Most tests used by doctors to diagnose cancer, such as mammography, colonoscopy and computed tomography (called CT) are based on imaging. More recently, researchers have also developed molecular diagnostics capable of detecting specific molecules associated with cancer that circulate in body fluids such as blood or urine. MIT engineers created a new diagnostic technique that combines these two characteristics: it can reveal the presence of cancerous proteins through a urine test and works as an imaging agent, locating the location of the tumor.
In principle, this diagnosis could be used to detect cancer anywhere in the body, including tumors that have metastasized from their original location. A metastasis is in fact a tumor formed from cancer cells which have detached themselves from a first tumor and which have migrated to another part of the body where they have settled. It is not another cancer, but the original cancer that has spread. “This is a very large sensor intended to respond to both primary tumors and their metastases. It can trigger a urinary signal and also allow us to visualize where the tumors are. “, Explain the researchers.
Detecting a cancerous tumor with urine
In their study published in the journal “Nature Materials” they showed that this type of diagnosis could be used to monitor the colon cancer progression, including the spread of metastatic tumors to the lungs and liver. They hope that eventually it could act as a routine test that could be done every year. Their technique is based on the principle of synthetic biomarkers which can be easily detected in urine, since most cancer cells express enzymes called “proteases”. The nanoparticles developed by the researchers, to be ingested, can “attach” to these proteases, making them cancer “markers”.
Concretely, when these particles encounter a tumor in the body, they are excreted in the urine where they can be easily detected by doctors. In animal models of lung cancer, this process allowed early detection of the presence of tumors. However, researchers were faced with the fact that it cannot reveal the exact location of the tumor or whether it has spread beyond its original organ. They therefore wanted to develop a “multimodal” diagnosis, which can perform both molecular screening (urine signal detection) and imaging, to tell exactly where the original tumor and metastases are.
A routine screening test that is easy to set up
To modify the particles so that they can also be used for imaging, the researchers have added a radioactive tracer. This new process has been tested in two mouse models of metastatic colon cancer, in which tumor cells grow in the liver or lungs. After treatment with a chemotherapy drug commonly used to treat colon cancer, scientists were able to use both the urinary signal and the imaging agent to successfully monitor the response of tumors to treatment. this type of diagnosis could therefore prove useful for early detection and to assess patient response to treatment.
Although the study is currently only conducted in mice, the researchers hope that this type of diagnosis will also be used to monitor patient remission. “These patients could be followed with the urine version of the test every six months. If the test is positive, the radioactive version could be followed up for an imaging study that could indicate where the disease has spread. The two test modes using a single formulation. Every year you could take a urine test as part of a general health check-up. », Notes the scientific team. This diagnosis would be intended in particular for patients who cannot have access to a screening infrastructure that they consider too expensive.