Radiotherapy Is Associated with an Accelerated Risk of Ischemic Stroke in Oral Cavity Cancer Survivors after Primary Surgery

The Risk of Ischemic and Hemorrhagic Stroke in Head and Neck Cancer: A Longitudinal Cohort Study

Several studies have shown that head and neck cancer is associated with an increased risk of stroke incidence. However, investigations of the association between the two diseases based on a matching cohort dataset are still limited. Therefore, we identified the incidence and risk of stroke in patients with head and neck cancer using a nationwide population-based cohort dataset. A total of 5248 individuals without cancer and 1312 with cancer were enrolled from the dataset after a 4:1 propensity score matching. We found that the incidence of overall stroke (per 1000 person years) was 19.29 for those with head and neck cancer, consisting of 17.32 as ischemic type and 2.74 as hemorrhagic type. Additionally, patients with head and neck cancer had a significantly increased risk of overall and ischemic stroke development but not hemorrhagic stroke. Moreover, the risk of stroke development over time was relatively high within the first year after the diagnosis of head and neck cancer. However, in the subgroup analysis, oral cavity cancer survivors showed an increased risk of both ischemic and hemorrhagic strokes. Therefore, our nationwide population-based cohort study suggests that clinicians should closely monitor patients with head and neck cancers for the early detection of stroke.

Risk of critical limb ischemia in long-term uterine cancer survivors: A population-based study

BACKGROUND

The risk of critical limb ischemia (CLI) which causes ischemic pain or ischemic loss in the arteries of the lower extremities in long-term uterine cancer (UC) survivors remains unclear, especially in Asian patients, who are younger at the diagnosis of UC than their Western counterparts.

AIM

To conduct a nationwide population-based study to assess the risk of CLI in UC long-term survivors.

METHODS

UC survivors, defined as those who survived for longer than 5 years after the diagnosis, were identified and matched at a 1:4 ratio with normal controls. Stratified Cox models were used to assess the risk of CLI.

RESULTS

From 2000 to 2005, 1889 UC survivors who received surgery alone or surgery combined with radiotherapy (RT) were classified into younger (onset age < 50 years, n = 894) and older (onset age ≥ 50 years, n = 995) groups. While compared with normal controls, the younger patients with diabetes, hypertension, and receiving hormone replacement therapy (HRT) were more likely to develop CLI. In contrast, the risk of CLI was associated with adjuvant RT, obesity, hypertension, and HRT in the older group. Among the UC survivors, those who were diagnosed at an advanced age (> 65 years, aHR = 2.48, P = 0.011), had hypertension (aHR = 2.18, P = 0.008) or received HRT (aHR = 3.52, P = 0.020) were at a higher risk of CLI.

CONCLUSION

In this nationwide study, we found that the risk factors associated with CLI were similar in both cohorts except for adjuvant RT that was negligible in the younger group, but positive in the older group. Among the survivors, hypertension, advanced age, and HRT were more hazardous than RT. Secondary prevention should include CLI as a late complication in UC survivorship programs.

The Risk of Ischemic Stroke in Head and Neck Cancer Patients and Those Who Were Treated with Radiotherapy: A Population-Based Cohort Study

BACKGROUND

To investigate the standardized incidence ratios (SIR) of stroke in patients with head and neck cancer and their relationship to radiotherapy.

METHODS

Patients with head and neck cancer ages 20-85 years were enrolled from 2007 to 2016 using the Taiwan Cancer Registry. The study endpoint was fatal and non-fatal ischemic stroke, ascertained by the National Health Insurance Research Database. Age- and sex-adjusted SIRs, categorized by 10-year age standardization, were used to compare the patients with head and neck cancer with a randomly selected 2,000,000 general population. We compared the risk of stroke in patients with head and neck cancer who received radiotherapy or surgery alone. Multivariable adjusted hazard ratios (HR) and 95% confidence intervals (CI) were obtained from Cox regression analysis with competing risk.

RESULTS

Among 41,266 patients (mean age, 54.1 years; men, 90.6%) in the median follow-up period of 3.9 years, 1,407 strokes occurred. Compared with the general population, the overall SIR of stroke was 1.37 (95% CI, 1.30-1.44) in patients with head and neck cancer. In patients with head and neck cancer, the fully adjusted HR of stroke in those who received radiotherapy was 0.96 (95% CI, 0.83-1.10), compared with those who received surgery alone.

