Clinical outcomes and efficacy of stereotactic body radiation therapy in children, adolescents, and young adults with metastatic solid tumors

OBJECTIVE

The objective of this study is to report disease outcomes and toxicity with the use of stereotactic body radiation therapy (SBRT) in the treatment of pediatric metastatic disease.

METHODS

All pediatric and adolescent young adult (AYA) patients' who received SBRT were included between the years 2000 and 2020. Study endpoints included local control (LC), progression-free survival (PFS), overall survival (OS), cumulative incidence (CI) of death or local failure and toxicity. The end points with respect to survival and LC were calculated using the Kaplan-Meier estimate. The cumulative incidence of local failure was calculated using death as a competing risk.

RESULTS

16 patients with 36 lesions irradiated met inclusion criteria and formed the study cohort. The median OS and PFS for the entire cohort were 17 months and 15.7 months, respectively. The 1 year OS for the entire cohort was 75%. The 6- and 12 month local control was 85 and 78%, respectively. There were no local failures in irradiated lesions for patients who received a BED10≥100 Gy. Patients who were treated with SBRT who had ≤5 metastatic lesions at first recurrence had a superior 1 year OS of 100 vs 50% for those with >5 lesions. One patient (6.3%) experienced a Grade 3 central nervous system toxicity.

CONCLUSION

LC was excellent with SBRT delivered to metastatic disease, particularly for lesions receiving a BED10≥100 Gy. High-grade toxicity was rare in our patient population. Patients with five or fewer metastatic sites have a significantly better OS compared to >5 sites.

ADVANCES IN KNOWLEDGE

This study demonstrates that SBRT is safe and efficacious in the treatment of pediatric oligometastatic disease.

Impact of central nervous system-directed treatment on competence and adjustment among children in early cancer survivorship

BACKGROUND

Central nervous system (CNS)-directed treatments can cause long-term academic, social, and emotional difficulties for children with cancer. However, limited research has examined the emergence of problems longitudinally and has often stratified risk by diagnosis alone. Therefore, this study compared competence and adjustment in children, who did and did not receive CNS-directed treatment, over the first 3 years following a cancer diagnosis.

PROCEDURE

Mothers, fathers, and children (ages 5-18 years at diagnosis) from 217 families reported on the child's competence (academic, social) and adjustment (anxious/depressed, withdrawn/depressed) near a new cancer diagnosis or relapse and 3 years later. Children were categorized into CNS-directed treatment (n = 112; including cranial radiation, intrathecal chemotherapy, and/or neurosurgery) and non-CNS-directed treatment (n = 105) groups.

RESULTS

At enrollment, there were few differences in competence and emotional adjustment among children based on treatment or diagnostic group. At 3 years, mothers and fathers reported poorer social competence for the CNS-directed treatment group, and fathers reported poorer school competence for the CNS-directed treatment group. Over time, father ratings of social competence increased for the non-CNS-directed treatment group, but not the CNS-directed treatment group. While father ratings of academic competence declined for the CNS-directed treatment group, mother ratings declined the most for children diagnosed with a brain tumor. All children demonstrated higher anxious/depressed scores over time.

CONCLUSIONS

CNS-directed treatment may be a valuable indicator to identify childhood cancer survivors at risk for poor competence during early survivorship. Follow-up screening and supportive services are recommended, as well as additional longitudinal research.

Growing up after childhood cancer: maturity and life satisfaction in young adulthood

Purpose

Young individuals face a variety of developmental tasks as they mature into adulthood. For survivors of childhood cancer, growing up may be more difficult due to their illness and late effects from treatment. This study is the first to quantitatively examine perceptions of maturity and how these perceptions contribute to satisfaction with life among young adult survivors of childhood cancer.

Methods

Ninety survivors of childhood cancer (M_age = 29.8; 7–37 years post-diagnosis) were recruited to complete online surveys on how mature they felt relative to peers, their perceived maturity on three domains (financial, personal, social), and life satisfaction.

