Because lichen sclerosis is an uncommon condition, there aren't large-scale studies to support a particular kind of treatment. The most widely-used, however, is topical cortisone creams. These have been found to be effective at keeping the skin pliable.and free of significant side-effects. I assume that your doctor recommend the non-steroid Protopic out of concern for using strong steroids on the penis, but such steroids may be worth a try. Having said that, I think you needn't be worried about Protopic. The evidence isn't that it 'causes cancer,' but that it may be associated with cancer in mice, and there is a lot of controversy about whether that applies to people. We still use it in eczema, but most prefer using steroids first.
Circumcision is often done in men with this condition to help the symptoms of tightness, but I am not aware that it can only occur in uncircumcised men.
You may want to consult academic medical center in your area, where the collective experience of the faculty in treating this condition can be useful.
Best.
Dr. Rockoff
Why is there reason to be concerned with using a steroid cream on the penis?