Comparative effectiveness of Denosumab vs alendronate among postmenopausal women with osteoporosis

Although clinical trials have shown that denosumab significantly increases bone mineral density at key skeletal sites more than oral bisphosphonates, evidence is lacking from head-to-head randomized trials evaluating fracture outcomes. This retrospective cohort study uses administrative claims data from Medicare fee-for service beneficiaries to evaluate the comparative effectiveness of denosumab versus alendronate in reducing fracture risk among women with postmenopausal osteoporosis (PMO) in the US. Women with PMO ≥ 66 years of age with no prior history of osteoporosis treatment, who initiated denosumab (n = 89 115) or alendronate (n = 389 536) from 2012 to 2018, were followed from treatment initiation until the first of a specific fracture outcome, treatment discontinuation or switch, end of study (December 31, 2019), or other censoring criteria. A doubly robust inverse-probability of treatment and censoring weighted function was used to estimate the risk ratio associated with the use of denosumab compared with alendronate for hip, nonvertebral (NV; includes hip, humerus, pelvis, radius/ulna, other femur), non-hip nonvertebral (NHNV), hospitalized vertebral (HV), and major osteoporotic (MOP; consisting of NV and HV) fractures. Overall, denosumab reduced the risk of MOP by 39%, hip by 36%, NV by 43%, NHNV by 50%, and HV fractures by 30% compared with alendronate. Denosumab reduced the risk of MOP fractures by 9% at year 1, 12% at year 2, 18% at year 3, and 31% at year 5. An increase in the magnitude of fracture risk reduction with increasing duration of exposure was also observed for other NV fracture outcomes. In this cohort of almost half-a-million treatment-naive women with PMO, we observed clinically significant reductions in the risk of MOP, hip, NV, NHNV, and HV fractures for patients on denosumab compared with alendronate. Patients who remained on denosumab for longer periods of time experienced greater reductions in fracture risk.

Economic and Humanistic Burden Among Medicare-Aged Women With Fragility Fracture in the United States

OBJECTIVE

Describe patient characteristics, health care resource utilization, costs, and humanistic burden of women with Medicare insurance with incident fragility fracture who were admitted to post-acute-care (PAC).

DESIGN

Retrospective cohort study using 100% Medicare Fee-for-Service (FFS) data.

SETTING AND PARTICIPANTS

Community-dwelling female Medicare beneficiaries with incident fragility fracture January 1, 2017, to October 17, 2019, resulting in PAC admission to a skilled nursing facility (SNF), home-health care, inpatient-rehabilitation facility, or long-term acute-care hospital.

METHODS

Patient demographic/clinical characteristics were measured during 1-year baseline. Resource utilization and costs were measured during baseline, PAC event, and PAC follow-up. Humanistic burden was measured among SNF patients with linked Minimum Data Set assessments. Multivariable regression examined predictors of PAC costs after discharge and changes in functional status during SNF stay.

RESULTS

A total of 388,732 patients were included. Compared with baseline, hospitalization rates were 3.5, 2.4, 2.6, and 3.1 times higher and total costs 2.7, 2.0, 2.5, and 3.6 times higher for SNF, home-health, inpatient-rehabilitation, and long-term acute-care, respectively, following PAC discharge. Utilization of dual-energy X-ray absorptiometry (DXA) and osteoporosis medications remained low: 8.5% to 13.7% received DXA during baseline vs 5.2% to 15.6% following PAC; 10.2% to 12.0% received osteoporosis medication during baseline vs 11.4% to 22.3% following PAC. Dual eligibility for Medicaid (ie, low income) was associated with 12% higher costs; Black patients had 14% higher costs. Activities of daily living scores improved 3.5 points during SNF stay, but Black patients had 1.22-point lower improvement than White patients. Pain intensity scores showed small improvement (-0.8 points).

CONCLUSIONS AND IMPLICATIONS

Women admitted to PAC with incident fracture had high humanistic burden with little improvement in pain and functional status and significantly higher economic burden after discharge compared with baseline. Disparities in outcomes related to social risk factors were observed, with consistently low utilization of DXA and osteoporosis medications even after fracture. Results indicate a need for improved early diagnosis and aggressive disease management to prevent and treat fragility fractures.

Treatment rates and healthcare costs of patients with fragility fracture by site of care: a real-world data analysis

In a characterization of treatment rates and healthcare costs among patients with an osteoporotic-related fragility fracture overall and by site of care, costs were high and treatment rates were low.

PURPOSE

Osteoporotic fractures can be debilitating, even fatal, among older adults. The cost of osteoporosis and related fractures is projected to increase to more than $25 billion by 2025. The objective of this analysis is to characterize disease-related treatment rates and healthcare costs of patients with an osteoporotic fragility fracture overall and by site of fracture diagnosis.

METHODS

In this retrospective analysis, individuals with fragility fractures were identified in the Merative MarketScan® Commercial and Medicare Databases among women 50 years of age or older and diagnosed with fragility fracture between 1/1/2013 and 6/30/2018 (earliest fracture diagnosis = index). Cohorts were categorized by clinical site of care where the diagnosis of fragility fracture was made and were continuously followed for 12 months prior to and following index. Sites of care were inpatient admission, outpatient office, outpatient hospital, emergency room hospital, and urgent care.

RESULTS

Of the 108,965 eligible patients with fragility fracture (mean age 68.8), most were diagnosed during an inpatient admission or outpatient office visit (42.7%, 31.9%). The mean annual healthcare costs among patients with fragility fracture were $44,311 (± $67,427) and were highest for those diagnosed in an inpatient setting ($71,561 ± $84,072). Compared with other sites of care at fracture diagnosis, patients diagnosed during an inpatient admission also had highest proportion of subsequent fractures (33.2%), osteoporosis diagnosis (27.7%), and osteoporosis therapy (17.2%) during follow-up.

CONCLUSION

The site of care for diagnosis of fragility fracture affects treatment rates and healthcare costs. Further studies are needed to determine how attitude or knowledge about osteoporosis treatment or healthcare experiences differ at various clinical sites of care in the medical management of osteoporosis.

