Improving the efficacy of BCG immunotherapy by dose reduction

Trial watch: FDA-approved Toll-like receptor agonists for cancer therapy

Toll-like receptors (TLRs) have first been characterized for their capacity to detect conserved microbial components like lipopolysaccharide (LPS) and double-stranded RNA, resulting in the elicitation of potent (innate) immune responses against invading pathogens. More recently, TLRs have also been shown to promote the activation of the cognate immune system against cancer cells. Today, only three TLR agonists are approved by FDA for use in humans: the bacillus Calmette-Guérin (BCG), monophosphoryl lipid A (MPL) and imiquimod. BCG (an attenuated strain of Mycobacterium bovis) is mainly used as a vaccine against tuberculosis, but also for the immunotherapy of in situ bladder carcinoma. MPL (derived from the LPS of Salmonella minnesota) is included in the formulation of Cervarix®, a vaccine against human papillomavirus-16 and -18. Imiquimod (a synthetic imidazoquinoline) is routinely employed for actinic keratosis, superficial basal cell carcinoma, and external genital warts (condylomata acuminata). In this Trial Watch, we will summarize the results of recently completed clinical trials and discuss the progress of ongoing studies that have evaluated/are evaluating FDA-approved TLR agonists as off-label medications for cancer therapy.

[BCG strain shortage from 2012 to 2014: Evaluation of its impact on the management of patients with high-risk NMIBC]

INTRODUCTION

BCG instillations are the gold-standard treatment for high-risk non-muscle-invasive bladder cancer (NMIBC) with a decreased risk of tumor recurrence and muscle infiltration. From 2012 to 2014, a stock shortage of the Connaught strain has led to the cessation of supply for immucyst in France. The objective of this study was to evaluate the potential impact of BCG shortage on the management of patients with NMIBC.

PATIENTS AND METHODS

We conducted a retrospective single-center study including patients followed from May 2005 to May 2015 with a high-risk NMIBC (primo-diagnosis). Patients were separated into two groups: not impacted by the shortage (NISG: 56 patients) and impacted by the shortage (ISG: 53 patients). Data on tumour recurrence (RFS), muscle progression (PFS) and overall and specific survival (OS and SS) were also analysed.

RESULTS

The BCG induction schedule could not be carried out in 20.8% of cases in the ISG compared to only 5.3% of cases in NISG (P=0.02). Similarly, the maintenance treatment was incomplete for 56.6% of cases versus 37.5% in NISG (P=0.047). Nevertheless, it should be underlined that very high-risk NMIBC received a complete induction BCG schedule. The ISG seems to have benefited with the evolution of the guidelines with the use of diagnosis bladder fluorescence but without significant difference on the rate of second look bladder trans-uretral resection. The cystectomy rate was higher in ISG. No significant difference in RFS, PFS, OS, and SS between the two groups.

CONCLUSION

In our experience, RFS, PFS, OS or SS were not impacted by the BCG shortage. These data may be explained by a better selection of very high-risk patients including the recommended BCG schedule and more frequently the use of diagnosis bladder fluorescence.

LEVEL OF EVIDENCE

3.

Alternative Therapies to Bacillus Calmette-Guérin Shortage for Nonmuscle Invasive Bladder Cancer in Brazil and Other Underdeveloped Countries: Management Considerations

Bacillus Calmette-Guérin (BCG) plays a cornerstone role in the management of nonmuscle invasive urothelial carcinoma of the bladder. However, there has been a worldwide intermittent BCG shortage in recent years that may affect the care of patients with bladder cancer and pose difficult clinical decisions to urologists and clinical oncologists. This literature review aims to clarify alternatives to BCG during a shortage and propose measures to replace BCG, mainly in Brazil and probably in other low- and middle-income countries, where not all studied and commonly suggested treatments are available.

Prevention of topic toxicity of BCG with single-dose prulifloxacin. Preliminary results of a randomized pilot study

Introduction

Toxicity is a major problem for patients undergoing intravesical therapy with Bacillus Calmette-Guérin (BCG) for the conservative management of intermediate or high-risk non-muscle invasive bladder cancer (NMI-BC). A prospective pilot trial was designed to evaluate the adoption of a single dose of prulifloxacin to prevent the toxicity of BCG. Treatment tolerability and its possible influence on BCG efficacy have been analyzed.

