If a woman is diagnosed with breast cancer, how important is it for her to get a second opinion about her diagnosis?

Today, most pathology labs run special tests on the cancer cells to make certain the diagnosis is correct.  Staging a tumor surgically is also fairly straight forward.  When it comes to chemotherapy, this is where some differences of opinion may occur and a second opinion may be a good idea.  Today, oncologists often go to a cookbook put out by the NCCN.  This cookbook approach may not take all of your cancer characteristics into account.  You want to find an experienced oncologist who will look at your big picture to make sure you are not under or over treated.