Long-term effect of denosumab on bone microarchitecture as assessed by tissue thickness-adjusted trabecular bone score in postmenopausal women with osteoporosis: results from FREEDOM and its open-label extension

In postmenopausal women with osteoporosis, up to 10 years of denosumab treatment significantly and continuously improved bone microarchitecture assessed by tissue thickness-adjusted trabecular bone score, independently of bone mineral density. Long-term denosumab treatment decreased the number of high fracture-risk patients and shifted more patients to lower fracture-risk categories.

PURPOSE

To investigate the long-term effect of denosumab on bone microarchitecture assessed by tissue thickness-adjusted trabecular bone score (TBS_TT) in post-hoc subgroup analysis of FREEDOM and open-label extension (OLE).

METHODS

Postmenopausal women with lumbar spine (LS) or total hip BMD T-score <-2.5 and ≥-4.0 who completed the FREEDOM DXA substudy and continued in OLE were included. Patients received either denosumab 60 mg subcutaneously every 6 months for 3 years and same-dose open-label denosumab for 7 years (long-term denosumab; n=150) or placebo for 3 years and open-label denosumab for 7 years (crossover denosumab; n=129). BMD and TBS_TT were assessed on LS DXA scans at FREEDOM baseline, month 1, and years 1-6, 8, and 10.

RESULTS

In long-term denosumab group, continued increases from baseline to years 4, 5, 6, 8, and 10 in BMD (11.6%, 13.7%, 15.5%, 18.5%, and 22.4%) and TBS_TT (3.2%, 2.9%, 4.1%, 3.6%, and 4.7%) were observed (all P < 0.0001). Long-term denosumab treatment decreased the proportion of patients at high fracture-risk (according to TBS_TT and BMD T-score) from baseline up to year 10 (93.7 to 40.4%), resulting in increases in the proportions at medium-risk (6.3 to 53.9%) and low-risk (0 to 5.7%) (P < 0.0001). Similar responses were observed in crossover denosumab group. Changes in BMD and TBS_TT were poorly correlated during denosumab treatment.

CONCLUSION

In postmenopausal women with osteoporosis, up to 10 years of denosumab significantly and continuously improved bone microarchitecture assessed by TBS_TT, independently of BMD, and shifted more patients to lower fracture-risk categories.

Updated trabecular bone score accounting for the soft tissue thickness (TBSTT) demonstrated significantly improved bone microstructure with denosumab in the FREEDOM TBS post hoc analysis

TBS algorithm has been updated to account for regional soft tissue noise. In postmenopausal women with osteoporosis, denosumab improved tissue thickness-adjusted TBS vs placebo independently of bone mineral density over 3 years, with the magnitude of changes from baseline or placebo numerically greater than body mass index-adjusted TBS.

INTRODUCTION

To evaluate the effect of denosumab on bone microarchitecture assessed by trabecular bone score (TBS) in the FREEDOM study using the updated algorithm that accounts for regional soft tissue thickness (TBS_TT) in dual-energy X-ray absorptiometry (DXA) images and to compare percent changes from baseline and placebo with classical body mass index (BMI)-adjusted TBS (TBS_BMI).

METHODS

Postmenopausal women with lumbar spine or total hip bone mineral density (BMD) T score <  - 2.5 and ≥  - 4.0 received placebo or denosumab 60 mg subcutaneously every 6 months. TBS_BMI and TBS_TT were assessed on lumbar spine DXA scans at baseline and months 1, 12, 24, and 36 in a subset of 279 women (129 placebo, 150 denosumab) who completed the 3-year FREEDOM DXA substudy and rolled over to open-label extension study.

RESULTS

Baseline characteristics were similar between groups. TBS_TT in the denosumab group showed numerically greater changes from both baseline and placebo than TBS_BMI at months 12, 24, and 36. Denosumab led to progressive increases in BMD (1.2, 5.6, 8.1, and 10.5%) and TBS_TT (0.4, 2.3, 2.6, and 3.3%) from baseline to months 1, 12, 24, and 36, respectively. Both TBS changes were significant vs baseline and placebo from months 12 to 36 (p < 0.0001). As expected, BMD and TBS_TT were poorly correlated both at baseline and for changes during treatment.

CONCLUSION

In postmenopausal women with osteoporosis, denosumab significantly improved bone microstructure assessed by TBS_TT over 3 years. TBS_TT seemed more responsive to denosumab treatment than TBS_BMI and was independent of BMD.

Multiple Vertebral Fractures After Denosumab Discontinuation: FREEDOM and FREEDOM Extension Trials Additional Post Hoc Analyses

It is uncertain whether the risk of vertebral fracture (VF) and multiple vertebral fractures (MVFs; ≥2 VFs) after denosumab (DMAb) discontinuation is related to treatment duration. A prior analysis of Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM) and FREEDOM Extension trials did not find a relationship with DMAb duration and may have underreported MVF incidence because it included women who did not have radiographs. In this post hoc exploratory analysis, the crude incidence and annualized rates of VF and MVF were determined in patients with ≥7 months' follow-up and ≥1 spine radiograph after discontinuing placebo or DMAb. A multivariate analysis was performed to identify predictors of MVF. Clinical characteristics of patients with ≥4 VFs were explored. This analysis included women who discontinued after placebo (n = 327) or DMAb either from FREEDOM or FREEDOM Extension (n = 425). The DMAb discontinuation group was subsequently dichotomized by treatment duration: short-term (≤3 years; n = 262) and long-term (>3 years; n = 213) treatment. For any VF, exposure-adjusted annualized rates per 100 patient-years (95% confidence interval [CI]) were 9.4 (95% CI, 6.4-13.4) for placebo, 6.7 (95% CI, 4.2-10.1) for short-term DMAb, and 10.7 (95% CI, 7.4-15) for long-term DMAb. Annualized rates for MVF were 3.6 (95% CI, 1.9-6.3), 2.9 (95% CI, 1.4-5.4), and 7.5 (95% CI, 4.8-11.1), respectively. Annualized rates for ≥4 VFs were 0.59 (95% CI, 0.1-2.1), 0.57 (95% CI, 0.1-2.1), and 3.34 (95% CI, 1.7-6.0), respectively. In a multivariate regression model, DMAb duration was significantly associated with MVF risk (odds ratio 3.0; 95% CI, 1.4-6.5). Of 15 patients with ≥4 VFs, 13 had DMAb exposure (mean ± standard deviation [SD], 4.9 ± 2.2 years). The risk of MVF after DMAb discontinuation increases with increased duration of DMAb treatment. Patients transitioning off DMAb after 3 years may warrant more frequent administration of zoledronic acid or another bisphosphonate to maintain bone turnover and bone mineral density (BMD) and prevent MVF. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Romosozumab and antiresorptive treatment: the importance of treatment sequence

To evaluate whether treatment sequence affects romosozumab response, this analysis reviewed studies where romosozumab was administered before or following an antiresorptive (alendronate or denosumab). Initial treatment with romosozumab followed by an antiresorptive resulted in larger increases in bone mineral density of both hip and spine compared with the reverse sequence.

