Treatment Efficacy Outcomes Combining Dual Checkpoint Immunotherapy with Ablative Radiation to All Sites of Oligometastatic Non-Small Cell Lung Cancer: Survival Analysis of a Phase IB trial

PURPOSE/OBJECTIVE(S)

Aggressivelocal treatment to a limited number of metastatic sites in patients with oligometastatic NSCLC increases progression free survival (PFS) and overall survival (OS). Prior studies have shown the safety of combining high dose stereotactic body radiation therapy (SBRT) with single agent anti-PD1/PD-L1 therapy. Here, we report secondary survival endpoint outcomes from a phase Ib clinical trial investigating the safety of combining ablative, high dose radiation with dual checkpoint, anti-CTLA-4 and anti-PD-L1 immunotherapy for patients with oligometastatic NSCLC.

MATERIALS/METHODS

Patients with up to 6 sites of extracranial metastatic disease were eligible for trial enrollment. All sites of disease were treated with stereotactic body radiation therapy to a dose of 30 - 50 Gy in 5 fractions. Dual checkpoint immunotherapy was started 7 days following completion of radiation utilizing anti-CTLA-4 (Tremelimumab) and anti-PD-L1 (Durvalumab) immunotherapy for a total of four cycles followed by durvalumab alone until dose limiting toxicity or progression was observed. Primary toxicity outcomes were previously reported. Progression free and overall survival was analyzed using Kaplan Meier statistical methods.

RESULTS

Fifteen patients were treated with SBRT and received at least one dose of dual agent immunotherapy per protocol. The median follow up was 43 months. The median number of extracranial metastatic sites was 2. Seven patients had 3 or more sites of extracranial disease. The most commonly treated sites were separate metastatic pulmonary lesions or osseous metastatic lesions. Median progression free survival (PFS) was 42 months and median overall survival (OS) was 48 months. Seven patients remain alive without evidence of progressive disease. Prior history of brain metastases was associated with significantly worse PFS (Median PFS 4 months vs 42 months, HR 6.1 (95% CI 1.6 - 37.0) p = 0.0248), but no difference in OS (Median OS 24 vs 42 months, HR 1.9 (95% CI 0.3 - 10.4).

CONCLUSION

Ablative SBRT radiation to up to 6 sites of disease followed by dual checkpoint immunotherapy in oligometastatic NSCLC resulted in a favorable progression free survival (42 months) and overall survival (48 months) compared to historical controls. These findings suggest potential benefit to patient outcomes compared to immunotherapy or radiation alone in this patient population and warrant further investigation.

Disease and Toxicity Outcomes after Salvage Radiotherapy (SRT) for Biochemically Recurrent Prostate Cancer (PC) for Patients Enrolled in a Phase II, Open Label Trial Investigating Neoadjuvant Chemohormonal Therapy Followed by Radical Prostatectomy (RP)

PURPOSE/OBJECTIVE(S)

Men with metastatic hormone sensitive prostate cancer have improved progression free and overall survival (PFS/OS) when treated with docetaxel and androgen deprivation therapy (ADT). Our institution conducted a phase II trial (UW17009) investigating the addition of three cycles of neoadjuvant docetaxel and ADT to RP in men with high-risk prostate cancer. Here we report toxicity and freedom from biochemical recurrence (FFBCR) for patients treated with SRT following participation in this trial.

MATERIALS/METHODS

Between January 17, 2018 and August 10, 2021, 28 patients enrolled on UW17009. Patients who had a recurrence and received SRT were identified. Toxicity was assessed using modified LENT (Late Effects of Normal Tissues)/RTOG (Radiation Therapy Oncology Group) criteria, and time to recurrence following SRT was determined for each patient. Additionally, the months of ADT received by each patient was recorded. FFBCR was then determined for this cohort using the method of Kaplan and Meier.

RESULTS

Of 28 patients enrolled on UW17009, 20 (71%) had BCR after RP. Of these, 19 received SRT, representing 68% of the patients enrolled on the trial. The rates of acute grade 1 and grade 2 GU toxicity with SRT were 37% (7) and 53% (10), respectively. The rates of acute grade 1 and grade 2 GI toxicity with SRT were 32% (6) and 37% (7), respectively. On patient experienced a grade 4 genitourinary toxicity during SRT. There were no acute grade 3 or grade 5 toxicities. The rates of late grade 1 and grade 2 GU toxicity were 16% (3) and 11% (2), respectively. The rates of late grade 1 and grade 2 GI toxicity were 11% (2) and 5% (1), respectively. There was 1 (5%) late grade 3 GU toxicity. There were no late grade 3-5 GI toxicities, or late grade 4-5 GU toxicities. The average duration of ADT after prostatectomy was 15 months (range: 0-37 months). According to the method of Kaplan and Meier, mean FFBCR after SRT was 34.0 months at a median of 37.8 months. Median FFBCR had not yet been reached. At the time of analysis, 13 patients remained free from biochemical recurrence after SRT.

