A cost analysis of treating postoperative periprosthetic femoral fractures following hip replacement surgery in a UK tertiary referral centre

AIM

This study aims to evaluate costs associated with periprosthetic femoral fracture (PFF) treatment at a UK tertiary referral centre.

METHODS

This study included 128 consecutive PFFs admitted from 02/04/2014-19/05/2020. Financial data were provided by Patient Level Information and Costing Systems. Primary outcomes were median cost and margin. Secondary outcomes were length of stay, blood transfusion, critical care, 30-day readmission, 2-year local complication, 2-year systemic complication, 2-year reoperation and 30-day mortality rates. Statistical comparisons were made between treatment type. Statistical significance was set at p<0.05.

RESULTS

Across the cohort, median cost was £15,644.00 (IQR £11,031.00-£22,255.00) and median loss was £3757.50 (£599.20-£8296.20). The highest costs were ward stay (£3994.00, IQR £1,765.00-£7,013.00), theatre utilisation (£2962.00, IQR £0.00-£4,286.00) and overheads (£1705.10, IQR £896.70-£2432.20). Cost (£17,455.00 [IQR, £13,194.00-£23,308.00] versus £7697.00 [IQR £3871.00-£10,847.00], p<0.001) and loss (£4890.00 [IQR £1308.00-£10,009.00] versus £1882.00 [IQR £313.00-£3851.00], p = 0.02) were greater in the operative versus the nonoperative group. There was no difference in cost (£17,634.00 [IQR £12,965.00-£22,958.00] versus £17,399.00 [IQR £13,394.00-£23,404.00], p = 0.98) or loss (£5374.00 [IQR £1950.00-£10,143.00] versus £3860.00 [IQR -£95.50-£7601.00], p = 0.21) between the open reduction and internal fixation (ORIF) and revision groups. More patients required blood transfusion in the operative versus the nonoperative group (17 [17.9%] versus 0 [0.0%], p = 0.009). There was no difference in any clinical outcome between the ORIF and revision groups (p>0.05).

CONCLUSION

PFF treatment costs are high with inadequate reimbursement from NHS tariff. Work is needed to address this disparity and reduce hospital costs. Cost should not be used to decide between ORIF and revision surgery.

Incisional hernia following colorectal cancer surgery according to suture technique: Hughes Abdominal Repair Randomized Trial (HART)

BACKGROUND

Incisional hernias cause morbidity and may require further surgery. HART (Hughes Abdominal Repair Trial) assessed the effect of an alternative suture method on the incidence of incisional hernia following colorectal cancer surgery.

METHODS

A pragmatic multicentre single-blind RCT allocated patients undergoing midline incision for colorectal cancer to either Hughes closure (double far-near-near-far sutures of 1 nylon suture at 2-cm intervals along the fascia combined with conventional mass closure) or the surgeon's standard closure. The primary outcome was the incidence of incisional hernia at 1 year assessed by clinical examination. An intention-to-treat analysis was performed.

RESULTS

Between August 2014 and February 2018, 802 patients were randomized to either Hughes closure (401) or the standard mass closure group (401). At 1 year after surgery, 672 patients (83.7 per cent) were included in the primary outcome analysis; 50 of 339 patients (14.8 per cent) in the Hughes group and 57 of 333 (17.1 per cent) in the standard closure group had incisional hernia (OR 0.84, 95 per cent c.i. 0.55 to 1.27; P = 0.402). At 2 years, 78 patients (28.7 per cent) in the Hughes repair group and 84 (31.8 per cent) in the standard closure group had incisional hernia (OR 0.86, 0.59 to 1.25; P = 0.429). Adverse events were similar in the two groups, apart from the rate of surgical-site infection, which was higher in the Hughes group (13.2 versus 7.7 per cent; OR 1.82, 1.14 to 2.91; P = 0.011).

CONCLUSION

The incidence of incisional hernia after colorectal cancer surgery is high. There was no statistical difference in incidence between Hughes closure and mass closure at 1 or 2 years.

REGISTRATION NUMBER

ISRCTN25616490 (http://www.controlled-trials.com).

P19 A service evaluation to assess antimicrobial resistance in penicillin allergy

Background

Antibiotic consumption is one of the main drivers for antimicrobial resistance (AMR). To improve clinical outcomes and tackle AMR, we need to improve antibiotic usage in patients with penicillin allergy (PenA). Patients with PenA have been found to have higher antibiotic usage, often requiring repeated courses of antibiotics compared with those without PenA. Additionally, patients with PenA are more likely to receive broad spectrum antibiotics.

Objectives

To determine whether patients who have PenA are more likely to be colonized or infected with resistant bacteria.

Methods

Data were extracted from the pathology reporting system (Telepath) for blood culture specimens isolating Staphylococcus aureus and Streptococcus pneumoniae between 2017 and 2019 at Leeds Teaching Hospitals NHS Trust. Sputum samples from 2019 that isolated S. pneumoniae and Haemophilus influenzae were also analysed. These organisms/samples were chosen as these would indicate the presence of an infection where a penicillin would normally be used as first-line therapy. Where patients had multiple samples only the first sample obtained during the study period was included in the analysis. Standard descriptive statistics was used to summarize the data and characteristics were cross tabulated with penicillin allergy status.

Results

S. pneumoniae isolated from blood cultures: A total of 297 patients were included in the analysis, 33/297 (11.1%) had PenA, 50.8% were female and the median age was 60 years (IQR 37–75). Susceptibility results are summarized in Figure 1. Resistant isolates are comprised of isolates with resistant or intermediate susceptibility. S. aureus isolated from blood cultures: Analysis included 783 isolates from first patient encounters, 97/783 (12.4%) patients had PenA, 35.1% were female and the median age was 58 years (IQR 39–74.5). Susceptibility results are summarized in Figure 2. S. pneumoniae isolated from sputum: A total of 156 isolates were included in the final analysis: 29/156 (18.6%) patients had PenA, 53.3% were female and the median age was 67 years. Susceptibility results are summarized in Figure 3. H. influenzae isolated from sputum: A total 719 samples were included, 122/719 (15.8%) patients had PenA, 55.9% were female and median age was 67 years. Susceptibility results are summarized in Figure 4.

