Topic: chemo reduction of 20 percent

Hi all, I'm confused and wondering if anyone has had this experience...after three rounds of an Oxi/Gem combo, my mother is wiped out. She feels worse after each round so today her oncologist decided to reduce the dose by 20 percent. She says this is not uncommon, but I'm wondering if this will affect how the cancer is responding. So far she has had a good response with shrinkage and she doesn't want to lose that.