Low-dose versus standard-dose gemcitabine infusion and cisplatin for patients with advanced bladder cancer: a randomized phase II trial—an update

Uncovering the epidemiology of bladder cancer in the Arab world: A review of risk factors, molecular mechanisms, and clinical features

Objective

Bladder cancer (BC) is a significant public health concern in the Middle East and North Africa, but the epidemiology and clinicopathology of the disease and contributors to high mortality in this region remain poorly understood. The aim of this systematic review was to investigate the epidemiological features of BC in the Arab world and compare them to those in Western countries in order to improve the management of this disease.

Methods

An extensive electronic search of the PubMed/PMC and Cochrane Library databases was conducted to identify all articles published until May 2022, following the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. A total of 95 articles were included in the final analysis after title, abstract, and full-text screening, with additional data obtained from the GLOBOCAN and WHO 2020 databases.

Results

Most of the included articles were case-control studies examining the risk factors and molecular mechanisms of BC. These studies originated from 10 different countries, with Egypt being the most active contributor. While BC in the Arab world shares some common risk factors with Western countries, such as smoking and occupational exposure, it also exhibits unique features related to schistosomiasis. The high mortality rates in this region are alarming and can be attributed to various factors, including the prevalence of smoking, the impact of schistosomiasis, a combination of genetic and socioeconomic factors, treatment shortages, and limited access to care or inadequate assessment of the quality of care.

Conclusion

Despite the relatively low incidence of BC in Arab countries, the mortality rates are among the highest worldwide. BC tends to be more aggressive in the Arab world, making it essential to implement strategies to address this burden.

Adverse events of different chemotherapy regimens in the first-line treatment of patients with advanced or metastatic urothelial cancer: A systematic review and network meta-analysis of randomized controlled trials

INTRODUCTION

The present systematic review and network meta-analysis (NMA) of randomized controlled trials (RCTs) aimed to compare the mortality rates related to adverse events (AEs) and discontinuation of treatment due to toxicity as well as all AEs of currently used chemotherapy regimens for first-line therapy of advanced or metastatic urothelial carcinoma of the bladder (UCB).

MATERIAL AND METHODS

The MEDLINE and EMBASE databases were searched for articles published between January 2000 and June 2020 according to the Preferred Reporting Items for Systematic Review and Meta-analysis extension statement for NMA. Eligible studies included RCTs comparing different first-line chemotherapy regimens for treating advanced or metastatic UCB and AEs as outcome measures. A NMA was performed to assess the mortality rates related to AEs and discontinuation of treatment due to toxicity as well as all AEs.

RESULTS

Fourteen trials comprising 2,615 patients met our eligibility criteria and formal NMAs were conducted. Results revealed that gemcitabine plus carboplatin had the lowest likelihood of mortality related to AEs (P score: 0.8079), while larotaxel plus cisplatin and paclitaxel, cisplatin plus gemcitabine had both a lower toxicity rate leading to discontinuation (P score: 0.7295 and P score: 0.7242, respectively). Compared with gemcitabine plus cisplatin (GC), most chemotherapy regimens were associated with a lower likelihood of thrombocytopenia, anemia, and cardiovascular toxicity. In contrast, most chemotherapy regimens compared with GC were associated with a higher likelihood of neutropenia, central (fatigue, neuropathy) and gastrointestinal AEs, infections, as well as renal and pulmonary toxicities.

CONCLUSION

Results of the present study demonstrated that hematological toxicity was the most prevalent AE associated with gemcitabine-containing regimens, while central AEs and febrile neutropenia were more commonly in taxane-containing regimens. GC had the lowest rate of gastrointestinal AEs, infection disorders, and pulmonary toxicities. Cisplatin-containing regimens were associated with a higher rate of renal and cardiovascular toxicity. These differential AEs may help in the detection of the personalized therapy in addition of efficacy data.

Clinical evidence for the first-line treatment of advanced urothelial carcinoma: Current paradigms and emerging treatment options

BACKGROUND

Patients with advanced urothelial carcinoma (UC) have poor outcomes, with 5-year survival rates of <5% for those with metastatic, stage IV disease. We have reviewed current treatment paradigms and emerging treatment options for these patients.

METHODS

The websites of seven national or international organizations were searched for metastatic UC treatment guidelines. Systematic literature reviews were conducted to identify evidence from randomized controlled trials (RCTs) of chemotherapy for patients with previously untreated, unresectable, stage IV UC. Searches included congress databases and articles published between 1990 and 2018. In order to align with the latest treatment paradigms in first-line advanced UC, a focused literature search was conducted to identify evidence supporting immuno-oncology (IO) agents.

