I forgot about vitamin E. it's said vitamin E, Beta Carotene can promote early cancers in the lungs, but that could be lung cancer, not sure about metastases from other areas. It's also said in some reports vitamin E can inpact survival in head and neck cancer when receiving radiation therapy, but like Maria said, not sure if any thought about antioxidants has changed, have seen some that said yes, but your doctors will know best.
It was thought tumors thrive in highly oxygenated areas, I guess in tumor surgery oxgen pressure matters, but they now say tumors thrive in hypoxic tissue when the tumor spreads, angiogenesis. That's my question to my doctors with HBOT, and wonder if it's the old school thought or their thinking about blood supply to feed the tumor...more confusion lol.
Thanks for the links Mamacita.
Here is information on ORN, to help you as a guide through the process to discuss with your doctors.
http://emedicine.medscape.com/article/851539-overview