Efficacy and Safety of Bladder Preservation Therapy in Combination with Atezolizumab and Radiation Therapy (BPT-ART) for Invasive Bladder Cancer: Interim Analysis from a Multicenter, Open-label, Prospective Phase 2 Trial

PURPOSE

To evaluate the safety and pathologic complete response (pCR) rate of radiation therapy with atezolizumab as bladder-preserving therapy for invasive bladder cancer.

METHODS AND MATERIALS

A multicenter, phase 2 study was conducted with patients with clinically T2-3 or very-high-risk T1 bladder cancer who were poor candidates for or refused radical cystectomy. The interim analysis of pCR is reported as a key secondary endpoint ahead of the progression-free survival rate primary endpoint. Radiation therapy (41.4 Gy to the small pelvic field and 16.2 Gy to the whole bladder) was given in addition to 1200 mg intravenous atezolizumab every 3 weeks. After 24 treatment weeks, response was assessed after transurethral resection, and tumor programmed cell death ligand-1 (PD-L1) expression was assessed using tumor-infiltrating immune cell scores.

RESULTS

Forty-five patients enrolled from January 2019 to May 2021 were analyzed. The most common clinical T stage was T2 (73.3%), followed by T1 (15.6%) and T3 (11.1%). Most tumors were solitary (77.8%), small (<3 cm) (57.8%), and without concurrent carcinoma in situ (88.9%). Thirty-eight patients (84.4%) achieved pCR. High pCR rates were achieved in older patients (90.9%) and in patients with high PD-L1-expressing tumors (95.8% vs 71.4%). Adverse events (AEs) occurred in 93.3% of patients, with diarrhea being the most common (55.6%), followed by frequent urination (42.2%) and dysuria (20.0%). The frequency of grade 3 AEs was 13.3%, whereas no grade 4 AEs were observed.

CONCLUSIONS

Combination therapy with radiation therapy and atezolizumab provided high pCR rates and acceptable toxicity, indicating it could be a promising option for bladder preservation therapy.

Optimisation of Radiation Therapy in Bladder Preservation Therapy for Patients With Clinical Stage T2N0M0 Bladder Cancer

AIMS

A novel bladder preservation therapy, the OMC (Osaka Medical College) regimen, which combines radiation therapy with balloon-occluded arterial infusion of anticancer agents, is a treatment option for patients with muscle-invasive bladder cancer (MIBC). We retrospectively analysed the effects of changes in radiation dose and irradiation field on treatment efficacy and adverse events.The purpose of this study is to use the results of this study to help determine a course of radiation therapy for bladder preservation therapy of cT2N0M0 MIBC.

MATERIALS AND METHODS

We examined 352 patients with clinical stage T2N0M0 (cT2N0M0) MIBC classified into the following groups based on the irradiation method: group A, the whole pelvis (50 Gy/25 fractions) + local bladder (10 Gy/5 fractions); group B, the small pelvis (50 Gy/25 fractions) + local bladder (10 Gy/5 fractions); group C, the whole pelvis (40 Gy/20 fractions) + local bladder (10 Gy/5 fractions).

RESULTS

The complete response rate, 3-year overall survival and progression-free survival rates in group A were 92.9%, 94.9% and 82.1%, respectively; in group B were 87.2%, 86.7% and 76.7%, respectively; and in group C were 95.2%, 92.6% and 71.1%, respectively. No significant differences between the groups were noted. The incidence of ≥grade 3 urinary tract and gastrointestinal toxicities were not significantly different among the groups (group A: 7.8%, 1.7%; B, 11.1%, 0%; C, 7.1%, 1.8%, respectively). The 3-year progression-free rates of the common iliac lymph node (CILN) region in patients who received whole-pelvis and small-pelvis irradiation were 99.0 and 89.0% (P < 0.01), respectively, with the latter group having significantly high lymph node recurrence in the CILN region.

CONCLUSIONS

Our findings showed that the optimal radiation therapy for patients with cT2N0M0 MIBC undergoing the OMC regimen is whole-pelvis irradiation including the CILN region, with a total dose of 50 Gy/25 fractions.

