Multi-year clinical outcomes of cancers diagnosed following detection by a blood-based multi-cancer early detection (MCED) test.

In the U.S., <20% of cancers are diagnosed by standard-of-care (SoC) screening. Multi-cancer early detection (MCED) tests offer the opportunity to expand cancer screening. Understanding the characteristics and clinical outcomes of MCED-detected cancers is critical to clarifying MCED tests' potential impact. DETECT-A is the first prospective interventional trial of an MCED blood test (CancerSEEK). CancerSEEK, coupled with diagnostic PET-CT, identified cancers including those not detected by SoC screening, the majority of which were localized or regional. We report multi-year outcomes in patients with cancers diagnosed following a positive CancerSEEK test. Nine cancer types were diagnosed in 26 participants whose cancers were first detected by CancerSEEK. Information on cancer diagnoses, treatments, and clinical outcomes was extracted from medical records through November 2022. Data collection occurred a median of 4.4 years (IQR: 4.1-4.6) following study enrollment. Thirteen of 26 (50%) participants were alive and cancer-free [ovarian (4), thyroid (1), uterine (2), breast (1), colorectal (2), and lung (3)]; 7/13 (54%) had cancers without recommended SoC screening modalities. All 8 treated stage I or II participants (8/8, 100%) and 12/14 (86%) surgically-treated participants were alive and cancer-free. Eligibility for surgical treatment was associated with favorable multi-year outcomes (p = 0.0002). Half of participants with MCED-detected cancers were alive and cancer-free after 4.4 years median follow-up. Most were diagnosed with early-stage cancers and were treated surgically. These results suggest that early cancer detection by CancerSEEK may have facilitated curative-intent treatments and associated positive clinical outcomes in some DETECT-A participants.