Secondary Infections After Diagnosis of Severe Radiation Pneumonitis (SRP) Among Patients With Non-small Cell Lung Cancer: Pathogen Distributions, Choice of Empirical Antibiotics, and the Value of Empirical Antifungal Treatment

Impact on hospitalization and infection patterns of advanced lung cancer with lower respiratory tract infections: Targeted therapy vs. chemoradiotherapy

Lung cancer is a prevalent and highly lethal disease often complicated by lower respiratory tract infections. Microbial patterns in these infections vary based on treatment modalities. The present study explored the impact of lung cancer treatments on pathogens and clinical characteristics in the presence of lower respiratory tract infections to inform antimicrobial drug selection. A retrospective analysis was performed that included data from 93 patients diagnosed with advanced lung cancer and lower respiratory tract infections between January 2019 and December 2021. Patients were divided into the targeted therapy and chemoradiotherapy groups. Clinical, nutritional, biochemical, infection and pathogenetic indicators were compared. Of the 93 cases, 24 were in the targeted therapy group and 69 were in the chemoradiotherapy group. Pathological type and hospitalization duration differed significantly (P<0.05), but age, sex, smoking history, alcohol consumption and underlying diseases did not (P>0.05). Lymphocyte counts differed (P<0.05), while body mass index, albumin, hemoglobin, alanine aminotransferase and creatinine levels, erythrocyte sedimentation rate, hypersensitive C-reactive protein and procalcitonin levels, and the percentage of neutrophils did not (P>0.05). Pathogenetic testing was negative in 15 patients and positive in 78 patients, with Gram-negative bacteria (61.77%), fungi (17.65%) and viruses (11.76%) predominant in the targeted therapy group. In the chemoradiotherapy group, Gram-negative bacteria (47.46%), fungi (28.81%) and viruses (16.95%) were also more prevalent. Candida albicans was the most frequent fungal infection in both groups, and mixed infections were common (50% in targeted therapy and 73.92% in chemoradiotherapy). The chemoradiotherapy group had significantly more mixed infections (P<0.05). Overall, common pathogens in both groups included Gram-negative bacteria, fungi and viruses. Chemoradiotherapy patients experienced longer hospital stays and a higher incidence of mixed infections, predominantly involving Gram-negative bacteria and fungi. The results provide valuable insights into the rational selection of empirical antibiotics and antifungals for critically ill patients with lung cancer and lower respiratory tract infections in targeted therapy or chemoradiotherapy.

Microarray analysis of hub genes, non-coding RNAs and pathways in lung after whole body irradiation in a mouse model

PURPOSE

Previous research has highlighted the impact of radiation damage, with cancer patients developing acute disorders including radiation induced pneumonitis or chronic disorders including pulmonary fibrosis months after radiation therapy ends. We sought to discover biomarkers that predict these injuries and develop treatments that mitigate this damage and improve quality of life.

MATERIALS AND METHODS

Six- to eight-week-old female C57BL/6 mice received 1, 2, 4, 8, 12 Gy or sham whole body irradiation. Animals were euthanized 48 h post exposure and lungs removed, snap frozen and underwent RNA isolation. Microarray analysis was performed to determine dysregulation of messenger RNA (mRNA), microRNA (miRNA), and long non-coding RNA (lncRNA) after radiation injury.

RESULTS

We observed sustained dysregulation of specific RNA markers including: mRNAs, lncRNAs, and miRNAs across all doses. We also identified significantly upregulated genes that can indicate high dose exposure, including Cpt1c, Pdk4, Gdf15, and Eda2r, which are markers of senescence and fibrosis. Only three miRNAs were significantly dysregulated across all radiation doses: miRNA-142-3p and miRNA-142-5p were downregulated and miRNA-34a-5p was upregulated. IPA analysis predicted inhibition of several molecular pathways with increasing doses of radiation, including: T cell development, Quantity of leukocytes, Quantity of lymphocytes, and Cell viability.

CONCLUSIONS

These RNA biomarkers might be highly relevant in the development of treatments and in predicting normal tissue injury in patients undergoing radiation treatment. We are conducting further experiments in our laboratory, which includes a human lung-on-a-chip model, to develop a decision tree model using RNA biomarkers.

