Adjuvant intravesical therapy based on an in vitro cytotoxicity assay in the management of superficial transitional cell cancer of the urinary bladder

Intravesical Bacillus Calmette-Guérin versus mitomycin C for Ta and T1 bladder cancer

BACKGROUND

People with urothelial carcinoma of the bladder are at risk for recurrence and progression following transurethral resection of a bladder tumour (TURBT). Mitomycin C (MMC) and Bacillus Calmette-Guérin (BCG) are commonly used, competing forms of intravesical therapy for intermediate- or high-risk non-muscle invasive (Ta and T1) urothelial bladder cancer but their relative merits are somewhat uncertain.

OBJECTIVES

To assess the effects of BCG intravesical therapy compared to MMC intravesical therapy for treating intermediate- and high-risk Ta and T1 bladder cancer in adults.

SEARCH METHODS

We performed a systematic literature search in multiple databases (CENTRAL, MEDLINE, Embase, Web of Science, Scopus, LILACS), as well as in two clinical trial registries. We searched reference lists of relevant publications and abstract proceedings. We applied no language restrictions. The latest search was conducted in September 2019.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared intravesical BCG with intravesical MMC therapy for non-muscle invasive urothelial bladder cancer.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the literature, extracted data, assessed risk of bias and rated the quality of evidence according to GRADE per outcome. In the meta-analyses, we used the random-effects model.

MAIN RESULTS

We identified 12 RCTs comparing BCG versus MMC in participants with intermediate- and high-risk non-muscle invasive bladder tumours (published from 1995 to 2013). In total, 2932 participants were randomised. Time to death from any cause: BCG may make little or no difference on time to death from any cause compared to MMC (hazard ratio (HR) 0.97, 95% confidence interval (CI) 0.79 to 1.20; participants = 1132, studies = 5; 567 participants in the BCG arm and 565 in the MMC arm; low-certainty evidence). This corresponds to 6 fewer deaths (40 fewer to 36 more) per 1000 participants treated with BCG at five years. We downgraded the certainty of the evidence two levels due to study limitations and imprecision. Serious adverse effects: 12/577 participants treated with BCG experienced serious non-fatal adverse effects compared to 4/447 participants in the MMC group. The pooled risk ratio (RR) is 2.31 (95% CI 0.82 to 6.52; participants = 1024, studies = 5; low-certainty evidence). Therefore, BCG may increase the risk for serious adverse effects compared to MMC. This corresponds to nine more serious adverse effects (one fewer to 37 more) with BCG. We downgraded the certainty of the evidence two levels due to study limitations and imprecision. Time to recurrence: BCG may reduce the time to recurrence compared to MMC (HR 0.88, 95% CI 0.71 to 1.09; participants = 2616, studies = 11, 1273 participants in the BCG arm and 1343 in the MMC arm; low-certainty evidence). This corresponds to 41 fewer recurrences (104 fewer to 29 more) with BCG at five years. We downgraded the certainty of the evidence two levels due to study limitations, imprecision and inconsistency. Time to progression: BCG may make little or no difference on time to progression compared to MMC (HR 0.96, 95% CI 0.73 to 1.26; participants = 1622, studies = 6; 804 participants in the BCG arm and 818 in the MMC arm; low-certainty evidence). This corresponds to four fewer progressions (29 fewer to 27 more) with BCG at five years. We downgraded the certainty of the evidence two levels due to study limitations and imprecision. Quality of life: we found very limited data for this outcomes and were unable to estimate an effect size.

AUTHORS' CONCLUSIONS

Based on our findings, BCG may reduce the risk of recurrence over time although the Confidence Intervals include the possibility of no difference. It may have no effect on either the risk of progression or risk of death from any cause over time. BCG may cause more serious adverse events although the Confidence Intervals once again include the possibility of no difference. We were unable to determine the impact on quality of life. The certainty of the evidence was consistently low, due to concerns that include possible selection bias, performance bias, given the lack of blinding in these studies, and imprecision.