Results

Most survivors (62%; n = 56) felt they grew up faster than their peers, and over half (56%; n = 50) felt more mature. Perceived maturity was high on all three domains, but brain tumor survivors reported significantly lower maturity than other survivors (d = 0.76–1.11). All maturity domains were positively associated with life satisfaction (r = .49–.56). Hierarchical linear regressions indicated that 44% of the variance in life satisfaction was explained by perceptions of growing up slower (β =  − 1.08, p = .004) and marginally by greater perceived personal maturity (β = 0.45, p = .061).

Conclusions

Childhood cancer can influence development, with most survivors feeling that they grew up faster and were more mature than peers. Personal maturity was related to life satisfaction, with survivors of brain tumors or those who felt they grew up slower at greatest risk for lower life satisfaction. Future research and clinical practice should consider survivors’ development and maturation across the life span to promote overall well-being.

Excellent outcome of young children with nodular desmoplastic medulloblastoma treated on "Head Start" III: a multi-institutional, prospective clinical trial

BACKGROUND

"Head Start" III, was a prospective clinical trial using intensive induction followed by myeloablative chemotherapy and autologous hematopoietic cell rescue (AuHCR) to either avoid or reduce the dose/volume of irradiation in young children with medulloblastoma.

METHODS

Following surgery, patients received 5 cycles of induction followed by myeloablative chemotherapy using carboplatin, thiotepa, and etoposide with AuHCR. Irradiation was reserved for children >6 years old at diagnosis or with residual tumor post-induction.

RESULTS

Between 2003 and 2009, 92 children <10 years old with medulloblastoma were enrolled. Five-year event-free survival (EFS) and overall survival (OS) rates (±SE) were 46 ± 5% and 62 ± 5% for all patients, 61 ± 8% and 77 ± 7% for localized medulloblastoma, and 35 ± 7% and 52 ± 7% for disseminated patients. Nodular/desmoplastic (ND) medulloblastoma patients had 5-year EFS and OS (±SE) rates of 89 ± 6% and 89 ± 6% compared with 26 ± 6% and 53 ± 7% for classic and 38 ± 13% and 46 ± 14% for large-cell/anaplastic (LCA) medulloblastoma, respectively. In multivariate Cox regression analysis, histology was the only significant independent predictor of EFS after adjusting for stage, extent of resection, regimen, age, and sex (P <0.0001). Five-year irradiation-free EFS was 78 ± 8% for ND and 21 ± 5% for classic/LCA medulloblastoma patients. Myelosuppression was the most common toxicity, with 2 toxic deaths. Twenty-four survivors completed neurocognitive evaluation at a mean of 4.9 years post-diagnosis. IQ and memory scores were within average range overall, whereas processing speed and adaptive functioning were low-average.

CONCLUSION

We report excellent survival and preservation of mean IQ and memory for young children with ND medulloblastoma using high-dose chemotherapy, with most patients surviving without irradiation.

Impact of a Best Practice Prevention Bundle on Central Line-associated Bloodstream Infection (CLABSI) Rates and Outcomes in Pediatric Hematology, Oncology, and Hematopoietic Cell Transplantation Patients in Inpatient and Ambulatory Settings

BACKGROUND

Pediatric hematology, oncology, and hematopoietic cell transplantation (HCT) patients are at increased risk for bloodstream infections. The authors sought to evaluate the influence of a standardized best practice central venous catheter (CVC) maintenance bundle on the burden of and risk factors for mucosal barrier injury (MBI) and non-MBI central line-associated bloodstream infections (CLABSIs) across a common inpatient and ambulatory continuum in this high-risk population.

METHODS

A retrospective cohort study of patients with underlying malignancy, hematologic disorders, and HCT recipients with a CVC in place at the time of CLABSI diagnosis in both inpatient and ambulatory settings from January 1, 2012 to December 31, 2016. Descriptive, nonparametric statistics were used to describe patient characteristics and outcomes. Logistic regression analyses were applied to identify potential risk factors for inpatient versus ambulatory and MBI versus non-MBI CLABSI.

