Elisabeth E. Fransen van de Putte

Impact of Molecular Subtypes in Muscle-invasive Bladder Cancer on Predicting Response and Survival after Neoadjuvant Chemotherapy

BACKGROUND An early report on the molecular subtyping of muscle-invasive bladder cancer (MIBC) by gene expression suggested that response to neoadjuvant chemotherapy (NAC) varies by subtype. OBJECTIVE To investigate the ability of molecular subtypes to predict pathological downstaging and survival after NAC. DESIGN, SETTING, AND PARTICIPANTS Whole transcriptome profiling was performed on pre-NAC transurethral resection specimens from 343 patients with MIBC. Samples were classified according to four published molecular subtyping methods. We developed a single-sample genomic subtyping classifier (GSC) to predict consensus subtypes (claudin-low, basal, luminal-infiltrated and luminal) with highest clinical impact in the context of NAC. Overall survival (OS) according to subtype was analyzed and compared with OS in 476 non-NAC cases (published datasets). INTERVENTION Gene expression analysis was used to assign subtypes. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Receiver-operating characteristics were used to determine the accuracy of GSC. The effect of GSC on survival was estimated by Cox proportional hazard regression models. RESULTS AND LIMITATIONS The models generated subtype calls in expected ratios with high concordance across subtyping methods. GSC was able to predict four consensus molecular subtypes with high accuracy (73%), and clinical significance of the predicted consensus subtypes could be validated in independent NAC and non-NAC datasets. Luminal tumors had the best OS with and without NAC. Claudin-low tumors were associated with poor OS irrespective of treatment regimen. Basal tumors showed the most improvement in OS with NAC compared with surgery alone. The main limitations of our study are its retrospective design and comparison across datasets. CONCLUSIONS Molecular subtyping may have an impact on patient benefit to NAC. If validated in additional studies, our results suggest that patients with basal tumors should be prioritized for NAC. We discovered the first single-sample classifier to subtype MIBC, which may be suitable for integration into routine clinical practice. PATIENT SUMMARY Different molecular subtypes can be identified in muscle-invasive bladder cancer. Although cisplatin-based neoadjuvant chemotherapy improves patient outcomes, we identified that the benefit is highest in patients with basal tumors. Our newly discovered classifier can identify these molecular subtypes in a single patient and could be integrated into routine clinical practice after further validation.

ERBB2 Mutations Characterize a Subgroup of Muscle-invasive Bladder Cancers with Excellent Response to Neoadjuvant Chemotherapy

UNLABELLED A pathologic complete response to neoadjuvant chemotherapy (NAC) containing platinum is a strong prognostic determinant for patients with muscle-invasive bladder cancer (MIBC). Despite comprehensive molecular characterization of bladder cancer, associations of molecular alterations with treatment response are still largely unknown. We selected pathologic complete responders (ypT0N0; n=38) and nonresponders (higher than ypT2; n=33) from a cohort of high-grade MIBC patients treated with NAC. DNA was isolated from prechemotherapy tumor tissue and used for next-generation sequencing of 178 cancer-associated genes (discovery cohort) or targeted sequencing (validation cohort). We found that 9 of 38 complete responders had erb-b2 receptor tyrosine kinase 2 (ERBB2) missense mutations, whereas none of 33 nonresponders had ERBB2 mutations (p=0.003). ERBB2 missense mutations in complete responders were mostly confirmed activating mutations. ERCC2 missense mutations, recently found associated with response to NAC, were more common in complete responders; however, this association did not reach statistical significance in our cohort. We conclude that ERBB2 missense mutations characterize a subgroup of MIBC patients with an excellent response to NAC. PATIENT SUMMARY In this report we looked for genetic alterations that can predict the response to neoadjuvant chemotherapy (NAC) in bladder cancer. We found that mutations in the gene ERBB2 are exclusively present in patients responding to NAC.

