Real-World Experience of Intensity Modulated Radiation Therapy and Concurrent Chemotherapy for Anal Cancer with Long-Term Follow up and Clinical Outcomes

PURPOSE/OBJECTIVE(S)

The standard treatment for epidermoid anal cancer (AC) is concurrent chemoradiation (CRT). Here we present real world evidence of the safety and outcomes of AC patients managed by IMRT and concurrent chemotherapy at a single academic cancer center.

MATERIALS/METHODS

We retrospectively reviewed the outcomes of 180 AC patients treated with definitive CRT between 2011 and 2018. Patients were managed according to a prospectively designed protocol of IMRT with radiation dose escalated according to tumor stage: 50.4, 55.8 and 63 Gy for T1, T2 and T3/T4 disease respectively, and 36 Gy for elective nodal RT. Involved nodes were given the same dose based on T category. Concurrent chemotherapy consisted of two cycles of mitomycin C (MMC, 12 mg/m2) and 5-fluorouracil (5FU, 1000 mg/m2/day x 4 days) given on week 1 and 5. There was no planned treatment break. Univariate and multivariate analysis for outcomes were performed using Cox proportional hazard method and likelihood ratio statistics. Overall survival (OS) disease free (DFS), colostomy-free survival (CFS) and local failure rates (LFR) were described by Kaplan-Meier methods.

RESULTS

There were 128 female and 52 male patients with a median age of 64 (IQR 55-74). The median size of the primary was 4.0 cm (0.6-11.0 cm). There were 18 T1, 91 T2, 38 T3 and 33 T4 lesions; 50.6% (91/180) of the patients had N0 disease. Thirteen (7.2%) did not receive concurrent chemotherapy, and 16 (8.9%) failed to complete treatment as planned. Forty-three (23.9%) patients had a treatment gap >5 (6-33) days. Eighteen of 147 (12%) with T1-3 disease failed locally, LF was observed in 13/33 (39%) T4 lesions (P = 0.0002). The 5-year OS, DFS, CFS and LFR were 85.1%, 75.6%, 87.6% and 15.5% respectively. On multivariate analysis, increasing age and N+ disease were significant for worse OS, and increasing size of the primary tumor was the only significant factor for worse DFS, CFS and LFR. Grade ≥3 acute toxicities were observed in 42.8% of patients, with grade ≥3 neutropenia and febrile neutropenia observed in 18.9% and 13.9% of patients respectively. Six patients (3.3%) died of acute toxicities. Thirteen (7%) patients experienced grade ≥3 late toxicities.

CONCLUSION

Size of the primary appears to be the most important determinant of outcome following standard CRT using IMRT for AC. Despite IMRT, almost 1 in 4 patients required a treatment break, and over 40% experienced grade ≥3 acute toxicities including neutropenia and febrile neutropenia. Future studies with RT dose escalation or de-escalation, stratifying patients based on tumor size, HPV status and molecular markers are necessary to improve outcomes and decrease treatment related toxicity.

Differential Response in Quantitative MRI Parameters Detected in Head and Neck Cancer Patients Treated with Concurrent Immunotherapy during Hypo-Fractionated MR-gRT

PURPOSE/OBJECTIVE(S)

Recently, multiple clinical trials have demonstrated success of PD-1/PD-L1-targeted immune checkpoint inhibition (ICI) in recurrent and metastatic head and neck cancer (HNC). However, three large clinical trials combining PD-1/PD-L1-targeted ICI with RT or chemo-RT (CRT) in the definitive management of HNC have shown no benefit of combination therapy with ICI over RT or CRT alone. Our overarching hypotheses are: i) hypo-fractionation may ultimately better synergize with ICI compared to conventional RT regimens, and ii) immunologic changes in the tumor microenvironment may be detectable using quantitative MRI (qMRI) parameters collected during RT.

