Studies show that both the incidence of cancer and mortality rates in Vietnam have tripled over the past 3 decades; in 2020, over 182,560 new cases of cancer were diagnosed in the country, and nearly 123,000 people died from the disease. In addition, most cases—up to 80%—are diagnosed at an advanced stage (stage III or IV), leading to a low 5-year survival rate.
A Vietnamese prospective study by Nguyen et al investigating the feasibility and performance of a circulating tumor DNA (ctDNA)-analyzing test in the early detection of the five most common cancer types in Vietnam—liver, breast, colorectal, gastric, and lung cancers—found that the test was successful in detecting cancers in asymptomatic individuals with a positive predictive value of 60%. In addition, the test had nearly 84% accuracy in detecting tumor location. The study will be presented during the 2023 ASCO Breakthrough meeting, taking place August 3 to 5 in Yokohama, Japan (Abstract 135).
Study Methodology
The researchers launched a prospective cohort study, K-DETEK (ClinicalTrials.gov identifier NCT05227261) in 13 major hospitals and 1 research institute in Vietnam to validate their previously developed multimodal liquid biopsy–based assay, Screening for the Presence of Tumor by Methylation and Size (SPOT-MAS). The ctDNA-analyzing test is used for the detection of early-stage disease in the five most common cancers among high-risk or asymptomatic individuals, including liver, breast, colorectal, gastric, and lung cancers.
The study recruited 10,000 asymptomatic participants aged 40 years and older and performed follow-up testing at 6 and 12 months. The performance of the ctDNA test was assessed by computing the number of cases with the detection of a signal, including a positive predictive value and accuracy in detecting tumor tissue-of-origin.
Results
At the time of the abstract submission, the researchers had analyzed blood samples from 2,795 participants. They found that the ctDNA test detected cancers in asymptomatic individuals with a positive predictive value of 60%, with 83.3% accuracy in detecting tumor location.
In addition, the researchers presented a case report to support further using SPOT-MAS as a complementary method to achieve early cancer detection and provide the opportunity for early treatment.
Clinical Significance
“Our study has demonstrated the clinical application of a multicancer test in a low- and middle-income country like Vietnam, where a nationwide cancer screening program is urgently needed, but currently not available. Beyond detecting cancer signals, our test predicted the tumor location, allowing clinicians to fast-track the follow-up diagnostic and guide any necessary treatment,” concluded the study authors.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.
