Peter H. Shaw

A comparison of clinical trial enrollment between adolescent and young adult (AYA) oncology patients treated at affiliated adult and pediatric oncology centers.

Purpose Over the past 30 years, there has been a dramatic increase in the survival rates of younger pediatric cancer patients in contrast to adolescent and young adult (AYA) oncology patients. The reasons for this discrepancy are multifactorial, but it is clear that clinical trial enrollment correlates with better outcomes. Patients and Methods We examined the rate of clinical trial accrual of AYA oncology patients (aged 15 to 22 y) treated at affiliated pediatric and adult cancer centers, the Childrens Hospital of Pittsburgh and the University of Pittsburgh Cancer Institute. We retrospectively analyzed all new cancer diagnoses and clinical trial enrollment status between 2003 and 2006 for AYA patients at both institutions. Results There were 91 new AYA cancer diagnoses at Childrens Hospital of Pittsburgh, of which 24 (26%) were enrolled on a clinical trial. During the same time period, only 5 of 121 new AYA cancer patients (4%) at University of Pittsburgh Cancer Institute were enrolled on a clinical trial, which was significantly lower (P<0.001). Conclusions Our data demonstrate that clinical trial enrollment was superior when AYA patients were treated at a pediatric cancer center. As most AYA patients are not treated at pediatric centers, this may partly explain why their cure rates have not improved as significantly as younger pediatric oncology patients.

Different rates of clinical trial enrollment between adolescents and young adults aged 15 to 22 years old and children under 15 years old with cancer at a children's hospital.

Background Over the last 30 years significant strides have been made in cure rates for children with cancer, but these improvements have not been seen in adolescents and young adults. The reasons for this lack of progress are multifactorial, but it is clear greater cure rates are correlated with controlled clinical trials. Our objective was to see if pediatric patients over the age of 15 had a lower rate of clinical trial enrollment, and if so, why. Methods We retrospectively analyzed the clinical data on all patients with new oncology diagnoses at Childrens Hospital of Pittsburgh (CHP) diagnosed over a 5-year period from July 2001 to June 2006. Results Six hundred and forty new oncology patients were seen at CHP over this time, 501 under 15 years old and 139 patients aged 15 to 22. Thirty-six percent of all patients were treated on a clinical trial, including 38% of the younger patients and 27% of the older patients (P=0.03). Fifty-seven percent in the older group were not enrolled on a clinical trial because one was not available versus 41% in the younger group (P=0.04). There were no significant differences between the age groups when other reasons were analyzed. Conclusions A significantly lower proportion of adolescents and young adults patients (aged 15 to 22) were placed on a treatment trial than younger patients. The lack of an open clinical trial was the main reason for this deficit. Interventions to address this discrepancy need to be instituted on a national level.

Improved clinical trial enrollment in adolescent and young adult (AYA) oncology patients after the establishment of an AYA oncology program uniting pediatric and medical oncology divisions

Since 1975, there has been a dramatic increase in the survival rates of pediatric and older cancer patients, but adolescent and young adult (AYA) patients ages 15 to 40 years have not had a similar improvement. Data indicate a direct correlation between increased cure rates and clinical trial enrollment.

Novel therapeutic approaches in the treatment of children with hepatoblastoma.

Hepatoblastoma is the most common liver tumor diagnosed in children. Children with persistently unresectable disease, metastatic disease at presentation, recurrent disease, or slowly declining alpha-fetoprotein levels are at high risk for recurrence, exhibit an extremely poor prognosis, and are in desperate need of novel therapeutic agents and strategies. Four high-risk patients were treated. One patient with a local recurrence was treated with irinotecan followed by orthotopic liver transplant. Three patients were treated with tandem high-dose chemotherapy (HDT) with autologous stem cell rescue (two with primary metastatic disease and one with recurrent disease). All three of the patients treated with HDT had relapse (two of them subsequently received irinotecan); the remaining patient underwent surgical resection of a solitary recurrent pulmonary metastasis. Irinotecan demonstrated significant antitumor effects in all three treated patients and was well tolerated. None of the three patients treated with HDT remained disease-free, although the patient who underwent surgical resection of a solitary recurrent pulmonary metastasis remains disease-free 6 years from diagnosis. Further exploration of the use of irinotecan is warranted in high-risk patients with hepatoblastoma.

