Microsecond dynamics control the HIV-1 Envelope conformation

The HIV-1 Envelope (Env) glycoprotein facilitates host cell fusion through a complex series of receptor-induced structural changes. Although remarkable progress has been made in understanding the structures of various Env conformations, microsecond timescale dynamics have not been studied experimentally. Here, we used time-resolved, temperature-jump small-angle x-ray scattering to monitor structural rearrangements in an HIV-1 Env SOSIP ectodomain construct with microsecond precision. In two distinct Env variants, we detected a transition that correlated with known Env structure rearrangements with a time constant in the hundreds of microseconds range. A previously unknown structural transition was also observed, which occurred with a time constant below 10 μs, and involved an order-to-disorder transition in the trimer apex. Using this information, we engineered an Env SOSIP construct that locks the trimer in the prefusion closed state by connecting adjacent protomers via disulfides. Our findings show that the microsecond timescale structural dynamics play an essential role in controlling the Env conformation with impacts on vaccine design.

Engineering immunogens that select for specific mutations in HIV broadly neutralizing antibodies

Vaccine development targeting rapidly evolving pathogens such as HIV-1 requires induction of broadly neutralizing antibodies (bnAbs) with conserved paratopes and mutations, and, in some cases, the same Ig-heavy chains. The current trial-and-error search for immunogen modifications that improve selection for specific bnAb mutations is imprecise. To precisely engineer bnAb boosting immunogens, we used molecular dynamics simulations to examine encounter states that form when antibodies collide with the HIV-1 Envelope (Env). By mapping how bnAbs use encounter states to find their bound states, we identified Env mutations that were predicted to select for specific antibody mutations in two HIV-1 bnAb B cell lineages. The Env mutations encoded antibody affinity gains and selected for desired antibody mutations in vivo. These results demonstrate proof-of-concept that Env immunogens can be designed to directly select for specific antibody mutations at residue-level precision by vaccination, thus demonstrating the feasibility of sequential bnAb-inducing HIV-1 vaccine design.

Quantifying the Travel Undertaken by Cancer Patients Receiving Radiotherapy in Victoria, Australia

PURPOSE/OBJECTIVE(S)

This study aimed to investigate the travel distance for cancer patients treated with radiotherapy in Victoria, Australia, during a 9-year period relative to their home address. Additionally, the study aimed to quantify 'excess' travel distance where patients travelled to treatment centers that were not their closest.

MATERIALS/METHODS

The PRedicting the health economic IMPact of new and current CAncer Treatments (PRIMCAT) dataset was used for the study. PRIMCAT is a multi-institution research initiative taking a data-driven modelling approach to understand and forecast cancer treatment utilization in Australia. The PRIMCAT dataset is a comprehensive linked dataset including a retrospective cohort of patients 18 years and over, diagnosed with cancer included in the Victorian Cancer Registry between January 2010 to December 2019. For each patient in the cohort, data linkage includes a range of datasets managed by state and federal health departments including the Victorian Radiotherapy Minimum Dataset. A distance matrix was constructed using the Google Distance Matrix API that included driving distance between postcodes of selected patients and the postcodes of radiotherapy facilities. The centroid of each post-code was used for driving distance measurements. We first analyzed the realized travel distances of patients followed by the excess travel by patients. The excess travel was further quantified separately for public and private radiotherapy facilities.

RESULTS

There were 86,408 unique patient-radiotherapy courses available and of sufficient data quality to analyze. Patients travelled an average of 42.5km (s.d. = 72.2km) one-way, with a median travel distance of 16.5km. The largest distance travelled was 723km with 95% of patients travelling between 0km and 257km. Of the patients who received radiotherapy in a public facility, 44.3% travelled to a facility that was not their closest public facility. The average excess travel of these patients was 26.8km, with the median excess travel being 13.6km. Additionally, of patients who received care in a public facility, 47.4% travelled past a closer private facility. The average excess travel distance of these patients was 23.1km and the median excess travel was 11.5km. In the case of patients who received radiotherapy at a private facility, 92.8% travelled to a clinic that was not their closest. The average excess of these patients was 36.6km with a median excess travel distance of 15.6km.

CONCLUSION

Access to radiotherapy facilities remains unequal in Victoria with some patients having to travel significantly greater distances than average. This significant travel may require patients to take time off work or live away from home presenting additional financial challenges. The reasons for the large travel distances and any excess travel have not yet been identified but will be the subject of further study.

Survey of New Zealand consumer attitudes to consumption of meat and meat alternatives

This study examined consumers' consumption, motivations, and concerns regarding meat and meat alternatives by means of an online survey of 1061 New Zealand consumers and review of literature. Outcomes of the survey indicate New Zealanders are overwhelmingly omnivorous (93%), regard taste as the most important factor in their meat purchasing decision followed by price and freshness and consider environmental impact and social responsibility of less importance. Those surveyed indicated willingness to pay 17-24% more for food safety and sustainability related meat attributes. About half of respondents lowered their meat consumption the previous year, mainly red and processed meats, due to lack of affordability and health concerns. Although those surveyed showed high awareness about meat alternatives, their consumption level of the products was very low and more prevalent for female, younger and more educated individuals. Overall, the outlook for meat consumption and meat industry in New Zealand is positive and is likely to remain so for the foreseeable future.