Materials and Methods

The study was designed to evaluate the action of prulifloxacin in patients with intermediate or high-risk NMI-BC, undergoing 6–week induction cycle of BCG. Main exclusion criteria were previous intravesical therapy, urinary infection and any other factor that could influence tolerability to BCG intravesical immunotherapy. The patients were randomized to receive BCG alone versus BCG plus prulifloxacin. BCG toxicity and local tolerability were evaluated by self-administered EORTC QLQ-BLS24 questionnaire, and BCG adverse events (AEs) were classified according a four-class classification. The toxicity and tolerability evaluations were performed at baseline, one week after every instillation and one week and one month after the last instillation. Cystoscopy and cytology were performed 3–monthly. Recurrence and progression were recorded.

Results

The study included 43 patients receiving 258 instillations of BCG. The patients were randomized to receive BCG alone (Arm A: 132 instillations in 22 patients) versus BCG plus prulifloxacin given as a single oral dose (600 mg) 6 hours after the instillation. An advantage in favor of prulifloxacin prophylaxis emerged, according to EORTC QLQ-BLS24, in overall incidence of nocturnal micturitions (56% vs 28.6%; p=0.001), insomnia (40% vs 14.3%; p=0.002), urgency (70% vs 42.6%; p=0.05), incontinence (44% vs 12.7%; p=0.01) and bothersome events due to intravesical therapy (84% vs 63.5%; p=0.02). Systemic class IIB and III adverse events occurred in only 14.2% and 3.5% of the patients, respectively. No class IV AE was detected. Due to the low incidence no statistically significant difference was evident between the two arms (p=0.6). Three patients of Arm B and 1 patient of Arm A interrupted the treatment, after the 3rd - 4th instillation. Anti-tuberculosis therapy war required for 3 months in only one patient. Three and 2 instillations were postponed for one-(two) week(s) in Arm B and Arm A, respectively. Prulifloxacin, generally well tolerated, was withdrawn in one patient due to skin allergic reaction. Recurrence rate at a mean follow-up of 12 months did not significantly differ between the two arms.

Conclusions

Prulifloxacin decreases the incidence of local symptoms and improves the compliance to BCG intravesical therapy. Due to the low number of events, no evidence emerges in our study about its capability of preventing severe systemic toxicity, although it has proved effective in reducing local symptoms.

A comparative study between full-dose and half-dose intravesical immune bacille Calmette-Guérin injection in the management of superficial bladder cancer

OBJECTIVES

To determine whether a half-dose of bacille Calmette-Guérin (BCG) can reduce toxicity without affecting its efficacy in the management of non-muscle-invasive bladder cancer.

PATIENTS AND METHODS

From January 2012 to January 2014, 80 patients with superficial bladder cancer and in the intermediate-risk group were simply randomised to receive two different doses of BCG, i.e., a full dose of 90 mg (group A) or a half-dose of 45 mg (group B). There were no significant differences in clinical and pathological characteristics between the groups. At completion of the study, 40 patients could be evaluated in each group.

RESULTS

All patients were evaluated for a follow-up of 12 months after treatment. There was no significant difference in recurrence rate (15 patients, 38%, in group A and 16, 40%, in group B) in the two groups, and no difference in progression rate of the disease, at eight patients (20%) in each group. There were significant differences between groups A and B in toxicity (grade 1 adverse events, 70% vs. 60%; grade 2, 18% vs. 7.5%, respectively). Grade 3 adverse events were only reported in group A (2.5%).

CONCLUSION

The half dose of intravesical BCG instillation can reduce the toxicity and side-effects that are associated with the treatment of superficial bladder cancer, without affecting the efficacy of therapy.

Efficacy and tolerance of one-third full dose bacillus Calmette-Guérin maintenance therapy every 3 months or 6 months: two-year results of URO-BCG-4 multicenter study

OBJECTIVES

To assess bacillus Calmette-Guérin maintenance treatment schedule for non-muscle invasive bladder cancer at 2 years, using one-third of the full dose and fewer instillations every 3 months or 6 months.