RESULTS

For advanced UC, guidelines universally recommend cisplatin-based chemotherapy as first-line treatment for eligible patients and carboplatin-based regimens for those unfit to receive cisplatin. Despite the evaluation of a number of different cytotoxic regimens over the years, including triplet combinations, survival outcomes have not improved markedly with chemotherapy. Median overall survival with standard of care chemotherapy is ~13 months. Based on the results of single-arm, phase II studies, recent treatment guidelines have included atezolizumab (anti-PD-L1) and pembrolizumab (anti-PD-1) as first-line options for cisplatin-ineligible patients whose tumors express high levels of PD-L1. However, emerging evidence from RCTs of IO agents, including both cisplatin-eligible and cisplatin-ineligible patients, suggest that survival times exceeding 20 months are possible.

CONCLUSIONS

After having reached a plateau with chemotherapy, the treatment landscape for advanced UC is evolving. Survival outcomes for patients with advanced UC are improving with treatment modalities involving IO agents.

Naturally-Occurring Invasive Urothelial Carcinoma in Dogs, a Unique Model to Drive Advances in Managing Muscle Invasive Bladder Cancer in Humans

There is a great need to improve the outlook for people facing urinary bladder cancer, especially for patients with invasive urothelial carcinoma (InvUC) which is lethal in 50% of cases. Improved outcomes for patients with InvUC could come from advances on several fronts including emerging immunotherapies, targeted therapies, and new drug combinations; selection of patients most likely to respond to a given treatment based on molecular subtypes, immune signatures, and other characteristics; and prevention, early detection, and early intervention. Progress on all of these fronts will require clinically relevant animal models for translational research. The animal model(s) should possess key features that drive success or failure of cancer drugs in humans including tumor heterogeneity, genetic-epigenetic crosstalk, immune cell responsiveness, invasive and metastatic behavior, and molecular subtypes (e.g., luminal, basal). Experimental animal models, while essential in bladder cancer research, do not possess these collective features to accurately predict outcomes in humans. These key features, however, are present in naturally-occurring InvUC in pet dogs. Canine InvUC closely mimics muscle-invasive bladder cancer in humans in cellular and molecular features, molecular subtypes, immune response patterns, biological behavior (sites and frequency of metastasis), and response to therapy. Thus, dogs can offer a highly relevant animal model to complement other models in research for new therapies for bladder cancer. Clinical treatment trials in pet dogs with InvUC are considered a win-win-win scenario; the individual dog benefits from effective treatment, the results are expected to help other dogs, and the findings are expected to translate to better treatment outcomes in humans. In addition, the high breed-associated risk for InvUC in dogs (e.g., 20-fold increased risk in Scottish Terriers) offers an unparalleled opportunity to test new strategies in primary prevention, early detection, and early intervention. This review will provide an overview of canine InvUC, summarize the similarities (and differences) between canine and human InvUC, and provide evidence for the expanding value of this canine model in bladder cancer research.

Prolonged low-dose infusion for gemcitabine: a systematic review

Background

The present standard dose of gemcitabine (Gem), a pyrimidine antimetabolite, is 1,000-1,250 mg/m², and the infusion time is 30 min. However, pharmacological studies have demonstrated that Gem with prolonged infusion could attain a better accumulation rate of Gem triphosphate (active metabolites of Gem), indicating that Gem with prolonged infusion is superior to 30-min infusion. Thus, this systematic review aims to provide some references for Gem administered as a prolonged infusion.

Methods

We searched electronic databases, including PubMed, EMBASE, Cochrane Library, and CNKI, for trials. Keywords were "Gem," "prolonged infusion," and "low-dose." In addition, we used the Cochrane Handbook V5.1.0 and methodological index for non-randomized studies to evaluate the quality of randomized controlled trials (RCTs) and non-RCTs, respectively. Furthermore, Cochrane Collaboration guidelines and the PRISMA statement were adopted.

Results

We systematically reviewed 19 studies (5 RCTs and 14 non-RCTs). All studies assessed the efficacy and safety of Gem administered as a prolonged low-dose infusion (P-LDI) and reported that Gem administered as P-LDI was effective and well tolerated.

Conclusion

Gem administered as P-LDI is effective, safe, and economical, especially suited for patients with poor performance status or without good economic condition.

Enhanced taxane uptake into bladder tissues following co-administration with either mitomycin C, doxorubicin or gemcitabine: association to exfoliation processes

OBJECTIVE

To investigate the effect of three anticancer drugs (mitomycin c (MMC), doxorubicin or gemcitabine) on bladder wall morphology and the uptake of paclitaxel or docetaxel following coadministration. The primary objective of this study was to measure the uptake of MMC, doxorubicin or gemcitabine with or without exposure of the tissue to amine terminated cationic nanoparticles (CNPs) and to investigate any possible exfoliation effects of the three drugs on intact bladder tissue. The secondary objective was to investigate the uptake of taxane drugs (docetaxel, DTX) and paclitaxel, (PTX) from surfactant micelle formulations in the presence of MMC, doxorubicin or gemcitabine.