Incidence, Characteristics and Implications of Thromboembolic Events in Patients with Muscle Invasive Urothelial Carcinoma of the Bladder Undergoing Neoadjuvant Chemotherapy

PURPOSE Neoadjuvant chemotherapy and pelvic surgery are significant risk factors for thromboembolic events. Our study objectives were to investigate the timing, incidence and characteristics of thromboembolic events during and after neoadjuvant chemotherapy and subsequent radical cystectomy in patients with muscle invasive bladder cancer. MATERIALS AND METHODS We performed a multi-institutional retrospective analysis of 761 patients who underwent neoadjuvant chemotherapy and radical cystectomy for muscle invasive bladder cancer from 2002 to 2014. Median followup from diagnosis was 21.4 months (range 3 to 272). Patient characteristics included the Khorana score, and the incidence and timing of thromboembolic events (before vs after radical cystectomy). Survival was calculated using the Kaplan-Meier method. The log rank test and multivariable Cox proportional hazards regression were used to compare survival between patients with vs without thromboembolic events. RESULTS The Khorana score indicated an intermediate thromboembolic event risk in 88% of patients. The overall incidence of thromboembolic events in patients undergoing neoadjuvant chemotherapy was 14% with a wide variation of 5% to 32% among institutions. Patients with thromboembolic events were older (67.6 vs 64.6 years, p = 0.02) and received a longer neoadjuvant chemotherapy course (10.9 vs 9.7 weeks, p = 0.01) compared to patients without a thromboembolic event. Of the thromboembolic events 58% developed preoperatively and 72% were symptomatic. On multivariable regression analysis the development of a thromboembolic event was not significantly associated with decreased overall survival. However, pathological stage and a high Khorana score were adverse risk factors for overall survival. CONCLUSIONS Thromboembolic events are common in patients with muscle invasive bladder cancer who undergo neoadjuvant chemotherapy before and after radical cystectomy. Our results suggest that a prospective trial of thromboembolic event prophylaxis during neoadjuvant chemotherapy is warranted.

Variations in pelvic lymph node dissection in invasive bladder cancer: A Dutch nationwide population-based study during centralization of care

OBJECTIVES To assess temporal trends in radical cystectomy (RC) and pelvic lymph node dissection (PLND) and the effect of centralization of care in the Netherlands between 2006 and 2012. PATIENTS AND METHODS This nationwide population-based study included 3524 patients from the Netherlands Cancer Registry who underwent RC as the primary treatment for cT1-4a, N0 or Nx, M0 urothelial carcinoma. Annual application rates of PLND, median LNC, and rates of node-positive disease (pN+) were compared by linear-by-linear association. Multivariable logistic regression was performed to identify patients׳ and hospital characteristics associated with PLND and LNC≥10, and to study associations between LNC and pN+disease. RESULTS In total, 3,191 (91%) patients had PLND during RC and the use increased from 84% in 2006 to 96% in 2012 (P<0.001). Owing to centralization of care in 2010 (at least 10RCs/y/hospital), significantly more patients were treated in high-volume hospitals (≥20RC per year) in 2011 and 2012. PLND use was highest in males, younger patients and in academic, teaching, and high-volume hospitals (≥20RC per year). In 2012, PLND application rates were comparable for academic, teaching, and nonteaching hospitals (P = 0.344). Median LNC increased from 7 in 2006 to 13 in 2012 (P<0.001), 55% had an LNC≥10 (63% in 2012). Furthermore, lymph node count (LNC)≥10 was associated with cT3-4a and, pN+disease, R0 and treatment in academic, teaching, or high-volume hospitals (≥20RC per year). Rate of pN+disease increased from 18% to 24% between 2006 and 2012 (P = 0.014). This trend was significantly associated with increased LNC on a continuous scale (odds ratio = 1.03). CONCLUSIONS After centralization of care, PLND during RC for cT1-4a, N0 or Nx, M0 urothelial carcinoma has become standard in all types of Dutch hospitals. The increase in LNC between 2006 and 2012 was associated with a higher incidence of pN+disease and suggests more adequate template extension and adherence to contemporary guidelines in recent years.

