Do traditional risk stratification models for cerebrovascular events apply in irradiated head and neck cancer patients?

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.

Risk of Cardiovascular Events Among Patients With Head and Neck Cancer

Importance

Cardiovascular (CV) disease is a substantial cause of morbidity and mortality in cancer due to shared risk factors and exposure to potentially cardiotoxic cancer therapy. However, our understanding of CV risk in patients with head and neck squamous cell carcinoma (HNSCC) is limited.

Objective

To define CV risk profiles, incident stroke, myocardial infarction (MI), and mortality in patients with HNSCC.

Design, Setting, and Participants

This retrospective, population-based cohort study included 35 897 US veterans with newly diagnosed HNSCC from January 1, 2000, to December 31, 2020. Data were analyzed from May 2022 to January 2023.

Exposures

Demographic, cancer-specific, and treatment characteristics.

Main Outcomes

Prevalence of CV risk factors, medication use, and control at HNSCC diagnosis; cumulative incidence of stroke and MI; and all-cause death.

Results

Of 35 857 US veterans with HNSCC (median [IQR] age, 63 [58-69] years; 176 [0.5%] American Indian or Alaska Native, 57 [0.2%] Asian, 5321 [16.6%] Black, 207 [0.6%] Native Hawaiian or Other Pacific Islander, and 26 277 [82.0%] White individuals), there were high rates of former or current smoking (16 341 [83%]), hypertension (24 023 [67%]), diabetes (7988 [22%]), and hyperlipidemia (18 421 [51%]). Although most patients were taking risk-lowering medications, 15 941 (47%) had at least 1 uncontrolled CV risk factor. Black race was associated with increased risk of having uncontrolled CV risk factor(s) (relative risk, 1.06; 95% CI, 1.03-1.09), and patients with larynx cancer had higher rates of prevalent and uncontrolled risk factors compared with other cancer subsites. Considering death as a competing risk, the 10-year cumulative incidence of stroke and MI was 12.5% and 8.3%, respectively. In cause-specific hazards models, hypertension, diabetes, carotid artery stenosis, coronary artery disease, and presence of uncontrolled CV risk factor(s) were significantly associated with stroke and MI. In extended Cox models, incident stroke and MI were associated with a 47% (95% CI, 41%-54%) and 71% (95% CI, 63%-81%) increased risk of all-cause death, respectively.

Conclusion

The results of this cohort study suggest that in HNSCC, the burden of suboptimally controlled CV risk factors and incident risk of stroke and MI are substantial. Modifiable CV risk factors are associated with risk of adverse CV events, and these events are associated with a higher risk of death. These findings identify populations at risk and potentially underscore the importance of modifiable CV risk factor control and motivate strategies to reduce CV risk in HNSCC survivorship care.

Traditional risk factors and cancer-related factors associated with cardiovascular disease risk in head and neck cancer patients

Background

Risk of incident cardiovascular disease (CVD) in head and neck squamous cell carcinoma (HNSCC) patients is under-reported. We assessed the association of HNSCC-related factors and traditional risk factors with 1- and 5-year CVD risk in HNSCC patients without prevalent CVD at cancer diagnosis.

Methods

A clinical cohort of 1,829 HNSCC patients diagnosed between 2012 and 2018, at a National Cancer Institute (NCI)-designated cancer center was included. Information on HNSCC-related factors [HNSCC anatomical subsite, stage at diagnosis, treatment, and tumor human papillomavirus (HPV) status] were extracted from the tumor registry. Data on traditional risk factors (hypertension, dyslipidemia, diabetes, tobacco smoking status, and obesity) were extracted from the electronic health records system (EHR) at baseline (HNSCC diagnosis). A composite of ischemic heart disease, heart failure, and ischemic stroke was the outcome of interest in time to event analysis. Hazard ratio (HR) (95% CI) were reported with death as a competing risk.

Results

In patients diagnosed with HNSCC, 10.61% developed incident CVD events by 1-year post cancer diagnosis. One-year CVD risk was lower in patients using antihypertensive medications at baseline, compared to patients without baseline hypertension [HR (95% CI): 0.41 (0.24-0.61)]. One-year CVD risk was high in patients receiving HNSCC surgery. Patients receiving radiation therapy had a higher 5-year CVD risk than surgery patients [HR (95% CI): 2.17 (1.31-3.04)]. Patients using antihypertensive medications had a lower 5-year CVD risk than patients without baseline hypertension [HR (95% CI): 0.45 (0.22-0.75)]. Older age and diabetes were associated with increased 1- and 5-year CVD risk. HPV-negative patients were older (p 0.006) and had a higher 5-year cumulative incidence of CVD (p 0.013) than HPV-positive patients.

Conclusion

Traditional risk factors and cancer-related factors are associated with CVD risk in HNSCC patients. Future research should investigate the role of antihypertensive medications in reducing CVD risk in HNSCC patients.

