Does radiation makes the tumor not responsive to chemo?

[Julie2]

Hi All,

I progressed on Navelbine,Tykerb,TDM1 and Xeloda. I have mets in lungs and a mammary node. I just started Gemzar and also looking into local targeted radiation. The radiation oncologist said all my tumors are amenable to radiation. He would like to do more conventional radiation to mammary node and Cyberknife to lungs, but the insurance approval is a big holdup.
My question is will the radiation makes the tumor not responsive to chemo later(in case if the same tumor progresses)? Or what other risks are involved in radiation or Cyberknife?

Thanks,
Julie

[Lani]

As I understand it, there is only the theoretical possibility that by radiating the tumor/mets you are selecting out the more quickly dividing cells (just like chemo) and leaving the dormant cancer stem cells.

That theoretical possibility apparently is the same with chemo or radiation as I understand it.

Theoretically again, the best combination with radiation therapy would be concurrent treatment with a targetted agent against the most common pathway it would "escape" from the treatment--whether something that targets cancer stem cells or otherwise.

That being said (ie, theoretically), nothing I have read has described radiation as making subsequent chemotherapy less likely to work, but it would be difficult to do a controlled experiment to test this out..

As with most things, it seems they do not know yet!

Sorry...

[Joan M]

Julie,

I'm sorry about your insurance difficulties. That's a problem in the U.S., unfortunately. Insurance companies telling doctors how to treat patients.

It's possible to remove the mammary node via surgery and perhaps the lung mets as well (with a wedge resection). I had a friend with one mammary node with cancer. First she was given chemo. The cancer went away, but then came back. Then the node was radiated. The cancer went away again, and then came back. Finally it was removed by surgery, and then never came back.

The lung mets might also be eradicated with radiofrequency ablation (RFA). That is, burned out. I had this done and the met never came back. Ask your onc about this, but when he says, no, go directly to an interventional radiologist for their opinion (but I'm glad he's thinking of other options, like Gamma Knife. As most oncs don't. So he sounds somewhat open minded). That doctor would be the one most able to tell you whether the procedure is possible in your case. I don't know where you live, but go to a major cancer center or a hospital with a large cancer unit. If you want, I could PM you on a top radiologist at a major cancer institute for feedback. You would be able to send him a CD of the scan.

If the mets could be removed it might lessen the tumor load and allow chemo could work better. I hope you're still taking Herceptin.

Joan

[hutchibk]

I too am sorry about your insurance difficulties. Beyond the problem of insurance companies telling doctors how to treat patients, the government/Medicare has told my rads onc twice in the last 3 years that he 'overtreated' for my radiated brain and skull mets and they only paid for about 1/3 of his bill. Bean counters telling doctors how to proceed is detestable. Hope your ins co moves swiftly on giving approval.