Bladder preservation therapy for muscle invasive bladder cancer: the past, present and future

Radical cystectomy is the gold standard treatment for muscle invasive bladder cancer, but some patients have medically inoperable disease or refuse cystectomy to preserve their bladder function. Bladder preservation therapy with transurethral resection of the bladder tumor and concurrent chemoradiotherapy, known as trimodal treatment, is regarded to be a curative-intent alternative to radical cystectomy for patients with muscle invasive bladder cancer during the past decade. After the development of immune checkpoint inhibitors, a world-changing breakthrough occurred in the field of metastatic urothelial carcinoma and many clinical trials have been conducted against non-muscle invasive bladder cancer. Interestingly, preclinical and clinical studies against other malignancies have shown that immune checkpoint inhibitors interact with the radiation-induced immune reaction. As half of the patients with muscle invasive bladder cancer are elderly, and some have renal dysfunction, not only as comorbidity but also because of hydronephrosis caused by their tumors, immune checkpoint inhibitors are expected to become part of a new therapeutic approach for combination treatment with radiotherapy. Accordingly, clinical trials testing immune checkpoint inhibitors have been initiated to preserve bladder for muscle invasive bladder cancer patients using radiation and immune checkpoint inhibitors with/without chemotherapy. The objective of this review is to summarize the evidence of trimodal therapy for muscle invasive bladder cancer during the past decade and to discuss the future directions of bladder preservation therapy in immuno-oncology era.

Asia Consensus Statement on NCCN Clinical Practice Guideline for bladder cancer

The Asia Consensus Statement (ACS) on the NCCN Guideline (NCCN-ACS) for treatment of bladder cancer version 1.2016 is designed to provide documentation of modifications of the 'parent' NCCN Guideline: Bladder Cancer (Version 2.2015). When considering ethnic differences or differences in health regulatory environments between Western and Asian countries, a process of adaptation to match the circumstances is helpful for utilizing the guidelines. The NCCN-ACS for bladder cancer consist of 11 ACSs, focused on diagnosis, imaging, surgical treatment, adjuvant intravesical chemotherapy or immunotherapy, periopererative (neodjuvant or adjuvant) chemotherapy and radiation oncology including bladder preservation. This mini-review will briefly summarize the bladder cancer version 1.2016 of the NCCN-ACS.

A systematic review and meta-analysis on the oncological long-term outcomes after trimodality therapy and radical cystectomy with or without neoadjuvant chemotherapy for muscle-invasive bladder cancer

OBJECTIVE

This study aimed to comprehensively analyze the oncological long-term outcomes of trimodal therapy (TMT) and radical cystectomy (RC) for the treatment of muscle-invasive bladder cancer (BC) with or without neoadjuvant chemotherapy (NAC).

PATIENTS AND METHODS

A systematic search was conducted according to the PRISMA guidelines for studies reporting on outcomes after TMT and RC. A total of 57 studies including 30,293 patients were included. The 10-year overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) rates for TMT and RC were assessed.

RESULTS

The mean 10-year OS was 30.9% for TMT and 35.1% for RC (P = 0.32). The mean 10-year DSS was 50.9% for TMT and 57.8% for RC (P = 0.26). NAC was administered before therapy to 453 (13.3%) of 3,402 patients treated with TMT and 812 (3.0%) of 27,867 patients treated with RC (P<0.001). Complete response (CR) was achieved in 1,545 (75.3%) of 2,051 evaluable patients treated with TMT. A 5-year OS, DSS, and RFS after CR were 66.9%, 78.3%, and 52.5%, respectively. Downstaging after transurethral bladder tumor resection or NAC to stage ≤pT1 at RC was reported in 2,416 (29.1%) of 8,311 patients. NAC significantly increased the rate of pT0 from 20.2% to 34.3% (P = 0.007) in cT2 and from 3.8% to 23.9% (P<0.001) in cT3-4. A 5-year OS, DSS, and RFS in downstaged patients (≤pT1) at RC were 75.7%, 88.3%, and 75.8%, respectively.

CONCLUSION

In this analysis, the survival outcomes of patients after TMT and RC for MIBC were comparable. Patients who experienced downstaging after NAC and RC exhibited improved survival compared to patients treated with RC only. Best survival outcomes after TMT are associated with CR to this approach.

Essential content of evidence-based clinical practice guidelines for bladder cancer: The Japanese Urological Association 2015 update

The Japanese Urological Association revised the clinical practice guidelines for bladder cancer in April 2015. This was the first update carried out in the 6 years since the development of the initial clinical practice guidelines for bladder cancer in 2009. The descriptive content was revised, and additions were made with a focus on new-found evidence and advances in the latest medical practices, and on the basis of the increasingly aging population observed in the underlying social context in Japan. An algorithm for the treatment of bladder cancer has been presented as a new trial. In the present article, we will introduce the essential contents and clinical questions that address the present revisions.

Radical cystectomy versus organ-sparing trimodality treatment in muscle-invasive bladder cancer: A systematic review of clinical trials

BACKGROUND

Radical cystectomy (RC) represents the mainstay of treatment in patients with muscle-invasive urinary bladder cancer but how it compares with the best organ preservation approach is not known.

