This is the exact issue that my wife had, DCIS. Even the Cancer doctor said that DCIS is an environmental problem. Their solution is to get rid of the environment. We ask him if it is an environmental problem, why can't we change the environment. No answer.
The issue that they have with DCIS is I believe two fold.
1. The liability risk. If they do nothing and it turns bad, they could get sued
2. The numbers game. It makes sense to call it cancer so they can cure it! Makes them look good.