RESULTS

During the 5-year period, 118 of 808 (14.6%) patients had 159 laboratory-confirmed CLABSIs for ambulatory and inpatient CLABSI rates of 0.27 CLABSI/1000 and 2.2 CLABSI/1000 CVC days, respectively. CLABSI occurred more frequently in hospitalized patients after HCT and with underlying leukemia, most frequently caused by Gram-negative bacteria. MBI CLABSI accounted for 42% of all CLABSI with a 3-fold higher risk in hospitalized patients. Having multiple CVC or a CVC that was not a port independently associated with higher CLABSI risk.

CONCLUSIONS

In our cohort, non-MBI CLABSI continued to account for the majority of CLABSI. CVC type is independently associated with higher overall CLABSI risk. Further studies are needed to reliably define additional prevention strategies when CLABSI maintenance bundles elements are optimized in this high-risk population.

Barriers to caring for survivors of childhood cancer: Primary care providers’ and oncologists’ perspectives

e19194

Background: Advances in treatment have resulted in a growing population of childhood cancer survivors. As most survivors will develop at least one late effect from treatment, it is important to continue to monitor their health. The incidence of late effects increases with age and often are not clinically apparent until decades after cancer treatment. The Institute of Medicine has recommended models of care delivery that include collaboration between oncologists and primary care physicians (PCP). Thus, we explored PCP and pediatric oncologists’ perceptions and experiences with survivors of childhood cancer in primary care. Methods: Recruitment of primary care physicians occurred utilizing the state Board of Medicine listings. A link and a paper copy of the survey were supplied via mail to approximately 3,000 pediatricians. Pediatric oncologists from a large Midwestern hospital completed the survey via email. Results: A total of 197 participants (19 oncologists/ 178 PCPs) completed the survey. The response rate was 95% for oncologists and 6% for PCPs. Although most PCPs (76%, n=134) had cared for a childhood cancer survivor, some respondents (16%, n=8) reported an unwillingness to care for a survivor. Using a ten-point scale, PCPs mean comfort level in caring for survivors of pediatric cancer was 5.78 ( SD= 2.37). PCPs identified the following barriers: limited knowledge of late effects (64%; n=114), lack of communication with oncologist (47%; n=83), and comfort level (38%; n=67). Nearly all oncologists (86%, n=19) reported referring patients to PCPs. Oncologists typically (83%, n=15) referred patients within the first year after treatment. Overall, oncologists were comfortable referring survivors to a PCP ( M=7.5; SD=1.97) and over half were satisfied with the PCP’s care of survivors (57%, n=12). Years in practice and sex of the oncologist were unrelated to comfort level referring to PCP. Conclusions: Barriers faced by PCPs in caring for survivors illustrate a need for increased education and communication between PCPs and oncologists. Attention to these concerns may improve follow-up care and comfort in the referral process.

Primary care utilization and barriers among pediatric cancer and bone marrow transplant survivors

