Outcomes of subsequent abdominal operations after an initial ventral hernia repair

INTRODUCTION

Nearly 20% of ventral hernia repair (VHR) patients require a subsequent abdominal operation (SAO), and mesh position may impact the complexity and outcome of the SAO.

METHODS

Retrospective review of VHR with mesh from 2006 to 2020 from an internal database and the ACHQC. Primary outcomes measured incidence, complexity, and complications of SAO relative to mesh position.

RESULTS

SAO was required in 433 of 2539 (17.1%) patients, totaling 671 operations; 197/893 (22.1%) with intraperitoneal mesh (IPM) and 236/1646 (14.3%) with extraperitoneal mesh (EPM; p ​< ​0.001). SAO was directly related to VHR in 180 (232 total SAOs) and unrelated in 253 (439 total SAOs). There were no significant differences in complications after SAO between IPM and EPM, nor any difference in adhesion complexity.

CONCLUSION

Incidence of SAO is higher with IPM, but surgical outcomes are similar. Due to the risk of secondary mesh infection with IPM, significantly more of these were removed at the time of SAO.

Outcomes after initial refusal of curative treatment in patients with Hodgkin’s lymphoma in British Columbia

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Background: Classical Hodgkin lymphoma (cHL) is considered a highly curable cancer. With standard combination chemotherapy regimens, long-term survival exceeds 95% for limited-stage and 85% for advanced-stage patients. Despite these excellent outcomes some patients delay or decline conventional treatment for cHL. We retrospectively assessed the impact of initial treatment refusal on outcomes of patients with cHL in British Columbia (BC). Methods: Using the BC Cancer Lymphoid Cancer Database, we identified all patients aged 18-70 diagnosed between 1st Jan 1999- 31st Dec 2020 that had documented treatment refusal at initial presentation (‘refusers’ defined as not receiving or delaying treatment > 16 weeks). We identified a control cohort (min. 3 controls/refuser) treated within 8 weeks of diagnosis, matched for age, stage, diagnosis date within 3 years, and blinded for outcome. All patients had centrally reviewed biopsies and were treated with ABVD or ABVD-like regimens +/- radiotherapy if appropriate. Patient and disease characteristics at baseline and at time of treatment were analyzed with Chi-squared test and one-way ANOVA test. The Kaplan-Meier method was used to assess progression-free survival (PFS) and overall survival (OS), and statistical significance between groups was determined using the log-rank test. Results: We identified a cohort of 15 patients who initially refused treatment and 47 matched controls. The control cohort was well-matched, with no statistically significant differences in baseline characteristics (age, sex, Ann Arbor stage, B symptoms, International Prognostic Score (IPS) score, ECOG PS, and disease bulk) between groups. The most common reason for initial treatment refusal was to pursue alternative therapy (73%). 13 of 15 refusers eventually accepted treatment (mean time to treatment 76 weeks [range 26-214] vs. 5 weeks [range 1-8] for controls, p < 0.001). At time of treatment, the proportion of refusers with advanced-stage disease increased from 20% to 62% (p = 0.03) and had an associated alteration of treatment plan, and 62% of patients developed higher risk disease with increased IPS score (p = 0.02). At median follow-up of 5 years (0.4-21 years) for all living patients, estimated 5-year PFS was 65% vs 84%, and 5-year OS was 93% vs 98% for refusers and controls respectively. With extended follow up, 13% of refusers (1 late death at 8 years) compared to only 4% of controls died of cHL specifically. Conclusions: This study highlights the impact of treatment refusal in this highly curable malignancy. Initial refusal of treatment is associated with progression of stage, worsening prognostic score, escalation to more prolonged treatment than required at diagnosis, and increased risk of death from cHL. This analysis may help to provide guidance to counselling physicians, as well as inform patients who may be considering alternatives to standard of care for cHL.