Microsecond dynamics control the HIV-1 envelope conformation

The HIV-1 Envelope (Env) glycoprotein facilitates host cell fusion through a complex series of receptor-induced structural changes. Although significant progress has been made in understanding the structures of various Env conformations and transition intermediates that occur within the millisecond timescale, faster transitions in the microsecond timescale have not yet been observed. In this study, we employed time-resolved, temperature-jump small angle X-ray scattering to monitor structural rearrangements in an HIV-1 Env ectodomain construct with microsecond precision. We detected a transition correlated with Env opening that occurs in the hundreds of microseconds range and another more rapid transition that preceded this opening. Model fitting indicated that the early rapid transition involved an order-to-disorder transition in the trimer apex loop contacts, suggesting that conventional conformation-locking design strategies that target the allosteric machinery may be ineffective in preventing this movement. Utilizing this information, we engineered an envelope that locks the apex loop contacts to the adjacent protomer. This modification resulted in significant angle-of-approach shifts in the interaction of a neutralizing antibody. Our findings imply that blocking the intermediate state could be crucial for inducing antibodies with the appropriate bound state orientation through vaccination.

International development of a patient-centered core outcome set for assessing health-related quality of life in metastatic breast cancer patients

PURPOSE

For patients living with metastatic breast cancer (MBC), achieving best possible health-related quality of life, along with maximizing survival, is vital. Yet, we have no systemic way to determine if we achieve these goals. A Core Outcome Set (COS) that allows standardized measurement of outcomes important to patients, but also promotes discussing these outcomes during clinical encounters, is long overdue.

METHODS

An international expert group (EG) of patient advocates, researchers, medical specialists, nurse specialists, and pharmaceutical industry representatives (n = 17) reviewed a list of relevant outcomes retrieved from the literature. A broader group (n = 141: patients/patient advocates (n = 45), health care professionals/researchers (n = 64), pharmaceutical industry representatives (n = 28), and health authority representatives (n = 4)) participated in a modified Delphi procedure, scoring the relevance of outcomes in two survey rounds. The EG finalized the COS in a consensus meeting.

RESULTS

The final MBC COS includes 101 variables about: (1) health-related quality of life (HRQoL, n = 26) and adverse events (n = 24); (2) baseline patient characteristics (n = 9); and (3) clinical variables (n = 42). Many outcome that cover aspects of HRQoL relevant to MBC patients are included, e.g. daily functioning (including ability to work), psychosocial/emotional functioning, sexual functioning, and relationship with the medical team.

CONCLUSION

The COS developed in this study contains important administrative data, clinical records, and clinician-reported measures that captures the impact of cancer. The COS is important for standardization of clinical research and implementation in daily practice and has received accreditation by the International Consortium for Health Outcomes Measurement (ICHOM).

Network analysis uncovers the communication structure of SARS-CoV-2 spike protein identifying sites for immunogen design

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has triggered myriad efforts to understand the structure and dynamics of this complex pathogen. The spike glycoprotein of SARS-CoV-2 is a significant target for immunogens as it is the means by which the virus enters human cells, while simultaneously sporting mutations responsible for immune escape. These functional and escape processes are regulated by complex molecular-level interactions. Our study presents quantitative insights on domain and residue contributions to allosteric communication, immune evasion, and local- and global-level control of functions through the derivation of a weighted graph representation from all-atom MD simulations. Focusing on the ancestral form and the D614G-variant, we provide evidence of the utility of our approach by guiding the selection of a mutation that alters the spike's stability. Taken together, the network approach serves as a valuable tool to evaluate communication "hot-spots" in proteins to guide design of stable immunogens.

Exploring Ductility in Dental Ceramics

Two damage regimes-"brittle" and "ductile"-have been identified in the literature on ceramic grinding, machining, grit blasting, and wear. In the brittle regime, the damage mechanism is essentially crack formation, while in the ductile region, it is quasiplasticity. Onset of the brittle mode poses the greater threat to strength, so it becomes important to understand the mechanics of ductile-brittle thresholds in these materials. Controlled microcontact tests with a sharp indenter are employed to establish such thresholds for a suite of contemporary computer-aided design/computer-aided manufacturing dental ceramics. Plots of flexural strength S versus indentation load P show a steep decline beyond the threshold, consistent with well-established contact mechanics relations. Threshold dimensions occur on a scale of order 1 µm and contact load of order 1 N, values pertinent to practical grit finishing protocols. The ductile side of ceramic shaping is accessed by reducing grit sizes, applied loads, and depths of cut below critical levels. It is advocated that critical conditions for ductile shaping may be most readily quantified on analogous S(P) plots, but with appropriate machining variable (grit size, depths of cut, infeed rate) replacing load P. Working in the ductile region offers the promise of compelling time and cost economies in prosthesis fabrication and preparation.

