Characterizing prostate cancer risk through multi-ancestry genome-wide discovery of 187 novel risk variants

The transferability and clinical value of genetic risk scores (GRSs) across populations remain limited due to an imbalance in genetic studies across ancestrally diverse populations. Here we conducted a multi-ancestry genome-wide association study of 156,319 prostate cancer cases and 788,443 controls of European, African, Asian and Hispanic men, reflecting a 57% increase in the number of non-European cases over previous prostate cancer genome-wide association studies. We identified 187 novel risk variants for prostate cancer, increasing the total number of risk variants to 451. An externally replicated multi-ancestry GRS was associated with risk that ranged from 1.8 (per standard deviation) in African ancestry men to 2.2 in European ancestry men. The GRS was associated with a greater risk of aggressive versus non-aggressive disease in men of African ancestry (P = 0.03). Our study presents novel prostate cancer susceptibility loci and a GRS with effective risk stratification across ancestry groups.

Significance of Radiomics in Predicting Local Control for Patients with Malignant Liver Tumors Treated Using Stereotactic Body Radiotherapy

PURPOSE/OBJECTIVE(S)

We routinely deliver Stereotactic Body Radiotherapy (SBRT) in malignant liver tumors using planning computed tomography (CT) and Magnetic Resonance Images (MRI) to aid target definition. In this study, we extracted radiomic features from the MR images to predict local control (LC) post-SBRT.

MATERIALS/METHODS

We retrospectively analyzed patients with either hepatocellular cancers (HCCs) or liver metastases (Mets) treated with SBRT between Aug 2014 and Aug 2020. All patients had CT simulation followed by 1.5 Tesla planning MRI in treatment position. Contrast enhanced T1 VIBE and T2 Haste MR sequences were registered with planning CT for target definition. Radiomic features were extracted from Gross Tumor Volumes (GTV) masked out of 60 seconds post contrast T1 VIBE MR images using the Radiomics calculator tool RaCaT. The output included 480 (408 textural, 50 intensity and 22 morphological) features for each target. Principal Component Analysis of the outputs obtained from all the targets yielded 20 radiomic feature clusters after computational prioritization. These clusters were correlated to LC outcomes at various time points post-SBRT. LC was defined as non-progressive disease. Accuracy of predictions was measured by area under (AUC) receiver operating characteristic curve. Cox regression analysis was done to find univariate and multivariate clinical [HCCs vs. Mets, single vs. multiple lesions, previous local therapy (yes vs. no), GTV volume (≤40 vs. >40 cc)], radiomic and dosimetric predictors (continuous) of LC.

RESULTS

In total, 97 patients received SBRT to 122 lesions. The median dose prescribed was 45 Gy (range, 30-50 Gy). Median age was 69 years (interquartile range, IQR 61-73 yrs.). 59 patients had HCCs and 38 had Mets. 24 lesions had prior ablative therapy. 75 patients had one target, and 22 had multiple targets. Median GTV was 43.5 cc (IQR 23.4-78.6 cc). Median follow up was 16.6 months (IQR 9.7-27.2 mths). Median LC was 13.6 months (IQR 8.0-23.5 mths). On univariate analysis, histology (HCCs vs. Mets; Hazard ratio (HR) 2.9, 95% CI 1.4-6.4; p < 0.006), radiomic clusters (p < 0.006) and the max., mean, and min. doses to GTV and Planning Target Volumes correlated with improved LC (all p-values < 0.05). On multivariate analysis, histology (HCCs vs. Mets; HR 4.4, 95% CI 1.6-12.3; p = 0.004), radiomic clusters (p = 0.034) and prescription dose (p = 0.048) were significant covariates. Specifically, the 20 radiomic clusters were predictive of LC, and the accuracy of predictions showed promise with AUC values of 0.74, 0.80, and 0.81 at 12, 24, and 36 months post-SBRT, respectively. AUC values for LC in HCCs vs. Mets at 12, 24, and 36 months were 0.83, 0.77, and 0.70, and 0.66, 0.77, and 0.88, respectively.

CONCLUSION

MR-based radiomics predict LC post-SBRT in patients with malignant liver tumors. Further research focused on independent validation of the model is required to explore its clinical use.

Long-Term Patient-Reported Quality of Life of Anal Cancer Survivors Treated With Intensity Modulated Radiation Therapy and Concurrent Chemotherapy: Results From a Prospective Phase II Trial

PURPOSE

Intensity modulated radiation therapy (IMRT) has confirmed its superiority in improving acute treatment-related toxicities in anal cancer, without compromising tumor control. However, the effect of IMRT on long-term quality of life (QOL) is poorly documented. The study prospectively evaluated the long-term patient-reported QOL after IMRT-based chemoradiation in anal cancer.

