Complications of intravesical BCG therapy in non-muscle invasive bladder cancer: our tertiary care centre experience

Bacillus Calmette-Guérin pneumonitis after intravesical instillation: Report of two cases and a review of the literature

OBJECTIVE

Intravesical administration of bacillus Calmette-Guérin is standard adjuvant treatment of non-muscle invasive bladder cancer. In spite of the fact that this immunotherapy is locoregional, there are still risk of some complications.

METHODS

We describe two cases of systemic BCG infection after intravesical administration of BCG vaccine in patients with early stage of bladder cancer.

RESULTS

Both patients suffered from systemic BCG infection manifesting as BCG pneumonitis. After standard therapy with antituberculotic agents, both of them fully recovered.

CONCLUSION

BCG infection can occur as a rare but potentially serious complication of this treatment procedure. Gravity of this side effect and its specific therapy require prompt and right diagnosis.

Comparison of red and green light for treating non-muscle invasive bladder cancer in rats using singlet oxygen-cleavable prodrugs with PPIX-PDT

It has been 30 years since Photofrin-PDT was approved for the treatment of bladder cancer in Canada. However, Photofrin-PDT failed to gain popularity due to bladder complications. The PDT with red light and IV-administered Photofrin could permanently damage the bladder muscle. We have been developing a new combination strategy of PpIX-PDT with singlet oxygen-cleavable prodrugs for NMIBC with minimal side effects, avoiding damage to the bladder muscle layer. PpIX can be excited by either green (532 nm) or red (635 nm) light. Red light could be more efficacious in vivo due to its deeper tissue penetration than green light. Since HAL preferentially produces PpIX in tumors, we hypothesized that illuminating PpIX with red light might spare the muscle layer. PpIX-PDT was used to compare green and red laser efficacy in vitro and in vivo. The IC50 of in vitro PpIX-PDT was 18 mW/cm2 with the red laser and 22 mW/cm2 with the green laser. The in vivo efficacy of the red laser with 50, 75, and 100 mW total dose was similar to the same dose of green laser in reducing tumor volume. Combining PpIX-PDT with prodrugs methyl-linked mitomycin C (Mt-L-MMC) and rhodamine-linked SN-38 (Rh-L-SN-38) significantly improved efficacy (tumor volume comparison). PpIX-PDT or PpIX-PDT + prodrug combination did not cause muscle damage in histological analysis. Overall, a combination of PpIX-PDT and prodrug with 635 nm laser is promising for non-muscle invasive bladder cancer treatment.

BCG induced lower urinary tract symptoms during treatment for NMIBC-Mechanisms and management strategies

Non-muscle invasive bladder cancer (NMIBC) accounts for ~70-75% of total bladder cancer tumors and requires effective early intervention to avert progression. The cornerstone of high-risk NMIBC treatment involves trans-urethral resection of the tumor followed by intravesical Bacillus Calmette-Guerin (BCG) immunotherapy. However, BCG therapy is commonly accompanied by significant lower urinary tract symptoms (LUTS) including urinary urgency, urinary frequency, dysuria, and pelvic pain which can undermine treatment adherence and clinical outcomes. Despite this burden, the mechanisms underlying the development of BCG-induced LUTS have yet to be characterized. This review provides a unique perspective on the mechanisms thought to be responsible for the development of BCG-induced LUTS by focussing on the sensory nerves responsible for bladder sensory transduction. This review focuses on how the physiological response to BCG, including inflammation, urothelial permeability, and direct interactions between BCG and sensory nerves could drive bladder afferent sensitization leading to the development of LUTS. Additionally, this review provides an up-to-date summary of the latest clinical data exploring interventions to relieve BCG-induced LUTS, including therapeutic targeting of bladder contractions, inflammation, increased bladder permeability, and direct inhibition of bladder sensory signaling. Addressing the clinical burden of BCG-induced LUTS holds significant potential to enhance patient quality of life, treatment compliance, and overall outcomes in NMIBC management. However, the lack of knowledge on the pathophysiological mechanisms that drive BCG-induced LUTS has limited the development of novel and efficacious therapeutic options. Further research is urgently required to unravel the mechanisms that drive BCG-induced LUTS.

