Analytical and clinical validation of a circulating tumor DNA-based assay for multi-cancer early detection
Authors: Dang Nguyen Luu Hong , Hanh Nguyen Thi Hue , Le Van Hoi , Bui Vinh Quang , Nguyen Lan Hieu , Pham Nhu Hiep , Phan Thanh Hai , Nguyen Huu Thinh , Tran Van Song , Bui Chi Viet , Vo Van Kha , Nhan Nguyen Pham Thanh , Dang Ha Huu Phuoc , Pham Van Dung , Cao Van Thinh , Phan Ngoc Minh , Tieu Ba Linh , Huong Nguyen Giang Thi , Vo Dac Ho , Tran Trung Hieu , Nguyen Thanh Dat , Chi Nguyen Van Thien , Nguyen Trong Hieu , Tran Vu Uyen , Le Minh Phong , Thu Tran Thi Minh , Nguyen Minh Nguyen , Vi Van Thi Tuong , Nguyen Anh Nhu , Nguyen Thi Thanh , Tan Doan Nhu Nhat , Nguyen Hoang Tan , Doan Phuoc Loc , Khoa Huynh Le Anh , Nguyen Tien Anh , Phuc Nguyen Huu Tam , Lu Y-Thanh , Tien Cao Chi Thuy , Nguyen Van Tung , Quyen Le Thi Le , Luong Thi Lan-Anh , Phuong Doan Thi Kim , Dao Thi Trang , Phan Canh Duy , Nguyen Thanh Xuan , Pham Nguyen Tuong , Nguyen Bao Toan , Thuy Pham Thi Thu , Le Huu Linh , Truong Cong Thanh , Jasmine Thanh Xuan , Le Minh Chi , Phan Van Bau , Truong Quang Binh , Ly Tran Thi Huong , Huynh Minh Thien , Tran Tu Quy , Nguyen Si Tuan , Tran Vu , Tran Van Khanh , Nguyen Huu Nguyen , Nguyen Duy Sinh , Phan Thi Van , Do Thi Thanh-Thuy , Truong Dinh Kiet , Tang Hung Sang , Giang Hoa , Nguyen Hoai-Nghia , Phan Minh-Duy , Tran Le Son 
Published: December 2023

Background

The emergence of multi-cancer early detection (MCED) via a single blood test offers promise in enhancing the efficiency of early cancer detection and improving population health. However, the lack of analytical validation and clinical evidence across diverse populations has hindered their adoption in clinical practice. To address these challenges, we undertook a comprehensive analytical and clinical validation for our MCED test, SPOT-MAS (Screening for the Presence Of Tumor by DNA Methylation And Size).

Methods

The analytical validation was conducted on a retrospective cohort of 290 healthy and 461 cancer-confirmed individuals to establish the limit of detection, repeatability and reproducibility of test results and assess the impact of potential interferents on test performance. To validate the performance of SPOT-MAS test in clinical settings, we launched a multi-center prospective trial, named K-DETEK, of 9,057 asymptomatic participants in Vietnam.

Findings

For analytical validation, SPOT-MAS could detect at least 50% of cancer samples at a specificity of 98% if the samples have tumor fraction 0.049 (95% CI: 0.043-0.059). The results were consistently reproduced for both intra- and inter-batch analysis. Moreover, our test remained robust at hemoglobin contamination of 500 mg/dl and genomic DNA contamination of up to 100%. In the clinical trial, our assay achieved a positive predictive value of 58.14% (95%CI: 43.33-71.62) with 84.00% (95%CI: 65.35-93.60) accuracy in predicting tumor location, a negative predictive value of 99.92% (95%CI: 99.84-99.96), an overall sensitivity of 78.13% (95% CI: 61.25-88.98) and a specificity of 99.80% (95% CI: 99.68-99.87).

Interpretation

To our knowledge, this is the first and largest prospective validation study in Asia supporting the utility of SPOT-MAS as a multi-cancer blood test for early detection in a limited-resource country, where a nationwide cancer screening program is urgently needed but currently not available.

Funding

Gene Solutions