Development of a score for prediction of occult malignancy in stroke patients (occult-5 score)

Diagnosing cancer-associated ischemic stroke: A systematic review of hematological biomarkers

BACKGROUND AND AIM

Patients suffering from cancer are reported to have an increased risk of ischemic stroke (IS). We aimed to identify cancer-associated biomarkers found to differentiate between IS associated with cancer from those not associated with cancer.

SUMMARY OF REVIEW

We performed a systematic search of PubMed and EMBASE databases according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The study is reported in PROSPERO (#CRD42022355129). In total, 5563 papers were screened, of which 49 papers were included. Seven biomarkers were identified which had the potential to differentiate between patients who had cancer or stroke or both conditions. D-dimer was the most frequently monitored biomarker, and high levels were significantly associated with cancer-related strokes in (42/44) studies. Fibrinogen was significantly associated with cancer-related strokes in 11/27 studies. A higher level of C-reactive protein, investigated in 19 studies, was associated with cancer-related strokes, but conclusive multivariate analysis was not performed. Finally, the four cancer-associated antigens CA125, CA153, CA199, and carcinoembryonic antigen were only reported on in three to six studies, respectively. These studies all originated from the Guangxi province in China. CA125 was associated with an increased risk of IS in four of six studies.

CONCLUSION

Increased D-dimer seems associated with cancer-related IS. CRP may also be a candidate as a cancer-associated stroke biomarker, but this requires further verification. Fibrinogen and the more specific cancer biomarkers have not yet been proven helpful for detecting cancer-related strokes.

Prevalence of right-to-left shunt in stroke patients with cancer

BACKGROUND AND OBJECTIVES

Cancer is associated with an increased risk of acute ischemic stroke (AIS) and venous thromboembolism. The role of a cardiac right-to-left shunt (RLS) as a surrogate parameter for paradoxical embolism in cancer-related strokes is uncertain. We sought to investigate the relationship between the presence of an RLS and cancer in AIS patients.

METHODS

We included consecutive AIS patients hospitalized at our tertiary stroke center between January 2015 and December 2020 with available RLS status as detected on transesophageal echocardiography (TEE). Active cancers were retrospectively identified and the association with RLS was assessed with multivariable logistic regression and inverse probability of treatment weighting to minimize the ascertainment bias of having a TEE obtained.

RESULTS

Of the 2236 AIS patients included, 103 (4.6%) had active cancer, of whom 24 (23%) were diagnosed with RLS. An RLS was present in 774 out of the 2133 AIS patients without active cancer (36%). After adjustment and weighting, the absence of RLS was associated with active cancer (adjusted odds ratio (aOR) 2.29; 95% confidence interval (CI), 1.14-4.58). When analysis was restricted to patients younger than 60 years of age or those with a high-risk RLS (Risk of Paradoxical Embolism Score ⩾ 6), there was no association between RLS and cancer (aOR, 3.07; 95% CI, 0.79-11.88 and aOR, 0.56; 95% CI, 0.10-3.10, respectively).

CONCLUSION

RLS was diagnosed less frequently in AIS patients with cancer than in cancer-free patients, suggesting that arterial sources may play a larger role in cancer-related strokes than paradoxical venous embolization. Future studies are needed to validate these findings and evaluate potential therapeutic implications, such as the general indication, or lack thereof, for patent foramen ovale (PFO) closure in this patient population.

Embolic strokes of undetermined source: a clinical consensus statement of the ESC Council on Stroke, the European Association of Cardiovascular Imaging and the European Heart Rhythm Association of the ESC

One in six ischaemic stroke patients has an embolic stroke of undetermined source (ESUS), defined as a stroke with unclear aetiology despite recommended diagnostic evaluation. The overall cardiovascular risk of ESUS is high and it is important to optimize strategies to prevent recurrent stroke and other cardiovascular events. The aim of clinicians when confronted with a patient not only with ESUS but also with any other medical condition of unclear aetiology is to identify the actual cause amongst a list of potential differential diagnoses, in order to optimize secondary prevention. However, specifically in ESUS, this may be challenging as multiple potential thromboembolic sources frequently coexist. Also, it can be delusively reassuring because despite the implementation of specific treatments for the individual pathology presumed to be the actual thromboembolic source, patients can still be vulnerable to stroke and other cardiovascular events caused by other pathologies already identified during the index diagnostic evaluation but whose thromboembolic potential was underestimated. Therefore, rather than trying to presume which particular mechanism is the actual embolic source in an ESUS patient, it is important to assess the overall thromboembolic risk of the patient through synthesis of the individual risks linked to all pathologies present, regardless if presumed causally associated or not. In this paper, a multi-disciplinary panel of clinicians/researchers from various backgrounds of expertise and specialties (cardiology, internal medicine, neurology, radiology and vascular surgery) proposes a comprehensive multi-dimensional assessment of the overall thromboembolic risk in ESUS patients through the composition of individual risks associated with all prevalent pathologies.