CONCLUSIONS

Patients with head and neck cancer had a higher risk of fatal or non-fatal ischemic stroke. The risk of stroke was not higher in patients initially treated with radiotherapy.

IMPACT

Oncologists should emphasize stroke prevention in all patients with head and neck cancer, not only in those who received radiotherapy.

MicroRNA-206 relieves irradiation-induced neuroinflammation by regulating connexin 43

Radiation therapy has been widely used for the treatment of various types of cancer; however, it may cause neuroinflammation during the pathological process of the disease. Astrocytes, the most abundant cell type in the central nervous system, have been confirmed to play vital roles in various diseases. Connexin (Cx)43, the main Cx type in astrocytes, which has been identified as a direct target gene of microRNA (miR)-206, was found to be involved in diseases pathologies in regions with astrocytes. The aim of the present study was to investigate the mechanism through which γ-radiation may cause astrocyte neuroinflammation and determine the specific mechanism underlying the effects of miR-206 in irradiation-induced HA-1800 cells. A dual-luciferase reporter system was used to predict and verify the target binding site between Cx43 and miR-206. HA-1800 cell viability and apoptosis were determined using a MTT assay and flow cytometry, respectively. In addition, the HA-1800 cells were induced by γ-radiation, then the protein and mRNA expression levels of Cx43, miR-206 and cleaved-caspase-3 were determined using western blot and reverse transcription-quantitative PCR analyses, respectively. ELISA was also performed to evaluate the concentrations of different inflammatory cytokines (TNF-α, IL-β, IL-6 and IFN-γ). The dual-luciferase reporter system indicated that Cx43 was a direct target of miR-206. miR-206 mimics increased the expression level of miR-206 in the astrocytes. Irradiation suppressed cell proliferation, increased apoptotic cells and enhanced cleaved-caspase-3 expression and inflammatory cytokines secretion in astrocytes. Furthermore, miR-206 was found to be downregulated and its expression was inversely associated with that of Cx43 in γ-radiation-induced astrocytes. Overexpression of miR-206 enhanced miR-206 and suppressed Cx43 expression, while Cx43 was upregulated in HA-1800 cells transfected with miR-206 mimic + Cx43-plasmid. However, the expression level of miR-206 was not significantly different in the Cx43-plasmid transfected group. In addition, it was found that miR-206 mimics relieved irradiation-induced neuroinflammation, which was confirmed by increased cell viability, and reduced cell apoptosis and cleaved caspase-3 protein expression, as well as decreased inflammatory cytokine secretion. Furthermore, all the effects of miR-206 mimics on γ-radiation-induced astrocytes were reversed by Cx43-plasmid. In summary, the results of the present study indicated that miR-206 may relieve irradiation-induced neural damage by regulating Cx43, which may provide a novel research direction and a potential therapeutic target for the clinical treatment of inflammation-associated neuronal injury following irradiation.

Use of Intravenous Thrombolysis in Acute Ischemic Stroke Management in Patients with Active Malignancies: A Topical Review

OBJECTIVES

Our review aims to present existing data on the safety of Intravenous thrombolysis (IVT) use in acute ischemic stroke (AIS) patients with concomitant central nervous system or systemic malignancies, with attention to special circumstances pertaining to specific cancer subtypes to help in acute decision making, especially for neurologists and emergency medicine physicians.

METHODS

A literature search was conducted on electronic databases inclusive of Medline, EMBASE and CINAHL for articles published or available in English between January 1, 2000 to June 1, 2020 using the following search terms: "acute ischemic stroke," "cerebrovascular disease," "Intravenous thrombolysis," "tissue plasminogen activator," "cancer patients," and "neoplasm".

CONCLUSION

Recognition of stroke symptoms in patients with active cancer, in particularly those involving the brain, requires astute clinical judgement. Decision-making can be improved by understanding baseline functional status, cancer prognosis and expected disability from stroke, as well as utilizing diagnostic modalities such acute MRI where needed. While this article does not encourage use of IVT in patients with all malignancies, it lays the groundwork for decision making should thrombolysis be a consideration in a patient with AIS in a cancer patient.