METHODS

This was a prospective, randomized, multicenter study. All patients had an intermediate- or high-risk non-muscle invasive bladder cancer. They received three weekly instillations of one-third dose bacillus Calmette-Guérin every 6 months (group I) and two weekly instillations every 3 months (group II) during 3 years. In the two schedules we assessed efficacy, tolerance, leukocyturia and prostate-specific antigen.

RESULTS

No significant difference was observed between the two groups for recurrence at 6, 12 or 18 months. At 2 years, tumor recurrence was observed in 10.9% and muscle invasion in 2.9% of cases. Bacillus Calmette-Guérin tolerance was comparable - the adverse events score was 0.8 in group I and 1 in group II (P = 0.242). No statistical correlation was observed between the adverse events score over 2 years, either for leukocyturia (P = 0.8891) or prostate-specific antigen level (P = 0.7155). Leukocyturia level was not significantly associated with tumor recurrence or progression.

CONCLUSION

One-third dose maintenance bacillus Calmette-Guérin is effective with no impact on tumor recurrence or muscle invasion. Furthermore, there seems to be no difference in tumor response or side-effects between patients receiving two or three maintenance instillations every 3 months or 6 months. In clinical practice, the use of leukocyturia or total prostate-specific antigen levels do not appear to be useful in predicting bacillus Calmette-Guérin toxicity.

Comparable effect with minimal morbidity of low-dose Tokyo 172 strain compared with regular dose Connaught strain as an intravesical bacillus Calmette-Guérin prophylaxis in nonmuscle invasive bladder cancer: Results of a randomized prospective comparison

AIM

The aim was to compare patients' morbidity and response of bacillus Calmette-Guérin (BCG) prophylaxis after the intravesical instillation of low-dose Tokyo 172 strain and regular dose Connaught strain in patients with nonmuscle invasive bladder cancer (NMIBC).

PATIENTS AND METHODS

This was a randomized, active-controlled, open-label, monocenter study. Thirty-eight, NMIBC patients were treated sequentially, in a random order, with low-dose Tokyo 172 strain and regular dose Connaught strain, receiving each therapy for 6 weeks. A total of 18 and 20 patients were randomly assigned to a Tokyo 172 strain arm and a Connaught strain arm, respectively. Complication, morbidity, and recurrence-free survival (RFS) after each treatment were compared.

RESULTS

There was no significant difference in the 1-year RFS rate in patients treated with Tokyo 172 strain and Connaught strain (72.2% vs. 83.5%, respectively; P = 0.698). There were no significant differences in adverse events between the arms. Severe adverse events (>Grade 3) were seen in 15% of the Connaught strain group while no severe adverse events were observed as a result of Tokyo 172 strain.

CONCLUSION

Our results indicated that low-dose Tokyo 172 strain decreased adverse events although it was not significant, and the RFS difference was not statistically significant between the two arms. Further investigation is warranted.

Immunotherapy of genitourinary malignancies

Most cancer patients are treated with some combination of surgery, radiation, and chemotherapy. Despite recent advances in local therapy with curative intent, chemotherapeutic treatments for metastatic disease often remain unsatisfying due to severe side effects and incomplete long-term remission. Therefore, the evaluation of novel therapeutic options is of great interest. Conventional, along with newer treatment strategies target the immune system that suppresses genitourinary (GU) malignancies. Metastatic renal cell carcinoma and non-muscle-invasive bladder caner represent the most immune-responsive types of all human cancer. This review examines the rationale and emerging evidence supporting the anticancer activity of immunotherapy, against GU malignancies.

Intravesical therapy for bladder cancer

IMPORTANCE OF THE FIELD

Although transurethral resection of bladder tumor (TURBT) is effective therapy, up to 45% of patients will have a recurrence within 1 year after TURBT alone. Further, there is a 3 - 15% risk of tumor progression to muscle invasive and/or metastatic cancer. Depending on patient and tumor characteristics, a number of patients may benefit from some form of intravesical therapy. Adjuvant therapy is effective in avoiding post-TURBT implantation of tumor cells, eradicating residual disease, preventing tumor recurrence, and to delay or reduce tumor progression through direct cytoablation or immunostimulation.

