Increase in stroke risk in patients with head and neck cancer: a retrospective cohort study

Carotid Artery Stenosis and Ischemic Stroke in Patients With Head and Neck Cancer Treated With Radiation Therapy: A Critical Review

The purpose of this review is to summarize the literature on carotid artery stenosis (CAS) and ischemic stroke (IS) in patients with head and neck cancer (HNC) treated with radiation therapy (RT) to guide assessment, screening, and management strategies. Patients treated with RT for HNC are at an elevated risk of developing CAS, with published meta-analyses demonstrating that CAS >50% occurs in approximately 25% of patients. Previous research suggests a 10-year cumulative incidence of stroke between 5.7% and 12.5%. Cardiovascular disease (CVD) risk prediction tools such as Qstroke, QRISK-2, and Framingham risk score perform poorly for predicting IS for patients with HNC who received RT. Duplex ultrasound is the most common imaging modality to assess CAS, but controversy remains as to the utility of screening asymptomatic individuals. Only 3 of the 5 major HNC survivorship guidelines acknowledge RT as a risk factor for CAS or IS, while only 1 makes a specific recommendation on screening for CAS (American Head and Neck Society). Within the general population, only 1 CVD guideline discusses RT as a risk factor for CAS (Society for Vascular Surgery). Clinicians involved in the care of patients with HNC treated with RT should be aware of the increased risk of CAS and IS and the challenges in risk prediction. Although there is a lack of evidence to make firm recommendations, HNC survivorship recommendations should ensure HNC survivors and primary care providers are informed of these risks and the importance of assessment and management of CVD risk factors. Future studies are required to refine risk prediction models in patients with HNC and to determine those most likely to benefit from targeted screening and initiation of early preventative strategies.

Vascular events in patients with head and neck cancer: A systematic review and meta-analysis

OBJECTIVE

To assess the incidence of vascular events in patients with head and neck cancer.

REVIEW METHODS

Primary studies identified through April 2023. Meta-analysis was performed.

RESULTS

There were 146 studies included in the systematic review. Rates of events were collected in the overall group, those with chemoprophylaxis, and those that underwent surgery, radiation, or chemotherapy. Of 1 184 160 patients, 4.3% had a vascular event. Radiation therapy had highest risk of overall events and stroke when compared to surgery and chemotherapy. Chemotherapy had a higher risk of stroke and overall events when compared to surgery.

CONCLUSIONS

Vascular events occur in 4%-5% of patients with head and neck cancer. Our data does not support the use of routine anticoagulation. Patients undergoing radiation therapy had the highest frequency of events.

Exploring the Link between Head and Neck Cancer and the Elevated Risk of Acute Myocardial Infarction: A National Population-Based Cohort Study

Enhanced screening protocols for cancer detection have increased survival in patients with head and neck cancer (HNC), which highlights the need to address the sequelae of therapy-induced cardiovascular complications. This study was conducted to assess the incidence and risk of acute myocardial infarction (AMI) in patients with HNC who have not undergone radiation or chemotherapy using a comprehensive, population-based cohort dataset. A total of 2976 individuals without cancer and 744 individuals with HNC were matched using the propensity score method. The findings indicated that the occurrence rates of AMI were comparable between the HNC (2.19) and non-cancer groups (2.39). Cox regression analysis did not demonstrate a significant increase in the risk of AMI in patients with HNC (hazard ratio: 0.93, 95% confidence interval: 0.50-1.73). No increased risk of AMI was observed in the HNC group compared to the non-cancer group, regardless of the time since the HNC diagnosis. Subgroup analyses showed no notable differences in the AMI risk between the groups when considering sex, age, comorbidities, and cancer type. This study showed that patients with HNC who have not been treated with radiation or chemotherapy did not exhibit an increased incidence or risk of AMI compared to individuals without cancer.

Risk of Postoperative Ischemic Stroke and Myocardial Infarction in Patients Operated for Cancer

BACKGROUND

Risk assessment for ischemic stroke (IS) and myocardial infarction (MI) is done routinely before surgery, but the increase in risks associated with surgery is not known. The aim of this study is to assess the risk of arterial ischemic events during the first year after oncological surgery.

METHODS

We used Swedish healthcare databases to identify 443,300 patients who underwent cancer surgery between 1987 and 2016 and 4,127,761 matched comparison subjects. We estimated odds ratios (ORs) for myocardial infarction and ischemic stroke during the hospitalization with logistic regression and calculated 1-year cumulative incidences and hazard ratios (HRs) with 95% confidence intervals (CIs) for the outcomes after discharge.

RESULTS

The cumulative incidences of myocardial infarction and ischemic stroke during the first postoperative year were 1.33% and 1.25%, respectively. In the comparison cohort, the corresponding 1-year cumulative incidences were 1.04% and 1.00%. During the hospitalization, the OR for myocardial infarction was 8.81 (95% CI 8.24-9.42) and the OR for ischemic stroke was 6.71 (95% CI 6.22-7.23). After discharge, the average HR during follow-up for 365 days was 0.90 (95% CI 0.87-0.93) for myocardial infarction and 1.02 (95% CI 0.99-1.05) for ischemic stroke.

CONCLUSIONS

We found an overall increased risk of IS and MI during the first year after cancer surgery that was attributable to events occurring during the hospitalization period. After discharge from the hospital, the overall risk of myocardial infarction was lower among the cancer surgery patients than among matched comparison subjects.

Stroke Risk in Survivors of Head and Neck Cancer

Importance

Survivors of head and neck cancers (HNC) have increased risk of stroke. A comprehensive report using standardized methods is warranted to characterize the risk and to inform on survivorship strategy.

Objective

To determine the stroke risk in subpopulations of survivors of HNC in Singapore.

Design, Setting, and Participants

This national, registry-based, cross-sectional study aimed to estimate stroke risk in subgroups of the HNC population between January 2005 and December 2020. Participants were identified from the Singapore Cancer Registry, the Singapore Stroke Registry, and the Registry of Birth and Deaths using relevant International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification (ICD-10-AM) codes. HNC subgroups were defined based on patient demographic, disease, and treatment factors. Data were analyzed from September 2022 to September 2023.

Exposure

Diagnosis of HNC.

Main Outcomes and Measures

Both ischemic and hemorrhagic stroke were studied. The age-standardized incidence rate ratio (SIRR) and age-standardized incidence rate difference (SIRD) were reported. The Singapore general population (approximately 4 million) served as the reference group for these estimations.

Results

A total of 9803 survivors of HNC (median [IQR] age at diagnosis, 58 [49-68] years; 7166 [73.1%] male) were identified. The most common HNC subsites were nasopharynx (4680 individuals [47.7%]), larynx (1228 individuals [12.5%]), and tongue (1059 individuals [10.8%]). A total of 337 individuals (3.4%) developed stroke over a median (IQR) follow-up of 42.5 (15.0-94.5) months. The overall SIRR was 2.46 (95% CI, 2.21-2.74), and the overall SIRD was 4.11 (95% CI, 3.37-4.85) strokes per 1000 person-years (PY). The cumulative incidence of stroke was 3% at 5 years and 7% at 10 years after HNC diagnosis. The SIRR was highest among individuals diagnosed at younger than 40 years (SIRR, 30.55 [95% CI, 16.24-52.35]). All population subsets defined by age, sex, race and ethnicity, HNC subsites (except tongue), stage, histology, and treatment modalities had increased risk of stroke compared with the general population. The SIRR and SIRD were significantly higher among individuals who had a primary radiation treatment approach (SIRR, 3.01 [95% CI, 2.64-3.43]; SIRD, 5.12 [95% CI, 4.18-6.29] strokes per 1000 PY) compared with a primary surgery approach (SIRR, 1.64 [95% CI, 1.31-2.05]; SIRD, 1.84 [95% CI, 0.923.67] strokes per 1000 PY).