Analysis of national and single-center incidence and survival after liver transplantation for hepatoblastoma: New trends and future opportunities

BACKGROUND Liver transplantation (LTx) for hepatoblastoma appears to be increasing. Favorable tumor histology is increasingly linked to survival after surgical resection and could also determine posttransplantation outcomes. METHODS To evaluate national trends in tumor and LTx incidence as the basis for observations at some LTx centers, and determinants of survival after LTx for hepatoblastoma, we queried the National Cancer Institutes Surveillance, Epidemiology and End Results (SEER) registry representing 9.451% of the U.S. population (1975-2007), the United Network for Organ Sharing (UNOS, 1988-2010, n = 332), and Childrens Hospital of Pittsburgh database (CHP, 1987-2011, n = 35). RESULTS In the United States, hepatoblastoma cases increased 4-fold, LTx for hepatoblastoma increased 20-fold, and hepatoblastoma surpassed other unresectable liver malignancies requiring LTx by nearly 3-fold. Actuarial 5-year patient survival exceeded 75%. Recurrences in 16% were greater after segmental LTx in the total U.S. experience (P = .049). At CHP, 5 children died from recurrences (n = 4) and sepsis (n = 1). Tumors were epithelial (57%) or mixed epithelial-stromal (42%), Childrens Oncology Group stage III (77%) or IV (23%). Recurrences were related to previous pulmonary metastases (P = .016), and tumor necrosis <50% (P = .013), but not to small cell undifferentiated tumor histology (P = NS). Hepatic artery thrombosis was more common after LTx for hepatoblastoma compared with nonmalignant indications (P = .0089). Thirty-three children received pre-LTx chemotherapy, 88.6% with cisplatin, and 85.7% received post-LTx chemotherapy. CONCLUSION Outcomes after LTx for hepatoblastoma may benefit from improved detection and treatment of pretransplantation metastases, adequate tumor lysis after chemotherapy, and perioperative antithrombotic agents but are unaffected by undifferentiated tumor histology.

The prevalence of bleeding disorders among healthy pediatric patients with abnormal preprocedural coagulation studies

Background We evaluated the prevalence of hemostatic disorders among pediatric patients with abnormal screening coagulation tests. Procedure We analyzed 48 consecutive referrals for abnormal prothrombin times, partial thromboplastin times, or closure times obtained as preprocedural screens. Patients were evaluated by uniform diagnostic testing. Results Seventeen patients (35%) had an isolated nonspecific inhibitor (NSI). Six patients (12.5%) presented with mildly low factor activity with a concomitant NSI. These deficiencies were of unclear clinical significance. One patient (2%) had a lupus anticoagulant. Only 9 patients (19%) had a possible or true mild bleeding disorder: 5 patients (10%) had isolated low von Willebrand factor levels, 2 patients (4%) had possible type I von Willebrand disease, and 2 (4%) had platelet aggregation disorders. In all patients, personal and family bleeding history had a positive predictive value of 45% for hemostatic disorders. Conclusions The most common diagnosis among the patients referred to us for abnormal preoperative coagulation tests was a NSI, which is not associated with an increased risk of operative bleeding complications. Less than 20% had a possible or true mild bleeding disorder. Although certain bleeding disorders can be occult in children and are associated with perioperative bleeding risks, our study demonstrates the inherent limitations in making a laboratory diagnosis of a bleeding disorder in pediatric patients preoperatively. Our findings contribute to existing doubt about the usefulness of prothrombin times, partial thromboplastin times, and closure times to identify occult bleeding disorders in this population.

Adolescent and young adult (AYA) oncology in the United States: A specialty in its late adolescence

Over the last 30 years, it has become apparent that oncology patients ages 15 to 39 have not reaped the same rewards of improved survival that we have seen in younger and older patients. As a result, in 2006 the Adolescent and Young Adult (AYA) Oncology Progress Review Group convened and examined the factors that impact the care of the 70,000 new cases per year (approximately 7% of all new cases) in the United States and published their findings. The reasons for inferior survival gains are of course multiple and include the settings in which patients are cared for, clinical trial enrollment, insurance coverage, varied treatment of sarcomas, varied treatment of acute lymphoblastic leukemia, the psychosocial impact of cancer and cancer survivorship. A new area of a yet-to-be completely defined subspecialty was born out of this meeting: AYA oncology. As a medical community we realized that these patients do not fit neatly into the pediatric nor adult world and, therefore, require a unique approach which many individuals, oncology centers, advocacy groups, and cooperative trial groups have started to address. This group of dedicated providers and advocates has made strides but there is still much work to be done on the local, national, and international level to make up for shortcomings in the medical system and improve outcomes. We review key components of AYA cancer care in 2015 that all providers should be aware of, how far we have come, where this movement is headed, and the obstacles that continue to stand in the way of better cure rates and quality of life after cure for this unique group of patients. Like an adolescent maturing into adulthood, this movement has learned from the past and is focused on moving into the future to achieve its goals.

