[15O]H2O PET/MRI for Assessment of Complete Response to Neoadjuvant or Induction Chemotherapy in Patients with Muscle-Invasive Bladder Cancer: A Pilot Study

Background: Accurate assessment of therapy response to chemotherapy could possibly offer a bladder-sparing approach in selected patients with localized muscle-invasive bladder cancer (MIBC). The aim of this study was to evaluate whether [15O]H2O PET/MRI can be used for assessment of complete local pathological response to preoperative chemotherapy in patients with MIBC. Methods: This prospective pilot study included 13 patients with MIBC treated with neoadjuvant or induction chemotherapy and subsequent radical cystectomy. Patients underwent a [15O]H2O PET/MRI scan before chemotherapy and another scan after chemotherapy before radical cystectomy. Volumes of interest were delineated on T2-weighted MRI and transferred to parametric images for dynamic analysis. Tumor blood flow (TBF) was estimated by [15O]H2O PET. Changes in TBF were compared with histopathology. The Wilcoxon matched-pairs signed-ranks test was used for comparing pre- and post-chemotherapy measurements. Results: Mean TBF decreased by 49%. Mean TBF in complete responders (ypT0N0/ypTis) was not significantly different from non-complete responders (≥ypT1) (p = 0.52). Conclusions: Despite a measurable decrease in TBF after chemotherapy treatment, we were not able to estimate a TBF threshold for identifying complete responders to chemotherapy for MIBC patients. Further studies are needed to elucidate the potential of [15O]H2O PET/MRI in assessing therapy response in MIBC.

Predictive Value of Computed Tomography Following Neoadjuvant Chemotherapy for Muscle Invasive Bladder Cancer

BACKGROUND

Neoadjuvant chemotherapy (NAC) prior to radical cystectomy (RC) remains standard treatment for select patients with muscle-invasive bladder cancer (MIBC). Although computed tomography (CT) is often obtained prior to RC, its ability to predict pathologic response is poorly characterized.

OBJECTIVE

The purpose of this study is to evaluate the predictive value of CT in assessing disease burden after NAC.

METHODS

Patients with MIBC having received NAC prior to RC were identified. Pre- and post-NAC CT scans were reviewed by an abdominal radiologist. The correlation between pathologic complete response (PCR) and radiologic complete response (RCR) was determined as the primary aim. As a secondary aim, the correlation between pathologic partial response (PPR) and radiologic partial response (RPR) was determined. Logistic regression analysis was utilized to determine the predictive value of CT in determining disease burden at RC.

RESULTS

A total of 141 patients were identified for analysis. PCR and PPR was achieved in 34% and 16% of patients, respectively. The positive predictive value of post-NAC CT was 53.5% for PCR and 28.8% for PPR. The negative predictive value of post-NAC CT was 73.5% for PCR and 46.2% for PPR. There was no significant association between RCR and PCR (OR 1.13, p = 0.67). Similarly, there was no meaningful association between RPR and PPR, lymph node involvement, or presence of extravesical disease.

CONCLUSIONS

CT findings correlate poorly with final pathology at RC and should not be used to evaluate local disease burden.

Systematic Review and Meta-Analysis of Cisplatin Based Neoadjuvant Chemotherapy in Muscle Invasive Bladder Cancer

BACKGROUND

Cisplatin-based neoadjuvant chemotherapy is the standard of care for muscle invasive bladder cancer (MIBC).

OBJECTIVE

To compare the efficacy and safety of the two most commonly used cisplatin-based regimens; gemcitabine, and cisplatin (GC) vs. accelerated (dose-dense: dd) or conventional methotrexate, vinblastine, adriamycin, and cisplatin (MVAC).

METHODS

We searched MEDLINE, Embase, Scopus and other sources. Outcomes of interest included overall survival, downstaging to pT≤1, pathologic complete response (pCR), recurrence, and toxicity. Meta-analysis was conducted using the random-effects model.