INTRODUCTION

Teriparatide followed by an antiresorptive increases bone mineral density (BMD) more than using an antiresorptive first. To evaluate whether treatment sequence affects romosozumab response, we reviewed randomized clinical trials where romosozumab was administered before (ARCH, FRAME) or following (STRUCTURE, Phase 2 extension) an antiresorptive (alendronate or denosumab, respectively).

METHODS

We evaluated BMD percentage change for total hip (TH) and lumbar spine (LS) and response rates (BMD gains ≥ 3% and ≥ 6%) at years 1 and 2 (except STRUCTURE with only 1-year data available).

RESULTS

With 1-year romosozumab initial therapy in ARCH and FRAME, TH BMD increased 6.2% and 6.0%, and LS BMD increased 13.7% and 13.1%, respectively. When romosozumab was administered for 1 year after alendronate (STRUCTURE) or denosumab (Phase 2 extension), TH BMD increased 2.9% and 0.9%, respectively, and LS BMD increased 9.8% and 5.3%, respectively. Over 2 years, TH and LS BMD increased 7.1% and 15.2% with romosozumab/alendronate, 8.5% and 16.6% with romosozumab/denosumab, and 3.8% and 11.5% with denosumab/romosozumab, respectively. A greater proportion of patients achieved BMD gains ≥ 6% when romosozumab was used first, particularly for TH, versus the reverse sequence (69% after romosozumab/denosumab; 15% after denosumab/romosozumab).

CONCLUSION

In this study, larger mean BMD increases and greater BMD responder rates were achieved when romosozumab was used before, versus after, an antiresorptive agent. Since BMD on treatment is a strong surrogate for bone strength and fracture risk, this analysis supports the thesis that initial treatment with romosozumab followed by an antiresorptive will result in greater efficacy versus the reverse sequence.

Long-term direct and indirect economic burden associated with osteoporotic fracture in US postmenopausal women

The study examined long-term direct and indirect economic burden of osteoporotic fractures among postmenopausal women. Healthcare costs among fracture patients were substantial in first year after fracture and remained higher than fracture-free controls for 5 years which highlight needs for early detection of high-risk patients and continued management for osteoporosis.

INTRODUCTION

This study compared direct and indirect healthcare costs between postmenopausal women and demographically matched controls in the 5 years after incident non-traumatic fracture, and by fracture type in commercially insured and Medicare populations.

METHODS

Two hundred twenty-six thousand one hundred ninety women (91,925 aged 50-64 years; 134,265 aged ≥ 65 years) with incident non-traumatic fracture (hip, vertebral, and non-hip non-vertebral (NHNV)) from 2008 to 2017 were identified. Patients with fracture were directly matched (1:1) to non-fracture controls based on demographic characteristics. Direct healthcare costs were assessed using general linear models, adjusting for baseline costs, comorbidities, osteoporosis diagnosis, and treatment. Indirect costs associated with work loss due to absenteeism and short-term disability (STD) were assessed among commercially insured patients. Costs were standardized to 2019 US dollars.

RESULTS

Osteoporosis diagnosis and treatment rates prior to fracture were low. Patients with fracture incurred higher direct costs across 5-year post-index compared with non-fracture controls, regardless of fracture type or insurance. For commercially insured hip fracture patients, the mean adjusted incremental direct healthcare costs in years 1, 3, and 5 were $59,327, $6885, and $3241, respectively. Incremental costs were lower, but trends were similar for vertebral and NHNV fracture types and Medicare-insured patients. Commercially insured patients with fracture had higher unadjusted indirect costs due to absenteeism and STD in year 1 and higher adjusted indirect costs due to STD at year 1 (incremental cost $5848, $2748, and $2596 for hip, vertebral, and NHNV fracture).

CONCLUSIONS

A considerable and sustained economic burden after a non-traumatic fracture underscores the need for early patient identification and continued management.

Leptomeningeal Relapse of Embryonal Rhabdomyosarcoma after 15 years

Aim Rhabdomyosarcoma (RMS) is the most common malignant soft tissue tumour of childhood. We present the case of a late relapse of RMS to the leptomeninges after 15 years. Methods A 20 year old male presented with a 3 week history of headaches and nausea. He previously had RMS of his right ear diagnosed at age 5 years which was treated with concurrent chemoradiotherapy. An MRI Brain and Spine confirmed extensive leptomeningeal disease and CSF analysis confirmed the presence of recurrent embryonal RMS. Results He completed two cycles of cyclophosphamide and topotecan followed by 45Gy/25Fr of craniospinal radiotherapy. Conclusion Late relapses beyond five years can be seen in up to 9% of patients, however very late recurrences (>10 years) are exceedingly rare. Molecular based methods such as gene expression profiling can aid risk stratification and survivorship clinics may become increasingly useful in following patients with high risk features.

A Pooled Analysis of Fall Incidence From Placebo-Controlled Trials of Denosumab

Recent studies suggest that the RANK/RANKL system impacts muscle function and/or mass. In the pivotal placebo-controlled fracture trial of the RANKL inhibitor denosumab in women with postmenopausal osteoporosis, treatment was associated with a lower incidence of non-fracture-related falls (p = 0.02). This ad hoc exploratory analysis pooled data from five placebo-controlled trials of denosumab to determine consistency across trials, if any, of the reduction of fall incidence. The analysis included trials in women with postmenopausal osteoporosis and low bone mass, men with osteoporosis, women receiving adjuvant aromatase inhibitors for breast cancer, and men receiving androgen deprivation therapy for prostate cancer. The analysis was stratified by trial, and only included data from the placebo-controlled period of each trial. A time-to-event analysis of first fall and exposure-adjusted subject incidence rates of falls were analyzed. Falls were reported and captured as adverse events. The analysis comprised 10,036 individuals; 5030 received denosumab 60 mg subcutaneously once every 6 months for 12 to 36 months and 5006 received placebo. Kaplan-Meier estimates showed an occurrence of falls in 6.5% of subjects in the placebo group compared with 5.2% of subjects in the denosumab group (hazard ratio = 0.79; 95% confidence interval 0.66-0.93; p = 0.0061). Heterogeneity in study designs did not permit overall assessment of association with fracture outcomes. In conclusion, denosumab may reduce the risk of falls in addition to its established fracture risk reduction by reducing bone resorption and increasing bone mass. These observations require further exploration and confirmation in studies with muscle function or falls as the primary outcome. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research..

