Passive Smoking-Induced Mutagenesis as a Promoter of Lung Carcinogenesis.

INTRODUCTION: The International Agency for Research on Cancer has classified passive smoking (PS) or secondhand smoke exposure as a group 1 carcinogen linked to lung cancer. However, in contrast to active smoking, the mutagenic properties of PS remain unclear. METHODS: A consecutive cohort of 564 lung adenocarcinoma samples from female never-smokers, who provided detailed information about their exposure to PS during adolescence and in their thirties through a questionnaire, was prepared. Of these, all 291 cases for whom frozen tumor tissues were available were subjected to whole exome sequencing to estimate tumor mutational burden, and the top 84 cases who were exposed daily, or not, to PS during adolescence, in their thirties or in both periods, were further subjected to whole genome sequencing. RESULTS: A modest yet statistically significant increase in tumor mutational burden was observed in the group exposed to PS compared with the group not exposed to PS (median values = 1.44 versus 1.29 per megabase, respectively; p = 0.020). Instead of inducing driver oncogene mutations, PS-induced substantial subclonal mutations exhibiting APOBEC-type signatures, including SMAD4 and ADGRG6 hotspot mutations. A polymorphic APOBEC3A/3B allele-specific to the Asian population that leads to up-regulated expression of APOBEC3A accentuated the mutational load in individuals exposed daily to PS during adolescence. CONCLUSIONS: This study reveals that PS-induced mutagenesis can promote lung carcinogenesis. The APOBEC3A/3B polymorphism may serve as a biomarker for identifying passive nonsmoking individuals at high risk of developing lung cancer.

Non-specific symptoms as a prodrome of immune-related adverse events in patients with non-small cell lung cancer receiving nivolumab: a consecutive analysis of 200 patients.

PURPOSE: Immune checkpoint blockade therapy is the standard treatment for metastatic or refractory non-small cell lung cancer (NSCLC). However, it is associated with immune-related adverse events (irAEs). irAEs are sometimes fatal; however, an efficient method for early irAEs detection has not been developed because their onset timing varies. We examined the significance of non-specific symptoms as a prodrome of irAEs in patients with NSCLC. METHODS: We reviewed consecutive patients who received nivolumab at a dosage of 3 mg/kg every 2 weeks for metastatic NSCLC between December 2015 and August 2017. Patient demographics, irAEs and signal symptoms were recorded. Non-specific symptoms (fever and fatigue) occurred 7 days or earlier before the onset of irAEs were considered signal symptoms. For statistical analyses, the association between irAEs and clinical information, including signal symptoms, was evaluated using Fisher's exact test and logistic regression. RESULTS: A total of 200 patients received nivolumab; 131 (65.5%) were male, their median age was 63 years (range 30-83), 174 (87.0%) had performance status of 0-1. Signal symptoms occurred in 38 (19.0%) of the 77 patients (38.5%) who experienced irAEs, and were positively associated with the occurrence of irAEs (P < 0.01). Multivariate analysis showed that the occurrence of irAEs was significantly higher in patients with PS 0-1 [odds ratio (OR) 7.01; 95% confidence intervals (CI), 1.69-29.13] and patients experienced signal symptoms (OR 17.30; 95% CI, 6.51-45.99). CONCLUSION: The occurrence of signal symptoms could be used in the early detection and management of irAEs in patients during immune checkpoint blockade therapy.

Safety Implications of Switching Pembrolizumab Dosage From 200 mg Every 3 Weeks to 400 mg Every 6 Weeks in Patients With Advanced NSCLC.

INTRODUCTION: Administration of 400 mg pembrolizumab every 6 weeks (400 mg Q6W) has been approved on the basis of the results of simulated pharmacokinetic modeling and exposure-response analyses. Nevertheless, the safety of switching dosage from 200 mg every 3 weeks (Q3W) to 400 mg Q6W during treatment remains unclear. METHODS: This study involved patients (N = 45) with advanced NSCLC, in whom the pembrolizumab dosage was switched from 200 mg Q3W to 400 mg Q6W between August 2020 and November 2021 in our institute. RESULTS: At the time of switching, the median age of the patients was 71 (range: 32-84) years, and 32 patients (71.1 %) were males. The median number of cycles of 200 mg Q3W before switching was six (range: 1-31). After switching, new or worsening immune-related adverse events (irAEs) occurred in 17 of the 45 patients (37.8%) within three cycles. The irAEs were pneumonitis in 11 patients (24.4%), diarrhea in three patients (6.7%), renal dysfunction in two patients (4.4%), adrenal dysfunction in two patients (4.4%), a skin rash in one patient (2.2%), fulminant type 1 diabetes mellitus in one patient (2.2%). CONCLUSIONS: The switching of pembrolizumab dosage from 200 mg Q3W to 400 mg Q6W resulted in the occurrence of new or worsening irAEs, in particular, pneumonitis, in the early cycles even in patients who had received stable treatment with 200 mg Q3W.