RESULTS

We identified 24 studies. Efficacy outcomes were comparable between MVAC and GC for MIBC. dd-MVAC was associated with favorable efficacy compared to GC in terms of downstaging (OR 1.45; 95%CI 1.15-1.82) and all-cause mortality at longest follow-up (OR 0.63; 95%CI 0.44-0.81). However, GC was associated with a better safety profile in terms of febrile neutropenia (OR 0.32; 95%CI 0.13-0.80), anemia (OR 0.32; 95%CI 0.18-0.54), nausea and vomiting (OR 0.27; 95%CI 0.12-0.65) compared to dd-MVAC. Compared to MVAC, patients receiving GC had an increased risk of developing grade 3-4 thrombocytopenia (OR 4.70; 95%CI 1.59-13.89) and a lower risk of nausea and vomiting (OR 0.05; 95%CI 0.01-0.31). Certainty in the estimates was very low for most outcomes.

CONCLUSIONS

Efficacy and safety outcomes were comparable between MVAC and GC for MIBC. Including non-peer-reviewed studies showed higher efficacy with dd-MVAC. A phase III randomized trial comparing the two regimens is needed to guide clinical practice.

Control computerized tomography in neoadjuvant chemotherapy for muscle invasive urinary bladder cancer, has no value for treatment decisions and low correlation with nodal status

BACKGROUND

Control computerized tomography (cCT) is routinely used in many cystectomy centres before the final treatment cycle in patients with muscle-invasive urinary bladder cancer (MIBC) undergoing neoadjuvant chemotherapy (NAC). This is for evaluating response or nonresponse to NAC treatment. In a real-world retrospective cohort, we intended to evaluate the frequency of changed individual treatment strategies following cCT and to investigate any discrepancies between cCT-results on nodal staging and final pN-stages.

METHODS

We performed a retrospective data-based, multicenter study of 242 MIBC-patients, staged cT2N0M0-cT4aN0M0, having undergone NAC and radical cystectomy (RC) between 2008 and 2019 at four Swedish cystectomy centres. Statistical analysis was performed using IBM SPSS statistics 26.

RESULTS

Overall, 139/242 patients were examined with cCT. Six patients were staged as progressive at cCT and 5/139 (3.6%) underwent a change of previously planned treatment strategy. 2/6 patients with suspected progression (33%) did not change strategy and underwent all preplanned NAC-cycles plus RC. Only 1/6 patients assigned as progressive at the cCT, showed progression in the postoperative pathology specimen. In total 133/139 patients were considered being without progress on cCT, yet 28/133 (21%) presented with nodal progression at postoperative pathology examinations. Only 1/29 patients with histopathologically verified nodal dissemination were detected with cCT, thus 28/29 (96.6%) with pN + were undetected. The sensitivity for cCT to predict pTNM was 17% CI [0%-64%] and the specificity was 78% CI [71%-86%].

CONCLUSIONS

CCT prior to the final treatment cycle of NAC in MIBC, leads to a low percentage of treatment strategy changes and cCT cannot accurately predict pN-status.

[French ccAFU guidelines - update 2020-2022: bladder cancer]

OBJECTIVE

- To update French guidelines for the management of bladder cancer specifically non-muscle invasive (NMIBC) and muscle-invasive bladder cancers (MIBC).

METHODS

- A Medline search was achieved between 2018 and 2020, notably regarding diagnosis, options of treatment and follow-up of bladder cancer, to evaluate different references with levels of evidence.

RESULTS

- Diagnosis of NMIBC (Ta, T1, CIS) is based on a complete deep resection of the tumor. The use of fluorescence and a second-look indication are essential to improve initial diagnosis. Risks of both recurrence and progression can be estimated using the EORTC score. A stratification of patients into low, intermediate and high risk groups is pivotal for recommending adjuvant treatment: instillation of chemotherapy (immediate post-operative, standard schedule) or intravesical BCG (standard schedule and maintenance). Cystectomy is recommended in BCG-refractory patients. Extension evaluation of MIBC is based on contrast-enhanced pelvic-abdominal and thoracic CT-scan. Multiparametric MRI can be an alternative. Cystectomy associated with extended lymph nodes dissection is considered the gold standard for non-metastatic MIBC. It should be preceded by cisplatin-based neoadjuvant chemotherapy in eligible patients. An orthotopic bladder substitution should be proposed to both male and female patients with no contraindication and in cases of negative frozen urethral samples; otherwise transileal ureterostomy is recommended as urinary diversion. All patients should be included in an Early Recovery After Surgery (ERAS) protocol. For metastatic MIBC, first-line chemotherapy using platin is recommended (GC or MVAC), when performans status (PS <1) and renal function (creatinine clearance >60 mL/min) allow it (only in 50% of cases). In second line treatment, immunotherapy with pembrolizumab demonstrated a significant improvement in overall survival.