SUN-389 Trends in Osteoporosis Treatment Uptake and Persistence Among Postmenopausal Women in the U.S., 2010–2015

Background: Over the last several years, the approval of new pharmacotherapies, changes to health plan formularies limiting treatment access, the emergence of new evidence related to medication safety and effectiveness, and updates to clinical practice guidelines may have influenced osteoporosis treatment patterns. Sankey visualizations were used to depict postmenopausal (PM) women’s osteoporosis treatment journeys, from treatment uptake, patterns of transition, to persistence. Methods: We conducted a retrospective analysis of all PM women (aged 55+) who newly initiated five antiresorptive treatments between October 1, 2010 and September 30, 2015 using patient and prescription data from the Truven Health Analytics MarketScan Commercial Claims and Encounters and Medicare Supplemental databases. We identified women who were continuously enrolled in the health plan for one year prior to the date of treatment initiation (index date) and were treatment-free during this period. Treatment states were evaluated cross-sectionally at six-month time points; treatment switches and gaps in therapy between time points were not captured. Persistence was defined as a patient being on the same treatment at a given follow-up time point as compared to the treatment they were on at the index date. Results: Among women newly initiating any of the five antiresorptive therapies, alendronate (53%) remained the most commonly prescribed therapy, followed by ibandronate (13 %), zoledronic acid-ZA (12%), risedronate (11 %), and denosumab (11%). New initiation of alendronate was high across all age, prior fracture history, and osteoporosis diagnosis subgroups (range: 45–68%). From 2010 to 2015, new uptake of denosumab increased by 13%, while ZA uptake declined by 10%. A higher proportion of denosumab users were ≥ 65 years (denosumab: 59%; ZA: 54%; alendronate: 46%) and had a prior history of fracture (denosumab: 30%, ZA: 25%; alendronate: 19%) compared to bisphosphonate users. Two-year persistence was highest among women initiating denosumab (58%), followed by ZA (48%), alendronate (32%), ibandronate (30%), and risedronate (25%). Persistence was lowest for oral bisphosphonate users (alendronate range: 30–33%), irregular among ZA users (range: 29–49%) and higher for denosumab users across all subgroups (range: 46–59%). From 2010 to 2014, persistence improved for all therapies, except among ZA users, which declined by 9%. Conclusions: Little has changed in the prescribing patterns and patient profiles of PM women newly initiating antiresorptive therapies over five years from 2010–2015. Alendronate remained the most commonly prescribed therapy despite lower rates of persistence, with similarly high uptake regardless of risk for fracture. Denosumab was primarily prescribed to women at higher risk for fracture, and persistence was higher compared to other therapies across all subgroups.

Estimation of Long-Term Efficacy of Denosumab Treatment in Postmenopausal Women With Osteoporosis: A FRAX- and Virtual Twin-Based Post Hoc Analysis From the FREEDOM and FREEDOM Extension Trials

The 3-year placebo-controlled FREEDOM (Fracture REduction Evaluation of Denosumab in Osteoporosis Every 6 Months) trial established the antifracture efficacy of denosumab in postmenopausal women with osteoporosis. The 7-year open-label extension demonstrated that denosumab treatment for up to 10 years was associated with low rates of adverse events and low fracture incidence. The extension lacked a long-term control group, thus limiting the ability to fully evaluate long-term efficacy. This analysis provides a quantitative estimate of the long-term antifracture efficacy of denosumab based on two approaches: comparison with FRAX®- (Fracture Risk Assessment Tool-) and virtual twin-estimated 10-year fracture rates. Subjects who were randomized to denosumab in the FREEDOM trial, continued into the Extension study, completed the 10-year visit, and missed ≤1 dose in the FREEDOM trial and ≤1 dose in the Extension (n = 1278) were included in the analysis. The 10-year observed cumulative incidence of major osteoporotic fracture (MOF) and hip fractures was compared with the 10-year fracture probability predicted at baseline by FRAX, a computer-based fracture risk algorithm, and with that estimated for a hypothetical cohort of 10-year placebo controls (virtual twins). The observed 10-year fracture incidence was lower than the 10-year probability predicted by FRAX for both MOF (10.75% [95% CI, 9.05 to 12.46] versus 15.63% [95% CI, 15.08 to 16.18], respectively), and hip fractures (1.17% [95% CI, 0.58 to 1.76] versus 5.62% [95% CI, 5.28 to 5.97], respectively). The observed fracture incidence was also lower than the fracture rate estimated in a hypothetical cohort of 10-year placebo controls for MOF (23.13% [95% CI, 17.76 to 28.87]; relative risk 0.49 [95% CI, 0.36 to 0.64]). These data support the long-term efficacy of denosumab in reducing MOF and hip fractures in postmenopausal women with osteoporosis. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Burkitt Lymphoma/Leukaemia in Children & Young Adolescents

Aims Burkitt Lymphoma (BL) accounts for approximately 40% of childhood non-Hodgkin Lymphoma (NHL) in the developed world. Survival rates have improved dramatically in recent years, a success attributed to better use of poly-chemotherapy and targeted immunotherapy. Nevertheless, relapse is unpredictable and carries a dismal prognosis. We report on event-free survival (EFS) and overall survival (OS) rates in the Republic of Ireland (ROI) during 2000-2017, and evaluate novel predictors of outcome. Methods Data was collected by retrospective review of patient medical records. Results Thirty-three patients were identified (twenty-five [76%] males, eight [24%] females), fourteen [42%] having stage III disease at presentation. Six [18%] had stage IV disease. Five [15%] had refractory disease; one salvaged with allogeneic stem cell transplantation. Of the four [12%] who died; two [50%] had weights >99th centile, one [25%] >90th centile. One died during induction from refractory lactic acidosis, one from early relapse. Discussion EFS and OS was 85% and 89% respectively; in keeping with the best international standards. Obesity appears to be a poor predictor of outcome in our cohort.