METHODS AND MATERIALS

Fifty-eight patients treated with IMRT and concurrent 5 fluorouracil/mitomycin-C were enrolled in the study. A prespecified secondary endpoint was prospective evaluation of long-term QOL. Fifty-four patients underwent QOL evaluation at baseline, after treatment, and during follow-up until 60 months, with European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 (EORTC QLQ-C30) scales and the Colorectal Cancer-Specific Quality Of Life Questionnaire (QLQ-CR29) scales. The QOL scores at baseline and posttreatment periods were compared.

RESULTS

For QLQ-C30, at 60 months, the mean scores of global health status, all functional scales, and all symptoms except diarrhea had improved, indicating normalization of QOL. Clinically and statistically significant improvements in the global health status (15.4; P = .003), role functioning (19.3; P = .0017), emotional functioning (18.9; P = .008), and social functioning (29.8; P ≤ .001) were observed. Diarrhea persisted as a concern over the years (P = .172). For European Organization for Research and Treatment of Cancer QLQ-CR29, rectal pain (-38.6; P = .001), mucous or blood discharge per rectum (-22.8; P = .005), and perianal soreness (-37.3; P ≤ .001) were improved both clinically and statistically. Clinically significant fecal leakage was reported by 16% of patients (5.6; P = .421). Volumes receiving 45 and 54 Gy were independent predictors for fecal incontinence. Clinically and statistically significant urinary incontinence occurred in 21% of patients (17.5; P = .014). Deterioration of dyspareunia was clinically significant (26.7; P = .099) at 60 months.

CONCLUSIONS

Compared with historical data, IMRT is associated with reduced long-term effects on QOL. The majority of patients treated with IMRT experienced clinically significant recovery of function and improvement in QOL over 5 years after completion of treatment. Specific toxicities such as chronic diarrhea, fecal incontinence, and urinary and sexual dysfunction were primarily responsible for deterioration of the long-term QOL. Future research aimed at reducing such toxicities is needed to further improve long-term QOL in anal cancer.

Clinical efficacy of the virtual fracture clinic: analysis of 17,269 referrals by type of injury

INTRODUCTION

Numerous studies have deemed the virtual fracture clinic (VFC) model to be both cost and clinically effective. However, very few of these studies have analysed the type of injuries seen in the VFC. The objectives of this study were to assess the clinical effectiveness of the VFC and analyse the types of injuries that lead to patients re-presenting in the face-to-face fracture clinic after being discharged virtually.

METHODS

This is a retrospective study analysing 17,269 patients referred to the VFC between September 2017 and February 2020. Data regarding the type of presenting injury were collected to understand which injuries required further management after being discharged virtually. Patient clinic letters provided data regarding the purpose and outcomes of VFC referrals as well as face-to-face appointments. Theatre lists were cross-referenced to extract data regarding surgical management.

RESULTS

In total, 57.37% (9,908) patients were discharged virtually. Of these patients, 92.52% were discharged successfully and 7.48% re-presented to the fracture clinic: 98.11% were managed conservatively and 1.88% required surgery. The highest number of failed discharges were for distal radius fractures (109, 14.69%). Face-to-face follow-up in fracture clinic was requested for 37.06% (6,400) of patients; 4.98% of them required surgical intervention. Some 5.56% (961) of referrals were removed from our analysis: 807 were inappropriate referrals and 154 were deemed suitable for multidisciplinary team discussion. The trust has saved an average of £702,205 annually since introduction of the VFC.

CONCLUSIONS

The VFC model delivers as promised in terms of clinical efficacy and cost management. Injury types showing higher numbers of unsuccessful discharges could benefit from having modified management pathways.

Pseudogout Causing Thoracic Outlet Syndrome

Introduction/Objective

Calcium pyrophosphate dihydrate (CPPD) crystal deposition or pseudogout is a common entity encountered in routine practice. However, when a common entity presents in uncommon locations with unusual clinical manifestations, it creates a diagnostic conundrum. Pseudogout commonly occurs in the joint extremities including knee, wrist, shoulder, hip, and ankle joints. The sternoclavicular joint is a rare site for pseudogout with very low incidence. To the best of our knowledge, there are only two other cases of pseudogout mimicking a tumor causing vascular obstruction in the literature.

Methods/Case Report

A 63 year old male presented with an enlarging supraclavicular mass. A computed tomography angiography scan of the chest revealed an irregular soft tissue mass located behind the medial clavicle measuring up to 4 cm and was noted to compress and partially occlude the right subclavian vein. Partial occlusion of right axillary vein, right internal jugular vein, and right brachiocephalic vein were also noted on imaging. The venous compression led to outflow obstruction and resultant recurrent deep vein thrombosis of the right upper extremity. Due to compression by the mass, he required stenting of the right subclavian vein which unfortunately reoccluded. Subsequently, the patient underwent excision of the mass and partial resection of the first rib with decompression of the thoracic outlet. The excisional biopsy revealed dense rhomboid-shaped CPPD crystal depositions in irregular nodules within a background of fibrinoid material and fragments of unremarkable cartilaginous tissue. The patients compressive symptoms were relieved following the excision. While clinically and radiologically the mass was concerning for a malignant tumor, histological examination provided a definitive diagnosis of a benign process.

