Risk of infection among patients with non-metastatic solid tumors or non-Hodgkin's lymphoma receiving myelosuppressive chemotherapy and antimicrobial prophylaxis in US clinical practice

Long-term use of broad-spectrum antibiotics affects Ly6Chi monocyte recruitment and IL-17A and IL-22 production through the gut microbiota in tumor-bearing mice treated with chemotherapy

The protective effects of antibiotics against infection in cancer patients treated with chemotherapy remains unclear and related studies have been performed in healthy or pathogen-infected animal models. Here, we aimed to study the effects of antibiotic use on intestinal infection in tumor-bearing mice treated with chemotherapy and to determine the underlying mechanisms. Subcutaneous CT26 tumor-bearing mice were assigned to four groups: the control (Ctrl) group without any treatment, the antibiotic (ATB) group treated with a mixture of ampicillin, streptomycin, and colistin, the 5-fluorouracil (FU) group treated with four cycles of intraperitoneal injections of FU, and the ATB + FU group treated with the combination of ATB and FU. Gut microbial composition was determined and mesenteric lymph nodes (mLNs) were isolated for bacterial culturing. Intestinal permeability and integrity were assessed and the expression of cytokines was analyzed by quantitative PCR, ELISA, or flow cytometry (FCM). Monocytes in the colonic lamina propria (LP) were measured by FCM. Compared with the Ctrl and FU groups, the numbers of positive bacterial culturing results for mLNs were higher, and gut bacterial compositions were altered in the ATB and ATB + FU groups, with significantly decreased alpha diversity in the ATB + FU group. Intestinal integrity regarding the expression of tight junction proteins and intestinal permeability were not impaired significantly after treatments, but the colons were shorter in the ATB + FU group. The expression levels of intestinal IL-17A and IL-22, as well as the percentages of IL-17A⁺ cells in the colonic LP of the ATB + FU group, were lower than those in the FU group. The percentages of Ly6C^hi monocytes in the colonic LP were lower, but those in the spleen were higher in the ATB + FU group than in the FU group. The mRNA levels of colonic CCL8 were reduced in the ATB + FU group. Antibiotic use is associated with an increased incidence of intestinal infections in tumor-bearing mice treated with chemotherapy, which might in turn be associated with a dysregulated gut microbiota that inhibits colonic monocyte recruitment and IL-17A and IL-22 production.

Cerebral HSV-1 Vasculitis as a Fatal Complication of Immunosuppression in Non-Hodgkin´s Lymphoma: A Case Report and Review of the Literature

Patients with lymphoma are predisposed to infection because of the immunocompromised state related to the disease itself and as a consequence of chemo-/radiotherapy. Here, we report a case of Herpes-simplex virus encephalitis (HSE) in an immunosuppressed patient with splenic marginal zone lymphoma (SMZL), a rare indolent variant of non-Hodgkin´s lymphoma (NHL). The course was complicated febrile neutropenia and HSV-1-related cerebral vasculitis causing progressive ischemic stroke. This case illustrates the expanding spectrum of atypical clinical and radiological manifestations of HSE in patients treated with myelotoxic drugs. Moreover, we summarize the few central nervous system manifestations of SMZL reported in the literature and discuss distinct causes of neurological deterioration in patients with NHL.

Eastern Canadian Gastrointestinal Cancer Consensus Conference 2016

The annual Eastern Canadian Gastrointestinal Cancer Consensus Conference 2016 was held in Montreal, Quebec, 5-7 February. Experts in radiation oncology, medical oncology, surgical oncology, and infectious diseases involved in the management of patients with gastrointestinal malignancies participated in presentations and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses multiple topics: ■ Follow-up and survivorship of patients with resected colorectal cancer■ Indications for liver metastasectomy■ Treatment of oligometastases by stereotactic body radiation therapy■ Treatment of borderline resectable and unresectable pancreatic cancer■ Transarterial chemoembolization in hepatocellular carcinoma■ Infectious complications of antineoplastic agents.