[Sentinel node and breast cancer: A state-of-the-art in 2019]

Since 1994 and Giuliano's description of sentinel lymph node technique, this procedure has considerably improved and is nowadays, one of the essential pillars in the management of breast cancer. Neoadjuvant chemotherapy (NAC) is effective on regional control, especially on axillary lymph node. Various learned societies recommend that the initial proved GS can be realized before (CNGOF 2010, Saint-Paul de Vence 2013, ESMO 2015, St-Gallen 2015, NCCN 2016) or after (ASCO 2014, ESMO 2015, Saint-Gallen 2015) CNA when the patient is considered like N0. In patients with initial lymph node involvement, GS searching it is not yet recommended. SLN detection before NAC remains an important prognostic factor especially in N+ patients before surgery. The purpose of this article was a reviewing of medical literature regarding possible indications for SLN detection and axillary dissection in patients with NAC according to sentinel lymph node status. The secondary objective was to put forward different perspectives and studies dealing with this subject. The complete pathological response appears to be an important selection criterion for proposing SLN to these patients and avoiding a "useless" AD. It is important to include patients in the trials to make recommendations progress on SLN after NAC and avoid a rate of uninjured AD.

Endotoxin-induced myeloid-derived suppressor cells inhibit alloimmune responses via heme oxygenase-1

Inflammation and cancer are associated with impairment of T-cell responses by a heterogeneous population of myeloid-derived suppressor cells (MDSCs) coexpressing CD11b and GR-1 antigens. MDSCs have been recently implicated in costimulation blockade-induced transplantation tolerance in rats, which was under the control of inducible NO synthase (iNOS). Herein, we describe CD11b+GR-1+MDSC-compatible cells appearing after repetitive injections of lipopolysaccharide (LPS) using a unique mechanism of suppression. These cells suppressed T-cell proliferation and Th1 and Th2 cytokine production in both mixed lymphocyte reaction and polyclonal stimulation assays. Transfer of CD11b+ cells from LPS-treated mice in untreated recipients significantly prolonged skin allograft survival. They produced large amounts of IL-10 and expressed heme oxygenase-1 (HO-1), a stress-responsive enzyme endowed with immunoregulatory and cytoprotective properties not previously associated with MDSC activity. HO-1 inhibition by the specific inhibitor, SnPP, completely abolished T-cell suppression and IL-10 production. In contrast, neither iNOS nor arginase 1 inhibition did affect suppression. Importantly, HO-1 inhibition before CD11b+ cell transfer prevented the delay of allograft rejection revealing a new MDSC-associated suppressor mechanism relevant for transplantation.

Endotoxin-induced myeloid-derived suppressor cells inhibit alloimmune responses via heme oxygenase-1

Inflammation and cancer are associated with impairment of T-cell responses by a heterogeneous population of myeloid-derived suppressor cells (MDSCs) coexpressing CD11b and GR-1 antigens. MDSCs have been recently implicated in costimulation blockade-induced transplantation tolerance in rats, which was under the control of inducible NO synthase (iNOS). Herein, we describe CD11b+GR-1+MDSC-compatible cells appearing after repetitive injections of lipopolysaccharide (LPS) using a unique mechanism of suppression. These cells suppressed T-cell proliferation and Th1 and Th2 cytokine production in both mixed lymphocyte reaction and polyclonal stimulation assays. Transfer of CD11b+ cells from LPS-treated mice in untreated recipients significantly prolonged skin allograft survival. They produced large amounts of IL-10 and expressed heme oxygenase-1 (HO-1), a stress-responsive enzyme endowed with immunoregulatory and cytoprotective properties not previously associated with MDSC activity. HO-1 inhibition by the specific inhibitor, SnPP, completely abolished T-cell suppression and IL-10 production. In contrast, neither iNOS nor arginase 1 inhibition did affect suppression. Importantly, HO-1 inhibition before CD11b+ cell transfer prevented the delay of allograft rejection revealing a new MDSC-associated suppressor mechanism relevant for transplantation.