Antibiotic Prescriptions in Lung Cancer and Melanoma Populations: Differences With Potential Clinical Implications in the Immunotherapy Era

Emerging insights into the gut microbiota as a key regulator of immunity and response to immunotherapy in hepatocellular carcinoma

The gut microbiota, a complex microbial ecosystem closely connected to the liver via the portal vein, has emerged as a critical regulator of liver health and disease. Numerous studies have underscored its role in the onset and progression of liver disorders, including alcoholic liver disease, metabolic dysfunction-associated steatotic liver disease (MASLD), metabolic dysfunction-associated steatohepatitis (MASH), liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). This review provides a comprehensive overview of current insights into the influence of the gut microbiota on HCC progression, particularly its effects on immune cells within the HCC tumor microenvironment (TME). Furthermore, we explore the potential of gut microbiota-targeted interventions, such as antibiotics, probiotics, prebiotics, and fecal microbiota transplantation (FMT), to modulate the immune response and improve outcomes of immunotherapy in HCC. By synthesizing insights from recent studies, this review aims to highlight microbiota-based strategies that may enhance immunotherapy outcomes, advancing personalized approaches in HCC treatment.

Examining the impact of treatment guidelines on outpatient antibiotic prescription trends at a cancer center in Pakistan

Objective

To assess the impact of treatment guidelines on the trends of outpatient antibiotic prescription among pediatric and adult patients at a cancer center in Pakistan.

Design

Retrospective observational study conducted between July 1st 2018 and July 31st 2023.

Methods

We determined the indication for antibiotics and the frequency of guideline-discordant prescriptions for upper respiratory tract infection (URTI), lower respiratory tract infection (LRTI), urinary tract infection (UTI), and diarrhea. The χ2 test was used to assess the impact of treatment guidelines on antibiotics prescribed for these indications.

Results

The top indications for antibiotic prescription were skin and skin structure infection (SSSI) (n = 5159; 21.5%), URTI (n = 2760; 11.5%) and UTI (n = 2686; 11.2%). Amoxicillin-clavulanate (n = 7964; 33.3%), was the most frequently prescribed antibiotic. A large proportion of antibiotic prescriptions for URTI, diarrhea, UTI, and LRTI were either inappropriate (n = 6695; 86.5%) or unnecessary (n = 5534; 71.5%). Results revealed a statistically significant decline in the proportion of inappropriate antibiotics for UTI (91.3% vs 84.0%; P ≤ .001) and diarrhea (92.6% vs 87.0%; P = .031) and unnecessary antibiotics for diarrhea (90.2% vs 83.2%; P = .016) with the introduction of treatment guidelines. We noted a higher proportion of unnecessary prescriptions for LRTI (41.7% vs 31.7%; P = .003) and inappropriate antibiotics for UTI (95.1% vs 87.4%; P = .011) for pediatric patients.

Conclusion

Misuse of outpatient antibiotics is common. Diarrhea, URTI, UTI, and LRTI are high-priority conditions for outpatient oncology-focused prescriber education and stewardship interventions.

Association Between Antibiotic and Outcomes of Chemoimmunotherapy for Extensive-Stage Small Cell Lung Cancer: A Multicenter Retrospective Study of 132 Patients

INTRODUCTION

To evaluate the impact of antibiotic (ATB) exposure on the outcome of chemoimmunotherapy in patients with extensive-stage small cell lung cancer (ES-SCLC).

METHODS

In this multicenter retrospective study, 132 patients with ES-SCLC who received chemoimmunotherapy were included from three hospitals in China. Patients receiving ATB within 30 days prior to initiating ICI therapy (p-ATB) and those receiving concurrent ICI therapy until cessation (c-ATB)were compared to those who did not (n-ATB). Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and immune-related adverse events (irAEs) were assessed. To avoid immortal time bias, c-ATB was analyzed as a time-dependent covariate in the Cox proportional hazards model.

RESULTS

Among the 132 patients, 25 were included in the p-ATB group and 26 in the c-ATB group, while 81 patients were categorized in the n-ATB group. Multivariate analysis revealed no significant differences in PFS (aHR = 1.028, 95% CI: 0.666-1.589, p = 0.900) and OS (aHR = 0.957, 95% CI: 0.549-1.668, p = 0.877) between the p-ATB and n-ATB groups. Similarly, p-ATB had no significant impact on ORR (p = 0.510) or irAEs (p = 0.516). The use of c-ATB had no significant effect on either PFS (aHR: 1.165, 95% CI: 0.907-1.497; p = 0.232) or OS (aHR: 1.221, 95% CI: 0.918-1.624; p = 0.171) by multivariate analysis.

CONCLUSIONS

p-ATB has no significant impact on PFS, OS, ORR, or the incidence of irAEs in ES-SCLC patients receiving chemoimmunotherapy. Similarly, c-ATB does not seem to affect PFS or OS.