e22523

Background: The Institute of Medicine (IOM) report on childhood cancer survivorship specified the need to create and evaluate standards and alternative models of care delivery, including collaborative practices between oncologists and primary care physicians (PCP).1 We aimed to examine the utilization of primary care physicians by childhood cancer and bone marrow transplant (BMT) survivors, as well as identify barriers to non-oncology follow-up care. Methods: Survivors and caregivers were recruited from a cancer and bone marrow transplant survivorship clinic at a large Midwestern pediatric hospital. Participants completed a demographic survey and an 8-item semi-structured interview in clinic or online. Results: A total of 472 participants (211 survivors, 259 caregivers, 2 left unanswered) completed the survey (Survivors Mage= 26.11, SD= 7.32). Most participants were Caucasian (89%) and female (58%). Only 57 (12.3%) survivors received a BMT. There were no significant differences in PCP utilization between BMT survivors and those who did not receive a BMT, t(448) = -.519, p = .604. In addition, there were no significant group differences in PCP utilization between oncological and hematologic survivors, t(387) = 1.144, p = .253. Most survivors (87%) had a PCP, but 43% sought care for ill visits only. Survivors most commonly chose their PCP through referral from family or friends (45%), with only 4% obtaining a recommendation from their oncology provider. Top reasons for not having a PCP included being unsure who to see (52%), lack of insurance (20%), and not perceiving a need for a PCP (18%). In a logistic regression, greater annual family income ( β= .209, p< .001) and having health insurance ( β= .161, p< .01) were predictive of having a PCP. The frequency of PCP visits was also positively correlated with annual family income ( r= .13, p= .014). Conclusions: While most survivors had a PCP, higher income and insurance coverage were important predictors of having a PCP. There is a clear need for education and formal transition programs to primary care, as survivors and their family identified the need for guidance in choosing a PCP. Stronger partnerships between oncology and primary care providers may improve surveillance and outcomes for these survivors. 1. Blaauwbrock R, Zwart, N., Bouma, M., Meyboom-de Jung, B., Kamps, W., & A. Postma. The willingness of general practitioners to be involved in the follow up of adult survivors of childhood cancer. Journal of Cancer Survivors. 2007;1:292-297.

Romantic Relationships and Physical Intimacy Among Survivors of Childhood Cancer

Purpose: Childhood cancer survivors are at risk for impaired psychosocial functioning, but limited research has focused on psychosexual outcomes in young adulthood. This qualitative study examined the perceived impact of childhood cancer on adult survivors' romantic relationships and sexual/physical intimacy. Methods: Phone interviews were completed with adult survivors of childhood cancer, exploring the impact of cancer on (1) romantic relationships and (2) sexual/physical intimacy. Verbatim transcripts were coded using thematic content analysis until saturation was confirmed (n = 40). Results: Survivors in this study (n = 40) were 23-42 years old (M = 29.8; 63% female) and 10-37 years postdiagnosis (M = 18.4). Regarding romantic relationships, 60% of participants reported a negative impact, while 55% of participants reported positive effects; ∼25% of participants reported no impact of childhood cancer on adult romantic relationships. Negative themes included fertility-related concerns, physical effects (e.g., self-consciousness), feeling emotionally guarded, and delayed dating. Positive themes were creating new perspectives, increased maturity, and stronger bonds with partners. Forty percent of survivors in this study perceived having fewer partners than peers. Regarding sexual/physical intimacy, 68% of participants reported a negative impact (themes: body image, fertility-related concerns, sexual/physical dysfunction), while 33% of participants reported no effects. Conclusions: This study demonstrates both positive and negative effects of childhood cancer on adult survivors' romantic relationships, whereas effects on physical intimacy were predominantly negative. Further research is needed to inform effective psychosexual interventions, and health care providers should routinely address these topics in survivorship care.

Trajectories of health behaviors across early childhood cancer survivorship

OBJECTIVE

The majority of childhood cancer survivors develop at least one late effect subsequent to treatment (eg, cardiovascular disease and obesity). Consistent engagement in recommended health behaviors may mitigate some of these conditions. Researchers have identified early survivorship as a teachable moment, yet few studies have examined positive health behaviors during this period.

METHODS

Families of children with cancer (ages 5-17) were initially recruited following a diagnosis or relapse of cancer. Three years post diagnosis, survivors (n = 82, M_age  = 13.3, SD = 3.7) and their mothers (n = 103, M_age  = 41.1, SD = 7.6) completed a questionnaire assessing exercise, dietary, and sleep patterns among survivors. A follow-up assessment was conducted 2 years later. Mixed models tested change in health behavior over time.

RESULTS

At 3- and 5-year post diagnosis, mother and self-report indicated that few survivors engaged in appropriate levels of low-intensity exercise, fruit/vegetable intake, and dairy consumption. However, most survivors engaged in recommended levels of high intensity exercise, fast food restriction, and sleep. Health behaviors remained stable over time, except for mother report of sleep duration, which decreased (b = -0.6, P < 0.001). Brain tumor diagnosis predicted a larger decrease in self-report of sleep duration compared with other diagnoses (P = 0.04). Income predicted fast food intake such that higher income was associated with decreased intake over time, whereas lower income was associated with increased intake (P = 0.04).

