MRI characteristics and oncological follow-up of patients with ISUP grade group 4 or 5 prostate cancer

OBJECTIVES

To analyze multiparametric MRI (mpMRI) characteristics of patients with International Society of Urological Pathology (ISUP) grade group (GG) 4 or 5 prostate cancer (PC) and to correlate MRI parameters with the occurrence of biochemical recurrence (BCR) after radical prostatectomy (RPE).

METHODS

In this single-center cohort study consecutive patients with mpMRI and ISUP GG 4 or 5 PC were retrospectively analyzed. Clinical, MR-guided biopsy, and diagnostic mpMRI parameter were assessed. A subcohort of patients with RPE and follow-up was analyzed separately. A univariate and multivariate analyses were performed to determine parameters that are associated to patients with BCR after RPE.

RESULTS

145 patients (mean age 70y, median PSA 10.9 ng/ml) were analyzed. 99% had a PI-RADS classification of 4 or 5, 48% revealed MRI T3 stage, and median diameter of the MRI index lesion (IL) was 15 mm. IL showed a median ADC value of 668 ×10-6 mm2/s and exhibited contrast enhancement in 94% of the cases. For patients with follow-up after RPE (n = 82; mean follow-up time 68 ± 27 m), MRI parameters were significantly different for contact length of the IL to the pseudocapsule (LCC), MRI T3 stage, and IL localization (p < 0.05). Higher PSAD and MRI T3 stage were independent parameters for the risk of BCR when incorporating clinical, biopsy, and MRI parameters.

CONCLUSION

ISUP GG 4 or 5 PC has distinctive characteristics on mpMRI and were detected on MRI in all cases. In addition, higher PSAD and MRI T3 stage were significant predictors for BCR after RPE.

Cabozantinib + nivolumab in adult patients with advanced or metastatic renal cell carcinoma: A retrospective, non-interventional study in a real-world cohort

628

Background: Standard treatment for 1st-line mRCC are IO-combinations. Data from real-world collectives are rare. In this multicenter study, we therefore evaluated safety and effectiveness of cabozantinib/nivolumab in Germany. Methods: Data were collected retrospectively from eight GU cancer centres in Germany. Patients (pts) with advanced or metastatic renal cell carcinoma (mRCC) were eligible. Treatment with cabozantinib 40 mg orally + nivolumab 240 or 480 mg i.v. was mandatory and administered according to routine care. Adverse events (AEs) were reported according to CTCAE 5.0. Objective response rate per RECIST 1.1 and Progression Free Survival (PFS) were calculated from start of treatment to progression or death. Descriptive statistics and KM-plots were utilized, where appropriate. Results: 67 suitable pts (62.7% male) with median age of 67.6 years were included. The most common histology was clear cell RCC (ccRCC) in 67.2% (n=45). Nephrectomy was performed in 56.7% (n=38). ECOG 0-1 was 76.1% (n=51). IMDC scores were: 0 in 11 (16.4%), ≥ 1 in 45 (67.1%), missing in 11 pts (16.4%). 29.9% (n=20) required dose reductions or interruptions. Partial response was documented in 46.3% (n=31), stable disease in 32.8% (n=22), and progressive disease in 4.5% (n=3) as best overall response. Data were missing in 14.9% (n=10). Median Follow-up was 8.3 mo, median treatment duration was 6.0 months, PFS rate at 6 month was 81.9% overall (79.3% for ccRCC; 85.9% for non-ccRCC). AEs (all grades) were reported in 82.1% (n=55) and 47.8% (n=32) for grade 3-5. Elevated liver enzymes (40.3%), diarrhea (22.4%) and hand-foot-syndrome (20.9%) were the 3 most frequent AEs of any grade and causality. Conclusions: In this real-world cohort of mRCC pts. cabozantinib + nivolumab was shown to be safe and feasible. While no new safety signals were reported, a reduced dose was frequently utilized. Our data support the use of cabozantinib + nivolumab as a first-line standard. Major limitations were the retrospective data capture and short follow-up of our study.

Treatment patterns, indicators of receiving systemic treatment, and clinical outcomes in metastatic urothelial carcinoma: A retrospective analysis of real-world data in Germany

464

Background: This study assessed real-world treatment (tx) and outcomes in patients with metastatic urothelial carcinoma (mUC) in Germany. Methods: Using 2 statutory health insurance (SHI) claims databases (SHI 1 and SHI 2; 2013-2020, ≈8 million insured), adults with an incident mUC diagnosis from 2015-2019 were identified. Those with other malignant tumors were excluded. Patients were observed for ≥12 mo after incident mUC diagnosis (index) or until death. Treated patients were delineated into 3 groups based on first-line (1L) tx received: platinum-based chemotherapy (PB CT), non–PB CT, and immunotherapy (IO). Patient characteristics were analyzed descriptively. Multivariable logistic regression was used to identify factors associated with receiving tx. Overall survival (OS) was calculated from 1L tx initiation by Kaplan-Meier estimation. Analyses were done separately for each database. Results: The study included 3,226 patients with mUC (male, 70.8%), with a mean (SD) follow-up of 13.8 mo (16.1). The mean (range) age was 73.8 y (23-99), and the mean (SD) Elixhauser Comorbidity score was 17.6 (11.4). Overall, 1,286 patients (39.9%) received tx in the first 12 mo post index; PB CT was the most common 1L tx (n=825, 64.2%), followed by non–PB CT (n=322, 25.0%) and IO (n=139, 10.8%). Over time, the number of patients receiving 1L tx increased (2015, 35.8%; 2019, 45.7%). Multiple factors were associated with a higher likelihood of receiving 1L tx: younger age (OR, 0.93), male sex (OR, 0.83), lower comorbidity score (OR, 0.97), previous UC-related interventions (OR, 1.65), and a more recent mUC diagnosis (OR, 1.11). In treated patients, the unadjusted median OS (interquartile range [IQR]) from index diagnosis was 13.7 mo (7-33) for SHI 1 and 13.8 mo (7-42) for SHI 2. In untreated patients, the median OS (IQR) from index diagnosis was 3.0 mo (1-11) for SHI 1 and 3.6 mo (1-18) for SHI 2. The median OS (IQR) after 1L tx initiation in PB CT–treated patients was 12.9 mo (6-33) for SHI 1 and 13.8 mo (7-49) for SHI 2; in non–PB CT–treated patients was 11.2 mo (4-36) for SHI 1 and 6.5 mo (3-15) for SHI 2; and in IO-treated patients was 4.11 mo (2-14) for SHI 1 and 8.19 mo (3 to not reached) for SHI 2. Conclusions: Our study describes real-world tx patterns/rates and clinical outcomes in patients with mUC in Germany, and highlights that the majority received no systemic tx within the first 12 mo, despite a positive trend in 1L tx rates over time. Treated patients were more likely to be younger, male, and have fewer comorbidities vs untreated patients. Systemic tx was associated with longer OS. Among treated patients, OS was longer in those receiving 1L PB CT vs other 1L tx. Future research should explore the unmet need in untreated patients to confirm alignment with updated tx guidelines and newer standards of care.

Establishment and Evaluation of Dual HDAC/BET Inhibitors as Therapeutic Options for Germ Cell Tumors and Other Urological Malignancies

Urological malignancies represent major challenges for clinicians, with annually rising incidences. In addition, cisplatin treatment induced long-term toxicities and the development of therapy resistance emphasize the need for novel therapeutics. In this study, we analyzed the effects of novel histone deacetylase (HDAC) and bromodomain and extraterminal domain-containing (BET) inhibitors to combine them into a potent HDAC-BET-fusion molecule and to understand their molecular mode-of-action. Treatment of (cisplatin-resistant) germ cell tumors (GCT), urothelial, renal, and prostate carcinoma cells with the HDAC, BET, and dual inhibitors decreased cell viability, induced apoptosis, and affected the cell cycle. Furthermore, a dual inhibitor considerably decreased tumor burden in GCT xenograft models. On a molecular level, correlating RNA- to ATAC-sequencing data indicated a considerable induction of gene expression, accompanied by site-specific changes of chromatin accessibility after HDAC inhibitor application. Upregulated genes could be linked to intra- and extra-cellular trafficking, cellular organization, and neuronal processes, including neuroendocrine differentiation. Regarding chromatin accessibility on a global level, an equal distribution of active or repressed DNA accessibility has been detected after HDAC inhibitor treatment, questioning the current understanding of HDAC inhibitor function. In summary, our HDAC, BET, and dual inhibitors represent a new treatment alternative for urological malignancies. Furthermore, we shed light on new molecular and epigenetic mechanisms of the tested epi-drugs, allowing for a better understanding of the underlying modes-of-action and risk assessment for the patient.

Using Circulating Tumor DNA To Guide Adjuvant Therapy in Bladder Cancer: IMvigor010 and IMvigor011

Recent data from IMvigor010 impressively demonstrate the potential of circulating tumor DNA (ctDNA) as a prognostic and a predictive biomarker in patients with urothelial carcinoma. Although ctDNA status was prospectively assessed, the published data are only exploratory and require further prospective validation. Results from the IMvigor011 trial are therefore eagerly awaited.