MATERIALS/METHODS

Seven patients treated with hypo-fractionated MR-guided RT of 50 Gy in 15 fractions (DEHART, NCT04477759) were included in the study. Four patients (Group 1) were treated with concurrent atezolizumab (a monoclonal antibody) and three patients (Group 2) were treated with RT alone. Daily DWI, T1 mapping, and T2 mapping sequences were acquired on a 1.5T MR-Linac in the idle time during adaptive plan generation. Median ADC, T1, T2, and Dslow (derived from b-values 150 and 550 s/mm2) values were extracted from physician-defined GTV and manually constructed posterior paraspinal muscle contours, the latter serving as a control. Wilcoxon signed rank tests were conducted using pre/post treatment data for each qMRI parameter.

RESULTS

GTV ADC, Dslow, T2, and T1 increased for both patient groups over the course of treatment with significant differences in ADC, Dslow, and T2 detected between fractions 1 and 15 for all patients studied (p = 0.0156, p = 0.0156, and p = 0.0469, respectively). No significant differences were detected in control qMRI parameters pre/post treatment. No significant differences in ADC, Dslow, and T2 were detected between groups' fractions 1 and 15 in these small cohorts. However, interestingly, we observed a differential change in the increase of median GTV T2 and Dslow values during fractions 10-12 in Group 1 compared to Group 2, suggesting this time interval may prime the anti-tumor immune response.

CONCLUSION

Combining hypo-fractionated RT with ICI leads to a differential response in quantitative MRI (qMRI) parameters in HNC patients. These results suggest that qMRI parameter changes ten days following the start of RT may reflect a critical juncture in the anti-tumoral immune response when ICI is combined with hypo-fractionated RT.

Analysis of Microbiomes from Ultra-Low Biomass Surfaces Using Novel Surface Sampling and Nanopore Sequencing

The rapid assessment of microbiomes from ultra-low biomass environments such as cleanrooms or hospital operating rooms has a number of applications for human health and spacecraft manufacturing. Current techniques often employ lengthy protocols using short-read DNA sequencing technology to analyze amplified DNA and have the disadvantage of a longer analysis time and lack of portability. Here, we demonstrate a rapid (~24 hours) on-site nanopore-based sequencing approach to characterize the microbiome of a NASA Class 100K cleanroom where spacecraft components are assembled. This approach employs a modified protocol of Oxford Nanopore's Rapid PCR Barcoding Kit in combination with the recently developed Squeegee-Aspirator for Large Sampling Area (SALSA) surface sampling device. Results for these ultra-low biomass samples revealed DNA amplification ~1 to 2 orders of magnitude above process control samples and were dominated primarily by Paracoccus and Acinetobacter species. Negative control samples were collected to provide critical data on background contamination, including Cutibacerium acnes, which most likely originated from the sampling reagents-associated microbiome (kitome). Overall, these results provide data on a novel approach for rapid low-biomass DNA profiling using the SALSA sampler combined with modified nanopore sequencing. These data highlight the critical need for employing multiple negative controls, along with using DNA-free reagents and techniques, to enable a proper assessment of ultra-low biomass samples.

The Development of a 3D Printer-Inspired, Microgravity-Compatible Sample Preparation Device for Future Use Inside the International Space Station

Biological testing on the International Space Station (ISS) is necessary in order to monitor the microbial burden and identify risks to crew health. With support from a NASA Phase I Small Business Innovative Research contract, we have developed a compact prototype of a microgravity-compatible, automated versatile sample preparation platform (VSPP). The VSPP was built by modifying entry-level 3D printers that cost USD 200-USD 800. In addition, 3D printing was also used to prototype microgravity-compatible reagent wells and cartridges. The VSPP's primary function would enable NASA to rapidly identify microorganisms that could affect crew safety. It has the potential to process samples from various sample matrices (swab, potable water, blood, urine, etc.), thus yielding high-quality nucleic acids for downstream molecular detection and identification in a closed-cartridge system. When fully developed and validated in microgravity environments, this highly automated system will allow labor-intensive and time-consuming processes to be carried out via a turnkey, closed system using prefilled cartridges and magnetic particle-based chemistries. This manuscript demonstrates that the VSPP can extract high-quality nucleic acids from urine (Zika viral RNA) and whole blood (human RNase P gene) in a ground-level laboratory setting using nucleic acid-binding magnetic particles. The viral RNA detection data showed that the VSPP can process contrived urine samples at clinically relevant levels (as low as 50 PFU/extraction). The extraction of human DNA from eight replicate samples showed that the DNA extraction yield is highly consistent (there was a standard deviation of 0.4 threshold cycle when the extracted and purified DNA was tested via real-time polymerase chain reaction). Additionally, the VSPP underwent 2.1 s drop tower microgravity tests to determine if its components are compatible for use in microgravity. Our findings will aid future research in adapting extraction well geometry for 1 g and low g working environments operated by the VSPP. Future microgravity testing of the VSPP in the parabolic flights and in the ISS is planned.