Abstract P6-17-11: The small molecule inhibitor of HER2, tucatinib, has potent and highly selective activity in preclinical modes of HER2-driven cancer

Background: Pharmacologically targeting the HER2 oncoprotein provides clinical benefit for patients with HER2-amplified cancers. However, a significant number of patients do not respond to the currently approved HER2-targeted therapies, despite carrying the HER2-alteration. Small molecule inhibitors of HER2, that target other receptor tyrosine kinases such as EGFR (i.e. lapatinib), are approved and provide some clinical benefit but are often associated with increased toxicity. Tucatinib (ARRY-380) is an orally available, potent, highly selective small molecule inhibitor of the HER2 kinase. In this study, we assessed the in vitroand in vivoactivity of tucatinib, relative to approved HER2-targeting molecules, in a panel of molecularly characterized breast cancer cell lines.

Materials and Methods:The growth inhibitory activity of tucatinib, trastuzumab and lapatinib were evaluated in a panel of 48 breast cancer cell lines molecularly characterized at baselineby genomic (array-CGH) and proteomic (Reverse Phase Protein Array; RPPA) profiling. IC50values for tucatinib and lapatinibwere determined from direct cell counts using a Cellavista Cell Imaging System. Trastuzumab activity was measured as % inhibition of cell growth at fixed concentrations. In vivoefficacy of tucatinib was assessed in cell line xenograft models of HER2+/ER- and HER2+/ER+ breast cancers as a single agent or in combination with targeted therapies for breast cancer.

Results: A broad range of IC50values (3.2nM to &gt;10μM), was seen for tucatinib with a high degree of selectivity for the HER2-amplfied sub-type. High levels of total and phosphorylated HER2 (pHER2) accompanied by high levels of pEGFR and pHER3 enriched for sensitivity to tucatinib, confirming that HER2-driven cancers may be uniquely sensitive to tucatinib. The response profile for lapatinib was less clean, with responses also observed in HER2-low/EGFR-high cell lines. Sensitivity to tucatinib was also observed in HER2-amplified cell lines that were either de novoor acquired resistant to trastuzumab. Single agent tucatinib induced tumor regressions in a xenograft model of HER2+/ER+ breast cancer. Tumor regressions were further enhanced by combination with trastuzumab. The combination of tucatinib plus trastuzumab was as efficacious and better tolerated than trastuzumab plus docetaxel or trastuzumab plus pertuzumab plus docetaxel. The triple combination of tucatinib plus hormonal blockade (fulvestrant) and CDK4/6 inhibition (abemaciclib) also induced robust tumor regressions, without significant body weight loss.

Discussion: These preclinical data highlight the potential of the HER2-selective small molecule inhibitor, tucatinib, to provide benefit to patients with HER2-amplifed cancers. Furthermore, our biomarker analysis of response to tucatinib has identified a HER2-driven signature within the HER2-amplfied sub-type that selects for sensitivity to tucatinib. Selecting patients based on this profile may further enrich for individuals most likely to benefit from tucatinib-based therapies.

Citation Format: O'Brien NA, Conklin D, McDermott M, Luo T, Ayala R, Issakhanian S, Salgar S, Hurvitz S, Slamon DJ. The small molecule inhibitor of HER2, tucatinib, has potent and highly selective activity in preclinical modes of HER2-driven cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-11.

Abstract P4-06-07: Activity of nivolumab alone or in combination with targeted therapies in a humanized BLT-mouse model of human breast cancer

Background: Recent advances in the field of cancer immunotherapy have increased demand for reliable preclinical models to inform patient selection and rational drug combination strategies. The development of the bone marrow-liver-thymus (BLT) mouse may provide the opportunity to study the complex interactions of human tumor and host immune systems in vivo. Other models are limited by the rapid onset of graft versus host disease (GVHD) and a lack of orderly maturation and trafficking of human T and B cells. In BLT mice, implantation of human fetal liver and thymus fragments beneath the kidney capsule of NSG (NOD/SCID/IL-2RΥ-/-) mice followed by engraftment of matched ex vivoexpanded CD34+ cells supports the production of an almost complete human immune system. In this study, we used this model to assess the efficacy of the anti-PD-1 therapeutic antibody, nivolumab, in combination with targeted therapeutics in specific breast cancer sub-types.

Materials and Methods: For triple negative breast cancer (TNBC), the activity of nivolumab was assessed in combination with the PARP1/2 inhibitor, talazoparib, in humanized BLT mice. Xenografts were established by subcutaneous injection of 5.0x106MDA-231 (TNBC) cells. Mice (n=5) were randomized into treatment groups as follows; 1) Vehicle control (PBS), 2) nivolumab (10mg/kg QW), 3) talazoparib (0.33mg/kg Q5/2D) and 4) nivolumab+talazoparib. After 21 days of treatment, tumor tissue, serum and PBMCs were collected for biomarker analysis.

Results: Successful reconstitution of mature human T and B cells was confirmed in BLT mice 12-weeks post engraftment of donor tissue and CD34+ hematopoietic stem cells. MDA-231 cells injected subcutaneously into the flank of these mice formed palpable tumors (150-200mm3) within 9 days of injection. For vehicle control treated mice, tumors grew (2.5-fold) throughout the 21-day study. Single agent nivolumab induced significant tumor growth inhibition (TGI) relative to vehicle control treated mice at Day 21. Single agent talazoparib also induced comparable levels of TGI as did the combination of nivolumab plus talazoparib. Nivolumab treated mice continued to gain weight throughout the study without overt signs of toxicity. Reversible weight loss was observed in the talazoparib and combination treated arms. Overt signs of GVHD were not observed in any of these animals. Preliminary tissue analysis identified high levels of cell surface PD-L1 protein in control treated MDA-231 xenografts. Further analysis of the treated tumors will provide valuable insight into the mechanism of action of this class of molecule. We are establishing xenograft models of hormone receptor (ER+) positive breast cancer to measure the activity of nivolumab+/-CDK4/6-inhibition in humanized BLT mice and these data will also be presented.