Conclusions

PenA prevalence differs across different patient populations. A higher proportion of patients with PenA had resistance in S. pneumoniae sputum isolates compared with those without, however this finding did not meet statistical significance. Further studies evaluating the impact of PenA on AMR need to be conducted.

825 DEVELOPMENT OF THE ANTICHOLINERGIC MEDICATION INDEX (ACMI)

Introduction

Medications with Anticholinergic (AC) properties, are prescribed to treat a range of conditions. Older people are increasingly likely to be prescribed multiple AC medications, but are also more likely to experience unwanted adverse effects, such as falls and delirium. The risks of adverse outcomes increase with the number and potency of AC medications prescribed. The aim of this study was to use a prognostic modelling approach to develop an AC Medication Index (ACMI) that identifies patients at high risk of AC medication side effects.

Methods

The prognostic model was developed using data on patients aged 65–95 years, registered with a general practice contributing data to ‘Connected Bradford’ in 2019. A Time-dependent Cox model was fitted, with hospital admission for delirium or falls as the composite outcome and AC medications, age, sex and important clinical factors (e.g. dementia, arthritis, urinary incontinence) as predictors. Concordance and Negalkerke’s R2 derived from five-fold cross-validation were used to assess model performance.

Results

There were 151,604 patients included in the study, of whom 47,035 (31.0%) were prescribed ≥1 AC medication during 2019. Codeine, Prednisolone, Furosemide and Amitriptyline were most commonly prescribed with 7.4%, 4.0%, 3.8% and 3.1% of patients prescribed these medications at least once in 2019, respectively. During 2019, 6,078 (4.0%) patients experienced a hospital admission with delirium or a fall, with the rate being increased in those prescribed ≥1 AC medication during 2019 (4.8% vs 3.7%; p &lt; 0.001). The prognostic model yielded a discrimination statistic of 0.86 with an R2 of 0.1.

Conclusion

The model used to develop the ACMI shows good discrimination. External validation will soon be performed using data from the SAIL databank and the ACMI will be further developed as a tool for use in primary care.

Factors associated with non-essential workplace attendance during the COVID-19 pandemic in the UK in early 2021: evidence from cross-sectional surveys

Objectives

Working from home where possible is important in reducing the spread of COVID-19. In early 2021, a quarter of people in England who believed they could work entirely from home reported attending their workplace. To inform interventions to reduce this, this study examined associated factors.

Study design

Data from the ongoing COVID-19 Rapid Survey of Adherence to Interventions and Responses survey series of nationally representative samples of people in the UK aged 16+ years in January–February 2021 were used.

Methods

The study sample was 1422 respondents who reported that they could work completely from home. The outcome measure was self-reported workplace attendance at least once during the preceding week. Factors of interest were analysed in three blocks: 1) sociodemographic variables, 2) variables relating to respondents’ circumstances and 3) psychological variables.

Results

26.8% (95% confidence interval [CI] = 24.5%–29.1%) of respondents reported having attended their workplace at least once in the preceding week. Sociodemographic variables and living circumstances significantly independently predicted non-essential workplace attendance: male gender (odds ratio [OR] = 1.85, 95% CI = 1.33–2.58); dependent children in the household (OR = 1.65, 95% CI = 1.17–2.32); financial hardship (OR = 1.14, 95% CI = 1.08–1.21); lower socio-economic grade (C2DE; OR = 1.65, 95% CI = 1.19–2.53); working in sectors such as health or social care (OR = 4.18, 95% CI = 2.56–6.81), education and childcare (OR = 2.45, 95% CI = 1.45–4.14) and key public service (OR = 3.78, 95% CI = 1.83–7.81) and having been vaccinated (OR = 2.08, 95% CI = 1.33–3.24).

Conclusions

Non-essential workplace attendance in the UK in early 2021 during the COVID-19 pandemic was significantly independently associated with a range of sociodemographic variables and personal circumstances. Having been vaccinated, financial hardship, socio-economic grade C2DE, having a dependent child at home and working in certain key sectors were associated with higher likelihood of workplace attendance.

"Strong Teeth": an early-phase study to assess the feasibility of an oral health intervention delivered by dental teams to parents of young children

BACKGROUND

Tooth decay (caries) is a significant health burden in young children. There is strong evidence for the benefits of establishing appropriate home-based oral health behaviours in early childhood. Dental teams are well placed to provide this information and there is clear advice on what oral health information should be given to parents. However, research has shown that there is limited guidance, training and resources on how dental teams should deliver this advice. "Strong Teeth" is a complex oral health intervention, using evidence-based resources and training underpinned by behaviour change psychology, to support behaviour change conversations in dental practice. This early phase evaluation aims to assess the feasibility of this intervention, prior to a full-scale trial.

METHODS

The study recruited 15 parents of children aged 0-2-years-old and 21 parents of children aged 3-5 years old, from five NHS dental practices across West Yorkshire. Participant demographics, self-reported brushing behaviours, dietary habits, a dental examination and three objective measures of toothbrushing were collected in a home-setting at baseline, then at 2-weeks and 2-months post-intervention. Recruitment, retention and intervention delivery were analysed as key process outcomes. Brushing habits were compared to national toothbrushing guidelines - the Delivering Better Oral Health toolkit (Public Health England).

RESULTS

Strong Teeth was feasible to deliver in a General Dental Practice setting in 94% of cases. Feasibility of recruitment (37%) exceeded progression criterion, however retention of participants (75%) was below the progression criterion for the 0-2 age group. More than half of children recruited aged 3-5-years had caries experience (52%). Total compliance to toothbrushing guidance at baseline was low (28%) and increased after the intervention (52%), an improvement that was statistically significant. Dietary habits remained largely unchanged. Plaque scores significantly decreased in the 3-5-year-olds and toothbrushing duration increased in all age groups.

