Incidence of and mortality from Bacille Calmette-Guérin (BCG) infections after BCG instillation therapy

Cumulative incidence of and risk factors for BCG infection after adjuvant BCG instillations

OBJECTIVES

To investigate the cumulative incidence proportion of disseminated or local Bacillus Calmette-Guérin (BCG) infections after adjuvant BCG instillations in patients with non-muscle-invasive bladder cancer (NMIBC).

PATIENTS AND METHODS

We analysed the timing and occurrence of BCG infections and absolute and relative risk in relation to patient characteristics available in the Swedish nationwide database 'BladderBaSe 2.0'. The cumulative incidence proportion of a BCG infection was indicated by a reported diagnosis of tuberculosis (TB) in the patient registry or filing a prescription for tuberculostatic drugs.

RESULTS

The cumulative incidence proportion was 1.1% at the 5-year follow-up in 5033 patients exposed to adjuvant BCG instillations. The incidence rate was highest during the first 2 years after start of BCG instillations. Women had a lower risk than men (hazard ratio 0.23, 95% confidence interval 0.07-0.74). Age and calendar time at diagnosis, comorbidity, tumour risk group, previous medication with corticosteroids, immunosuppressive drugs, or time between transurethral resection of the bladder tumour and commencing the adjuvant BCG instillation were not associated with risk.

CONCLUSIONS

These data further supports that the overall risk of a BCG infection after BCG-instillation treatment for NMIBC is low. The great majority of infections occur in the first 2 years, calling for an awareness of the diverse symptoms of BCG infection during this period. We provide evidence for male sex as a risk factor; however, the statistical precision is low and with a risk of selection bias, making it difficult to rule out the other suggested risk factors without further studies with different approaches.

Prognostic Significance of HER2 Expression in Patients with Bacillus Calmette-Guérin-exposed Non-muscle-invasive Bladder Cancer

BACKGROUND

Guidelines recommend intravesical instillation of bacillus Calmette-Guérin (BCG) as the first-choice treatment for intermediate- and high-risk non-muscle-invasive bladder cancer (NMIBC). However, there is no therapeutic biomarker for predicting BCG efficacy, especially in high-risk cases with high failure rates. HER2 expression is considered a prognostic factor for bladder cancer.

OBJECTIVE

To elucidate the predictive value and significance of HER2 expression in patients with BCG-exposed NMIBC.

DESIGN, SETTING, AND PARTICIPANTS

A total of 454 patients with NMIBC were included. All patients started BCG intravesical instillation (1.2 × 108 CFU, strain D2PB302) 2-6 wk after transurethral resection of bladder tumor and received 19 treatments over a period of 1 yr. HER2 immunohistochemistry (IHC) results available for 314 patients.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The outcomes investigated were recurrence-free survival (RFS) and progression-free survival (PFS). Outcome relationships were explored using multivariable Cox regression and log-rank analysis.

RESULTS AND LIMITATIONS

In the IHC population, 35.7% of patients had HER2 overexpression (IHC score 2/3+). This group had a poor 5-yr RFS rate of 16.5%, in comparison to 68.0% in the group with low HER2 expression (p < 0.001). Patients with high-risk NMIBC and HER2 overexpression had the highest risk of BCG treatment failure, with 5-yr RFS and PFS rates of 19.0% and 58.2%, respectively. Conversely, HER2-negative (IHC score 0) patients with high-risk NMIBC experienced a long-term BCG benefit, with 5-yr RFS and PFS rates of 80.8% and 92.1%, respectively. Limitations include the retrospective study design and the limited details regarding BCG use.

CONCLUSIONS

HER2 was an independent predictor of poor BCG efficacy in NMIBC. Patients with high-risk NMIBC and HER2 overexpression had the highest risk of disease recurrence and progression after exposure to BCG. Anti-HER2 targeted therapies could be considered for these patients.

PATIENT SUMMARY

Measurement of blood levels of the protein HER2 can be used to predict outcomes after BCG (bacillus Calmette-Guérin) bladder therapy for patients with intermediate- or high-risk non-muscle-invasive bladder cancer. Measurement results for HER2 may help in guiding personalized treatment for these patients.