Ischemic Stroke in Cancer: Mechanisms, Biomarkers, and Implications for Treatment

Ischemic stroke is an important cause of morbidity and mortality in cancer patients. The underlying mechanisms linking cancer and stroke are not completely understood. Long-standing and more recent evidence suggests that cancer-associated prothrombotic states, along with treatment-related vascular toxicity, such as with chemotherapy and immunotherapy, contribute to an increased risk of ischemic stroke in cancer patients. Novel biomarkers, including coagulation, platelet and endothelial markers, cell-free DNA, and extracellular vesicles are being investigated for their potential to improve risk stratification and patient selection for clinical trials and to help guide personalized antithrombotic strategies. Treatment of cancer-related stroke poses unique challenges, including the need to balance the risk of recurrent stroke and other thromboembolic events with that of bleeding associated with antithrombotic therapy. In addition, how and when to restart cancer treatment after stroke remains unclear. In this review, we summarize current knowledge on the mechanisms underlying ischemic stroke in cancer, propose an etiological classification system unique to cancer-related stroke to help guide patient characterization, provide an overview of promising biomarkers and their clinical utility, and discuss the current state of evidence-based management strategies for cancer-related stroke. Ultimately, a personalized approach to stroke prevention and treatment is required in cancer patients, considering both the underlying cancer biology and the individual patient's risk profile.

Systematic review and meta-analysis of studies comparing baseline D-dimer level in stroke patients with or without cancer: Strength of current evidence

Objectives

D-dimer levels are increased in stroke and cancer. Cancer patients are at a higher risk of stroke. However, the evidence is unclear if high D-dimer in stroke patients can suggest the diagnosis of concomitant cancer or the development of stroke in a cancer patient. The objective is to assess the evidence available on the baseline D-dimer level in stroke patients with and without cancer.

Materials and Methods

We conducted the systematic review and meta-analysis using the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. We searched PUBMED, Cochrane, ScienceDirect, and Scopus for potentially eligible articles published till June 2023. All the review steps were iterative and done independently by two reviewers. The Newcastle-Ottawa scale tool was used to assess the quality of included studies for case control and cohort studies and the Agency for Healthcare Research and Quality tool for cross-sectional studies. The qualitative synthesis is presented narratively, and quantitative synthesis is shown in the forest plot using the random effects model. I2 of more than 60% was considered as high heterogeneity.

Results

The searches from all the databases yielded 495 articles. After the study selection process, six papers were found eligible for inclusion in the qualitative and quantitative synthesis. In the present systematic review, 2651 patients with ischemic infarcts are included of which 404 (13.97%) patients had active cancer while 2247 (86.02%) did not. The studies included were of high quality and low risk of bias. There were significantly higher baseline D-dimer levels in stroke patients with cancer than in non-cancer patients with a mean difference of 4.84 (3.07-6.60) P < 0.00001.

Conclusion

D-dimer is a simple and relatively non-expensive biomarker that is increased to significant levels in stroke patients, who have cancer and therefore may be a tool to predict through screening for active or occult cancer in stroke patients.

Transient ischemic attacks in patients with active and occult cancer

Background and aim

Paraneoplastic coagulopathy can present as stroke and is associated with specific biomarker changes. Identifying paraneoplastic coagulopathy can help guide secondary prevention in stroke patients, and early cancer detection might improve outcomes. However, unlike ischemic stroke, it remains unclear whether paraneoplastic coagulopathy is associated with transient ischemic attacks (TIA). This study assessed the presence of cancer-related biomarkers in TIA patients and evaluated long-term mortality rates in patients with and without active cancer.

Methods

Active cancer was retrospectively identified in consecutive TIA patients treated at a comprehensive stroke center between 2015 and 2019. An association between the presence of cancer and cancer-related biomarkers was assessed using multivariable logistic regression. Long-term mortality after TIA was analyzed using multivariable Cox regression.

Results

Among 1436 TIA patients, 72 had active cancer (5%), of which 17 were occult (1.2%). Cancer-related TIA was associated with male gender (adjusted odds ratio [aOR] 2.29, 95% CI 1.12-4.68), history of smoking (aOR 2.77, 95% CI 1.34-5.7), elevated D-dimer (aOR 1.77, 95% CI 1.26-2.49), lactate dehydrogenase (aOR 1.003, 95% CI 1.00-1.005), lower leukocyte count (aOR 1.20, 95% CI 1.04-1.38), and lower hemoglobin (aOR 1.02, 95% CI 1.00-1.04). Long-term mortality was associated with both active cancer (adjusted hazard ratios [aHR] 2.47, 95% CI 1.58-3.88) and occult cancer (aHR 3.08, 95% CI 1.30-7.32).

Conclusion

Cancer-related TIA is not uncommon. Biomarkers known to be associated with cancer-related stroke also seem to be present in TIA patients. Early identification would enable targeted treatment strategies and could improve outcomes in this patient population.

Clinical and Demographic Characteristics, Mechanisms, and Outcomes in Patients With Acute Ischemic Stroke and Newly Diagnosed or Known Active Cancer

BACKGROUND AND OBJECTIVES

Patients with a new diagnosis of cancer carry an increased risk of acute ischemic stroke (AIS), and this risk varies depending on age, cancer type, stage, and time from diagnosis. Whether patients with AIS with a new diagnosis of neoplasm represent a distinct subset from those with a previously known active malignancy remains unclear. We aimed to estimate the rate of stroke in patients with newly diagnosed cancer (NC) and previously known active cancer (KC) and to compare the demographic and clinical features, stroke mechanisms, and long-term outcomes between groups.