CONCLUSION

"Strong Teeth" intervention delivery and data collection in the home setting was feasible. There was a positive indication of impact on reported toothbrushing behaviours. Some amendments to study design, particularly relating to the inclusion of the 0-2-year-old group, should be considered before progression to a full trial. Trial registration ISRCTN Register: ISRCTN10709150. Registered retrospectively 24/7/2019.

The impact of penicillin allergy de-labelling on the WHO AWaRe antibiotic categories: a retrospective cohort study

BACKGROUND

The WHO's AWaRe classification categorizes antibiotics into three stewardship groups: Access, Watch and Reserve. The Access group includes antibiotics with lower resistance potential than antibiotics in the other two groups. The UK five-year AMR strategy has set targets for reducing non-Access antibiotic use. The majority of penicillins are in the Access group and therefore patients with a penicillin allergy record are likely to receive more non-Access antibiotics. This study aimed to quantify the impact of penicillin allergy records on non-Access antibiotic prescribing and to estimate potential reductions in non-Access antibiotic use through penicillin allergy de-labelling.

METHODS

Inpatients of a 750-patient-bed UK district general hospital in England prescribed antibiotics between 1^st April 2018 and 31^st March 2019 were included. Variables included: age, sex, co-morbidity, infection treated, antibiotic usage, hospital length of stay, penicillin allergy status. Multivariable logistic regression was used to explore the association between patient characteristics and their receipt of antibiotics in the Access and non-Access groups.

RESULTS

A total of 67,059 antibiotic prescriptions for 23,356 inpatients were analysed. Penicillin allergy records were present in 14.3% of hospital admissions. Patients with a penicillin allergy record were around four times more likely (odds ratio = 4.7) to receive an antibiotic from the non-Access groups (i.e. Reserve and Watch groups). We estimate de-labelling 50% of hospital inpatients with a penicillin allergy record could reduce non-Access antibiotic use by 5.8% and total antibiotic use by 0.86%.

CONCLUSION

Penicillin allergy records are associated with non-Access antibiotic prescribing. Penicillin allergy de-labelling has potential to reduce non-Access antibiotic use.

Abstract P3-10-12: ERBB2 copy number analysis of invasive breast carcinoma using digital droplet PCR and targeted next-generation sequencing: A focus on 'non-classical' HER2 FISH groups using the 2018 ASCO/CAP HER2 testing guideline

Background: Non-classical HER2 FISH results were recently reclassified in the 2018 HER2 guidelines update, and concurrent IHC testing was recommended as part of additional workup to determine the final HER2 status in these groups. In this study, we explored the genomic landscape of HER2 FISH groups using digital droplet PCR (ddPCR) and targeted next-generation sequencing (NGS) on invasive breast carcinomas.

Methods: Fifty-one clinical samples with HER2 FISH and IHC results were included in our analysis and classified into FISH groups based on the updated 2018 ASCO/CAP HER2 testing guideline: (i) Group 1A with ratio ≥2 and signals/cell ≥6, (ii) Group 1B with ratio ≥2 and signals/cell ≥4 and &lt;6, (iii) Group 2 with ratio ≥2 and signals/cell &lt;4, (iv) Group 3 with ratio &lt;2 and signals/cell ≥6, (v) Group 4 with ratio &lt;2 and signals/cell ≥4 and &lt;6, and (vi) Group 5 with ratio &lt;2 and signals/cell &lt;4. Formalin-fixed paraffin-embedded samples were analyzed using two ddPCR assays each targeting an exon in the ERBB2 tyrosine kinase domain (exon 19 and 21, respectively) and a 130-gene NGS-based assay. For ddPCR, ERBB2 amplification status was determined from ddPCR ratios by using a recently published algorithm (Otsuji et al. 2017). For targeted NGS, ERBB2 amplification was called when copy number gains were detected in the majority of exons in ERBB2 (&gt;50% of exons).

Results: Mean ddPCR ratios varied amongst the different FISH groups (P &lt; 0.0001). As expected, patients with Group 1A had the highest mean ddPCR ratios compared to those with other FISH findings (P &lt; 0.0001). Furthermore, there was a correlation between ERBB2 ddPCR ratios and HER2 FISH ratios (ρe19 = 0.4435, P = 0.001 and ρe21 = 0.4644, P = 0.0006). Using ddPCR, ERBB2 amplifications were detected in all classically amplified Group 1A cases (5/5) and in none of the classically non-amplified Group 5 cases (0/12). Interestingly, ddPCR assays called ERBB2 amplification in four cases with non-classical results: one in Group 2 (1/6), two in Group 3 (2/6), and one in Group 4 (1/17), including two cases in Groups 3 and 4 which also showed concomitant HER2 overexpression by IHC (3+). Similarly, targeted NGS revealed ERBB2 amplification in all Group 1A cases (5/5) and in none of the Group 5 cases (0/12). Furthermore, NGS detected amplification in three non-classical cases: one in Group 1B (1/5), one in Group 3 (1/6), and one in Group 4 (1/17), including one case in Group 1B which was not called amplified by ddPCR. Notably, the three cases with amplification by NGS were the only three cases in the non-classical groups with HER2 overexpression by IHC. Overall, there was a strong concordance between ERBB2 amplification status by ddPCR/NGS and HER2 overexpression by IHC (κe19 = 0.79, κe21 = 0.92, κNGS = 1.0).

Conclusion: ERBB2 amplification using ddPCR and NGS is correlated with HER2 overexpression in both classical and non-classical FISH groups, thus providing genomic evidence to support the recent recommendation for concurrent IHC testing in cases with unusual FISH results. Our findings also highlight a potential role of ddPCR and targeted NGS in the workup of challenging HER2 cases.

Citation Format: Yang S-R, Bouhlal Y, De La Vega FM, Ballard M, West RB, Sibley RK, Kuo CJ, Vilborg A, Allison KH. ERBB2 copy number analysis of invasive breast carcinoma using digital droplet PCR and targeted next-generation sequencing: A focus on 'non-classical' HER2 FISH groups using the 2018 ASCO/CAP HER2 testing guideline [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-10-12.

