Bone marrow micrometastases do not impact disease-free and overall survival in early stage sentinel lymph node-negative breast cancer patients.

BACKGROUND: The presence of lymph node metastases is the most important prognostic factor in early stage breast cancer. Whether bone marrow micrometastases (BMM) impact the prognosis in sentinel lymph node (SLN)-negative breast cancer patients remains a matter of debate. Therefore, the objective of this study was to assess the impact of BMM on 5-year disease-free and overall survival among those patients. METHODS: We analyzed 410 patients with early stage breast cancer (pT1 and pT2 ≤ 3 cm, cN0) who were prospectively enrolled into the Swiss Multicenter Sentinel Lymph Node Study in Breast Cancer between January 2000 and December 2003. All patients underwent bone marrow aspiration followed by SLN biopsy. All SLN were stained with hematoxylin and eosin and immunohistochemistry (Lu-5, CK-22). Cancer cells in the bone marrow were identified after staining with monoclonal antibodies A45-B/B3 against CK-8, -18, and -19. RESULTS: Negative SLN were found in 67.6% (277 of 410) of the enrolled patients. Of those, BMM status was negative in 75.8% (210 of 277) and positive in 24.2% (67 of 277) patients. Median follow-up was 61 (range 11-96) months. Five-year disease-free survival was 93.6% (95% confidence interval [CI] 89.1-96.0) in BMM-negative and 92.2% (95% CI 82.5-96.2) in BMM-positive patients (p = 0.50). Five-year overall survival was 92.7% (95% CI 87.9-95.8) for the BMM-negative and 92.5% (95% CI 83.4-96.2) for the BMM-positive group (p = 0.85). CONCLUSIONS: This is one of the first prospective studies to examine 5-year disease-free and overall survivals in SLN-negative patients in correlation to their BMM status. Although BMM are identified in one of four SLN-negative patients, they do not impact disease-free and overall survival.

Accuracy of frozen section of sentinel lymph nodes: a prospective analysis of 659 breast cancer patients of the Swiss multicenter study.

OBJECTIVE: To assess the accuracy of sentinel lymph node (SLN) frozen section in a prospective multicenter study of early-stage breast cancer patients. SUMMARY BACKGROUND DATA: The decision to perform an immediate completion axillary node dissection (ALND) is based on results of SLN frozen section. However, SLN frozen sections are not routinely performed in all centers. Moreover, the accuracy of SLN frozen section remains a matter of great debate. METHODS: Prospective multicenter trial analyzing 659 early stage breast cancer patients (pT1 and pT2

CD34+ cord blood cell-transplanted Rag2-/- gamma(c)-/- mice as a model for Epstein-Barr virus infection.

Recent studies suggest that Epstein-Barr virus (EBV) can infect naïve B cells, driving them to differentiate into resting memory B cells via the germinal center reaction. This hypothesis has been inferred from parallels with the biology of normal B cells but has never been proven experimentally. Rag2(-/-) gamma(c)(-/-) mice that were transplanted with human CD34(+) cord blood cells as newborns were recently shown to develop human B, T, and dendritic cells, constituting lymphoid organs in situ. Here we used this model to better define the strategy of EBV infection of human B cells in vivo and to compare this model system with different conditions of EBV infection in humans. Our results support the model of EBV persistence in vivo in cases that were characterized by follicular hyperplasia and a relatively normal CD4(+) and CD8(+) T-cell distribution. Intriguingly, in cases that were characterized by nodular and diffuse proliferation with a preponderance of CD8(+) T cells, similar to infectious mononucleosis, EBV still infects naïve B cells but also induces clonal expansion and ongoing somatic mutations without germinal center reactions. Our results reveal different strategies of EBV infection in B cells that possibly result from variations in the host immune response. Future experiments might allow understanding of the mechanisms responsible for persistent EBV infection and provide targets for more highly tailored therapeutic interventions.

Morbidity of sentinel lymph node biopsy (SLN) alone versus SLN and completion axillary lymph node dissection after breast cancer surgery: a prospective Swiss multicenter study on 659 patients.

OBJECTIVE: To assess the morbidity after sentinel lymph node (SLN) biopsy compared with SLN and completion level I and II axillary lymph node dissection (ALND) in a prospective multicenter study. SUMMARY BACKGROUND DATA: ALND after breast cancer surgery is associated with considerable morbidity. We hypothesized: 1) that the morbidity in patients undergoing SLN biopsy only is significantly lower compared with those after SLN and completion ALND level I and II; and 2) that SLN biopsy can be performed with similar intermediate term morbidity in academic and nonacademic centers. METHODS: Patients with early stage breast cancer (pT1 and pT2

Association of the presence of bone marrow micrometastases with the sentinel lymph node status in 410 early stage breast cancer patients: results of the Swiss Multicenter Study.

BACKGROUND: The sentinel lymph node (SLN) status has proven to accurately reflect the remaining axillary lymph nodes and represents the most important prognostic factor. It is unknown whether an association exists between the SLN status and the presence of bone marrow (BM) micrometastases. The objective of the present investigation was to evaluate whether or not such an association exists. METHODS: In the present investigation 410 patients with early stage breast cancer (pT1 and pT2

Human adaptive immune system Rag2-/-gamma(c)-/- mice.

Although many biologic principles are conserved in mice and humans, species-specific differences exist, for example, in susceptibility and response to pathogens, that often do not allow direct implementation of findings in experimental mice to humans. Research in humans, however, for ethical and practical reasons, is largely restricted to in vitro assays that lack components and the complexity of a living organism. To nevertheless study the human hematopoietic and immune system in vivo, xenotransplantation assays have been developed that substitute human components to small animals. Here, we summarize our recent findings that transplantation of human cord blood CD34(+) cells to newborn Rag2(-/-)gamma(c)(-/-) mice leads to de novo development of major functional components of the human adaptive immune system. These human adaptive immune system Rag2(-/-)gamma(c)(-/-) (huAIS-RG) mice can now be used as a technically straightforward preclinical model to evaluate in vivo human adaptive immune system development as well as immune responses, for example, to vaccines or live infectious pathogens.

Development of a human adaptive immune system in cord blood cell-transplanted mice.

Because ethical restrictions limit in vivo studies of the human hemato-lymphoid system, substitute human to small animal xenotransplantation models have been employed. Existing models, however, sustain only limited development and maintenance of human lymphoid cells and rarely produce immune responses. Here we show that intrahepatic injection of CD34+ human cord blood cells into conditioned newborn Rag2-/-gammac-/- mice leads to de novo development of B, T, and dendritic cells; formation of structured primary and secondary lymphoid organs; and production of functional immune responses. This provides a valuable model to study development and function of the human adaptive immune system in vivo.

Mammareconstruction with skin-expander and silicone prostheses: 15 years' experience.

We report on 170 breasts that were reconstructed with Skin-Expander and silicone implants over a period of 15 years [1,2]. Reconstruction occurred primarily in only about one-third of the cases, since the information provided by the first doctor in charge regarding the possibilities of breast reconstruction was rather scanty. In cases treated with radiotherapy, reconstruction with Skin-Expander should not be excluded, but it is necessary to proceed with extreme caution and to give patients exact information. The complication rate is higher here than in cases which have not been exposed to radiotherapy. The final result depends directly on the primary surgery and the skin as well as the contralateral breast quality [3]. In most cases reconstruction with Skin-Expander and silicone implants meets the patients' desires: low-risk operation, fewer additional scars, and similar and improved breasts on both sides.