Results (if a Case Study enter NA)

NA.

Conclusion

Pseudogout is a rare mimicker of bone and soft tissue tumors and differentiation from an enchondroma, or grade 1 chondrosarcoma becomes a challenge especially on small tissue biopsies and is a possible diagnostic pitfall.

Tumor Volume Predicts for Pathologic Complete Response in Rectal Cancer Patients Treated With Neoadjuvant Chemoradiation

OBJECTIVES

Nonoperative management (NOM) of locally advanced rectal cancer is an emerging approach allowing patients to preserve their anal sphincter. Identifying clinical factors associated with pathologic complete response (pCR) is essential for physicians and patients considering NOM.

MATERIALS AND METHODS

In total, 412 locally advanced rectal cancer patients were included in this retrospective analysis. Tumor volumes were derived from pretreatment MRI. Clinical parameters such as tumor volume, stage, and location were analyzed by univariate and multivariate analysis, against pCR. A receiver operator characteristic curve was generated to identify a tumor volume cut-off with the highest clinically relevant Youden index for predicting pCR.

RESULTS

Seventy-five of 412 patients (18%) achieved pCR. A tumor volume threshold of 37.3 cm 3 was identified as predictive for pCR. On regression analysis, a tumor volume >37.3 cm 3 was associated with a greater than 78% probability of not achieving pCR. On multivariate analysis, a GTV <37.3 cm 3 [odds ratio (OR)=3.7, P <0.0001] was significantly associated with an increased pCR rate, whereas tumor length > 4.85 cm was associated with pCR on univariate (OR=3.03, P <0.01) but not on multivariate analysis (OR=1.45, P =0.261). Other clinical parameters did not impact pCR rates.

CONCLUSIONS

A tumor volume threshold of 37.3 cm 3 was identified as predictive for pCR in locally advanced rectal cancer patients receiving neoadjuvant chemoradiation. Tumors above this volume threshold corresponded to a greater than 78% probability of not achieving pCR. This information will be helpful at diagnosis for clinicians who are considering potential candidates for NOM.

Prostate cancer risk stratification improvement across multiple ancestries with new polygenic hazard score

BACKGROUND

Prostate cancer risk stratification using single-nucleotide polymorphisms (SNPs) demonstrates considerable promise in men of European, Asian, and African genetic ancestries, but there is still need for increased accuracy. We evaluated whether including additional SNPs in a prostate cancer polygenic hazard score (PHS) would improve associations with clinically significant prostate cancer in multi-ancestry datasets.

METHODS

In total, 299 SNPs previously associated with prostate cancer were evaluated for inclusion in a new PHS, using a LASSO-regularized Cox proportional hazards model in a training dataset of 72,181 men from the PRACTICAL Consortium. The PHS model was evaluated in four testing datasets: African ancestry, Asian ancestry, and two of European Ancestry-the Cohort of Swedish Men (COSM) and the ProtecT study. Hazard ratios (HRs) were estimated to compare men with high versus low PHS for association with clinically significant, with any, and with fatal prostate cancer. The impact of genetic risk stratification on the positive predictive value (PPV) of PSA testing for clinically significant prostate cancer was also measured.

RESULTS

The final model (PHS290) had 290 SNPs with non-zero coefficients. Comparing, for example, the highest and lowest quintiles of PHS290, the hazard ratios (HRs) for clinically significant prostate cancer were 13.73 [95% CI: 12.43-15.16] in ProtecT, 7.07 [6.58-7.60] in African ancestry, 10.31 [9.58-11.11] in Asian ancestry, and 11.18 [10.34-12.09] in COSM. Similar results were seen for association with any and fatal prostate cancer. Without PHS stratification, the PPV of PSA testing for clinically significant prostate cancer in ProtecT was 0.12 (0.11-0.14). For the top 20% and top 5% of PHS290, the PPV of PSA testing was 0.19 (0.15-0.22) and 0.26 (0.19-0.33), respectively.

CONCLUSIONS

We demonstrate better genetic risk stratification for clinically significant prostate cancer than prior versions of PHS in multi-ancestry datasets. This is promising for implementing precision-medicine approaches to prostate cancer screening decisions in diverse populations.

Patterns and predictors of relapse in Merkel cell carcinoma: Results from a population-based study

BACKGROUND AND PURPOSE

Prospective data evaluating the role of adjuvant radiotherapy (RT) for Merkel Cell Carcinoma(MCC) is lacking. To better understand the efficacy of adjuvant RT, a population-based patterns of failure study was conducted.

METHODS

We identified MCC patients treated from 1988 to 2018.Primary outcome measures were recurrence-free survival (RFS), overall survival (OS) and MCC-specific survival (MCC-SS). Charlson Co-morbidity Index (CCI) was also calculated.