Abstract P2-07-07: Development of a machine learning-based classifier for Oncotype DX® category prediction in a population of lymph node positive breast carcinoma patients

INTRODUCTION: Oncotype DX® (ODX) Assay is a valuable prognostic and predictive tool in ER+, Her2- invasive breast cancer (IBC). Initially tested and validated in lymph node (LN) negative patients, the indications of this test have been expanded to include patients with limited LN-positive disease. Several prediction systems have been developed to predict the ODX Recurrence Score (RS) with substantial performance in predicting a high vs low RS score but with low performance when predicting the 3 classes that compose the standard ODX. Additionally, many of these prediction systems have not been developed and/or tested for a population of LN+ patients.

OBJECTIVES: The primary objective of this study was to evaluate the performance of several previously published ODX RS predictive systems in a population of LN+ patients. Furthermore, we developed a machine-learning based classification system to accurately predict the ODX 3 category RS for this specific population.

METHODS: We conducted a retrospective search of Stanford's pathology database for all patients with LN+ IBC diagnosed between January 2013 and December 2017 with an ODX RS available. A total of 119 patients were identified for inclusion in this cohort. Our multivariate pathologic feature-based discriminatory model aimed to classify each case as belonging to the low, intermediate or high ODX RS category. We performed model validation by the 10-fold cross validation (10F-CV) method. The model's performance was assessed by comparing simple accuracy, balanced accuracy, F1 score (harmonic average of the precision and recall) and several concordance classification metrics.

RESULTS: Of the evaluated methods, Magee equations performed well in this population of LN+ patients with the modified Magee equation 2 displaying the best accuracy (70.9%) which was surprisingly better than originally reported (55.8%, in Klein et al. Mod Path. 2013). After an initial screen of methods and tuning of the best performing model, our model achieved an overall accuracy of 78.1% on 10F-CV with a 79.1 % balanced accuracy and no two-step discordances. This corresponded to an increase of weighted Cohen's kappa of 30% versus the best performing Magee equation in this cohort and an increase of 103% versus the modified Magee 1 equation (which uses the same features as our model except for tumor grade).

DISCUSSION: Classifiers aimed at providing an alternative to Oncotype DX testing are available and perform consistently across datasets. We are currently validating our approach in a population of 1000 LN-negative patients from the MSKCC and the SEER database. Due to the substantial performance of our machine learning-based classifier based on standard reported pathologic features, our model may be considered an alternative to the ODX standard testing or a screening method for ODX testing, especially for cases with where the cost and availability of the ODX test are a concern.

Citation Format: Beca F, Yang S-R, Gruber JG, Barry-Holson K, West R, Wen HY, Allison KH. Development of a machine learning-based classifier for Oncotype DX® category prediction in a population of lymph node positive breast carcinoma patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-07-07.

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

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

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

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

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

Citation Format: Caswell-Jin JL, McNamara K, Reiter JG, Sun R, Hu Z, Ma Z, Suarez CJ, Tilk S, Raghavendra A, Forte V, Chin S-F, Bardwell H, Provenzano E, Caldas C, Lang J, West R, Tripathy D, Press MF, Curtis C. Clonal evolution and heterogeneity in breast tumors treated with neoadjuvant HER2-targeted therapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-06-01.

A longitudinal study into the reciprocal effects of identities and smoking behaviour: Findings from the ITC Netherlands Survey

OBJECTIVE

Although it has been found that identity constructs related to smoking are associated with changes in smoking behaviour, the direction of causal associations is as yet unclear. This study aims to clarify the nature and direction of these associations.

METHODS

In this longitudinal study we examined the reciprocal relations between identity constructs (i.e., smoker self-identity, quitter self-identity and smoker group-identity), intention to quit and smoking and quitting behaviour among a sample of 1036 smokers and ex-smokers, using cross-lagged structural equation modelling. Moreover, we tested whether these relations differed by socio-economic status (SES).

RESULTS

Identity and smoking behaviour were reciprocally related in that in intention to quit and smoking behaviour consistently predicted identity change, and identity predicted (changes in) intentions to quit and smoking behaviour. Behaviour appears more important for identity change than identity for behaviour change. Furthermore, quitter self-identity appears more important than smoker self- and group-identity. Relationships did not differ significantly between SES-groups. The findings were replicated using a cross-validation sample.

CONCLUSION

Results imply that changing smoking behaviour may be a vehicle to change smoking-related identity. Moreover, strengthening identification with quitting is more crucial for quit success than decreasing smoker identities. The finding that behaviour may be more important for identity than vice versa, if replicated, may call for additions to identity theories.

Natural disaster management: experience of an academic institution after a 7.8 magnitude earthquake in Ecuador

OBJECTIVES

This case study describes the implementation of an academic institution's disaster management plan.

STUDY DESIGN

Case study.

METHODS

USFQ's Medical School developed a six-phase disaster relief plan consisting of: induction, establishing a base camp, crisis management and mental health aid, creation of multidisciplinary teams and multi-agency teams, and reconstruction. Each phase uses a community-oriented approach to foster survivor autonomy and recovery.

RESULTS

Our methodology facilitated the successful implementation of multidisciplinary interventions to manage the earthquake's aftermath on the personal, community and regional levels, treated and prevented psychological and physical morbidity among survivors and promoted healthy living conditions and independence.

CONCLUSIONS

A multidisciplinary response team that addresses medical needs, mental health, education, food, nutrition and sanitation is highly effective in contributing to timely, effective relief efforts. The short- and long-term solutions we describe could be applicable to other academic centres' interventions in future disaster scenarios around the world.

Factors associated with study attrition in a pilot randomised controlled trial to explore the role of exercise-assisted reduction to stop (EARS) smoking in disadvantaged groups

Background

Study attrition has the potential to compromise a trial’s internal and external validity. The aim of the present study was to identify factors associated with participant attrition in a pilot trial of the effectiveness of a novel behavioural support intervention focused on increasing physical activity to reduce smoking, to inform the methods to reduce attrition in a definitive trial.

