Low-risk prostate cancer patients may not benefit from high-dose radiation, a new review found. Findings showed that high dose radiation in these patients do not result in higher rates for survival or lower rates of cancer spreading to other body parts.
There is often an assumption that to effectively kill cancer, patients can be given the highest dose of radiation their bodies can tolerate, researcher Dr. Robert Den explained about the radiation oncology field. The new review findings were in contradiction with the notion, at least among patients with low-risk prostate cancer.
In the review, a team from the Thomas Jefferson University's cancer center analyzed 12 studies dating back to 1990 that investigated the use of external-beam radiation therapy (EBRT) to treat over 6,800 male patients with localized prostate cancer.
The prostate-specific antigen (PSA) levels are used to monitor cancer. When patients received high-dose radiation, their PSA levels dropped. However, a higher dosage did not lead in increasing the patients' long-term survival rates or lowering cancer's spread to other body parts.
"This study suggests that our reliance on the PSA test as a proxy for patient outcomes may not as useful as many researchers thought," said Adam Dicker, the university's medical college radiation oncology chair.
The new review contradicted a 2015 study wherein another team of researchers found that escalated EBRT was associated with increased survival rates. But the effect may have benefitted the male patients with a more advanced form of the disease.
The current team acknowledged the lack of individual patient information such as their cancer characteristics and quality of life that could have had effects on how their individual cancers progressed. The researchers also did not know if the male patients involved in the review experienced two chronic conditions or diseases simultaneously.
But in terms of giving high-dose radiation to low-risk patients, the researchers suggested keeping assumptions in check. The findings can be useful in designing clinical trials in the future and in interpreting both past and current studies of high-dose radiation cancer treatments.
The new review was published in the American Journal of Clinical Oncology.