Comparison of Bacillus Calmette-Guérin Maintenance Therapy with Monthly Instillations and the Southwest Oncology Group Protocol in the Treatment of Non-muscle-invasive Bladder Cancer

BACKGROUND

Bacillus Calmette-Guérin (BCG) therapy using the Southwest Oncology Group (SWOG) maintenance protocol is the standard in non-muscle-invasive bladder cancer (NMIBC). Maintenance with monthly instillations is also widely used, but evidence comparing the two maintenance protocols is scarce.

OBJECTIVE

To compare monthly and SWOG instillation schedules in maintenance BCG therapy.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively identified patients with NMIBC treated with maintenance BCG according to either the monthly or the SWOG instillation regimen in two tertiary care centers in Finland between 2009 and 2019.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We compared discontinuation rates of the monthly and SWOG maintenance protocols due to toxicity, and recurrence and progression rates by protocols. Baseline characteristics were compared with the Wilcoxon rank sum test, chi-square test, and Fisher's exact test. The Kaplan-Meier method and Cox proportional hazards model were used to evaluate the discontinuation of BCG due to toxicity and oncological efficacy.

RESULTS AND LIMITATIONS

We identified 723 patients, of whom 545 (75%) and 178 (25%) received maintenance according to the monthly and SWOG protocols, respectively. The median follow-up time was 66 (interquartile range: 45-99) mo. In the monthly and SWOG groups, 131 (24%) and 50 (28%) patients, respectively, discontinued BCG due to toxicity, with no difference in a univariate or multivariate analysis (hazard ratio 1.01, 95% confidence interval [CI]: 0.73-1.40, p = 0.940). The 5-yr recurrence-free survival rates in the monthly and SWOG groups were 65% (95% CI: 61-69%) and 71% (95% CI: 64-79%, p = 0.370), respectively. The 5-yr progression-free survival rates were 89% (95% CI: 86-92%) and 91% (95% CI: 86-96%, p = 0.240), respectively.

CONCLUSIONS

Monthly maintenance is a comparable alternative to the SWOG protocol.

PATIENT SUMMARY

In this study, we compared two schedules of intravesical bacillus Calmette-Guérin (BCG) treatment used in the treatment of non-muscle-invasive bladder cancer. We found that there were no significant differences between the two instillation schedules in terms of tolerability or efficacy.

Cut-off values to evaluate exercise-induced asthma in eucapnic voluntary hyperventilation test for children

BACKGROUND AND AIM

The eucapnic voluntary hyperventilation (EVH) testing is a diagnostic tool for diagnostics of exercise-induced bronchoconstriction; while the testing has become more common among children, data on the test's feasibility among children remain limited. Our aim was to investigate EVH testing feasibility among children, diagnostic testing cut-off values, and which factors affect testing outcomes.

METHODS

We recruited 134 patients aged 10-16 years with a history of exercise-induced dyspnoea and 100 healthy control children to undergo 6-min EVH testing. Testing feasibility was assessed by the children's ability to achieve ≥70% of the target minute ventilation of 30 times forced expiratory volume in 1 s (FEV1). Bronchoconstriction was assessed as a minimum of 8%, 10%, 12%, 15% or 20% fall in FEV1. Patient characteristics were correlated with EVH outcomes.

RESULTS

Overall, 98% of the children reached ≥70%, 88% reached ≥80%, 79% reached ≥90% and 62% reached ≥100% of target ventilation in EVH testing; of children with a history of exercise-induced dyspnoea, the decline percentages were as follows: 24% (≥8% fall), 17% (≥10% fall), 10% (≥12% fall), 6% (≥15% fall) and 5% (≥20% fall) in FEV1, compared to 11%, 4%, 3%, 1% and 0% among the healthy controls, respectively. Healthy controls and boys performed testing at higher ventilation rates (p < .05).

CONCLUSION

Eucapnic voluntary hyperventilation testing is feasible among children aged 10-16 years and has diagnostic value in evaluating exercise-induced dyspnoea among children. A minimum 10% fall in FEV1 is a good diagnostic cut-off value. Disease status appears to be important covariates.

Human bocaviruses and paediatric infections

Human bocavirus 1 (HBoV1), belonging to the Parvoviridae family, was discovered in 2005, in nasopharyngeal samples from children with respiratory tract infections. Three additional bocaviruses, HBoV2-4, were discovered in 2009-10. These viruses have mainly been found in faecal samples and their role in human diseases is still uncertain. HBoV1 causes a wide spectrum of respiratory diseases in children, including common cold, acute otitis media, pneumonia, bronchiolitis, and asthma exacerbations. HBoV1 DNA can persist in airway secretions for months after an acute infection. Consequently, acute HBoV1 infection cannot be diagnosed with standard DNA PCR; quantitative PCR and serology are better diagnostic approaches. Because of their high clinical specificity, diagnostic developments such as HBoV1 mRNA and antigen detection have shown promising results. This Review summarises the knowledge on human bocaviruses, with a special focus on HBoV1.