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Objectives: Management of colorectal cancer warrants mutational analysis of KRAS/NRAS when considering anti-epidermal growth factor receptor therapy and BRAF testing for prognostic stratification. In this multicenter study, we compared a fully integrated, cartridge-based system to standard-of-care assays used by participating laboratories., Methods: Twenty laboratories enrolled 874 colorectal cancer cases between November 2017 and December 2018. Testing was performed on the Idylla automated system (Biocartis) using the KRAS and NRAS-BRAF cartridges (research use only) and results compared with in-house standard-of-care testing methods., Results: There were sufficient data on 780 cases to measure turnaround time compared with standard assays. In-house polymerase chain reaction (PCR) had an average testing turnaround time of 5.6 days, send-out PCR of 22.5 days, in-house Sanger sequencing of 14.7 days, send-out Sanger of 17.8 days, in-house next-generation sequencing (NGS) of 12.5 days, and send-out NGS of 20.0 days. Standard testing had an average turnaround time of 11 days. Idylla average time to results was 4.9 days with a range of 0.4 to 13.5 days., Conclusions: The described cartridge-based system offers rapid and reliable testing of clinically actionable mutation in colorectal cancer specimens directly from formalin-fixed, paraffin-embedded tissue sections. Its simplicity and ease of use compared with other molecular techniques make it suitable for routine clinical laboratory testing., (© American Society for Clinical Pathology, 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Purpose: To identify factors associated with the development of clinically significant venous thrombosis in cancer patients with long-term indwelling subclavian Groshong catheters (GC). Also, to assess both the subsequent performance of affected catheters and the effect of heparin and warfarin therapy on subsequent catheter function and longevity., Methods: Longitudinal study of the outcome of clinical practice. Subset analysis of those catheters developing catheter-related venous thrombosis (CRVT)., Results: Thirty-seven cases of CRVT were identified in a population of 255 consecutive patients in whom a GC was inserted. Seventy percent of the thrombi occurred after an episode of previous catheter dysfunction; only 30% of the thrombi occurred de novo. An unexpectedly high risk of thrombosis was associated with insertion into the left-subclavian circulation (25 of 35 versus 135 of 220, p = 0.02) or with an antecedent episode of aspiration difficulty ("ball-valve effect" [BVE]) (20 of 35 versus 60 of 220, p < 0.01). No correlation was identified between thrombosis and tumor type, tumor histology, or preexisting medical disorders. Once identified, 79% of the involved patients received anticoagulant therapy with sequential heparin and warfarin. Overall longevity of the catheters preserved by anticoagulation (mean dwell = 202 days) far exceeded catheter longevity among the population of catheters that never developed thrombosis (mean dwell = 142 days). The mean catheter longevity after thrombosis (169 days) also exceeded the mean dwell time of all other catheters that were complication-free., Conclusions: CRVT is more likely in patients in whom the catheter is inserted in the left-subclavian circulation or who have experienced a previous episode of aspiration difficulty with the catheter (BVE). Catheter preservation with sequential heparin and warfarin therapy precludes the need for catheter removal and extends dramatically the useful life of the catheter.

Sublines of a human myeloid leukaemia cell line, KBM-3, with increasing degrees of resistance to the antileukaemic agent 4'-(9-acridinlylamino) methanesulphon-m-anisidide (m-AMSA) were evaluated for their response to this drug using a clonogenic assay to measure cell survival and alkaline elution to assess m-AMSA induced DNA strand breakage. Polyacrylamide gel electrophoresis was used to map the protein profiles of the various cell lines. The resistant lines were obtained by intermittent exposure of the KBM-3 cells to the highest tolerated concentration of m-AMSA so that the culture would be repopulated only by the most resistant subpopulation after each exposure. Two distinct phases were apparent during the development of resistance. During the first 14 months of intermittent exposure to maximally tolerated concentrations of m-AMSA, the cells developed low-degree m-AMSA resistance (5-7-fold as compared with the parent line, as measured by cell survival). This low-degree resistance was characterised by a somewhat suppressed level of DNA strand breakage and no measurable change in cellular protein levels. Subsequently, a single escalation of the m-AMSA retreatment concentration resulted in a cell population that was approximately 100-fold resistant, as assessed by cloning. This rapid phenotypic change temporally coincided with the acquisition of an almost complete refractoriness to m-AMSA-induced DNA strand breakage and the loss of a cellular 76 kDa protein. We suggest that the loss of this protein is important for the development of a highly m-AMSA resistant phenotype.