Conclusions and Relevance

In this cross-sectional study of survivors of HNC, elevated stroke risks were observed across different age, subsites, and treatment modalities, underscoring the importance of early screening and intervention.

Late-onset vascular complications of radiotherapy for primary brain tumors: a case-control and cross-sectional analysis

PURPOSE

Radiotherapy (RT) is a recognized risk factor for cerebrovascular (CV) disease in children and in adults with head and neck cancer. We aimed to investigate whether cerebral RT increases the risk of CV disease in adults with primary brain tumors (PBT).

METHODS

We retrospectively identified adults with a supratentorial PBT diagnosed between 1975 and 2006 and with at least 10 years follow-up after treatment. We analyzed demographic, clinical, and radiological features with special attention to CV events. We also described CV events, vascular risk factors, and intracranial artery modifications in a cross-sectional study of irradiated patients alive at the time of the study.

RESULTS

A total of 116 patients, treated with RT (exposed group), and 85 non-irradiated patients (unexposed group) were enrolled. Stroke was more frequent in irradiated PBT patients than in the unexposed group (42/116 (36%) vs 7/85 (8%); p < 0.001), with higher prevalence of both ischemic (27/116 (23%) vs 6/85 (7%); p = 0.004) and hemorrhagic (12/116 (10%) vs 1/85 (1%); p = 0.02) stroke. In the irradiated group, patients with tumors near the Willis Polygon were more likely to experience stroke (p < 0.016). Fourty-four alive irradiated patients were included in the cross-sectional study. In this subgroup, intracranial arterial stenosis was more prevalent (11/45, 24%) compared to general population (9%).

CONCLUSIONS

Stroke prevalence is increased in long-surviving PBT patients treated with cranial RT.

IMPLICATIONS FOR CANCER SURVIVORS

CV events are frequent in long survivors of PBT treated with cerebral RT. We propose a check list to guide management of late CV complications in adults treated with RT for PBT.

Previous Ischemic Stroke Significantly Alters Stroke Risk in Newly Diagnosed Cancer Patients

BACKGROUND

Previous ischemic stroke (IS) is a risk factor for subsequent IS in the general population; it is unclear if this relationship remains true in patients with cancer. Our objective was to examine the association between previous IS and risk for future IS in individuals newly diagnosed with cancer.

METHODS

We conducted a retrospective population-based matched cohort study of newly diagnosed adult cancer patients (excluding nonmelanoma skin cancers and primary central nervous system tumors) in Ontario, Canada from 2010 to 2020; those with prior IS were matched (1:4) by age, sex, year of cancer diagnosis, cancer stage, and cancer site to those without a history of stroke. Cumulative incidence function curves were created to estimate the incidence of IS. Subdistribution adjusted hazard ratios (aHRs) and 95% CIs were calculated, where death was treated as a competing event. Multivariable analysis was adjusted for imbalanced baseline characteristics.

RESULTS

We examined 65 525 individuals with cancer, including 13 070 with a history of IS. The median follow-up duration was 743 days (interquartile range, 177-1729 days). The incidence of IS following cancer diagnosis was 261.3/10 000 person-years in the cohort with prior IS and 75.3/10 000 person-years in those without prior IS. Individuals with prior IS had an increased risk for IS after cancer diagnosis compared with those without a history (aHR, 2.68 [95% CI, 2.41-2.98]); they also had more prevalent cardiovascular risk factors. The highest risk for stroke compared with those without a history of IS was observed in the gynecologic cancer (aHR, 3.84 [95% CI, 2.15-6.85]) and lung cancer (aHR, 3.18 [95% CI, 2.52-4.02]) subgroups. The risk of IS was inversely correlated with lag time of previous stroke; those with IS 1 year before their cancer diagnosis had the highest risk (aHR, 3.68 [95% CI, 3.22-4.22]).

CONCLUSIONS

Among individuals with newly diagnosed cancer, those with IS history were almost 3× more likely to experience a stroke after cancer diagnosis, especially if the prediagnosis stroke occurred within 1 year preceding cancer diagnosis.

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.

Mechanisms by which statins protect endothelial cells from radiation-induced injury in the carotid artery

Background

The incidental use of statins during radiation therapy has been associated with a reduced long-term risk of developing atherosclerotic cardiovascular disease. However, the mechanisms by which statins protect the vasculature from irradiation injury remain poorly understood.

Objectives

Identify the mechanisms by which the hydrophilic and lipophilic statins pravastatin and atorvastatin preserve endothelial function after irradiation.

Methods

Cultured human coronary and umbilical vein endothelial cells irradiated with 4 Gy and mice subjected to 12 Gy head-and-neck irradiation were pretreated with statins and tested for endothelial dysfunction, nitric oxide production, oxidative stress, and various mitochondrial phenotypes at 24 and 240 h after irradiation.

Results

Both pravastatin (hydrophilic) and atorvastatin (lipophilic) were sufficient to prevent the loss of endothelium-dependent relaxation of arteries after head-and-neck irradiation, preserve the production of nitric oxide by endothelial cells, and suppress the cytosolic reactive oxidative stress associated with irradiation. However, only pravastatin inhibited irradiation-induced production of mitochondrial superoxide; damage to the mitochondrial DNA; loss of electron transport chain activity; and expression of inflammatory markers.

Conclusions

Our findings reveal some mechanistic underpinnings of the vasoprotective effects of statins after irradiation. Whereas both pravastatin and atorvastatin can shield from endothelial dysfunction after irradiation, pravastatin additionally suppresses mitochondrial injury and inflammatory responses involving mitochondria. Clinical follow-up studies will be necessary to determine whether hydrophilic statins are more effective than their lipophilic counterparts in reducing the risk of cardiovascular disease in patients undergoing radiation therapy.

Stroke death in patients receiving radiation for head and neck cancer in the modern era

Objectives

Head and neck cancer is a common malignancy frequently treated with chemotherapy and radiotherapy. Studies have shown an increased risk of stroke with the receipt of radiotherapy, but data on stroke-related mortality are limited, particularly in the modern era. Evaluating stroke mortality related to radiotherapy is vital given the curative nature of head and neck cancer treatment and the need to understand the risk of severe stroke in this population.

Methods

We analyzed the risk of stroke death among 122,362 patients (83,651 patients who received radiation and 38,711 patients who did not) with squamous cell carcinoma of the head and neck (HNSCC) diagnosed between 1973 and 2015 in the SEER database. Patients in radiation vs. no radiation groups were matched using propensity scores. Our primary hypothesis was that radiotherapy would increase the hazard of death from stroke. We also examined other factors impacting the hazard of stroke death, including whether radiotherapy was performed during the modern era when IMRT and modern stroke care were available as well as increased HPV-mediated cancers of the head and neck. We hypothesized that the hazard of stroke death would be less in the modern era.

Results

There was an increased hazard of stroke-related death in the group receiving radiation therapy (HR 1.203, p = 0.006); however, this was a very small absolute increase, and the cumulative incidence function of stroke death was significantly reduced in the modern era (p < 0.001), cohorts with chemotherapy (p=0.003), males (p=0.002), younger cohorts (p<0.001) and subsites other than nasopharynx (p=0.025).

Conclusions

While radiotherapy for head and neck cancer increases the hazard of stroke death, this is reduced in the modern era and remains a very small absolute risk.

Is stroke incidence increased in survivors of adult cancers? A systematic review and meta-analysis

PURPOSE

Existing research hints that people living with and beyond cancer are at an increased risk of stroke. However, there is insufficient evidence to appropriately inform guidelines for specific stroke prevention or management for cancer patients. We conducted a systematic review and meta-analysis to describe and quantify stroke incidence in people living with and beyond cancer.