Expansion of megakaryocyte precursors and stem cells from umbilical cord blood CD34+ cells in collagen and liquid culture media

Umbilical cord blood (UCB) is now commonly used as a source of stem cells for hematopoietic reconstitution following myeloablative therapy in patients with a variety of diseases. Although UCB is a rich source of stem cells, platelet engraftment occurs at a median of 71 days which is significantly prolonged compared to allogeneic bone marrow. The number of megakaryocyte (MK) precursors in stem cell harvests appears to correlate inversely with the time to platelet engraftment. In an effort to increase the number of platelet precursors, we cultured CD34-selected cord blood mononuclear cells (MNC) in serum-free collagen medium with numerous cytokine combinations. The cells were cultured with four cytokines: interleukin-3 (IL-3), thrombopoietin (TPO), stem cell factor (SCF), and Flt-3); five cytokines, IL-3, TPO, SCF, Flt-3 plus granulocyte-macrophage colony-stimulating factor (GM-CSF), or erythropoietin (Epo); or all six cytokines in combination. After 16 days, significant expansion of MK precursors (CD41(+)) and stem cells (CD34(+) and AC133(+) cells) were seen in cells cultured in IL-3, TPO, SCF, and Flt-3 with or without GM-CSF compared to the combinations that contained Epo (p < 0.05). Similar studies were performed using liquid culture medium, and after 14 days the number of MNCs, CD34(+), AC133(+), CD41(+), and CD61(+) cells were higher in the UCB cells cultured in IL-3, TPO, SCF, and Flt-3 compared to those cultured with those four cytokines plus GM-CSF. These results demonstrate that UCB stem cells can be effectively expanded ex vivo and enriched with platelet precursors using TPO, SCF, Flt-3, and IL-3, whereas the addition of Epo and GM-CSF is unnecessary.

Improving enrollment in clinical trials for adolescents with cancer

Overall cancer cure rates have risen over the last 30 years. Adolescent and young adult (AYA) oncology patients aged 15 to 39 have not shared in these successes as an age group, including those who fall into the younger age group of 15 to 19 years. The reasons for this deficit in survival improvement are manifold, but research has shown that an important factor is decreased enrollment in therapeutic clinical trials in this population versus younger patients. The paucity of adolescents treated in clinical trials is itself the result of several elements of the health care landscape in the United States. On the local level, these factors include referral patterns and facilities available; on the national level, related factors include the number of clinical trials available for this age group and health care provider education in the care of these patients. We examine the data available that have contributed to this deficit in the United States and offer broad strategies to address these shortcomings with the goal of improving outcomes in this underserved population.

Ex vivo expansion of megakaryocyte precursors from umbilical cord blood CD34+ cells in a closed liquid culture system

Umbilical cord blood (UCB) provides a rich source of stem cells for transplantation after myeloablative therapy. One major disadvantage of UCB transplantation is delayed platelet engraftment. We propose to hasten platelet engraftment by expanding the number of megakaryocyte (MK) precursors (CD34/CD41 cells) through cytokine stimulation within a closed, pre-clinical liquid culture system. Clinical engraftment data suggest a 5- to 10-fold increase in MK precursors in a UCB unit can accelerate platelet engraftment, so this was our goal. Thirteen UCB samples from full-term births were Ficoll-separated and frozen for subsequent use. On thawing, the mononuclear cell population was positively selected for CD34(+) expression. The cells were cultured in gas-permeable Teflon-coated bags in serum-free medium containing the following cytokines: recombinant human interleukin-3, recombinant human Flt3 ligand, recombinant human stem cell factor, and recombinant human thrombopoietin. MK lineage cell expansion was assessed using mononuclear cell count and flow cytometry (CD34/41, CD41, CD34/61, and CD61 expression) on days 7, 11, and 14. Optimal expansion of CD34/41 and CD41 cells was observed at day 11, with a median 6-fold and 33-fold increase in the starting cell doses, respectively. CD34/61 and CD61 cell expansion at day 11 was 7-fold and 14-fold, respectively. MK precursors can be successfully expanded from CD34(+) UCB cells in a closed liquid culture system using interleukin-3, recombinant human Flt3 ligand, recombinant human stem cell factor, and recombinant human thrombopoietin to a level that should have a clinical impact in the transplantation setting. Our ex vivo expansion technique needs to be further optimized before it can be used in a pilot UCB transplantation trial.