Impact of Antibiotic on Efficacy and Adverse Reactions of Chemoimmunotherapy in Non-small Cell Lung Cancer Patients: A Retrospective Cohort Study

BACKGROUND

This study aimed to evaluate the impact of antibiotic exposure on efficacy and adverse reactions in non-small cell lung cancer (NSCLC) patients receiving chemoimmunotherapy, and to explore any specific associations on the basis of antibiotic class.

METHODS

A retrospective study was conducted on NSCLC patients who received chemoimmunotherapy in two Shandong hospitals between January 2018 and October 2023. The association between antibiotic exposure and progression-free survival (PFS), overall survival (OS), objective response rate (ORR) and incidence of immune related adverse reactions (irAE) of patients were evaluated.

RESULTS

Of the 316 patients, 134 (42.41%) received antibiotics (ATB group), and 182 (57.59%) did not (N-ATB group). There was no significant difference in PFS (aHR = 1.009, 95% CI: 0.770-1.323; p = 0.946) or OS (aHR = 1.420, 95% CI: 0.986-2.047; p = 0.060) between ATB and N-ATB groups. The impact on efficacy was related to the type of antibiotic. β-Lactams (aHR = 1.737, 95% CI: 1.148-2.629; p = 0.009), in particular β-lactam/β-lactamase inhibitor combinations (BLBLIs) (aHR = 1.885, 95% CI: 1.207-2.944, p = 0.005) were associated with poorer OS. However, quinolones (aHR = 1.192, 95% CI: 0.861-1.650; p = 0.291) were not associated with OS. The incidence of irAEs was not significantly different between ATB and N-ATB groups (p = 0.073), but was higher with BLBLIs (p = 0.013).

CONCLUSIONS

In NSCLC patients receiving chemoimmunotherapy, no significant difference was observed in efficacy and incidence of irAEs between the ATB and the n-ATB groups. In antibiotic class analysis, β-lactams and specifically BLBLIs were observed to be associated with worse OS.

Assessing the impact of COVID-19 on prescription patterns and antibiotic use: Insights from three military health facilities

BACKGROUND

The COVID-19 pandemic disrupted health systems globally and there are suggestions it impacted antibiotics prescribing patterns in clinical practice.

OBJECTIVES

This study aimed to assess the effects of the COVID-19 pandemic on the prescribing patterns in three Nigerian military health facilities and investigate the factors associated with antibiotic prescriptions.

METHODS

This was a two-year cross-sectional retrospective study. Three hospitals and a total of 11,590 prescriptions were purposively and conveniently sampled respectively. The World Health Organisation (WHO) and International Network of Rational Use of Drugs (INRUD) prescribing indicators were used to assess for polypharmacy, injection use, use of antibiotics, use of generic drugs and prescriptions from essential drug lists for the periods of the pandemic and before the pandemic. Indicators from both periods were compared for statistical significance using the independent t-test. Generalized linear modelling was applied to assess the factors associated with antibiotic prescriptions. The relationship between the receipt of antibiotics and independent variables was presented using incident risk ratios (IRR).

RESULTS

Our findings showed that all five WHO/INRUD prescribing indicators were above the reference limit for the two-year study period. The study found there was a significant statistical difference between the COVID- and non-COVID-19 periods, with polypharmacy and antibiotic use indicators elevated during the pandemic compared to the latter. COVID-19 (IRR = 1.09), comorbidity (IRR = 1.74), pregnancy (IRR = 0.93), out-of-pocket payments (IRR = 1.10) and the inpatient department (IRR = 1.51) were associated with antibiotic prescriptions.

CONCLUSIONS

This provides insight on impact of the pandemic on prescription patterns and advocates for stewardship programs in clinical settings to ensure the rational use of drugs.

The Effects of Antibiotics on the Development and Treatment of Non-Small Cell Lung Cancer

There have been studies on antibiotic use concerning lung cancer and its potential impact on carcinogenesis and microbiome. However, subsequent research has failed to support these associations consistently. In terms of the potential carcinogenic of antibiotics on lung cancer, the available evidence has not been sufficient to draw any definitive conclusions. Maintaining immune homeostasis and preventing pathogen invasion is critically dependent on the microbiome. The subtle balance of the body microbiota, including the lungs, is susceptible to disruption by antibiotic use. There is an association between disruptions of the lung microbiome and respiratory diseases, including lung cancer, and decreased efficacy of treatments. Patients with lung cancer are often indicated for antibiotic treatment due to respiratory infections or other comorbidities. Pulmonary infections in the area of undetected lung tumors are not uncommon. They can be an early sign of malignancy, which may explain the association between antibiotic use and lung cancer diagnosis. Antibiotic use can also affect the effectiveness of immune checkpoint inhibitor therapy. Studies suggest that antibiotic use can impair the efficacy of immune checkpoint inhibitor therapy in lung cancer patients, particularly around the time when treatment is initiated. These findings require further study, understanding underlying mechanisms, and identifying microbiota signatures associated with treatment response.