The PRIMETEST trial: Prospective phase II trial of primary retroperitoneal lymph node dissection (RPLND) in stage II A/B patients with seminoma

420

Background: Primary retroperitoneal lymph node dissection (RPLND) in patients (pts) with stage II A/B seminoma without adjuvant local or systemic treatment is an experimental treatment to avoid radio- or chemotherapy–related toxicity. The prospective PRIMETEST trial (NCT 2015053664) evaluates recurrence-free (RFS) and overall survival (OS) as well as surgical safety of patients with clinical stage II A/B seminoma undergoing RPLND without adjuvant treatment. Interim results had been presented at ASCO GU 2019. Methods: Primary endpoint of the study is PFS after a median follow-up of 36 months. We performed unilateral open or robotic RPLND in pts with unilateral retroperitoneal lymphnode metastases < 5 cm (stage IIA and IIB) with human chorionic gonadotropin (HCG) < 5 mU/ml. Pts were included with either stage IIA/B at initial diagnosis, at time of recurrence under active surveillance, or after adjuvant carboplatin in clinical stage I. The phase II trial was designed to exclude the upper limit of a 95% confidence interval at 30% recurrences. Results: Trial accrual was completed in a single center from May 2016 to June 2021 with 33 consecutive pts. 13 and 20 pts presented with stage IIA and IIB, respectively. 9 pts had initial stage II, 19 pts presented with recurrence during active surveillance, 5 pts had adjuvant carboplatin. At time of RPLND median HCG was 0.1 mU/ml (range 0 – 2.2 mU/ml). Open and robotic RPLND was performed in 14 (42 %) and 19 (58 %) pts, respectively. One patient had to be converted from robotic to open surgery. Median size of metastasis on histological report was 28 mm (range 11 – 69 mm) with a median OR time of 169 min (range 101 – 351 min). Median estimated blood loss was 50 ml (range 0 – 400 ml). Higher grade complications (Clavien Dindo ≥ III) occurred in 3/ 33 pts (9 %; 2 x pulmonary embolism, 1 x ureteral stricture requiring ileal ureter substitute). Of 33 pts, 2 pts withdrew their consent during follow-up. As of September 1, 2021, the median follow-up is 26 months (range 2 – 56 months). Up to now we observed 10 recurrences (31 %). RFS is 69 % with a median time from RPLND to relapse of 6 months (range 3 – 36 months). The recurrences included infield recurrences in 3/ 10 cases. 5 and 5 recurrences were observed in stage II A and B pts, respectively. Analysis of predictive factors showed vascular invasion present in 5/ 10 recurrences. Half of pts with relapse were treated with robotic RPLND and open RPLND, respectively. All pts with relapse underwent standard chemotherapy and are currently without evidence of disease. Conclusions: Open and minimally invasive surgical resection of small volume, unilateral seminoma metastasis is feasible with acceptable toxicity. Current recurrence-free survival rates suggest this approach as an option to avoid standard treatment (chemotherapy, radiotherapy) in selected patients. Clinical trial information: NCT2015053664.

Final analysis of a non-interventional study on cabozantinib in patients with advanced renal cell carcinoma after prior checkpoint inhibitor therapy (CaboCHECK)

357

Background: Data for cabozantinib after IO-combinations in metastatic renal cell carcinoma (mRCC) remain scarce. We therefore evaluated safety and effectiveness of cabozantinib after failure of IO-based therapies. Methods: Data from patients (pts) with mRCC and cabozantinib treatment after IO-based therapy was retrospectively collected from medical records. Primary endpoint was the incidence of serious adverse events (SAEs). Response rate was assessed clinically (CRR) and/or according to RECIST 1.1. Overall Survival (OS) and Progression Free Survival (PFS) were assessed from start of therapy and data were compared for pts with starting dose of 60 mg (cohort A) vs < 60 mg (cohort B) in a post-hoc analysis. Descriptive statistics and KM-plots were utilized, where appropriate. Results: This final analysis (cut off 08-Oct-21) assessed 56 eligible pts (71.4% male) with median age of 66 yrs. 87.5% (n = 49) had previous nephrectomy. 66.1% (n = 37) had clear cell RCC. 89.3% (n = 50) had ≥2 previous lines. ECOG ≤1 was 33.9% (n = 19). IMDC factors were 0 in 2 (3.6%), ≥1 in 21 (37.5%), missing in 31 pts (55.4%). 62.5% (n = 35) started at reduced dose. 55.4% (n = 31) required dose reductions and 1.8% (n = 1) discontinuation. Median treatment duration was 6.1 months (m). PR was 10.7% (n = 6), SD 19.6% (n = 11), PD 12.5% (n = 7) and missing in 57.1% (n = 32). Median OS and PFS were 15.34 m (95% CI 8.94, 20.93) and 6.34 m (95% CI 5.29, 8.25) in the ITT, 10.48 m (95% CI 6.01, 34.14) and 6.51 m (95% CI 2.99, 10.87) in cohort A and 16.46 m (95% CI 9.56, 23.33) and 6.34 m (95% CI 4.86, 8.71) in cohort B, respectively. All grade AEs and grade 3-5 AEs were 87.5% (n = 49) and 44.6% (n = 25) in the ITT, 95.0% (n = 19) and 55.0% (n = 11) in cohort A and 85.7% (n = 30) and 40.0% (n = 14) in cohort B. SAEs were reported in 21.4% (n = 12) of pts, which were 30.0% (n = 6) of cohort A and 17.1% (n = 6) of cohort B. Treatment related SAEs were reported in 10.7% (n = 6) of pts, which were 15.0% (n = 3) in cohort A and 8.6% (n = 3) in cohort B. Conclusions: Cabozantinib directly after IO therapy was safe and feasible. No new safety signals were reported. A reduced starting dose was frequently utilized and was not associated with adverse outcomes. Our data supports the use of cabozantinib after IO-failure. Major limitation was the retrospective nature of our study.[Table: see text]

Efficacy and safety outcomes of darolutamide in patients with nonmetastatic castration-resistant prostate cancer with comorbidities and concomitant medications from ARAMIS

256

Background: Patients (pts) with nonmetastatic castration-resistant prostate cancer (nmCRPC) are primarily older, have comorbidities, and take concomitant medications. Darolutamide (DARO), a structurally distinct and highly potent androgen receptor inhibitor, significantly reduced the risk of metastasis by ̃2 years and the risk of death by 31% versus placebo (PBO) and demonstrated favorable safety and tolerability in the phase 3 ARAMIS trial. DARO also has low potential for drug−drug interactions. This post hoc analysis of ARAMIS evaluated overall survival (OS) and safety in pts with ongoing comorbidities and concomitant medications. Methods: Pts with nmCRPC were randomized 2:1 to DARO (n=955) or PBO (n=554) while continuing androgen-deprivation therapy. At the final data cutoff (Nov 15, 2019), OS and adverse events (AEs) were evaluated in pts with a median of ≤ and >6 comorbidities or ≤ and >10 concomitant medications in the double-blind period. HRs (95% CIs) were determined from univariate analysis using Cox regression. Results: The majority of pts had ≥6 comorbidities (53%; 795/1509) or received ≥10 concomitant medications (54%; 813/1509). For pts with ≤6 and >6 comorbidities, DARO prolonged OS vs PBO (HR 0.65 and 0.73, respectively). OS benefit of DARO vs PBO was consistent for pts with metabolic, cardiovascular (CV), and other comorbid disorders (HR range: 0.39–0.88). For pts receiving ≤10 and >10 concomitant medications, OS was prolonged with DARO vs PBO (HR 0.76 and 0.66, respectively). Subgroups of pts receiving concomitant medications for gastrointestinal/metabolic disorders, CV disease, urologic disorders, and pain/inflammation achieved similar OS benefit with DARO vs PBO (HR range: 0.45–0.80). Incidence of AEs and AEs leading to treatment discontinuation with DARO was comparable to PBO across subgroups by number of comorbidities and concomitant medications (Table). Conclusions: The OS benefit and safety of DARO remained consistent with that observed in the overall ARAMIS population, even in patients with a high number of comorbidities or concomitant medications. Clinical trial information: NCT02200614. [Table: see text]

Tailored immunotherapy approach with nivolumab in advanced transitional cell carcinoma (TITAN-TCC)