Lymph node count at radical cystectomy does not influence long-term survival if surgeons adhere to a standardized template

INTRODUCTION Multiple bladder cancer studies report that the number of removed lymph nodes (lymph node count [LNC]) at radical cystectomy (RC) is positively associated with survival. Although these reports suggest that LNC can be used as a proxy for surgical quality, all studies used variable or inconsistent pelvic lymph node dissection (PLND) templates. We therefore wished to establish whether LNC at RC influences survival if surgeons adhere to a standardized PLND template. MATERIALS AND METHODS We included 274 patients who underwent RC from January 2005 until December 2012. All RCs were performed in either one of 2 hospitals (hospital A or B) by the same 4 urologists (all from hospital A) and a standardized PLND template was applied. PLND specimens were processed by 2 independent pathology departments (hospital A and B). We used Cox regression analysis to investigate the prognostic value of LNC adjusted for patient characteristics. We also compared LNC between hospitals and surgeons and investigated the effect of both the variables on overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS). RESULTS Median LNC was 17 (interquartile range = 12). At a median follow-up of 64.3 months, there was no association between LNC and OS (P = 0.328), CSS (P = 0.645), or DFS (P = 0.450). Median LNC was higher in hospital B than in hospital A (20.0 vs. 16.0, P = 0.003). Median LNC varied significantly among surgeons (12-20, P<0.001). Neither the hospital of surgery nor the surgeon performing PLND influenced OS (P = 0.771 and P = 0.982, respectively), CSS (P = 0.310 and P = 0.691, respectively), or DFS (P = 0.256 and P = 0.296, respectively). CONCLUSION If surgeons adhere to a standardized template, LNC at RC does not affect long-term survival.

Neoadjuvant Dose Dense MVAC versus Gemcitabine and Cisplatin in Patients with cT3-4aN0M0 Bladder Cancer Treated with Radical Cystectomy

Purpose: Level I evidence supports the usefulness of neoadjuvant cisplatin based chemotherapy for muscle invasive bladder cancer. Since dose dense MVAC (methotrexate, vinblastine, doxorubicin and cisplatin) has mostly replaced traditional MVAC, we compared pathological response and survival rates in patients with locally advanced bladder cancer who received neoadjuvant chemotherapy with dose dense MVAC vs gemcitabine and cisplatin. Materials and Methods: We retrospectively reviewed the records of patients with urothelial cancer who received neoadjuvant chemotherapy and underwent cystectomy at a total of 20 contributing institutions from 2000 to 2015. Patients with cT3‐4aN0M0 disease were selected for this analysis. The rates of ypT0N0 and ypT1N0 or less were compared between the gemcitabine and cisplatin, and dose dense MVAC regimens. Two multivariable Cox proportional hazards regression models of overall mortality were generated using preoperative and postoperative data. Results: Of the patients who underwent neoadjuvant chemotherapy and radical cystectomy during the study period 319 met our inclusion criteria. A significantly lower rate of ypT0N0 was observed in the gemcitabine and cisplatin arm than in the dose dense MVAC arm (14.6% vs 28.0%, p = 0.005). The rate of ypT1N0 or less was 30.1% for gemcitabine and cisplatin compared to 41.0% for dose dense MVAC (p = 0.07). The mean Kaplan‐Meier estimates of overall survival in the gemcitabine and cisplatin, and dose dense MVAC groups were 4.2 and 7.0 years, respectively (p = 0.001). On multivariable cox regression analysis based on preoperative data patients who received gemcitabine and cisplatin were at higher risk for death than patients who received dose dense MVAC (HR 2.07, 95% CI 1.25–3.42, p = 0.003). Lymph node invasion (HR 1.97, 95% CI 1.15–3.36, p = 0.01) and hydronephrosis (HR 2.18, 95% CI 1.43–3.30, p <0.001) were also associated with higher risk of death. Conclusions: In our retrospective cohort of patients with locally advanced bladder cancer dose dense MVAC was associated with higher complete pathological response and improved survival rates compared to gemcitabine and cisplatin. A clinical trial is warranted to validate these hypothesis generating results to test the superiority of neoadjuvant dose dense MVAC in patients with locally advanced bladder cancer.