Priority recommendations for the implementation of patient-reported outcomes in clinical cancer care: a Delphi study

Purpose

The aim of this study was to develop priority recommendations for the service level implementation of patient-reported outcomes (PROs) into clinical cancer care.

Methods

Development of draft guidance statements was informed by a literature review, the Knowledge to Action (KTA) implementation framework, and discussion with PRO experts and cancer survivors. A two-round modified Delphi survey with key stakeholders including cancer survivors, clinical and research experts, and Information Technology specialists was undertaken. Round 1 rated the importance of the statements and round 2 ranked statements in order of priority.

Results

Round 1 was completed by 70 participants with round 2 completed by 45 participants. Forty-seven statements were rated in round 2. In round 1, the highest agreement items (>90% agreement) included those that focused on the formation of strong stakeholder partnerships, ensuring ongoing communication within these partnerships, and the use of PROs for improvement and guidance in clinical care. Items ranked as the highest priorities in round 2 included assessment of current staff capabilities and service requirements, mapping of workflows and processes to enable collection, and using collected PROs to guide improved health outcomes.

Conclusions

This stakeholder consultation process has identified key priorities in PRO implementation into clinical cancer care that include clinical relevance, stakeholder engagement, communication, and integration within the existing processes and capabilities.

Implication for Cancer Survivors

Routine adoption of PRO collection by clinical cancer services requires multiple implementation steps; of highest priority is strong engagement and communication with key stakeholders including cancer survivors.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11764-021-01135-2.

The implementation of a decision aid for women with early-stage breast cancer considering contralateral prophylactic mastectomy: A pilot study

OBJECTIVE

Despite little survival benefit and potential for harm, contralateral prophylactic mastectomy (CPM) rates are increasing amongst early-stage breast cancer patients at low contralateral breast cancer risk. We developed a CPM decision aid (DA) and conducted a pilot implementation.

METHODS

Surgeons and oncologists recruited eligible patients considering CPM. Consenting patients received the DA, completed a questionnaire and participated in a semi-structured interview. Clinicians were interviewed at study close.

RESULTS

Eleven clinicians and 31 patients participated. Three themes emerged: perceived utility and impact of the DA, disagreement regarding timing of delivery and target population, and implementation strategies. Both women and clinicians found the DA valuable, indicating it confirmed rather than changed preferences. Women (all of whom raised CPM themselves), preferred offering the DA early in treatment discussions whilst clinicians favoured targeting women who enquired about CPM.

CONCLUSION

A DA about CPM is feasible and acceptable, but questions remain about the role of DAs in these types of decisions where one option has limited medical benefit.

PRACTICE IMPLICATIONS

Some women have a high need to make an informed choice about CPM. Tools to support this could include a DA with a clear recommendation against CPM and an explanation why.

Guiding the rational design of patient-centred drug trials in Cystic Fibrosis: A Delphi study

BACKGROUND

Making trials more patient-centred improves recruitment and retention, patient satisfaction and makes research accessible to a more representative population. We aimed to understand the factors that influence participation and engagement in clinical trials in cystic fibrosis (CF) trials to guide the rational design and delivery of patient-centred trials.

METHODS

We used a Delphi process, supported by extensive literature review and 3 workshops, to determine which factors stakeholders think exert significant influence in participation and engagement in CF trials. Panellists were recruited from across the UK and the study was administered online.

RESULTS

We had representation from 19 CF centres; 28 people with CF (pwCF), 26 parents and 30 healthcare professionals (HCPs). Panels were presented with a shortlist of 104 factors and asked which they thought influence participation and engagement in CF trials. After 3 iterations, 43 statements met consensus for pwCF, 48 for the parents and 69 for the HCPs.

CONCLUSIONS

We identified many targets to make trials more patient-centred. Whilst some require an overhaul of trial delivery, many are relatively easy to implement. We outline a list of 'dos and don'ts' for sponsors and research teams including: focus on good communication; recognise that lack of time is the greatest barrier to trial participation so minimise the frequency and length of visits; help participants fit trials around busy lives; remember trial participation can be a major life-event and support participants accordingly; and don't underestimate the impact of simple strategies e.g. on-site access to Wifi and cups of tea.

Collaborative development of course feedback with students for psyched up. Put more in, get more out

Introduction

PsychED Up is an extra-curricular course for 3^rd year medical students at King’s College London delivered by psychiatry trainees, senior students and actors. It focuses on the hidden medical curriculum, exploration of holistic care and communication skills.

