As clinicians, we deal with this issue all the time. It is all about the trust between a clinician and clinician, and also the client and the clinician.
Western herbs such as St John's Wart is found to increase P450 (key enzymes for cancer formation) and also reduce chemotherapy results. Vitamin E and other antioxidants can reduce radiation therapy result. Cancer cells love to be boosted by abundant vitamins. Thus, any traditional oncologists will not recommend any supplements for any cancers.
However, Chinese herbal medicine treats a pattern. They are not antioxidants or vitamin supplements. They work on the whole body to balance the healing processing and also immune system. In general, I always recommend herbals for any cancer patients. Wei Qi Booster and/or Stasis Breaker have zero problems with chemotherapy and/or radiation therapy. I use them very often on canines being treated with chemotherapy.