Elevated Derived Neutrophil-to-Lymphocyte Ratio Corresponds With Poor Outcome in Patients Undergoing Pre-Operative Chemotherapy in Muscle-Invasive Bladder Cancer

Background: Platinum-based pre-operative chemotherapy (POC) for muscle-invasive bladder cancer (MIBC) increases the complete pathological response rate at cystectomy and improves overall survival. However, 60% of MIBC patients still has muscle-invasive disease at cystectomy despite POC. Therefore, accurate prediction of response to POC is an important clinical need. We hypothesized that an elevated neutrophil-to-lymphocyte ratio (NLR) corresponds with adverse outcome in patients undergoing POC and radical cystectomy. Objective: To explore the correlation between the NLR and outcome in MIBC patients treated by POC and radical cystectomy. Methods: In 123 MIBC patients (urothelial carcinoma) who were treated by platinum-based POC and radical cystectomy, the derived NLR (dNLR) was retrospectively calculated by dividing the neutrophil count by the difference between leukocytes and neutrophil counts, prior to the start of chemotherapy. The correlation of the dNLR with pathological response at cystectomy and survival was analyzed by logistic regression analysis or the Kaplan-Meier method. Results: The complete pathological response (ypT0N0Mx) rate was 28.5%, 8.9% obtained a partial response (ypTa/T1/TisN0Mx), and 62.6% were non-responders (stage ≥ ypT2 and/or N+). An elevated dNLR (>2.21) correlated with non-response to POC (OR 2.70, 95% confidence interval: 1.15–6.38, p = 0.02) but this effect was nullified when corrected for clinically node-positive disease and clinical T stage. Patients with an elevated dNLR had shorter progression-free and overall survival albeit non-significant (p = 0.42, and p = 0.45, respectively). Conclusions: An elevated dNLR corresponded with poor outcome in terms of survival and non-response to POC in MIBC patients undergoing radical surgery. However, after correction for well-known prognostic factors, such as positive lymph node status at diagnostic imaging and clinical T stage, the correlation for the dNLR was nullified. Therefore, we conclude that the dNLR is insufficient to predict response to POC in this heterogeneous patient population.

Endo-Urological Techniques for Benign Uretero-Ileal Strictures Have Poor Efficacy and Affect Renal Function

Introduction: Uretero-ileal strictures (UES) following urinary diversion are therapeutically challenging. We compared the efficacy, safety and renal outcome following therapeutic endo-urological techniques (EUTs) and open surgical revision of the anastomosis (SRA) for UES. Material and Methods: We retrospectively analysed all EUTs and SRAs performed for UES in 2 hospitals between 1987 and 2015. Restenosis was defined as recurrent radiographically diagnosed hydronephrosis and re-intervention. Renal function (estimated glomerular filtration rate [eGFR]) decrease was correlated with the number of EUTs per patient. Results: Eighty-five UES were treated with 105 EUTs and 31 open revisions. Due to total obstruction, 28 (27%) EUTs were aborted. During a median follow-up of 33 months, restenosis occurred following 53 out of 77 (69%) completed EUTs and 4 out of 31 (13%) SRAs (p < 0.001 on univariable and multivariable analyses). No serious (Clavien ≥3b) EUT-related complications occurred vs. 5 (19%) related to SRA (p < 0.001). The number of finalised EUTs was independently associated with eGFR loss (β = 12.3 mL/min/1.73 m2 loss per EUT, p = 0.008), with a significant cutoff value of >1 EUTs. SRA did not affect renal function (β = 6.8 mL/min/1.73 m2 loss, p = 0.276). Conclusions: Although EUTs are less invasive, they have an inferior efficacy to SRA. Our results suggest that a maximum of one EUT may be attempted without significantly compromising renal function.