Methods

Disadvantaged smokers who wanted to reduce but not quit were randomised (N = 99), of whom 61 (62 %) completed follow-up assessments at 16 weeks. Univariable logistic regression was conducted to determine the effects of intervention arm, method of recruitment, and participant characteristics (sociodemographic factors, and lifestyle, behavioural and attitudinal characteristics) on attrition, followed by multivariable logistic regression on those factors found to be related to attrition.

Results

Participants with low confidence to quit, and who were undertaking less than 150 mins of moderate and vigorous physical activity per week at baseline were less likely to complete the 16-week follow-up assessment. Exploratory analysis revealed that those who were lost to follow-up early in the trial (i.e., by 4 weeks), compared with those completing the study, were younger, had smoked for fewer years and had lower confidence to quit in the next 6 months. Participants who recorded a higher expired air carbon monoxide reading at baseline were more likely to drop out late in the study, as were those recruited via follow-up telephone calls. Multivariable analyses showed that only completing less than 150 mins of physical activity retained any confidence in predicting attrition in the presence of other variables.

Conclusions

The findings indicate that those who take more effort to be recruited, are younger, are heavier smokers, have less confidence to quit, and are less physically active are more likely to withdraw or be lost to follow-up.

Hyaluronic Acid Binding Sperm Selection for assisted reproduction treatment (HABSelect): study protocol for a multicentre randomised controlled trial

INTRODUCTION

The selection of a sperm with good genomic integrity is an important consideration for improving intracytoplasmic sperm injection (ICSI) outcome. Current convention selects sperm by vigour and morphology, but preliminary evidence suggests selection based on hyaluronic acid binding may be beneficial. The aim of the Hyaluronic Acid Binding Sperm Selection (HABSelect) trial is to determine the efficacy of hyaluronic acid (HA)-selection of sperm versus conventionally selected sperm prior to ICSI on live birth rate (LBR). The mechanistic aim is to assess whether and how the chromatin state of HA-selected sperm corresponds with clinical outcomes-clinical pregnancy rate (CPR), LBR and pregnancy loss (PL).

METHODS AND ANALYSIS

Couples attending UK Centres will be approached, eligibility screening performed and informed consent sought. Randomisation will occur within 24 hours prior to ICSI treatment. Participants will be randomly allocated 1:1 to the intervention arm (physiological intracytoplasmic sperm injection, PICSI) versus the control arm using conventional methods (ICSI). The primary clinical outcome is LBR ≥37 weeks' gestation with the mechanistic study determining LBR's relationship with sperm DNA integrity. Secondary outcomes will determine this for CPR and PL. Only embryologists performing the procedure will be aware of the treatment allocation. Steps will be taken to militate against biases arising from embryologists being non-blinded. Randomisation will use a minimisation algorithm to balance for key prognostic variables. The trial is powered to detect a 5% difference (24-29%: p=0.05) in LBR ≥37 weeks' gestation. Selected residual sperm samples will be tested by one or more assays of DNA integrity.

ETHICS AND DISSEMINATION

HABSelect is a UK NIHR-EME funded study (reg no 11/14/34; IRAS REF. 13/YH/0162). The trial was designed in partnership with patient and public involvement to help maximise patient benefits. Trial findings will be reported as per CONSORT guidelines and will be made available in lay language via the trial web site (http://www.habselect.org.uk/).

TRIAL REGISTRATION NUMBER

ISRCTN99214271; Pre-results.

Development of the Awareness of Cultural Safety Scale: A pilot study with midwifery and nursing academics

BACKGROUND

Rates of academic success of Indigenous students compared to other students continues to be significantly lower in many first world countries. Professional development activities for academics can be used to promote teaching, learning and support approaches that value Indigenous worldviews. However, there are few valid and reliable tools that measure the effect of academic development strategies on awareness of cultural safety.

OBJECTIVES

To develop and validate a self-report tool that aims to measure nursing and midwifery academics' awareness of cultural safety.

METHODS

This study followed a staged model for tool development. This included: generation of items, content validity testing and expert Indigenous cultural review, administration of items to a convenience sample of academics, and psychometric testing. An online survey consisting of demographic questions, Awareness of Cultural Safety Scale (ACSS), and awareness of racism items was completed by academics undertaking a professional development program on cultural safety.

FINDINGS

Ratings by experts revealed good content validity with an index score of 0.86. The 12-item scale demonstrated good internal reliability (Cronbach's alpha of 0.87). An evaluation of construct validity through factor analysis generated three factors with sound internal reliability: Factor 1 (Cultural Application, Cronbach's alpha=.85), Factor 2 (Cultural Support, Cronbach's alpha=.70) and Factor 3 (Cultural Acknowledgement, Cronbach's alpha=.85). The mean total scale score was 46.85 (SD 7.05, range 31-59 out of a possible 60). There was a significant correlation between scores on the Awareness of Cultural Safety Scale and awareness of racism scores (r=.461, p=.002).

CONCLUSION

Awareness of cultural safety is underpinned by principles of respect, relationships, and responsibility. Results indicated the ACSS was valid and reliable. Completion of the scale aimed to foster purposeful consideration by nursing and midwifery academics about their perceptions and approaches to teaching in order to improve Indigenous student success.

Molecular Structures of N,N'-Dimethylbenzimidazoline-2-germylene and -stannylene in Solution and in Solid State by Means of Optical (Raman and UV-vis) Spectroscopy and Quantum Chemistry Methods

X-ray data obtained for germylene 1 evidence its monomeric structure, unlike that of stannylene 2, which had been shown previously to form a coordination dimer. Raman spectra of solid and liquid 1 are identical, whereas the Raman spectra of solid 2 and its solution 2a differ significantly. The spectrum of 2 is complicated and contains the lines corresponding to N → Sn coordination bonds forming a dimer. The spectrum of 2a is simpler and close to that of monomeric 1, thus pointing to the rupture of the dimer in solution. The UV-vis spectrum of solid 2 exhibits a band corresponding to a transition involving the N → Sn coordination bonds. Quantum theory of atoms in molecules data estimate the energy of this bond as ∼19 kcal/mol. The aromaticity of 1 and 2 with their 10 π-electron systems including divalent Ge or Sn atoms is confirmed by negative nucleus-independent chemical shift values.