Objectives

Develop a responsive and sustainable template for course evaluation Obtain rich and specific feedback across multiple domains which can be translated into course improvements Work collaboratively with former students Empower current students with the knowledge that their input is valuable

Methods

Embedded evaluation in start of term course development sessions to engage faculty in evaluation processes Faculty survey to determine what student feedback would be most useful Questionnaire finalised Collaborative design and refinement of questions, confirmed sub-sections and scope

Results

Revised questionnaire: - Included rationale at the start - Questions tailored to faculty development needs - Greater quantity of prompted questions - Specific questions for large group presentation, small group teaching, actors’ performances and students’ reflections - Quantitative ratings and open-space questions thoughtfully paired Reduced time between sessions and obtainment of feedback Quality and quantity of feedback: - High response rates: 32/30 (2 duplicates) mid-term, 29/30 end-of-term - High-quality filling of open-space feedback allowed consolidation of themes to improve the course

Conclusions

Co-designed questionnaire brought focus and organisation to questions leading to richer, more personalised responses for faculty More detailed reflections were attributed to better student understanding of the questionnaire rationale, and knowledge that they would aid course improvement Created a robust system for collecting long-term feedback for PsychED Up and will continue making iterative amendments

Cost-effectiveness of radioguided occult lesion localization using 125I seeds versus hookwire localization before breast-conserving surgery for non-palpable breast cancer

BACKGROUND

The aim was to determine the cost-effectiveness of radioguided occult lesion localization using 125I-labelled seeds (125I seeds) versus hookwire localization in terms of incremental cost per reoperation avoided for women with non-palpable breast cancer undergoing breast-conserving surgery.

METHODS

This study was based on a multicentre RCT with eight study sites comprising seven public hospitals and one private hospital. An Australian public health system perspective was taken. The primary effectiveness outcome for this study was reoperations avoided. Cost-effectiveness was expressed as an incremental cost-effectiveness ratio (ICER). One-way and probabilistic sensitivity analyses were used to explore uncertainty. The willingness to pay (additional cost of localization using 125I seeds justified by reoperation cost avoided) was set at the weighted, top-down cost of reoperation. Costs were in 2019 Australian dollars ($1 was equivalent to €0.62).

RESULTS

The reoperation rate was 13.9 (95 per cent confidence interval 10.7 to 18.0) per cent for the 125I seed group and 18.9 (14.8 to 23.8) per cent for the hookwire localization group. The ICER for 125I seed versus hookwire localization was $4474 per reoperation averted. The results were most sensitive to uncertainty around the probability of reoperation. Accounting for transition probability and cost uncertainty for 125I seed localization, there was a 77 per cent probability that using 125I seeds would be cost-effective, with a willingness to pay of $7693 per reoperation averted.

CONCLUSION

Radioguided occult lesion localization using 125I seeds is likely to be cost-effective, because the marginal (additional) cost compared with hookwire localization is less than the cost of reoperations avoided.

Single-use negative-pressure wound therapy versus conventional dressings for closed surgical incisions: systematic literature review and meta-analysis

Background

Surgical-site complications (SSCs) remain a significant cause of morbidity and mortality, particularly in high-risk patients. The aim of this study was to determine whether prophylactic use of a specific single-use negative-pressure wound therapy (sNPWT) device reduced the incidence of SSCs after closed surgical incisions compared with conventional dressings.

Methods

A systematic literature review was performed using MEDLINE, Embase and the Cochrane Library to identify articles published from January 2011 to August 2018. RCTs and observational studies comparing PICO™ sNPWT with conventional dressings, with at least 10 patients in each treatment arm, were included. Meta-analyses were performed to determine odds ratios (ORs) or mean differences (MDs), as appropriate. PRISMA guidelines were followed. The primary outcome was surgical-site infection (SSI). Secondary outcomes were other SSCs and hospital efficiencies. Risk of bias was assessed.

Results

Of 6197 citations screened, 29 studies enrolling 5614 patients were included in the review; all studies included patients with risk factors for SSCs. sNPWT reduced the number of SSIs (OR 0.37, 95 per cent c.i. 0.28 to 0.50; number needed to treat (NNT) 20). sNPWT reduced the odds of wound dehiscence (OR 0.70, 0.53 to 0.92; NNT 26), seroma (OR 0.23, 0.11 to 0.45; NNT 13) and necrosis (OR 0.11, 0.03 to 0.39; NNT 12). Mean length of hospital stay was shorter in patients who underwent sNPWT (MD −1.75, 95 per cent c.i. −2.69 to −0.81).

Conclusion

Use of the sNPWT device in patients with risk factors reduced the incidence of SSCs and the mean length of hospital stay.

