Available mouse models of ductal carcinoma in situ (DCIS) and BRCA1-mutation-related breast cancer are reviewed. The best validated mouse models of human DCIS are the conditional estrogen receptor α in mammary tissue (CERM) model initiated by deregulated estrogen receptor α and the serial explant mouse model initiated by p53 deficiency. At present the most useful and best validated mouse model of BRCA1-mutation-related breast cancer uses the cre-lox system to make a conditional Brca1 deletion targeted to mammary epithelial cells. The major shortcoming of the non-conditional Brca1 models is the high incidence of non-mammary tumor development. The use of mammary gland transplants or explants from these mice into nude hosts is one approach that could be used to circumvent this deficiency. Development and validation of a Brca1-mutation-related mouse model of basal cell breast cancer is an important next step.

As widespread screening for breast cancer detects more women at younger ages and earlier stages, the need for minimally invasive, cosmetically preferable approaches to its treatment grows. The combination of a superficial location on the thorax and lack of intervening organs makes the breast ideal for ablative therapies, one of which is cryoablation. Cryoablation destroys tissue through multiple cycles of localized freezing. Major advantages to cryoablation are: the ability to perform the procedure in the office under real-time ultrasound guidance, improved post-procedure cosmesis when compared to breast conserving surgery since only a 2 mm skin incision is necessary, and the avoidance of anesthesia since freezing numbs the breast. Numerous studies, reviewed here, have demonstrated success in eradication of invasive breast cancer using this modality. However, before cryoablation can be added to the armamentarium of those who treat breast cancer, prospective randomized trials are needed to determine its long-term effectiveness.

Radiation therapy is an important part of the modern multimodality treatment of breast cancer, and in the past decade has had an increasing role in the treatment of patients at intermediate to high risk for local-regional recurrence after mastectomy. During the same time period, a less radical surgical approach to mastectomy has developed that is more compatible with reconstruction, and a greater number of young patients diagnosed due to screening who are more motivated and candidates for the procedure. This has led to an increased need to consider the special implications of combining radiation with breast reconstruction. This review will focus on reconstruction by tissue expander and breast implants. A multidisciplinary approach to management is needed that includes a team of a plastic surgeon, and radiation, surgical and medical oncologists. Experience with implant reconstruction and radiation in the past decade has been associated with relatively high rates of complications and/or implant loss compared with unirradiated patients. However, newer techniques of radiation, and improved patient selection and coordination between the multidisciplinary team offer the promise of low complication rates and good or excellent cosmetic results for most patients in the future.