Integrated systematic review on educational strategies that promote academic success and resilience in undergraduate indigenous students

BACKGROUND

Despite numerous recommendations by governments, researchers, and education policymakers the recruitment, retention and success of undergraduate indigenous students in higher education is not commensurate of the wider student population. There is minimal evidence of valuing indigenous worldviews and perspectives in curricula, and effectiveness of educational strategies to strengthen indigenous student success rates in completing undergraduate studies.

OBJECTIVES

To conduct an integrative systematic review of educational strategies to promote academic success and resilience in undergraduate indigenous students.

METHODS

Major databases of Scopus, ProQuest, Informit and Web of Science were searched. Inclusion criteria were peer reviewed research articles from scholarly journals that referenced indigenous, aboriginal, First Nation or Māori students in undergraduate programs in higher education. The search was limited to English language and studies conducted from 1995 to 2014.

RESULTS

The search yielded 156 research papers which reduced to 16 papers that met the inclusion criteria. The included papers were critiqued from a standpoint theory approach that reflects feminism, cultural respect, and humanism. Much of the literature describes issues, and provides qualitative analyses of experiences, but empirical evaluations of interventions are rare.

CONCLUSIONS

There was a gap in current research evaluating strategies to improve indigenous student success and resilience. Key strategies for indigenous student success are multi-faceted, layered support, underpinned by the principles of respect, relationships, and responsibility. Implications for nursing and midwifery education, research and health care practice are outlined.

Use of screening tests, diagnosis wait times, and wait-related satisfaction in breast and prostate cancer

BACKGROUND

Understanding factors relating to the perception of wait time by patients is key to improving the patient experience.

METHODS

We surveyed 122 breast and 90 prostate cancer patients presenting at clinics or listed on the cancer registry in Newfoundland and Labrador and reviewed their charts. We compared the wait time (first visit to diagnosis) and the wait-related satisfaction for breast and prostate cancer patients who received regular screening tests and whose cancer was screening test-detected ("screen/screen"); who received regular screening tests and whose cancer was symptomatic ("screen/symptomatic"); who did not receive regular screening tests and whose cancer was screen test-detected ("no screen/screen"); and who did not receive regular screening tests and whose cancer was symptomatic ("no screen/symptomatic").

RESULTS

Although there were no group differences with respect to having a long wait (greater than the median of 47.5 days) for breast cancer patients (47.8% screen/screen, 54.7% screen/symptomatic, 50.0% no screen/ screen, 40.0% no screen/symptomatic; p = 0.814), a smaller proportion of the screen/symptomatic patients were satisfied with their wait (72.5% screen/ screen, 56.4% screen/symptomatic, 100% no screen/ screen, 90.9% no screen/symptomatic; p = 0.048). A larger proportion of screen/symptomatic prostate cancer patients had long waits (>104.5 days: 41.3% screen/screen, 92.0% screen/symptomatic, 46.0% no screen/screen, 40.0% no screen/symptomatic; p = 0.011) and a smaller proportion of screen/ symptomatic patients were satisfied with their wait (71.2% screen/screen, 30.8% screen/symptomatic, 76.9% no screen/screen, 90.9% no screen/symptomatic; p = 0.008).

CONCLUSIONS

Diagnosis-related wait times and satisfaction were poorest among patients who received regular screening tests but whose cancer was not detected by those tests.

191 ROBUST GENERATION OF NEURAL STEM CELLS FROM PIG INDUCED PLURIPOTENT STEM CELLS FOR TRANSLATIONAL NEURAL REGENERATIVE MEDICINE

The generation of pig induced pluripotent stem cells (iPSC) opened the possibility to evaluate autologous neural cell therapy as a viable option for human patients. However, it is necessary to demonstrate whether pig iPSC are capable of in vitro neural differentiation similar to human iPSC in order to perform in vitro and in vivo comparative studies. Multiple laboratories have generated pig iPSC that have been characterised using pluripotent markers such as SSEA4 and POU5F1. However, correlations of pluripotent marker expression profiles among iPSC lines and their neural differentiation potential has not been fully explored. Because neural rosettes (NR) are composed of neural stem cells, our goal was to demonstrate that NR from pig iPSC can be generated, isolated, and expanded in vitro from multiple porcine iPSC lines similar to human iPSC and that the level of pluripotency in the starting porcine iPSC population (POUF51 and SSEA4 expression) could influence NRs development. Three lines of pig iPSC L1, L2, and L3 were cultured on matrigel-coated plates in mTeSR1 medium (Stemcell Technologies Inc., Vancouver, BC, Canada) and passaged every 3 to 4 days. For neural induction (NI), pig iPSC were disaggregated using dispase and plated. After 24 h, cells were maintained in N2 media [77% DMEM/F12, 10 ng mL–1 bovine fibroblast growth factor (bFGF), and 1X N2] for 15 days. To evaluate the differentiation potential to neuron and glial cells, NR were isolated, expanded in vitro and cultured for three weeks in AB2 medium (AB2, 1X ANS, and 2 mM L-Glutamine). Immunostaining assays were performed to determine pluripotent (POU5F1 and SSEA4), tight junction (ZO1), neural epithelial (Pax6 and Sox1), neuron (Tuj1), astrocyte (GFAP), and oligodendrocyte (O4) marker expression. Line L2 (POU5F1high and SSEA4low) showed a high potential to form NR (6.3.5%, P < 0.05) in comparison to the other 2 lines L1 (POU5F1low and SSEA4low) and L3 (POU5F1low and SSEA4high) upon NI. The NR immunocytochemistry results from Line L2 showed the presence of Pax6+ and Sox1– NRs cells at day 9 post-neural induction and that ZO1 started to localise at the apical border of NRs. At day 13, NRs cells were Pax6+ and Sox1+, and ZO1 was localised to the lumen of NR. After isolation and culture in vitro, NR cells expressed transcription factors PLAGL1, DACH1, and OTX2 through 2 passages, but were not detected in later passages. However, rosette cytoarchitecture was present up until passage 7 and were still Pax6+/Sox1+. NRs at passage 2 were cryopreserved and upon thaw showed normal NR morphology and were Pax6+/Sox1+. To characterise the plasticity of NRs, cells were differentiated. Tuj1 expression was predominant after differentiation indicating a bias towards a neuron phenotype. These results demonstrate that L2 pig iPSC (POUF51high and SSEA4low) have a high potential to form NR and neural differentiation parallels human iPSC neurulation events. Porcine iPSC should be considered as a large animal model for determining the safety and efficacy of human iPSC neural cell therapies.