441

Background: Nivolumab (nivo) is an approved 2nd line treatment after platinum-based chemotherapy in metastatic urothelial carcinoma (mUC). Recent studies suggest improved outcomes for dual checkpoint inhibition in mUC in particular with higher ipilimumab (ipi) doses (nivo 1mg/kg + ipi 3mg/kg). TITAN-TCC uses a response-based approach starting with 4 doses of nivo (8 weeks) followed by nivo+ipi boosts in non-responders. Here we report cohort 2 of TITAN-TCC applying nivo1/ipi3 boost doses in patients after prior platinum-based chemotherapy (2nd/3rd line). Methods: Between April 2019 and February 2021 83 patients with histologically confirmed mUC (TITAN-TCC cohort 2) started with nivo 240mg Q2W induction. After 4 doses and tumor assessment at week 8 (i) non-responders (stable (SD)/ progressive disease (PD)) received 2-4 doses nivo1+ipi3 while (ii) responders (complete (CR)/ partial response (PR)) continued with nivo maintenance but could receive nivo1+ipi3 for later PD. Primary endpoint was confirmed investigator-assessed ORR per RECIST1.1. Using a Fleming single-stage phase II design 77 evaluable patients would provide a 90% power to reject the null-hypothesis that ORR was ≤20% at a one-sided 5% type I error if the true ORR was ≥35%. Secondary endpoints included activity of nivo monotherapy at week 8, remission rate with nivo+ipi boosts, progression-free survival (PFS), overall survival (OS), and safety. Results: Median follow-up time was 5.6 months. Of the patients, 78 (94%) were 2nd line. Median age was 68 years (range 37-84) and 57 patients (69%) were male. ORR with nivo monotherapy at first assessment (week 8) was 20.5%. Of the patients, 44 and 6 received nivo+ipi boosts after week 8 and for later PD, respectively. Confirmed objective response with nivo induction ± nivo+ipi boosts was achieved in 27/83 (32.5%) of the patients (significant > 20%, p < 0.01). Patients with PD-L1 expression in ≥1% of tumor cells had a numerically higher ORR (46% vs. 24% for PD-L1 negatives). Of the patients with initial SD after nivo induction, 4/13 (31%) achieved response upon boost. Of the patients boosted for PD, 9/37 (24%) improved. Median PFS was 1.9 months (95% CI 1.8-3.2), median OS was 7.6 months (95% CI 5.1-14.9). No new safety signals emerged. Conclusions: In patients after prior platinum-based chemotherapy treatment with nivo and nivo+ipi boosts in non-responders significantly improved ORR compared to the one reported for nivo as 2nd line monotherapy. Patients with PD-L1 positive tumors appear to benefit most. Our study provides further evidence for the added value of high dose (3mg/kg) ipilimumab in mUC. Clinical trial information: NCT0321977.[Table: see text]

[Imaging of oligometastatic disease in selected urologic cancers]

BACKGROUND

Local treatment of the primary or metastatic sites in urologic malignancies is promising when compared to systemic therapy alone, leading to the definition of a potentially curative oligometastatic state.

OBJECTIVES

Comparison of imaging modalities regarding local and metastatic tumor sites in urologic cancers.

METHODS

Review of comparative trials addressing quality criteria of imaging modalities.

RESULTS

Depending on primary tumor and metastatic site, conventional imaging modalities such as computer tomography (CT) and bone scintigraphy still represent the standard of care in Germany. Due to superior quality criteria, hybrid-imaging techniques were widely adopted for oncological staging and particular due to the new PSMA-ligand (PSMA-PET/CT) in prostate cancer imaging. The development of new radioisotopes as well as their clinical application remains a focus of current research.

CONCLUSIONS

High-quality diagnostic imaging modalities lay the groundwork for a precise definition of an oligometastatic state. By enabling treatment of the entire tumor burden, a delay of systemic therapy, longer progression-free survival, or even curative treatment may become achievable.

Efficacy of Platinum Rechallenge in Metastatic Urothelial Carcinoma After Previous Platinum-Based Chemotherapy for Metastatic Disease

BACKGROUND

Fit patients with metastatic urothelial carcinoma (mUC) receive first-line platinum-based combination chemotherapy (fPBC) as standard of care and may receive additional later-line chemotherapy after progression. Our study compares outcomes with subsequent platinum-based chemotherapy (sPBC) versus subsequent non-platinum-based chemotherapy (sNPBC).

MATERIALS AND METHODS

Patients from 27 international centers in the Retrospective International Study of Cancers of the Urothelium (RISC) who received fPBC for mUC and at least two cycles of subsequent chemotherapy were included in this study. A multivariable Cox proportional hazards model compared overall survival (OS) and progression-free survival (PFS).

RESULTS

One hundred thirty-five patients received sPBC and 161 received sNPBC. Baseline characteristics were similar between groups, except patients who received sPBC had higher baseline hemoglobin, higher disease control rate with fPBC, and longer time since fPBC. OS was superior in the sPBC group (median 7.9 vs 5.5 months) in a model adjusting for comorbidity burden, performance status, liver metastases, number of fPBC cycles received, best response to fPBC, and time since fPBC (hazard ratio, 0.72; 95% confidence interval, 0.53-0.98; p = .035). There was no difference in PFS. More patients in the sPBC group achieved disease control than in the sNPBC group (57.4% vs 44.8%; p = .041). Factors associated with achieving disease control in the sPBC group but not the sNPBC group included longer time since fPBC, achieving disease control with fPBC, and absence of liver metastases.

CONCLUSION

After receiving fPBC for mUC, patients who received sPBC had better OS and disease control. This may help inform the choice of subsequent chemotherapy in patients with mUC.

IMPLICATIONS FOR PRACTICE

Patients with progressive metastatic urothelial carcinoma after first-line platinum-based combination chemotherapy may now receive immuno-oncology agents, erdafitinib, enfortumab vedotin, or sacituzumab govitecan-hziy; however, those ineligible for these later-line therapies or who progress after receiving them may be considered for subsequent chemotherapy. In this retrospective study of 296 patients, survival outcomes and disease control rates were better in those receiving subsequent platinum-based rechallenge compared with non-platinum-based chemotherapy, suggesting that patients should receive platinum rechallenge if clinically able. Disease control with platinum rechallenge was more likely with prior first-line platinum having achieved disease control, longer time since first-line platinum, and absence of liver metastases.

Optimal pathological response after neoadjuvant chemotherapy for muscle-invasive bladder cancer: results from a global, multicentre collaboration

OBJECTIVES

To evaluate outcomes of patients achieving a post-treatment pathological stage of <ypT2N0 at radical cystectomy (RC) following neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC) to identify an optimal definition of pathological response.

PATIENTS AND METHODS

Patients from 10 international centres who underwent NAC for cT2-4aN0-1 MIBC and achieved <ypT2N0 disease at RC were included. The primary outcome was time to recurrence, either local or distant. Kaplan-Meier and Cox proportional hazards regression were used to evaluate associations between clinicopathological variables and outcomes.

RESULTS

A total of 625 patients were included. The median age was 66 years and 80% were male. Gemcitabine and cisplatin (GC, 56%) and methotrexate, vinblastine, doxorubicin and cisplatin (MVAC)/dose-dense (dd)MVAC (32%) were the most common NAC regimens. ypT0, pure ypTis, ypTa ±ypTis and ypT1 ± ypTis were attained in 58.1%, 20.0%, 7.6% and 14.2% of patients, respectively. The cumulative incidence of recurrence at 5 years was 9%, 16%, 29% and 30%, respectively. Pathological stage was prognostic for recurrence, with ypTa ± Tis (hazard ratio [HR] 3.20, 95% confidence interval [CI] 1.40-7.30) and ypT1 ± Tis disease (HR 4.03, 95% CI 2.13-7.63) associated with a significantly higher recurrence risk. Pure ypTis (HR 1.66, 95% CI 0.82-3.38) and the type of NAC regimen (ddMVAC: HR 1.59, 95% CI 0.55-4.56; MVAC: HR 1.18, 9%% CI 0.25-5.54; reference: GC) were not associated with recurrence.

CONCLUSION

We propose that optimal pathological response after NAC be defined as attainment of ypT0N0/ypTisN0 at RC. Patients with ypTaN0 or ypT1N0 disease (with or without Tis) at RC displayed a significantly higher risk of recurrence and may be candidates for trials investigating adjuvant therapy.