O29: PREDICTING RESPONSE TO NEOADJUVANT THERAPY IN OESOPHAGEAL ADENOCARCINOMA PRE-TREATMENT BIOPSIES

Aims

We currently cannot predict which patients with locally advanced oesophageal adenocarcinoma will be amongst the 15-20% to gain a clinically important response to neoadjuvant therapy (NAT). This pilot study aimed to identify differentially expressed genes from oesophageal adenocarcinoma pre-treatment biopsies between responders and non-responders to NAT and develop methodology for predicting response.

Method

Response to NAT was assessed pathologically using Tumour Regression Grading (TRG). Pre-treatment formalin-fixed paraffin embedded samples were analysed with two nuclease protection assays (EdgeSeq, HTG = Oncology Biomarker Panel (OBP) and Precision Immuno-Oncology Panel (PIP)). Sequencing was performed on the NextSeq500 (Illumina).

Result

Whilst there was no difference in pre-treatment characteristics, responders (TRG1-2, n=26) had significantly better post-treatment pathology and overall survival than non-responders (TRG4-5, n=30). Genes up-regulated in responders were involved in regulating cell cycling, whereas genes up-regulated in non-responders were involved in cytokine signalling and the immune response. Neuronal artificial network models could predict response to NAT with overall accuracy of 73% and 68% for the OBP and PIP, respectively, which is promising considering the small sample size. As no model will be 100% accurate, we developed a model that could take patient's views into consideration with an adjustable probability threshold for classification.

Conclusion

This pilot study informs a biologically sound hypothesis for the basis of response to NAT and suggests prediction from pre-treatment biopsies may be possible using EdgeSeq. We now aim to validate these results in a larger study to inform a bespoke classifier of response to enable delivery of precision therapy.

Take-home message

In oesophageal adenocarcinoma, responders and non-responders to neoadjuvant therapy have different expression profiles. Through using EdgeSeq in larger studies, we may be able to predict which patients will respond to treatment, allowing for delivery of precision therapy.

Abstract P4-04-03: Obesity-induced EMT in luminal A breast cancer cells

Introduction: Obesity is associated with a worse prognosis in breast cancer, including the less aggressive ER+ luminal A subtype, but the mechanisms by which it promotes disease progression are unclear, making treatment difficult. Obese breast cancer patients have a higher risk of a more aggressive disease compared to lean patients, which is associated with treatment resistance and metastasis. The mechanisms promoting obesity-driven metastasis are not understood, but several studies have indicated that obesity is associated with a “stem-like” phenotype. A “reprogramming” occurs, transforming stationary, epithelial cells to motile, malignant cells that exhibit a more aggressive phenotype than their stromal counterparts. Our data suggest that in vitro exposure of luminal A breast cancer cells to obese conditions may induce an epithelial to mesenchymal transition (EMT), which is characterized by a more stem-like phenotype, resistance to treatment (chemo, hormone and radiation), as well as greater metastatic potential. This has let us to hypothesize that one critical mechanism by which obesity promotes a more aggressive disease is through inducing an EMT reprogramming, resulting in a more stem-like phenotype.

Methods and Results: Both in vitro and translational approaches will be done to determine if obesity induces epigenetic reprograming associated with a more stem-like phenotype. MCF-7 ER+ breast cancer cells exposed to 2% sera from obese (BMI ≥ 30) postmenopausal women demonstrated a significant increase in expression of both SNAIL1 and TWIST transcription factors (9-fold and 4-fold, respectively) which are implicated in EMT and potentially stem-cell programming, compared to those exposed to sera from lean women. Current studies are underway to determine if this is observed in other ER+ luminal A cell lines, including T47D, and whether induced changes in these transcription factors results in changes in signaling pathways associated with EMT, including TGFβ, which can activate the PI3K–AKT, ERK MAPK, p38 MAPK and JNK pathways and WNT signaling, which promotes EMT by stabilizing β-catenin. Additionally, the luminal A cell lines will be assessed for changes in other factors known to modulate breast cancer cell programming, including KLF4, OCT4, SOX2, and NANOG.