AREAS COVERED IN THIS REVIEW

The role of risk assessment in the management of nonmuscle invasive bladder cancer (NMIBC) and the indications for the use of intravesical agents are discussed. Findings from major randomized clinical trials on BCG, interferon and various chemotherapeutic agents are summarized; key aspects of drug pharmacology, drug efficacy, side effects, and toxicity are also covered.

WHAT THE READER WILL GAIN

The reader will gain a basic understanding of the role of risk assessment in determining the need for intravesical therapy, as well as an overview of the different types of agents in use in the United States today.

TAKE HOME MESSAGE

The type of intravesical therapy used is based on the risk groups as noted in the European prognostic tables. Bacillus Calmette-Guerin (BCG) is the most commonly used first-line agent immunotherapeutic agent for prophylaxis and treatment of carcinoma in situ and high-grade bladder cancer. Other immunotherapeutic options include the interferons, interleukins 2 and 12, and tumor necrosis factor, all of which have activity in BCG refractory patients, although with low durable remission rates. Studies have shown that chemotherapy prevents recurrence but not progression. The available data on intravesical chemotherapy do not indicate that any single agent currently in use is clearly better than any other. Therefore, the selection of a chemotherapeutic agent is usually based on cost, toxicity, and availability as well as on physician preference and experience.

The safety and efficacy of different doses of bacillus Calmette Guérin in superficial bladder transitional cell carcinoma

OBJECTIVES

To conduct a trial using three different doses of bacillus Calmette-Guérin (BCG) to determine whether lowering the dose of BCG could reduce toxicity without compromising its efficacy in the treatment of superficial bladder cancer.

METHODS

From July 2002 to June 2005, 152 patients with superficial bladder cancer entered the trial. The patients were randomized to receive three different doses of BCG: 40, 80, and 120 mg. There were no significant differences in clinical and pathologic characteristics among the three groups. Twenty-four patients could not be followed to the end of the study because of poor compliance. At completion of the study, 40 patients could be evaluated in group A (40 mg), 48 in group B (80 mg), and 40 in group C (120 mg).

RESULTS

After treatment patients were evaluated for a mean follow-up period of 36 months (range 18 to 52 months). No significant difference in recurrence rate (20% versus 25% versus 20% respectively; P >0.05) was observed among the groups, and no progression of the disease was seen. Significant differences were observed among groups A, B, and C in local toxicity (30% versus 41.7% versus 70%, respectively; P <0.01). Systemic toxicity was more common in group C compared with groups B and A (P <0.01).

CONCLUSIONS

Reduction in the dose of intravesical BCG can reduce the toxicity associated with the treatment of superficial bladder cancer without affecting the efficacy of therapy.

Advances in the management of superficial bladder cancer

Given its high tendency to recur, coupled with an ever-present possibility to progress to potentially life-threatening muscle-invasive disease, superficial bladder cancer remains a challenging clinical problem. Optimal management begins with early detection and accurate risk assessment through careful attention to clinical features, aided by an emerging array of urinary markers and molecular characterizations. Prevention of recurrence requires the sequential application of tools to completely remove all visible disease, avert reimplantation during surgical resection, ablate microscopic foci, and prevent the emergence of new primary tumors amidst a field of carcinogen-exposed urothelium. Previously standard adjunctive intravesical chemo- and immunotherapies are enjoying new vitality as optimization strategies, new drugs, and rational drug combinations provide the potential for improved efficacy with reduced toxicity. New technological advances such as fluorescence-aided cystoscopy, microwave chemothermotherapy, and electromotive chemotherapeutic drug delivery offer further hope for better outcomes even for disease previously refractory to conservative measures. Yet despite these advances, aggressive surgical management involving bladder removal continues to be an indispensable life-saving maneuver that must be considered in all high-risk cases that fail to promptly respond to other measures.