Synthesis and characterization of carboxylic acid conjugated, hydrophobically derivatized, hyperbranched polyglycerols as nanoparticulate drug carriers for cisplatin

Hyperbranched polyglycerols (HPGs) with hydrophobic cores and derivatized with methoxy poly(ethylene glycol) were synthesized and further functionalized with carboxylate groups to bind and deliver cisplatin. Low and high levels of carboxylate were conjugated to HPGs (HPG-C(8/10)-MePEG(6.5)-COOH(113) and HPG-C(8/10)-MePEG(6.5)-COOH(348)) and their structures were confirmed through NMR and FTIR spectroscopy and potentiometric titration. The hydrodynamic diameter of the HPGs ranged from 5-10 nm and the addition of COOH groups decreased the zeta potential of the polymers. HPG-C(8/10)-MePEG(6.5)-COOH(113) bound up to 10% w/w cisplatin, whereas HPG-C(8/10)-MePEG(6.5)-COOH(348) bound up to 20% w/w drug with 100% efficiency. Drug was released from HPG-C(8/10)-MePEG(6.5)-COOH(113) over 7 days at the same rate, regardless of the pH. Cisplatin release from HPG-C(8/10)-MePEG(6.5)-COOH(348) was significantly slower than HPG-C(8/10)-MePEG(6.5)-COOH(113) at pH 6 and 7.4, but similar at pH 4.5. Release of cisplatin into artificial urine was considerably faster than into buffer. Carboxylated HPGs demonstrated good biocompatibility, and drug-loaded HPGs effectively inhibited proliferation of KU-7-luc bladder cancer cells.

Serum Th1 and Th2 cytokine balance in patients of superficial transitional cell carcinoma of bladder pre- and post-intravesical combination immunotherapy

Combination therapy with intravesical bacillus Calmette-Guerin (BCG) plus interferon-alpha2b (IFN-alpha2b) for superficial transitional cell carcinoma (TCC) seems to be immune-dependent and activation of Th1 immune response is required for clinical efficacy. The present study evaluates circulating serum cytokine profiles (Th1/Th2 cytokines IFN-gamma, IL-2 TNF-alpha, IL-4, IL-6 and IL-10) in 41 bladder cancer patients prior to transurethral resection of tumor (TURBT) (pre-therapy), and following intravesical combination immunotherapy (post-therapy) and their association with recurrence. Mean levels of IL-2 and TNF-alpha were significantly reduced while IL-4, IL-6 and IL-10 were significantly enhanced in pre-therapy samples as compared to controls. Mean levels of IFN-gamma, IL-2 and TNF-alpha were significantly increased while IL-4 and IL-10 were significantly reduced in patients after instillation of combination immunotherapy. These findings suggest that bladder cancer patients develop Th2 dominant status with deficient type 1 immune response that shows tendency to reversal following therapy.

Permeation enhancer-containing water-in-oil nanoemulsions as carriers for intravesical cisplatin delivery

PURPOSE

In the present work, we developed water-in-oil (w/o) nanoemulsions for the intravesical administration of cisplatin.

METHODS

The nanoemulsions were made up of soybean oil as the oil phase and Span 80, Tween 80, or Brij 98 as the emulsifier system. alpha-Terpineol and oleic acid were incorporated as permeation enhancers. The physicochemical characteristics of droplet size, zeta potential, and viscosity were determined. Nanoemulsions were administered intravesically for 1 approximately 4 h to rats in vivo. Animals were subsequently sacrificed, and the bladders were harvested to examine drug accumulation and histology.

RESULTS

Ranges of the mean size and zeta potential were 30 approximately 90 nm and -3.4 to -9.3 mV, respectively. The addition of enhancers further reduced the size of the nanoemulsions. The viscosity of all systems exhibited Newtonian behavior. The cisplatin-loaded nanoemulsions were active against bladder cancer cells. The nanoemulsions with Brij 98 exhibited the complete inhibition of cell proliferation. The encapsulation of cisplatin and carboplatin, another derivative of cisplatin, in nanoemulsions resulted in slower and more-sustained release. The amount of drug which permeated into bladder tissues significantly increased when using carriers containing Brij 98, with the alpha-terpineol-containing formulation showing the best result. The nanoemulsion with alpha-terpineol prolonged the duration of higher drug accumulation to 3 approximately 4 h. At the later stage of administration (3 approximately 4 h), this system increased the bladder wall deposition of cisplatin and carboplatin by 2.4 approximately 3.3-fold compared to the control solution. Histological examination of the urothelium showed near-normal morphology in rats instilled with these nanoemulsions. alpha-Terpineol possibly caused slight desquamation of umbrella cells.

CONCLUSIONS

The nanoemulsions are feasible to load cisplatin for intravesical drug delivery.