Discussion: The data presented here highlight the potential of the PD-1 antibody nivolumab to have activity in TNBC. Furthermore, these findings illustrate the potential of the humanized BLT-mouse to model responses to immune check-point in the preclinical setting. Expanded use of this model may help to identify response biomarkers and inform design of combination therapies using immune oncology molecules and approved targeted therapies.

Citation Format: O'Brien NA, Luo T, Ayala R, Salgar S, Conklin D, McDermott M, Kitchen S, Rezek V, Horak C, Dugan U, Slamon DJ. Activity of nivolumab alone or in combination with targeted therapies in a humanized BLT-mouse model of human breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-06-07.

Abstract P5-03-02: Pre-clinical investigation of PP2A inhibitor LB-100 in overcoming and preventing lapatinib resistance in HER2-positive breast cancer

Background: HER2-positive breast cancer (BC) accounts for approximately 15% of all BC. HER2-targeted therapies, such as trastuzumab and lapatinib, have significantly improved the outcome for these patients. However, HER2-targeted therapy resistance is a common clinical issue. We have previously shown that protein phosphatase 2A (PP2A) plays a role in mediating acquired lapatinib resistance in HER2-positive BC and that response to lapatinib is enhancedin vitroby the lab-grade PP2A inhibitor, okadaic acid. The aim of this study was to examine the in vitro and in vivo efficacy of LB-100, a PP2A inhibitor that has completed phase I clinical testing (NCT01837667), in models of HER2-positive BC with acquired resistance to lapatinib.

Methods: HER2-positiveSKBR3 and HCC1954 BC cell lines were treated with 250 nM or 1 μM lapatinib, respectively, for 6 months to generate lapatinib-resistant SKBR3-L and HCC1954-L cell lines. In vitro sensitivity to lapatinib and LB-100 was assessed by 2D acid phosphatase assay. Combination index (CI) values were generated to identify synergistic combinations. Propidium iodide staining was used to determine cell cycle arrest and apoptosis. In order to examine the in vivo efficacy of LB-100, HCC1954-L cells were implanted into the mammary fat pad of BALB/c nude mice and treated with vehicle, lapatinib, LB-100, or lapatinib plus LB-100. To examine the prevention of the development of lapatinib resistance, SKBR3 and HCC1954 cells were treated twice weekly with lapatinib, LB-100 or the combination and stained with crystal violet when confluent.

Results: SKBR3-L and HCC1954-L cells were resistant to lapatinib at clinically relevant concentrations (IC50values = 2.37 ± 0.58 μM and 1.67 ± 0.34 μM). This represents a 46- and 5.2-fold decrease in lapatinib sensitivity. LB-100 had a greater anti-proliferative effect in the lapatinib-resistant SKBR3-L and HCC1954-L cell lines compared to their respective parental cell lines (IC50values = 2.12 ± 0.2 μM v 5.38 ± 0.6 μM, and 2.31 ± 0.19 μM v 5.32 ± 0.82 μM, respectively). LB-100 overcame lapatinib resistance in both models, as lapatinib plus LB-100 was synergistic in both cell lines (CI values = 0.56 ± 0.13 and 0.68 ±0.26). LB-100 caused cell death through the induction of apoptosis in SKBR3- L (p = 0.019) and HCC1954-L (p = 0.046) and the addition of lapatinib to LB-100 increased apoptotic induction in HCC1954-L cells (p=0.046).Lapatinib plus LB-100 was well tolerated in vivo. The HCC1954-L cell line maintained resistance to lapatinib in vivo and the combination of lapatinib and LB-100 significantly reduced HCC1954-L tumour volume compared to all other treatment arms (p = 0.0006). Interestingly, in vitro short-term resistance assays showed that the addition of LB-100 to lapatinib could also block the emergence of lapatinib resistance in both parental SKBR3 and HCC1954 cell lines.

Conclusions: This study indicates that LB-100 has in vitro and in vivo efficacy against lapatinib-resistant HER2-positive BC cell line models and justifies further investigation into its potential to circumvent or prevent lapatinib resistance in HER2-positive BC.

Citation Format: Conlon N, McDermott M, Browne B, Roche S, O'Neill F, Meiller J, Browne A, Eustace A, Collins DM, O'Donovan N, Crown J. Pre-clinical investigation of PP2A inhibitor LB-100 in overcoming and preventing lapatinib resistance in HER2-positive breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-03-02.

Acoustic Supercoupling in a Zero-Compressibility Waveguide

Funneling acoustic waves through largely mismatched channels is of fundamental importance to tailor and transmit sound for a variety of applications. In electromagnetics, zero-permittivity metamaterials have been used to enhance the coupling of energy in and out of ultranarrow channels, based on a phenomenon known as supercoupling. These metamaterial channels can support total transmission and complete phase uniformity, independent of the channel length, despite being geometrically mismatched with their input and output ports. In the field of acoustics, this phenomenon is challenging to achieve, since it requires zero-density metamaterials, typically realized with waveguides periodically loaded with membranes or resonators. Compared to electromagnetics, the additional challenge is due to the fact that conventional acoustic waveguides do not support a cut-off for the dominant mode of propagation, and therefore zero-index can be achieved only based on a collective resonance of the loading elements. Here we propose and experimentally realize acoustic supercoupling in a dual regime, using a compressibility-near-zero acoustic channel. Rather than engineering the channel with subwavelength inclusions, we operate at the cut-off of a higher-order acoustic mode, demonstrating the realization and efficient excitation of a zero-compressibility waveguide with effective soft boundaries. We experimentally verify strong transmission through a largely mismatched channel and uniform phase distribution, independent of the channel length. Our results open interesting pathways towards the realization of extreme acoustic parameters and their implementation in relevant applications, such as ultrasound imaging, acoustic transduction and sensing, nondestructive evaluation, and sound communications.

Pulmonary aspiration in preschool children with cystic fibrosis

Pulmonary aspiration of gastric refluxate (PAGR) has been demonstrated in association with pulmonary inflammation in school aged children with Cystic Fibrosis (CF). We sought to determine if similar findings were present in preschool children. Pepsin was measured in Broncho-alveolar lavage (BAL) fluid collected from clinically stable preschool children with CF and controls. Elevated pepsin levels were found in a subgroup of children with CF, but this was not found to be associated with pulmonary infection, pulmonary inflammation or respiratory or gastrointestinal symptoms.