MSTO1 mutations cause mtDNA depletion, manifesting as muscular dystrophy with cerebellar involvement

MSTO1 encodes a cytosolic mitochondrial fusion protein, misato homolog 1 or MSTO1. While the full genotype–phenotype spectrum remains to be explored, pathogenic variants in MSTO1 have recently been reported in a small number of patients presenting with a phenotype of cerebellar ataxia, congenital muscle involvement with histologic findings ranging from myopathic to dystrophic and pigmentary retinopathy. The proposed underlying pathogenic mechanism of MSTO1-related disease is suggestive of impaired mitochondrial fusion secondary to a loss of function of MSTO1. Disorders of mitochondrial fusion and fission have been shown to also lead to mitochondrial DNA (mtDNA) depletion, linking them to the mtDNA depletion syndromes, a clinically and genetically diverse class of mitochondrial diseases characterized by a reduction of cellular mtDNA content. However, the consequences of pathogenic variants in MSTO1 on mtDNA maintenance remain poorly understood. We present extensive phenotypic and genetic data from 12 independent families, including 15 new patients harbouring a broad array of bi-allelic MSTO1 pathogenic variants, and we provide functional characterization from seven MSTO1-related disease patient fibroblasts. Bi-allelic loss-of-function variants in MSTO1 manifest clinically with a remarkably consistent phenotype of childhood-onset muscular dystrophy, corticospinal tract dysfunction and early-onset non-progressive cerebellar atrophy. MSTO1 protein was not detectable in the cultured fibroblasts of all seven patients evaluated, suggesting that pathogenic variants result in a loss of protein expression and/or affect protein stability. Consistent with impaired mitochondrial fusion, mitochondrial networks in fibroblasts were found to be fragmented. Furthermore, all fibroblasts were found to have depletion of mtDNA ranging from 30 to 70% along with alterations to mtDNA nucleoids. Our data corroborate the role of MSTO1 as a mitochondrial fusion protein and highlight a previously unrecognized link to mtDNA regulation. As impaired mitochondrial fusion is a recognized cause of mtDNA depletion syndromes, this novel link to mtDNA depletion in patient fibroblasts suggests that MSTO1-deficiency should also be considered a mtDNA depletion syndrome. Thus, we provide mechanistic insight into the disease pathogenesis associated with MSTO1 mutations and further define the clinical spectrum and the natural history of MSTO1-related disease.

Evaluation of the BAX® System for Detection of Salmonella in Selected Foods: Collaborative Study

A multilaboratory study was conducted to compare the automated BAX® System to the standard cultural methods for detection of Salmonella in selected foods. Five food types—frankfurters, raw ground beef, mozzarella cheese, raw frozen tilapia fish, and orange juice—at 3 inoculation levels, were analyzed by each method. A sixth food type, raw ground chicken, was tested using 3 naturally contaminated lots. A total of 16 laboratories representing government and industry participated. In this study, 1386 samples were analyzed, of which 1188 were paired samples and 198 were unpaired samples. Of the 1188 paired samples, 461 were positive by both methods and 404 were negative by both methods. Thirty-seven samples were positive by the BAX System but negative by the standard reference method, and 11 samples were positive by standard cultural method and negative by the BAX System. Of the 198 unpaired samples, 106 were positive by the BAX System and 60 were positive by the standard cultural method. A Chi square analysis of each of the 6 food types, at the 3 inoculation levels tested, was performed. For all foods, the BAX System demonstrated results comparable to those of the standard reference methods based on the Chi square results.

Patient-Reported Outcome Measures Among Breast Cancer Survivors in Malaysia: A Comparative Study With Patients From High-Income Countries

Background: Patient-reported outcome measures (PROMs) are essential for identifying how patients perceive the outcomes of their cancer treatment, and is the ultimate success of cancer care. Although a growing number of studies have focused on PROMs in high income countries (HICs), outcomes relevant to patients in developing countries are less understood. Furthermore, the lack of standardization in PROMs makes it difficult to interpret these data for research or quality monitoring. Aim: In this study, we compared the results of PROM measures between patients in Malaysia, a middle income country, and those in HICs, using standard PROMs questionnaires. We also explored the differences in perceived importance of patient reported outcomes within the multiracial Malaysian cohort. Methods: Breast cancer patients (n=1063) were recruited in hospitals serving suburban areas of Malaysia. Of these, 969 patients were eligible for analysis. The surveys were conducted through face-to-face interviews (68%) or were self-administered (30%). An outcome was considered important if it was scored between 7-9 on a 9-point Likert scale. We compared PROMs scores between Malaysian patients and data previously collected from patients in HICs using logistic regression models, adjusting for demographic and clinical characteristics. A two-step cluster analysis was conducted to explore differences in the perceived importance of PROMs between clusters of Malaysian patients. Results: Compared with 1777 patients from HICs, Malaysian patients were less likely to rate overall and recurrence free survival, as well as emotional, cognitive, social and sexual functioning as very important outcomes. Interestingly, more Malaysian women reported that pain (50% vs. 39%), breast symptoms (51% vs. 35%), and major complications (60% vs. 44%) were very important outcomes ( P < 0.001). Compared with young, married Malaysian women, the cluster of older married women (mean age of 57 vs. 52), who were less likely to have received breast reconstructive surgery (8.6% vs. 16.8%), was more likely to rate sexual functioning (32.8% vs. 25.0%, P = 0.036), body image (63.9% vs. 42.4%, P < 0.001), and satisfaction with the breast (50.7% vs. 37.0%, P = 0.011) as very important outcomes. Conclusion: The differences in breast cancer patient needs between and within populations should be considered carefully to better clinician-patient relationship, patient care and satisfaction and assess the outcomes of our cancer care. Future research is needed to find suitable targeted interventions to identify and address the diverse needs of breast cancer patients in low and middle income countries.