Efficacy of platinum re-challenge in metastatic urothelial carcinoma (mUC): A retrospective comparison of chemotherapy regimens

459

Background: First-line platinum-based combination chemotherapy (fPBC) is standard of care for fit patients with mUC. Further lines of therapy include immuno-oncology agents, erdafitinib, and enfortumab vedotin, but patients ineligible for these therapies or who subsequently progress may be considered for further chemotherapy. As the choice of chemotherapy regimen is unclear for these patients, we compared the efficacy of subsequent platinum-based chemotherapy (sPBC) and subsequent non-platinum-based chemotherapy (sNPBC) in patients with mUC. Methods: Data was analyzed from the Retrospective International Study of Cancers of the Urothelium (RISC), comprising patients from 28 international centers treated 2005-2012. Inclusion criteria were diagnosis of mUC, receipt of fPBC for mUC, and receipt of ≥2 cycles of subsequent chemotherapy. Patients who had received prior platinum-based chemotherapy in the non-metastatic setting were excluded. A multivariate Cox proportional hazards model was used to compare overall survival (OS), while χ2 and student’s t-test were used for univariate analyses. A two-sided p value of <0.05 was considered statistically significant. Results: Of 296 patients, 135 received sPBC and 161 received sNPBC. Common sNPBC regimens contained gemcitabine, taxanes, or pemetrexed. Baseline characteristics were similar, including Charlson Comorbidity Index (CCI) and performance status (PS), except more patients in the sPBC group had achieved investigator-designated stable disease or response (SD/R) with fPBC (75.4% vs. 63.3%, p = 0.031) and had higher hemoglobin values (median 11.9 vs. 11.1 g/dL, p = 0.004). OS was superior for patients receiving sPBC (median 7.9 months) compared to sNPBC (median 5.5 months) after adjusting for CCI, PS, presence of liver metastases, time since fPBC, and number of fPBC cycles received (HR 0.72, 95% CI 0.53-0.98, p = 0.035). 70 patients (57.4%) achieved SD/R with sPBC and 65 (44.8%) with sNPBC (p = 0.041). Achieving SD/R with subsequent chemotherapy was not associated with number of fPBC cycles received, but for sPBC was associated with longer time since fPBC (median 5.9 vs. 2.9 months, p = 0.033); the same was not true for sNPBC (median 2.2 vs. 2.6 months, p = 0.057). Achieving SD/R with fPBC was associated with greater likelihood of SD/R with sPBC (63.2% vs. 29.6%, p = 0.002), but not sNPBC (50.5% vs. 38.8%, p = 0.185). Liver metastases were negatively associated with likelihood of SD/R with sPBC (43.8% vs. 63.6%, p = 0.038), but not sNPBC (36.2% vs 49.0%, p = 0.147). Conclusions: After treatment with fPBC for mUC, patients able to receive sPBC had better OS compared to those who received sNPBC in a multivariate model. Patients were also more likely to achieve SD/R with sPBC; factors associated with achieving SD/R with sPBC but not sNPBC included longer interim since fPBC, achieving SD/R to fPBC, and absence of liver metastases.

Impact of timing of adjuvant chemotherapy following radical cystectomy for bladder cancer on patient survival

BACKGROUND

Trials of adjuvant chemotherapy following radical cystectomy generally require chemotherapy to start within 90 days postoperatively. However, it is unclear, whether the interval between surgery and start of adjuvant therapy (S-AC-interval) impacts the oncological outcome.

METHODS

Using the Retrospective International Study of Invasive/Advanced Cancer of the Urothelium (RISC) data base, we identified patients who underwent radical cystectomy for muscle invasive bladder cancer and subsequent adjuvant chemotherapy. Univariate analysis of patient characteristics, surgical factors and tumor characteristics regarding their impact on S-AC-interval was performed using Kruskal-Wallis testing and Fisher's exact test. Analysis of progression-free (PFS) and overall survival (OS) (follow-up time beginning with the start date of adjuvant chemotherapy) was analyzed in relation to S-AC-interval (continuous and dichotomous with a cut-off at 90 days) using Kaplan-Meier method and COX regression analysis.

RESULTS

We identified 238 eligible patients (83.5% male, mean age: 63.4 years, 76.1% T3/T4, 66.4% pN+, 14.7% R+, 70.6% urothelial carcinoma, 71% cisplatin-based adjuvant chemotherapy). The majority of patients (n = 207, 87%) started chemotherapy within 90 days after surgery. Median S-AC-interval was 57 days (interquartile range 32.8). S-AC-interval did not have consistent association with any patient/tumor characteristics or surgery related factors (type of surgery, urinary diversion). Survival analysis using continuous S-AC-interval revealed a trend toward an impact of S-AC-interval on OS (hazard ratio 1.004, 95% confidence ratio 0.9997-1.0084, P = 0.071). With regards to PFS, that impact was shown to be statistically significant (hazard ratio 1.004, 95% confidence ratio 1.0003-1.0075, P = 0.032). In multivariate analysis, however, S-AC-interval was negated by tumor and patient related factors (pathological T-stage, N-stage, ECOG performance status). Accounting for eligibility criteria defined in some clinical trials, we extended our analysis dividing S-AC-interval in ≤90 and >90 days. Although we could confirm the trend toward better outcome in patients with a shorter S-AC interval in dichotomous analysis, neither differences in OS nor in PFS reached statistical significance (P = 0.438 and P = 0.056).

CONCLUSIONS

In a large multi-institutional experience, 87% of patients who received adjuvant chemotherapy received it within the guideline recommended window of 90 days. While it was not possible to determine whether this is the optimal cut-off, early start of adjuvant chemotherapy seems to be reasonable. Regarding prognosis, tumor-related pathological factors abrogated the importance of the S-AC-interval in our analysis.

[Second-line treatment of metastatic urothelial carcinoma : Update immuno-oncology]

The approval of the PD‑1 and PD-L1 (programmed cell death [ligand] 1) antibodies pembrolizumab, nivolumab, and atezolizumab has fundamentally changed the therapeutic landscape of locally advanced or metastatic urothelial carcinoma. Checkpoint inhibitors (CPI) are the standard of care in second-line treatment if not already used in first line. They replace conventional chemotherapeutics such as vinflunine, paclitaxel, or docetaxel and offer a superior toxicity profile. This article provides an overview of current second-line treatment strategies for locally advanced or metastatic urothelial carcinoma.

Late toxicities and recurrences in patients with clinical stage I nonseminomatous germ cell tumor after one cycle of adjuvant BEP versus primary retroperitoneal lymph node dissection: A 13-years follow-up analysis of a phase III trial cohort

5512

Background: One cycle of adjuvant BEP has shown superiority in recurrence free survival over RPLND in patients (pts) with clinical stage (CS) I nonseminomatous germ cell tumor of the testis (NSGCT) (JCO 2008). We report recurrences and late toxicities of this randomized trial after 13 yrs of follow-up (FU). Methods: Questionnaires of 382 unselected pts with CS I NSGCT treated within a phase III trial comparing recurrence rate after 1 cycle of adjuvant BEP (arm A) vs. RPLND (arm B) were evaluated regarding recurrences and late toxicity. Overall (OS) and progression free survival (PFS) was calculated by Kaplan-Meier and arms were compared using logrank test. Categorial data were analyzed by chi-square test (PRISM v8). Results: In each arm 191 pts were analyzed as intention-to-treat with a median FU of 13.75 yrs (0-22.9 yrs); 3/191 pts (1.6 %) in arm A and 16/191 pts (8.4 %) in arm B had a recurrence. 20-yrs PFS in arm A / B was 97 % (CI 96-99 %) / 92 % (CI 90-95 %), ( p = .0049). 20-yrs OS in arm A / B was 90 % (CI 86-94 %) / 88 % (CI 86-94 %), ( p = .83). 23/382 (6 %) pts have died, 22/23 not related to testis cancer, 1/23 died of a recurrence in arm B. 8/191 pts (4.2 %) in arm A and 4/191 pts (2.1 %) in arm B showed metachronous secondary testis cancer ( p = .26). 5/191 pts (2.6 %) in arm A and 4/191 pts (2.1 %) in arm B developed other malignancies. 170/382 questionnaires were evaluable (arm A: 95; arm B: 75). 45 pts were lost to FU. There were no significant differences comparing both treatment arms regarding potentially treatment-related late toxicities. However, excluding pre-existing complaints, ototoxicity (9/95 (9 %) vs. 4/75 (5 %) pts, p = .31) was reported more frequently in arm A. Excluding pre-existing neurological conditions, peripheral neuropathy of all grades was more frequently reported in arm A (15/95 pts; 16 % vs. 9/75 pts; 12 % pts; p = .48). Retrograde ejaculation occurred more frequently after RPLND (9/95 pts; 9% vs. 18/75 pts; 24 %, p = .01). Conclusions: After more than 13 yrs of FU, recurrences in non-risk factor selected pts with CS I NSGCT remain to be significantly more frequent with RPLND. No excess mortality due to secondary malignancies was observed. Late toxicities did not differ between 1 cycle of BEP and RPLND. Only retrograde ejaculation was observed significantly more frequent after RPLND. With long-term observation, 1 cycle of BEP has not only a high efficacy to prevent recurrence but also seems to be tolerated without clinically relevant long-term toxicity.

