All measured tests are good at predicting the presence of disease on final pathology, but none are able to reliably predict a pathologic complete response.

Ductal carcinoma in situ (DCIS) of the breast historically has been a disease detected by physical examination, diagnosed by open surgical biopsy, and treated by mastectomy and axillary dissection. It is now increasingly detected by screening mammography, diagnosed by needle core biopsy, and treated by lumpectomy, with axillary dissection having been abandoned and sentinel node biopsy being used in axillary staging. However, outcomes related to sentinel node biopsy in DCIS have not been validated in well-controlled clinical trials. Current guideline recommendations are to use sentinel node biopsy when needle core biopsy is highly suspicious for invasive cancer or where there is a high-risk DCIS when lumpectomy identifies invasive breast cancer with the DCIS, or when mastectomy is performed for extensive DCIS. Routine use of sentinel node biopsy for DCIS is not supported.

The need for completion axillary dissection after a positive sentinel node biopsy continues to be challenged. In the 2 years since we last reviewed this subject, a number of authors have shared their experiences about micrometastatic disease and isolated tumor cells, opining both for and against axillary treatment. Data from the ACOSOG Z0011 trial and other small studies do not appear to support the use of completion axillary dissection even for macro-metastatic disease in patients with clinically node-negative (N0) disease. While existing guidelines still recommend axillary dissection for patients with clinically positive nodes, even when conversion to clinically negative disease following neoadjuvant chemotherapy has occurred, this concept is being questioned in ACOSOG Z1071 and in several other recent small trials. The surgical approach to the treatment of breast cancer continues to move away from the traditional Halstedian concept.