Biosensors can detect brain tumors with less than a drop of blood

According to the National Cancer Institute, despite significant progress, the death rate from brain tumors remains high, with a 5-year survival rate of 36 percent
.
A more accurate diagnosis may improve the situation, but tissue biopsies are invasive and may miss important information
about tumor composition.
At the same time, image-based methods do not provide sufficient sensitivity and resolution
.
Now, the researchers report in the journal ACS Nano that they have developed a biosensor that could help doctors accurately diagnose brain cancer
from a one-minute blood sample.

To effectively treat brain cancer, doctors need to confirm not only the presence of malignancies, but also where it originated (primary tumor) or metastasized from other organs to the brain (secondary tumor
).
Doctors also need to know where the tumor is
in the organ.
Because existing diagnostic techniques do not require surgery or painful spinal punctures to accomplish this feat, Bo Tan and his colleagues wanted to develop a noninvasive test
that uses a small amount of serum.

The researchers used a high-intensity laser beam to form a three-dimensional nickel-nickel oxide nanolayer
on a nickel chip.
This process produces an ultra-sensitive biosensor that allows them to detect trace amounts of tumor-derived substances, such as nucleic acids, proteins, and lipids, that pass through the blood-brain barrier and enter circulation
.
The sensor detects these components using a method called surface-enhanced Raman spectroscopy, which generates a molecular map or fingerprint
for each sample.
The researchers then analyzed the data with the DEEP neural network to find evidence of brain tumors, determine their type, and predict their location
in the brain.

Using a liquid biopsy platform, researchers can detect brain cancer from 5 microliters of serum and distinguish
it from breast, lung and coloral cancers with 100% specificity and sensitivity.
They had similar success
in distinguishing between primary brain tumors and secondary brain tumors that metastasized to the brain (metastases from the lungs or mammary glands to the brain).
The profile analysis also allowed the researchers to determine with 96 percent accuracy which of the nine brain regions the tumor was located
.
The non-invasive nature of this test should allow health care professionals to monitor the development of cancer over time so they can make better treatment decisions
, the researchers said.

DEEP Surveillance of Brain Cancer Using Self-Functionalized 3D Nanoprobes for Noninvasive Liquid Biopsy