Rising PSA levels after radiation treatment can predict prostate cancer mortality

This article evaluated whether the interval to biochemical failure (IBF) can be used as a prediction factor for prostate cancer mortality. The IBF was found to be the best current predictor of prostate cancer mortality in patients previously treated with radiation therapy.

Biochemical failure is defined as a rise (of more than 2 ng/ml) of the PSA (prostate-specific antigen) level in the blood stream in prostate cancer (PC) patients after treatment with surgery or radiation. The IBF represents the time period between completion of treatment and the discovery of Biochemical failure.

Following treatment with radiation therapy for confined prostate cancer, PSA levels are regularly checked to see if they begin to rise. This may mean that the cancer has returned and should start quick interventions with further radiation treatments or androgen deprivation therapy (ADT or anti-male hormone therapy). Patients often want to know what the rising PSA levels mean and how this will affect their survival.

This study enrolled 1722 men who had been treated with radiation and were found to have biochemical failure. 17% of patients had an IBF within the first 18 months post-radiotherapy (≤ 18 months). The five-year survival rates (the percentage of patients who live at least 5 years after their cancer is diagnosed) were 73.7% in patients with an IBF ≤ 18 months and 90.6% with an IBF > 18 months. The ten-year estimated survival rates were 44.1% and 73.8%, respectively. This means that the earlier the rise in PSA occurs the worse the prognosis is.  

In summary, statistical analysis revealed that the IBF was a useful indicator, with a sensitivity to predict prostate cancer mortality within 10 years of almost 50%. These results highlight the value of considering the IBF when estimating the risk of prostate cancer mortality in patients previously treated with radiation therapy. It may also apply to men who were treated surgically. Such patients may benefit from a more aggressive and early interventions.

It should be noted however that the IBF is not the sole predictor of prostate cancer mortality and that risk estimates need to take into account many other factors. Treatments of rising PSA levels also have different response rates in various patients.