CONCLUSION

Rates of biochemical recurrence and SRT following neoadjuvant docetaxel and ADT and then RP were consistent with historical data, as was the rate of successful SRT. Toxicities were also consistent with historical data, though there was notably one acute grade 4 GU toxicity.

Low-Dose Fractionated Radiotherapy Combined with Neoadjuvant Chemotherapy for T3-4 Nasopharyngeal Carcinoma Patients: The Preliminary Results of a Phase II Randomized Controlled Trial

PURPOSE/OBJECTIVE(S)

Over 70% of NPC patients were local advanced NPC (LANPC). The 5-year local recurrence-free survival rate is only 70% in T3-4 patients. Neoadjuvant chemotherapy (NACT) followed with concurrent chemoradiotherapy (CCRT) was recommended for LANPC patients. Low-dose fractionated radiotherapy (LDFRT), which is <100cGy, induces enhanced cell killing by the hyper-radiation sensitivity phenomenon and potentiates effects of chemotherapy. The synergy of LDFRT and NACT has not been used in the clinical practice and few studies focused on it. A single arm study found the ORR of primary site was improved to 90% for head and neck squamous carcinoma patients treated with LDFRT and NACT. Our previous study found the ORR of lymph nodes was higher in LDFRT group for high-risk LANPC patients. However, another study showed there was no significant difference between LDFRT and control group for LANPC patients. So, we aimed to investigate the potential efficacy of this novel neoadjuvant therapy for T3-4 NPC patients.

MATERIALS/METHODS

A total of 60 pathological confirmed T3-4 (UICC/AJCC8th) NPC patients were prospectively enrolled in our study. They were randomly assigned to two groups. For the LDFRT group, the patients received 3 cycles of NACT (docetaxel 75mg/m2 D1, cisplatin 80mg/m2 D1) with LDFRT, and followed with CCRT. LDFRT was delivered as 50cGy per fraction twice a day to primary site on D1,2 for each cycle of NACT. The patients in the control group only received NACT and followed with CCRT. All the patients underwent IGRT. RECIST criteria and CTCAE 5.0 was used to evaluate the ORR and toxicity at post-NACT and the completion of CCRT.

RESULTS

From February 2022 to December 2022, 60 T3-4 NPC patients were included, and 30 patients for each group. For the primary site, the median volume reduction rate and the ORR after NACT was significantly improved in LDFRT group (69.27% vs 40.10%, p<0.001;93.33% vs 73.33%, p = 0.038). For the median volume reduction rate of primary site and lymph node, it was also obviously improved in LDFRT group (86.59% vs 55.43%, p<0.001). Though there was a tendency of ORR improvement in LDFRT group, but no significant difference (96.67% vs 83.33%, p = 0.195). After the completion of CCRT, the median volume reduction rate of primary site had an increased tendency in LDFRT group (96.16% vs 88.3%, p = 0.065), but the ORR had no statistical significance (LDFRT group: CR 45.8%, PR 54.2%; control group: CR 37.5%, PR 62.5%). For the toxicity, the incidence of grade 3-4 adverse events had no difference between two groups (p = 0.786). No grade 5 adverse events occurred.

CONCLUSION

LDFRT combined with NACT could obviously improve the median volume reduction rate and ORR of primary tumor for T3-4 NPC patients, and the toxicity was similar and tolerable. This novel treatment could be a promising strategy to improve treatment response and needed to be confirmed further.

Long-Term Survival Outcome for Metastatic Nasopharyngeal Carcinoma Patients Receiving Radiation to Primary and Metastatic Sites with Palliative Chemotherapy

PURPOSE/OBJECTIVE(S)

A total of 6% - 8% of NPC patients were initial diagnosed as distant metastatic disease. The median overall survival (OS) is only 10-15 months with palliative chemotherapy for these patients. A phase III study showed that palliative chemotherapy combined with radical radiotherapy to primary site could be a newly effective treatment method for metastatic NPC. Another phase 2, RCT found that the patients who had the solid tumors with 1-5 metastases received standard palliative care plus stereotactic body radiation therapy (SABR), and the 5-year OS were improved to 42.3%. Nevertheless, there was few studies focus on the radiation to both primary site and metastatic lesions. Therefore, we aimed to investigate the potential clinical benefits for initial diagnosed metastatic NPC patients with radiation to both primary site and distant metastatic lesions plus palliative chemotherapy.

