High CD34-positive cell dose in matched unrelated donor allogeneic hematopoietic stem cell transplant is not associated with graft-versus-host disease or mortality.

BACKGROUND: CD34+ stem cells serve as the primary graft source for allogeneic transplants, with a minimum of 2-4 × 106 cells/kg needed for engraftment. There are conflicting data on outcomes at high stem cell doses, with studies limited by few patients receiving doses far above the minimum target. STUDY DESIGN AND METHODS: In this retrospective, single-center study of patients with hematologic malignancies who underwent matched unrelated donor transplants, we assessed outcomes for engraftment, survival, relapse, and graft-versus-host disease (GVHD) for the highest CD34+ dose quintile (>13 × 106 cells/kg, n = 36) compared to the remaining patients (n = 139). Similar analysis was performed correlating T cell dose and outcomes. RESULTS: There was no difference between the groups in neutrophil engraftment, with a trend toward faster platelet engraftment. There was no significant difference in mortality (adjusted risk ratio [aRR] = 1.02, 95% confidence interval [CI] = 0.85-1.22), relapse (aRR = 1.10, 95% CI = 0.85-1.42), or overall survival by Kaplan-Meier analysis (p = .44). High CD34+ dose was not associated with higher incidence of acute GVHD (aRR = 0.99 grades II-IV, aRR = 1.18 grades III-IV) or chronic GVHD (aRR = 0.87 overall, RR = 1.21 severe). There was limited correlation between CD34+ and T cell dose (R2 = .073), and there was no significant difference in survival, relapse, or GVHD in the highest T cell dose quintile (n = 33) compared to the remaining quintiles (n = 132). DISCUSSION: We found no difference in survival, relapse, or GVHD incidence or severity in patients receiving CD34+ doses above prior cutoffs reported in the literature. These data do not support the routine use of graft CD34+ dose reduction.

Phase II Trial on Extending the Maintenance Flushing Interval of Implanted Ports.

PURPOSE: Retrospective studies suggest that it may be safe to extend the maintenance flushing interval of implanted ports from once every month, as recommended by the manufacturer, to once every 3 months, but no prospective cohort studies have been done specifically assessing the safety and feasibility of this intervention. METHODS: This was a phase II study in oncologic patients who retained a functional port after completion of systemic chemotherapy. Patients enrolled in the study had their port flushed once every 3 months and were observed until completion of five scheduled flushes (one on enrollment and four additional flushes, one every 3 months) or development of any port-related complication, including infections, thrombosis, and occlusions. The primary end points were frequency of port-related complications and port failure requiring removal. RESULTS: A total of 87 patients were enrolled in the study. The median follow-up time was 308 days, accounting for a total of 24,202 catheter-days. There were 10 port-related complications (11.49%; 95% CI, 4.85% to 18.14%). No infection or symptomatic thrombosis occurred. The mean time to port-related complication was 184 days. No patients developed port failure while on protocol, but on subsequent medical record review, four patients developed a complication that required port removal or port revision within 30 days of being removed from the trial (4.6%; 95% CI, 0.4% to 8.8%; 0.17/1,000 catheter-days). CONCLUSION: Extending the maintenance flushes of implanted ports in adult oncologic patients to once every 3 months is safe, effective, and likely to increase patient adherence and satisfaction while decreasing the associated cost.

Exploring Big Data in Hematological Malignancies: Challenges and Opportunities.

Secondary analysis of large datasets has become a useful alternative to address research questions outside the reach of clinical trials. It is increasingly utilized in hematology and oncology. In this review, we provided an overview of some examples of commonly used large datasets in the USA and described common research themes that can be pursued using such a methodology. We selected a sample of 14 articles on adult hematologic malignancies published in 2015 and highlighted their contributions as well as limitations.