Based on retrospective analysis of 2,132 prostate cancer patients in their single-institution database, researchers from the Fox Chase Cancer Center have reported that patients receiving radiation as first-line treatment for localized prostate cancer and who have a rising PSA within 18 months are at a significantly increased risk of death from prostate cancer compared to those whose PSA starts to rise after > 18 months.
While there is a certain degree of “obviousness” to this report, what is interesting is that this study may help us to make better decisions about when and how to treatment men with a rising PSA after first-line radiation therapy. In this study by Buyyounouski and his colleagues, reported yesterday at the annual meeting of the American Society for Radiation Oncology (ASTRO), the median time from treatment to biochemical failure was 35.2 months, but 19 percent of patients developed biochemical failure at 18 months or less. (Biochemical failure was defined by the Phoenix criterion of a PSA value increasing to > 2 ng/ml above the nadir, post-irradiation PSA level.)
Buyyounouski and his colleagues demonstrated that, in their patient series, the 5-year, cancer-specific survival for patients who developed biochemical failure within 18 months was 69.5 percent, compared with 89.8 percent for those who developed biochemical failure > 18 months after treatment.
“We haven’t known if having PSA rise sooner means a patient has a greater danger of dying of prostate cancer, though it seems logical,” said Buyyounouski. “Now we can use the simple criteria from this study, which is widely available for anyone who has PSA testing, to identify men who have a greater than 25 percent chance of dying from prostate cancer in the next 5 years. That is huge. There is nothing else that can do that.”
There are no absolute standards for the treatment of men with a rising PSA following first-line radiation therapy, although it is generally considered that the patient’s PSA doubling time is a strong indicator for risk of progression. Biochemical failure alone doesn’t always prompt treatment. According to Buyyounouski, the data from this study suggest that second-line treatment can and should begin as soon as biochemical failure occurs in men who experience such failure within 18 months of their initial radiation, “without waiting for other signs or symptoms of prostate cancer.”
Other factors may have to play into these decisions, however, because the patient’s age, comorbidities, and non-cancer life expectancy may also be relevant to the best course of action, but these data do seem to suggest that, for otherwise healthy men with a life expectancy of at least 5 years, the early application of second-line therapy will impact prostate cancer-specific survival. The appropriate type of second-line therapy may be a more difficult decision to reach for each individual patient.
For additional commentary on this study, please see reports on Science Daily and HealthDay.
Filed under: Management, Treatment Tagged: | biochemical failure, PSA, radiation
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