Changes in prevalence of depression and anxiety following smoking cessation: results from an international cohort study (ATTEMPT)

BACKGROUND

Smoking cessation improves physical health but it has been suggested that in vulnerable individuals it may worsen mental health. This study aimed to identify the short- and longer-term effects of stopping smoking on depression and anxiety in the general population and in those with a history of these disorders.

METHOD

Sociodemographic and smoking characteristics, and mental and physical health were assessed using established measures in the ATTEMPT cohort, an international longitudinal study of smokers (n = 3645). Smokers who had stopped for at least 3 months or less than 3 months at the 12-month follow-up were compared with current smokers (n = 1640).

RESULTS

At follow-up, 9.7% [95% confidence interval (CI) 8.3-11.2] of smokers had stopped for less than 3 months and 7.5% (95% CI 6.3-8.9) for at least 3 months. Compared with current smokers, prevalence of depression prescriptions obtained in the last 2 weeks was lower for those who had stopped for less than 3 months [odds ratio (OR) 0.37, 95% CI 0.14-0.96] or at least 3 months (OR 0.25, 95% CI 0.06-0.94) after adjusting for baseline prescription levels and confounding variables. Adjusted prevalence of recent depression symptoms was also lower for ex-smokers who had stopped for less than 3 months (OR 0.34, 95% CI 0.15-0.78) or at least 3 months (OR 0.24, 95% CI 0.09-0.67) than among continuing smokers. There was no change in anxiety measures in the general population or any increase in anxiety or depression symptoms in ex-smokers with a past history of these conditions.

CONCLUSIONS

Smoking cessation does not appear to be associated with an increase in anxiety or depression and may lead to a reduced incidence of depression.

The impact of traumatic pelvic fractures on sporting activity and quality of life

BACKGROUND

Pelvic fractures (PFX) reflect high-energy trauma with high mortality and morbidity.

AIM

We attempted to determine: whether there is a decrease in levels of sporting and physical activity in patients with operatively-treated PFX; risk factors for decreased sporting activity; any correlation between sporting activity and quality of life in this group.

METHODS

Retrospective demographics on mechanism of injury, fracture type, associated injury and injury severity score, as well as prospective documentation of the level and frequency of sporting activity, were collected from adult patients treated operatively for a PFX between 2007 and 2010, using a specifically designed questionnaire. Quality of life before and after injury was also recorded using the EuroQol-5D health-outcome tool.

RESULTS

80 patients without pre-existing musculoskeletal disability were enrolled. The mean age was 44.9 years (18-65). The mean follow-up was 30.5 months (12-39). A decrease in level and frequency of sporting activity was observed. It was associated with lower-extremity associated injuries, but not with injury severity score, PFX severity, PFX type, age, or timing of follow-up. Sporting activity before injury predicted higher levels of sporting participation after injury. Decreased sporting activity after injury was associated with decreased EuroQol-SD score.

CONCLUSIONS

Patients should be counselled on the likelihood of a reduction in sporting activities after surgically treated PFX. A larger multi-centre study is needed to further expand on the evidence of the true impact of PFX and its associated injuries on sporting activity.

Abstract P1-02-10: Variation in HER2 positive rates in California by geographic region: Implications for setting pathology laboratory benchmarks

Background: It is unclear how much regional variation there is for HER2 positive rates in breast cancer. By looking at regional variation, we can begin to examine the impact of both demographic variation and pathology laboratory practice on HER2 positive rates so that valid laboratory benchmarks can be established.

Methods: Utilizing data from the California Cancer Registry (CCR), we examined the HER2 positive rates sorted by 58 California counties. Counties were grouped into 10 geographic regions for analysis. Stage at presentation and total numbers of breast cancer cases were studied at as variables. Results: 97,248 breast cancer cases were included in the CCR data. Overall, the HER2 positive rate was 16.5%. HER2 positive rates increased with increasing stage at presentation both overall and by region. Overall they were 12.9% for stage 1, 17.4% for stage 2, 23.2% for stage 3, 25.9% for stage 4 and 25.2% for unstaged cases. There was significant regional variation in overall HER2 positive rates ranging from 13.2-18.9%. 4 regions had overall rates within 0.5% of each other, 3 regions had rates &gt; 0.5% below average and 3 regions had rates &gt;0.5% above average. In the regions with overall rates below the average, one region (region 4, N = 4,636) had lower rates across all stages, and two regions (region 7, N = 8,623 and region 8, N = 14,152) had lower rates only for stages 1-2. Of regions with overall rates higher than the average, one region had increased rates across all stages (region 9, N = 24,279) and two regions had increased rates only in stages 1-3 (region 5, N = 9,176 and region 6, N = 4,888).

Conclusions: In California, there is significant variation in HER2 positive rates by geographic region, even when controlling for stage. The possible influence of differences in regional population characteristics versus differences in laboratory practices to explain this variation should be further examined so that valid regional laboratory benchmarks can be established.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-02-10.

Responses by breast and prostate cancer patients to out-of-pocket costs in Newfoundland and Labrador

PURPOSE

Cancer patients face substantial care-related out-of-pocket (oop) costs that may influence treatment decisions, attitudes, and use of drug- or appointment-related cost-saving strategies. We examined the relationship between oop costs and care-related responses by patients.