MATERIALS/METHODS

Metastatic NPC patients treated with radiation to both primary site and distant metastatic lesions plus palliative chemotherapy were retrospectively collected in our hospital from May 2008 to May 2022. For treatment group, all patients underwent IGRT according to ICRU reports 50 and 62. The prescribed dose for primary site: GTVT: ≥66Gy, GTVn: ≥66Gy, CTV1: 60-66Gy, CTV2 54-60Gy, CTVln 50-54Gy. And the prescribed dose for distant metastatic lesions was more than 30Gy. For the control group, the patients treated with palliative chemotherapy were selected by propensity score matching from our hospital. The regimen for palliative chemotherapy was cisplatin-based chemotherapy every three weeks (100mg/m2 D1) for both groups. Kaplan-Meier method was used to analyze the OS. Cox regression model was used for multivariate analysis.

RESULTS

A total of 54 metastatic NPC patients with radiation to both primary site and distant metastatic lesions were retrospectively included in the treatment group, and another 54 patients were selected as the control group. The median follow-up time was 52 months. In the treatment group, the median age was 52 years (37-82), male (68%), female (32%), the main metastatic sites were bone (36 cases, 66%), lung (18 cases, 33%) and liver (10 cases, 18%). There were 23 oligometastasis cases and 31 cases. 3-year and 5-year OS in the treatment group were both dramatically improved than control group (63.2% vs 50.6%, p<0.05; 49.6% vs 38.9%, p<0.05). Multivariate analysis showed that T stage, liver metastatic lesion and oligometastases were the independent prognostic factors for them.

CONCLUSION

Palliative chemotherapy combined with radiation to primary sites and distant metastatic lesions might improve the OS for initial diagnosed distant metastatic NPC patients. More prospective clinical trials were needed to confirm it further.

A Ferroptosis Microneedle Integrated Wireless Implanted Photodynamic Therapy Pellet for Cancer Treatment

PURPOSE/OBJECTIVE(S)

Effective, non-toxic, and targeted induction of lung cancer cell death is urgently needed. The goal of this research is to create a new implantable battery-free therapeutic pellet with integrated drug microneedles that allows for wireless photodynamic therapy (PDT) and targeted release of a ferroptosis inducer (Imidazole ketone erastin, IKE) into tumor tissue.

MATERIALS/METHODS

A wireless power unit, μ-LED illuminant, a flexible control circuit, and an IKE-stored biodegradable microneedle enclosed in polydimethylsiloxane (PDMS) were all built into an integrated therapeutic pellet. Lung cancer cells were used to illustrate the in vitro viability and molecular biological processes of this system. Therapeutic pellet implanted into the LLC xenograft C57BL/6 model. PDT was conducted by 660 nm laser irradiation after injecting a photosensitizer (Chlorin e6, Ce6) and targeted IKE released into the tumor. Systematically analyzing the therapeutic effects on lung cancer and toxic side-effects.

RESULTS

The PDT-IKE group reduced cellular viability by 90% compared to the control group at the cellular level. In mouse model studies, the PDT-IKE group suppressed tumors at 78.8%, three or four times greater than the PDT (26.6%) or IKE (19.2%) group alone. The PDT-IKE group also controlled IKE release more precisely with heated electrodes, reducing nephrotoxicity and improving safety. Moreover, the combination of PDT and IKE can effectively cause ferroptosis in tumor cells, both in vivo and in vitro.

CONCLUSION

A new implantable battery-free therapeutic pellet was designed for wireless PDT with integrated IKE microneedles to induce obvious ferroptosis in lung cancer. The proposed pellet would provide a promising strategy for cancer treatment.

Collision-induced three-body polarizability of helium

We present the first-principles determination of the three-body polarizability and the third dielectric virial coefficient of helium. Coupled-cluster and full configuration interaction methods were used to perform electronic structure calculations. The mean absolute relative uncertainty of the trace of the polarizability tensor, resulting from the incompleteness of the orbital basis set, was found to be 4.7%. Additional uncertainty due to the approximate treatment of triple and the neglect of higher excitations was estimated at 5.7%. An analytic function was developed to describe the short-range behavior of the polarizability and its asymptotics in all fragmentation channels. We calculated the third dielectric virial coefficient and its uncertainty using the classical and semiclassical Feynman-Hibbs approaches. The results of our calculations were compared with experimental data and with recent Path-Integral Monte Carlo (PIMC) calculations [Garberoglio et al., J. Chem. Phys. 155, 234103 (2021)] employing the so-called superposition approximation of the three-body polarizability. For temperatures above 200 K, we observed a significant discrepancy between the classical results obtained using superposition approximation and the ab initio computed polarizability. For temperatures from 10 K up to 200 K, the differences between PIMC and semiclassical calculations are several times smaller than the uncertainties of our results. Except at low temperatures, our results agree very well with the available experimental data but have much smaller uncertainties. The data reported in this work eliminate the main accuracy bottleneck in the optical pressure standard [Gaiser et al., Ann. Phys. 534, 2200336 (2022)] and facilitate further progress in the field of quantum metrology.