The management of superficial transitional cell carcinoma of the bladder

Superficial transitional cell carcinomas (TCC) of the urinary bladder, defined as those that are restricted to the mucosa or the lamina propria, represent a common condition with a wide spectrum of biologic significance. High-grade superficial TCC, particularly in the presence of lamina propria invasion, has a significant risk of occult or subsequent progression to muscle-invasive or metastatic disease. Such high-risk lesions merit aggressive therapy with repeat resection followed by intravesical therapy, usually in the form of bacille Calmette-Guérin. Criteria for failure of intravesical therapy are not well defined, but persistent cytologic or cystoscopic abnormalities at 6 months are worrisome. Salvage intravesical therapy may sometimes be successful, but early cystectomy should be strongly considered, especially in younger patients. Close surveillance of patients with high-risk superficial TCC is essential.

Bacillus Calmete-Guérin plus interferon-alpha2B intravesical therapy maintains an extended treatment plan for superficial bladder cancer with minimal toxicity

Bacillus Calmette-Guérin (BCG) and interferon-alpha2B (IFN-alpha2B) have both been individually used for the intravesical treatment of superficial bladder cancer. We report our experience on the therapeutic efficacy and toxicity of combined intravesical BCG plus IFN-alpha2B for treating superficial bladder cancer, including patients failing previous BCG therapy. Thirty-two patients with superficial bladder cancer underwent 6 weekly treatments with full-, one-third, or one-tenth-dose of BCG plus 50 or 100 MU of IFN-alpha2B based on prior BCG exposure and tolerance. Patients with no evidence of disease proceeded onto maintenance therapy of 3 weekly treatments at 3 months followed by 2 additional maintenance cycles given 6 months apart. Response was assessed by cystoscopy/biopsy every 3 months after treatment. Before BCG plus IFN-alpha2B treatment, 20 patients (63%) had previously failed intravesical BCG therapy, 27 (84%) had aggressive disease (stage T1, grade 3, or carcinoma in situ), 27 (84%) had recurrent disease, 14 (44%) had multifocal disease, and 6 (19%) had disease of over 4 years duration. At median follow-up of 22 months, 21 patients (66%) remain disease-free and 11 patients (34%) had disease-recurrence. Nineteen of 32 patients (59%) were disease-free after the initial induction cycle. Six of 11 patients 55% ultimately failing combination therapy did so at the first 3 to 4 month evaluation. Four of 7 patients (57%) benefited from salvage re-induction therapy. Of the 20 patients previously treated with BCG, 12 patients (60%) remain disease-free. Combination BCG plus IFN-alpha2B intravesical therapy was well tolerated. Combination intravesical BCG plus IFN-alpha2B is an effective and tolerable alternative for patients with superficial bladder cancer, including those patients in whom intravesical BCG therapy had previously failed. Benefits of this combination therapy may include potentially less morbidity, improved clinical efficacy, and in the long term, fewer patients undergoing radical therapy. However, radical treatment options should be pursued for early failures of this combination regimen in those patients with risk factors for recurrence and progression.

Ectopic expression of von Hippel–Lindau tumor suppressor induces apoptosis in 786-O renal cell carcinoma cells and regresses tumor growth of 786-O cells in nude mouse

The von Hippel-Lindau (VHL) is a known tumor suppressor that binds to alpha-subunits of hypoxia-inducible factors and induces ubiquitin-mediated degradation of the protein in an oxygen-dependent manner. VHL is also involved in the regulation of tumor angiogenesis, glycolysis, cell cycle regulation, and apoptosis. In the present study, we showed that ectopic expression of VHL induces apoptosis in renal cell carcinoma 786-O cells which contain only the mutant VHL, evidenced by TUNEL assay and DAPI staining. Furthermore, biochemical studies indicated that expression of VHL in 786-O cells results in both PARP and CPP32 cleavage, suggesting that VHL-induced apoptosis in 786-O cells is caspase dependent. Moreover, we also observed that apoptosis induced by ectopic VHL expression was associated with up-regulation of p27 as well as Bax, implicating the roles of these two proteins in VHL-induced apoptosis. The up-regulation of p27 and Bax by VHL was specific since we did not detect any changes in the level of other apoptotic factors including Fas and Bcl2 by the expression of VHL. We next examined the effect of VHL expression on the tumor growth of 786-O renal cell carcinoma cells in nude mouse. The results showed that injection of Ad.VHL adenovirus regresses the tumor growth of 786-O cells in nude mouse. The analysis by TUNEL assay as well as DAPI staining of 786-O tumors injected with Ad.VHL showed clear evidence of apoptosis. These results suggest that ectopic VHL expression induces apoptotic response in 786-O VHL mutant cells both in vitro and in vivo.