The relationship between BCG immunotherapy and oxidative stress parameters in patients with nonmuscle invasive bladder cancer

INTRODUCTION

Environmental chemicals have been associated with the regulation of oxidative stress markers, which have the potential for the development of bladder cancer. However, limited studies on the function of oxidative stress parameters and nonmuscle invasive bladder cancer (NMIBC) in therapy response are available. Here we studied the oxidative stress parameters in response to BCG immunotherapy in NMIBC patients.

MATERIAL AND METHODS

A total of 120 patients with NMIBC and treatment with BCG were enrolled and categorized into 2 groups on BCG response, 50 patients were BCG-responsive (BCG-R) and 70 were BCG-nonresponsive (BCG-N). BCG-R have no evidence of tumor recurrence or advancement after 1 year of BCG immunotherapy, but BCG-N has a recurrence of tumor after 3 to 6 months cycles of BCG instillation, as determined by cystoscopy. In all groups, we measured the levels of oxidative stress markers- malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), and catalase (CAT).

RESULTS

The levels of oxidative stress markers viz. MDA, NO, and SOD in the BCG-N group were significantly higher (P < 0.001) than in the BCG-R group. Furthermore, the data demonstrated a significant correlation between oxidative stress marker and NMIBC T1 high grade and tumor size >2.5 cm. However, no statistically significant difference was found between studied groups with CAT.

CONCLUSION

The findings suggest that the carcinogenesis of NMIBC is associated with oxidative damage of biomolecules and indicates the involvement of oxidative stress markers in the development and recurrence of NMIBC.; Therefore, it is critical to ensure the management for T1 high grade and tumor size of >2.5 cm for antioxidant protection.

[Aortic Complications Related to Mycobacterium bovis after Intravesical Bacille Calmette-Guérin Therapy - a Systematic Review]

BACKGROUND

Aortic complications after intravesical Bacillus Calmette-Guérin (BCG) application are a rare complication of the treatment of non-muscle invasive bladder cancer. The aim of this systematic review was to perform a descriptive analysis of previously published studies and to discuss the particular challenges of diagnosis and treatment of this rare complication.

MATERIAL AND METHODS

A literature search was performed in PubMed (1949-2021) and Web of Science (1900-2021) using the search terms "mycobacterium" OR "bovis" OR "BCG" AND "aorta" OR "aneurysm". In a staged review process, publications with the following inclusion criteria were included in data analysis: original paper, full-text availability in English or German and aortic complication after intravesical BCG instillation. We focused on the analysis of BCG-specific medical history data as well as treatment strategies in relation to patient outcome and the occurrence of graft infections during follow-up.

RESULTS

A total of 60 individual cases were described in 55 published articles. BCG-induced mycotic aortic aneurysms can occur in all segments of the thoracoabdominal aorta, but the infrarenal aortic segment was most commonly affected (65% of cases). The most common configuration was saccular outpouchings (65%). Concomitant infections in other tissues were typical (65%). Patients with mycotic aneurysm presented with or without consecutive aortic rupture in 28% and 63%, respectively. Diagnosis was based on a combination of pathological and microbiological examinations. A common treatment algorithm was surgical infection treatment (85%) and antitubercular therapy (83%). Performed simultaneously, they resulted in a long-term survival of 81%. Graft infection after initial aortic repair with alloplastic material (n = 40) developed in ten patients (25%) during follow-up.

DISCUSSION

Diagnosis of mycotic aneurysms or vascular complications after intravesical BCG application is exceptionally challenging and a high level of suspicion is required. Diagnosis is based on obtaining sample material of affected regions and the combination of patient's history, clinical presentation and pathological or microbiological examinations. Currently, no consensus guideline for optimal medical treatment options of aortic complications secondary to BCG instillation exists. The combination of surgical treatment and supportive antitubercular therapy seems to achieve the best results. Since the risk of prosthetic infection after the use of alloplastic materials remains high (25%), we strongly suggest evaluating autologous or allogenic aortic replacement during initial aortic repair.