Dissecting outcomes of patients (pts) with <ypT2N0 disease after neoadjuvant chemotherapy (NAC) for muscle invasive bladder cancer (MIBC): Results from a large, international, multicenter collaboration

5043

Background: Pathologic complete response (pCR) after NAC for MIBC is strongly correlated with long-term overall survival. However, there are sparse data on the risk of recurrence based on depth of pathologic response (pT0, pTa, pTis, pT1), and the differential impact of clinicopathologic factors and NAC regimen on recurrence. Methods: Baseline data on all pts with cT2-4N0-1 MIBC receiving NAC and who achieved < ypT2N0 disease at radical cystectomy (RC) from 9 international centers were obtained. The key outcome was time to recurrence (TTR) – defined as the time to any recurrence in the urinary tract or regional/distant metastasis, with death (in the absence of recurrence) considered a competing risk. Cox regression analysis was used to analyze the impact of clinical factors on recurrence. Results: A total of 506 pts were available. Median age was 66 years (range 33-86) and 78% (n = 396) were male; median follow-up after RC was 2.6 years. The majority of patients had pure urothelial histology (n = 371, 73%), and baseline stage was cT2N0 (n = 368, 73%), cT3-4N0 (n = 95, 19%) and TanyN1 (n = 43, 9%). NAC regimens were gemcitabine-cisplatin (GC, n = 296, 59%), dose-dense methotrexate-vinblastine-doxorubicin-cisplatin (ddMVAC, n = 141, 28%), split-dose GC (n = 29, 6%), MVAC (n = 29, 6%) and non-cisplatin based regimens (n = 11, 2%). At RC, 304 patients (60%) had ypT0N0 disease, 32 (6%) had ypTaN0, 107 (21%) had ypTisN0 and 63 (13%) had ypT1N0. Overall, 43 patients (8%) recurred with a median TTR of 56 weeks (range 7-251); 5-year freedom from recurrence was 87% (95% CI 83-91). The majority (n = 38) recurred outside the urinary tract. On multivariable analysis, ypTa (HR = 3.36 [1.24-9.11]) and ypT1 (HR = 2.88 [1.33-6.22], p = 0.013) disease at RC were predictors of shorter TTR, while female sex was associated with longer TTR (HR = 0.52 [0.27-0.98], p = 0.043). The type of NAC was not predictive of TTR (GC vs. other, HR = 1.49 [0.75-2.97], p = 0.26). Conclusions: To our knowledge, this is the largest study to quantify the risk of recurrence in pts achieving pathologic response after NAC and RC for MIBC. 8% of patients undergoing NAC and achieving < ypT2N0 at RC recurred. Residual ypTa and ypT1 disease conferred a significantly higher risk of recurrence, while ypTis did not; female sex was associated with a lower risk of recurrence. Importantly, the type of cisplatin-based NAC regimen used was not an independent predictor of recurrence.

Squamous-cell carcinoma variant histology (SCC-VH) in muscle-invasive bladder cancer (MIBC): A comprehensive clinical, genomic, and therapeutic assessment from multiple datasets

4535

Background: Pure or predominant SCC-VH is not uncommon in MIBC. Nevertheless, very few data are available about the efficacy of neoadjuvant chemotherapy (NAC). Here, we examined the outcomes after NAC, explored novel therapeutic targets, and propose new results in these patients (pts) by integrating multiple datasets. Methods: Within RISC and San Raffaele databases (1990-2018), we identified 2858 MIBC pts with urothelial cancer (UC, N = 2229) or VH (N = 629) who received RC +/- NAC. Kaplan-Meier and Cox regression analyses compared cancer-specific survival (CSS) between SCC and UC with NAC stratification. Logistic regression models tested the odds of clinical-to-pathological downstaging (cT > pT). Foundation Medicine (FMI) dataset was queried for SCC-VH. 97 pts were assayed with hybrid-capture based comprehensive genomic profiling (CGP). Finally, we looked at the results from the PURE-01 study, that is now amended and enrolling pts with VH (NCT02736266). Results: Overall, 127 (4.4%) had predominant SCC-VH, 157 (5.5%) UC+SCC. Among the NAC-treated pts, SCC was the only VH (N = 44) significantly associated with worse CSS, (p < 0.001) and higher mortality (HR 2.10, p = 0.003) vs. UC. After NAC adjustment, SCC-VH showed lower rate of downstaging (3.7 vs 9.3%, OR 0.4, p = 0.028) vs. UC. Similar negative trends were confirmed in pN0 pts, where SCC exhibited worse CSS (p = 0.006) and higher mortality (HR 5.15, p = 0.002). In the FMI cohort, the median tumor mutational burden (TMB) of SCC was 6.25 mut/mb (vs 6.9 mut/mb of 1984 UC), 27% of pts having > 10 mut/mb and 14% > 20 mut/mb. Clinically relevant alterations occurred in PIK3CA (42%), CCND1 (15%), PTEN (9.3%), FGFR3 (9.3%), and ERBB2 (6.2%). In the PURE-01 study, 13/84 (15.5%) SCC-VH pts received pembrolizumab before RC. PD-L1 combined positive score was ≥10 in 11/13 pts; results yielded 4 pT0 (30.8%), 10 pT≤1 (76.9%), and no deaths (median FUP: 10.4 mo). Conclusions: We present a comprehensive assessment of SCC-VH in MIBC. SCC represents the VH with the lowest activity of NAC. While CGP revealed multiple opportunities for targeted therapy, the efficacy of neoadjuvant pembrolizumab in SCC is encouraging.

Impact of timing of adjuvant chemotherapy following radical cystectomy for bladder cancer on patient survival

e16017

Background: Trials of adjuvant chemotherapy following radical cystectomy generally require chemotherapy to start approximately 90 days postoperatively. However, it is unclear, whether the interval between surgery and start of adjuvant therapy (S-AC-interval) impacts the oncological outcome. Methods: Using the Retrospective International Study of Invasive/Advanced Cancer of the Urothelium (RISC) data base, we identified patients who underwent radical cystectomy for muscle invasive bladder cancer and subsequent adjuvant chemotherapy. Uni- and multi-variate analysis of patient characteristics, surgical factors and tumor characteristics regarding their impact on S-AC-interval was performed. Uni- and multivariate analysis of progression-free and overall survival (starting from day 1 of adjuvant chemotherapy) was analysed in relation to SAC interval (both continuous and dichotomous with a cut-off at 90 days), patient characteristics, surgical factors and tumor characteristics by Kaplan-Meier and COX regression analysis. Results: Two hundred thirty-eight eligible patients were identified (83% male, median age: 64 years, 76% T3/T4, 66% pN+, 15% R+, 75% urothelial carcinoma, 71% cisplatin-based adjuvant chemotherapy). Median S-AC-interval was 57 days (range 10-321 days, ≤ 90 days: 87%, 91-120 days: 6%, > 120 days: 7%). S-AC-interval did not have association with any patient/tumor characteristics or surgery related factors (type of surgery, diversion). S-AC-interval did not impact patients´ outcomes when adjuvant chemotherapy was initiated 90 days after surgery. Median PFS and OS in patients with an S-AC-interval of 90 days was 37 and 73 months, respectively, as compared to 24 and 48 months in patients with an S-AC-interval > 90 days. Only differences in PFS reached statistical significance (37 (95% CI 26-48) months vs. 24 (95% CI 12-36) months p = .042; Log Rank test). When analyzed by different multivariate models, the impact of S-AC-interval on PFS and OS was negated by tumor related factors (pathological T-stage and N-stage). Conclusions: An S-AC-interval of below 90 days is likely to be optimal in bladder cancer patients requiring adjuvant therapy. However, regarding prognosis, tumor related pathological factors seem to be more important than the S-AC-interval.

5-factor prognostic model for survival of patients with metastatic urothelial carcinoma receiving three different post-platinum PD-L1 inhibitors

4552

Background: A prognostic model for overall survival (OS) of metastatic urothelial carcinoma (mUC) was previously reported in the setting of post-platinum atezolizumab (Pond GR, GU ASCO 2018). This model was limited by employing only atezolizumab treated patients (pts), small size of the validation dataset and unclear applicability to other PD-1/L1 inhibitors. Hence, we constructed a robust prognostic model utilizing the combined atezolizumab cohort as the discovery dataset and used 2 separate validation datasets comprised of post-platinum avelumab or durvalumab treated pts. Methods: The discovery dataset consisted of pt level data from 2 phase I/II trials (IMvigor210 and PCD4989g) evaluating atezolizumab (n = 405). Pts enrolled on 2 separate phase I/II trials, EMR 100070-001 that evaluated post-platinum avelumab (n = 242) and CD1108 that evaluated durvalumab (n = 189) comprised the validation datasets. Cox regression analyses evaluated the association of candidate prognostic factors with OS. Factors were dichotomized and laboratory values were normalized by logarithmic transformation. Stepwise selection was employed to propose an optimal model using the discovery dataset. Discrimination and calibration were assessed in the avelumab and durvalumab datasets following the validation procedure by Royston and Altman (2013). Results: The 5 factors included in the optimal prognostic model in the discovery dataset were ECOG-PS (1 vs. 0; HR 1.80; 95% CI [1.36-2.36]), presence/absence of liver metastasis (HR 1.55; 95% CI [1.20-2.00]), number of platelets (HR 2.22; 95% CI [1.54-3.18]), neutrophil-lymphocyte ratio (NLR; HR 1.94; 95% CI [1.57-2.40]) and lactate dehydrogenase (LDH; HR 1.60; 95% CI [1.28-1.99]). There was robust discrimination of survival between low, intermediate and high-risk groups based on 0-1, 2-3 and 4 factors. The concordance of survival was 0.692 in the discovery and 0.671 and 0.775 in the avelumab and durvalumab validation datasets, respectively. Acceptable or good calibration of expected 1-year survival rate was observed. Conclusions: A 5-factor prognostic model is prognostic for survival across 3 different PD-L1 inhibitors (atezolizumab, avelumab, durvalumab) in this large study totaling 836 pts overall in the setting of post-platinum therapy for mUC. This model may assist in prognostic stratification and interpreting nonrandomized trials of post-platinum PD1/L1 inhibitors.