METHODS

We surveyed 170 prostate and 131 breast cancer patients presenting at clinics or support groups, or listed on the cancer registry in Newfoundland and Labrador.

RESULTS

In the 3-month period before the survey, 18.8% of prostate and 25.2% of breast cancer patients had oop costs greater than $500. Those oop costs consumed more than 7.5% of quarterly household income for 15.9% of prostate and 19.1% of breast cancer patients. Few patients (8.8% prostate, 15.3% breast) ever adopted any drug- or appointment-related cost-saving strategy. Few patients (7.2% prostate, 9.6% breast) said oop costs influenced treatment decisions, told their physicians about their oop costs (27.0% prostate, 21.1% breast), or were aware of available financial assistance programs (27.3% prostate, 36.9% breast). Compared with patients having low or moderate oop costs (22.9% prostate, 16.7% breast, and 25.7% prostate, 58.3% breast respectively), a larger proportion of prostate (56.0%) and breast (58.3%) cancer patients with high oop costs said that those costs created stress. Among prostate cancer patients, a larger proportion of those having high oop costs (compared with low or moderate costs) used drug-related (22.2% vs. 3.3% and 9.6% respectively) and appointment-related (11.1% vs. 1.1% and 3.8% respectively) cost-saving strategies, said oop costs created an unusual amount of stress (48.0% vs. 18.4% and 10.4%), and had difficulty paying those costs (29.2% vs. 6.2% and 10.4%).

CONCLUSIONS

For a small group of breast and prostate cancer patients, oop costs are high, but rarely lead to the use of care-related cost-saving strategies or influence care decisions.

What is the effect of penicillin dosing interval on outcomes in streptococcal infective endocarditis?

OBJECTIVES

Penicillin is an important treatment option for streptococcal infective endocarditis (IE), but its short half-life requires frequent re-dosing (4- or 6-hourly). There is a variation between the dosing regimens in different guidelines and consequent differences in the dosing interval. The objective of this study was to examine the relationship between the penicillin dosing interval and outcomes in streptococcal IE.

METHODS

A retrospective study of cases of streptococcal IE was undertaken using the Leeds Endocarditis Service database. Cases were included if the first-line therapy had been penicillin and excluded if patients had received less than 72 h of therapy. Details of antimicrobial therapy and outcomes were collated using strict definitions. Various parameters were considered as independent variables in a multivariate logistic regression analysis. Univariate analysis of categorical data was carried out using a χ(2) test, and analysis of continuous data using an unpaired t-test.

RESULTS

Two hundred and twelve cases were included in the final analysis. Of the parameters considered, a 4-hourly dosing interval [unadjusted OR = 2.79 (95% CI 1.43-5.62)] and initial echocardiographic evidence of abscess or severe valve regurgitation [unadjusted OR = 0.30 (95% CI 0.13-0.66)] were the only statistically significant factors associated with the success or failure of penicillin therapy. The odds of a successful outcome were almost three times greater with a 4-hourly regimen than with a 6-hourly regimen. Failure of penicillin therapy had no correlation with the MIC of penicillin or the concurrent administration of gentamicin.

CONCLUSIONS

Penicillin continues to be an effective therapy for IE. This study suggests that a 4-hourly dosing interval may be relevant in predicting the success of initial medical therapy. Further prospective studies are warranted to evaluate relationships in more detail.

Predictive validity of the Motivation To Stop Scale (MTSS): a single-item measure of motivation to stop smoking

BACKGROUND

Many different measures of motivation to stop smoking exist but it would be desirable to have a brief version that is standard for use in population surveys and for evaluations of interventions to promote cessation. The aim of this study was to assess the predictive validity and accuracy of the single-item Motivation To Stop Scale (MTSS).

METHODS

This study is part of the "Smoking Toolkit Study;" a monthly survey of representative samples of the English population. We used data from 2483 respondents to the surveys from November 2008 to January 2011, who were smokers, used the MTSS, and were followed up 6 months later to provide information on quit attempts since baseline. The MTSS consists of one item with seven response categories ranging from 1 (lowest) to level 7 (highest level of motivation to stop smoking).

RESULTS

A total of 692 smokers (27.9% (95% CI=26.1-29.6)) made an attempt to quit smoking between baseline and 6-month follow-up. The odds of quit attempts increased linearly with increasing level of motivation at baseline (p<0.001) and were 6.8 (95% CI=4.7-9.9) times higher for the highest level of motivation compared with the lowest. The accuracy of the MTSS for discriminating between smokers who did and did not attempt to quit was ROC(AUC)=0.67 (95% CI=0.65-0.70).

CONCLUSIONS

The MTSS provides strong and accurate prediction of quit attempts and is a candidate for a standard single-item measure of motivation to stop smoking. Further research should assess the external validity of this measure in different smoking populations.

Abstract PD05-09: Whole-genome progression of breast cancer from early neoplasia to invasive carcinoma

Cancer evolution involves cycles of genomic damage, epigenetic deregulation, and increased cellular proliferation that eventually culminate in the carcinoma phenotype. Early breast neoplasias include usual ductal hyperplasia, columnar cell lesions, and flat epithelial atypia and some are thought to represent precursor stages. To elucidate their role in cancer evolution we performed comparative whole genome sequencing of early neoplasias, matched normal tissue, and carcinomas from six patients. The identified somatic mutations served as lineage markers to build trees that relate the tissue samples. On the basis of the lineage trees we inferred the order, timing, and rates of mutational events. We find that in a subset of cases, the last common ancestor of an early neoplasm and a carcinoma was hypermutated and had several aneuploidies, and that evolution further accelerated in the carcinoma lineage. In contrast to highly advanced tumors that are the focus of much of current cancer genome sequencing, the early neoplasia genomes, and the carcinomas as well, harbor a striking paucity of potentially functional somatic point mutations. The earliest significant events we could detect, those changes that occurred in common ancestors of neoplastic and tumor cells, are aneuploidies. Several aneuploidies are recurrent, suggesting that they are among the earliest genomic events that predispose breast tissue to eventual development of invasive carcinoma.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD05-09.