Low dose BCG as adjuvant therapy for superficial bladder cancer and literature review

BACKGROUND

Bacillus Calmette-Guerin (BCG) at low doses has long been employed as prophylactic and therapeutic treatment for superficial cancer of the urinary bladder, aiming at reducing toxicity while maintaining efficacy. A retrospective review was reported, together with a review of the literature with respect to a low dose BCG regimen.

METHODS

Forty-five consecutive patients with superficial bladder cancer (Ta or T1) with one or more of the appropriate criteria (grade above 1, stage above a, size >1 cm, multiple or recurrent), after complete transurethral resection, received 27 mg Connaught strain BCG weekly for 6 weeks. There was no maintenance therapy. Patients were evaluated with urine cytology and cystoscopy. Recurrence, progression and death were analysed.

RESULTS

With a median follow up of 14 (range 3-61) months, 24 (53%) of the 45 patients responded to one course of 6 weekly BCG without recurrence. A further group of 13 (29%) patients responded to a second course of BCG on recurrence. Disease progressed in one (2.2%) patient. Two (4.4%) patients died of an unrelated condition. There was no disease specific mortality. Side-effects were common but well tolerated, with only two (4.4%) cases of treatment interruption.

CONCLUSIONS

Low dose BCG could be an alternative option of adjuvant therapy for superficial bladder cancer with acceptable toxicity and good compliance.

Current use and questions concerning intravesical bladder cancer group for superficial bladder cancer

Bacille Calmette-Guerin (BCG) is the most effective therapy for CIS of the bladder. Although several series have shown a decrease in recurrence and progression of T1 tumor, this effect is temporary. More than one half of patients with T1 tumors treated with BCG will progress over the longterm. A second course of BCG is indicated after an initial complete response. There is no definitive answer regarding the efficacy of maintenance therapy or the optimum dose of BCG. Randomized trials are needed to address these issues in a more conclusive manner. Phase III trials have shown that mitomycin C can be as effective as BCG in the management of papillary tumors; however, BCG is more effective in patients with CIS and high-risk superficial tumors.

Long-term follow-up of an EORTC randomized prospective trial comparing intravesical bacille Calmette-Guérin-RIVM and mitomycin C in superficial bladder cancer. EORTC GU Group and the Dutch South East Cooperative Urological Group. European Organisation for Research and Treatment of Cancer Genito-Urinary Tract Cancer Collaborative Group

OBJECTIVES

To determine long-term efficacy of intravesical mitomycin C (MMC) versus bacille Calmette-Guérin (BCG) in patients with superficial bladder cancer with regard to recurrences and progression.

METHODS

Patients with superficial bladder cancer (pTa, pT1, pTis) were treated with intravesical MMC (30 mg, weekly for 4 weeks, and thereafter monthly for 5 months) or BCG (weekly for 6 weeks).

RESULTS

Three hundred forty-four patients were eligible (171 in the BCG group, 173 in the MMC group). The median follow-up was 7.2 years. Toxicity was not significantly different between the two treatment groups. Efficacy of the two treatment policies was similar with regard to tumor recurrence. With regard to progression to invasive disease, MMC was more effective than BCG in patients without carcinoma in situ (CIS) (P = 0.006).

CONCLUSIONS

We can confirm the conclusions of other studies that intravesical treatment with 30 mg of MMC remains an effective treatment option that can also be used in high-risk patients. Like others, we could not confirm that a 6-week course of BCG is more effective in the prevention of tumor progression. Of the 33 patients with tumor progression after intravesical therapy, 20 died of bladder cancer, confirming that tumor progression after intravesical therapy carries a poor prognosis. In this study the difference in toxicity between BCG and MMC was not significant. When comparing studies with MMC and BCG, differences in treatment schedule and/or patient selection should be kept in mind.