RESULTS

217 patients with mean age 79 (range: 33-96) were analyzed. The median follow-up was 40 months. Treatments were: surgery(S) alone (n = 101, 45%) or S + RT(n = 116, 55%).Local recurrence (LR) was low in stage I (n = 6, 6.5%) with clear margin of ≥1 cm, negative sentinel lymph node biopsy (SLNB) without high-risk factors, irrespective of adjuvant RT. Tumor size ≥ 2 cm (HR:2.95; p = 0.024) and immunosuppression(HR:3.98; p = 0.001) were associated with high risk of nodal failure. Adjuvant RT was associated with significant reduction in regional failure (HR:0.36; p = 0.002). Distant metastases (DM) were infrequent in stage I (4/90) and stage II (4/34), compared to stage III (32/93). Adjuvant RT improvedRFS but did not influence MCC-SS and OS. CCI was a significant predictor of OS.

CONCLUSIONS

Adjuvant RT improvedRFS, withoutimpact on MCC-SS and OS. Co-morbidity rather than RT influenced OS. Adjuvant RT may be avoided instage I patients with negative SLNB and no associated high-risk factors. Prophylactic RNI could be considered in stage II with high risk features, inspite of negative SLNB. Stage III patients benefited from adjuvant RNI, but no impact on prevention of DM.

455 A Case of An Unusual Penetrating Brain Injury

Introduction

Penetrating brain injuries (PBI) are less common than closed head traumas. Interest in frontal lobe injuries dates back to 1848’s famous Phineas Gage incident. Here, we report a case of a construction worker, who showed a remarkable neuropsychiatric outcome following a workplace accident.

Case Presentation

45year old gentleman came with complaint of a foreign body accidentally lodged in his forehead. He had no neurological deficits or CSF leak. X-ray revealed that a 5.5cm metallic screw was penetrating his skull, headfirst; CT revealed that approximately 3cm of the screw was in the frontal sinus. He was given antiepileptics and antibiotics prophylactically. Surgically the screw was removed by raising a bone flap and mobilizing the screw carefully by cutting the dura and adequate irrigation, causing minimal damage to the brain parenchyma. The dural deficits were repaired and the frontal sinus was canalized, then a drain was placed, and the patient was shifted to ICU for postoperative monitoring.

Discussion

It is important to prognosticate PBI as they can have neurological deficits that may be lifelong. Understanding the mechanism of injury, aggressive medical management and immediate surgical intervention may lead to improved outcomes. A foreign object of the size of 5.5cm, completely penetrating the skull would have otherwise resulted in extensive parenchymal damage. Literature suggests that no two people have an identical frontal sinus. In our patient the size the frontal sinus has served the purpose of protection against PBI and has resulted in minimal parenchymal injury (of only about 1cm).

Provision of a local anaesthetic minor procedures service by surgical advanced clinical practitioners: 5-year study

BACKGROUND

Surgical advanced clinical practitioners (SACPs) form part of the extended surgical workforce drawn from a variety of allied healthcare backgrounds. The primary aim of this study was to determine whether there was a financial benefit in having minor surgical procedures undertaken by dedicated SACPs compared with operating lists assigned to consultant surgeons.

METHODS

This was a retrospective cohort study including all patients who had minor 'lumps and bumps' procedures undertaken between April 2014 and August 2019 at East Lancashire Hospitals NHS Trust under local anaesthetic by the general surgery team. Clinical patient information, including lesion type, was collected along with operating room staffing levels and duration of operation. The cost of the procedure was calculated as operating time multiplied by cost of staff per minute according to local banding.

RESULTS

A total of 1399 patients had a lesion excised; 907 procedures were carried out by a doctor, and the rest independently by a SACP. The majority of lesions excised were lipomas and cysts. There was no difference in the median surgical time taken between SACPs and doctors (20 (i.q.r. 14-28) min). Minor procedures carried out on consultant surgeon lists cost 62.3 per cent (€25.33) more on average than those on SACP lists (median €65.96 versus 40.63 respectively; P < 0.001).

CONCLUSION

A dedicated and independent SACP 'lumps and bumps' list was financially beneficial. Operating times were similar to those of doctors. These lists safely free trainee and consultant surgeons to undertake more complex work.

Limited utility of plasma elafin as a biomarker for skin graft-versus-host disease following allogeneic stem cell transplantation

BACKGROUND

Acute cutaneous graft-versus-host disease (acGVHD) following haematopoietic stem cell transplant (HSCT) is common but difficult to distinguish from other causes of rash. Plasma elafin has been proposed as a diagnostic and prognostic biomarker of skin GVHD.

AIM

To evaluate the role of plasma elafin as a biomarker in acGVHD in an Indian population.

METHODS

Plasma elafin was evaluated in a prospective study of HSCT recipients, conducted over 2 years, taking measurements at baseline and at onset of skin rash after HSCT. Patients were categorized into those with GVHD rash, those with non-GVHD rash and those with no rash and the three groups were compared.