Conclusions: Our earlier studies have demonstrated that obesity promotes a more aggressive disease even in luminal A disease. The mechanisms for this remain unclear. Our exciting preliminary findings suggest that obesity might induce a reprogramming of the luminal A well-differentiated cell to a more stem-like phenotype. Our results will lay an important foundation for understanding how obesity modulates breast cancer disease progression, whether this programming may provide therapeutic target to improve response and overall survival in the obese patient.

Citation Format: Hayden A, Quach D, Galvan G, Patodia R, Brenner A, deGraffenried L. Obesity-induced EMT in luminal A breast cancer cells [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-04-03.

The impact of drug use patterns on mortality among polysubstance users in a Canadian setting: a prospective cohort study

Background

Illicit drug use is a well-established risk factor for morbidity and mortality. However, few studies have examined the impact of different drug use patterns on mortality among polysubstance using populations. This study aimed to identify drug-specific patterns of mortality among a cohort of polysubstance using persons who inject drugs (PWIDs).

Methods

PWIDs in Vancouver, Canada were prospectively followed between May 1996 and December 2011. Participants were linked to the provincial vital statistics database to ascertain mortality rates and causes of death. We used multivariate Cox proportional hazards regression to investigate the relationships between drug use patterns (daily alcohol use, heroin injection and non-injection use, cocaine injection, amphetamine injection and non-injection use, crack smoking and speedball injecting) and time to all-cause mortality.

Results

2330 individuals were followed for a median of 61 months (inter-quartile range: 33 – 112). In total, 466 (19.1%) individuals died for an incidence density of 3.1 (95% confidence interval [CI]: 2.8 – 3.4) deaths per 100 person-years. In multivariate analyses, after adjusting for HIV infection and other potential confounders, only daily cocaine injection remained independently associated with all-cause mortality (adjusted hazard ratio [AHR] = 1.36, 95% CI: 1.06 – 1.76).

Conclusions

Although heroin injecting is traditionally viewed as carrying the highest risk of mortality, in this setting, only daily cocaine injecting was associated with all-cause mortality. These findings highlight the urgent need to identify novel treatments and harm reduction strategies for cocaine injectors.

Investigating the Nrf2 transcription factor as a regulator of cisplatin resistance in urothelial carcinoma (UC) cells

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Background: Nrf2 controls expression of multiple target genes, each containing an antioxidant response element (ARE). These targets mediate cellular protection through antioxidant response, cellular detoxification (including glutathione conjugation), and altered drug uptake/efflux. Some targets (e.g., metallothionein, glutathione reductase) are associated with UC characteristics, outcomes, and chemotherapy resistance. Nrf2 regulation is partially understood and includes negative regulation by Keap1 and phosphorylation. De-novo or acquired cisplatin resistance is a problem in UC. We hypothesised that it might be mediated by Nrf2.

Methods: Nrf2 expression was assessed in UC clinical samples by immunohistochemistry. We then utilised a panel of UC cell lines, including a cisplatin resistant RT112 sub-line (RT112CP), to test Nrf2 axis expression and activation correlated to cisplatin sensitivity/resistance. Effects of AKT or HER2 kinase activity on Nrf2 activation were tested by chemical inhibition.

Results: In UC clinical samples we detected Nrf2 over-expression in 64% of cancers compared to surrounding normal tissue. Varied Nrf2 expression levels were also detected in different UC cell lines whereas Keap1 demonstrated an inverse profile of both RNA and protein expression. Nrf2 expression was 4 fold greater in RT112CP cells which exhibited comparative cisplatin resistance (10 fold greater IC50 in proliferation assays) compared to parental cells. Nrf2 over expression was functional in this model system as indicated by increased activity in ARE luciferase reporter assays, raised expression of Nrf2 transcriptional targets (metallothionein, glutathione reductase) and glutathione levels. Furthermore, depletion of Nrf2 in RT112CP cells by siRNA or transfection of a dominant negative Nrf2 construct partially restored cisplatin sensitivity. Finally chemical inhibition of AKT or HER2 reduced Nrf2 activation in ARE reporter assays.

