Intravesical Chemotherapy and BCG for the Treatment of Bladder Cancer: Evidence and Opinion

Mathematical modeling of BCG-based bladder cancer treatment using socio-demographics

Cancer is one of the most widespread diseases around the world with millions of new patients each year. Bladder cancer is one of the most prevalent types of cancer affecting all individuals alike with no obvious "prototypical patient". The current standard treatment for BC follows a routine weekly Bacillus Calmette-Guérin (BCG) immunotherapy-based therapy protocol which is applied to all patients alike. The clinical outcomes associated with BCG treatment vary significantly among patients due to the biological and clinical complexity of the interaction between the immune system, treatments, and cancer cells. In this study, we take advantage of the patient's socio-demographics to offer a personalized mathematical model that describes the clinical dynamics associated with BCG-based treatment. To this end, we adopt a well-established BCG treatment model and integrate a machine learning component to temporally adjust and reconfigure key parameters within the model thus promoting its personalization. Using real clinical data, we show that our personalized model favorably compares with the original one in predicting the number of cancer cells at the end of the treatment, with [Formula: see text] improvement, on average.

Cell-Level Spatio-Temporal Model for a Bacillus Calmette–Guérin-Based Immunotherapy Treatment Protocol of Superficial Bladder Cancer

Bladder cancer is one of the most widespread types of cancer. Multiple treatments for non-invasive, superficial bladder cancer have been proposed over the last several decades with a weekly Bacillus Calmette–Guérin immunotherapy-based therapy protocol, which is considered the gold standard today. Nonetheless, due to the complexity of the interactions between the immune system, healthy cells, and cancer cells in the bladder’s microenvironment, clinical outcomes vary significantly among patients. Mathematical models are shown to be effective in predicting the treatment outcome based on the patient’s clinical condition at the beginning of the treatment. Even so, these models still have large errors for long-term treatments and patients that they do not fit. In this work, we utilize modern mathematical tools and propose a novel cell-level spatio-temporal mathematical model that takes into consideration the cell–cell and cell–environment interactions occurring in a realistic bladder’s geometric configuration in order to reduce these errors. We implement the model using the agent-based simulation approach, showing the impacts of different cancer tumor sizes and locations at the beginning of the treatment on the clinical outcomes for today’s gold-standard treatment protocol. In addition, we propose a genetic-algorithm-based approach to finding a successful and time-optimal treatment protocol for a given patient’s initial condition. Our results show that the current standard treatment protocol can be modified to produce cancer-free equilibrium for deeper cancer cells in the urothelium if the cancer cells’ spatial distribution is known, resulting in a greater success rate.

Current clinical trials in non-muscle invasive bladder cancer

BACKGROUND

The treatment options for non-muscle invasive bladder cancer (NMIBC) remain limited. Bacillus Calmette-Guerin (BCG) was the last major breakthrough in bladder cancer therapy almost 4 decades ago. There have been improvements in the understanding of immune therapies and cancer biology, leading to the development of novel agents. This has led to many clinical trials that are currently underway to find the next generation of therapies for NMIBC.

METHOD

We reviewed clinicaltrials.org and pubmed.gov to find the recently completed and ongoing clinical trials in NIMBC. Included in this review are clinical trials that are currently active and trials that were completed in and after 2014.

RESULT

Many trials with BCG-naive and BCG-unresponsive/recurrent/refractory/failure patients with NMIBC are either currently underway or have been recently completed. A wide variety of novel therapeutic agents are being investigated that range from cytotoxic agents to immunomodulatory agents to targeted molecular therapies. Other approaches include cancer vaccines, gene therapies, and chemoradiation potentiation agents. Novel drug-delivery methods are also being tested.

CONCLUSION

This comprehensive update of current trials provides researchers an overview of the current clinical trial landscape for patients with NMIBC.