Knowledge and attitudes towards epilepsy: A survey of people with epilepsy

PROBLEM

Many studies focus on knowledge and attitudes of unaffected people towards epilepsy and people with epilepsy (PWE). The perspective of PWE themselves is much less explored.

METHODS

We invited PWE in Germany to answer a questionnaire on their knowledge and attitudes towards epilepsy and PWE.

RESULTS

The questionnaire was completed by 230 PWE (median age: 40 years; min./max.: 19/83; 66 % female). Of PWE, 22 % thought that PWE are more helpful, and 10 % thought that PWE are friendlier than other people. Nevertheless, reservations about relationships and friendships with other PWE existed: of the participants, only 74 % would definitely go on a date with another PWE, and 90 % would definitely include another PWE they liked into their circle of friends. Swimming was judged as more dangerous for PWE than for healthy people by 71 % of PWE. Of PWE, 86 % correctly assumed it was not useful to hold a person having a seizure to the ground. Putting a solid object in the mouth was considered not useful by 85 % of PWE. Of PWE, 20 % would definitely administer an available emergency medication if another PWE had a seizure. For 67 % of PWE, certain preconditions should have to be fulfilled such as an available document with instructions. Of PWE, 11 % stated they would not administer an available emergency medication if another PWE had a seizure.

CONCLUSION

Although positive attitudes of PWE towards other PWE exist, we also found some reservations calling for psychosocial support. Most PWE had sufficient knowledge about risks of certain activities and about measures to be taken during a seizure. Nevertheless, a small group of PWE showed knowledge gaps. Thus, educational support still seems essential.

POS1485-HPR DIGITALLY ENHANCED TREAT-TO-TARGET AND SHARED DECISION-MAKING APPROACH WITH A DIGITAL HEALTH APPLICATION: INTERIM RESULTS FROM A RANDOMIZED CONTROLLED TRIAL

Background

Digital health applications (DHA) became indispensable patient companions accelerated by the current COVID pandemic [1]. In 2020, for the first time worldwide, a regulatory framework to reimburse DHA was established in Germany. To get listed as a DHA, preliminary evidence needs to be generated – next to fulfilling highest standards in quality and safety. The DHA ABATON RA consists of two parts; 1) digital shared-decision-making (SDM) including choosing an appropriate electronic patient reported outcome (ePRO) instrument and the respective ePRO target for the next visit, 2) remote patient monitoring and ePRO tracking by the patient. Hereby, ABATON RA supports a digitally guided Treat-to-Target (T2T) approach.

Objectives

The objective of this study is to evaluate a potentially beneficial effect for the patient by using ABATON RA.

Methods

Three-armed, partially blinded multicenter trial (RCT) including RA patients who regularly use a smartphone. Patients attend 3 visits, 3 months apart (T0, T3, T6), with one follow-up visit (T9). Intervention group (IG): Patients use ABATON RA. Via SDM patients and rheumatologists choose a specific ePRO and respective treatment target for the next visit in three months, e.g. RAID ≤4. Control group (CG): Standard of care treatment (no DHA). Placebo group (PG): Usage of a placebo version of ABATON RA providing only Regensburger Insomnie Skala (RIS) and Epworth Sleepiness Scale (ESS) as ePROs. No SDM is conducted and ePRO results are not presented to HCP.

Results

This interim analysis evaluated the first 38 patients that completed T3. IG: 13 patients (Av. age 55.9, 61.5% females); PG: 12 (Av. age 50.7, 66.7% females); CG: 13 (Av. age 56.1, 76.9% females). We observe a significant improvement in the mean over time in a pairwise comparison within the intervention group for the following: Pt-GA mean difference of 2.98 (p = 0.025, partial η2 = 0.353), pain mean difference of 1.46 (p = 0.049, partial η2 = 0.286) whereas all pairwise comparisons for the two parameters were non-significant in PG and CG. The patient reactions assessment (PRA) score, measuring patient perceived quality of the patient-provider relationship, increased by a mean of 4.15 points in IG, compared to a slight decrease of 1.92 for PG and 2.77 for CG.

Conclusion

These preliminary findings show beneficial differences among the groups in favor of IG: 1) for quality of life and 2) the physician-patient-relationship. A digitally enhanced therapy is non-inferior to the gold-standard of exclusive in-person treatment. Patients seem willing and able to get involved in an enhanced treat-to-target and shared decision-making approach.