CONCLUSIONS

During early survivorship, several health behaviors fell short of expectations for exercise and diet and did not improve upon reaching 5-year post diagnosis. Providers should evaluate survivors' health behaviors, including sleep, early and often, intervening when necessary.

A multiyear quality improvement project to increase influenza vaccination in a pediatric oncology population undergoing active therapy

BACKGROUND

In an effort to reduce morbidity and mortality from vaccine preventable influenza infection, national consensus guidelines recommend vaccination of patients who are immunocompromised as a result of receiving cancer therapy. Quality improvement (QI) processes are a proven method used to improve vaccination rates.

PROCEDURE

We conducted a QI initiative aimed at increasing influenza vaccination in oncology patients undergoing active treatment. Primary drivers for the project focused on patient education, staff and provider education, and communication regarding vaccine-eligible patients. We performed a retrospective analysis of influenza infection among the vaccine-eligible population. This approach has validity at our institution because of the consistent follow-up and hospital admission pattern of cancer patients on active therapy such that nearly all follow-up care is delivered at our institution.

RESULTS

We successfully achieved greater than 87% vaccination of eligible patients each vaccine season (September to March). During the recommended timeframe for delivering influenza vaccine between September and December of each vaccine season, we offered the vaccine to 100% of patients on active therapy and vaccinated >90%. Barriers to success, including vaccine refusals, increased late in the vaccine season. Influenza infection was documented in 0.5-7.3% of the vaccine-eligible group.

CONCLUSION

A robust influenza vaccination program implemented using a standardized QI approach can sustain a high vaccination rate in a pediatric oncology population receiving active treatment. The influenza infection rate was under 10% in the vaccinated group.

Family estimates of risk for neurocognitive late effects following pediatric cancer: From diagnosis through the first three years of survivorship

BACKGROUND

Families often express a need for additional information about neurocognitive late effects (NCLE) after a pediatric cancer diagnosis. Therefore, we examined: (i) differences in parent, child, and oncologist estimates of risk for NCLE; (ii) whether the estimates of parents and/or children change over time; and (iii) whether estimates are different for children treated with central nervous system (CNS) directed therapies.

PROCEDURE

Mothers, fathers, and children (initial age: 5-17, self-report: >10) from 258 families reported their perceived likelihood of the child developing "thinking/learning problems" on a visual analog scale (0-100%) at 2 months (T1), 1 year (T2), and 3 years (T3) following cancer diagnosis/relapse. Oncologists estimated the likelihood of NCLE at T1. Children were separated into groups based on CNS-directed treatment (n = 137; neurosurgery, intrathecal chemotherapy, and/or craniospinal radiation) or no CNS treatment.

RESULTS

Mother, father, and child estimates of risk for NCLE were similar to oncologists and to one another around diagnosis (T1). Although there were no significant mean differences, a considerable subset of family members either underestimated their child's risk for NCLE (>40%) or overestimated the risk for NCLE (20%) in comparison to oncologists. At T2 and T3, the estimates of mothers were significantly higher than children. Linear growth curves indicated that mothers' estimates for children with CNS-directed treatment significantly increased throughout the first 3 years of survivorship.

CONCLUSIONS

Considering that accurate understanding of NCLE is essential to seeking appropriate assessment and intervention, healthcare providers should focus on implementing family-based education early in treatment and throughout survivorship care.

Psychosexual development and satisfaction in long-term survivors of childhood cancer: Neurotoxic treatment intensity as a risk indicator

BACKGROUND

Risk factors for impairment in psychosexual development and satisfaction among adult survivors of childhood cancer are poorly understood. The authors compared psychosexual outcomes between survivors and healthy controls, and tested whether at-risk survivors can be identified by 1) treatment neurotoxicity or 2) diagnosis.