Abstract P3-02-05: Does MRI influence surgical planning more than clinical outcome? A cohort study of breast cancer patients receiving neoadjuvant therapy

Background: While magnetic resonance imaging (MRI) is a powerful diagnostic tool, there is currently no consensus on its role for breast cancer patients prior to the initiation of neoadjuvant therapy (NAT). In the adjuvant setting, there is evidence that the use of MRI is correlated with an increase the rate of mastectomies performed. There is currently no data describing how MRI is influencing treatment decisions or surgical management in the neoadjuvant setting. This study aimed to determine the impact of MRI on patients' surgical plan, and to understand the demographic differences in patients who had an MRI compared to those that did not in the neoadjuvant setting.

Methods: A secure database containing all potential NAT patients seen by medical oncologists at the BC Cancer Agency Vancouver Centre since 2012 was searched. Breast cancer patients who were treated with NAT and had undergone breast surgery before March 30, 2016 were identified. Tumour characteristics, surgical plan and surgical outcome were assessed retrospectively and compared between patients who had an MRI and patients who did not have an MRI.

Results: 270 patients were identified who met the inclusion criteria. Of those, 107 patients had a breast MRI and 163 patients did not. The two groups showed no significant pre-treatment differences with regards to type of breast cancer, receptor status, or clinical stage. The median age was 10 years younger in the MRI group (47 years) compared to the non-MRI group (57 years), p &lt; 0.0001. Patients who had an MRI had a non-significant higher rate of pathological complete response (pCR) than those who did not (30.8% and 21.5%, respectively, p=0.08). The surgical treatment did differ between these two groups; those who had MRI were more likely to have bilateral mastectomy (36.4% vs 23.3%, p=0.019) and less likely to have breast conserving surgery (BCS) (19.6% vs 31.9%, p=0.026). In the cohort that had an MRI, there was no significant difference in percentage of patients whose surgical plan was changed compared to the patients who did not have an MRI (33.6% and 28.8%, respectively). A change in surgical plan from a mastectomy to a BCS was more common in patients who did not have an MRI than those that did (31.9% and 13.9%, respectively). 45% of the surgeons who dictated a follow-up surgery consultation stated that the MRI was used to inform the surgical plan.

Discussions/Conclusions: In this real-world cohort, patients who had an MRI were more likely to undergo a bilateral mastectomy and less likely to have a BCS than the patients who did not have an MRI, despite having a higher rate of pCR. Age was the only baseline demographic difference between the two groups. These findings suggest that the role of MRI in the neoadjuvant setting needs to be refined further in order to avoid over-treatment.Background: While magnetic resonance imaging (MRI) is a powerful diagnostic tool, there is currently no consensus on its role for breast cancer patients prior to the initiation of neoadjuvant therapy (NAT). In the adjuvant setting, there is evidence that the use of MRI is correlated with an increase the rate of mastectomies performed. There is currently no data describing how MRI is influencing treatment decisions or surgical management in the neoadjuvant setting. This study aimed to determine the impact of MRI on patients' surgical plan, and to understand the demographic differences in patients who had an MRI compared to those that did not in the neoadjuvant setting.

Methods: A secure database containing all potential NAT patients seen by medical oncologists at the BC Cancer Agency Vancouver Centre since 2012 was searched. Breast cancer patients who were treated with NAT and had undergone breast surgery before March 30, 2016 were identified. Tumour characteristics, surgical plan and surgical outcome were assessed retrospectively and compared between patients who had an MRI and patients who did not have an MRI.

Results: 270 patients were identified who met the inclusion criteria. Of those, 107 patients had a breast MRI and 163 patients did not. The two groups showed no significant pre-treatment differences with regards to type of breast cancer, receptor status, or clinical stage. The median age was 10 years younger in the MRI group (47 years) compared to the non-MRI group (57 years), p &lt; 0.0001. Patients who had an MRI had a non-significant higher rate of pathological complete response (pCR) than those who did not (30.8% and 21.5%, respectively, p=0.08). The surgical treatment did differ between these two groups; those who had MRI were more likely to have bilateral mastectomy (36.4% vs 23.3%, p=0.019) and less likely to have breast conserving surgery (BCS) (19.6% vs 31.9%, p=0.026). In the cohort that had an MRI, there was no significant difference in percentage of patients whose surgical plan was changed compared to the patients who did not have an MRI (33.6% and 28.8%, respectively). A change in surgical plan from a mastectomy to a BCS was more common in patients who did not have an MRI than those that did (31.9% and 13.9%, respectively). 45% of the surgeons who dictated a follow-up surgery consultation stated that the MRI was used to inform the surgical plan.

Discussions/Conclusions: In this real-world cohort, patients who had an MRI were more likely to undergo a bilateral mastectomy and less likely to have a BCS than the patients who did not have an MRI, despite having a higher rate of pCR. Age was the only baseline demographic difference between the two groups. These findings suggest that the role of MRI in the neoadjuvant setting needs to be refined further in order to avoid over-treatment.

Citation Format: McDermott M, Wilson C, Xu J, Illmann C, Simmons C. Does MRI influence surgical planning more than clinical outcome? A cohort study of breast cancer patients receiving neoadjuvant therapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-02-05.

Abstract P3-02-09: Do radiographic features influence the decision to order a breast MRI? A prospective cohort study

Background:

The clinical impact of breast MRI in the neoadjuvant setting is unclear. It is assumed that MRI may help with surgical planning. Factors that may affect whether an MRI is ordered for breast cancer in the neoadjuvant setting may include both imaging and tumour characteristics. Literature suggests MRI can be used in the neoadjuvant therapy (NAT) if there is evidence of high density of breast tissue, multifocal disease, multi-centric disease, lymph node involvement or presence of calcifications. In a non-trial setting, it is unclear when MRI is ordered and if it is indeed ordered based on the above imaging criteria. We sought to determine how MRI is currently implemented in a provincial practice to determine which patients are selected for MRI prior to NAT. Specifically, we aimed to determine if the imaging characteristics determined likelihood of use of MRI in the neoadjuvant setting.

