There are certain genetic abnormalities that interfere with the normal DNA-repair mechanisms that healthy cells must have to self-repair after radiation exposure. The most common is a mutation of the ATM gene. Thankfully, it is very rare, and it is only fatal after radiation exposure if a person has 2 defective copies. People with it are often more sensitive to light and sunburn too. But some people are radiosensitive without it, and it is difficult to identify the genetic mutations that may lead to it.
There is another reason why it is of concern. The incidence of such genetic mutations is higher in men with prostate cancer and especially in men with metastatic prostate cancer. So you may be more prone to cancer, including other kinds of cancer. Paradoxically, the same genetic abnormality that makes healthy cells too easy to kill with radiation may cause cancer cells to be immortal. There is a new class of medicines called PARP inhibitors that may induce self-destruction (apoptosis) in such cancer cells. They also make cells more sensitive to radiation damage.
You could get some very expensive genetic testing to determine if you have a known genetic mutation that might have caused it. But the question is - what could you do about
it? There is a drug called amifostine that protects cells from radiation damage, but it is toxic and expensive, and since you will avoid radiation in the future, it is unnecessary. I guess the only thing you can do is to be alert
to symptoms of other cancers.
Allen - not an MD
•PSA=7.3, prostate volume=55cc, 8/17 cores G6 5-35% involvement
•SBRT 9 yr onc. results
•SBRT 7 yr QOL results
•treated 10/2010 at age 57 at UCLA,PSA now: 0.1,no lasting urinary, rectal or sexual SEsmy PC blog