METHODS

Medline, CINAHL, and EMBASE were searched for epidemiological studies comparing stroke incidence between cancer and non-cancer patients. Reviewers independently extracted data; random-effects meta-analyses and quality assessment were performed.

RESULTS

Thirty-six studies were narratively synthesised. Meta-analysis was conducted using seven studies. Methodological quality was high for most studies. Study populations were heterogeneous, and the length of follow-up and risk factors varied. There was a variation in risk between different cancer types and according to stroke type: pancreatic (HR 2.85 (95% CI 2.43-3.36), ischaemic) (HR 2.28 (95% CI 1.43-3.63), haemorrhagic); lung (HR 2.33 (95% CI 1.63-3.35), ischaemic) (HR 2.14 (95% CI 1.45-3.15), haemorrhagic); and head and neck (HR 1.54 (95% CI 1.40-1.69), haemorrhagic) cancers were associated with significantly increased incidence of stroke. Risk is highest within the first 6 months of diagnosis. Narrative synthesis indicated that several studies also showed significantly increased incidence of stroke in individuals with colorectal cancer, breast cancer, ovarian cancer, nasopharyngeal cancer, leukaemia, and myeloma, and those who have received radiotherapy for head and neck cancers and platinum-based chemotherapy may also have higher stroke incidence.

CONCLUSIONS

Stroke incidence is significantly increased after diagnosis of certain cancers.

IMPLICATIONS FOR CANCER SURVIVORS

Cardiovascular risk should be assessed during cancer survivorship care, with attention to modifying shared cancer/cardiovascular risk factors.

Risk of cardiovascular diseases in cancer patients: A nationwide representative cohort study in Taiwan

BACKGROUND

The associations with cancer and cardiovascular diseases (CVD) had inconsistent results. The study aimed to investigate the risk of cardiovascular diseases (CVD) between populations with and without cancer.

METHODS

Patients with common cancers in Taiwan were enrolled in the study between 2007 and 2018 using the Taiwan Cancer Registry. We focused on colorectal cancer, women's breast cancer, lung cancer, liver cancer, oral cancer, prostate cancer, and thyroid cancers. The study endpoint was fatal and non-fatal CVD, which was defined as ischemic heart disease and ischemic stroke according to the National Health Insurance Research Database. We compared the risk of CVD between patients with cancer and age- and sex-matched (1:1 ratio) participants who did not have cancer or CVD. Multivariable adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were obtained from Cox regression analysis. To evaluate the chronological trend, we estimated the HRs and 95% CI yearly since the diagnosis.

RESULTS

Among the 552,485 cancer patients (mean age, 60.6 years; women, 47.7%) during the median follow-up period of 4.1 years, 32,634 cases of fatal and non-fatal CVD were identified. Compared with that noted in the non-cancer population, the overall fully adjusted HR with 95% CI was 1.28 (1.25, 1.30) in the cancer population. The CVD risk was the highest in the first year, the adjusted HR with 95% CI was 2.31 (2.23, 2.40), and this risk decreased yearly.

CONCLUSIONS

Patients with cancer had a significantly higher risk of fatal or non-fatal CVD. The risk was the highest in the first year since diagnosis and decreased yearly.

Risk for Arterial Thromboembolic Events (ATEs) in Patients with Advanced Urinary Tract Cancer (aUTC) Treated with First-Line Chemotherapy: Single-Center, Observational Study

Arterial thromboembolism has been associated with cancer or its treatment. Unlike venous thromboembolism, the incidence and risk factors have not been extensively studied. Here, we investigated the incidence of arterial thromboembolic events (ATEs) in an institutional series of advanced urinary tract cancer (aUTC) treated with cytotoxic chemotherapy. The ATE definition included peripheral arterial embolism/thrombosis, ischemic stroke and coronary events. A total of 354 aUTC patients were analyzed. Most patients (95.2%) received platinum-based chemotherapy. A total of 12 patients (3.4%) suffered an ATE within a median time of 3.6 months from the start of chemotherapy. The most frequent ATE was ischemic stroke (n = 7). Two ATEs were fatal. The 6-month and 24-month incidence were 2.1% (95% confidence interval [CI]: 0.9-4.1) and 3.6% (95% CI: 1.9-6.2), respectively. Perioperative chemotherapy increased the risk for ATE by 5.55-fold. Tumors other than UTC and pure non-transitional cell carcinoma histology were also independent risk factors. No association with the type of chemotherapy was found. Overall, ATEs occur in 4.6% of aUTC patients treated with chemotherapy and represent a clinically relevant manifestation. Perioperative chemotherapy significantly increases the risk for ATE. The role of prophylaxis in high-risk groups should be prospectively studied.

Association Between Up-front Surgery and Risk of Stroke in US Veterans With Oropharyngeal Carcinoma

Importance

Cardiovascular events are an important cause of morbidity in patients with oropharyngeal squamous cell carcinoma (OPSCC). Radiation and chemotherapy have been associated with increased risk of stroke; up-front surgery allows the opportunity for (chemo)radiotherapy de-escalation.

Objective

To evaluate whether up-front surgery was associated with decreased stroke risk compared to nonsurgical treatment for OPSCC.

Design, Setting, and Participants

This cohort study was conducted at the US Veterans Health Administration and examined US veterans diagnosed with nonmetastatic OPSCC from 2000 to 2020. Data cutoff was September 17, 2021, and data analysis was performed from October 2021 to February 2022.

Exposures

Up-front surgical treatment or definitive (chemo)radiotherapy as captured in cancer registry.

Main Outcomes and Measures

Cumulative incidence of stroke, accounting for death as a competing risk; and association between up-front surgery and stroke risk. After generating propensity scores for the probability of receiving surgical treatment and using inverse probability weighting (IPW) to construct balanced pseudo-populations, Cox regression was used to estimate a cause-specific hazard ratio (csHR) of stroke associated with surgical vs nonsurgical treatment.

Results

Of 10 436 patients, median (IQR) age was 61 (56-67) years; 10 329 (99%) were male; 1319 (13%) were Black, and 7823 (75%) were White; 2717 received up-front surgery, and 7719 received nonsurgical therapy with definitive (chemo)radiotherapy. The 10-year cumulative incidence of stroke was 12.5% (95% CI, 11.8%-13.3%) and death was 57.3% (95% CI, 56.2%-58.4%). Surgical patients who also received (chemo)radiotherapy had shorter radiation and chemotherapy courses than nonsurgical patients. After propensity score and IPW, the csHR of stroke for surgical treatment was 0.77 (95% CI, 0.66-0.91). This association was consistent across subgroups defined by age and baseline cardiovascular risk factors.

Conclusions and Relevance

In this cohort study, up-front surgical treatment was associated with a 23% reduced risk of stroke compared with definitive (chemo)radiotherapy. These findings present an important additional risk-benefit consideration to factor into treatment decisions and patient counseling and should motivate future studies to examine cardiovascular events in this high-risk population.

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.

The risk of cardiovascular disease and stroke in survivors of head and neck cancer in Korea

BACKGROUND

Head and neck cancer (HNCA) survivors have a high risk of developing cardiovascular disease (CVD) or stroke because of sharing risk factors of disease. Therefore, we investigated the risk of CVD or stroke occurrence among HNCA survivors in Korea based on the Health Insurance Review and Assessment (HIRA) Service claims database.

METHODS

We retrieved claims data of patients who were diagnosed with HNCA in 2014-2015 using ICD-10 code and followed up data until 2018. Patients with newly diagnosed with CVD or stroke after HNCA diagnosis during the follow-up period were detected. We analyzed the characteristics of patients with HNCA who were subsequently diagnosed with CVD or stroke. In addition, the risk factors of CVD or stroke occurrence were investigated using Cox proportional hazard regression analysis.

