ORE identifies extreme expression effects enriched for rare variants

MOTIVATION

Non-coding rare variants (RVs) may contribute to Mendelian disorders but have been challenging to study due to small sample sizes, genetic heterogeneity and uncertainty about relevant non-coding features. Previous studies identified RVs associated with expression outliers, but varying outlier definitions were employed and no comprehensive open-source software was developed.

RESULTS

We developed Outlier-RV Enrichment (ORE) to identify biologically-meaningful non-coding RVs. We implemented ORE combining whole-genome sequencing and cardiac RNAseq from congenital heart defect patients from the Pediatric Cardiac Genomics Consortium and deceased adults from Genotype-Tissue Expression. Use of rank-based outliers maximized sensitivity while a most extreme outlier approach maximized specificity. Rarer variants had stronger associations, suggesting they are under negative selective pressure and providing a basis for investigating their contribution to Mendelian disorders.

AVAILABILITY AND IMPLEMENTATION

ORE, source code, and documentation are available at https://pypi.python.org/pypi/ore under the MIT license.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Cross-Canada differences in early-stage breast cancer treatment and acute-care use

Background

Chemotherapy has improved outcomes in early-stage breast cancer, but treatment practices vary, and use of acute care is common. We conducted a pan-Canadian study to describe treatment differences and the incidence of emergency department visits (edvs), edvs leading to hospitalization (edvhs), and direct hospitalizations (hs) during adjuvant chemotherapy.

Methods

The cohort consisted of women diagnosed with early-stage breast cancer (stages i-iii) during 2007-2012 in British Columbia, Manitoba, Ontario, or Nova Scotia who underwent curative surgery. Parallel provincial analyses were undertaken using linked clinical, registry, and administrative databases. The incidences of edvs, edvhs, and hs in the 6 months after treatment initiation were examined for patients treated with adjuvant chemotherapy.

Results

The cohort consisted of 50,224 patients. The proportion of patients who received chemotherapy varied by province, with Ontario having the highest proportion (46.4%), and Nova Scotia, the lowest proportion (38.0%). Age, stage, receptor status, comorbidities, and geographic location were associated with receipt of chemotherapy in all provinces. Ontario had the highest proportion of patients experiencing an edv (36.1%), but the lowest proportion experiencing h (6.4%). Conversely, British Columbia had the lowest proportion of patients experiencing an edv (16.0%), but the highest proportion experiencing h (26.7%). The proportion of patients having an edvh was similar across provinces (13.9%-16.8%). Geographic location was associated with edvs, edvhs, and hs in all provinces.

Conclusions

Intra- and inter-provincial differences in the use of chemotherapy and acute care were observed. Understanding variations in care can help to identify gaps and opportunities for improvement and shared learnings.

The role of scientific evidence in decisions to adopt complex innovations in cancer care settings: a multiple case study in Nova Scotia, Canada

Background

Health care delivery and outcomes can be improved by using innovations (i.e., new ideas, technologies, and practices) supported by scientific evidence. However, scientific evidence may not be the foremost factor in adoption decisions and is rarely sufficient. The objective of this study was to examine the role of scientific evidence in decisions to adopt complex innovations in cancer care.

Methods

Using an explanatory, multiple case study design, we examined the adoption of complex innovations in five purposively sampled cases in Nova Scotia, Canada. Data were collected via documents and key informant interviews. Data analysis involved an in-depth analysis of each case, followed by a cross-case analysis to develop theoretically informed, generalizable knowledge on the role of scientific evidence in innovation adoption that may be applied to similar settings and contexts.

Results

The analyses identified key concepts alongside important caveats and considerations. Key concepts were (1) scientific evidence underpinned the adoption process, (2) evidence from multiple sources informed decision-making, (3) decision-makers considered three key issues when making decisions, and (4) champions were essential to eventual adoption. Caveats and considerations related to the presence of urgent problems and short-term financial pressures and minimizing risk.

Conclusions

The findings revealed the different types of issues decision-makers consider while making these decisions and why different sources of evidence are needed in these processes. Future research should examine how different types of evidence are legitimized and why some types are prioritized over others.

