Intensive Screening with FDG PET/CT for Occult Cancer After Stroke

(INCOGNITO Trial)

Overseen By Deborah Siegal, MD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Ottawa Hospital Research Institute

Disqualifiers: Pregnancy, Active cancer, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

45 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to find hidden cancers in individuals who have experienced a cryptogenic stroke, where the cause remains unknown. Researchers seek to determine if using a special scan called FDG PET/CT, alongside regular cancer check-ups, can detect more hidden cancers than regular check-ups alone. This trial may suit those who have recently had a cryptogenic stroke and are interested in additional cancer screening. As an unphased trial, it provides a unique opportunity to contribute to research that could enhance cancer detection methods.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What prior data suggests that FDG PET/CT is safe for cancer screening after stroke?

Research has shown that FDG PET/CT scans, a special imaging test for detecting cancer, are generally safe for patients. This scan uses a small amount of radioactive material to help doctors see inside the body. Studies have found that most people tolerate these scans well.

In a large group of cancer patients, FDG PET/CT scans did not cause serious side effects. Hospitals commonly use this tool to find cancer and assess treatment effectiveness. While any medical test involving radiation carries some risk, the radiation level in FDG PET/CT is low and considered safe.

Individual experiences can vary, so discussing any concerns with a doctor before joining a clinical trial is important. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about using FDG PET/CT for cancer screening after a stroke because it offers a more intensive approach compared to standard screening based on age, sex, and risk factors. This imaging technique can potentially detect hidden cancers that might be missed by usual care, leading to earlier diagnosis and treatment. By combining this advanced imaging with regular screening protocols, there's hope for improving outcomes for stroke patients who may have underlying cancers.

What evidence suggests that this trial's screening methods could be effective for detecting occult cancer after stroke?

This trial will compare two approaches: Usual Care and Intensive Cancer Screening using FDG PET/CT. Studies have shown that FDG PET/CT scans can detect hidden cancers, particularly in patients who have experienced a stroke with no clear cause. Research indicates that this imaging method is more accurate than other tests for certain cancer types. It primarily assesses cancer spread and aids doctors in planning treatment. Initial findings suggest that FDG PET/CT might diagnose more hidden cancer cases in stroke patients, making it a valuable tool for identifying cancers that might otherwise remain undetected. ^{6 7 8 9 10}

Who Is on the Research Team?

Dariush Dowlatshahi, MD PhD

Principal Investigator

Ottawa Hospital Research Institute

Are You a Good Fit for This Trial?

This trial is for adults over 18 who've had a cryptogenic ischemic stroke, as defined by American Heart Association guidelines, and are able to consent. They must be seen at the Ottawa Hospital Stroke Prevention Clinic or Neurovascular Unit within 3 months of their stroke. Pregnant individuals or those with active/previous cancers (except certain skin cancers) can't participate.

Inclusion Criteria

Patient or delegate willing and able to provide informed consent.

Exclusion Criteria

I have or had cancer, excluding minor skin cancers.

I am not pregnant and can lie still for 20 minutes.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

12 months

Intensive Cancer Screening

Participants undergo FDG PET/CT in addition to usual care to detect occult cancers

24 months

Follow-up

Participants are monitored for safety and effectiveness after screening

24 months

What Are the Treatments Tested in This Trial?

Interventions

• FDG PET/CT
• Usual Care

Trial Overview

The INCOGNITO Pilot Trial is testing if adding FDG PET/CT scans to usual care helps find more hidden cancers in patients who have had an unexplained stroke compared to just usual care. It's a small-scale study designed to see if a larger one would be feasible.

How Is the Trial Designed?

Group I: Usual Care Experimental Treatment 1 Intervention

Cancer screening according to sex, age and risk as per Canadian Task Force on Preventative Health Care)

Group II: Intensive Cancer Screening Experimental Treatment 1 Intervention

Usual care plus FDG PET/CT

Who Is Running the Clinical Trial?

Ottawa Hospital Research Institute

Lead Sponsor

Trials

585

Recruited

3,283,000+

Canadian Stroke Consortium (CSC)

Collaborator

Trials

4

Recruited

2,500+

Brain Canada

Collaborator

Trials

22

Recruited

6,100+

Heart and Stroke Foundation of Canada

Collaborator

Trials

131

Recruited

72,600+

Published Research Related to This Trial

In a study of 85,893 stroke patients in Denmark, the prevalence of previously unknown cancer (occult cancer) was significantly higher in stroke patients compared to the general population, with rates of 25.0 per 1000 in women and 29.8 per 1000 in men.