RESULTS

Two hundred and sixty-one patients with a median age of 16 years (range 1-61 years) and a male predominance (175 : 86 M/F) underwent HSCT during the study period: 56 patients in the GVHD group, 49 in the non-GVHD group and 156 in the no-rash group. The median baseline elafin was similar in all three groups. At the onset of rash, median elafin level was similar between GVHD and non-GVHD rash (34 549 vs. 32 077 pg/mL; P = 0.58) and between GVHD and no rash (34 549 vs. 26 197 pg/mL; P = 0.08). A rise in elafin from baseline was significantly different between GVHD and no rash (P < 0.001) but not between GVHD and non-GVHD rash (P = 0.44).

CONCLUSION

The utility of plasma elafin as a biomarker of skin GVHD is very limited. Plasma elafin, although elevated in cutaneous GVHD, is not helpful in distinguishing between GVHD rash and other causes of rash following HSCT.

Perinatal loss and parental loneliness: Narratives of late termination of pregnancy

Advances in perinatal medicine, present increasing numbers of women with difficult decisions about their pregnancy. We explored the views of 5 parents and 5 perinatal healthcare professionals regarding late termination of pregnancy following the principles of qualitative content analysis. Parents deciding on whether to (dis)continue pregnancy needed more time and decisional support. Decentralized care and lacking continuity between caregivers led to negative experiences. No standardized bereavement services were offered after leaving the hospital. Integrating principles of perinatal palliative care to care might help to offer further decisional support and to overcome the fragmentation of care.

The accuracy of pre-operative (P)-POSSUM scoring and cardiopulmonary exercise testing in predicting morbidity and mortality after pancreatic and liver surgery: A systematic review

Background

Cardiopulmonary exercise-testing (CPET) and the (Portsmouth) Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity ((P)-POSSUM) are used as pre-operative risk stratification and audit tools in general surgery, however, both have been demonstrated to have limitations in major hepatopancreatobiliary (HPB) surgery.

Materials and methods

The aim of this review is to determine if CPET and (P)-POSSUM scoring systems accurately predict morbidity and mortality. Eligible articles were identified with an electronic database search. Analysis according to surgery type and tool used was performed.

Results

Twenty-five studies were included in the final review. POSSUM predicted morbidity demonstrated weighted O/E ratios of 0.75(95%CI0.57–0.97) in hepatic surgery and 0.85(95%CI0.8–0.9) in pancreatic surgery. P-POSSUM predicted mortality in pancreatic surgery demonstrated an O/E ratio of 0.75(95%CI0.27–2.13) and 0.94(95%CI0.57–1.55) in hepatic surgery. In both pancreatic and hepatic surgery an anaerobic threshold(AT) of between 9 0.5–11.5 ml/kg/min was predictive of post-operative complications, and in pancreatic surgery ventilatory equivalence of carbon dioxide(˙VE/˙VCO2) was predictive of 30-day mortality.

Conclusion

POSSUM demonstrates an overall lack of predictive fit for morbidity, whilst CPET variables provide some predictive power for post-operative outcomes. Development of a new HPB specific risk prediction tool would be beneficial; the combination of parameters from POSSUM and CPET, alongside HPB specific markers could overcome current limitations.

•

Current pre-operative scoring for pancreatic and liver surgery is inaccurate.

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In pancreatic and liver surgery anaerobic threshold scores were predictive of complications.

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In pancreatic surgery ventilatory equivalence of carbon dioxide was predictive of mortality.

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P-POSSUM is inaccurate for predicting mortality and morbidity in pancreatic surgery.

Intraductal Papillary Adenocarcinoma Of The Bile Duct With Associated Invasive Neuroendocrine Component: Case Report

Casestudy

Intraductal papillary neoplasm of the bile duct (IPNB) is a variant of bile duct carcinoma that is characterized by intraductal growth and better outcomes compared with common cholangiocarcinoma. IPNBs are mainly found in patients from Far Eastern countries, where hepatolithiasis and clonorchiasis are endemic.

Approximately 40%-80% of IPNBs are associated with invasive carcinoma. The invasive carcinomas are most often tubular or mucinous type. Invasive neuroendocrine component has not been previously described.

We present a case of 69 year-old African American male who presented with worsening abdominal pain and jaundice over few months. Computed tomography showed 4 cm mass near the porta hepatis with massive ductal dilatation. A fine needle aspiration of the mass was performed and a diagnosis of adenocarcinoma was made. Subsequently, the patient underwent Right Trisegmentectomy.

Conclusion

Histologic sections revealed intraductal papillary neoplasm in the bile duct lumina. The papillae were lined by columnar epithelial cells with delicate fibrovascular cores. The tumor cell nuclei were slightly elongated, hyperchromatic and basally located without significant multilayering. The cytoplasm was eosinophilic with occasional intestinal differentiation. Frank invasion of the stalk and underlying periductular tissues was identified. Interestingly; the invasive component had different cytological features than the intraductal component, it was composed of small to medium sized cells with granular cytoplasm. The nuclei were uniform and round with “salt and pepper” chromatin. The invasive component stained positively for the neuroendocrine markers (Synaptophysin, Chromogranin and CD56), whereas the intraductal component stained positively for CK7, CK20 and CDX2 and negative for neuroendocrine markers.