References

[1]Kernder A, Morf H, Klemm P, Vossen D, Haase I, Mucke J, et al. Digital rheumatology in the era of COVID-19: results of a national patient and physician survey. RMD Open. 2021;7:e001548.

Disclosure of Interests

Johannes Knitza Consultant of: ABATON GmbH, Vila Health, Grant/research support from: ABATON GmbH, Manuel Grahammer Shareholder of: ABATON GmbH, Employee of: ABATON GmbH, Sebastian Boeltz: None declared, Judith Lang: None declared, Markus Detert: None declared, Maram Bader Employee of: ABATON GmbH, Arnd Kleyer: None declared, David Simon: None declared, Gerhard Krönke: None declared, Georg Schett: None declared, Jacqueline Detert: None declared

A nationwide population-based survey on the prevalence and risk factors of symptomatic pelvic organ prolapse in adult women in China - a pelvic organ prolapse quantification system-based study

Objective

To determine the prevalence, risk factors and burden of symptomatic pelvic organ prolapse (POP) in adult Chinese women.

Design

A nationwide cross‐sectional study.

Setting

Six geographic regions of mainland China.

Participants

Women aged ≥20 years old were included using a multistage, stratified, cluster sampling method from February 2014 through March 2016.

Methods

We conducted a nationwide epidemiological survey. ‘Symptomatic POP’ was determined by a screening questionnaire and physical examination.

Main outcome measurements

Prevalence, odds ratio (OR).

Results

A total of 55 477 women (response rate, 92.5%; mean age, 45.1 years old) were included. The prevalence of symptomatic POP was 9.6% (95% CI 9.3–9.8%) and it increased with age in each stage (P < 0.05). Symptomatic POP‐Q stage II, which mainly involved anterior compartment prolapse, was the most common (7.52%). Minor/moderate burden of symptomatic POP was the most common, with a prevalence of 9.7% (95% CI 9.5–10.0%). The odds for each type of symptomatic POP increased with age (>50 vs 20‐29 years old in symptomatic POP‐Q stage II or higher, OR increased from 1.34 [95% CI 1.32–1.45] to 7.34 [95% CI 4.34–12.41]) and multiple vaginal deliveries (multiparous [≥3] vs nulliparous in symptomatic POP‐Q stage II or higher, OR increased from 1.91 [1.71–2.13] to 2.78 [2.13–3.64]).

Conclusions

We found a lower prevalence of symptomatic POP than that found in other surveys. The main type of symptomatic POP was anterior compartment prolapse, indicating that it should be considered first. Older age and multiple vaginal deliveries increased the odds of each type of symptomatic POP.

Tweetable abstract

The prevalence of female symptomatic pelvic organ prolapse (POP) was 9.6% in China. It is related to old age and multiple vaginal deliveries.

The prevalence of female symptomatic pelvic organ prolapse (POP) was 9.6% in China. It is related to old age and multiple vaginal deliveries.

Endocrine stress response in pregnancy and 12 weeks postpartum - Exploring risk factors for postpartum depression

Pregnancy and the postpartum period are characterized by physiological alterations in cortisol and cortisone levels. In the present study, we sought to explore the risk factors for postpartum depression (PPD) and self-remitting postpartum adjustment disorder (AD) and whether cortisol/cortisone metabolism might have any bearing on them. Hair samples from 196 participants (mean age = 31.44, SD = 4.71) were collected at two time points (1-6 days after childbirth and 12 weeks postpartum) to determine the cumulative hair cortisol (HCC) and hair cortisone (HCNC) exposure in the third trimester and during the 12 weeks postpartum. Compared to the non-depressed group (ND, n = 141), more women in the AD (n = 28) and PPD (n = 27) groups had a personal or family history of depression and more stressful life events. Compared to ND and PPD, more women in the AD group had birth-related complications with their children being more often transferred to a pediatric ward. The factors associated with PPD were found to include being unmarried and having a lower household income, less support at home, more subjectively perceived stress after childbirth and lower maternal sensitivity. The natural decrease in HCC concentration from the third trimester to 12 weeks postpartum was significant only in the ND and AD groups, but not in PPD. In summary, prolonged subjectively perceived postpartum stress associated with living situations may contribute to the development of PPD while birth- and child-related complications are likely to trigger brief episodes of AD. Only in ND and AD, the pregnancy-related physiological changes in glucocorticoid levels return to the pre-pregnancy baseline after 12 weeks. Our observations point to the difference between the ND and PPD groups in glucocorticoid metabolism-related postpartum adjustment, which may be a factor in the development of PPD.