Conclusions: Nrf2 is overexpressed in a subset of UC. In cell line models it is functionally activated and contributes to cisplatin resistance, which is reversible. This might be amenable to detection and therapeutic reversal in the clinic.

No significant financial relationships to disclose.

New approach to radiation burn treatment by dosimetry-guided surgery combined with autologous mesenchymal stem cell therapy

The therapeutic management of severe radiation burns remains a challenging issue. Conventional surgical treatment (excision and skin autograft or rotation flap) often fails to prevent unpredictable and uncontrolled extension of the radiation necrotic process. We report here an innovative therapeutic strategy applied to the victim of a radiation accident (December 15, 2005) with an iridium gammagraphy radioactive source (192Ir, 3.3 TBq). The approach combined numerical dosimetry-guided surgery with cellular therapy using mesenchymal stem cells. A very severe buttock radiation burn (2000 Gy at the center of the skin surface lesion) of a 27-year-old Chilean victim was widely excised (10 cm in diameter) using a physical and anatomical dose reconstruction in order to better define the limit of the surgical excision in apparently healthy tissues. A secondary extension of the radiation necrosis led to a new excision of fibronecrotic tissues associated with a local cellular therapy using autologous expanded mesenchymal stem cells as a source of trophic factors to promote tissue regeneration. Bone marrow-derived mesenchymal stem cells were expanded according to a clinical-grade technique using closed culture devices and serum-free medium enriched in human platelet lysate. The clinical evolution (radiation pain and healing progression) was favorable and no recurrence of radiation inflammatory waves was observed during the 11 month patient's follow-up. This novel multidisciplinary therapeutic approach combining physical techniques, surgical procedures and cellular therapy with adult stem cells may be of clinical relevance for improving the medical management of severe localized irradiations. It may open new prospects in the field of radiotherapy complications.

Both hepatic and extrahepatic ABCA1 have discrete and essential functions in the maintenance of plasma high-density lipoprotein cholesterol levels in vivo

BACKGROUND

Extrahepatic tissues have long been considered critical contributors of cholesterol to nascent HDL particles in the reverse cholesterol transport pathway, in which ABCA1 plays the crucial role. Recent studies, however, including both overexpression and deletion of ABCA1 selectively in the liver, have highlighted the primary role of the liver in the maintenance of HDL levels in vivo.

METHODS AND RESULTS

The availability of mice with complete deletion of ABCA1 (total knockout [TKO]) and with liver-specific deletion of ABCA1 (LSKO) has enabled us to dissect the discrete roles of hepatic relative to extrahepatic ABCA1 in HDL biogenesis. Delivery of adenoviral ABCA1 resulted in selective expression of physiological levels of ABCA1 in the livers of both LSKO and TKO mice, resulting in increased HDL cholesterol (HDL-C). Expression of ABCA1 in the liver of LSKO mice resulted in plasma HDL-C levels that were similar to those in wild-type mice and significantly above those seen in similarly treated TKO mice. HDL particles from ABCA1-expressing LSKO mice were larger and contained significantly increased cholesterol compared with TKO mice. Infusion of human apolipoprotein A-I/phospholipid reconstituted HDL particles normalized plasma HDL-C levels in LSKO mice but had no effect on HDL-C levels in TKO mice.

CONCLUSIONS

Although hepatic ABCA1 appears crucial for phospholipid transport, extrahepatic tissues play an important role in cholesterol transfer to nascent HDL particles. These data highlight the discrete and specific roles of both liver and extrahepatic ABCA1 in HDL biogenesis in vivo and indicate that ABCA1 shows lipid cargo selectivity depending on its site of expression.

A phase II study of gemcitabine plus carboplatin in platinum-sensitive, recurrent ovarian carcinoma

OBJECTIVES

Gemcitabine and carboplatin each have demonstrated effectiveness without increased neurotoxicity in pretreated patients with ovarian cancer. We evaluated the efficacy and safety of gemcitabine plus carboplatin in patients with recurrent ovarian cancer in a multicenter phase II study.

