Residual cancer worsens long-term outcomes after SABR treatment

Radiotherapy is commonly used to treat cancers affecting the lung, liver, prostate, and other organs. A specific method called stereotactic ablative radiotherapy (SABR) is known for delivering high doses of radiation with great precision. While SABR usually shows good results on scans, new research raises concerns about what those scans may miss. Researchers from the University of Chicago Medical Center have found that microscopic cancer can remain after treatment, even when scans suggest the tumor is gone. This "residual disease" seems to be more common than previously thought and is associated with worse long-term health outcomes. In their editorial published in the journal Oncotarget, the researchers argue that doctors should reconsider how they measure the success of cancer treatments. They note that many patients may still have cancer cells that are not detected in imaging tests, which can lead to complications later. According to their findings, around 40% of lung cancer patients and up to 69% of renal cell cancer patients may still have residual disease. The numbers are lower for prostate and liver cancers, but the issue persists across various types of cancer. The presence of residual cancer increases the likelihood of recurrence and can shorten patient survival. The researchers emphasize the importance of further testing, like follow-up biopsies, to uncover any hidden cancer. They suggest that relying solely on imaging may provide a false sense of security. Recognizing and addressing this hidden threat is essential for improving outcomes for cancer patients.