Electronic supplementary material

The online version of this article (10.1186/s13012-019-0859-5) contains supplementary material, which is available to authorized users.

Patterns of cancer centre follow-up care for survivors of breast, colorectal, gynecologic, and prostate cancer

Background

Rising demand on cancer system resources, alongside mounting evidence that demonstrates the safety and acceptability of primary care-led follow-up care, has resulted in some cancer centres discharging patients back to primary care after treatment. At the same time, the ways in which routine cancer follow-up care is provided across Canada continue to vary widely. The objectives of the present study were to investigate patterns of routine follow-up care at a cancer centre for breast, colorectal, gynecologic, and prostate cancer survivors; factors associated with receipt of follow-up care at a cancer centre; and changes in follow-up care at a cancer centre over time.

Methods

We identified all people diagnosed in Nova Scotia with an invasive breast, colorectal, gynecologic, or prostate cancer between 1 January 2006 and 31 December 2013. We linked the resulting population-based dataset, at the patient level, to cancer centre or clinic data and to census data. We identified a nonmetastatic survivor cohort (n = 12,267) and developed decision rules to differentiate routine from non-routine visits during the follow-up care period (commencing 1 year after diagnosis). Descriptive statistics were computed to describe the patterns of routine follow-up care at a cancer centre. Negative binomial regression was used to examine factors associated with visits made and changes over time.

Results

Nearly half the survivors (48.4%) had at least 1 follow-up visit to the cancer centre, with variation by disease site (range: 30.2%-62.4%). Disease site and stage at diagnosis were associated with receipt of follow-up care at a cancer centre. For instance, compared with breast cancer survivors, survivors of gynecologic cancer had more visits [incidence rate ratio (irr): 1.48; 95% confidence interval (ci): 1.34 to 1.64], and survivors of colorectal cancer had fewer visits (irr: 0.45; 95% ci: 0.40 to 0.51). Year of diagnosis was associated with follow-up at a cancer centre, with each successive calendar year being associated with an 8% increase in visits made (irr: 1.08; 95% ci: 1.07 to 1.10).

Conclusions

Despite evidence that follow-up care can be effectively and safely delivered in primary care, and despite intensifying demands on oncology services, many survivors continue to receive routine follow-up care at a cancer centre.

Decision-making by surgeons about referral for adjuvant therapy for patients with non-small-cell lung, breast or colorectal cancer: a qualitative study

BACKGROUND

Because surgeons are the main gatekeepers to oncology services, understanding how they make decisions related to referral for adjuvant therapies is important to optimize referral rates and use of oncology services for patients with potentially curable disease. We examined decision-making by surgeons related to referral to oncology services for patients having undergone curative-intent surgery for non-small-cell lung, breast or colorectal cancer.

METHODS

We conducted a qualitative study, whose design was guided by the principles of grounded theory. Semi-structured interviews were held with 29 surgeons who performed non-small-cell lung, breast or colorectal cancer surgery in the province of Nova Scotia. Data were collected and analyzed concurrently. Analysis involved an inductive, grounded approach using constant comparative analysis. Data collection and analysis continued until theoretical saturation was reached.

RESULTS

Seven factors influenced the surgeons' decision-making related to referral to oncology services: indications and contraindications for therapy; patients' beliefs and preferences; a belief that oncologists are the experts; knowledge of local standards of care; consultation with oncology colleagues; navigating patient logistics (e.g., lodging, caregiving responsibilities, insurance coverage); and system resources and capacity.

INTERPRETATION

Our study's findings provide a novel understanding of how surgeons make decisions about oncology referral and point to potential areas for intervention to promote referral to oncology services for patients for whom adjuvant therapy is recommended.

Health System-Level Factors Influence the Implementation of Complex Innovations in Cancer Care

BACKGROUND

The movement of new knowledge and tools into healthcare settings continues to be a slow, complex and poorly understood process. In this paper, we present the system-level factors important to the implementation of synoptic reporting tools in two initiatives (or cases) in Nova Scotia, Canada.

