Outcomes Following a False-Positive Multi-Cancer Early Detection Test: Results from DETECT-A, the First Large,...

Area of Science:

• Oncology
• Medical Diagnostics
• Cancer Screening

Background:

• Standard of care (SoC) cancer screening covers only four cancer types, missing many cancer-related deaths.
• Multi-cancer early detection (MCED) blood tests offer potential for broader cancer screening.
• Long-term outcomes for individuals with false positive (FP) MCED results require evaluation.

Purpose of the Study:

• To assess the performance of an imaging-based diagnostic workflow following a positive MCED blood test (CancerSEEK) with no initial cancer diagnosis.
• To evaluate the long-term cancer risk in participants with false positive (FP) MCED results.
• To analyze clinical outcomes and cancer incidence in a cohort with FP results from the DETECT-A trial.

Main Methods:

• Prospective analysis of 98 DETECT-A participants with a positive CancerSEEK test and negative 18-F-FDG PET-CT/contrast-enhanced CT imaging within one year.
• Medical record review, study interactions, and surveys to track cancer incidence, treatments, and outcomes through August 2023.
• Median follow-up of 3.6 years from determination of FP status.

Main Results:

• 95 out of 98 participants (96.9%) with FP results remained cancer-free.
• Three incident cancers (one ovarian, two breast) were diagnosed during the follow-up period.
• The annual incidence rate of cancer post-FP determination was 1.0% (95% CI: 0.2%-2.8%).

Conclusions:

• Participants with a positive MCED test (CancerSEEK) and negative imaging workup have a low risk of developing cancer in the subsequent years.
• The diagnostic workflow involving imaging after a positive MCED test is effective in identifying individuals without cancer.
• This study provides crucial long-term safety data for MCED blood testing in cancer screening.