RESULTS

Among the 8288 patients with HNCA, 477 and 404 patients were diagnosed with new-onset CVD and stroke, respectively. Patients with hypertension, diabetes mellitus (DM), and hyperlipidemia had a 3.25-fold higher risk of CVD comparing to patients without any underlying disease (95% confidence index [CI], 2.38-4.45) Patients with three underlying diseases had a 2.92-fold higher risk of stroke compared to patients without any underlying disease (95% CI 2.03-4.21).

CONCLUSIONS

HNCA survivors with hypertension, DM, and hyperlipidemia should be cautious of the risks of CVD and stroke.

Risk of Stroke in Nasopharyngeal Cancer Survivors: A National Registry-Based Population Cohort Study

BackgroundWe aim to determine the risk of stroke and death within 30 days post stroke in nasopharyngeal cancer (NPC) survivors.MethodsWe conducted a population-based cohort study of patients diagnosed with NPC from Jan 1, 2005 to Dec 31, 2017. Using the cancer and stroke disease registries and the Singapore general population as the reference population, we report the age-standardized incidence rate differences (SIRDs) ratios (SIRs) and the cumulative incidence of stroke and the standardized mortality rate differences (SMRDs) and ratios (SMRs) for all causes of death within 30 days post stroke for NPC survivors.FindingsAt a median follow up of 48.4 months (IQR 19.8 - 92.9) for 3849 patients diagnosed with NPC, 96 patients developed stroke. The overall SIRD and SIR for stroke was 3.12 (95% CI 2.09 - 4.15) and 2.54 (95% CI 2.08 - 3.10) respectively. The SIRD was highest for the age group 70 - 79 years old (8.84 cases per 1000 person-years (PY); 0.46 - 17.21) while the SIR was highest for the age group 30 - 39 years old (16.41; 6.01 - 35.82). The SIRD and SIR for stage 1 disease was (6.96 cases per 1000 PY; 2.16 - 11.77) and (4.15; 2.46 - 7.00) respectively. The SMRD and SMR for all cause deaths within 30 days of stroke was (3.20 cases per 100 persons; -3.87 - 10.28) and (1.34; 0.76 - 2.37) respectively.InterpretationThe overall risk of stroke was markedly elevated in survivors of NPC, especially in Stage 1 disease when compared to the general population. The risk of death within 30 days of stroke was not significantly higher for NPC survivors.Classification of EvidenceThis study provides Class II evidence of the increased risk of stroke in survivors of nasopharyngeal cancer compared to general population.

Risk Factors of Arterial Events in Patients with Venous Thromboembolism: A Systematic Review and Meta-Analysis

BACKGROUND

 If recent studies suggested that arterial ischemic events in patients with venous thromboembolism (VTE) are more frequent than in the general population without VTE, whether patients with VTE have different risk factors of arterial events than classic known cardiovascular risk factors remain undefined. Through this systematic review and meta-analysis, we aimed to identify risk factors of arterial ischemic events in patients with VTE.

METHODS

 We searched PubMed, EMBASE, and Cochrane databases to identify cohort studies published between January 1, 2000, and December 31, 2020, reporting risk factors of arterials ischemic events in patients with VTE. Random-effect models meta-analysis served to get the pooled hazard ratio (HR) and 95% confidence interval (CI) of each risk factor identified.

RESULTS

 We screened 1,467 records of which 18 were finally included in systematic review and 10 in meta-analyses. Adjusted HR for 9 factors were included in meta-analysis. Male gender (HR: 1.38; 95% CI: 1.28-1.49), diabetes (HR: 1.65; 95% CI: 1.28-2.12), hypertension (HR: 1.38; 95% CI: 1.04-1.84), previous atherothrombotic event (HR: 3.22; 95% CI: 1.12-9.23), chronic kidney disease (HR: 1.41; 95% CI: 1.05-1.88), cancer (HR: 1.72; 95% CI: 1.41-2.09), and unprovoked VTE (HR: 1.88; 95% CI: 1.37-2.57) were the identified risk factors of arterial events in VTE population after meta-analysis.

CONCLUSION

 Risk factors of arterial events in patients with VTE include usual cardiovascular risk factors and other risk factors that are related to VTE such as cancer and unprovoked VTE.

Risk of stroke in cancer survivors using a propensity score-matched cohort analysis

Little is known about the risk of cerebrovascular disease in cancer survivors. We aimed to assess the association between incident cancer and the subsequent risk of stroke using a large-scale, population-based prospective study. 74,530 Japanese aged between 40 and 69 years at baseline study were matched by the status of cancer diagnosis during follow-up using propensity score nearest-neighbor matching with allowance for replacement. A total of 2242 strokes were reported during 557,885 person-years of follow-up. Associations between incident cancer and the subsequent risk of all strokes, cerebral infarction, and intracerebral hemorrhage were assessed using a Cox proportional hazards model stratified on the propensity score-matched pairs. No significant association was observed between the status of cancer diagnosis of all types, gastric, colorectal and lung cancer, and subsequent occurrence of all strokes, cerebral infarction, and intracerebral hemorrhage. However, analysis by discrete time periods suggested an elevated risk in cancer patients for one to three months after a cancer diagnosis in all stroke (HR, 2.24; 95% CI, 1.06, 4.74) and cerebral infarction (HR, 2.62; 95% CI, 1.05, 6.53). This prospective cohort study found no association between the status of cancer diagnosis and the subsequent occurrence of all strokes and its subtypes during the entire follow-up period but suggested an increase in stroke risk during the active phase of malignancy.

Incidence and Risk of Various Types of Arterial Thromboembolism in Patients With Cancer

OBJECTIVE

To describe the temporal association and identify risk factors between cancer diagnosis and various types of arterial thromboembolism (ATE).

PATIENTS AND METHODS

We inquired an aggregated electronic health record database (Explorys, IBM Corp., Armonk, New York) and identified patients with cancer from January 1999 to October 2019, with various types of ATE, including myocardial infarction, acute ischemic stroke, acute limb ischemia, acute mesenteric ischemia, acute renal infarction, and retinal artery occlusion. We investigated the temporal relationship between cancer diagnosis and ATE events by examining the incidence ratio (IR) of ATE before and after diagnosis of cancer.

RESULTS

We identified 305,384 patients with cancer and ATE. The 30-day interval IR of total ATE was elevated shortly before and after cancer diagnosis, which was consistent among different ATE and cancer types. The incidence was highest within a 330-day window (90 days before and 240 days after cancer diagnosis), and IR peaked at 13.9 (95% confidence interval [CI], 13.6 to 14.2) in the first 30 days following diagnosis of cancer. Compared with patients with cancer who never developed ATE, patients with ATE had more cardiovascular risk factors at baseline. Patients with brain cancer, lung cancer, colorectal cancer, and pancreatic cancer had the highest risk of developing ATE, whereas ATE type was anatomically associated with cancer type.

CONCLUSION

In this observational study of an aggregated US patient population, those with newly diagnosed cancer had increased risk of ATE events. This risk was most elevated in a 330-day window around cancer diagnosis and was consistent across different types of ATE and cancer.

The incidence of myocardial infarction and stroke in head and neck cancer patients

Various treatment modalities are used for head and neck cancer (HNC). This study analyzed the incidence and risks of myocardial infarction (MI) and stroke by cancer site and treatment modality in 22,737 patients newly diagnosed with HNC registered in the Korean National Health Insurance Service database in 2007–2013. An additional 68,211 patients without HNC, stroke, or MI were identified as the control group. The risks for MI (hazard ratio [HR] = 1.38, 95% confidence interval [CI] 1.24–1.53), stroke (HR = 1.48, 95% CI 1.37–1.60), and mortality (HR = 5.30, 95% CI 5.14–5.47) were significantly higher in the HNC group. Analysis by cancer site showed the risk of MI and mortality was highest in hypopharynx cancer, while the risk of stroke was highest in nasopharynx and paranasal sinus cancer. Analysis by treatment modality showed the highest risks for MI (HR = 1.88, 95% CI 1.31–2.69) and mortality (HR = 2.95, 95% CI 2.75–3.17) in HNC patients receiving chemotherapy (CT) alone, while HNC patients receiving CT with surgery had the highest risk for stroke (HR = 1.81, 95% CI 1.14–2.88). Careful attention to MI and stroke risks in HNC patients is suggested, especially those who received both CT and radiotherapy.