Genetic characterisation of molecular targets in carcinoma of unknown primary

BACKGROUND

Carcinoma of unknown primary (CUP) is a metastatic epithelial malignancy in the absence of an identifiable primary tumour. Prognosis for patients with CUP is poor because treatment options are generally limited to broad spectrum chemotherapy. A shift towards personalised cancer management based on mutation profiling offers the possibility of new treatment paradigms. This study has explored whether actionable, oncogenic driver mutations are present in CUP that have potential to better inform treatment decisions.

METHODS

Carcinoma of unknown primary cases (n = 21) were selected and DNA was isolated from formalin-fixed paraffin embedded sections prior to amplification and sequencing. Two distinct yet complementary targeted gene panels were used to assess variants in up to 76 known cancer-related genes for the identification of biologically relevant and actionable mutations.

RESULTS

Variants were detected in 17/21 cases (81%) of which 11 (52%) were potentially actionable with drugs currently approved for use in known primary cancer types or undergoing clinical trials. The most common variants detected were in TP53 (47%), KRAS (12%), MET (12%) and MYC (12%). Differences at the molecular level were seen between common CUP histological subtypes. CUP adenocarcinomas and poorly differentiated carcinomas harboured the highest frequency of variants in genes involved in signal transduction pathways (e.g. MET, EGFR, HRAS, KRAS, and BRAF). In contrast, squamous cell carcinoma exhibited a higher frequency of variants in cell cycle control and DNA repair genes (e.g. TP53, CDKN2A and MLH1).

CONCLUSION

Taken together, mutations in biologically relevant genes were detected in the vast majority of CUP tumours, of which half provided a potentially novel treatment option not generally considered in CUP.

Systematic review of the impact of breast-conserving surgery on cancer outcomes of multiple ipsilateral breast cancers

Background

The clinical effectiveness of treating ipsilateral multifocal (MF) and multicentric (MC) breast cancers using breast‐conserving surgery (BCS) compared with the standard of mastectomy is uncertain. Inconsistencies relate to definitions, incidence, staging and intertumoral heterogeneity. The primary aim of this systematic review was to compare clinical outcomes after BCS versus mastectomy for MF and MC cancers, collectively defined as multiple ipsilateral breast cancers (MIBC).

Methods

Comprehensive electronic searches were undertaken to identify complete papers published in English between May 1988 and July 2015, primarily comparing clinical outcomes of BCS and mastectomy for MIBC. All study designs were included, and studies were appraised critically using the Newcastle–Ottawa Scale. The characteristics and results of identified studies were summarized.

Results

Twenty‐four retrospective studies were included in the review: 17 comparative studies and seven case series. They included 3537 women with MIBC undergoing BCS; breast cancers were defined as MF in 2677 women, MC in 292, and reported as MIBC in 568. Six studies evaluated MIBC treated by BCS or mastectomy, with locoregional recurrence (LRR) rates of 2–23 per cent after BCS at median follow‐up of 59·5 (i.q.r. 56–81) months. BCS and mastectomy showed apparently equivalent rates of LRR (risk ratio 0·94, 95 per cent c.i. 0·65 to 1·36). Thirteen studies compared BCS in women with MIBC versus those with unifocal cancers, reporting LRR rates of 2–40 per cent after BCS at a median follow‐up of 64 (i.q.r. 57–73) months. One high‐quality study reported 10‐year actuarial LRR rates of 5·5 per cent for BCS in 300 women versus 6·5 per cent for mastectomy among 887 women.

Conclusion

The available studies were mainly of moderate quality, historical and underpowered, with limited follow‐up and biased case selection favouring BCS rather than mastectomy for low‐risk patients. The evidence was inconclusive, weakening support for the St Gallen consensus and supporting a future randomized trial.