METHODS

A total of 144 young adult survivors of childhood cancer and 144 matched controls completed questionnaires regarding psychosexual development, sexual satisfaction, and satisfaction with relationship status. Survivors were aged 20 to 40 years and were 5 to 34 years after diagnosis. Using medical chart data, survivors were divided into non-neurotoxic (48 survivors), low-dose (36 survivors), and high-dose (58 survivors) neurotoxic treatment groups.

RESULTS

Apart from having fewer lifetime sex partners, survivors did not appear to differ from controls. However, survivors of brain tumors and any survivor who received high-dose neurotoxic treatment reported the lowest rates of achieving milestones of psychosexual development, whereas sexual and relationship status satisfaction were found to be related to relationship status. Neurotoxic treatment intensity further distinguished between survivors of brain tumors with and without psychosexual impairment.

CONCLUSIONS

The intensity of neurotoxic treatment may be a valuable indicator of risk for psychosexual impairment relative to diagnosis alone. Health care providers should assess romantic/sexual problems among survivors at risk and make referrals if needed. Cancer 2017;123:1869-1876. © 2017 American Cancer Society.

Body issues, sexual satisfaction, and relationship status satisfaction in long-term childhood cancer survivors and healthy controls

OBJECTIVE

Research on body image and sexual satisfaction after adult onset cancer has shown significant and lasting impairments regarding survivors' sexuality and romantic relationships. However, knowledge about these topics and their associations in adult survivors of childhood cancer is largely lacking.

METHODS

Participants completed web-based questionnaires concerning body image, body dissociation, sexual satisfaction, and relationship status satisfaction (i.e., satisfaction with either being in a relationship or being single). Survivors (n = 87) and controls (n = 87) were matched on age and gender, with a mean age of 27 years (range: 20-40). Survivors were most often diagnosed with leukemia (46%), at an average of 16 years prior to study participation (range: 6-33 years).

RESULTS

Similar numbers of survivors and controls were single (n = 24/31), in a committed relationship (n = 33/23), or married (n = 30/33). Survivors and controls reported comparable levels of body image, body dissociation, sexual experiences, and sexual and status satisfaction (d = 0.15-0.28). Higher status satisfaction was associated with being in a relationship (compared with being single, β = 0.439), more positive body image (β = 0.196), and higher sexual satisfaction (β = 0.200).

CONCLUSIONS

Adult survivors of childhood cancer were comparable to healthy peers regarding views of their bodies and psychosexual development, which was unexpected. Independent of whether people experienced cancer or not, their status satisfaction was associated with their relationship status, body image, and sexual satisfaction. Future research should explore why sexual and body problems are identified after adult onset cancer, whereas this seems to be less of a problem in childhood cancer survivors.

A multi-institutional experience in pediatric high-grade glioma

INTRODUCTION

Pediatric high-grade gliomas are rare tumors with poor outcomes and incompletely defined management. We conducted a multi-institutional retrospective study to evaluate association of clinical, pathologic, and treatment characteristics with outcomes.

MATERIALS AND METHODS

Fifty-one patients treated from 1984 to 2008 at the Ohio State University or University of Michigan were included. Histologic subgroups were compared. Log-rank and stepwise Cox proportional hazard modeling were used to analyze progression-free survival (PFS) and overall survival (OS) within the whole group, grade III subgroup, grade IV subgroup, and sub-total resection/biopsy subgroup.

RESULTS

Median OS was 27.6 months. Grade III histology, complete tumor resection, and cerebral tumor location correlated with improved PFS and OS. Temozolomide use and chemotherapy after radiotherapy or chemoradiation (CRT) were associated with better PFS while seizure at presentation was associated with better OS. In multivariate analysis, complete resection and chemotherapy following radiotherapy or CRT were independent predictors for improved PFS and OS. For grade III and IV subgroups, complete resection was associated with improved OS (grade III) and seizure presentation was associated with improved OS (grade IV). In the incompletely resection subgroup, temozolomide use and concurrent CRT independently correlated with improved PFS, while higher radiation dose (≥59.4 Gy) and adjuvant chemotherapy were independently associated with improved OS.