Risk of Stroke in Cancer Survivors: A Meta-analysis of Population-Based Cohort Studies

OBJECTIVE

Accumulating evidence suggests that cancer survivors may have a relatively higher risk of stroke. The aim of this meta-analysis was to determine whether cancer survivors have a relatively higher risk of stroke than cancer-free populations on the basis of published data from population-based cohort studies.

METHODS

PubMed, Embase, and Cochrane Library were searched from inception to February 8, 2020, for population-based cohort studies. Effect estimates with 95% confidence intervals (CIs) were pooled using the random-effects model. We conducted subgroup analyses and meta-regression to explore sources of heterogeneity and the stability of the results.

RESULTS

Twenty population-based cohort studies involving 10,479,530 participants were identified. Overall, the relative risk (RR) for stroke in cancer survivors was 1.66 (95% CI 1.35-2.04; p < 0.001) compared with that in cancer-free controls; survivors of head and neck, hematologic, lung, pancreas, and stomach cancer (all p < 0.05) showed consistently significant results, whereas no significant increased risk was observed for patients with other cancer types. The effects were more prominent in cancer survivors with female sex (RR 1.38, 95% CI 1.18-1.61; p < 0.001), younger age at cancer diagnosis (<45 years) (RR 2.57, 95% CI 1.27-5.19; p = 0.009), and shorter cancer survival duration (≥1-2 years) (RR 1.69, 95% CI 1.18-2.42; p = 0.004). Moreover, cancer survivors had a significantly increased risk of ischemic stroke (RR 1.53, 95% CI 1.28-1.84; p < 0.001) compared with hemorrhagic stroke.

CONCLUSIONS

Cancer plays a critical role in the etiologic of stroke. Due to the existence of substantial heterogeneity among the included studies, the results should be interpreted with caution. However, early prevention and effective intervention of stroke in cancer survivors require attention from health policy makers.

Real-world data: towards achieving the achievable in cancer care

The use of data from the real world to address clinical and policy-relevant questions that cannot be answered using data from clinical trials is garnering increased interest. Indeed, data from cancer registries and linked treatment records can provide unique insights into patients, treatments and outcomes in routine oncology practice. In this Review, we explore the quality of real-world data (RWD), provide a framework for the use of RWD and draw attention to the methodological pitfalls inherent to using RWD in studies of comparative effectiveness. Randomized controlled trials and RWD remain complementary forms of medical evidence; studies using RWD should not be used as substitutes for clinical trials. The comparison of outcomes between nonrandomized groups of patients who have received different treatments in routine practice remains problematic. Accordingly, comparative effectiveness studies need to be designed and interpreted very carefully. With due diligence, RWD can be used to identify and close gaps in health care, offering the potential for short-term improvement in health-care systems by enabling them to achieve the achievable.

Stroke Rate Increases Around the Time of Cancer Diagnosis

Objective: To test whether strokes increase around the time of cancer diagnosis, we comprehensively examined the correlations of cancer and stroke by employing a population-based cohort study design. Methods: One million people insured under the Taiwan's National Health Insurance program in 2005 were randomly sampled to create the study's dataset. According to the presence of cancer and/or stroke, patients were separated into cancer and stroke, cancer-only, and stroke-only groups. Diagnoses of cancer, stroke, and comorbidities were defined according to ICD9-CM codes. Cancer and non-cancer populations were matched by age at cancer diagnosis, gender, and stroke risk factors, and each patient with cancer was matched with two non-cancer controls nested in the same year of cancer diagnosis. The hazards of stroke and cumulative incidences within a year after cancer diagnosis were evaluated using Fine and Gray's subdistributional hazard model. Results: The temporal distribution of first-ever stroke in patients with both cancer and stroke was a sharpened bell shape that peaked between 0.5 years before and after cancer diagnosis. Frequencies of stroke were further adjusted by number of cancer survivors. The monthly event rate of stroke remained nested around the time of cancer diagnosis in all strokes. Brain malignancies, lung cancer, gastric cancer, prostate cancer, and leukemia patients obtained higher ratio of stroke, while breast cancer and thyroid cancer patients had low percentage of combining stroke. When compared to non-cancer matched control, the hazard of stroke within one year after cancer diagnosis was increased by cancer at a subdistributional hazard ratio of 1.72 (95% confident interval 1.48 to 2.01; p < 0.0001). Conclusions: Cancer increased the risk of stroke and stroke events were nested around the time of cancer diagnosis, occurring 0.5 years prior to cancer on average regardless of stroke type.

Trousseau syndrome in a patient with advanced oral squamous cell carcinoma: a case report

Background

Trousseau syndrome is known as a variant of cancer-associated thrombosis. Trousseau syndrome commonly occurs in patients with lung or prostate cancer. Hypercoagulability is thought to be initiated by mucins produced by the adenocarcinoma, which react with leukocyte and platelet selectins to form platelet-rich microthrombi. This is the first report of Trousseau syndrome in a patient with oral cancer.

Case presentation

Here, we describe the case of a 61-year-old Japanese man diagnosed as having advanced buccal carcinoma (T4bN2bM1; the right scapula, erector spinae muscles, and the right femur), who experienced aphasia and loss of consciousness. Although magnetic resonance imaging showed cerebral infarction, carotid invasion by the tumor and carotid sheath rupturing, cardiovascular problems, and bacterial infection were not present, which indicated Trousseau syndrome.

Conclusions

Trousseau syndrome in oral cancer is rare, but we must always consider cancer-associated thrombosis in patients with advanced stages of cancer regardless of the primary site of the cancer and take steps to prevent it.

Documentation and incidence of late effects and screening recommendations for adolescent and young adult head and neck cancer survivors treated with radiotherapy

PURPOSE

A retrospective review of adolescent and young adult (AYA) head and neck cancer (HNC) patients treated with radiation therapy (RT) at British Columbia Cancer  was performed to determine the incidence of late toxicities, the documented late side effects discussed and the screening recommendations provided at the time of transfer of care to primary care providers (PCPs).

METHODS

Charts (n = 162) were reviewed for all patients 15 to 35 years at diagnosis with HNC treated with RT from 1960 to 2010 who survived > 5 years after diagnosis.

RESULTS

A discussion regarding the risk of long-term side effects was documented in the initial consultation for 85% of patients. The majority of patients (78%) developed > 1 documented late effect. The most common were xerostomia (44%), skin changes (28%), neck fibrosis (22%), nasal crusting (16%), epistaxis (16%), and dental decay (14%). In all, 20% were currently followed or were followed until they died. Of the 80% transferred to their PCP, 14% had a formal discharge summary. For those discharged from British Columbia Cancer, documented recommendations included regular dental care (34%) and screening for hypothyroidism (5%) and second malignancy (4%).

CONCLUSIONS

The majority of AYA HNC patients treated with RT developed late side effects, and most PCPs were not sent a discharge summary outlining screening recommendations for delayed late effects.

IMPLICATIONS FOR CANCER SURVIVORS

AYA HNC survivors treated with RT are at high risk for late effects and would benefit from a survivorship care plan outlining these risks and screening recommendations.