METHODS

This study used case study methodology. Data were collected through interviews with key informants, document analysis, non-participant observation and tool use/examination. Analysis involved production of case histories, analysis of each case and a cross-case analysis.

RESULTS

The healthcare system's delivery and support structure, information technology infrastructure, policy environment and history of collaboration and inter-organizational relationships influenced tool implementation in the two cases.

CONCLUSIONS

The findings provide an in-depth, nuanced understanding of how healthcare system components can influence the implementation of a new tool in clinical practice.

Multi-level factors influence the implementation and use of complex innovations in cancer care: a multiple case study of synoptic reporting

BACKGROUND

The implementation of innovations (i.e., new tools and practices) in healthcare organizations remains a significant challenge. The objective of this study was to examine the key interpersonal, organizational, and system level factors that influenced the implementation and use of synoptic reporting tools in three specific areas of cancer care.

METHODS

Using case study methodology, we studied three cases in Nova Scotia, Canada, wherein synoptic reporting tools were implemented within clinical departments/programs. Synoptic reporting tools capture and present information about a medical or surgical procedure in a structured, checklist-like format and typically report only items critical for understanding the disease and subsequent impacts on patient care. Data were collected through semi-structured interviews with key informants, document analysis, nonparticipant observation, and tool use/examination. Analysis involved production of case histories, in-depth analysis of each case, and a cross-case analysis. Numerous techniques were used during the research design, data collection, and data analysis stages to increase the rigour of this study.

RESULTS

The analysis revealed five common factors that were particularly influential to implementation and use of synoptic reporting tools across the three cases: stakeholder involvement, managing the change process (e.g., building demand, communication, training and support), champions and respected colleagues, administrative and managerial support, and innovation attributes (e.g., complexity, compatibility with interests and values). The direction of influence (facilitating or impeding) of each of these factors differed across and within cases.

CONCLUSIONS

The findings demonstrate the importance of a multi-level contextual analysis to gaining both breadth and depth to our understanding of innovation implementation and use in health care. They also provide new insights into several important issues under-reported in the literature on moving innovations into healthcare practice, including the role of middle managers in implementation efforts and the importance of attending to the interpersonal aspects of implementation.

Bidirectional consultative process as a novel methodology to develop a pan-Canadian cancer quality initiative

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Background: To foster pan-Canadian quality improvement strategies in cancer diagnosis and treatment, a new publically funded opportunity was launched though a Request for Proposals (RFP). Methods to develop RFPs in the public health care sector are variable. To generate enthusiasm and ensure appropriateness and relevance of the RFP, a novel methodology was developed to refine and validate the focus of the RFP. Methods: An extensive multi-pronged bi-directional consultative process helped identify and engage with clinical experts, senior administrators, and other relevant stakeholders. In-person discussions with relevant stakeholders, an electronic stakeholder engagement survey, and two interactive electronic information sessions (Webinars) were included. The intent of the eBlast was to seek survey responses and also to build awareness of the upcoming opportunity. An eBlast engaged stakeholders and stakeholder networks for the electronic component of the bi-directional process. Secondary distribution encouraged wide-spread dissemination. The survey and recorded Webinar were publically posted online. Results: Approximately 30 in-person consultations occurred and the electronic survey and Webinar details were sent to approximate 1,000 individuals and external networks. 80 responses were received along with 76 Webinar attendees. Feedback was received from a representative cross-section of the Canadian quality community as measured by geographical distribution and discipline. There was general pan-Canadian agreement that the quality topic chosen was relevant and appropriate. Through this methodology refinements were made to finalize the organization and content of the RFP. Conclusions: When developing a national call for a publicly-funded quality improvement opportunity, it is imperative to ensure the topic considered is relevant, appropriate, and there is interest from stakeholders to apply. A bi-directional consultative process is a novel and economical method to ensure wide reaching engagement from relevant pan-Canadian stakeholders. This methodology can also be leveraged to refine and validate the final quality topic considered.