Generalized headache among Chinese climacteric women: findings from a prospective cohort

OBJECTIVE

This study aimed to prospectively identify the prevalence of generalized headache and associated risk factors in Chinese midlife women.

METHODS

We identified 411 qualified women from a Chinese urban community, contributing a total of 2544 surveys. The presence of generalized headache was measured. Climacteric symptoms and other risk factors were evaluated by generalized estimating equations.

RESULTS

The prevalence of headache complaints is associated with menopausal stages. Perimenopausal women have relatively high prevalence of headache symptoms, especially stage +1a women (59.0%) compared to late postmenopausal women (37.8%), although menopause stages were not statistically significant in the multivariate analysis. Women who had headache at baseline and depression were much more likely to have headache during menopause. According to the univariate and multivariate analyses in women without headache at baseline, starting menopausal status, insomnia, sweats, and depression were independently associated with newly developed headache.

CONCLUSIONS

Symptoms of generalized headache were less prevalent in late postmenopausal women. Our findings highlight the association between headache and climacteric changes.

Improved light extraction efficiency of AlGaN deep-ultraviolet light emitting diodes combining Ag-nanodots/Al reflective electrode with highly transparent p-type layer

Enhancement of light extraction efficiency (LEE) of AlGaN-based deep-ultraviolet (DUV) light emitting diodes (LEDs) has been attempted by adopting Ag-nanodots/Al reflective electrodes on a highly transparent complex p-type layer. By thinning the p-GaN to several nm, highly DUV transparent p-type layer is achieved, making it meaningful for the application of reflective electrodes composed of Ag-nanodots and Al film to allow most light emitted upward to be reflected back to the sapphire side. By this approach, the maximum light output power and external quantum efficiency of the DUV-LEDs with optimized Ag nanodots/Al electrodes are severally increased by 52% and 58%, respectively, compared to those with traditional Ni/Au electrodes when the current is below 200 mA.

Using parametric model order reduction for inverse analysis of large nonlinear cardiac simulations

Predictive high-fidelity finite element simulations of human cardiac mechanics commonly require a large number of structural degrees of freedom. Additionally, these models are often coupled with lumped-parameter models of hemodynamics. High computational demands, however, slow down model calibration and therefore limit the use of cardiac simulations in clinical practice. As cardiac models rely on several patient-specific parameters, just one solution corresponding to one specific parameter set does not at all meet clinical demands. Moreover, while solving the nonlinear problem, 90% of the computation time is spent solving linear systems of equations. We propose to reduce the structural dimension of a monolithically coupled structure-Windkessel system by projection onto a lower-dimensional subspace. We obtain a good approximation of the displacement field as well as of key scalar cardiac outputs even with very few reduced degrees of freedom, while achieving considerable speedups. For subspace generation, we use proper orthogonal decomposition of displacement snapshots. Following a brief comparison of subspace interpolation methods, we demonstrate how projection-based model order reduction can be easily integrated into a gradient-based optimization. We demonstrate the performance of our method in a real-world multivariate inverse analysis scenario. Using the presented projection-based model order reduction approach can significantly speed up model personalization and could be used for many-query tasks in a clinical setting.

Greatly enhanced performance of AlGaN-based deep ultraviolet light emitting diodes by introducing a polarization modulated electron blocking layer

Carrier transport in AlGaN-based deep ultraviolet (DUV) light emitting diodes (LEDs) with the wavelength of 273 nm has been investigated by introducing polarization modulated electron blocking layer (EBL) that adopts an Al composition and thickness graded multiple quantum barriers (MQB) structure. The experimental result shows that the maximum light output power and external quantum efficiency for the proposed structure at the current of 250 mA are 9.6 mW and 1.03% respectively, severally increasing by 405% and 249% compared to traditional one, meanwhile, the efficiency droop at 250 mA is also dramatically reduced from 42.2% to 16.6%. Further simulation analysis indicates that this graded MQB-EBL enhances the potential barrier height for electrons and meanwhile reduces that for holes, hence effectively suppresses the electron leakage, and at the same time significantly improves the hole injection efficiency. As a result, the whole performance of the LED with the proposed MQB-EBL is dramatically improved.

P104 One year failure rates for de novo ventriculo-peritonealshunts in under 3- month-old children

Objectives

Historically VPS failure and infection rates are higher for neonates than for older children. We compared our one year VPS failure and infection rates in under 3-month-olds with those of older children.

Design

A retrospective, single centre study comparing 1 year survival and infection rates of VPS in under 3-month-olds verses older children.

Subjects

58 children under 3 months of age underwent VPS insertion between January 2007 and December 2016.