Ruptured aortic aneurysm due to Mycobacterium bovis BCG with a delayed bacteriological diagnosis due to false negative result of the MPB 64 immunochromatographic assay

Background

Adjuvant therapy with bacillus Calmette–Guerin (BCG), a live attenuated strain of Mycobacterium bovis, has become the treatment of choice for low-risk superficial bladder carcinoma following transurethral resection of the bladder. Complications following vesical BCG instillations are uncommon but, in some cases, severe side-effects can occur such as sepsis or mycotic aneurysm. Besides usual laboratory techniques used for the diagnosis of Mycobacterium tuberculosis complex (MTBC) infections (smear microscopy and cultures), commercial immunochromatographic assays detecting MBP64, a 24 kDa M. tuberculosis complex-specific secretory protein, can rapidly distinguish MTBC and non-tuberculosis mycobacteria (NTM). MPB64 is found in M. tuberculosis, M. bovis and some but not all substrains of M.bovis BCG. Therefore, these immunochromatographic tests can lead to false negative results and delayed bacteriological diagnosis depending on the presence or absence of MPB64 protein in BCG substrains used for intravesical therapy.

Case presentation

We report the case of a 78-year-old male patient who was admitted to the hospital because of a 1-month history of unexplained fever, thrill, weight-loss and general malaise. His past medical history was marked by a non-muscle-invasive bladder carcinoma treated by transurethral resection followed by BCG instillations (Oncotice, Merck, USA). The patient was initially treated for a urinary tract infection but as fever persists after 72 h of antibiotherapy, urinary tract ultrasound was performed and revealed a large abdominal aortic aneurysm confirmed by computed tomography. Surgery was performed after multidisciplinary discussion. Direct smear of perioperative samples revealed acid-fast bacilli and both solid and liquid cultures were massively positive. Rapid identification of the positive mycobacterial culture was performed using an immunochromatographic assay based on the detection of the Mycobacterium tuberculosis MPB 64 antigen. The result was negative for Mycobacterium tuberculosis complex. After review of the medical record, a polymerase chain reaction (PCR) was performed and gave a positive result for M. tuberculosis complex. Anti-tuberculosis therapy was started immediately and the patient evolved favorably.

Conclusions

Through this case, we showed how the utilisation of MPB64 immunochromatographic assays can provide misleading information due to the variable presence of this protein among the different BCG strains. This case further illustrates the utility of rapid TB complex-specific PCR assays which provide a more reliable identification of all MTBC species.

Reducing recurrence in non-muscle-invasive bladder cancer using photodynamic diagnosis and immediate post-transurethral resection of the bladder chemoprophylaxis

OBJECTIVE

The aim of this study was to evaluate the effect of fluorescence cystoscopy and immediate post-transurethral resection of the bladder (TURB) chemoprophylaxis on the risk of recurrence of non-muscle-invasive bladder cancer (NMIBC) under routine clinical conditions.

MATERIALS AND METHODS

Fluorescence cystoscopy using hexyl-aminolevulinate and post-TURB chemoprophylaxis using mitomycin C were simultaneously introduced in an effort to reduce the recurrence of NMIBC. In total, 190 consecutive patients were enrolled over a 2 year period and followed as the intervention group; 216 patients treated over a 2 year period before introduction served as controls. An intention-to-treat analysis was performed with baseline control.

RESULTS

The recurrence risk was reduced by 41% (hazard ratio 0.59, 95% confidence interval 0.45-0.78) (intention-to-treat analysis). Median recurrence-free survival was extended from 13.6 months to 36.8 months. Every third follow-up TURB was avoided. Patients with low-risk tumors and patients with primary as well as recurrent disease benefited from the treatment.

CONCLUSIONS

Fluorescence cystoscopy and immediate post-TURB chemoprophylaxis effectively reduced the recurrence risk and numbers of follow-up procedures under clinical routine conditions.

