, and interim analysis of 1-year outcomes, are reported. Results: Between 8/2018-11/2020, 76 patients were enrolled at 7 sites (male 79%, median age 69; cT2 = 56%, cT3 = 32%, cT4 = 12%) and 64 (84%) have completed post-cycle 4 restaging; 31/64 achieved a cCR (48%; 95% CI 36%, 61%). The median follow-up of cCR patients is 13.7 months (range, 2.5-24 months). One cCR patient opted for immediate cystectomy (pTaN0M0). Outcomes for the entire cohort are summarized in the table below. Local recurrence has occurred in 8/31 cCR patients and 6 underwent cystectomy (pT0N0 = 1, pTaN0 = 1, pTisN0 =1, pT2N0 = 2, pT4N1 = 1). TMB ≥ 10 mut/Mb (p=0.02) or mutant ERCC2 (p=0.02) were associated with cCR or pT0. Conclusions: TURBT + gemcitabine, cisplatin, plus nivolumab achieves stringently defined cCR in a large subset of patients with MIBC. 1-year bladder intact survival is possible though the durability of responses, and role of genomic biomarkers in management algorithms, requires longer follow-up. Clinical trial information: NCT03558087. [Table: see text]

The oncology hospital at home: Health care utilization outcomes from the huntsman at home trial

7000

Background: Unplanned hospitalizations and emergency department (ED) visits are common during cancer care. Providing acute hospital level care at home may add value by decreasing hospital and ED use. We conducted the first evaluation of an oncology Hospital-at-Home program, Huntsman at Home (H@H). Methods: The Huntsman Cancer Institute began H@H services in 2018 and accepts referral of cancer patients for acute-medical or post-surgical care at home. Patients are admitted who require continued acute level medical care after hospitalization or have emergent unstable symptoms related to treatment or disease progression that would otherwise require ED evaluation or hospitalization. Prospectively, patients referred to H@H from 8/2018 through 10/2019 were compared to a usual care comparison group (UC) drawn concurrently from patients living within the Salt Lake City metropolitan area who qualified for admission to H@H, but lived outside the service zip codes. Probability of H@H enrollment propensity scores were constructed via random forest from patient descriptors and health care utilization at admission. We used an intent-to-treat approach for analysis. Primary outcomes were hospitalizations, length of stay (LOS), ED visits and cumulative charges over 30 and 90 days post admission to either group. Comparisons were made by generalized linear models, stratified by tertiles of H@H vs. UC propensity score. Results: 367 patients, 169 H@H and 198 UC, were evaluated. The average age was 62 yrs, 85% were Caucasian, and 77% had stage IV cancer. Propensity score distributions were overlapping, demonstrating group comparability. A variety of cancers were represented; the most common being colon, gynecologic, prostate and lung cancers. Compared to UC, H@H patients were more likely to be female (61% vs 43%) and during the month prior to admission, showed a trend towards longer LOS if hospitalized (6.7 vs 5.5 days). During the first 30 days after admission, propensity stratified comparisons showed H@H patients with lower hospital LOS (mean reduction 1.19 days, p=0.022), 56% lower odds of unplanned hospitalizations (OR 0.44, p=0.001), 45% lower odds of ED visits (OR 0.55, p=0.037) and 50% lower cumulative charges (mean ratio 0.50, p<0.001) compared to UC. Results over 90 days were similarly robust. Conclusions: In the first reported trial of an adult oncology Hospital at Home program, there was strong evidence for reduced hospitalizations, ED visits, and cost. Oncology Hospital at Home programs show promise for increased patient-centered care while simultaneously improving value.

NEXT: A phase II, open-label study of nivolumab adjuvant to chemoradiation in patients (pts) with localized muscle invasive bladder cancer

TPS605

Background: In pts with localized muscle invasive bladder cancer (MIBC), trimodality bladder preserving therapy (TMT), with transurethral resection of bladder tumor, radio-sensitizing chemotherapy and definitive radiation, has up to a 50% risk of local and systemic relapse during the 2-year post treatment phase. We hypothesize that by inhibiting immune checkpoints, chemo-radiation induced tumor specific immune response will be enhanced both locally and abscopally, resulting in better failure-free survival (FFS). In the NEXT trial, we evaluate the efficacy of nivolumab after completion of the TMT in this setting. Methods: Pts with localized MIBC who have completed standard TMT are eligible. Pts receive nivolumab 480 mg intravenously every 4 weeks for up to 12 doses. Treatment with nivolumab begins within 90 days of completion of TMT. Subjects undergo surveillance cystoscopic and scan based assessments on study. Archived tumor tissue at baseline and at relapse is obtained for correlative studies. The primary endpoint is 2-year FFS. Secondary endpoints include FFS at 2 years in patients with intact bladder, rate of radical cystectomy (RC), cystoscopic local control, distant FFS in patients with intact bladder and those that undergo RC, overall survival, toxicity and quality of life. Exploratory endpoints include to characterize changes in immune cell subsets that can be correlated with clinical outcome and to assess the correlation of response to PD-L1 expression in pretreatment tumor tissue in the study subjects. The planned sample size for this single arm, open label trial is 28 pts. Kaplan-Meier methods will be used to plot survival endpoints and cystoscopic local control rates. Exact binomial methods will be used to provide 6 months, 1-year and 2-year estimates for these endpoints. The sample size justification is based on the maximum width of a two-sided 95% binomial confidence interval for 2 year FFS. With 28 evaluable subjects, a 95% exact binomial confidence interval, estimated using the method of Clopper-Pearson, will extend no more than 20% from the observed FFS. Clinical trial information: NCT03171025.

Validation of plasma miR-371a-3p expression in patients with metastatic and early stage germ cell tumor

526

Background: Identification of relapsing/residual viable germ cell malignancy (GCM) is often challenging in patients with CSI on surveillance or with residual post-chemotherapy disease. The presence of a biomarker for GCM would overcome the uncertainty of the current methods and improve the quality of care of those patients. Methods: A 2-cohorts pilot study involving patients with clearcut evidence of GCM (clinical stage IS, metastatic and GCM prior orchiectomy) for the development cohort and patients with CSI with or without signs of tumor relapse and patients with metastatic GCM post-chemotherapy for the validation cohort. Blood samples collected in Streck tubes were obtained prior to chemotherapy for the development cohort and post-orchiectomy, at the time of suspicious relapse or post-chemotherapy in the validation cohort. Plasma miR-371a-3p (miR371) was analyzed by RT-PCR. Positive predictive value (PPV), sensitivity, specificity, negative predictive values (NPV) and AUC of the ROC for miR371 and standard diagnostic tools (CT scan, AFP, BHCG and LDH) were calculated correlating qualitative miR371 expression to the presence of viable GCM. Results: 132 patients were enrolled into the development (33 pts) and validation (99 pts) cohorts. Within the development cohort 31/33 pts were miR371 positive, 2/33 pts were negative. 31 true positives were found among the 31 miR371 positive patients for a PPV of 100% (31/31). Two true negatives were found among the 2 patients who had no miR371 expression identified (teratoma, lymphoma). The validation cohort was chosen to evaluate the methodology among patients with predicted lower volumes or no clinically apparent disease. 13/99 patients within the validation cohort were miR371 positive and all 13 had subsequent confirmation of viable GCM. For the overall study of 132 pts, PPV was 100% (46/46), NPV 98%, sensitivity 96% and specificity 100%, the AUC of the ROC was 0.96. Conclusions: Detectable circulating miR-371a-3p levels predict viable GCM and may represent a strategy for biological rather than radiographic assessment for surveillance of early stage and for post-treatment patients. Larger studies to validate these and like results have been planned.