Methods

Data was collected by three independent reviewers from electronic files and case notes. Data was analysed using descriptive statistics and one year shunt survival curves were produced.

Results

For children under 3 months there was a 29.3% one-year shunt failure rate, of which 2 were shunt infections (3.4%). In patients greater than 3 months, the shunt malfunction rate was 23.4% and the infection rate was 4.3%. There were no shunt-related mortalities in either group.

Conclusions

Children under 3-months-old undergoing VPS insertion should not automatically expect an increased 1 year failure or infection rate compared with older children. Reasons for this may be increased sub-specialisation, improved neonatal care and use of antibiotic impregnated catheters.

Cumulative cortisol exposure in the third trimester correlates with postpartum mothers' neural response to emotional interference

Prolonged stress affects the central nervous system, rendering individuals vulnerable to a wide range of mental health disorders. 76 healthy postpartum mothers were studied by means of functional magnetic resonance imaging within 6 days of childbirth. The subjects were required to perform the emotional Stroop task involving happy and anxious word-face combinations. Hair samples were collected to determine cumulative hair cortisol concentration (HCC) in the third trimester. HCC was found to be negatively correlated with the recruitment of the dorsal anterior cingulate cortex (ACC) and the midcingulate cortex (MCC). In response to the emotional interference of only anxious target faces, a negative correlation was seen between HCC and the bilateral orbitofrontal cortex, extending to the rostral ACC and the MCC. Women with lower HCC recruited brain areas relevant to emotional cognitive control, indicating that lower HCC helps preserve conflict monitoring and resolution capacities and thus benefits mental health in pregnancy.

Abstract P3-06-01: Clonal evolution and heterogeneity in breast tumors treated with neoadjuvant HER2-targeted therapy

Background: Understanding to what extent a breast tumor's genetic composition may change over the course of a few months of neoadjuvant therapy has implications for optimal therapeutic approach. However, genomic changes observed across treatment may result from either treatment-induced clonal evolution or geographically disparate sampling of a heterogeneous tumor. We sought to characterize the geographic heterogeneity in primary breast tumors, and to incorporate this information into analysis of clonal evolution with neoadjuvant therapy.

Methods: We assembled the largest cohort to date of multi-region (n=2-3) whole-exome sequenced (WES) or whole-genome sequenced untreated primary breast tumors with matched normal and adequate tumor purity for analysis: four tumors with data generated for this study and five tumors compiled from three previous studies. We also generated the first cohort of multi-region (n=2-6) WES breast tumors post-neoadjuvant HER2-targeted therapy and chemotherapy, sequencing one region from a pre-treatment diagnostic specimen, multiple regions from the post-treatment surgical specimen, and matched normal for five HER2+ breast tumors that did not achieve a pathologic complete response. We used an agent-based model of spatial tumor growth to investigate whether the mutational patterns we observed with treatment were consistent with pre-existing heterogeneity or treatment-induced selection.

Results: In untreated primary breast tumors, on average 30% (range 1-70%) of apparently clonal mutations from a single region were absent or rare in a second, spatially disparate region (high-frequency regional, or HFR). Intra-tumor heterogeneity was similar post-treatment (HFR 28%, range 10-54%), and was higher in breast tumors than in previously analyzed colon, brain, lung, and esophageal tumors. Simulation studies confirmed that with high heterogeneity as observed in breast tumors, analysis of one pre-treatment and one post-treatment region could not distinguish treatment-induced clonal evolution from pre-existing heterogeneity; however, obtaining at least two post-treatment regions allowed for detection of clonal shifts with treatment. Analysis of multi-region data revealed that clonal replacement occurred with neoadjuvant therapy in two of the five tumors. Candidate causes of therapeutic resistance included amplifications in CCND1, ERBB4, and MYC in one subclone, and functional protein-altering mutations in ERCC2, SMO, and WT1 in another. Mathematical modeling suggested that these putative resistant subclones comprised 0.02-12.5% of the overall pre-treatment cell population, substantially larger than previous estimates of resistant tumor clone size.

Conclusions: WES data from multiple regions of untreated and treated primary breast tumors revealed considerable heterogeneity that remained present throughout treatment with chemotherapy and HER2-targeted therapy, even while major clonal sweeps took place in a minority of tumors. Obtaining at least two samples for analysis from breast tumors post-neoadjuvant therapy may reveal the tumor's evolutionary path and, especially as increasing numbers of molecular and immune therapeutic targets are identified, inform new clinical strategies.

Citation Format: Caswell-Jin JL, McNamara K, Reiter JG, Sun R, Hu Z, Ma Z, Suarez CJ, Tilk S, Raghavendra A, Forte V, Chin S-F, Bardwell H, Provenzano E, Caldas C, Lang J, West R, Tripathy D, Press MF, Curtis C. Clonal evolution and heterogeneity in breast tumors treated with neoadjuvant HER2-targeted therapy [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 P3-06-01.