METHODS

Women with histologically proven measurable or evaluable epithelial ovarian cancer (any FIGO) who relapsed > or =6 months after discontinuation of first-line, platinum-containing therapy received gemcitabine 1000 mg/m(2) on days 1 and 8 and carboplatin AUC 4 on day 1 (after gemcitabine) every 21 days for up to six cycles.

RESULTS

Of the 40 enrolled/evaluable patients, 6 (15%) had complete response and 19 (47.5%) had partial response (PR), including one patient with PR in nonmeasurable disease (PRNM), for an overall response rate of 62.5% (95% CI, 45.8-77.3%). The median duration of response was 7.8 months (95% CI, 6.7-10.0), the median time to progressive disease was 9.6 months (95% CI, 8.5-11.0), and the median time to treatment failure was 9.3 months (95% CI, 8.2-10.4). The main grade 3/4 toxicities were neutropenia (78% of patients), leukopenia (30%), thrombocytopenia (18%), and anemia (15%); no grade 4 nonhematologic toxicities occurred, and grade 3 nonhematologic toxicities were mild.

CONCLUSIONS

The combination of gemcitabine and carboplatin is active and feasible in platinum-sensitive patients with recurrent ovarian cancer. This regimen is undergoing further evaluation in a large phase III trial.

Health-related quality-of-life parameters as independent prognostic factors in advanced or metastatic bladder cancer

PURPOSE

This retrospective analysis examined prognostic significance of health-related quality-of-life (HRQoL) parameters combined with baseline clinical factors on outcomes (overall survival, time to progressive disease, and time to treatment failure) in bladder cancer.

PATIENTS AND METHODS

Outcome and HRQoL (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30) data were collected prospectively in a phase III study assessing gemcitabine and cisplatin versus methotrexate, vinblastine, doxorubicin, and cisplatin in locally advanced or metastatic bladder cancer. Prespecified baseline clinical factors (performance status, tumor-node-metastasis staging, visceral metastases [VM], alkaline phosphatase [AP] level, number of metastatic sites, prior radiotherapy, disease measurability, sex, time from diagnosis, and sites of disease) and selected HRQoL parameters (global QoL; all functional scales; symptoms: pain, fatigue, insomnia, dyspnea, anorexia) were evaluated using Cox's proportional hazards model. Factors with individual prognostic value (P <.05) on outcomes in univariate models were assessed for joint prognostic value in a multivariate model. A final model was developed using a backward selection strategy.

RESULTS

Patients with baseline HRQoL were included (364 of 405, 90%). The final model predicted longer survival with low/normal AP levels, no VM, high physical functioning, low role functioning, and no anorexia. Positive prognostic factors for time to progressive disease were good performance status, low/normal AP levels, no VM, and minimal fatigue; for time to treatment failure, they were low/normal AP levels, minimal fatigue, and no anorexia. Global QoL was a significant predictor of outcome in univariate analyses but was not retained in the multivariate model.

CONCLUSION

HRQoL parameters are independent prognostic factors for outcome in advanced bladder cancer; their prognostic importance needs further evaluation.

Complications following re-exploration of the groin for recurrent varicose veins

BACKGROUND

Groin surgery for recurrent varicose veins can be technically difficult due to scarring from previous surgery. Access to the sapheno-femoral junction (SFJ) can be facilitated by approaching the veins indirectly (subfascially) by first exposing the common femoral artery. The aim of this paper was to document experience with both direct and indirect approaches to the SFJ for recurrent varicose veins.

METHOD

A retrospective analysis of all patients having groin surgery for recurrent varicose veins.

RESULTS

Of 128 legs having surgery, the approach to the SFJ was direct in 46%, indirect in 53% and unknown in one leg. Complications occurred after 40% of all procedures but were significantly more common following indirect surgery (57% versus 20%, P < 0.001), of which the most frequent were of a lymphatic nature (26% versus 5%, P < 0.001) or wound infection (16% versus 7%, P = 0.05).