Zero the hero: Evidence for involvement of the ventromedial prefrontal cortex in affective bias for free items

Recent evidence from psycho-economics shows that when the price of an item decreases to the extent that it becomes available for free, one can observe a remarkable increase of subjective utility toward this item. This phenomenon, which is not observed for any other price but zero, has been termed the zero-price effect (ZPE). The ZPE is attributed to an affective heuristic where the positive affect elicited by the free status of an item provides a mental shortcut biasing choice towards that item. Given that the ZPE relies on affective processing, a key role of the ventromedial prefrontal cortex (vmPFC) has been proposed, yet neuroscientific studies of the ZPE remain scarce. This study aimed to explore the role of the vmPFC in the ZPE using a novel, within-subject assessment in participants with either an acquired (lesion patients) or degenerative (behavioural-variant frontotemporal dementia patients) lesion of the vmPFC, and age-matched healthy controls. All participants were asked to make a series of choices between pairs of items that varied in price. One choice trial involved an equal decrease of both item prices, such that one of the items was priced zero. In contrast to controls, patients with both vmPFC-lesion and behavioural-variant frontotemporal dementia showed marked reductions in zero-related changes of preference in pairs of gift-cards, but not for pairs of food items. Our findings suggest that affective evaluations driving the ZPE are altered in patients with focal or degenerative damage to the vmPFC. This supports the notion of a key role of the vmPFC in the ZPE and, more generally, the importance of this region in value-based affective decision-making. Our findings also highlight the potential utility of affective heuristic tasks in future clinical assessments.

Caring for carers: A virtual psychosocial supervision intervention to improve the quality and sustainability of mental health and psychosocial support in humanitarian contexts

Introduction

Mental health and psychosocial support (MHPSS) staff in humanitarian settings have limited access to clinical supervision and are at high risk of experiencing burnout. We previously piloted an online, peer-supervision program for MHPSS professionals working with displaced Rohingya (Bangladesh) and Syrian (Turkey and Northwest Syria) communities. Pilot evaluations demonstrated that online, peer-supervision is feasible, low-cost, and acceptable to MHPSS practitioners in humanitarian settings.

Objectives

This project will determine the impact of online supervision on i) the wellbeing and burnout levels of local MHPSS practitioners, and ii) practitioner technical skills to improve beneficiary perceived service satisfaction, acceptability, and appropriateness.

Methods

MHPSS practitioners in two contexts (Bangladesh and Turkey/Northwest Syria) will participate in 90-minute group-based online supervision, fortnightly for six months. Sessions will be run on zoom and will be co-facilitated by MHPSS practitioners and in-country research assistants. A quasi-experimental multiple-baseline design will enable a quantitative comparison of practitioner and beneficiary outcomes between control periods (12-months) and the intervention. Outcomes to be assessed include the Kessler-6, Harvard Trauma Questionnaire and Copenhagen Burnout Inventory and Client Satisfaction Questionnaire-8.

Results

A total of 80 MHPSS practitioners will complete 24 monthly online assessments from May 2022. Concurrently, 1920 people receiving MHPSS services will be randomly selected for post-session interviews (24 per practitioner).

Conclusions

This study will determine the impact of an online, peer-supervision program for MHPSS practitioners in humanitarian settings. Results from the baseline assessments, pilot evaluation, and theory of change model will be presented.

Disclosure

No significant relationships.