DISCUSSION

Total resection and receiving chemotherapy adjuvant to radiation or CRT are most closely associated with improved PFS and OS. For higher risk incompletely resected patients, temozolomide use and treatment intensification with concurrent CRT, adjuvant chemotherapy, and higher radiation dose were associated with improved outcomes.

Nuclear expression of Survivin in paediatric ependymomas and choroid plexus tumours correlates with morphologic tumour grade

Survivin is a gene that is widely expressed throughout the development of the normal mammalian embryo. Subcellular localisation of Survivin to both the nucleus and cytoplasm has suggested multiple functional roles, including inhibition of cell death, especially as demonstrated within a variety of malignant cell types, as well as regulation of the mitotic spindle checkpoint. The expression of Survivin has been associated with an adverse clinical outcome in a large number of malignancies. However, nuclear Survivin expression has been described as an independent variable of favourable prognosis in two large clinical studies of breast and gastric carcinomas. Reports of Survivin expression in normal postnatal, differentiated tissues have been restricted to cell types with high proliferative capacities, including vascular endothelium, endometrium, colonic epithelium, and activated lymphocytes. Prior to this report, expression within the normal human brain had not been characterised. Here, we analyse the expression of Survivin in human brain sections obtained from perinatal and paediatric autopsy cases. We report a strikingly high level of expression of Survivin within normal ependyma and choroid plexus (CP). Analysis of corresponding neoplastic tissue in paediatric ependymomas and CP tumours shows that expression of the nuclear form of Survivin correlates with morphologic tumour grade, with a loss of nuclear expression associated with progressive cytologic anaplasia. This pattern of expression supports a hypothesis that Survivin plays a functional role in normal ependymal growth and/or neural stem cell differentiation, and that abnormally low levels of expression of the nuclear form of this protein may be a marker of more aggressive disease and/or higher morphologic grade in ependymal and CP tumours.

Coincidence FDG-PET in the evaluation of Langerhans' cell histiocytosis: preliminary findings

BACKGROUND

Bone involvement in Langerhans' cell histiocytosis (LCH) is common. Both bone scintigraphy and plain films are used to identify osseous lesions, but lack specificity for disease activity and response to therapy. FDG-PET is a sensitive technique for identifying bone lesions when histiocytes are present. OBJECTIVE. To describe the potential of coincidence FDG-PET (cFDG-PET) for identification of active bone lesions in LCH and to determine whether it can provide more specific information regarding lesional response to therapy than bone scintigraphy or radiography.

MATERIALS AND METHODS

The clinical data and imaging findings of three patients with osseous lesions of LCH were retrospectively reviewed.

RESULTS

cFDG-PET identified all active LCH osseous lesions in these patients, differentiated active from healed lesions, and demonstrated normalization of uptake in a treated lesion earlier than bone scintigraphy and radiography.

CONCLUSION

cFDG-PET appears to have greater specificity than bone scintigraphy and radiography for the identification of active osseous lesions in LCH. It also may predict response to treatment earlier than conventional techniques. Its use in the evaluation of LCH warrants further study.