The Impact of Cisplatin- or Non-Cisplatin-Containing Chemotherapy on Long-Term and Conditional Survival of Patients with Advanced Urinary Tract Cancer

BACKGROUND

The impact of cisplatin use on long-term survival of unselected patients with advanced urinary tract cancer (aUTC) has not been adequately investigated. We used a multinational database to study long-term survival and the impact of treatment type in unselected patients with aUTC.

MATERIALS AND METHODS

A total of 1,333 patients with aUTC (cT4bN0M0, cTanyN+M0, cTanyNanyM+), transitional-cell, squamous, or adenocarcinoma histology who received systemic chemotherapy and had available survival data were selected. Long-term survival was defined as alive at 3 years following initiation of first-line chemotherapy. Conditional overall survival (COS) analysis was employed to study change in prognosis given time survived from initiation of first-line chemotherapy.

RESULTS

Median follow-up was 31.7 months. The combination of cisplatin use and cisplatin eligibility accurately predicted long-term survival. Eligible patients treated with cisplatin conferred a 31.6% probability of 3-year survival (95% confidence interval [CI]: 25.1-38.3), and 2-year COS for patients surviving 3 years after initiation of cisplatin-based chemotherapy was 83% (95% CI: 59.7-93.5). The respective probabilities for patients who were ineligible for cisplatin or not treated with cisplatin despite eligibility were 14% (95% CI: 10.8-17.6) and 49.3% (95% CI: 28.2-67.4). Two-year COS remained significantly different between these two groups up to 3 years after chemotherapy initiation.

CONCLUSION

Cisplatin-based therapy was associated with the highest likelihood of long-term survival in patients with aUTC and should be used in patients who fulfill the established eligibility criteria. Novel therapies are necessary to increase long-term survival in cisplatin-ineligible patients.

IMPLICATIONS FOR PRACTICE

Long-term, disease-free survival is possible in one in four eligible-for-cisplatin patients with advanced urinary tract cancer (aUTC) treated with cisplatin-based combination chemotherapy. Therefore, deviations from eligibility criteria should be avoided. Consolidation surgery should be considered in responders. These data provide benchmarks for the study of novel therapies in aUTC.

Impact of contemporary patterns of chemotherapy utilization on survival in patients with advanced cancer of the urinary tract: a Retrospective International Study of Invasive/Advanced Cancer of the Urothelium (RISC)

Background

Cisplatin-based combination chemotherapy is the standard treatment of advanced urinary tract cancer (aUTC), but 50% of patients are ineligible for cisplatin according to recently published criteria. We used a multinational database to study patterns of chemotherapy utilization in patients with aUTC and determine their impact on survival.

Patients and methods

This was a retrospective study of patients with: UTC (bladder, renal pelvis, ureter or urethra); advanced disease (stages T4b and/or N+ and/or M+); urothelial, squamous or adenocarcinoma histology. Primary objective was overall survival (OS). Eligibility-for-cisplatin was defined by Eastern Cooperative Oncology Group performance status ≤ 1, creatinine clearance ≥ 60 ml/min, no hearing loss, no neuropathy and no heart failure. Cox regression multivariate analyses were used to establish independent associations of cisplatin versus noncisplatin-based chemotherapy on OS.

Results

1794 patients treated between 2000 and 2013 at 29 centers were analyzed. Median follow-up was 29.1 months. About 1333 patients (74%) received first-line chemotherapy: the use of first-line chemotherapy was associated with longer OS: [hazard ratio (HR): 1.91, 95% confidence interval (CI): 1.67-2.20]. Type of first-line chemotherapy received was: cisplatin-based 669 (50%), carboplatin-based 399 (30%) and other 265 (20%). Cisplatin use was an independent favorable prognostic factor (HR: 1.54, 95% CI: 1.35-1.77). This benefit was independent of baseline characteristics or comorbidities but was associated with eligibility-for-cisplatin: eligible patients treated with cisplatin lived longer than those who were not (HR: 1.74, 95% CI: 1.36-2.21), while such benefit was not observed among ineligible patients. About 26% of patients who did not receive cisplatin were eligible for this agent. Median OS of ineligible patients was poor irrespective of the chemotherapy used.

Conclusions

The importance of applying published criteria of eligibility-for-cisplatin was confirmed in a multinational, real-world setting in aUTC. The reasons for deviations from these criteria set targets to improve adherence. Effective therapies for cisplatin-ineligible patients are needed.

Validated five-factor prognostic model for survival of patients (pts) with metastatic urothelial carcinoma (mUC) receiving different post-platinum PD-L1 inhibitors

476

Background: A prognostic model for overall survival (OS) of mUC was previously reported in the setting of post-platinum atezolizumab (Pond GR, GU ASCO 2018). This model was limited by employing only atezolizumab treated pts, small size of the validation dataset and unclear applicability to other PD-1/L1 inhibitors. Hence, we constructed a robust prognostic model utilizing the combined atezolizumab cohort as the discovery dataset and used a validation dataset comprised of post-platinum avelumab-treated pts. Methods: The discovery dataset consisted of pt level data from 2 phase I/II trials (IMvigor210 and PCD4989g) evaluating atezolizumab (n = 405). Pts enrolled on a phase I/II trial that received post-platinum avelumab (n = 242) comprised the validation dataset (EMR 100070-001). Cox regression analyses evaluated the association of candidate prognostic factors with OS. Factors were dichotomized and laboratory values were normalized by logarithmic transformation. Stepwise selection was employed to propose an optimal model using the discovery dataset. Discrimination (via c-statistic) and calibration were assessed in the avelumab dataset following the validation procedure by Royston and Altman (2013). Results: The 5 factors included in the optimal prognostic model in the discovery dataset were ECOG-PS (1 vs. 0; HR 1.80; 95% CI [1.36-2.36]), presence/absence of liver metastasis (HR 1.55; 95% CI [1.20-2.00]), number of platelets (HR 2.22; 95% CI [1.54-3.18]), neutrophil-lymphocyte ratio (NLR; HR 1.94; 95% CI [1.57-2.40]) and lactate dehydrogenase (LDH; HR 1.60; 95% CI [1.28-1.99]). The c-statistic for prediction of survival was 0.692 and 0.671 in the discovery and validation datasets, respectively. Acceptable or good calibration of expected 1-year survival was observed. Conclusions: A 5-factor externally validated prognostic model for OS is proposed employing a large dataset of 647 pts overall in the setting of post-platinum PD-L1 inhibitors for mUC. This model may assist in prognostic stratification and interpreting nonrandomized trials of post-platinum PD1/L1 inhibitors.

Impact of the Number of Cycles of Platinum Based First Line Chemotherapy for Advanced Urothelial Carcinoma

PURPOSE

We evaluated the impact of the number of cycles of platinum based, first line chemotherapy (fewer than 6 cycles vs the conventional 6 cycles or more) on the survival of patients with metastatic urothelial carcinoma.

MATERIALS AND METHODS

We used the RISC (Retrospective International Study of Invasive/Advanced Cancer of the Urothelium) database. The association of the number of cycles of chemotherapy with overall survival was investigated by Cox multiple regression analysis after controlling for recognized prognostic factors. We excluded patients who received fewer than 3 or more than 9 platinum chemotherapy cycles to reduce confounding factors. The primary analysis was a comparison of overall survival for 3 to 5 vs 6 to 9 cycles using 6-month landmark analysis when 281 death events were observed.

RESULTS

Of the 1,020 patients in the RISC 472 received cisplatin or carboplatin, of whom 338 and 134, respectively, were evaluable. A total of 157 patients received 3 to 5 cycles (median 4) and 315 received 6 to 9 cycles (median 6). There was no significant difference in overall survival between 3 to 5 and 6 to 9 cycles (HR 1.02, 95% CI 0.78-1.33, p = 0.91). No significant interactions were observed for the type of platinum (p = 0.09) and completed planned chemotherapy (p = 0.56). The limitations of a hypothesis generating, retrospective analysis applied.

CONCLUSIONS

Four cycles of platinum based, first line chemotherapy appeared adequate and did not significantly compromise the survival of patients with advanced urothelial carcinoma. The omission of excessive cycles may avoid unnecessary cumulative toxicity and facilitate a better transition to second line therapy and investigational switch maintenance therapy strategies. These results require prospective validation but they may impact practice in select patients.

Radical cystectomy or bladder preservation with radiochemotherapy in elderly patients with muscle-invasive bladder cancer: Retrospective International Study of Cancers of the Urothelial Tract (RISC) Investigators

BACKGROUND

Radical cystectomy (RC) and radiochemotherapy (RCT) are curative options for muscle-invasive bladder cancer (MIBC). Optimal treatment strategy remains unclear in elderly patients.