Loop-Mediated Isothermal Amplification of Trypanosoma cruzi DNA for Point-of-Care Follow-Up of Anti-Parasitic Treatment of Chagas Disease

A loop-mediated isothermal amplification assay was evaluated as a surrogate marker of treatment failure in Chagas disease (CD). A convenience series of 18 acute or reactivated CD patients who received anti-parasitic treatment with benznidazole was selected-namely, nine orally infected patients: three people living with HIV and CD reactivation, five chronic CD recipients with reactivation after organ transplantation and one seronegative recipient of a kidney and liver transplant from a CD donor. Fifty-four archival samples (venous blood treated with EDTA or guanidinium hydrochloride-EDTA buffer and cerebrospinal fluid) were extracted using a Spin-column manual kit and tested by T. cruzi Loopamp kit (Tc-LAMP, index test) and standardized real-time PCR (qPCR, comparator test). Of them, 23 samples were also extracted using a novel repurposed 3D printer designed for point-of-care DNA extraction (PrintrLab). The agreement between methods was estimated by Cohen's kappa index and Bland-Altman plot analysis. The T. cruzi Loopamp kit was as sensitive as qPCR for detecting parasite DNA in samples with parasite loads higher than 0.5 parasite equivalents/mL and infected with different discrete typing units. The agreement between qPCR and Tc-LAMP (Spin-column) or Tc-LAMP (PrintrLab) was excellent, with a mean difference of 0.02 [CI = -0.58-0.62] and -0.04 [CI = -0.45-0.37] and a Cohen's kappa coefficient of 0.78 [CI = 0.60-0.96] and 0.90 [CI = 0.71 to 1.00], respectively. These findings encourage prospective field studies to validate the use of LAMP as a surrogate marker of treatment failure in CD.

Quantifying Contact Patterns: Development and Characteristics of the British Columbia COVID-19 Population Mixing Patterns Survey

Purpose

Several non-pharmaceutical interventions such as physical distancing, self-isolation, a stay-at-home order, hand washing, and schools and businesses closures were implemented in British Columbia (BC) following the first lab-tested case of COVID-19 on January 26, 2020. These interventions were aimed at minimizing in-person contacts that could potentially lead to new COVID-19 infections. The BC COVID-19 Population Mixing Patterns survey (BC-Mix) was established as a surveillance system to measure behaviour and contact patterns in BC over time to inform the timing of the easing/re-imposition of control measures. We describe the BC-Mix survey design and the demographic characteristics of respondents.

Methods & Materials

The ongoing repeated online survey was launched in September 2020. Participants are recruited through a variety of social media platforms including Instagram, Facebook, YouTube, and community group mailing lists. A follow up survey is sent to participants two to four weeks after completing the first iteration. Survey responses are weighted to BC's population by age, sex, geography, and ethnicity to obtain generalizable estimates. A survey completion rate of at least 33% AND a valid response for the sex questionnaire item AND a valid response for age questionnaire item were required for inclusion in weighting and further analysis. Additional indices such as material and social deprivation index, and residential instability are generated using census and location data.

Results

As of June 14, 2021, over 58,000 residents of BC had participated in the survey of which 31,007 survey responses were eligible for analysis. Of the eligible participants, about 60% provided consent for monthly follow up and about 26% provided their personal health numbers for linkage with other healthcare utilization databases. Approximately 51% were females 39% were 55 years or older, 63% identified as white or not a visible minority and 48% had at least a university degree.

Conclusion

The pandemic response is best informed by surveillance systems capable of timely assessment of behaviour patterns. BC-Mix survey respondents represented a large cohort of British Columbians providing near real-time information on behavioural and contact patterns in BC. Data from the BC-Mix survey continues to inform provincial COVID-19-related control measures.

A98 FECAL LEUKOCYTE ESTERASE: AN ALTERNATIVE BIOMARKER TO FECAL CALPROTECTIN IN INFLAMMATORY BOWEL DISEASE

Background

Fecal calprotectin (FC) is a non-invasive biomarker used in inflammatory bowel disease (IBD) management and risk stratification of non-specific gastrointestinal symptoms. Leukocyte esterase is an inexpensive and widely available point-of-care inflammatory marker present on urinalysis test strips.

Aims

We aim to assess the diagnostic accuracy of fecal leukocyte esterase (FLE) relative to FC and endoscopy and demonstrate its use as an alternative biomarker for IBD.