Stroke patients have a 54% higher risk of developing occult cancer, with increased risk factors including age, male sex, smoking, and diabetes, highlighting the need for cancer screening in stroke patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Prevalence and risk of occult cancer in stroke. Tybjerg, AJ., Skyhøj Olsen, T., Andersen, KK.[2020]

In a study of nearly 86,000 stroke patients in Denmark, only 1 in 2000 with ischaemic strokes were found to have occult primary brain cancer, indicating a low risk of misdiagnosis and maltreatment in these cases.

However, among patients with haemorrhagic strokes, the occurrence of occult primary brain cancer was significantly higher at 1 in 66, suggesting that these cases should be carefully evaluated to avoid misdiagnosis.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Occult primary brain cancers manifesting in the aftermath of ischaemic and haemorrhagic stroke. Andersen, KK., Tybjerg, AJ., Babore, AD., et al.[2022]

In a study of 134 cancer patients, those who experienced ischaemic strokes had significantly higher target-to-background ratios (TBRs) in their carotid arteries and abdominal aorta, indicating increased arterial inflammation.

The proportion of visceral adipose tissue (VAT) and total adipose tissue (TAT) were also higher in stroke patients, suggesting that these imaging biomarkers, along with FDG uptake, could help predict future strokes in cancer patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

18F-FDG PET/CT imaging factors that predict ischaemic stroke in cancer patients. Kim, J., Choi, KH., Song, HC., et al.[2018]

Positron emission tomography (PET) can be useful in detecting strokes incidentally during oncological imaging, as shown by focal uptakes of 11C-Choline and 68Ga-DOTATATE in areas of confirmed ischemia.

In some cases, increased 18F-FDG activity was observed around hemorrhagic regions, suggesting that PET can provide valuable insights into the flow dynamics and metabolic activity associated with stroke.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stroke detection with 3 different PET tracers. Dundar, A., Bold, MS., Agac, B., et al.[2020]

In the first year following a new cancer diagnosis, the overall incidence of stroke is estimated at 1.4%, with ischemic strokes being more common (1.3%) compared to spontaneous intracerebral hemorrhages (0.3%).

This systematic review analyzed data from 41 studies involving over 2.5 million cancer patients, highlighting the need for education on stroke risk and the development of prevention strategies for this vulnerable population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Incidence of stroke in the first year after diagnosis of cancer-A systematic review and meta-analysis. Lun, R., Roy, DC., Hao, Y., et al.[2022]

Patients with a new diagnosis of cancer have an increased risk of ischemic stroke, with about 6% of those experiencing cryptogenic ischemic stroke being diagnosed with cancer within a year, indicating that stroke may be an early sign of undiagnosed cancer.

This scoping review aims to identify and evaluate screening strategies for occult cancer in individuals with ischemic stroke, which could help inform future clinical trials and improve early cancer detection in this high-risk population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A scoping review protocol on diagnostic strategies to detect occult malignancies in individuals with ischemic stroke. Leentjens, J., Chornenki, NLJ., Spiegelenberg, J., et al.[2023]

In a study of 85,893 stroke patients in Denmark, it was found that those who had a stroke had a significantly higher prevalence of smoking-related occult cancers, such as lung and colon cancer, compared to the general population (13.3 vs 8.1 per 1000 person-years).

The study indicated that while stroke patients are at increased risk for certain cancers, particularly smoking-related ones, there was no significant increase in the risk for common cancers not related to smoking, like prostate and breast cancers.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Types of occult cancer in stroke and the relation to smoking. Tybjerg, AJ., Babore, AD., Olsen, TS., et al.[2021]

Clinically occult thyroid cancer is relatively common, affecting 1% to 10% of the population, and can be detected using fluorodeoxyglucose positron emission tomography (FDG PET).

In a small case series, FDG PET successfully identified coincident primary tumors in 2 out of 4 patients with head and neck cancer, suggesting that this imaging technique may improve detection rates and potentially influence treatment outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Fluorodeoxyglucose positron emission tomography, a new technique for increasing the detection rate of coincident thyroid cancer in head and neck oncology. Stokkel, MP., de Klerk, JM., Hordijk, GJ.[2019]

The pooled incidence of cancer within one year after an ischemic stroke is 13.6 per thousand, with a notably higher rate of 62.0 per thousand in cases of cryptogenic stroke, indicating that certain types of strokes may warrant more vigilant cancer screening.

Predictors such as older age, smoking, and elevated inflammatory markers like C-reactive protein and d-dimers can help identify patients at higher risk for developing cancer after a stroke, suggesting that targeted screening could be beneficial.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Frequency and predictors of occult cancer in ischemic stroke: A systematic review and meta-analysis. Rioux, B., Touma, L., Nehme, A., et al.[2021]

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