MATERIAL AND METHODS

Patients aged 80 years old and above with T2-T4aN0-2M0-Mx MIBC were identified in the Retrospective International Study of Cancers of the Urothelial Tract (RISC) database. Patients treated with RC were compared with those treated with RCT. The impact of surgery on overall survival (OS) was assessed using a Cox proportional hazard model. Progression included locoregional and metastatic relapse and was considered a time-dependent variable.

RESULTS

Between 1988 and 2015, 92 patients underwent RC and 72 patients had RCT. Median age was 82.5 years (range 80-100) and median follow-up was 2.90 years (range 0.04-11.10). Median OS was 1.99 years (95%CI 1.17-2.76) after RC and 1.97 years (95%CI 1.35-2.64) after RCT (p = .73). Median progression-free survival (PFS) after RC and RCT were 1.25 years (95%CI 0.80-1.75) and 1.52 years (95%CI 1.01-2.04), respectively (p = .54). In multivariate analyses, only disease progression was significantly associated with worse OS (HR = 10.27 (95%CI 6.63-15.91), p < .0001). Treatment modality was not a prognostic factor.

CONCLUSIONS

RCT offers survival rates comparable to those observed with RC for patients aged ≥80 years.

New 6-factor prognostic model for patients (pts) with advanced urothelial carcinoma (UC) receiving post-platinum atezolizumab

413

Background: Prognostic factors for overall survival (OS) have been identified in pts receiving post-platinum chemotherapy for advanced UC, but it is unknown whether these factors and/or others optimally predict OS for pts treated with PD1/PD-L1 inhibitor therapy. Methods: Pt level data from two UC salvage trials evaluating atezolizumab were used: IMvigor210 (n = 310) for training and PCD4989g (n = 95) for validation. Univariable and multivariable Cox regression analyses were performed to evaluate the association of the prognostic factors recognized in the chemotherapy setting (ECOG performance status [ECOG-PS], liver metastasis (LM), anemia, treatment-free interval, albumin), neutrophil-lymphocyte ratio (NLR), eosinophil count, platelet count (PLT), site of primary/metastases, stage at diagnosis, smoking, LDH, prior therapies and immune cell PD-L1 status by IHC with OS. Clinical factors were dichotomous and lab values normalized by logarithmic transformation as needed. Stepwise selection was employed to propose an optimal model using the training dataset; pts were then categorized by number of risk factors. Concordance, discrimination (c-statistic) and calibration were assessed in the validation dataset using bootstrap analyses. Results: The factors included in the optimal prognostic model for OS were: ECOG-PS 1 vs. 0 (HR 1.64 [95% CI: 1.20, 2.24], p = 0.002), LM (1.45 [1.08, 1.94], p = 0.014), PLT (1.73 [1.14, 2.61], p = 0.010), NLR (1.84 [1.45, 2.34], p < 0.001), LDH (1.54 [1.19, 1.99], p = < 0.001) and anemia (HR = 1.60 [1.17, 2.21] p = 0.004). The c-statistic was 0.690 (95% CI = 0.649-0.715) and 0.759 (0.694-0.795) in the training and validation datasets, respectively. 1-year OS of pts in the training and the validation cohorts were similar. PD-L1 score was statistically significant when adjusted for the optimal model, but did not improve clinical interpretability (c-statistic = 0.698). Conclusions: A new validated 6-factor prognostic model for OS including ECOG-PS, LM, PLT, NLR, LDH and anemia is proposed in the setting of post-platinum atezolizumab for advanced UC. Applicability of the model to other PD1/PD-L1 inhibitors and PD-L1 IHC assays warrant investigation.

Nomogram-based risk prediction of local and distant relapse after radical cystectomy, and role of perioperative chemotherapy, in patients with muscle-invasive bladder cancer (MIBC): A multicenter study

448

Background: Neoadjuvant and adjuvant chemotherapy improve relapse-free survival (RFS) and overall survival of patients (pts) with MIBC. Limited information is available regarding risk prediction of local (RL) vs. distant relapse (RD), including role of perioperative chemotherapy (POC), added to radical cystectomy (Cy). Methods: Data from 1,559 pts, treated at 29 centers from the U.S., Europe, Israel, and Canada, were collected. Pts received Cy for MIBC from 02/90 to 12/13. Of these pts, 782 (50.2%) received POC and Cy, 777 (49.8%) Cy alone. RL and RD were defined as follows: pelvic lymph-nodes/soft tissue only and any extra-pelvic recurrences, respectively. Cumulative incidence methods were used to estimate time-to-(TT) RL/RD, which accounts for the competing risk of other types of relapse. Univariable and multivariable (MVA) Cox regression analyses were performed from the complete-case dataset (n = 1,082). Risk groups were defined according to the number of adverse factors, with corresponding nomogram-based RL and RD risk estimation. All tests were two-sided and statistical significance was defined as a p-value of 0.05 or less. Results: A total of 830 pts (55%) developed a relapse, 447 in the Cy group and 383 in the Cy+POC group. On MVA, POC administration was associated with longer TTRL (p < 0.001) and TTRD (p < 0.001). Other factors associated with RL: histology (non-UC, odds ratio [OR] = 1.47, 95%CI: 1.07-2.01, p = 0.022), pT-stage (p < 0.001), pN-stage (p = 0.038), surgical margins (p < 0.001). For RD: Charlson score (p = 0.006), pT-stage (p < 0.001), pN-stage (p < 0.001). The c-index of the model for RL was 0.685 (95% bootstrapped CI: 0.664-0.718), and for RD was 0.684 (0.655-0.721). Three risk group categories were obtained for both endpoints (0, 1-2, and > 2 risk factors). Results were confirmed after applying 90-day or 180-day landmark analyses, pending external validation. Conclusions: In the largest study that separately analyzed RL and RD risk, we were able to provide risk tools that may be used to optimize locoregional treatments and compare POC benchmark with new drugs in the perioperative setting.

Impact of number of cycles of platinum-based first-line chemotherapy for advanced urothelial carcinoma

426

Background: 6 cycles of platinum-based chemotherapy (CT) are conventionally targeted to treat locally advanced unresectable or metastatic urothelial carcinoma (UC). However, cisplatin is associated with significant cumulative toxicities, which render it challenging to deliver 6 cycles. Since this issue has not been investigated prospectively, we conducted a retrospective analysis. Methods: The Retrospective International Study of Invasive/Advanced Cancer of the Urothelium (RISC) database was used to conduct a retrospective analysis. The association of the number of cycles of platinum-based first-line CT with overall survival (OS) was investigated by a Cox regression utilizing multivariate analysis after controlling for previously recognized prognostic factors used in a nomogram ( Eur Urol, 2017). The primary analysis was a comparison of < 6 cycles vs. ≥6 cycles. Six-month landmark analysis was applied throughout, accounting for OS events. Additionally, we excluded patients (pts) receiving < 3 or > 9 cycles to reduce confounding due to early removal for toxicities, progression and patient decision and increased number of cycles due to response and pt-related factors. Results: Of 1020 pts available from RISC, 472 (cisplatin = 338, carboplatin = 134) were evaluable for the landmark analysis with 281 events. A total of 157 pts received 3-5 cycles (median 4) and 315 received 6-9 cycles (median 6). There was no significant difference between 3-5 vs. 6-9 cycles of platinum-based chemotherapy (HR 1.02, 95%CI: 0.77-1.33, p = 0.91). No significant interactions were observed with type of platinum (p = 0.09) and “completed planned CT” (p = 0.56). Comparison of 4 vs. 6 cycles (p = 0.57) and < 6 vs 6 vs 7-9 (p = 0.9) also yielded no significant differences for association with OS. No differential association was observed with survival for 3-5 vs. 6-9 cycles when examining by nomogram-defined risk group tertiles. Limitations of a hypothesis-generating retrospective analysis apply. Conclusions: 4 cycles of platinum based first-line CT appear adequate to treat advanced UC. The omission of excessive cycles will avoid unnecessary toxicities and facilitate better transition to second-line and switch maintenance therapy.

Venous Thromboembolism Risk in Patients With Locoregional Urothelial Tract Tumors

BACKGROUND

Venous thromboembolism (VTE) is common in cancer patients, but there is limited data on patients with urothelial tract tumors (UTT). We previously identified several associative factors for increased VTE rates in patients with metastatic UTT. In this study, we assessed the frequency, associative factors, and impact on survival of VTE in patients with locoregional UTT.

METHODS

Patients with locoregional bladder, upper urinary tract, or urethral cancer were included in this multi-center study from 29 academic institutions. Patients with < cT2, > N1, or M1 disease at diagnosis were excluded. Patients with incomplete clinical staging or miscoded/missing data were excluded. Cumulative, unadjusted VTE incidence was calculated from time of diagnosis of muscle-invasive disease, excluding VTEs diagnosed in the metastatic setting. χ2 statistics tested differences in VTE rates across baseline and treatment-related factors. Significant covariates were incorporated into a multivariate, logistic regression model. Overall survival stratified by VTE was estimated using Kaplan-Meier methods and evaluated using the log-rank test.