CONCLUSION

- These updated French guidelines will contribute to increase the level of urological care for the diagnosis and treatment of patients diagnosed with NMIBC and MIBC.

Effect of optimal neoadjuvant chemotherapy on oncological outcomes of locally advanced bladder cancer with laparoscopic radical cystectomy: A matched-pair analysis in a multicenter cohort

OBJECTIVES

To assess the effect of optimal neoadjuvant chemotherapy of at least three cycles of cisplatin-based regimen on oncological outcomes of clinical stage T3 or higher bladder cancer treated with laparoscopic radical cystectomy.

METHODS

Laparoscopic radical cystectomies carried out at 10 institutions were included in this retrospective study. The outcomes of patients who received optimal neoadjuvant chemotherapy and those who did not receive neoadjuvant chemotherapy were compared using propensity score matching in clinical stage T3-4 or T2 cohorts, separately.

RESULTS

Of the 455 patients screened, matched pairs of 54 patients in the clinical T3-4 cohort and 68 patients in the clinical T2 cohort were finally analyzed. In the cT3-4 cohort, the 5-year overall survival (78% vs 41%; P = 0.014), cancer-specific survival (81% vs 44%; P = 0.008) and recurrence-free survival (71% vs 53%; P = 0.049) were significantly higher in the optimal neoadjuvant chemotherapy group than in the no neoadjuvant chemotherapy group; no significant survival difference was shown between the two groups in the cT2 cohort. In the cT3-4 cohort, the incidence of local recurrence (4% vs 26%; P = 0.025) and abdominal or intrapelvic recurrence, including peritoneal carcinomatosis (7% vs 30%; P = 0.038), was significantly lower in the optimal neoadjuvant chemotherapy group.

CONCLUSIONS

Administration of optimal neoadjuvant chemotherapy has a significant survival benefit. It decreases the incidence of local and atypical recurrence patterns in patients with clinical stage T3 or higher locally advanced bladder cancer undergoing laparoscopic radical cystectomy.

Computerized tomography before the final treatment cycle of neoadjuvant chemotherapy or induction chemotherapy in muscle-invasive urinary bladder cancer, cannot predict pathoanatomical outcomes and does not reflect prognosis-results of a single centre retrospective prognostic study

Background

Evaluating the routine of using control computer tomography (cCT) for determining the response status of muscle-invasive bladder cancer (MIBC) prior to final cycle of neoadjuvant chemotherapy (NAC) or induction chemotherapy (IC), in terms of predicting histopathological pTNM-staging and pathoanatomical responses/non-responses. Secondly, predicting two and three-year overall survival (OS).

Methods

Seventy-seven patients with localized MIBC (cT2-4aN0M0) and 3 patients with minimal nodal dissemination (cN1-2), undergoing NAC or IC and radical cystectomy (RC), the years 2006–2014 at Norrland university hospital in Umeå, Sweden. Baseline pre-cystectomy CTs and cCTs prior to final chemotherapy-cycle, were reviewed and underwent attempted RECIST-criteria categorization, into five response/non-response related subgroups (n=71). The diagnostic accuracy of cCT in comparison with pTNM was assessed using sensitivity, specificity, positive- and negative likelihood ratios. OS for 2 and 3 years was calculated, both in relation to histopathological pTNM-stages in all patients (n=80) and for the patients with cCT-evaluated categories (n=71). Multivariable analysis for OS, was performed in correlation to pTNM-stages firstly, and to radiological staging secondly.

Results

The sensitivity of cCT to predict non-responders according to pTMN was 64% and specificity 36%. The positive likelihood ratio=1 and the negative likelihood ratio =1. CT-evaluations couldn’t accurately predict pTNM-stages in terms of response/non-response. No statistically significant results were found in correlating cCTs with two and three-year OS.

Conclusions

cCT prior to planned final preoperative chemotherapy-cycle in MIBC patients undergoing NAC or IC, has a poor correlation with pTNM and cannot predict pathoanatomical responses. Prediction of OS based on cCTs is unfeasible.