Methods

In this prospective cohort study, 70 patients who had FC ordered as part of standard clinical care also received FLE testing. FLE levels were compared to various FC cut-off values, endoscopy and pathology findings as gold standard.

Results

As the FC cut-off increased from 50 to 500 μg/g, FLE sensitivity increased from 67% to 95% while the specificity decreased from 86% to 76%. The area under the receiver operating characteristic (AUROC) increased from 0.79 to 0.90. An FLE of ≥1+ had the best test characteristics. Amongst patients who underwent endoscopic evaluation, FLE demonstrated an identical sensitivity (75%) and specificity (86%) to FC in predicting endoscopic inflammation. AUROC was 0.80 for FLE and 0.85 for FC with an optimal cut-off of ≥2+ and 301 μg/g, respectively. When used to distinguish between active IBD and no/inactive IBD patients, FLE had a sensitivity of 84% and specificity of 90%, comparable to the 84% and 83%, respectively, of FC. AUROC was 0.88 for FLE and 0.91 for FC with an optimal cut-off of ≥2+ and 145 μg/g, respectively

Conclusions

FLE demonstrates adequate correlation and comparable accuracy to FC in predicting endoscopic inflammation and distinguishing between patients with active versus inactive IBD.

Funding Agencies

None

A29 ALBUMIN UTILISATION AT A TERTIARY CARE HOSPITAL

Background

Albumin is a colloidal solution with usage guided by recommendations from Canadian Blood Services (CBS). In Ontario, rates of albumin use increased substantially from 2012 to 2018 despite the lack of development of new indications for using over this time frame. Further, we recently found that >50% of albumin usage in patients with cirrhosis were non-evidence based. Albumin usage in other patient populations is not well described.

Aims

Our aim was to describe overall usage of albumin stratified by clinical setting, clinical indication, and dosage at a tertiary care hospital.

Methods

We retrospectively identified all albumin prescriptions during two randomly selected non-consecutive months between 2018 and 2019 at Kingston Health Sciences Centre. Data was abstracted from each hospital chart for indication, prescriber specialty, location of patient, amount of albumin ordered, and concentration (5% or 25%). Albumin prescriptions were then defined as either evidence-based or non-evidence based on published literature and guidelines. Overall cost for albumin during the study period was determined based on CBS pricing ($51.47/ 25gms).

Results

A total of 699 albumin prescriptions were dispensed to 317 individuals over December 2018 and May 2019, with a total of 38,458 grams used. Overall, 36% was prescribed for evidence-based indications. The most common indication was plasmapheresis (32%), non-sepsis volume resuscitation (23%), and cardiac surgery (17%). The majority of albumin was prescribed in dialysis unit (32%), ICU (23%), and cardiac sciences unit (11%). The largest prescribers of albumin were intensivists (26%), followed by nephrologists (17%), and cardiac surgeons (15%). There were differences in utilization based on concentration of albumin. Despite limited evidence of benefit, 25% albumin and 5% albumin were used excessively for volume resuscitation and cardiac surgery respectively. When used for an evidence-based indication, the dosing was incorrect in 45% of orders. A total of $79,176 was spent on albumin during the study period. Importantly, only $28,494 was spent on evidence-based indications with appropriate dosage and concentration.

Conclusions

Overall, there is significant albumin use for indications lacking substantial evidence. This study identifies the clinical contexts in which there is opportunity to reduce non-evidence-based albumin usage and cut unnecessary expenditure. Targeted quality improvement initiatives are underway.

Funding Agencies

None

Abstract ES8-4: Axillary management in upfront surgery - staging, local control or both?