MATERIALS AND METHODS

The objective of our review is to compare the 5-year overall survival (OS) rates from retrospective and prospective studies of RC and trimodality treatment (TMT), i.e. concurrent delivery of chemotherapy and radiotherapy after a transurethral resection of bladder tumor (TURBT), involving a total of 10,265 and 3131 patients, respectively. We used random-effect models to pool outcomes across studies and compared event rates of combined outcomes for TMT and RC using an interaction test.

RESULTS

The median 5-year OS rate was 57% in the TMT group, when compared with 52% (P=0.04), 51% (P=0.02) and 53% (P=0.38) in the whole group receiving RC or the group treated with RC alone or RC+chemotherapy, respectively. The hazard risk (HR) of mortality of patients treated with TMT or RC was 1.22 (95% CI=1.13-1.32) with an absolute benefit of 5% in favor of the former. The HR of mortality from TMT persisted significantly better not only versus the group treated with RC alone (HR=1.22; 95% CI=1.12-1.32), but also versus the group receiving RC+chemotherapy (HR=1.22; 95% CI=1.09-1.36). Multivariate analysis confirmed TMT as a significant prognostic variable for both RC alone and RC+chemotherapy.

CONCLUSION

Compared with RC, TMT seems to be associated with a better outcome for patients with muscle-invasive bladder cancer (MIBC). The addition of chemotherapy may improve the RC outcome in some subgroups of patients with a higher probability of micrometastases. Prospective randomized trials are urged to verify these findings and better define the role of organ preservation and radical treatment strategy in the management of patients with MIBC.

Intra-Arterial Chemotherapy for Muscle-Invasive Bladder Cancer Following Transurethral Resection

Purpose: To assess the efficacy of intra-arterial chemotherapy as a bladder-preservation treatment in patients with muscle-invasive bladder cancer (MIBC) following transurethral resection of bladder tumors (TURBT). Materials and Methods: From 2005 June to 2012 November, 46 patients diagnosed with MIBC (clinical stage T2-T3N0M0) underwent three courses of cisplatin-based intra-arterial chemotherapy as a remedial approach for bladder preservation after TURBT. All patients also received intravesical instillation of chemotherapy as a maintenance strategy. Results: All 46 patients completed the treatment with minor complications. The median follow-up time was 34.5 months (range, 8-87 months). Thirty-two patients (69.6%) demonstrated complete response. The three-year and five-year overall survival was 70.65 and 61.23%, and the disease-specific survival over the same periods was 78.03 and 67.62%, respectively. During the entire follow-up period, more than 80% preserved their bladder. Conclusions: Intra-arterial chemotherapy can be performed as a remedial treatment for MIBC patient following TURBT. Combined with TURBT, it offers an option for bladder preservation therapy on patients who are unable or unwilling to undergo radical cystectomy.

A systematic review and meta-analysis of clinical trials of bladder-sparing trimodality treatment for muscle-invasive bladder cancer (MIBC)

PURPOSE

Despite the numerous prospective and retrospective studies published during the last 2 decades aiming at testing the safety and the efficacy of trimodality therapy (TMT) as a conservative treatment, an optimal therapeutic strategy has not yet been identified. We made a systematic overview of the 5-year outcomes from 31 trials of combined chemotherapy and radiation (CRT) after transurethral resection of muscle-infiltrating bladder tumours (TURBT), the so-called trimodality therapy. We took into consideration the results of each trial i.e. the rate of complete response (CR), local muscle-invasive local failure (LF), salvage cystectomy (SC), 5-year overall survival (OS) and 5-year bladder intact survival (BIS) from 3315 patients.

RESULTS

About half of the patients were treated with a preliminary induction followed by a consolidation CRT course in CR, or SC in non-CR patients (split treatment). The remaining half of the patients underwent an upfront full-dose CRT course (continuous treatment) with SC reserved to non-CR patients. Excellent results were obtained by trimodality therapy (TMT), with 78% CR, 28% muscle infiltrating LF and 21% SC in patients with MIBC. The 5-year OS and BIS rates were 56% and 42%, respectively. At univariate analysis, CR, and SC rates appeared to be significantly better in the continuous than in the split treatment group. Multivariate analysis confirmed the former regimen as a significant prognostic variables only for CR, while CP-based regimen was a significant prognostic factor for SC. The subgroup analysis revealed a significant improvement in 5-year OS rate of continuous over split treatment in later stage tumours. No relevant benefit was observed with the addition of other drugs to cisplatin (CP) or neo-adjuvant chemotherapy (NATC) to CRT, although, in patients receiving NACT, significantly better CR and OS rates were seen in the continuous than split treatment.