Three years later, a recurrent tumor was found in the left lobe on imaging. Biopsy of the lesion showed metastatic neuroendocrine carcinoma. The intraductal papillary neoplasm with invasive neuroendocrine component is very unusual tumor, we think more studies are warranted to best evaluate the treatment options and the prognosis of such neoplasms.

Adjuvant breast radiotherapy, endocrine therapy, or both after breast conserving surgery in older women with low-risk breast cancer: Results from a population-based study

BACKGROUND AND PURPOSE

The relative benefit of adjuvant radiotherapy (RT) alone in older women with low-risk early breast cancer (EBC) remains unclear. It is hypothesized that adjuvant RT-alone can improve outcomes of older patients with low-risk EBC, similar to endocrine therapy (ET) alone or combination of RT + ET.

METHODS

In this population based study, we identified all women aged ≥70 with T1-2, N0, ER+ve, Her-2/neu-ve EBC treated with breast conserving surgery (BCS), followed by adjuvant treatments (RT-alone, ET-alone, or RT + ET combination) from 2005 to 2015. Primary outcome measures were recurrence-free survival (RFS), overall survival (OS), and breast cancer specific survival (BCSS). Treatment details were collected and Charlson Comorbidity Index (CCI) was calculated.

RESULTS

A total of 1166 patients were identified. Median follow-up was 76.5 months. Adjuvant treatments: BCS only 130 (11%), RT 378 (32.5%), ET 161 (14%), and RT + ET 497 (42.5%). Less than 60% of women completed 5-years of ET. Compared to BCS alone, RT resulted in significant improvement in RFS (HR = 0.174; p < 0.001), similar to ET (HR = 0.414; p = 0.007) and RT + ET (HR = 0.236; p < 0.001). Determinants of OS were age, tumor grade, comorbidities, and adjuvant therapy. Increased comorbidity scores (0 vs. 1; 0 vs. ≥2) were associated with reduced OS (HR = 1.40; p = 0.013 and HR = 1.98; p < 0.001), without impact on RFS or BCSS.

CONCLUSIONS

Adjuvant RT-alone is a reasonable alternative to ET or RT + ET for older women with biologically favorable EBC. No difference in RFS or BCSS was noted between RT, ET, and RT + ET. Comorbidity was independently associated with reduced overall survival.

Characterization of a novel enzyme from Photobacterium phosphoreum with histidine decarboxylase activity

Histamine or scombrotoxin fish poisoning is caused by ingestion of bacterially produced histamine in fish. Histamine-producing bacteria generally contain the histidine decarboxylase gene (hdc). However, some strains of Photobacterium phosphoreum are known to produce significant levels of histamine, although the hdc gene in these strains has not been recognized. The objective of this study was to investigate a previously unidentified mechanism of histamine production by P. phosphoreum. We identified a protein with histidine decarboxylase (HDC) activity comparable to activity of the pyridoxal-5-phosphate (PLP) dependent HDC from P. kishitanii and M. morganii. The newly identified protein (HDC2) in P. phosphoreum and P. kishitanii strains, was approximately 2× longer than the HDC protein from other Gram-negative bacteria and had 12% similarity to previously identified HDCs. In addition, the hdc2 gene cluster in P. phosphoreum was identical to the hdc gene cluster in P. kishitanii. HDC2 had optimal activity at 20-35 °C, at pH 4, and was not affected by 0-8% NaCl concentrations. Compared to the hdc gene from P. kishitanii, expression of the hdc2 gene was constitutive and not affected by pH or excess histidine. This newly identified protein explains possible mechanisms of histamine production in P. phosphoreum. Characterization of this protein will help in designing control measures to prevent or reduce histamine production in fish.

Abstract B40: High circulating CCL5 is associated with poor prognosis in locally advanced pancreatic cancer (LAPC): Biomarker analysis from the randomized phase II SCALOP trial

Background: SCALOP recruited 114 patients with LAPC. Induction chemotherapy consisted of 3 cycles of gemcitabine and capecitabine (GEMCAP). Patients with nonprogression (n=74) were randomized to GEM or CAP based CRT (50.4Gy/28 fractions). Blood samples collected at baseline were analyzed for 35 angiogenic and immune biomarkers reported to be of prognostic/predictive value in pancreatic cancer.

Methods: IGF-1, TGF-b1, and b-NGF were analyzed using R & D DuoSet ELISA systems and the signal detected using a POLARstar Omega plate reader. The remaining biomarkers were assessed using R & D multiplexed magnetic Luminex assays and measured using a Luminex Magpix. Assays were performed in triplicate.