Abstract P6-12-01: Can exercise influence survival following breast cancer? Evidence from randomised, controlled trials

Background: The Exercise for Health (EfH) trials were randomized, controlled trials designed to evaluate an 8-month pragmatic, exercise intervention, commencing 6 weeks post-surgery for women with newly diagnosed breast cancer residing in urban- or rural/regional areas. Outcomes for these exploratory analyses were overall survival (OS), breast cancer-specific survival (BCS) and disease-free survival (DFS). Methods: Consenting urban-residing women (EfH 1, n=194) and rural/regional-residing women (EfH 2, n=143) were randomized to exercise or usual care. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for OS, BCS and DFS (exercise group, n=207, 65% urban women; usual care group, n=130, 46% urban women), with and without adjustment for prognostic factors including trial (urban/rural), age, body mass index, disease stage and presence of comorbidities. Further exploratory subgroup analyses were also conducted to assess whether effect on OS, BCS and DFS differed according to prognostic variables. Results: After a median follow-up of 8.3 years (IQR: 8.0-8.7 years) there were 11 (5.3%) deaths in the exercise group compared with 15 (11.5%) deaths in the usual care group (Table 1).

Table 1 Overall, breast cancer-specific and disease-free survival events by group allocation. All patientsUsual careExercise n=337n = 130n = 207 n (%)n (%)n (%)Breast cancer-related deaths20 (5.9)10 (7.7)10 (4.8)Non-breast cancer-related deaths6 (1.8)5 (3.8)1 (0.5)Overall survival events26 (7.7)15 (11.5)11 (5.3)Recurrence of breast cancer20 (5.9)8 (6.2)12 (5.8)Alive at follow-up9 (2.7)3 (2.3)6 (4.6)Deceased by follow-up11 (3.3)5 (3.1)6 (4.6)New primary breast cancer13 (3.9)5 (3.8)8 (3.9)Alive at follow-up13 (3.9)5 (3.8)8 (6.2)Deceased by follow-up0 (0.0)0 (0.0)0 (0.0)Disease-free survival events*48 (14.2)23 (17.7)25 (12.1)* Disease-free survival events include recurrence of breast cancer, new primary breast cancers, and all-cause deaths. Note that women who had recurrence and died before follow-up only count once towards disease-free survival events.

HRs for the exercise group were: OS: 0.45, 95% CI=0.20-0.96; p=0.04; BCS: 0.61, 95% CI=0.25-1.46, p=0.26; and DFS: 0.66, 95% CI=0.38-1.17; p=0.16 (adjusted analyses yielded similar results). With the exception of BCS for those with a body mass index &gt;30, all HRs for subgroup analyses favored exercise, with effect on OS for women of younger age (&lt;55), those with stage II+ disease, and those with 1+ comorbidity at baseline significant (p&lt;0.05). Effect of exercise on DFS was also significant (p&lt;0.05) for urban women. Conclusion: Findings suggest that an individually-prescribed and monitored exercise program integrated during and beyond treatment for breast cancer, and that was designed to cater for all women, irrespective of place of residence and access to health services, has clear potential to influence survival.

Citation Format: Hayes SC, Steele M, Spence R, Gordon L, Battistutta D, Bashford J, Pyke C, Saunders C, Eakin E. Can exercise influence survival following breast cancer? Evidence from randomised, controlled trials [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-12-01.

Exercise following breast cancer: exploratory survival analyses of two randomised, controlled trials

PURPOSE

The Exercise for Health trials were randomised, controlled trials designed to evaluate an 8-month pragmatic exercise intervention, commencing 6 weeks post-surgery for women with newly diagnosed breast cancer residing in urban or rural/regional Australia. For these exploratory analyses, the primary and secondary outcomes were overall survival (OS) and disease-free survival (DFS), respectively.

METHODS

Consenting urban- (n = 194) and rural/regional-residing women (n = 143) were randomised to exercise (intervention delivered face-to-face or by telephone) or usual care. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) for survival outcomes (exercise group, n = 207, 65% urban women; usual care group, n = 130, 46% urban women).

RESULTS

After a median follow-up of 8.3 years, there were 11 (5.3%) deaths in the exercise group compared with 15 (11.5%) deaths in the usual care group (OS HR for the exercise group: 0.45, 95% CI 0.20-0.96; p = 0.04). DFS events for the exercise versus usual care group were 25 (12.1%) and 23 (17.7%), respectively (HR: 0.66, 95% CI 0.38-1.17; p = 0.16). HRs for OS favoured exercise irrespective of age, body mass index, stage of disease, intervention compliance, and physical activity levels at 12 months post-diagnosis, although were stronger (p < 0.05) for younger women, women with stage II + disease, women with 1 + comorbidity at time of diagnosis, higher intervention compliance and for those who met national physical activity guidelines at 12 months post-diagnosis.

CONCLUSION

An exercise intervention delivered during and beyond treatment for breast cancer, and that was designed to cater for all women irrespective of place of residence and access to health services, has clear potential to benefit survival. Trial numbers: ACT RN: 012606000233527; ACT RN: 12609000809235.