Methods:

Patients who received neoadjuvant therapy between May 2012 and May 2016 were captured in a prospective database at the BC Cancer Agency in Vancouver. Patients were reviewed and identified as those who either received a breast MRI or not. A random sample of 80 cases, 40 who received MRI and 40 who did not, was taken from this database. Charts were reviewed in detail, and detailed review of the radiographic features from mammogram and ultrasound imaging reports was recorded.

Results:

80 patients were reviewed in detail. There were no differences in patient demographics or tumour characteristics. Imaging review demonstrated no statistical significant difference in use of MRI based on reported density, multi-centric disease, calcifications, and nodal involvement. The only radiographic feature that was different was presence of multifocal disease on conventional imaging, where 40.0% of patients who had an MRI had multifocal disease reported whereas only 17.5% of those who did not have an MRI had multifocality reported (p = 0.03).

Discussion/Conclusions:

Despite radiographic guidelines for use of MRI, the decision by the ordering physician regarding who should receive an MRI prior to NAT still appears to be unsystematic. This could be due to incorrect interpretation of radiographic reports by the ordering physicians and lack of availability or access to the interpreting radiologist. Results suggest that the ordering physician is already aware of multifocal disease and is utilizing MRI to verify this presence, rather than using MRI to investigate the possibility of multifocality in dense breast tissue. Based on this strategy of use it is unlikely that MRI will reduce the rate of mastectomy in this patient population.

Table 1: Summary of radiographic features in MRI vs. non-MRI cohorts MRI (N=40)No MRI (N=40)Chi SquareDensity (C or D)25 (62.5%)16 (40.0%)p=0.11Multifocal Disease16 (40.0%)7 (17.5%)p=0.03Multi-centric Disease7 (17.5%)3 (7.5%)p=0.19Lymph Node Involvement31 (77.5%)25 (62.5%)p=0.25Calcifications Present23 (57.5%)21 (52.5%)p=0.56

Citation Format: Illmann C, Simmons CE, McDermott M, Xu J, Wilson C. Do radiographic features influence the decision to order a breast MRI? A prospective cohort study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-02-09.

Critical care in acute ischemic stroke

Most ischemic strokes are managed on the ward or on designated stroke units. A significant proportion of patients with ischemic stroke require more specialized care. Several studies have shown improved outcomes for patients with acute ischemic stroke when neurocritical care services are available. Features of acute ischemic stroke patients requiring intensive care unit-level care include airway or respiratory compromise; large cerebral or cerebellar hemisphere infarction with swelling; infarction with symptomatic hemorrhagic transformation; infarction complicated by seizures; and a large proportion of patients require close management of blood pressure after thrombolytics. In this chapter, we discuss aspects of acute ischemic stroke care that are of particular relevance to a neurointensivist, covering neuropathology, neurodiagnostics and imaging, blood pressure management, glycemic control, temperature management, and the selection and timing of antithrombotics. We also focus on the care of patients who have received intravenous thrombolysis or mechanical thrombectomy. Complex clinical decision making in decompressive hemicraniectomy for hemispheric infarction and urgent management of basilar artery thrombosis are specifically addressed.

A Retrospective Cohort Study of Total Colonic Aganglionosis: Is the Appendix a Reliable Diagnostic Tool?

Background: Hirschsprung's disease (HD) is characterized by a lack of ganglion cells in the myenteric and submucosal plexus, associated with increased numbers of acetyl cholinesterase (AChE) positive nerve fibres. In approximately 10% of patients with HD the entire colon will be affected; a condition known as Total Colonic Aganglionosis (TCA). Aganglionosis of the appendix has long been considered to be an important finding in a patient in whom TCA is suspected, but its reliability for diagnosis has seldom been discussed. The aim of our study was to assess the reliability of the appendix as a histological specimen for the diagnosis of TCA, and to evaluate the long-term outcome of TCA.

Methods: A retrospective cohort study was performed of all pathological specimens of patients with confirmed HD in our institution between March 2006 and April 2016.

Results: Out of a total of 91 patients identified, 15 patients also had histopathological analysis of the appendix. Nine of these cases were confirmed as having TCA. The remaining 6 patients had HD involving the rest of the bowel up to the ascending colon, with normal ganglion present in the caecum. The appendix was removed in all the 15 cases. All 9 patients with confirmed TCA had aganglionosis of the appendix as well. The remaining 6 cases of short and long segment HD not involving the caecum, demonstrated normal ganglion cells within the appendix.

Conclusion: Aganglionosis of the appendix is a reliable tool in the diagnosis of TCA. The authors recommend that at the time of levelling biopsies, if aganglionosis extends to the mid-transverse colon, an ileostomy be performed and appendix sent for definitive confirmation of TCA. However, at the time of definitive surgery, a frozen section of pull-through segment of bowel is recommended to confirm the presence of ganglion cells.

Odontogenic myxoma of the maxilla: surgical management and case report

BACKGROUND

Odontogenic myxoma is a benign odontogenic tumour of the jaw [1]. This tumour often presents as an asymptomatic expansile lesion without sensory nerve changes [2]. It is thought to arise from mesenchymal origin with cells of microscopic similarity to dental pulp and follicle [3]. Radiographically it presents most often as a multiloculated radiolucency [2]. It is a locally aggressive lesion which may require extensive treatment to prevent recurrence.

METHOD

The authors present the case of a 13-year-old boy with an extensive lesion in the maxilla.

CONCLUSION

We discuss various treatment approaches for management of this tumour.

Post-transplant lymphoproliferative disorder in paediatric patients: the Irish perspective-a single centre experience

BACKGROUND

Post-transplant lymphoproliferative disease (PTLD) is a serious complication of both solid organ and haematopoietic stem cell transplantation in children. Its incidence has increased over the last decade as a result of more potent immunosuppressive regimens. Many treatments have been explored however optimal therapy remains controversial.

AIMS

We report on the diagnosis, treatment and outcome of ten patients who were diagnosed with PTLD in Our Lady's Hospital for Sick Children in Dublin between 2004 and 2015 inclusive.

METHODS

Data were collected by retrospective review of patient medical records.

RESULTS

9 out of ten of our patients are alive and disease free following treatment for PTLD with rituximab alone or in combination with chemotherapy.

CONCLUSION

The outcome of paediatric patients treated for PTLD at our institution is at least comparable to published international series and supports the use of rituximab ± low dose chemotherapy in the treatment of this malignancy.