Welcome LaurieAnn. It's best not to have any breaks, if it's under your control. Sometimes it's not, such as your husband's doctor's recommendation. It can give the tumor a chance to repopulate, but the doctor is aware of this, and may work in the missed days somehow. I had a week break during hurricane Sandy, due to my hospital closing, and then missed three days due to needing a transfusion, and another for hydration. Some they made up by coming in 6 days, instead of five, and tacked the others at the end. They say for every day lost is like having one percent reduction in survival. There may be other considerations, such as the total treatment package, to keep it within a specified time, for optimal effectiveness, so the loss can be minimized. Good luck with everything.