Invasive Mycobacterium bovis Infection Outside the Genitourinary Tract Following Bacille Calmette-Guerin Therapy for Non-muscle Invasive Bladder Cancer

Bladder cancer significantly impacts global health, particularly non-muscle-invasive bladder cancer (NMIBC), which is typically treated with transurethral resection of bladder tumor (TURBT) and intravesical Bacillus Calmette-Guérin (BCG) therapy. While there is evidence that BCG can effectively prevent tumor recurrence and progression, it can cause adverse effects, including disseminated infection, necessitating the exclusion of active tuberculosis and the assessment of immunosuppressive conditions before treatment. We present two cases of disseminated BCG infection. The first involves an 85-year-old male who developed an abscess in his right thigh post-BCG therapy, successfully treated with isoniazid (INH), ethambutol, and rifampin. The second case is a 63-year-old male who, three years post-BCG therapy and abdominal aortic aneurysm repair, developed a right psoas abscess and a mycotic aneurysm. He was also treated with ethambutol, INH, and rifampin, in addition to surgical intervention. Effective management of BCG-related infections requires early identification of Mycobacterium bovis, a multidisciplinary approach, thorough pre-treatment evaluations, and aggressive treatment strategies, including anti-tubercular drugs and surgical intervention as necessary.

Intermediate and high-risk non-muscle-invasive bladder cancer: an overview of epidemiology, burden, and unmet needs

Bladder cancer ranks among the most common cancers globally. At diagnosis, 75% of patients have non-muscle-invasive bladder cancer (NMIBC). Patients with low-risk NMIBC have a good prognosis, but recurrence and progression rates remain high in intermediate- and high-risk NMIBC, despite the decades-long availability of effective treatments for NMIBC such as intravesical Bacillus Calmette-Guérin (BCG). The present review provides an overview of NMIBC, including its burden and treatment options, and then reviews aspects that counteract the successful treatment of NMIBC, referred to as unmet treatment needs. The scale and reasons for each unmet need are described based on a comprehensive review of the literature, including insufficient adherence to treatment guidelines by physicians because of insufficient knowledge, training, or access to certain therapy options. Low rates of lifestyle changes and treatment completion by patients, due to BCG shortages or toxicities and adverse events as well as their impact on social activities, represent additional areas of potential improvement. Highly heterogeneous evidence for the effectiveness and safety of some treatments limits the comparability of results across studies. As a result, efforts are underway to standardize treatment schedules for BCG, but intravesical chemotherapy schedules remain unstandardized. In addition, risk-scoring models often perform unsatisfactorily due to significant differences between derivation and real-world cohorts. Reporting in clinical trials suffers from a lack of consistent outcomes reporting in bladder cancer clinical trials, paired with an under-representation of racial and ethnic minorities in many trials.

Clinical presentation of bacille Calmette-Guérin (BCG) infections after BCG instillation therapy

OBJECTIVES

To investigate the timing of the clinical presentation of various types of bacille Calmette-Guérin (BCG) infections in a Finnish population of patients with bladder cancer treated with BCG instillation therapy.

PATIENTS AND METHODS

We identified patients with a history of post-instillation BCG infection from 1996 to 2016 using the Finnish Cancer Registry and the Finnish National Infectious Diseases Registry. We categorised infections as systemic if the infection was found in the non-urogenital system and genitourinary (GU) if the infection affected the urogenital tract. We calculated the time interval between the last BCG instillation and the presentation of the infection. The infection was considered late if the time interval was ≥1 year.

RESULTS

A total of 100 patients with BCG infection were identified during the study period. In all, 39 (39%) infections presented as systemic and 61 (61%) were in the GU tract. The majority of the systemic infections presented rapidly after the last instillation, while five (13%) presented after a latency of ≥1 year. The presentation of GU infections was more heterogeneous, with 12 (20%) presenting as late infections.

CONCLUSION

This study confirms the concept of early and late infection types, especially among systemic infections. However, late infections appeared to be rarer than previously described. Urologists should be aware of the possibility of late BCG infection if patients develop symptoms even several years after the BCG regimen.