Management of Staphylococcus aureus bacteraemia (SAB) in the oncology patient: Further evidence supports prompt removal of central venous catheters and shorter duration of intravenous antimicrobial therapy.

BACKGROUND: Staphylococcus aureus bacteraemia (SAB) is associated with relatively high risk of complications and high levels of mortality. Internationally, SAB management guidelines lack consensus and especially so regarding oncology patients. This is likely a reflection of insufficient randomised control trials (RCT) and the diversity of SAB patient populations. However, there are 2011 guidelines recommending a minimum of 14 days of appropriate IV antibiotic therapy for SAB. OBJECTIVE: We wished to determine whether our practice of shortened duration of intravenous antimicrobial therapy in favour of oral administration proved as effective as recommended guidelines in a mixed oncology patient cohort. METHODS: Retrospective review of patient records that included any SAB episode among oncology patients from January 2002 to December 2015. Medical chart reviews were undertaken to determine patient demographics, clinical management & antimicrobial therapy, duration of stay, presence of a central venous catheter (CVC) and outcome. RESULTS: Our CVC removal rate was just 73% in SAB where CVC was the identified source of infection, with an attributable mortality rate (<4%) far lower than would be expected. Antimicrobial therapy durations were considerably lower (10 days) than current recommendations of 14 days IV therapy. The recurrence rate of 15% was also significantly lower than has been reported previously. CONCLUSIONS: Our observations contribute new insights concerning the management of SAB in oncology patients. Our findings suggest that therapeutic approaches should perhaps remain individualised and reflective of patient characteristics taking into consideration the complex nature of oncology patients.

Lymph Node Ratio in Sentinel Lymph Node Biopsy Era: Are We Losing Prognostic Information?

BACKGROUND: The number of involved axillary lymph nodes (LNs) found pathologically is regarded as a significant prognostic factor in early-stage breast cancer (EBC). Recently, there is speculation that LN ratio (LNR) may be a better surrogate at predicting cancer-specific outcome than number of involved LNs. This study investigated prognostic value of LNR, using predetermined cutoff values. METHODS: Data included all women diagnosed with node-positive EBC between January 1, 2001, and December 31, 2010 (N = 553). Retrospective evaluation for clinical, demographic, and pathologic data was performed. Most had axillary node clearance (ANC) (548/553; 99.1%). Cohorts were divided by LNR risk groups (low: ≤ 0.20; intermediate: 0.21-0.65; high: >0.65). Proportional hazard modeling was undertaken to evaluate whether LNR was associated with overall survival (OS). RESULTS: Median follow-up was 59.8 months. LNR distribution was as follows: low, 303/553 (54.8%); intermediate, 160/553 (28.9%); high, 90/553 (16.3%). Kaplan-Meier estimates for OS were stratified by LNR: low-risk group had better outcome for OS (P < .001). Overall 5- and 10-year OS was 63% and 58%, respectively. Number of positive LNs correlated with 10-year OS (66%, 48%, and 48% for patients with N1, N2, and N3 stage, respectively; P < .001). LNR also correlated with 5-year OS (69%, 48%, and 41% for low-, intermediate-, and high-risk groups, respectively; P < .001). Significantly, LNR on multivariate analysis also formed a prognostic model when combined with age, estrogen receptor status, PgR status and, HER2 status (P < .001). CONCLUSION: The Findings support LNR as a predictor for OS in EBC. LNR should be considered an independent prognostic variable to current prognostic instruments already in use.

Correlation between Nottingham Prognostic Index and Adjuvant! Online prognostic tools in patients with early-stage breast cancer in Mid-Western Ireland.

BACKGROUND: Prognostic tools are widely used in the practice of oncology and have been developed to help stratify patients into specific risk-related grouping. We sought to apply tool such tools used for patients with early-stage breast cancer (EBC) and correlate them to actual outcomes. METHODS: A retrospective analysis was designed to include EBC cases seen at the Mid-Western Regional Hospital from January 1, 2002, to December 31, 2002. Information was derived from the patients' records, and indices were derived from prognostic tools. Information was analyzed using descriptive statistics and chi-square or Fisher exact test. RESULTS: A total of 77 patients were found, with a median age of 52.2 years. A median overall survival (OS) of 84 months was observed. The majority presented with moderately differentiated estrogen receptor positive invasive ductal carcinoma and lymph node involvement (60%). Sixty-four percent of patients underwent mastectomy as opposed to breast conservation. Adjuvant cytotoxic chemotherapy uptake was 61%, which was comparable to the proportion of node positive disease. The Nottingham Prognostic Index and Adjuvant! Online (AO) tools were both correlated with actual survival, with the AO showing better correlation. CONCLUSIONS: This report underscores that these predicting tools were both underestimations consistent with the actual OS and highlights the importance of further work in validating these tools within our own population.

An optical counting technique with vertical hydrodynamic focusing for biological cells.

A BARRIER IN SCALING LABORATORY PROCESSES INTO AUTOMATED MICROFLUIDIC DEVICES HAS BEEN THE TRANSFER OF LABORATORY BASED ASSAYS: Where engineering meets biological protocol. One basic requirement is to reliably and accurately know the distribution and number of biological cells being dispensed. In this study, a novel optical counting technique to efficiently quantify the number of cells flowing into a microtube is presented. REH, B-lymphoid precursor leukemia, are stained with a fluorescent dye and frames of moving cells are recorded using a charge coupled device (CCD) camera. The basic principle is to calculate the total fluorescence intensity of the image and to divide it by the average intensity of a single cell. This method allows counting the number of cells with an uncertainty +/-5%, which compares favorably to the standard biological methodology, based on the manual Trypan Blue assay, which is destructive to the cells and presents an uncertainty in the order of 20%. The use of a microdevice for vertical hydrodynamic focusing, which can reduce the background noise of out of focus cells by concentrating the cells in a thin layer, has further improved the technique. Computational fluid dynamics (CFD) simulation and confocal laser scanning microscopy images have shown an 82% reduction in the vertical displacement of the cells. For the flow rates imposed during this study, a throughput of 100-200 cellss is achieved.