Bacille Calmette-Guérin in superficial transitional cell carcinoma

The mechanisms by which BCG exerts its antitumour activity remain unclear. Attachment of BCG to the bladder via FN has been shown to be an important step in initiating its antitumorigenic activity. The mechanism(s) by which BCG operates requires LAK cells, BCG-activated killer cells, T lymphocytes (CD4) helper cells and CD8 suppressor/cytotoxic cells) and monocytes. The optimal route of administration is intravesical. The efficacy of a BCG vaccine depends on the viability, dose and strain. Differences in efficacy and side-effects have not been shown between different strains. Low-dose regimens successfully protect from recurrences, with fewer side-effects. The initial schedule of BCG is a course of six instillations in 6 weeks; when the patient fails this course, two possibilities arise. The first is maintenance therapy; response rates improve but there is more local and systemic toxicity. The second is a further 6-week course, and this seems most useful in those with a sustained response to the initial treatment. The clinical response to BCG therapy can be monitored using cytokine measurements or p53 determinations. Toxicity remains a major problem in BCG treatment and triple antituberculosis combination therapy should be given for 3 months in those with severe systemic side-effects. The use of prophylactic isoniazid is not recommend to decrease side-effects. The clinical results of BCG have been good, with success rates of 58-100%, with a minimal follow-up of one year in prophylaxis. BCG seems superior to intravesical therapy, but at the cost of inducing more adverse effects. BCG is not indicated for low- and intermediate-risk patients, in whom chemotherapy is the first choice. BCG can also be used to eliminate tumour after an incomplete TUR, or in patients who are unfit for surgery, with a 60-70% success rate. The primary and best treatment for CIS is intravesical BCG; encouraging results have been reported, with success rate of 42-83% after a minimal follow-up of one year. Although currently BCG seems to be the choice for high-risk superficial TCC, many questions remain unanswered, especially about the mechanism(s) of action, the optimal dose and clinical schedule.

Current recommendations for the management of bladder cancer. Drug therapy

Superficial transitional cell carcinoma of the bladder is a heterogeneous group of tumours, and prediction of disease outcome in an individual patient is still impossible. In low-risk patients the initial treatment [transurethral resection (TUR)] should be followed by no or only one immediate intravesical instillation with a chemotherapeutic drug to prevent a recurrence due to tumour cell implantation during TUR. Drug efficacy has been clearly demonstrated and adverse effects are very limited. Intermediate-risk patients should receive a course of additional intravesical instillations to reduce the recurrence rate with few adverse effects. All drugs seem to be equally effective, but the long term effects remain a question. In high-risk patients intravesical immunotherapy (BCG) should be given. Although toxicity is more pronounced, it is usually mild and adverse effects disappear after cessation of therapy. BCG (maintenance) therapy seems to be able to improve progression and ultimately tumour-related survival. It is important to know the advantages and disadvantages (adverse effects) of these treatment modalities to be able to individualise treatment as much as possible. The choice is difficult because several intravesical bladder cancer trials have not reached consensus on this. For patients with non-metastasised invasive bladder tumours chemotherapy can be given before (neoadjuvant) or immediately after (adjuvant) surgery or radiotherapy. Both strategies have some advantages and disadvantages. For both, however, efficacy still needs to be proven, and results of ongoing trials are needed. For metastasised or recurrent urothelial cell carcinoma MVAC (methotrexate, vinblastine, doxorubicin and cisplatin) chemotherapy remains the most effective treatment modality. Although initial response rates of between 40% and 70% can be achieved, most patients have a recurrence of their cancer. Moreover, toxicity of these drugs also is considerable and limiting. Leucopenia is responsible for the majority of grade III and IV toxicities and subsequent dose modifications. In case of toxic deaths, a leucopenic sepsis is usually the cause. Most other adverse effects are acceptable or can be treated.