RESULTS

A total of 1732 patients were eligible. There were 132 (7.6%) VTEs. On multivariate analysis, non-urothelial histology (P < .001), clinical Nx stage (P < .001), cardiovascular disease (P = .01), and renal dysfunction (P = .04) were statistically significant baseline factors associated with VTE. Using surgery alone as reference, surgery with perioperative chemotherapy (P = .04) and radiation with concurrent chemotherapy (P = .04) also were significant.

CONCLUSIONS

The VTE incidence of 7.6% in locoregional disease is comparable with our previously reported rate in the metastatic setting (8.2%). Similar to our findings in metastatic UTT, non-urothelial histology, renal dysfunction, and CVD was associated with increased VTE risk.

Lack of Effectiveness of Postchemotherapy Lymphadenectomy in Bladder Cancer Patients with Clinical Evidence of Metastatic Pelvic or Retroperitoneal Lymph Nodes Only: A Propensity Score-based Analysis

BACKGROUND

Limited data is available on the role, and extent of, postchemotherapy lymphadenectomy (PC-LND) in patients with clinical evidence of pelvic (cN1-3) or retroperitoneal (RP) lymph node spread from urothelial bladder carcinoma.

OBJECTIVE

To compare the outcomes of operated versus nonoperated patients after first-line chemotherapy.

DESIGN, SETTING, AND PARTICIPANTS

Data from 34 centers was collected, totaling 522 patients, treated between January 2000 and June 2015. Criteria for patient selection were the following: bladder primary tumor, lymph node metastases (pelvic±RP) only, first-line platinum-based chemotherapy given.

INTERVENTION

LND (with cystectomy) versus observation after first-line chemotherapy for metastatic urothelial bladder carcinoma.

OUTCOME MEASURES AND STATISTICAL ANALYSIS

Overall survival (OS) was the primary endpoint. Multiple propensity score techniques were adopted, including 1:1 propensity score matching and inverse probability of treatment weighting. Additionally, the inverse probability of treatment weighting analysis was performed with the inclusion of the covariates, that is, with doubly robust estimation.

RESULTS AND LIMITATIONS

Overall, 242 (46.4%) patients received PC-LND and 280 (53.6%) observation after chemotherapy. There were 177 (33.9%) and 345 (66.1%) patients with either RP or pelvic LND only, respectively. Doubly robust estimation-adjusted comparison was not significant for improved OS for PC-LND (hazard ratio [HR]: 0.86, 95% confidence interval [CI]: 0.56-1.31, p=0.479), confirmed by matched analysis (HR: 0.91, 95% CI: 0.60-1.36, p=0.628). This was also observed in the RP subgroup (HR: 1.12, 95% CI: 0.68-1.84). The retrospective nature of the data and the heterogeneous patient population were the major limitations.

CONCLUSIONS

Although there were substantial differences between the two groups, after accounting for major confounders we report a nonsignificant OS difference with PC-LND compared with observation only. These findings may be hypothesis-generating for future prospective trials.

PATIENT SUMMARY

We found no differences in survival by adding postchemotherapy lymphadenectomy in patients with pelvic or retroperitoneal lymph node metastatic bladder cancer. The indication to perform postchemotherapy lymphadenectomy in the most suitable patients requires additional studies.

Atezolizumab (atezo) in platinum-treated locally advanced or metastatic urothelial carcinoma (mUC): Outcomes by prior therapy

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Background: Atezo is approved in the US for mUC and non-small cell lung cancer after prior treatment with chemotherapy. > 40% of mUC pts in the Phase 2 IMvigor210 study received ≥ 2prior metastatic regimens (Rosenberg, Lancet 2016). This analysis was performed to assess the impact of prior therapy on atezo outcomes in mUC. Methods: mUC pts in the platinum-pretreated IMvigor210 cohort (NCT02108652) received atezo 1200 mg IV q3w until loss of clinical benefit. Study endpoints analyzed by the number of prior treatment regimens included RECIST v1.1 ORR (central review), complete response (CR) rate, median durations of response (mDOR) and survival (mOS) and adverse event rate. Results: Evaluable pts (N = 310) had a median age of 66 years, and 78% had visceral mets (31% liver). 82% of pts had prior systemic treatment for mUC; number of prior regimens ranged from 1 to ≥ 4 (Table). 73% of pts received prior cisplatin, and 26% had carboplatin (no cisplatin). Objective responses, including CRs, occurred regardless of the number of prior therapies and were ongoing in 65% of responders at the July 4, 2016 data cut off (median follow-up, 21 mo [range, 0.2+-24.5]). mDOR was not reached in any subgroup based on number of treatments, except in pts who received only perioperative chemotherapy (mDOR, 16 mo [95% CI: 6.2, NE]). Similarly, mOS was generally consistent despite number of prior regimens (Table). Atezo remained generally well tolerated with similar overall safety and tolerability by line of therapy. Conclusions: Clinically meaningful benefit was observed in pts treated with atezo notwithstanding number of prior systemic mUC regimens. Minimally and heavily pre-treated pts had durable responses, encouraging OS and no major differences in safety signals. Clinical trial information: NCT02108652. [Table: see text]

Venous thromboembolism in metastatic urothelial carcinoma or variant histologies: incidence, associative factors, and effect on survival

Venous thromboembolism (VTE) is common in cancer patients. However, little is known about VTE risk in metastatic urothelial carcinoma or variant histologies (UC/VH). We sought to characterize the incidence, associative factors, including whether various chemotherapy regimens portend different risk, and impact of VTE on survival in metastatic UC/VH patients. Patients diagnosed with metastatic UC/VH from 2000 to 2013 were included in this multicenter retrospective, international study from 29 academic institutions. Cumulative and 6‐month VTE incidence rates were determined. The association of first‐line chemotherapy (divided into six groups) and other baseline characteristics on VTE were analyzed. Each chemotherapy treatment group and statistically significant baseline clinical characteristics were assessed in a multivariate, competing‐risk regression model. VTE patients were matched to non‐VTE patients to determine the impact of VTE on overall survival. In all, 1762 patients were eligible for analysis. There were 144 (8.2%) and 90 (5.1%) events cumulative and within the first 6 months, respectively. VTE rates based on chemotherapy group demonstrated no statistical difference when gemcitabine/cisplatin was used as the comparator. Non‐urotheilal histology (SHR: 2.67; 95% CI: 1.72–4.16, P < 0.001), moderate to severe renal dysfunction (SHR: 2.12; 95% CI: 1.26–3.59, P = 0.005), and cardiovascular disease (CVD) or CVD risk factors (SHR: 2.27; 95% CI: 1.49–3.45, P = 0.001) were associated with increased VTE rates. Overall survival was worse in patients with VTE (median 6.0 m vs. 10.2 m, P < 0.001). Thus, in metastatic UC/VH patients, VTE is common and has a negative impact on survival. We identified multiple associated potential risk factors, although different chemotherapy regimens did not alter risk.

Patterns of Bladder Preservation Therapy Utilization for Muscle-Invasive Bladder Cancer

Background: Trimodality bladder preservation therapy (BPT) in muscle invasive bladder cancer (MIBC) includes a maximal transurethral resection followed by concurrent chemoradiotherapy as an alternative to radical cystectomy (RC) in appropriately selected patients, or as a treatment option in non-cystectomy candidates. Several chemotherapy regimens can be used in BPT, but little is known about current practice patterns. Objective: To describe utilization patterns of BPT and associated survival outcomes in MIBC. Methods: Data were collected from the Retrospective International Study of Cancers of the Urothelial Tract (RISC), a database of 3,024 consecutive patients from 29 international academic centers from 2005 to 2013. Patients with clinical T2-T4aN0M0 urothelial cancer of the bladder were included. Results: 265 patients received BPT. Compared with the 1,447 patients who received RC, BPT patients were older, had poorer performance status, and had more comorbidities (p < 0.01 for all). Median overall survival (OS) was similar for patients treated with curative radiation doses in BPT and patients treated with RC (41 vs 46 months, p = 0.33, respectively). 45% of BPT patients received concurrent chemotherapy with radiation. The most common regimens included cisplatin alone (23%), carboplatin alone (22%), gemcitabine alone (10%), paclitaxel alone (9%), and 5-FU+mitomycin (5%). There were no significant differences in survival among chemotherapy regimens. Only 10 patients (4% of BPT patients) underwent salvage cystectomy. Conclusions: In clinical practice, BPT patients have similar survival to RC patients when treated with curative radiotherapy doses. Choice of concurrent chemotherapy regimen varied widely with no clear standard. Salvage cystectomy is rarely performed. Continued research is needed on the comparative effectiveness among BPT and RC, and among chemotherapy regimens in BPT.