MATERIALS AND METHODS

Sections of fresh pig bladder tissue were incubated in Franz diffusion cells with the urothelial side exposed to solutions of doxorubicin, MMC and gemcitabine containing radioactive drug for 90 min. Some tissue samples were simultaneously exposed to each of the three drugs in combination with the surfactant micelle formulations of PTX (Taxol) or DTX (Taxotere). Tissue sections were then cryostat sectioned for drug quantitation by liquid scintillation counting or fixed for scanning electron microscopy and haematoxylin and eosin staining.

RESULTS

All three drugs caused exfoliation of the urothelial layer of bladder tissues. Drug uptake studies showed that all three drugs effectively penetrated the lamina propria through to the muscular layer over a 2-h incubation and these levels were unaffected by pre-treatment with CNPs. The uptake levels of the taxane drugs PTX and DTX were significantly enhanced following simultaneous treatment of bladders with MMC, doxorubicin or gemcitabine.

CONCLUSION

The exfoliation effects of MMC, doxorubicin and gemcitabine allow for good tissue penetration of these drugs with no additional effect from CNP treatment of bladders. The observed exfoliation effect of these amine-containing drugs probably arises from a cationic interaction with the mucus and urothelium cell layer in a manner similar to that previously reported for CNPs. These studies suggest that the lack of long-term clinical efficacy of these drugs may not arise from poor intravesical drug penetration but may result from a rapid diffusion of the drugs into the deeper vascularised muscular region with rapid drug clearance. The enhanced uptake of PTX or DTX following co-administration with MMC, doxorubicin or gemcitabine probably arises from the removal of the urothelial barrier by exfoliation allowing for improved taxane partitioning into superficial layers. These effects may allow for dual drug intravesical strategies offering greatly improved taxane uptake and potential additive drug effects for improved efficacy.

Independent Clinical Research May Alleviate Disparities in Cancer Treatment

Disparities in cancer care are a reality of the modern world. Unfortunately, current clinical research is in the hands of for-profit pharmaceutical companies and of researchers from the developed world. Problems specific to cancer care in developing countries and among deprivileged populations are ignored. Independent clinical research can offer new valuable knowledge and identify affordable and cost-effective treatments. As such, research not depending on commercial sponsors should become one of the important avenues to alleviate the problem of cancer disparities.

Front-line Treatment with Gemcitabine, Paclitaxel, and Doxorubicin for Patients With Unresectable or Metastatic Urothelial Cancer and Poor Renal Function: Final Results from a Phase II Study

OBJECTIVE

To estimate the response rate of gemcitabine, paclitaxel, and doxorubicin in patients with advanced urothelial carcinoma, we conducted a phase II clinical trial. Patients with renal insufficiency cannot receive standard cisplatin-based chemotherapy for urothelial carcinoma, and carboplatin-based regimens have proved unsatisfactory. Secondary end points for this study included overall survival, safety of the regimen, and safety of same-day pegfilgrastim dosing.

METHODS

A two-stage design was chosen with target response rate of 40%. Key inclusion criteria were metastatic or unresectable urothelial carcinoma, no prior chemotherapy, glomerular filtration rate <60 mL/min, and no dialysis. Gemcitabine (900 mg/m(2)), paclitaxel (135 mg/m(2)), and doxorubicin (40 mg/m(2)) were administered on day 1 of each 14-day cycle. Pegfilgrastim was given with every cycle on either day 1 or optionally day 2.

RESULTS

Forty patients were enrolled and 39 were treated. Median age was 72 years (range 51-89). There were 7 complete and 15 partial responses, for a response rate of 56.4% (95% confidence interval, 39.6-72.2). Most cycles (82.8%) were given with same-day pegfilgrastim. Notable grade 3 and 4 nonhematologic toxicities were fatigue and mucositis (10.3% each). There were 4 episodes of neutropenic fever (4 of 198 cycles [2%]; 4 of 39 patients [10.3%]) and no treatment-related deaths. Median overall survival was 14.4 months.

CONCLUSION

The combination of gemcitabine, paclitaxel, and doxorubicin is effective first-line chemotherapy for patients with advanced urothelial carcinoma and renal insufficiency. Neutropenic prophylaxis was acceptable whether pegfilgrastim was given immediately or 24 hours after chemotherapy.