CONCLUSIONS

The results of this overview seem to indicate that TMT is able to produce excellent 5-year OS rates, no matter how it is done (continuous or split). No significant difference in 5-year OS rates could be observed between the two treatment regimens, although the continuous may offer some advantage compared to split treatment in terms of higher CR and, likely lower SC rates. The highest benefit might be achieved in later stage tumours, using a total radiation equivalent dose when delivered in 2Gy/fraction (EQD2) of more than 60Gy in combination with CP based regimes and preceded by 2-3 NACT cycles. Appropriate randomized trials should be addressed to confirm the results of the present review.

Effect of internal iliac artery chemotherapy after transurethral resection of bladder tumor for muscle invasive bladder cancer

OBJECTIVE

To evaluate the clinical effect of transurethral resection of bladder tumor (TUR-BT) combined with internal iliac artery chemotherapy and intravesical instillation therapy for muscle invasive bladder cancer (MIBC).

METHODS

From February 2007 to April 2014, 62 patients with MIBC were treated with TUR-BT combined with intravesical instillation therapy, with or without internal iliac artery chemotherapy, and the chemotherapy regimen is gemcitabine and cisplatin (GC). The bladder preservation and survival rate as well as cancer-specific survival (CSS) rate and overall survival (OS) rate of the two groups were compared.

RESULTS

Sixty-two patients were followed-up for 26-102 months with an average of 58.4±3.1 months. Recurrence-free survival (RFS) at 2-year for TUR + GC group and TUR group were 77.8% and 53.8%, respectively. Bladder preserved rate (BPR) at 3-year for TUR + GC group and TUR group were 94.4% and 80.8%. CSS rate at 2-year for TUR + GC group and TUR group were 94.4% and 84.6%. The disease-free survival (DFS) at 1-year for TUR + GC group and TUR group were 83.3% and 61.5%, and 77.8% and 53.8% for the 2(nd) year. OS at 2-year for TUR + GC group and TUR group were 88.9% and 92.3%.

CONCLUSIONS

TUR-BT and intravesical instillation therapy combined with internal iliac artery chemotherapy for MIBC had a better outcome at RFS, BPR and DFS than the treatment without internal iliac artery chemotherapy, and no difference in OS and CSS.

Analysis of Intravesical Recurrence After Bladder-preserving Therapy for Muscle-invasive Bladder Cancer

OBJECTIVE

The aim of the present study was to analyze the pattern of recurrences after bladder-preserving therapy for muscle-invasive bladder cancer.

METHODS

The subjects were 77 patients with T2-3N0M0 bladder cancer whose bladder was preserved by intra-arterial chemotherapy and radiation. The patterns of the first recurrences were retrospectively analyzed.

RESULTS

With a median follow-up of 38.5 months, 17 patients (22.1%) experienced intravesical recurrence without metastasis, 14 (82.4%) of which were cases of non-muscle-invasive bladder cancer recurrence and 3 (17.6%) of which were muscle-invasive bladder cancer recurrences. Muscle-invasive bladder cancer recurred at the same site as the initial tumor site in all three cases, whereas non-muscle-invasive bladder cancer recurred at different sites in 64% of the patients in that group. The peak hazard of the non-muscle-invasive bladder cancer recurrence was observed at around a year after treatment. Recurrent non-muscle-invasive bladder cancer was of a significantly lower histological grade with lower Ki-67-labeling indices than the initial muscle-invasive bladder cancer. Twelve (85.7%) of 14 patients with non-muscle-invasive bladder cancer recurrence achieved disease-free status. The multivariate analysis revealed that multiplicity, grade and tumor size were significantly correlated with the recurrence (P= 0.0001, 0.0442 and 0.0412, respectively).

CONCLUSIONS

Most of the recurrences after bladder-preserving therapy were cases of non-muscle-invasive bladder cancer. The recurrence pattern and characteristics of the tumors did not differ from those of primary non-muscle-invasive bladder cancer. Patients with high-risk factors would be candidates for prophylactic intravesical therapy for non-muscle-invasive bladder cancer recurrence.