Cancer and Thrombosis-New Insights

Cancer patients have a pro-thrombotic state attributed to the ability of cancer cells to activate the coagulation system and interact with hemostatic cells, thus tilting the balance between pro- and anticoagulants. Mechanisms underlying the coagulation system activation involve tumor cells, endothelial cells, platelets, and white blood cells. Anti-cancer therapies, including anti-angiogenic drugs, significantly increase the risk of thrombosis during treatment. Along with the role of coagulation proteins in the hemostatic system, these proteins also serve as growth factors to the tumor. Heparanase is a pro-angiogenic and pro-metastatic protein. Our previous studies have demonstrated that it enhances tissue factor (TF) activity and is present at high levels in tumor cells and patients' blood. Strategies to attenuate heparanase effects by heparin mimetics or peptides interrupting the TF-heparanase interaction are good candidates to attenuate tumor growth and thrombotic manifestations.

Arterial Ischemic Events Are a Major Complication in Cancer Patients with Venous Thromboembolism

BACKGROUND

Venous thromboembolism is common in patients with malignancies, affecting up to 10% of this patient population. The association between arterial ischemic events and venous thromboembolism also has been established. However, the influence of arterial ischemic events on outcomes in cancer patients with venous thromboembolism has not been fully determined.

METHODS

The current study analyzed clinical characteristics, time course, risk factors, incidence and severity of venous thromboembolism recurrences, arterial ischemic events and major bleeding in 5717 patients with active cancer and venous thromboembolism recruited into RIETE (multi-center prospective registry of patients with objectively confirmed venous thromboembolism).

RESULTS

During the anticoagulation course (median 7.3 months), 499 (8.7%) patients developed venous thromboembolism recurrences, 63 (1.1%) developed arterial events, and 346 (6.1%) suffered from major bleeding. Overall, major bleeding and arterial events appeared earlier (median 35 and 36 days, respectively) than venous thromboembolism recurrences (median 97 days). Thirty-day mortality rates after each event were: 20% after recurrent pulmonary embolism, 13% after recurrent deep vein thrombosis, 41% after major bleeding, 40% after myocardial infarction, 64% after ischemic stroke, and 83% after lower limb amputation. Bleeding was the leading cause of death (67 fatal bleeds), whereas cumulative mortality due to arterial ischemic events (n = 27) was similar to that related to pulmonary embolism recurrences (n = 26).

CONCLUSIONS

In this study, arterial ischemic events and major bleeding appeared early after venous thromboembolism in patients with active cancer and were among frequent causes of their deaths. The risk and severity of arterial events need to be considered in this clinical setting.

Neck dissection does not increases the risk of stroke in thyroid cancer: A national cohort study

Objectives

The purpose of this study is to evaluate the risk of stroke (hemorrhagic or ischemic) after neck dissection in thyroid cancer patients in Korea using national cohort data.

Methods

Using the national cohort study from the Korean Health Insurance Review and Assessment Service, patients with neck dissection for thyroid cancer (1,041) and control participants (4,164) were selected and matched 1:4 (age, gender, income, and region of residence). The Chi-square test, Fischer’s exact test, and the Cox-proportional hazard model were used. The Cox-proportional analysis used a crude model and an adjusted model for age, gender, income, region of residence, hypertension, diabetes, dyslipidemia.

Results

None of the participants had suffered hemorrhagic stroke in the neck dissection group, while 0.3% (13/4,164) of participants had suffered hemorrhagic stroke in the control group (P = 0.085). In total, 0.8% (8/1,041) of participants had suffered an ischemic stroke in the neck dissection group, and 0.7% (31/4,133) of participants had suffered an ischemic stroke in the control group (P = 0.936). The adjusted hazard ratio for ischemic stroke after neck dissection was 1.06 (95% confidence interval [CI] = 0.49–2.31, P = 0.884).

Conclusion

The risk of hemorrhagic or ischemic stroke was not higher in thyroid cancer patients who underwent neck dissection than that in the matched control group.

Risk of Arterial Thromboembolism in Patients With Cancer

BACKGROUND

The risk of arterial thromboembolism in patients with cancer is incompletely understood.

OBJECTIVES

The authors aimed to better define this epidemiological relationship, including the effects of cancer stage.

METHODS

Using the Surveillance Epidemiology and End Results-Medicare linked database, the authors identified patients with a new primary diagnosis of breast, lung, prostate, colorectal, bladder, pancreatic, or gastric cancer or non-Hodgkin lymphoma from 2002 to 2011. They were individually matched by demographics and comorbidities to a Medicare enrollee without cancer, and each pair was followed through 2012. Validated diagnosis codes were used to identify arterial thromboembolism, defined as myocardial infarction or ischemic stroke. Cumulative incidence rates were calculated using competing risk survival statistics. Cox hazards analysis was used to compare rates between groups at discrete time points.

RESULTS

The authors identified 279,719 pairs of patients with cancer and matched control patients. The 6-month cumulative incidence of arterial thromboembolism was 4.7% (95% confidence interval [CI]: 4.6% to 4.8%) in patients with cancer compared with 2.2% (95% CI: 2.1% to 2.2%) in control patients (hazard ratio [HR]: 2.2; 95% CI: 2.1 to 2.3). The 6-month cumulative incidence of myocardial infarction was 2.0% (95% CI: 1.9% to 2.0%) in patients with cancer compared with 0.7% (95% CI: 0.6% to 0.7%) in control patients (HR: 2.9; 95% CI: 2.8 to 3.1). The 6-month cumulative incidence of ischemic stroke was 3.0% (95% CI: 2.9% to 3.1%) in patients with cancer compared with 1.6% (95% CI: 1.6% to 1.7%) in control patients (HR: 1.9; 95% CI: 1.8 to 2.0). Excess risk varied by cancer type (greatest for lung), correlated with cancer stage, and generally had resolved by 1 year.

CONCLUSIONS

Patients with incident cancer face a substantially increased short-term risk of arterial thromboembolism.

Human Papillomavirus Status and the Risk of Cerebrovascular Events Following Radiation Therapy for Head and Neck Cancer

Background

Radiation therapy (RT) is a standard treatment for head and neck cancer; however, it is associated with inflammation, accelerated atherosclerosis, and cerebrovascular events (CVEs; stroke or transient ischemic attack). Human papillomavirus (HPV) is found in nearly half of head and neck cancers and is associated with inflammation and atherosclerosis. Whether HPV confers an increased risk of CVEs after RT is unknown.

Methods and Results

Using an institutional database, we identified all consecutive patients treated with RT from 2002 to 2012 for head and neck cancer who were tested for HPV. The outcome of interest was the composite of ischemic stroke and transient ischemic attack, and the association between HPV and CVEs was assessed using Cox proportional hazard models, competing risk analysis, and inverse probability weighting. Overall, 326 participants who underwent RT for head and neck cancer were tested for HPV (age 59±12 years, 75% were male, 9% had diabetes mellitus, 45% had hypertension, and 61% were smokers), of which 191 (59%) were tumor HPV positive. Traditional risk factors for CVEs were similar between HPV‐positive and ‐negative patients. Over a median follow‐up of 3.4 years, there were 18 ischemic strokes and 5 transient ischemic attacks (event rate of 1.8% per year). The annual event rate was higher in the HPV‐positive patients compared with the HPV‐negative patients (2.6% versus 0.9%, P=0.002). In a multivariable model, HPV‐positive status was associated with a >4 times increased risk of CVEs (hazard ratio: 4.4; 95% confidence interval, 1.5–13.2; P=0.008).

Conclusions

In this study, HPV‐positive status is associated with an increased risk of stroke or transient ischemic attack following RT for head and neck cancer.

Risk of Cerebrovascular Events in 178 962 Five-Year Survivors of Cancer Diagnosed at 15 to 39 Years of Age: The TYACSS (Teenage and Young Adult Cancer Survivor Study)

BACKGROUND

Survivors of teenage and young adult cancer are at risk of cerebrovascular events, but the magnitude of and extent to which this risk varies by cancer type, decade of diagnosis, age at diagnosis, and attained age remains uncertain. This is the largest-ever cohort study to evaluate the risks of hospitalization for a cerebrovascular event among long-term survivors of teenage and young adult cancer.