Risk of ischaemic cerebrovascular events in head and neck cancer patients is associated with carotid artery radiation dose

BACKGROUND AND PURPOSE

Radiotherapy in the head and neck area may cause vascular damage to the carotid arteries, increasing the risk of anterior circulation ischaemic cerebrovascular events (ICVEs). However, limited data exists on the relationship between radiation dose to the carotid arteries and risk of ICVE. The purpose of this study was therefore to determine the relationship between radiation dose to the carotid arteries and anterior circulation ICVE risk.

MATERIALS AND METHODS

A retrospective analysis of a prospective study cohort of 750 head and neck cancer patients treated with definitive (chemo)radiotherapy was performed. Carotid arteries were delineated, and dose-volume parameters of the treatment plans were calculated. ICVEs were scored prospectively and checked retrospectively by analysing all patient records. Cox proportional hazards analysis was performed to analyse the dose-effect relationships.

RESULTS

The median follow-up period was 3.4 years, 27 patients experienced an ICVE and the 5-year cumulative risk was 4.6%. ICVE risk was significantly associated with dose to the carotid arteries. Multivariable analysis showed that the absolute volume (cm³) of the carotid arteries that received at least a radiation dose of 10 Gy was the most important prognostic factor for ICVE (HR = 1.11, AUC = 0.68, p < 0.001).

CONCLUSION

This is the first large prospective cohort study that demonstrates an independent dose-effect relationship between radiation dose to the carotid arteries and the risk of ICVE. These findings may be used to identify patients at risk for ICVE after radiotherapy who may benefit from primary or secondary preventive measures.

A nomogram for the prediction of cerebrovascular disease among patients with brain necrosis after radiotherapy for nasopharyngeal carcinoma

BACKGROUND AND PURPOSE

This study sought to develop and validate a nomogram to predict cerebrovascular disease (CVD) among patients with brain necrosis after radiotherapy for nasopharyngeal carcinoma (NPC).

MATERIALS AND METHODS

A total of 346 eligible patients with brain necrosis after radiotherapy for NPC were divided into a training set (n = 231) and a validation set (n = 115). A multivariate Cox proportional hazards regression model was used to select the significant variables for CVD prediction in the training set. Then, a nomogram was developed based on the regression model. The performance of the nomogram was assessed with respect to discrimination and calibration. All patients were classified into high- or low-risk groups based on the risk scores derived from the nomogram. Moreover, a decision curve analysis was performed with the combined training and validation sets to evaluate the clinical usefulness of the nomogram.

RESULTS

Four significant predictors were identified: hypertension, statin treatment, serum level of high-density lipoprotein, and interval between radiotherapy and brain necrosis. The nomogram incorporating these four predictors showed favorable calibration and discrimination regarding the training set, with a C-index of 0.763 (95% CI, 0.694 to 0.832), which was confirmed using the validation set (C-index 0.768; 95% CI, 0.675 to 0.861). Furthermore, the nomogram successfully stratified patients into high- and low-risk groups. The decision curve indicated that our nomogram was clinically useful.

CONCLUSION

The nomogram showed favorable predictive accuracy for CVD among patients with brain necrosis after radiotherapy for NPC and might aid in clinical decision making.

Head and Neck Cancer Survivorship Care Guideline: American Society of Clinical Oncology Clinical Practice Guideline Endorsement of the American Cancer Society Guideline

Purpose This guideline provides recommendations on the management of adults after head and neck cancer (HNC) treatment, focusing on surveillance and screening for recurrence or second primary cancers, assessment and management of long-term and late effects, health promotion, care coordination, and practice implications. Methods ASCO has a policy and set of procedures for endorsing clinical practice guidelines that have been developed by other professional organizations. The American Cancer Society (ACS) HNC Survivorship Care Guideline was reviewed for developmental rigor by methodologists. An ASCO Expert Panel reviewed the content and recommendations, offering modifications and/or qualifying statements when deemed necessary. Results The ASCO Expert Panel determined that the ACS HNC Survivorship Care Guideline, published in 2016, is clear, thorough, clinically practical, and helpful, despite the limited availability of high-quality evidence to support many of the recommendations. ASCO endorsed the ACS HNC Survivorship Care Guideline, adding qualifying statements aimed at promoting team-based, multispecialty, multidisciplinary, collaborative head and neck survivorship care. Recommendations The ASCO Expert Panel emphasized that caring for HNC survivors requires a team-based approach that includes primary care clinicians, oncology specialists, otolaryngologists, dentists, and other allied professionals. The HNC treatment team should educate the primary care clinicians and patients about the type(s) of treatment received, the likelihood of potential recurrence, and the potential late and long-term complications. Primary care clinicians should recognize symptoms of recurrence and coordinate a prompt evaluation. They should also be prepared to manage late effects either directly or by referral to appropriate specialists. Health promotion is critical, particularly regarding tobacco cessation and dental care. Additional information is available at www.asco.org/HNC-Survivorship-endorsement and www.asco.org/guidelineswiki .