While blood tests for some types of cancer indicate if malignant cells remain after treatment, this has not been the case with soft tissue sarcomas and many other solid tumors.
More accurate ways are needed to detect sarcomas before the cancer is large enough to show up on imaging. Instead of relying on scans and a physical exam to see if a patient’s sarcoma returns, the current standard of care, doctors want to be able to tell patients sooner, "You are cancer-free.”
If cancer is still present, detecting it earlier may allow more prompt intervention in hopes of preventing the progression of disease.
Testing for genetic material
In a clinical trial, researchers are evaluating if the presence and levels of circulating tumor DNA (ctDNA) in a sarcoma patient’s blood can provide information about the success of the individual’s treatment.
Other studies have looked at the presence of ctDNA in patients with pancreatic cancer and lung cancer. Those studies showed that if ctDNA was present in the blood following treatment, the patient prognosis was worse.
New data on sarcomas
Developing a blood test for soft tissue sarcomas is particularly complex because there are more than 50 subtypes of the disease and countless mutations possible.
Each sarcoma responds to therapies very differently. Two people may have the same subtype of sarcoma, but because their mutations may be different, they could need two different treatments. Because there are many subtypes of this rare cancer, little data exists, which is why more sarcoma research is needed.
In a clinical trial enrolling two groups of patients, the first group will have localized disease. The second group will have stage IV disease. The investigative team will test for ctDNA in the blood of both groups before treatment and at regular intervals afterward.
Researchers are optimistic that using ctDNA will eventually be a game changer for sarcoma patients across the country. By detecting sarcoma in the blood sooner than is currently possible using imaging, they are hopeful they can improve survival rates.