Statistical Analysis: Univariate Cox proportional hazard models were used as continuous variable to determine the association with overall survival (OS). Multiple comparisons were adjusted using the False Discovery Rate (FDR). Those found to be significant at the q value &lt;0.2 were then further investigated for independence from existing clinical characteristics (i.e., CA19-9, WHO PS and age). Of those found to be independent, optimal thresholds delineating low to high values were found using the R “survivalROC” package based on time-dependent ROC curves from censored survival data and their corresponding area under the curve (AUC). The dichotomized biomarkers, split at the optimal threshold, were then associated with OS using univariate and multivariable Cox proportional hazard models.

Results: Biomarker data were available on 63/74 patients. 57% (36/63) were male, 56% (35/63) were age &lt;65, 59% (37/63) had WHO PS 0 compared to 1, 51% (32/63) received gemcitabine, median CA19.9 was 233IU/L (IQR 75,801) and median tumor diameter was 3.8cm (IQR 3, 4.8). Of the 35 biomarkers tested, only CCL5, IL3, and IFN had significant associations with OS. CCL5 and IL3 were then found to be independent of existing clinical characteristics and were taken forward, where their optimal thresholds were found to be 1.27 micg/ml (sensitivity 64%; specificity 100%) and 57.75 pg/ml (sensitivity 83%; specificity 100%), respectively. CCL5, but not IL3, was found to be significantly associated with OS once dichotomized at its optimal threshold, with a median OS of 18.5 (95% CI: 11.76-21.32) vs. 11.3 (9.86-15.51) months, HR 1.37 (95% CI:1.04-3.65; p=0.037) in the Cox multivariable model. Moreover, biomarker signatures incorporating both CCL5 and IL3 (continuous variable) with age, PS and CA19.9 were prognostic: CCL5 signature:19.2 vs. 10.8 mo (HR 2.79, p=0.001) IL3 signature: 18.5 vs. 11.2 mo (HR 2.35, p=0.006) CCL5/IL3 signature: 18.7 vs. 11.2 mo, (HR 2.25, p=0.11).

Conclusion: High circulating CCL5 has a significantly worse prognosis. This is consistent with preclinical literature that demonstrates the role of CCL5 in tumor invasion/metastasis and induction of an immunosuppressive microenvironment through Treg infiltration. We are currently conducting in vivo experiments involving CCR5 antagonists and immunotherapy in orthotopic mouse models.

Citation Format: Frances Willenbrock, Catrin Cox, Charlotte Wilhelm-Benartzi, Aswin Abraham, Robert Owens, Ahmad Sabbagh, Chris Hurt, Tim Maughan, Eric O'Neill, Somnath Mukherjee. High circulating CCL5 is associated with poor prognosis in locally advanced pancreatic cancer (LAPC): Biomarker analysis from the randomized phase II SCALOP trial [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B40.

Abstract PR02: Loss of TET2 activity results in epigenetic instability and drives PDAC molecular subtypes

Background: mRNA datasets have defined two molecular subtypes of pancreatic ductal adenocarcinoma (PDAC), classical and squamous, with distinct clinical characteristics and raising the possibility of subtype specific therapies (Collisson et al., 2019). The aggressive squamous subtype is characterized by poorer patient survival and loss of endodermal differentiation markers GATA6 and PDX1, but neither PDAC subtypes nor metastasis can be explained by genetic mutations alone (Reiter et al., 2018). Conversely, widespread epigenetic reprogramming is associated with progression to more aggressive phenotypes (McDonald et al., 2017), suggesting that aggressive molecular subtype is likely to be epigenetically driven. The role of DNA 5’methylcytosine (5’mc) in PDAC has been previously unclear due to an inability to distinguish this mark from the reciprocal activation mark DNA 5’hydroxymethylcytosine (5’hmC), mediated by Ten-eleven-translocation (TET) enzymes. Moreover, 5’hmc is dynamically regulated during pancreatic differentiation, but a role during PDAC initiation or progression has not been previously addressed.

Methods: PDAC patients who underwent surgical resection at the Churchill Hospital, Oxford (n=146) had FFPE tumor tissue mutation comprehensively profiled by illumina hotspot array (300X), mRNA microarray, and the first epigenetic separation of 5’mc and 5’hmc on FFPE via oxidative bisulphite sequencing (oxBS) and illumina EPIC arrays. iCluster was used to highlight epigenetic PDAC subtypes and compare to existing TCGA datasets. Orthotopic models were employed to test whether the Squamous subtype is defined by 5’hmc loss and if this can be converted to the classical subtype in vivo.

Results: Compared to healthy tissue, PDAC tumors demonstrate loss of 5’hmC at genes critical for pancreatic development and associated with PDAC progression, including MAPK signaling and TP53 targets. 5’hmC was preferentially lost in aggressive molecular subtypes (squamous) compared to the classical subtypes and was associated with SMAD4 mutations and reduced TET2. Overexpression of TET2 in squamous tumor cells restored 5’hmc and the expression of classical associated genes (e.g., GATA6 and PDX1), suggesting that 5’hmC is a master epigenetic regulator of PDAC molecular subtypes. Notably, we find TET2 stability is regulated by glucose levels, implying the widespread hypoglycemia seen in PDAC patients may contribute to progression of aggressive subtypes through loss of 5’hmC. Concomitantly, as metformin and vitamin C independently enhance endogenous TET2 activity, we find that this combination acts synergistically on squamous tumors to increase 5’hmC and expression of a classical-subtype phenotype, suggesting subtype switching is achievable in vitro and in vivo.