Axillary management in women undergoing upfront surgery for operable breast cancer has changed dramatically over the last several decades. Axillary lymph node dissection (ALND), a procedure that was historically used in both clinically node negative and node positive patients to stage the axilla and optimize locoregional control, is associated with the potential for significant long-term morbidity in the form of upper extremity lymphedema, paresthesia, and shoulder dysfunction. Efforts to minimize the morbidity associated with ALND, as well as the recognition that only a minority of patients with clinically node negative disease are found to have nodal metastases at the time of axillary surgery, prompted the development and validation of sentinel lymph node biopsy (SLNB). In women who are clinically node negative, SLNB has been shown to accurately stage the axilla without compromising oncologic outcomes, identifying nodal disease in up to 30% of cases. The application of clinical trial data from Z0011 and AMAROS in T1-T2 breast cancer with 1-2 positive lymph nodes undergoing breast conservation allow for omission of completion ALND with no impact on locoregional control or survival. The ongoing POSNOC trial (NCT02401685) will further determine whether women with T1-T2 disease undergoing breast conservation or mastectomy require directed axillary treatment in the form of ALND or axillary radiation to minimize the risk of axillary failure. An altogether omission of axillary staging in clinically node negative breast cancer remains an area of evolving interest, with CALGB 9343 trial data supporting this approach in older women with stage I estrogen-receptor positive (ER+) HER2- breast cancer. Trials examining the omission of SLNB in other select patient populations with negative axillary imaging are the subject of ongoing investigation. At present, prognostic information derived from SLNB for clinically node negative women undergoing upfront surgery for early-stage triple negative and HER2+ breast cancer, premenopausal ER+HER2- breast cancer, and BRCA1/2-associated breast cancer remain important for adjuvant systemic therapy decision-making.

Citation Format: S Wong. Axillary management in upfront surgery - staging, local control or both? [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr ES8-4.

ECG changes in psychiatric patients on psychotropic medications

Funding Acknowledgements

Type of funding sources: None.

Background

Suicide and euthanasia accounts for 14.3% of deaths in those with psychiatric conditions. The rest are attributed to preventable causes such as cardiovascular disease, respiratory disease, and infections. Several psychotropic medications have been associated with sudden death due to their effect on prolonging QT interval, resulting in the development of a polymorphic ventricular arrhythmia, Torsades de Pointes (TdP). TdP may be self-limiting or lead to sudden cardiac arrest and death.

Purpose

This study aims to evaluate the cardiotoxic effects of psychotropic medications.

Method

This is a descriptive retrospective study of patients submitted to the local psychiatric wards within one year. Patients with psychotropic drug prescriptions were included while patients below 18 years old, pregnant, or did not have ECG performed were excluded. The control group consisted of sex- and age- matched patients with ECG conducted for occupational health purposes. Multiple regression models were conducted to investigate the predictors of significant ECG differences.

Result

Of the 154 psychiatric inpatients admitted, exclusions were 44 patients due to exclusion criteria and 19 patients due to difficulty in physical file access. The study population (n = 91) had a mean age of 36.7 years old with 40.7% female and 59.3% male. The predominant diagnoses were schizophrenia and delusional disorders (58.2%). 86 psychiatric patients (94.5%) were prescribed antipsychotic drugs (APD).

A significantly higher proportion of psychiatric patients has a history of smoking (p < 0.001), alcohol consumption (p = 0.001), and illicit drug use (p < 0.001). They also exhibited significantly more co-morbid illnesses including hypertension (p = 0.022), hyperlipidaemia (p = 0.013), diabetes (p = 0.026) and thyroid disease (p = 0.023) than the control population.

Psychiatric patients had a significantly higher mean heart rate (79.9 vs 69.6 ms; p < 0.001) and QTc interval (452.2 vs 418.6ms; p < 0.001). Mean QTc interval was significantly longer for psychiatric patients in both male (454.2 vs 414.5ms; p < 0.001) and female (449.3 vs 425.6 ms; p = 0.029) gender. Psychotropic drug use is a significant predictor for both prolonged heart rate (p < 0.001) and prolonged QTc interval (p < 0.001). Electrolyte imbalance is a significant predictor of prolonged QTc interval only (p = 0.036). One year follow of both groups detected only 1 psychiatric patient with palpitation.

Conclusion

Psychiatric patients on psychotropic medications have a longer baseline heart rate and QTc interval, which was not associated with MACE at 1 year. None of the underlying comorbidities and lifestyle choices were significant predictors of this. Electrolyte abnormalities and psychotropic drug use significantly predicted QTc prolongation. However, these findings were largely driven by APD use. A follow-up study of a longer period is recommended to investigate whether patients with prolonged QTc interval are of higher risk of MACE occurrence.