Prostate Cancer Test 'Bounce' No Worry
Temporary Rise and Fall in PSA Levels After Radiation Does Not Affect Survival
Survival, Risk of Spread Not Affected
The researchers studied men who were treated with either external beam
radiation therapy or radiation seed implants.
In external beam radiation therapy, a beam of high-dose radiation is aimed
at the prostate to kill cancer cells.
In radiation seed implant therapy, or brachytherapy, surgeons implant tiny
radioactive seeds into the prostate gland. The seeds deliver high-dose
radiation directly to the prostate for a predetermined length of time.
Over the 10 years following treatment, 902 of the men in the study who were
treated with external beam radiation therapy and 470 of the men given seed
implants experienced a PSA bounce.
But the study showed no significant difference in success rates among
patients who had a bounce and those who did not. Among its findings:
- Of the men given external beam radiation therapy, 67.5% who had a bounce
were alive at 10 years vs. 64.5% of those who did not have a bounce. Cancer
recurrence was similar in both groups.
- Of patients given seed implants, 66.3% who had a bounce were alive at 10
years vs. 62.5% of those who did not have a bounce. Again, cancer recurrence
was comparable in the two groups.
The chance of cancer spreading elsewhere was also similar in both
Horwitz says the reason men with the seed implants fared better is they
tended to have earlier-stage cancer.
PSA Readings Every 3 Months
No one knows for sure why men treated with radiation experience a temporary
rise and fall in PSA levels, but Cole says most doctors believe it's associated
with the death of cancer cells.
"It's like when you throw water on a fire," he tells WebMD. "At
times there may be a whole lot of smoke and you think the fire is getting
worse. But eventually it calms down and the fire is out."
So what should you do if have a rise in your PSA level after radiation?
"You have to get a few readings over the next year," Horwitz says,
adding that most doctors recommend screening every three months or so.
"But try to relax and realize that it's OK, that this happens, and that
a bounce does not mean your cancer has recurred," he says.