Liver transplantation for "very early" intrahepatic cholangiocarcinoma: International retrospective study supporting a prospective assessment

The presence of an intrahepatic cholangiocarcinoma (iCCA) in a cirrhotic liver is a contraindication for liver transplantation in most centers worldwide. Recent investigations have shown that "very early" iCCA (single tumors ≤2 cm) may have acceptable results after liver transplantation. This study further evaluates this finding in a larger international multicenter cohort. The study group was composed of those patients who were transplanted for hepatocellular carcinoma or decompensated cirrhosis and found to have an iCCA at explant pathology. Patients were divided into those with "very early" iCCA and those with "advanced" disease (single tumor >2 cm or multifocal disease). Between January 2000 and December 2013, 81 patients were found to have an iCCA at explant; 33 had separate nodules of iCCA and hepatocellular carcinoma, and 48 had only iCCA (study group). Within the study group, 15/48 (31%) constituted the "very early" iCCA group and 33/48 (69%) the "advanced" group. There were no significant differences between groups in preoperative characteristics. At explant, the median size of the largest tumor was larger in the "advanced" group (3.1 [2.5-4.4] versus 1.6 [1.5-1.8]). After a median follow-up of 35 (13.5-76.4) months, the 1-year, 3-year, and 5-year cumulative risks of recurrence were, respectively, 7%, 18%, and 18% in the very early iCCA group versus 30%, 47%, and 61% in the advanced iCCA group, P = 0.01. The 1-year, 3-year, and 5-year actuarial survival rates were, respectively, 93%, 84%, and 65% in the very early iCCA group versus 79%, 50%, and 45% in the advanced iCCA group, P = 0.02.

CONCLUSION

Patients with cirrhosis and very early iCCA may become candidates for liver transplantation; a prospective multicenter clinical trial is needed to further confirm these results. (Hepatology 2016;64:1178-1188).

Observation versus late reintroduction of letrozole as adjuvant endocrine therapy for hormone receptor-positive breast cancer (ANZ0501 LATER): an open-label randomised, controlled trial

BACKGROUND

Despite the effectiveness of adjuvant endocrine therapy in preventing breast cancer recurrence, breast cancer events continue at a high rate for at least 10 years after completion of therapy.

PATIENTS AND METHODS

This randomised open label phase III trial recruited postmenopausal women from 29 Australian and New Zealand sites, with hormone receptor-positive early breast cancer, who had completed ≥4 years of endocrine therapy [aromatase inhibitor (AI), tamoxifen, ovarian suppression, or sequential combination] ≥1 year prior, to oral letrozole 2.5 mg daily for 5 years, or observation. Treatment allocation was by central computerised randomisation, stratified by institution, axillary node status and prior endocrine therapy. The primary outcome was invasive breast cancer events (new invasive primary, local, regional or distant recurrence, or contralateral breast cancer), analysed by intention to treat. The secondary outcomes were disease-free survival (DFS), overall survival, and safety.

RESULTS

Between 16 May 2007 and 14 March 2012, 181 patients were randomised to letrozole and 179 to observation (median age 64.3 years). Endocrine therapy was completed at a median of 2.6 years before randomisation, and 47.5% had tumours of >2 cm and/or node positive. At 3.9 years median follow-up (interquartile range 3.1-4.8), 2 patients assigned letrozole (1.1%) and 17 patients assigned observation (9.5%) had experienced an invasive breast cancer event (difference 8.4%, 95% confidence interval 3.8% to 13.0%, log-rank test P = 0.0004). Twenty-four patients (13.4%) in the observation and 14 (7.7%) in the letrozole arm experienced a DFS event (log-rank P = 0.067). Adverse events linked to oestrogen depletion, but not serious adverse events, were more common with letrozole.

CONCLUSION

These results should be considered exploratory, but lend weight to emerging data supporting longer duration endocrine therapy for hormone receptor-positive breast cancer, and offer insight into reintroduction of AI therapy.

CLINICAL TRIALS NUMBER

Australian New Zealand Clinical Trials Registry (www.anzctr.org.au), ACTRN12607000137493.

New Insights on COX-2 in Chronic Inflammation Driving Breast Cancer Growth and Metastasis

The medicinal use of aspirin stretches back to ancient times, before it was manufactured in its pure form in the late 19th century. Its accepted mechanistic target, cyclooxygenase (COX), was discovered in the 1970s and since this landmark discovery, the therapeutic application of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) has increased dramatically. The most significant benefits of NSAIDs are in conditions involving chronic inflammation (CI). Given the recognized role of CI in cancer development, the use of long-term NSAID treatment in the prevention of cancer is an enticing possibility. COX-2 is a key driver of CI, and here we review COX-2 expression as a predictor of survival in various cancer types, including breast. Obesity and post-partum involution are natural inflammatory states that are associated with increased breast cancer risk. We outline the COX-2 mediated mechanisms contributing to the growth of cancers. We dissect the cellular mechanism of epithelial-mesenchymal transition (EMT) and how COX-2 may induce this to facilitate tumor progression. Finally we examine the potential regulation of COX-2 by c-Myb, and the possible interplay between c-Myb/COX-2 in proliferation, and hypoxia inducible factor-1 alpha (HIF1α)/COX-2 in invasive pathways in breast cancer.