Nguyen LHD, Nguyen THH, Le VH, Bui VQ, Nguyen LH, Pham NH, Phan TH, Nguyen HT, Tran VS, Bui CV, Vo VK, Nguyen PTN, Dang HHP, Pham VD, Cao VT, Phan NM, Tieu BL, Nguyen GTH, Vo DH, Tran TH, Nguyen TD, Nguyen VTC, Nguyen TH, Tran VU, Le MP, Tran TMT, Nguyen Nguyen M, Van TTV, Nguyen AN, Nguyen TT, Doan NNT, Nguyen HT, Doan PL, Huynh LAK, Nguyen TA, Nguyen HTP, Lu YT, Cao CTT, Nguyen VT, Le Quyen Le T, Luong TL, Doan TKP, Dao TT, Phan CD, Nguyen TX, Pham NT, Nguyen BT, Pham TTT, Le HL, Truong CT, Jasmine TX, Le MC, Phan VB, Truong QB, Tran THL, Huynh MT, Tran TQ, Nguyen ST, Tran V, Tran VK, Nguyen Nguyen H, Nguyen DS, Van Phan T, Do TT, Truong DK, Tang HS, Giang H, Nguyen HN, Phan MD, and Tran LS
Background: Non-invasive multi-cancer early detection (MCED) tests have shown promise in enhancing early cancer detection. However, their clinical utility across diverse populations remains underexplored, limiting their routine implementation. This study aims to validate the clinical utility of a multimodal non-invasive circulating tumor DNA (ctDNA)-based MCED test, SPOT-MAS (Screening for the Presence Of Tumor by DNA Methylation And Size)., Methods: We conducted a multicenter prospective study, K-DETEK (ClinicalTrials.gov identifier: NCT05227261), involving 9057 asymptomatic individuals aged 40 years or older across 75 major hospitals and one research institute in Vietnam. Participants were followed for 12 months., Results: Of the 9024 eligible participants, 43 (0.48%) tested positive for ctDNA. Among these, 17 were confirmed with malignant lesions in various primary organs through standard-of-care (SOC) imaging and biopsy, with 9 cases matching our tissue of origin (TOO) predictions. This resulted in a positive predictive value of 39.53% (95%CI 26.37-54.42) and a TOO accuracy of 52.94% (95%CI 30.96-73.83). Among the 8981 participants (99.52%) who tested negative, 8974 were confirmed cancer-free during a 12-month period after testing, yielding a negative predictive value of 99.92% (95% CI 99.84-99.96). The test demonstrated an overall sensitivity of 70.83% (95%CI 50.83-85.09) and a specificity of 99.71% (95% CI 99.58-99.80) for detecting various cancer types, including those without SOC screening options., Conclusions: This study presents a prospective validation of a multi-cancer early detection (MCED) test conducted in a lower middle-income country, demonstrating the potential of SPOT-MAS for early cancer detection. Our findings indicate that MCED tests could be valuable additions to national cancer screening programs, particularly in regions where such initiatives are currently limited., Trial Registration: ClinicalTrials.gov ID: NCT05227261. Date of registration: 07/02/2022., Competing Interests: Declarations. Ethics approval and consent to participate: This research received approval from the Ethics Committee of the University of Medicine and Pharmacy, Ho Chi Minh City, Vietnam (approval number: 192/HĐĐĐ-ĐHYD). Each participant provided written informed consent, adhering to the Declaration of Helsinki. Consent for publication: Not applicable. Competing interests: The authors including LST, HNN, HG, MDP, HHN and DSN hold equity in Gene Solutions. NHN, HG, MDP and LST are inventors on the patent application (USPTO 17930705). LHDN, THHN, NMP, BLT, GTHN, DHV, THT, TDN, VTCN, THN, VUT, MPL, TMTT, MNN, TTVV, ANN, TTN, NNTD, HTN, PLD, LAKH, TAN, HTPN, YTL, CTTC, TVP, TTTD, DKT, and HST received salaries from the project funded by the Medical Genetics Institute, Ho Chi Minh City, Vietnam. We confirm that this does not alter our adherence to journal policies on sharing data and materials. VHL, VQB, LHN, NHP, THP, HTN, VST, CVB, VKV, PTNN, HHPD, VDP, VTC, BLT, TTN, HTPN, CTTC, VTN, TLQL, TLAL, TKPD, TTD, CDP, TXN, NTP, BTN, TTTP, HLL, CTT, TXJ, MCL, VBP, QBT, THLT, MTH, TQT, STN, VT, VKT declare that they have no competing interests. VHL, VQB, LHN, NHP, THP, HTN, VST, CVB, VKV, PTNN, HHPD, VDP, VTC, BLT, TTN, HTPN, CTTC, VTN, TLQL, TLAL, TKPD, TTD, CDP, TXN, NTP, BTN, TTTP, HLL, CTT, TXJ, MCL, VBP, QBT, THLT, MTH, TQT, STN, VT, and VKT declare that they have no competing interests., (© 2025. The Author(s).)