Summary Background Patients with locally advanced rectal cancer who achieve a pathological complete response to neoadjuvant chemoradiation have an improved prognosis. The need for surgery in these patients has been questioned, but the proportion of patients achieving a pathological complete response is small. We aimed to assess whether adding cycles of mFOLFOX6 between chemoradiation and surgery increased the proportion of patients achieving a pathological complete response. Methods We did a phase 2, non-randomised trial consisting of four sequential study groups of patients with stage II–III locally advanced rectal cancer at 17 institutions in the USA and Canada. All patients received chemoradiation (fluorouracil 225 mg/m2 per day by continuous infusion throughout radiotherapy, and 45.0 Gy in 25 fractions, 5 days per week for 5 weeks, followed by a minimum boost of 5.4 Gy). Patients in group 1 had total mesorectal excision 6–8 weeks after chemoradiation. Patients in groups 2–4 received two, four, or six cycles of mFOLFOX6, respectively, between chemoradiation and total mesorectal excision. Each cycle of mFOLFOX6 consisted of racemic leucovorin 200 mg/m2 or 400 mg/m2, according to the discretion of the treating investigator, oxaliplatin 85 mg/m2 in a 2-h infusion, bolus fluorouracil 400 mg/m2 on day 1, and a 46-h infusion of fluorouracil 2400 mg/m2. The primary endpoint was the proportion of patients who achieved a pathological complete response, analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00335816. Findings Between March 24, 2004, and Nov 16, 2012, 292 patients were registered, 259 of whom (60 in group 1, 67 in group 2, 67 in group 3, and 65 in group 4) met criteria for analysis. 11 (18%, 95% CI 10–30) of 60 patients in group 1, 17 (25%, 16–37) of 67 in group 2, 20 (30%, 19–42) of 67 in group 3, and 25 (38%, 27–51) of 65 in group 4 achieved a pathological complete response (p=0.0036). Study group was independently associated with pathological complete response (group 4 compared with group 1 odds ratio 3.49, 95% CI 1.39–8.75; p=0.011). In group 2, two (3%) of 67 patients had grade 3 adverse events associated with the neoadjuvant administration of mFOLFOX6 and one (1%) had a grade 4 adverse event; in group 3, 12 (18%) of 67 patients had grade 3 adverse events; in group 4, 18 (28%) of 65 patients had grade 3 adverse events and five (8%) had grade 4 adverse events. The most common grade 3 or higher adverse events associated with the neoadjuvant administration of mFOLFOX6 across groups 2-4 were neutropenia (five in group 3 and six in group 4) and lymphopenia (three in group 3 and four in group 4). Across all study groups, 25 grade 3 or worse surgery-related complications occurred (ten in group 1, five in group 2, three in group 3, and seven in group 4); the most common were pelvic abscesses (seven patients) and anastomotic leaks (seven patients). Interpretation Delivery of mFOLFOX6 after chemoradiation and before total mesorectal excision has the potential to in...

Abstract. While the leukocyte integrin lymphocyte function-associated antigen (LFA)-I has been demonstrated to bind intercellular adhesion molecule (ICAM)-I, results with the related Mac-1 molecule have been controversial. We have used multiple cell binding assays, purified Mac-1 and ICAM-1, and cell lines transfected with Mac-1 and ICAM-1 cDNAs to examine the interaction of ICAM-1 with Mac-1. Stimulated human umbilical vein endothelial cells (HUVECs), which express a high surface density of ICAM-1, bind to immunoaffinity-purified Mac-1 adsorbed to artificial substrates in a manner that is inhibited by mAbs to Mac-1 and ICAM-1. Transfected murine L cells or monkey COS cells expressing human ICAM-1 bind to purified Mac-1 in a specific and dose-dependent manner; the attachment to Mac-1 is more temperature sensitive, lower in avidity, and blocked by a different series of ICAM-1 mAbs when compared to LFA-1. In a reciprocal assay, COS cells cotransfected with the o~ and/3 chain cDNAs of Mac-1 or LFA-1 attach to immunoaffinity-purified ICAM-1 substrates; this adhesion is blocked by mAbs to ICAM-1 and Mac-1 or LFA-1. Two color fluorescence cell conjugate experiments show that neutrophils stimulated with fMLP bind to HUVEC stimulated with lipopolysaccharide for 24 h in an ICAM-I-, Mac-l-, and LFA-l-dependent fashion. Because cellular and purified Mac-1 interact with cellular and purified ICAM-1, we conclude that ICAM-1 is a counter receptor for Mac-1 and that this receptor pair is responsible, in part, for the adhesion between stimulated neutrophils and stimulated endothelial cells.Primary event in the immune system's response to infectious agents is the recruitment of circulating neutrophils to the inflammatory site. Adhesion to the endothelium is the prerequisite physical step for extravasation to the peripheral site of injury. Neutrophil localization has been examined on a molecular level to define both the sequence of events that promotes neutrophil exit from the bloodstream and the cognate proteins on the surface of neutrophils and the endothelial cells that coordinate this interaction.The CDll/CDI8 family defines three high molecular weight, cell surface heterodimeric glycoproteins that have a broad distribution on leukocytes (53). This family, known as the leukocyte integrins, consists of lymphocyte functionassociated antigen (LFA)1-1 (CDlla/CD18; ot 175,000 Mr), Macq (CDllb/CD18; ct 160,000 Mr), and p150,95 (CDllc/ CD18; ot 150,000 Mr); the three proteins share a common 13 (CD18) chain (95,000 Mr) that is noncovalently associated with each unique a chain. These proteins are critical for adhesive functions in the immune system (29): mAbs to LFA-I block leukocyte adhesion to endothelial cells (16,56) 1. Abbt~oviations used in this paper: fMLR formyl methionine-leucinephenylalanine; HE, hydroethidine; HSA, human serum albumin; HUVEC, human umbilical vein endothelial cell; ICAM, intercellular adhesion molecule; IL, interleukin; LFA, lymphocyte function-associated antigen; SFDA, sulfofluorescein &acetate; TEA, trieth...