Multiparametric Magnetic Resonance Imaging as a Noninvasive Assessment of Tumor Response to Neoadjuvant Pembrolizumab in Muscle-invasive Bladder Cancer: Preliminary Findings from the PURE-01 Study

BACKGROUND

In the PURE-01 study, pembrolizumab was given preoperatively before radical cystectomy in clinical T2-4aN0M0 patients. An accurate clinical response assessment may be useful for developing new perioperative strategies in these patients.

OBJECTIVE

To evaluate the association between bladder multiparametric magnetic resonance imaging (mpMRI) findings after pembrolizumab and the pathological complete response (CR; pT0).

DESIGN, SETTING, AND PARTICIPANTS

Patients were staged using bladder mpMRI whereby radiologists were asked to characterize the following parameters: residual disease at T1- and T2-weighted images (step 1: yes/no), presence of hyperintense spots within the bladder wall on diffusion-weighted imaging (step 2: yes/no), and presence of pathological contrast enhancement (step 3: yes/no), before and after three cycles of pembrolizumab. Examinations were internally assessed by two senior radiologists and externally evaluated by a third senior radiologist.

INTERVENTION

To evaluate bladder tumor response after neoadjuvant pembrolizumab, mpMRI was used.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary objective was to predict the pT0 after neoadjuvant pembrolizumab by relying on the mpMRI findings. Cohen's kappa statistics was used to assess interobserver variability. Univariable analyses for pT0 were performed including internal and external post-therapy mpMRI steps.

RESULTS AND LIMITATIONS

From February 2017 to October 2018, 82 patients (164 total mpMRI assessments) were analyzed. The agreement between the internal and external mpMRI assessments after therapy was acceptable (κ values ranging from 0.5 to 0.76). Each mpMRI step was significantly associated with pT0 in both internal and external assessments. In patients with CR/no evidence of residual disease (NED) in all internally evaluated mpMRI steps (N = 37), the pT0 was seen in 23 (62%), compared with 19 of 26 externally evaluated NED patients (73%).

CONCLUSIONS

In post-pembrolizumab muscle-invasive bladder cancer, mpMRI sequence assessment had acceptable interobserver variability and represented the basis for the proposal of a radiological CR/NED status definition predicting the pT0 response to pembrolizumab. After validation of these findings with external datasets, we propose this tool for developing bladder-sparing immunotherapy maintenance therapies.

PATIENT SUMMARY

Assessment of the extent of disease in patients with muscle-invasive bladder cancer using conventional imaging yields serious limitations. In the PURE-01 study, we evaluated the potential of bladder multiparametric magnetic resonance imaging (MRI) to predict the pathological complete response to neoadjuvant pembrolizumab. After validation with larger datasets, the proposed stepwise assessment incorporating multiparametric MRI sequences will be used at our center to develop bladder-sparing approaches in future studies.

Imaging in Localized Bladder Cancer: Can Current Diagnostic Modalities Provide Accurate Local Tumor Staging?

PURPOSE OF REVIEW

Local tumor staging is paramount in the evaluation and management of bladder cancer. While neoadjuvant chemotherapy (NAC) followed by radical cystectomy and urinary diversion remains the gold standard for management of muscle-invasive bladder cancer, bladder-sparing regimens involving systemic chemotherapy and pelvic radiotherapy remain a viable option for select patients. Moreover, pre-cystectomy identification of patients with a complete response to NAC may obviate the need for radical cystectomy, but accurate post-therapy staging can be difficult to achieve. Contemporary imaging techniques may provide additional benefit in local tumor staging beyond standard imaging and cystoscopic biopsy. Our purpose is to summarize the ability of different imaging modalities to accurately stage bladder cancer patients in the treatment-naïve and post-chemotherapy settings.

RECENT FINDINGS

Contemporary investigations have been studying multiparametric magnetic resonance imaging (mp-MRI) in the evaluation of bladder cancer. Its recent incorporation into bladder cancer staging is mainly being assessed in treatment-naïve patients; however, different sequences are being studied to assess their accuracy after the introduction of chemotherapy and possibly radiation. Multiple recent studies incorporating cystoscopy and biopsy are proving to be less accurate than originally predicted. Imaging has generally had a very limited role in guiding therapy in localized bladder cancer, but with the incorporation of newer sequences and techniques, imaging is poised to become vital in decision-making strategies of this cancer. Reliable local tumor staging through improved imaging may help better select patients for bladder-sparing treatments while maintaining optimized oncologic outcomes and allow this paradigm to become more acceptable in the urologic oncology community.