CONCLUSION

Wound complications are common following groin surgery for recurrent varicose veins especially after an indirect approach to the SFJ.

Transmyocardial revascularization: a case study

Transmyocardial revascularization (TMR) is an investigational cardiovascular surgical procedure for patients with severe advanced coronary artery disease refractory to conventional treatment. The following case study traces one particular patient undergoing TMR from preoperative evaluation through a 6-month follow-up visit based on TMR research protocol.

Determination of trace-gas amounts in plumes by the use of orthogonal digital filtering of thermal-emission spectra

The thermal emission of gases in a plume can be measured by a Fourier-transform spectrometer that is located some distance from the plume. In order to measure quantitatively the amount of a particular gas of interest, in general a large spectrally structured background must be removed. Differencing techniques, in which a measured background spectrum is subtracted from a measured spectrum believed to contain a target, often do not remove background spectral features adequately. The inadequacy of two-spectrum differencing techniques is due to the spatial and the temporal variations in a scene. We present a method by which to reduce spatial and temporal spectral clutter to instrument random noise, allowing the measurement of gas amounts in an effluent plume. The method is applied to simulated data and field data to show its effectiveness.

Prognosis of chronic unexplained dyspepsia. A prospective study of potential predictor variables in patients with endoscopically diagnosed nonulcer dyspepsia

The aim of this study was to determine if there were predictors of the symptomatic course of patients with chronic unexplained (essential) dyspepsia. After endoscopic assessment, 111 patients with essential dyspepsia were followed up by telephone interview every second month. Data were gathered, for a mean of 17 mo per patient, on the number of days of upper abdominal pain (the response variable) each month. In the 6-mo period before entry to the study the following predetermined predictor variables were collected: demographic factors (age, sex, social grade), number of pain days in the 6 mo before diagnosis, environmental factors (analgesics, nonsalicylate nonsteroidal antiinflammatory drugs, alcohol, smoking, coffee, tea), length of dyspepsia history, and past history of peptic ulcer. Prospectively for each month of follow-up, the following additional variables were recorded: environmental factors, treatment, and development of gastroesophageal reflux symptoms. It was found that patients with more pain before diagnosis were significantly more likely to have pain over the follow-up, and the taking of medications for dyspepsia and development of gastroesophageal reflux were associated with more days of pain over the follow-up (all p less than 0.001). Demographic and environmental factors, length of dyspepsia history, and a past history of ulcer were of no significant predictive value. There was a decrease in pain over the follow-up period (p = 0.002), but this effect was limited to the first two periods after endoscopic diagnosis.

Randomized, double-blind, placebo-controlled crossover trial of cimetidine and pirenzepine in nonulcer dyspepsia

Nonulcer dyspepsia remains a difficult disorder to treat because it is a heterogeneous syndrome. Once patients with the irritable bowel syndrome, esophagitis, and other organic diseases are excluded, there remain patients with dyspepsia of unknown cause (termed "essential dyspepsia") and patients with dyspepsia plus symptoms of gastroesophageal reflux without esophagitis. The aim of this study was to determine whether cimetidine or pirenzepine is efficacious in relieving the symptoms of these latter subgroups. Sixty-two consecutive patients were studied who had chronic upper abdominal pain or nausea where endoscopy had shown no evidence of peptic ulceration, esophagitis, or malignancy; 47 had essential dyspepsia, and 15 had dyspepsia plus gastroesophageal reflux. They were initially randomized to either cimetidine or placebo, or pirenzepine or placebo. Patients continued each medication for 1 mo, and, after a washout period, crossed over when again symptomatic; 51 patients completed cimetidine and placebo, and 50 completed pirenzepine and placebo. The results showed that cimetidine was superior to placebo in decreasing the number of upper abdominal pain episodes weekly and the severity of pain, but the absolute improvement was small. Pirenzepine was not superior to placebo in decreasing symptoms.