Nicotine promotes brain metastasis by polarizing microglia and suppressing innate immune function.

Up to 40% of lung cancer patients develop brain metastasis, and the median survival of these patients remains less than 6 months. Smoking is associated with lung cancer. However, how smoking impacts the development of brain metastasis remains elusive. We examined 281 lung cancer patients with distant metastasis and found that smokers exhibited a significantly high incidence of brain metastasis. We found that nicotine enhanced brain metastasis, while a depletion of microglia suppressed this effect in vivo. Nicotine skewed the polarity of microglia to the M2 phenotype, thereby increasing the secretion of IGF-1 and CCL20, which promoted tumor progression and stemness. Importantly, nicotine enhanced the expression of SIRPα in microglia and restricted their phagocytic ability. We also identified a compound, parthenolide, that suppressed brain metastasis by blocking M2 polarization. Our results indicate that nicotine promotes brain metastasis by skewing the polarity of M2 microglia, which enhances metastatic tumor growth. Our results also highlight a potential risk of using nicotine for tobacco cessation.

Severe neurologic complications of immune checkpoint inhibitors: a single-center review.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are a promising class of anticancer drugs associated with immune-related adverse events (IRAEs). In registration studies of selected cancer populations, neurologic IRAEs were rare. Post-marketing experience describing their prevalence in clinical practice continues to be reported. METHODS: A retrospective cohort of patients treated at our institution with ICIs from 2005 to 2017 was identified. Patients with new neurologic ICD codes documented during or after ICI treatment were enrolled. Comprehensive medical record review identified patients with neurologic IRAEs causally linked to ICIs. This study focused on CTCAE grade 2-4 IRAEs. RESULTS: 526 patients were screened; 55 candidate patients were identified; 5 cases met criteria for neurologic IRAEs, an incidence of 0.95% (n = 5/526). IRAEs identified were transverse myelopathy, demyelinating sensorimotor polyneuropathy, oculomotor nerve palsy, sensory neuropathy, and posterior reversible encephalopathy syndrome. ICIs were held in three patients, rechallenged in one, and dose-reduced in one. Corticosteroids were given in three patients, and response varied from complete symptom resolution to minimal response and ultimately death. Other treatments were based on IRAE presentation, including gabapentin, antihypertensives, and IV immunoglobulin. Patients with combination therapy appeared to suffer more severe IRAEs producing more substantial long-term morbidity and mortality. CONCLUSION: In this clinical practice study, the incidence of neurologic IRAEs from ICIs was 0.95%. Although rare, neurologic IRAEs can be highly variable and severe, and patients with combination immunotherapy appeared to suffer more severe IRAEs. Neurologists play an important role in the early identification and management of IRAEs to reduce long-term morbidity and mortality.

Hyperglycemia during first-line R-CHOP or dose adjusted R-EPOCH chemotherapy for non-Hodgkin lymphoma is prevalent and associated with chemotherapy alteration - a retrospective study.

High-dose glucocorticoids such as prednisone are combined with cytotoxic chemotherapy in the R-CHOP or dose adjusted R-EPOCH regimens used for non-Hodgkin lymphoma (NHL). In this retrospective study, our primary objective was to evaluate the incidence of hyperglycemia during first-line R-CHOP or DA-EPOCH-R. The secondary objectives were to evaluate the incidence of chemotherapy alteration and overall survival in those with and without hyperglycemia. One hundred and sixty patients were eligible. We found that 47% of all patients had at least one hyperglycemic episode and hyperglycemia was associated with chemotherapy alteration (p = .028). Multivariate analysis revealed international prognostic index (IPI) ≥ 3 (p = .045) and chemotherapy alteration (p = .001) were associated with decreased overall survival. We conclude that hyperglycemia is common during first-line NHL treatment with R-CHOP or DA-EPOCH-R, even in the absence of known diabetes and is associated with alterations of chemotherapy. Baseline pre-PET scan fasting blood glucose of 100 mg/dL or higher may predict hyperglycemia during therapy.