Conclusion: These results identify 5’hmC as a regulator of molecular subtype that can be targeted in vivo using well-tolerated drugs.

This abstract is also being presented as Poster A39.

Citation Format: Michael Eyres, Simone Lanfredini, Frances Willenbrock, Asmita Thapa, Andrew Blake, Adam Burns, Ahmad Sabbagh, Aswin Abraham, Timothy Maughan, Zahir Soonawalla, Anna Schuh, Somnath Mukhergee, Eric O'Neill. Loss of TET2 activity results in epigenetic instability and drives PDAC molecular subtypes [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr PR02.

Treating complexity in the older adult - the role of the geriatric giants

As people age, they accumulate medical conditions. Geriatric giants comprise a group of conditions that lead to significant mortality and morbidity and contribute to the complexity in treating geriatric patients. They are common and rarely occur in isolation. The 5 Is of geriatric giants are: iatrogenesis, immobility, instability, incontinence and impaired cognition. Consequences for the patient and their caregivers include loss of functional independence, institutionalisation and caregiver burnout. Primary care practitioners are often the first port of call for geriatric patients in South Africa and by asking a few key questions and performing a thorough examination; these conditions can be recognised early. Whilst there are often limitations to cure, the main aim is to maintain the older adult’s functional independence as much as possible, and by following an organised management approach to each of these conditions, the quality of life of patients can be improved.

Mesenchymal stem cell-derived extracellular vesicles for the treatment of acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a serious and potentially fatal acute inflammatory lung condition which currently has no specific treatments targeting its pathophysiology. However, mesenchymal stem cells have been shown to have very promising therapeutic potential, and recently, it has been established that their effect is largely due to the transfer of extracellular vesicles (EVs). EVs have been shown to transfer a variety of substances such as mRNA, miRNA, and even organelles such as mitochondria in order to ameliorate ARDS in preclinical models. In addition, the fact that they have been proven to have the same effect as their parent cells combined with their numerous advantages over whole cell administration means that they are a promising candidate for clinical application that merits further research.

Burning Feet, Dilated Heart and Failed Kidneys

Fabry's disease, X-linked lysosomal storage disease, results from deficient activity of alpha galactosidaseA (α-GalA). Renal manifestation usually begins at third decade of life. We report a 16 year male with initial presentation with end stage renal disease (ESRD) and the diagnosis confirmed by presence of myeloid bodies on electron microscopy of kidney biopsy and low serum α-GalA level.

A novel vaccine platform using glucan particles for induction of protective responses against Francisella tularensis and other pathogens

Vaccines are considered the bedrock of preventive medicine. However, for many pathogens, it has been challenging to develop vaccines that stimulate protective, long-lasting immunity. We have developed a novel approach using β-1,3-D-glucans (BGs), natural polysaccharides abundantly present in fungal cell walls, as a biomaterial platform for vaccine delivery. BGs simultaneously provide for receptor-targeted antigen delivery to specialized antigen-presenting cells together with adjuvant properties to stimulate antigen-specific and trained non-specific immune responses. This review focuses on various approaches of using BG particles (GPs) to develop bacterial and fungal vaccine candidates. A special case history for the development of an effective GP tularaemia vaccine candidate is highlighted.

Chronic stress, depression and personality type in patients with myasthenia gravis

BACKGROUND AND PURPOSE

Stress is a known risk factor for the onset and modulation of disease activity in autoimmune disorders. The aim of this cross-sectional study was to determine any associations between myasthenia gravis (MG) severity and chronic stress, depression and personality type.

METHODS

In all, 179 consecutive adult patients with confirmed MG attending the Neuromuscular Clinic between March 2017 and December 2017 were included. At baseline, patients were assessed clinically and they completed self-administered scales for disease severity, perceived stress, depression and personality type.

RESULTS

Higher disease severity [Myasthenia Gravis Impairment Index (MGII)] showed a moderate correlation with depression score (Beck's Depression Inventory, Second Edition, r = 0.52, P < 0.001) and a lower correlation with chronic stress (Trier Inventory for Assessment of Chronic Stress, r = 0.28, P = 0.001). Chronic stress scores were different according to personality types (anova, P = 0.02). The linear regression model with MGII score as the dependent variable showed R² = 0.34, likelihood ratio chi-squared 74.55, with P < 0.0001. The only variables that predicted disease severity were depression scores (P < 0.0001) and female sex (P = 0.003).

CONCLUSIONS

A significant association of MG severity with depression and chronic stress was found, as well as with female gender. These findings should raise awareness that the long-term management of MG should address depression and potential stress and consider behavioural management to prevent stress-related immune imbalance.