Endoscopy Is Not Associated with Infectious Adverse Events After Hematopoietic Cell Transplantation: A Retrospective Cohort Study.

BACKGROUND: Patients with recent hematopoietic cell transplantation (HCT) are considered high risk for gastrointestinal endoscopy due to the potential for procedural bacterial translocation. Prior studies investigating these risks do not account for the higher baseline rate of infectious complications among those who are immunocompromised. We performed a retrospective cohort study of patients with recent HCT who underwent endoscopy and their matched controls who did not undergo endoscopy. METHODS: We identified patients who underwent HCT followed by upper and/or lower endoscopy at the University of Pennsylvania from 2000 to 2018. Individuals were matched 1:1 by age, sex, and type of HCT to controls who underwent HCT without subsequent endoscopy. Infectious adverse events were assessed by Sepsis-3 and Sepsis-2 criteria. Factors associated with infectious adverse events after endoscopy/index date were assessed using multivariable conditional logistic regression. RESULTS: We identified 149 patients who underwent HCT and endoscopy and 149 matched controls who underwent HCT without endoscopy. Sepsis-3 infectious adverse events occurred in 3.4% of patients in each group. Sepsis-2 infectious adverse events occurred in 20.1% of patients who underwent endoscopy compared to 19.5% of controls. There was no association between endoscopy and Sepsis-2 infectious adverse events in the multivariable regression analysis (adjusted odds ratio 1.65, 95% CI 0.51-5.26). CONCLUSIONS: When compared to controls with similar immune statuses, patients who underwent endoscopy after HCT did not have a higher risk of infectious adverse events. These results may inform clinical decision making regarding the risks and benefits of endoscopic management after HCT.

Imaging the Met Receptor Tyrosine Kinase (Met) and Assessing Tumor Responses to a Met Tyrosine Kinase Inhibitor in Human Xenograft Mouse Models with a [99mTc] (AH-113018) or Cy 5** (AH-112543) Labeled Peptide.

Developing an imaging agent targeting the hepatocyte growth factor receptor protein (Met) status of cancerous lesions would aid in the diagnosis and monitoring of Met-targeted tyrosine kinase inhibitors (TKIs). A peptide targeting Met labeled with [(99m)Tc] had high affinity in vitro (Kd = 3.3 nM) and detected relative changes in Met in human cancer cell lines. In vivo [(99m)Tc]-Met peptide (AH-113018) was retained in Met-expressing tumors, and high-expressing Met tumors (MKN-45) were easily visualized and quantitated using single-photon emission computed tomography or optical imaging. In further studies, MKN-45 mouse xenografts treated with PHA 665752 (Met TKI) or vehicle were monitored weekly for tumor responses by [(99m)Tc]-Met peptide imaging and measurement of tumor volumes. Tumor uptake of [(99m)Tc]-Met peptide was significantly decreased as early as 1 week after PHA 665752 treatment, corresponding to decreases in tumor volumes. These results were comparable to Cy5**-Met peptide (AH-112543) fluorescence imaging using the same treatment model. [(99m)Tc] or Cy5**-Met peptide tumor uptake was further validated by histologic (necrosis, apoptosis) and immunoassay (total Met, p Met, and plasma shed Met) assessments in imaged and nonimaged cohorts. These data suggest that [(99m)Tc] or Cy5**-Met peptide imaging may have clinical diagnostic, prognostic, and therapeutic monitoring applications.

Macrophages Promote Circulating Tumor Cell-Mediated Local Recurrence following Radiotherapy in Immunosuppressed Patients.

Although radiotherapy (RT) decreases the incidence of locoregional recurrence in breast cancer, patients with triple-negative breast cancer (TNBC) have increased risk of local recurrence following breast-conserving therapy. The relationship between RT and local recurrence is unknown. Here, we tested the hypothesis that recurrence in some instances is due to the attraction of circulating tumor cells to irradiated tissues. To evaluate the effect of absolute lymphocyte count on local recurrence after RT in patients with TNBC, we analyzed radiation effects on tumor and immune cell recruitment to tissues in an orthotopic breast cancer model. Recurrent patients exhibited a prolonged low absolute lymphocyte count when compared with nonrecurrent patients following RT. Recruitment of tumor cells to irradiated normal tissues was enhanced in the absence of CD8+ T cells. Macrophages (CD11b+F480+) preceded tumor cell infiltration and were recruited to tissues following RT. Tumor cell recruitment was mitigated by inhibiting macrophage infiltration using maraviroc, an FDA-approved CCR5 receptor antagonist. Our work poses the intriguing possibility that excessive macrophage infiltration in the absence of lymphocytes promotes local recurrence after RT. This combination thus defines a high-risk group of patients with TNBC.Significance: This study establishes the importance of macrophages in driving tumor cell recruitment to sites of local radiation therapy and suggests that this mechanism contributes to local recurrence in women with TNBC that are also immunosuppressed.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/15/4241/F1.large.jpg Cancer Res; 78(15); 4241-52. ©2018 AACR.