METHODS

The population-based TYACSS (Teenage and Young Adult Cancer Survivor Study) (N=178,962) was linked to Hospital Episode Statistics data for England to investigate the risks of hospitalization for a cerebrovascular event among 5-year survivors of cancer diagnosed when 15 to 39 years of age. Observed numbers of first hospitalizations for cerebrovascular events were compared with that expected from the general population using standardized hospitalization ratios (SHRs) and absolute excess risks per 10 000 person-years. Cumulative incidence was calculated with death considered a competing risk.

RESULTS

Overall, 2782 cancer survivors were hospitalized for a cerebrovascular event-40% higher than expected (SHR=1.4, 95% confidence interval, 1.3-1.4). Survivors of central nervous system (CNS) tumors (SHR=4.6, 95% confidence interval, 4.3-5.0), head and neck tumors (SHR=2.6, 95% confidence interval, 2.2-3.1), and leukemia (SHR=2.5, 95% confidence interval, 1.9-3.1) were at greatest risk. Males had significantly higher absolute excess risks than females (absolute excess risks =7 versus 3), especially among head and neck tumor survivors (absolute excess risks =30 versus 11). By 60 years of age, 9%, 6%, and 5% of CNS tumor, head and neck tumor, and leukemia survivors, respectively, had been hospitalized for a cerebrovascular event. Beyond 60 years of age, every year, 0.4% of CNS tumor survivors were hospitalized for a cerebral infarction (versus 0.1% expected), whereas at any age, every year, 0.2% of head and neck tumor survivors were hospitalized for a cerebral infarction (versus 0.06% expected).

CONCLUSIONS

Survivors of a CNS tumor, head and neck tumor, and leukemia are particularly at risk of hospitalization for a cerebrovascular event. The excess risk of cerebral infarction among CNS tumor survivors increases with attained age. For head and neck tumor survivors, this excess risk remains high across all ages. These groups of survivors, particularly males, should be considered for surveillance of cerebrovascular risk factors and potential pharmacological interventions for cerebral infarction prevention.

Evaluating the Primary Prevention of Ischemic Stroke of Oral Antithrombotic Therapy in Head and Neck Cancer Patients with Radiation Therapy

Although previous studies demonstrated the risk of ischemic stroke (IS) in patients with head and neck cancer (HNC), the impact of oral antithrombotic therapy (OAT) on this risk has not yet been assessed. We aimed to evaluate the effectiveness and safety of OAT in patients with HNC treated with RT. This retrospective cohort study was performed using the National Health Insurance Research Database of Taiwan. A total of 37,638 patients diagnosed with HNC included in the study were classified as users and nonusers of OAT. Primary outcome was IS or transient ischemic attack (TIA), and secondary outcomes were death and major bleeding. The Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). There was no significant difference in the risk of IS or TIA between patients on continuous OAT and nonusers (adjusted HR, 0.812; 95% CI, 0.199-3.309). The risk of major bleeding was not significantly different between the groups. From a national population database, we did not find an association between OAT and decreasing risk of ischemic stroke/TIA or increasing hazard of major bleeding.

Posterior Reversible Encephalopathy Syndrome During Combined Modality Therapy for Head and Neck Squamous Cell Carcinoma

OBJECTIVES

Posterior reversible encephalopathy syndrome (PRES) is a rare and acute disease with central nervous system symptoms. Without appropriate therapy, patients may exhibit a poor prognosis. PRES should be recognized as a possible problem during therapy for head and neck squamous cell carcinoma (HNSCC).

METHODS

A 56-year-old female developed PRES during combined modality therapy for HNSCC. On the fourth day after surgery and following chemoradiotherapy, PRES developed with a sudden visual disorder, followed by headache located at the back of the head and convulsions accompanied by impaired consciousness. We diagnosed PRES based on the clinical manifestations and magnetic resonance imaging data.

RESULTS

The patient recovered from PRES by appropriate treatment.

CONCLUSION

This is the first case report of PRES developed during treatment for HNSCC. Masked by other cerebrovascular disorders, more cases of PRES could exist than usually expected; therefore, we should consider PRES as a differential diagnosis for central nervous system disorders developing during high-intensity therapy.

Cardiovascular Complications of Cranial and Neck Radiation

OPINION STATEMENT

Cancer survivors who receive head and neck radiation are at increased risk for cerebrovascular events. This is mediated via damage to the hypothalamus-pituitary axis leading to the metabolic syndrome and extracranial arterial injury leading to carotid artery stenosis. Head and neck radiation can also lead to intracranial injury that can present as moyamoya, especially in children. Survivors require lifelong periodic follow-up for the development of pan-hypopituitarism or its individual components as well as for dyslipidemia and obesity. Aggressive control of traditional cardiovascular risk factors is recommended to reduce cardiovascular morbidity and mortality. There are no specific guidelines for the surveillance and management of asymptomatic carotid artery disease in cancer survivors. However, regular detailed examination for carotid bruits and neurological symptoms is recommended. Treatment of significant radiation-induced carotid artery disease has not been specifically studied and is based upon recommendations for patients with atherosclerotic carotid stenosis. Carotid endarterectomy can be difficult in radiation patients due to anatomic concerns and the risk of post-operative cranial nerve injury and wound complications but should be considered in patients with suitable anatomy and neck architecture. Carotid artery stenting, while successful, may be associated with greater long-term mortality and neurologic complications. Regardless of the strategy employed, radiation patients are at increased risk for restenosis and should undergo routine surveillance even after revascularization.

Risk of Ischemic Stroke in Patients With Gastric Cancer: A Nationwide Population-Based Cohort Study

Improvements in therapeutic modalities have prolonged the survival of gastric cancer patients. Comorbidities such as thromboembolic events that emerge as a result of disease complexities and/or treatments received have not been considered. The objectives of this study are to examine the relationship between gastric cancer and ischemic stroke, and to determine predictive risk factors. A nationwide population-based cohort study was conducted using data from the Taiwan National Health Insurance database. A total of 45,060 gastric cancer patients and non-cancer counterparts without antecedent stroke were recruited. Hazard ratios (HRs) and the cumulative incidence of ischemic stroke were calculated, and risk factors for ischemic stroke were assessed. Gastric cancer patients were associated with higher risk of ischemic stroke (HR 1.11, 95% confidence interval [CI] 1.03-1.19, P = 0.007), especially in participants younger than 65 years (HR 1.61, 95% CI 1.39-1.86, P < 0.001) and in female participants (HR 1.30, 95% CI 1.14-1.49; P < 0.001) when compared with the matched cohort. Independent risk factors of ischemic stroke in gastric cancer patients included age, hypertension, atrial fibrillation, dyslipidemia, and having received major surgery for gastric cancer. Our findings suggest the importance of stroke surveillance and prevention strategies in high-risk patients. Having received major surgery for gastric cancer is a significant risk factor in these patients.

Association between incident cancer and subsequent stroke

OBJECTIVE

A study was undertaken to examine the association between incident cancer and the subsequent risk of stroke.

METHODS

Using the Surveillance, Epidemiology, and End Results-Medicare linked database, we identified patients with a new primary diagnosis of breast, colorectal, lung, pancreatic, or prostate cancer from 2001 through 2007. These patients were individually matched by age, sex, race, registry, and medical comorbidities to a group of Medicare enrollees without cancer, and each pair was followed through 2009. Validated diagnosis codes were used to identify a primary outcome of stroke. Cumulative incidence rates were calculated using competing risk survival statistics.

