People do see pain, I think, as meaning things are going wrong. Anybody who has had an operation for malignant disease, if they get a pain in their back the following year immediately, say "oh gosh, the cancer has come back" and may want to disregard it because of that. Or else it looms up, it's very important to report any change like that because it may be something quite different. You don't start putting your back out just because you've got cancer. It may be a quite different treatment you need and nothing to do with the disease which has probably been dealt with anyway.