Daijiworld Media Network - New York

New York, Mar 23: Despite appearing successful on scans, radiotherapy may leave behind undetected microscopic cancer cells, posing a greater risk of recurrence and worse long-term outcomes than previously thought, researchers have warned.

Dr. Muzamil Arshad from the University of Chicago Medical Center and his team have raised concerns in an editorial published in the journal Oncotarget, urging a reassessment of how cancer treatment success is measured and how patients are monitored post-therapy.

Radiotherapy, particularly stereotactic ablative radiotherapy (SABR), is a widely used treatment for cancers in the lung, liver, prostate, and other organs. While SABR delivers high-dose radiation with remarkable precision, its effectiveness may not always be accurately reflected in imaging results.

Despite showing a clear response on scans, follow-up biopsies often uncover remaining cancer cells that imaging tests fail to detect. According to the researchers, residual cancer is found in 40% of lung cancer cases, 57–69% of renal cell carcinoma cases, 7.7–47.6% of prostate cancer cases, and up to 86.7% of hepatocellular carcinoma cases.

This discrepancy between scan results and actual tissue analysis could have significant consequences. Studies indicate that patients with even a small amount of residual disease face a higher likelihood of cancer recurrence and reduced survival rates. The trend has been observed across multiple cancer types, including rectal, cervical, prostate, and liver cancers. In some cases, incomplete eradication of a tumor may even contribute to its spread to other organs.

The researchers emphasized that a ‘complete response’ on imaging does not always mean the cancer has been entirely eliminated. They urged the medical community to adopt a more comprehensive approach to evaluating treatment outcomes, recognizing the hidden threat of residual disease to improve long-term survival rates.