Destruction of the bladder by single dose Mitomycin C for low-stage transitional cell carcinoma (TCC)--avoidance, recognition, management and consent

OBJECTIVES

To identify a cohort of patients under our care who have had significant and in some cases irreparable damage to their bladders after Mitomycin C (MMC) instillation. To highlight the importance of avoidance and recognition of bladder perforations during transurethral resection of bladder tumour (TURBT) and explore the issue of consent regarding MMC given the serious complications that may occur after its instillation.

PATIENTS AND METHODS

Patients referred to our tertiary centre for a second opinion to manage their complications after a suspected MMC leak was identified from the departmental database between January 2000 and December 2010. After collection of all the records, we established a cohort of six patients. All patients had their initial tumour resection elsewhere and were referred for specialist management thereafter. Details of the operating surgeon and cystoscopic findings were known only in half of the cases. Retrospective analysis of their notes including documentation from the referring centre was undertaken. This included a review of all the histology and imaging.

RESULTS

All patients had immediate severe pelvic pain on instillation of the MMC. Four of the six continue to have chronic pelvic pain. Two patients had urinary retention and three had severe lower urinary tract symptoms. One patient developed a frozen pelvis. Initial treatment was with an indwelling catheter for a period of 2-52 weeks to aid healing. Two patients had reconstructive surgery, one with success and the other with failure, as an intestinal patch failed to close the fistula and he continues with a catheter. One patient had an ileal conduit. No patient was warned of such complications.

CONCLUSIONS

Although rare, prophylactic MMC can have devastating consequences. Patients should be aware of such major risks. Strong emphasis should be placed on the quality of the initial TURBT coupled with the judgement of an experienced surgeon before to MMC instillation. The real clinical benefit could be reviewed and intravesical MMC offered only to patients who have a good chance of benefit.

Short-term administration of prulifloxacin in patients with nonmuscle-invasive bladder cancer: an effective option for the prevention of bacillus Calmette-Guérin-induced toxicity?

OBJECTIVE

To determine whether the new fluoroquinolone prulifloxacin might improve tolerance to Bacillus Calmette-Guérin (BCG) intravesical therapy in patients with bladder cancer.

PATIENTS AND METHODS

A series of 72 patients with intermediate- or high-risk nonmuscle-invasive bladder cancer were enrolled in this prospective, randomized, open-label, controlled clinical trial performed at a single tertiary care institution. After complete transurethral resection, patients were randomized to receive induction treatment with BCG and three capsules of prulifloxacin 600 mg or no prophylactic treatment (control group). Adverse events (AEs) were self-recorded by the patients after each instillation and classified by the investigator according to a classification grid considering account duration and intensity. Cystoscopy findings at 3 and 6 months were also recorded.

RESULTS

There was no significant difference in baseline symptoms between the groups. Overall, there was a significant decrease in the percentage of patients with at least one AE between instillations in prulifloxacin-treated group. The proportion of patients with moderate to severe AEs after the fourth instillation was significantly less in the prulifloxacin-treated group. There was a significant effect of prulifloxacin on the need for anti-tuberculosis treatment. More patients in the control group stopped or delayed the full induction course of BCG instillations (34% vs 19%, P=0.04). Recurrence rates were not affected by prulifloxacin treatment.

CONCLUSION

Prulifloxacin reduces the incidence of moderate to severe AEs from BCG intravesical therapy in patients with nonmuscle-invasive bladder cancer, improving compliance to the induction BCG course. These preliminary findings warrant further clinical research.

[Severe cystitis and perivesical collection posterior to Mitomycin C immediate instillation in a patient with inadverted bladder perforation]

We present the clinical case of a 40 years male patient who, after a TURBt for non-muscle invasive recurrence with inadverted vesical perforation and Mitomycin C immediate instillation, come in his fourth postoperative day to the emergency room with severe irritative urinary symptomatology. An ultrasound was indicated, documenting a perivesical collection. The management was conservative with vesical drilling for 10 days and a puncture/drainage was necessary to solve it.