METHODS

Using 2003-2021 data from the Acute STroke Registry and Analysis of Lausanne registry, we compared patients with KC with patients with NC (cancer identified during AIS hospitalization or within the following 12 months). Patients with inactive and no history of cancer were excluded. Outcomes were the modified Rankin scale (mRS) score at 3 months and mortality and recurrent stroke at 12 months. We used multivariable regression analyses to compare outcomes between groups while adjusting for important prognostic variables.

RESULTS

Among 6,686 patients with AIS, 362 (5.4%) had active cancer (AC), including 102 (1.5%) with NC. Gastrointestinal and genitourinary cancers were the most frequent cancer types. Among all patients with AC, 152 (42.5%) AISs were classified as cancer related, with nearly half of these cases attributed to hypercoagulability. In multivariable analysis, patients with NC had less prestroke disability (adjusted odds ratio [aOR] 0.62, 95% CI 0.44-0.86) and fewer prior stroke/transient ischemic attack events (aOR 0.43, 95% CI 0.21-0.88) than patients with KC. Three-month mRS scores were similar between cancer groups (aOR 1.27, 95% CI 0.65-2.49) and were predominantly driven by the presence of newly diagnosed brain metastases (aOR 7.22, 95% CI 1.49-43.17) and metastatic cancer (aOR 2.19, 95% CI 1.22-3.97). At 12 months, mortality risk was higher in patients with NC vs patients with KC (hazard ratio [HR] 2.11, 95% CI 1.38-3.21), while recurrent stroke risk was similar between groups (adjusted HR 1.27, 95% CI 0.67-2.43).

DISCUSSION

In a comprehensive institutional registry spanning nearly 2 decades, 5.4% of patients with AIS had AC, a quarter of which were diagnosed during or within 12 months after the index stroke hospitalization. Patients with NC had less disability and prior cerebrovascular disease, but a higher 1-year risk of subsequent death than patients with KC.

A risk model for prediction of diagnosis of cancer after ischemic stroke

It remains controversial which characteristics may predict occult cancer in stroke patients. Characteristics of patients with ischemic stroke registered in the Zurich Swiss Stroke Registry (2014 to 2016) were tested for associations with cancer diagnosis after stroke with consideration of death as competing risk for cancer diagnosis. Among 1157 patients, 34 (3%) and 55 patients (5%) were diagnosed with cancer within 1 and 3 years after stroke. Levels of white blood cells (WBC) > 9,600/µl (subdistribution hazard ratio (SHR) 3.68, p = 0.014), platelets > 400,000/µl (SHR 7.71, p = 0.001), and d-dimers ≥ 3 mg/l (SHR 3.67, p = 0.007) were independently associated with cancer diagnosis within 1 year after stroke. Occurrence of ischemic lesions in ≥ 2 vascular territories not attributed to cardioembolic etiology was associated with cancer diagnosed within 1 year after stroke in univariable analysis (SHR 3.69, p = 0.001). The area under the curve of a score from these parameters (score sum 0-4) was 0.73. A score of ≥ 2 had a sensitivity of 43% and specificity of 92% for prediction of cancer diagnosis within 1 year after stroke. We suggest further validation of a score of WBC, platelets, d-dimers and multiple ischemic lesions without cardioembolic stroke etiology for prediction of cancer diagnosis after stroke.

Absence of susceptibility vessel sign and hyperdense vessel sign in patients with cancer-related stroke

Background and aim

Identification of paraneoplastic hypercoagulability in stroke patients helps to guide investigations and prevent stroke recurrence. A previous study demonstrated an association between the absence of the susceptibility vessel sign (SVS) on brain MRI and active cancer in patients treated with mechanical thrombectomy. The present study aimed to confirm this finding and assess an association between the absence of the hyperdense vessel sign (HVS) on head CT and active cancer in all stroke patients.

Methods

SVS and HVS status on baseline imaging were retrospectively assessed in all consecutive stroke patients treated at a comprehensive stroke center between 2015 and 2020. Active cancer, known at the time of stroke or diagnosed within 1 year after stroke (occult cancer), was identified. Adjusted odds ratios (aOR) and their 95% confidence interval (CI) for the association between the thrombus imaging characteristics and cancer were calculated using multivariable logistic regression.

Results

Of the 2,256 patients with thrombus imaging characteristics available at baseline, 161 had an active cancer (7.1%), of which 36 were occult at the time of index stroke (1.6% of the total). The absence of SVS was associated with active cancer (aOR 3.14, 95% CI 1.45-6.80). No significance was reached for the subgroup of occult cancer (aOR 3.20, 95% CI 0.73-13.94). No association was found between the absence of HVS and active cancer (aOR 1.07, 95% CI 0.54-2.11).

Conclusion

The absence of SVS but not HVS could help to identify paraneoplastic hypercoagulability in stroke patients with active cancer and guide patient care.