Abstract. Despite the identification and characterization of several distinct ligands for the leukocyte integrin (CDll/CD18) family of adhesion receptors, little is known about the structural regions on these molecules that mediate ligand recognition. In this report, we use ct subunit chimeras of Mac-1 (CDllb/CD18) and p150,95 (CDllc/CD18), and an extended panel of newly generated and previously characterized mAbs specific to the c~ chain of Mac-1 to map the binding sites for four distinct ligands for Mac-l: iC3b, fibrinogen, ICAM-1, and the as-yet uncharacterized counterreceptor responsible for neutrophil homotypic adhesion. Epitopes of mAbs that blocked ligand binding were mapped with the chimeras and used to localize the ligand recognition sites because the data obtained from functional assays with the Mac-1/p150,95 chimeras were not easily interpreted. Results show that the I domain on the ot chain of Mac-1 is an important recognition site for all four ligands, and that the NH2-terminal and perhaps divalent cation binding regions but not the COOH-terminal segment may contribute. The recognition sites in the I domain appear overlapping but not identical as individual Mac-1-1igand interactions are distinguished by the discrete patterns of inhibitory mAbs. Additionally, we find that the c~ subunit NH2-terminal region and divalent cation binding region, despite being separated by over 200 amino acids of the I domain, appear structurally apposed because three mAbs require the presence of both of these regions for antigenic reactivity, and chimeras that contain the NH: terminus of p150,95 require the divalent cation binding region of p150,95 to associate firmly with the/~ subunit.T HE leukocyte integrins comprise a group of three closely related cell surface receptors that coordinate adhesive interactions in the immune system (82). The members of this subfamily of integrins (37,40) are lymphocyte function-associated antigen (LFA)-I 1 (CDlla/CD18), Mac-1 (CDllb/CD18), and p150,95 (CDllc/CD18). These glycoproteins share a common CD18/~ subunit (95,000 Mr) but have individual CDll st subunits (175,000, 160,000, 150,000 Mr) that are structurally homologous (49). All three st subunits share two prominent features in the extracellular region of the molecule, a putative divalent cation binding region consisting of three tandem repeats of an EF-hand motif, and a 200-amino acid inserted or "I" domain (6,15,16,43,49,70). The I domain is absent in all other known integrin st subunits except for the st1 and st: subunits of the VLA subfamily of integrins (37, 41).A. L. Corbi's current address is Hospital de la Princesa, Unidad de Biologia Molecular, Diego de Leon 62, 28006 Madrid, Spain.I. Abbreviations used in this paper: iC3b-E, iC3b-coated erythrocytes; IgM-E, IgM-coatcd erythrocytes; LFA-I, lymphocyte function-associated antigen-1.Mac-l, which is expressed primarily on myeloid and natural killer cells, has been shown in experiments with blocking mAbs to be responsible, in part, for myeloid cell adhesion to and transmigrati...

IMPORTANCE Guidelines for cancer genetic testing based on family history may miss clinically actionable genetic changes with established implications for cancer screening or prevention.OBJECTIVE To determine the proportion and potential clinical implications of inherited variants detected using simultaneous sequencing of the tumor and normal tissue ("tumor-normal sequencing") compared with genetic test results based on current guidelines.