NEW YORK, Oct 19 (Reuters Health) -- Prostate cancer patients treated with radiation therapy are highly likely to be cured if they do not experience fluctuations in levels of prostate-specific antigen -- PSA, a marker of prostate health -- for 5 years following treatment, report US researchers.
"The results provide a practical guide to advise patients when or whether they can be considered cured of their malignancy," explain Dr. Larry L. Kestin and colleagues, from William Beaumont Hospital in Royal Oak, Michigan. They published their findings in the October 15th issue of the journal Cancer.
Prostate cancer remains the leading cancer killer of men after lung cancer, killing over 37,000 American men each year. Radiation, surgery, or hormone therapies are used to treat prostate cancer.
In their study, Kestin's team reviewed the records of 871 patients with localized prostate cancer treated with radiation therapy. The subjects had regular PSA tests for 5 years after the end of therapy. High blood levels of PSA are used as a 'marker' for the possible presence of prostate cancer.
The authors report that men whose PSA levels dropped to a stable low of 0.4 nanograms per milliliter of blood (ng/mL) within less than 2 years after surgery had "a very high probability of cure."
Patients who did not meet this ideal "may require longer follow-up than those with less favorable characteristics to achieve the same certainty of cure," the researchers said.
Kestin's group caution that their study focused on patients receiving one form of therapy -- radiation alone -- and they note that their results may not apply to patients receiving surgery or hormone therapies. Still, they believe that the findings may help physicians "determine more accurately the efficacy of a particular treatment" in the fight against prostate cancer.