RESULTS

Among 327,389 pairs of cancer patients and matched controls, the 3-month cumulative incidence of stroke was generally higher in patients with cancer. Cumulative incidence rates were 5.1% (95% confidence interval [CI] = 4.9-5.2%) in patients with lung cancer compared to 1.2% (95% CI = 1.2-1.3%) in controls (p < 0.001), 3.4% (95% CI = 3.1-3.6%) in patients with pancreatic cancer compared to 1.3% (95% CI = 1.1-1.5%) in controls (p < 0.001), 3.3% (95% CI = 3.2-3.4%) in patients with colorectal cancer compared to 1.3% (95% CI = 1.2-1.4%) in controls (p < 0.001), 1.5% (95% CI = 1.4-1.6%) in patients with breast cancer compared to 1.1% (95% CI = 1.0-1.2%) in controls (p < 0.001), and 1.2% (95% CI = 1.1-1.3%) in patients with prostate cancer compared to 1.1% (95% CI = 1.0-1.2%) in controls (p = 0.085). Excess risks attenuated over time and were generally no longer present beyond 1 year.

INTERPRETATION

Incident cancer is associated with an increased short-term risk of stroke. This risk appears highest with lung, pancreatic, and colorectal cancers.

Risk of ischemic stroke in patients with ovarian cancer: a nationwide population-based study

BACKGROUND

Cancer patients are at risk of thromboembolism. However, studies investigating the relationship between ovarian cancer and ischemic stroke are lacking. The objectives of this study were to assess the association between ovarian cancer and ischemic stroke, and to determine the predictive risk factors.

METHODS

Ovarian cancer patients aged 20 years and older without antecedent cerebrovascular events and who were followed up for more than 1 year between 1 January 2003 and 31 December 2011 were recruited from the Taiwan National Health Insurance database. Hazard ratios (HRs) of stroke risk for ovarian cancer patients compared with an age- and comorbidity-matched cohort were calculated by Cox proportional regression analysis. The difference in cumulative ischemic stroke incidence between ovarian cancer patients and the matched cohort was analyzed with the Kaplan-Meier method and tested with the log-rank test.

RESULTS

Each cohort (ovarian cancer and matched cohort) consisted of 8,810 individuals, with a median age of 49 years. After a median follow-up of 2.68 and 3.85 years, respectively, the ischemic stroke incidence was 1.38-fold higher in the ovarian cancer cohort than in the comparison cohort (9.4 versus 6.8 per 1,000 person-years), with an age- and comorbidity-adjusted HR of 1.49 (P <0.001). The ischemic stroke risk imposed by ovarian cancer was more prominent in patients under 50 years old (HR 2.28; P <0.001) compared with patients 50 years and older (HR 1.33; P = 0.005). Significant risk factors predicting stroke development were age 50 years and older (HR 2.21; P <0.001), hypertension (HR 1.84; P <0.001), diabetes mellitus (HR 1.71; P <0.001), and treatment with chemotherapy (HR 1.45; P = 0.017), especially platinum-based regimens.

CONCLUSIONS

Ovarian cancer patients were at an increased risk of developing ischemic stroke. Age, hypertension, diabetes, and chemotherapy treatment were independent risk factors.

Stroke and Cancer- A Complicated Relationship

The interrelationship between stroke and cancer is complex. Cancer and stroke may occur independently in a given patient, or cancer may directly or indirectly lead to stroke via: hypercoaguability, non-bacterial thrombotic endocarditis (NBTE), direct tumor compression of blood vessels, or treatment-related effects which potentiate stroke. Patients with cryptogenic stroke are relatively common, and under the right circumstances, may provide an opportunity to screen for occult malignancy. In this review, we discuss relevant data linking stroke and cancer as well as propose a testable algorithm for cancer screening in the patient with cryptogenic stroke. Future directions should focus on validating patient-care algorithms in prospective clinical trials to provide an evidence base for this important issue.

Incidence of pneumonia and risk factors among patients with head and neck cancer undergoing radiotherapy

BACKGROUND

This study investigated the incidence and patient- and treatment-related risk factors related to pneumonia acquired during radiotherapy (PNRT) in head and neck cancer (HNC) patients.

METHODS

Using the universal insurance claims data, 15,894 total HNC patients between 1998 and 2007 were included in this analysis. PNRT was defined as the occurrence of pneumonia within 90 days of the commencement of radiotherapy. Information also included some demographic characteristics, treatment-related factors, and comorbidities. Appropriate statistical tests were performed to assess the difference between patients with and those without PNRT. A logistic regression was used to estimate the odds ratio (OR) of PNRT among the variables examined.

RESULTS

In total, 772 patients (4.86%) were identified with PNRT as the case group, whereas 15,122 subjects of the same cancer without PNRT formed the control group. Of patients with PNRT, 632 (81.9%) were hospitalized with a mean length of stay of 25.9 days. Results from the multiple logistic regression showed that an older age and certain comorbidities were associated with an increased risk of PNRT. Patients with cancer of the tongue, buccal mucosa, oropharynx, and hypopharynx/larynx were at particularly higher risk (OR = 1.28, 1.28, 1.67, and 1.74, respectively). Compared to radiotherapy alone, concurrent chemoradiotherapy had no effect on the PNRT. Patients in the PNRT group had higher overall medical costs and length of stay.

CONCLUSION

The incidence of PNRT in HNC patients receiving radiotherapy was approximately 5%. Notably, an older age, certain comorbidities, and certain specific tumor sites were associated with an increased risk.

Trends in cancer diagnoses among inpatients hospitalized with stroke

BACKGROUND

Cancer, by conferring a hypercoagulable state, may lead to an ischemic stroke. Relatively little is known about the prevalence and evolution of cancer among stroke patients over the last decade.

METHODS

We used the Nationwide Inpatient Sample to identify discharges with any InternationalClassification of Diseases, Ninth Revision, diagnosis code for cancer and ischemic stroke from 1997 to 2006. We then calculated age-adjusted yearly acute ischemic stroke hospitalization rates among adult populations with and without cancer.

RESULTS

Prevalence of cancer among hospitalized stroke patients increased from 1997 to 2006 (N = 31,075 [9.1% of all ischemic stroke hospitalizations] to 34,138 [10.6%], P < .0001). The most common types of cancer among hospitalized stroke patients in 1997 and 2006 were prostate (21% versus 19%), breast (19% versus 19%), gastrointestinal (16% versus 13%), and colorectal (13% versus 13%). Over the decade there was a significant decrease in the prevalence of stroke hospitalizations (slope -3.02, 95% confidence interval -3.69 to -2.34), but not among cancer patients (slope 1.35, 95% confidence interval -0.88 to 3.58).

CONCLUSION

About 1 in 10 hospitalized ischemic stroke patients in the United States has comorbid cancer, and there has been a slight rise in this rate over the last decade. This is likely due to enhanced survival from better cancer treatments, but further study is warranted.

Vascular injury in cancer survivors

With an increase in the number of patients surviving many years following successful cancer treatment, has come an improved understanding of the long-term effects of cancer therapy and its implications on future health. Premature cardiovascular disease is a significant cause of early morbidity and the leading non-cancer cause of death in this population. Chemotherapeutic agents and radiation therapy are known to be cardiotoxic. However, numerous vascular-related toxicities have also been observed among cancer survivors, such as myocardial ischemia, transient ischemic attacks, and stroke, suggesting a degree of chronic endothelial injury and dysfunction leading to premature atherosclerotic disease. Vascular health in cancer survivors may be further compromised by metabolic abnormalities such as obesity, insulin resistance, and dyslipidemias which have also been reported following cancer therapy. Furthermore, some survivors experience gonadal dysfunction and loss of potentially protective sex steroids or undergo hormonal therapies that induce additional metabolic abnormalities. The effects of cancer therapies upon the endothelial monolayer have not been fully explored. An understanding of potential injury to and dysfunction of the circulatory system among cancer survivors is essential for identifying preventive strategies and therapeutic targets.