A recent study conducted at Hospital de Amor de Barretos in Brazil has demonstrated that liquid biopsies can help identify genetic mutations in patients with non-small cell lung cancer (NSCLC), potentially expediting diagnosis and informing treatment strategies. The research, supported by FAPESP and published in the journal Molecular Oncology, evaluated blood samples from 30 patients, including those who had not received prior treatment as well as participants in a lung cancer screening program.
NSCLC is the most common type of lung cancer, accounting for about 85% of cases. Within this category, adenocarcinoma is notable for having mutations that can be targeted with specific therapies. In recent years, these advances have extended survival rates for some patients from less than eight months to as much as ten years.
Researchers analyzed 32 plasma samples using a commercial multigene panel focused on known mutations associated with adenocarcinoma. Mutations were detected in 65.6% of all samples and in 87.5% of samples from previously treated patients. The most frequently observed mutations involved the TP53 (40.6%), KRAS (28.1%), and EGFR (12.5%) genes.
Some of these genetic changes are actionable; for example, certain EGFR mutations can be addressed with approved drugs in Brazil, while a specific KRAS mutation (p.G12C) also has available treatments. However, there are currently no targeted therapies for TP53 mutations.
One notable case within the study was an asymptomatic participant who was found to have a TP53 gene mutation six months before receiving a cancer diagnosis, highlighting the potential use of liquid biopsies as a complementary screening tool for high-risk groups such as smokers and former smokers.
The researchers emphasize that time is critical when treating lung cancer. Traditional tissue biopsies require weeks due to scheduling and processing times, whereas liquid biopsy results can be available within two days after sample collection. "Time is a crucial factor when it comes to lung cancer," said Leal, one of the researchers involved in the study. "When we perform a tissue biopsy, we need to consider how long the patient waited to schedule the biopsy or surgery... With liquid biopsy, we can collect the sample at any time, and the results can be available in two days, allowing treatment to begin sooner."
Additionally, the study found that ctDNA could be detected even in frozen samples without special storage requirements or immediate transport needs—a feature that could facilitate broader adoption by public health services lacking advanced laboratory infrastructure.
Despite these advantages, economic barriers remain significant for widespread implementation within Brazil's public health system (SUS). The test used costs around BRL 6,000 (approximately USD 1,110) per patient—an amount out of reach for many Brazilians—while some targeted therapies cost up to BRL 40,000 (USD 7,400) per month.
In private healthcare settings regulated by Brazil’s National Supplementary Health Agency (ANS), more options exist for both testing and therapy; however, access remains limited within SUS referral centers.
Leal cautioned that although their chosen panel was highly sensitive—up to ten times more so than some tissue-based tests—a negative result does not definitively rule out genetic alterations: "If the liquid biopsy doesn't detect any changes, it's necessary to confirm with the tissue. We still can't completely replace the conventional biopsy; these are complementary tests." This limitation is especially relevant during early disease stages when ctDNA levels may be low.
The study concludes that integrating liquid biopsies into clinical practice could accelerate diagnoses and improve personalized care for Brazilian lung cancer patients across different stages of disease progression: "Our work shows that it's possible to detect several mutations at the same time, reduce response time, and use samples that don't require special collection," summarized Leal. "This can accelerate the start of treatment and improve patient outcomes." The researchers anticipate increased access to personalized medicine as sequencing costs decrease and testing becomes more widely available.