Metric substage according to micro and extensive lamina propria invasion improves prognostics in T1 bladder cancer

BACKGROUND Reliable prognosticators for T1 bladder cancer (T1BC) are urgently needed. OBJECTIVE To compare the prognostic value of 2 substage systems for T1BC in patients treated by transurethral resection (TUR) and adjuvant bacillus Calmette-Guérin therapy. DESIGN, SETTING, AND PARTICIPANTS The slides of 601 primary T1BCs from four institutes were reviewed by 2 uropathologists and substaged according to 2 classifications: metric substage according to T1 microinvasive (T1m-lamina propria invasion <0.5mm) and T1 extensive invasive (pT1e-invasion ≥ 0.5mm), and according to invasion of the muscularis mucosae (MM) (T1a-invasion above or into MM/T1b). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Multivariable analyses for progression-free (PFS) and cancer-specific survival (CSS) were performed including substage, size, multiplicity, carcinoma in situ, sex, age, WHO-grade 1973, and WHO-grade 2004 as variables. RESULTS Median follow-up was 5.9 years (interquartile range: 3.3-9.0). Progression to T2BC was observed in 148 (25%) patients and 94 (16%) died of BC. The MM was not present at the invasion front in 135 (22%) of tumors. Slides were substaged as follows: 213 T1m and 388 T1e and 281 T1a and 320 T1b. On multivariable analysis, T1m/e substage and WHO 1973 grade were the strongest prognosticators for PFS (hazard ratio [HR] = 3.8 and HR = 1.8) and CSS (HR = 2.7 and HR = 2.6), respectively. Other prognostic factors for CSS were age (HR = 1.03), and tumor size (HR = 1.8). Substage according to MM-invasion was not significant. Our study was limited by its retrospective design and that standard re-TUR was not performed if TUR was macroscopically complete and muscularis propria was present in resected specimens. CONCLUSIONS Metric substaging of T1BC was possible in all cases of 601 T1BC patients and it was a strong independent prognosticator of both PFS and CSS.

Concurrent radiotherapy and panitumumab after lymph node dissection and induction chemotherapy for invasive bladder cancer

Purpose: In this prospective study we evaluated the safety and efficacy of concurrent radiotherapy and panitumumab following neoadjuvant/induction chemotherapy and pelvic lymph node dissection as a bladder preserving therapy for invasive bladder cancer. Materials and Methods: Patients with cT1-4N0-2M0 bladder cancer were treated with pelvic lymph node dissection and 4 cycles of platinum based induction chemotherapy followed by a 6½-week schedule of weekly panitumumab (2.5 mg/kg) and concurrent radiotherapy to the bladder (33 × 2 Gy). As the primary objective we compared concurrent radiotherapy and panitumumab toxicity to a historical control toxicity rate of concurrent cisplatin/radiotherapy (less than 35% of patients with Grade 3-5 toxicity). A sample size of 31 patients was estimated. Secondary end points included complete remission at 3-month followup, the bladder preservation rate, EGFR (epidermal growth factor receptor) expression and RAS mutational status. Results: Of the 38 cases initially included in this study 34 were staged cN0. After pelvic lymph node dissection 7 cases (21%) were up staged to pN+. Of the 38 patients 31 started concurrent radiotherapy and panitumumab. During concurrent radiotherapy and panitumumab 5 patients (16%, 95% CI 0–31) experienced systemic or local grade 3-4 toxicity. Four patients did not complete treatment due to adverse events. Complete remission was achieved in 29 of 31 patients (94%, 95% CI 83–100). At a median followup of 34 months 4 patients had local recurrence, for which 3 (10%) underwent salvage cystectomy. Two tumors showed EGFR or RAS mutation while 84% showed positive EGFR expression. Conclusions: Concurrent radiotherapy and panitumumab following induction chemotherapy and pelvic lymph node dissection has a safety profile that is noninferior to the historical profile of concurrent cisplatin/radiotherapy. The high complete remission and bladder preservation rates are promising and warrant further study.