Clinical outcomes of antimicrobial resistance in cancer patients: a systematic review of multivariable models

BACKGROUND

Infections are major causes of disease in cancer patients and pose a major obstacle to the success of cancer care. The global rise of antimicrobial resistance threatens to make these obstacles even greater and hinder continuing progress in cancer care. To prevent and handle such infections, better models of clinical outcomes building on current knowledge are needed. This internally funded systematic review (PROSPERO registration: CRD42021282769) aimed to review multivariable models of resistant infections/colonisations and corresponding mortality, what risk factors have been investigated, and with what methodological approaches.

METHODS

We employed two broad searches of antimicrobial resistance in cancer patients, using terms associated with antimicrobial resistance, in MEDLINE and Embase through Ovid, in addition to Cinahl through EBSCOhost and Web of Science Core Collection. Primary, observational studies in English from January 2015 to November 2021 on human cancer patients that explicitly modelled infection/colonisation or mortality associated with antimicrobial resistance in a multivariable model were included. We extracted data on the study populations and their malignancies, risk factors, microbial aetiology, and methods for variable selection, and assessed the risk of bias using the NHLBI Study Quality Assessment Tools.

RESULTS

Two searches yielded a total of 27,151 unique records, of which 144 studies were included after screening and reading. Of the outcomes studied, mortality was the most common (68/144, 47%). Forty-five per cent (65/144) of the studies focused on haemato-oncological patients, and 27% (39/144) studied several bacteria or fungi. Studies included a median of 200 patients and 46 events. One-hundred-and-three (72%) studies used a p-value-based variable selection. Studies included a median of seven variables in the final (and largest) model, which yielded a median of 7 events per variable. An in-depth example of vancomycin-resistant enterococci was reported.

CONCLUSIONS

We found the current research to be heterogeneous in the approaches to studying this topic. Methodological choices resulting in very diverse models made it difficult or even impossible to draw statistical inferences and summarise what risk factors were of clinical relevance. The development and adherence to more standardised protocols that build on existing literature are urgent.

The impact of antibiotic selection and interval time among advanced non-small cell lung cancer patients receiving prior antibacterial treatment and first-line chemotherapy

BACKGROUND

To determine whether antibiotic use before chemotherapy is associated with chemotherapy responses and patient outcomes among NSCLC patients and define the optimal interval between chemotherapy initiation and antibiotic treatment.

MATERIALS AND METHODS

One thousand four hundred and four advanced NSCLC patients receiving first-line platinum-based doublets therapy were retrospectively analyzed. Kaplan-Meier curve evaluated the impact of antibiotic use and type of antibiotics on the survival of patients. The factors affect the patient's prognosis were further confirmed by Cox regression. The optimal interval between antibiotic treatment and the initiation of chemotherapy was determined by the X-tile program.

RESULTS

NSCLC patients of 33.5% advanced underwent broad-spectrum antibiotic treatment prior to chemotherapy. In the chemotherapy only (Chemo) and chemotherapy plus antiangiogenesis (Chemo-angio) treatment groups, prior antibiotic treatment was associated with worse OS (Chemo: 13.8 vs. 17.6 months, p < 0.001; Chemo-angio:11.9 vs. 18.1 months, p = 0.012) and PFS (Chemo: 3.7 vs. 5.8 months, p < 0.001; Chemo-angio: 3.1 vs. 5.9 months, p < 0.001). Cox regression analysis revealed prior antibiotic administration as an independent predictor of OS and PFS (HR for PFS/OS: 1.925/1.452, both p < 0.001). Antibiotic usage duration (HR for PFS/OS: 1.030/1.036, p = 0.009/0.001) and type (PFS/OS: p < 0.001/p = 0.01) also showed significant association with patient prognosis, with calculated interval time cutoff values of 2, 4, and 2 days for fluoroquinolones, β-lactamase inhibitors, and cephalosporins, respectively.

CONCLUSION

Antibiotic use before first-line chemotherapy was associated with poor results in advanced NSCLC patients; treatment length and type being strongly correlated with patient outcomes. Appropriate prolongation of the time between two treatments may enhance patient survival. Further prospective research is however necessary.