Neoadjuvant and adjuvant chemotherapy for locally advanced bladder carcinoma: development of novel bladder preservation approach, Osaka Medical College regimen

Cisplatin-based chemotherapy has been widely used in a neoadjuvant as well as adjuvant setting. Furthermore, trimodal approaches including complete transurethral resection of the bladder tumor followed by combined chemotherapy and radiation have generally been performed as bladder preservation therapy. However, none of the protocols have achieved a 5-year survival rate of more than 70%. Additionally, the toxicity of chemotherapy and/or a decreased quality of life due to urinary diversion cannot be ignored, as most patients with bladder cancer are elderly. We therefore newly developed the novel trimodal approach of "combined therapy using balloon-occluded arterial infusion of anticancer agent and hemodialysis with concurrent radiation, which delivers an extremely high concentration of anticancer agent to the site of a tumor without systemic adverse effects ("Osaka Medical College regimen" referred to as the OMC regimen). We initially applied the OMC regimen as neoadjuvant chemotherapy for locally advanced bladder cancer. However, since more than 85% of patients with histologically-proven urothelial cancer achieved complete response with no evidence of recurrence after a mean follow-up of 170 (range 21-814) weeks, we have been applying the OMC-regimen as a new approach for bladder sparing therapy. We summarize the advantage and/or disadvantage of chemotherapy in neoadjuvant as well as adjuvant settings, and show the details of our newly developed bladder sparing approach OMC regimen in this review.

Conservative treatment of invasive bladder cancer

The concept of organ-preserving therapies is a trend in modern oncology, and several tumour types are now treated in this fashion. Trimodality therapy consisting of as thorough a transurethral resection of the bladder tumour as is judged safe, followed by concomitant chemoradiation therapy, is emerging as an attractive alternative for bladder preservation in selected patients with muscle-invasive bladder cancer. Long-term data from multiple institutional and cooperative group studies have shown that this approach is safe and effective and that it provides patients with the opportunity to maintain an intact and functional bladder with a survival rate similar to that for modern radical cystectomy.

[Bladder preservation using chemoradiation therapy for locally invasive bladder cancer]

PURPOSE

We investigated the long-term results and molecular markers of outcome with selective organ preservation in invasive bladder cancer using chemoradiation therapy.

PATIENTS AND METHODS

We examined locally invasive bladder cancer in 32 patients (30 men, 2 women; mean age at treatment 68.1 years) who underwent bladder-sparing protocols in the Department of Urology at Sumitomo Hospital between 2000 and 2005. The clinical stage was T2, T3, and T4 in 13, 16, and 3 patients, respectively. Our protocol includes aggressive transurethral resection of the bladder tumor (TURBT) and 46 Gy radiotherapy (2 Gy/fraction, 5 fractions/week) to the pelvis with concurrent cisplatin chemotherapy (20 mg/body/day, 5 days/week, the first and fourth week, intravenously). The initial evaluation included magnetic resonance imaging (MRI), urine cytology, and cystoscopy with a biopsy. During follow-up, if the patients developed superficial recurrence, they was treated with TURBT and intravesical Bacillus Calmette-Guérin (BCG), while patients with invasive recurrence were advised to undergo a salvage cystectomy. We examined the association between the expression of the Bcl-2 family in pretreatment TUR specimens and patient outcome. The mean follow-up was 54.6 months.

RESULTS

The first assessment after the induction chemoradiotherapy showed that bladder preservation was achieved in 27 patients (84.4%). The actuarial local control rate with an intact bladder was 56.3% (18 patients) at 3 years. The 1-, 3-, and 5-year cancer-specific survival rate was 90.6, 84.0, and 66.9%, respectively. The 5-year cancer-specific survival rate was 75.0, 67.2, and 33.3% in T2, T3, and T4, respectively. Bcl-x positivity was significantly associated with a poor cancer-specific survival rate (log-rank test, p = 0.038).

CONCLUSIONS

Chemoradiation therapy for invasive bladder cancer can achieve survival rates similar to those in patients treated with radical cystectomy, with successful bladder preservation. Our results suggest that the expression of Bcl-x is a potential prognostic marker for chemoradiation therapy in invasive bladder cancer.

Evidence-based clinical practice guidelines for bladder cancer (summary - JUA 2009 Edition)

In Japan, until now, the treatment of bladder cancer has been based on guidelines from overseas. The problem with this practice is that the options recommended in overseas guidelines are not necessarily suitable for Japanese clinical practice. A relatively large number of clinical trials have been conducted in Japan in the field of bladder cancer, and the Japanese Urological Association (JUA) considered it appropriate to formulate their own guidelines. These Guidelines present an overview of bladder cancer at each clinical stage, followed by clinical questions that address problems frequently faced in everyday clinical practice. In this English translation of a shortened version of the original Guidelines, we have abridged each overview, summarized each clinical question and its answer, and only included the references we considered of particular importance.