Glucosylceramide synthase inhibition enhances vincristine-induced cytotoxicity

As a strategy to enhance tumor cell sensitivity to vincristine, we tested whether modulation of sphingolipid metabolism would alter vincristine cytotoxicity since this is linked to accumulation of the intermediate metabolite, ceramide. We blocked ceramide metabolism in a series of variably vincristine-resistant cell lines derived from CCRF-CEM leukemia cells using an inhibitor of glucosylceramide synthase, DL-threo-phenyl-2-hexadecanoylamino-3-pyrrolidino-1-propanol (PPPP). PPPP alone (1.0 microM), while nearly completely blocking glucosylceramide synthesis, was not toxic and did not increase cellular ceramide levels. Vincristine alone was toxic, caused apoptosis or programmed cell death (PCD) and caused an elevation in ceramide levels. Strikingly, the combination of PPPP and vincristine resulted in a further increase, over that of vincristine alone, of (i) cellular ceramide concentration, (ii) cytotoxicity associated with PCD and (iii) G2/M cell-cycle arrest. PPPP had no effect on P-glycoprotein expression or function. We conclude that vincristine cytotoxicity occurs in part through a ceramide-dependent mechanism, resulting in both G2/M block as well as PCD, and that the blockade of glucosylceramide synthase, in itself not toxic, causes augmented accumulation of ceramide resulting from vincristine exposure, which in turn maximizes ceramide-dependent, vincristine-induced cytotoxicity. Inhibition of glucosylceramide synthesis may be a means of circumventing drug resistance by enhancing signaling through a cell-death pathway.

Syncope associated with concurrent amitriptyline and fluconazole therapy

OBJECTIVE

To report on a 12-year-old white male with prostatic rhabdomyosarcoma who experienced episodes of syncope attributed to concurrent amitriptyline and fluconazole therapy, confirmed by readministration.

CASE REPORT

The patient began experiencing syncopal episodes periodically over a seven-month period. These repeated episodes occurred when fluconazole was administered for periodic mucositis secondary to chemotherapy. The patient had received fluconazole in the past with no difficulty and had been receiving a stable dose of amitriptyline for neuropathic pain. On discontinuation of amitriptyline, no further episodes were noted.

DISCUSSION

Concurrent administration of fluconazole with amitriptyline likely resulted in the decreased metabolism of amitriptytine. Three case reports presented in the literature of adults receiving concurrent amitriptyline and fluconazole have shown an increase in serum amitriptyline concentrations with concurrent administration of fluconazole; however, none of these patients were rechallenged. Literature available on amitriptyline overdose confirms that syncope and the adverse events noted in the case studies may result from elevated amitriptyline plasma concentrations.

CONCLUSIONS

The consistent presentation of syncope in our patient during readministration of amitriptytine and fluconazole strongly suggests a drug-drug interaction.

Correlation of P-glycoprotein expression and function in childhood acute leukemia: a children's cancer group study

Clinical drug resistance may be attributed to the simultaneous selection and expression of genes modulating the uptake and metabolism of chemotherapeutic agents. P-glycoprotein (P-gp) functions as a membrane-associated drug efflux pump whose increased expression results in resistance to anthracyclines, epipodophyllotoxins, vinca alkaloids, and some alkylating agents. This type of resistance occurs as both de novo and acquired resistance to therapy for leukemia. We have studied P-gp expression and function in childhood acute leukemias by developing a series of doxorubicin- and vincristine-selected CEM, T-cell lymphoblastoid cell lines that recapitulate the low levels of expression and resistance seen clinically. These cell lines have been used to develop flow cytometric assays for the semiquantitative measurements of P-gp expression with the MRK16 monoclonal antibody and P-gp function using the enhanced retention of rhodamine 123 in the presence of verapamil, a resistance modulator. Kolmogorov-Smirnov statistics, represented by the D measurement, are used to determine the difference in level of P-gp expression by comparing MRK16 staining to an IgG2a isotype control. When D is > 0.09, there is an excellent correlation (R = 0.82) between P-gp expression and function. The evaluation of 107 bone marrow specimens from 84 children with lymphoblastic or myelogenous leukemia showed a statistically significant (P = .004) increase in P-gp function at relapse. P-gp expression at relapse, however, approached but did not reach a significant level (P = .097). Using this methodology, we can identify patients with levels of P-gp expression and function that we can define clinically, as well as children with discordant multidrug resistance phenotypes. This study supports the role of P-gp-mediated drug resistance in childhood leukemia and confirms that P-gp expression and function are measurable in their leukemic blasts. These assays provide the means for the in vitro testing of resistance modulators and the monitoring of in vivo response to treatment with these agents.