Abstract P1-15-02: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Schwab R, Clark A, Yau C, Wolf D, Chien AJ, Majure M, Ewing C, Wallace A, Roesch E, Helsten T, Forero A, Stringer-Reasor E, Vaklavas C, Nanda R, Jaskowiak N, Boughey J, Haddad T, Han H, Lee C, Albain K, Isaacs C, Elias A, Ellis E, Shah P, Lang J, Lu J, Tripathy D, Kemmer K, Yee D, Haley B, Korde L, Edmiston K, Northfelt D, Viscusi R, Khan Q, I-SPY 2 Consortium, Symmans WF, Perlmutter J, Hylton N, Rugo H, Melisko M, Wilson A, Singhrao R, Asare S, van't Veer L, DeMichele A, Berry D, Esserman L. Withdrawn [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 P1-15-02.

One year failure rates for de-novo ventriculo-peritoneal shunts in under 3-month-old children

Introduction: Ventriculo-peritoneal shunts (VPS) are still the mainstay treatment for hydrocephalus in children. It is generally accepted that VPS failure and infection rates are higher for neonates than for older children. We compared our 1-year failure and infection rates in under 3-month-old children compared with older children in our department. Results: We identified 58 children under 3 months of age who underwent VPS insertion between January 2007 and December 2016. They had a 29.3% (17) shunt failure rate over the first year. There were two confirmed shunt infections (3.4%). Discussion: The 1-year shunt failure rate at our institution for VPS insertion in children over 3 months is 26.1% and the infection rate is 4.3% (9). The literature suggests that the outcome for VPS in younger children is worse than for older children. Our work shows similar outcomes for all children compared to those under 3 months at time of VPS insertion alone. Conclusion: Children under 3-months-old undergoing VPS insertion should not automatically expect an increased 1-year failure or infection rate compared with older children. The reasons for this may be as a result of increased subspecialisation, the more widespread use of antibiotic-impregnated catheters and improved neonatal care.

Characterization of immune responses to anti-PD-1 mono and combination immunotherapy in hematopoietic humanized mice implanted with tumor xenografts

Background

The success of agents that reverse T-cell inhibitory signals, such as anti-PD-1/PD-L1 therapies, has reinvigorated cancer immunotherapy research. However, since only a minority of patients respond to single-agent therapies, methods to test the potential anti-tumor activity of rational combination therapies are still needed. Conventional murine xenograft models have been hampered by their immune-compromised status; thus, we developed a hematopoietic humanized mouse model, hu-CB-BRGS, and used it to study anti-tumor human immune responses to triple-negative breast cancer (TNBC) cell line and patient-derived colorectal cancer (CRC) xenografts (PDX).

Methods

BALB/c-Rag2^nullIl2rγ^nullSIRPα^NOD (BRGS) pups were humanized through transplantation of cord blood (CB)-derived CD34+ cells. Mice were evaluated for human chimerism in the blood and assigned into experimental untreated or nivolumab groups based on chimerism. TNBC cell lines or tumor tissue from established CRC PDX models were implanted into both flanks of humanized mice and treatments ensued once tumors reached a volume of ~150mm³. Tumors were measured twice weekly. At end of study, immune organs and tumors were collected for immunological assessment.

Results

Humanized PDX models were successfully established with a high frequency of tumor engraftment. Humanized mice treated with anti-PD-1 exhibited increased anti-tumor human T-cell responses coupled with decreased Treg and myeloid populations that correlated with tumor growth inhibition. Combination therapies with anti-PD-1 treatment in TNBC-bearing mice reduced tumor growth in multi-drug cohorts. Finally, as observed in human colorectal patients, anti-PD-1 therapy had a strong response to a microsatellite-high CRC PDX that correlated with a higher number of human CD8+ IFNγ+ T cells in the tumor.

Conclusion

Hu-CB-BRGS mice represent an in vivo model to study immune checkpoint blockade to human tumors. The human immune system in the mice is inherently suppressed, similar to a tumor microenvironment, and thus allows growth of human tumors. However, the suppression can be released by anti-PD-1 therapies and inhibit tumor growth of some tumors. The model offers ample access to lymph and tumor cells for in-depth immunological analysis. The tumor growth inhibition correlates with increased CD8 IFNγ+ tumor infiltrating T cells. These hu-CB-BRGS mice provide a relevant preclinical animal model to facilitate prioritization of hypothesis-driven combination immunotherapies.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0518-z) contains supplementary material, which is available to authorized users.