Clinical information available to oncologists in surgically treated rectal cancer: room to improve

INTRODUCTION

In rectal cancer, decisions about the use of adjuvant and neoadjuvant treatment rely on clinical information from a variety of sources. Currently, the quality and accuracy of the aggregate of this clinical information is unclear. The objectives of the present study were to evaluate the completeness and quality of clinical information available to oncologists managing rectal cancer.

METHODS

All patients diagnosed with rectal cancer in Nova Scotia between 2001 and 2005 were identified through the provincial cancer registry. The registry was linked to other administrative databases to obtain demographic, diagnostic, and treatment data. Patients undergoing radiation oncology consultation were identified, and a standardized review of the cancer centre chart was performed on a random sample, stratified by year.

RESULTS

For the 222 patients reviewed, the relevant endoscopy report was present in 113 cases (51%). The level of the tumour was documented in 75% of those reports, and colonoscopy completeness, in 81%. The relevant operative report was available in 192 cases (87%). Tumour level was described in 59% of those reports, and local extension, in 73%. Elements of total mesorectal excision were partially described in 97%. In pathology reports (10% of which were synoptic), we observed significant variability in the presence of important elements. Reporting of those elements was significantly better in the synoptic pathology reports.

CONCLUSIONS

Clinical information related to adjuvant and neoadjuvant therapy decision-making in rectal cancer is often not available or incomplete. A synoptic reporting system in endoscopy, surgery, and pathology could potentially be a beneficial tool in rectal cancer care.

Examining stage IIB survival in a population-based cohort of patients with colorectal cancer

BACKGROUND

In Nova Scotia, Canada, a previous study of colorectal cancer (CRC) cases diagnosed between January 1, 2001, and December 31, 2005, found that patients with stage IIB CRC had similar 5-year overall survival (OS) to those with stage IIIC cancer. This study sought to examine factors contributing to the observed stage IIB outcome, specifically nodal harvest, receipt of chemotherapy, and use of a new coding system to derive stage.

METHODS

The provincial cancer registry identified all CRC cases diagnosed during the study period and staged this cohort using the Collaborative Stage (CS) Data Collection System. All patients with stage II and III cancer in the cohort were examined. Kaplan-Meier (KM) survival curves compared 5-year OS for patients with stage IIB cancer based on the factors of interest, and compared patients with stage IIB cancer to those with stage IIA and III cancer.

RESULTS

OS for patients with stage IIB cancer (n = 187) was 44.7%, and differed depending on adequacy of nodal harvest (P = .005) and whether pathological or clinical/mixed evidence was used to derive stage (P = .013). Pathologically-staged patients with stage IIB cancer who had adequate nodal harvest had marginally improved OS compared to pathologically-staged patients who had inadequate nodal harvest (P = .07), and improved survival compared to patients with clinical/mixed stage (P = .004). Pathologically-staged patients with stage IIB cancer with adequate nodal harvest demonstrated similar 5-year OS to those with stage IIA and III cancer (P = .52 and P = .25, respectively). Cox proportional hazards models supported these findings.

CONCLUSIONS

The inclusion of clinical/mixed evidence into staging classification and, perhaps to a lesser extent, the adequacy of nodal harvest appear to contribute to the observed worse survival for patients with stage IIB versus stage III cancer.

How do surgeons decide to refer patients for adjuvant cancer treatment? Protocol for a qualitative study

BACKGROUND

Non-small cell lung cancer, breast cancer, and colorectal cancer are commonly diagnosed cancers in Canada. Patients diagnosed with early-stage non-small cell lung, breast, or colorectal cancer represent potentially curable populations. For these patients, surgery is the primary mode of treatment, with (neo)adjuvant therapies (e.g., chemotherapy, radiotherapy) recommended according to disease stage. Data from our research in Nova Scotia, as well as others', demonstrate that a substantial proportion of non-small cell lung cancer and colorectal cancer patients, for whom practice guidelines recommend (neo)adjuvant therapy, are not referred for an oncologist consultation. Conversely, surveillance data and clinical experience suggest that breast cancer patients have much higher referral rates. Since surgery is the primary treatment, the surgeon plays a major role in referring patients to oncologists. Thus, an improved understanding of how surgeons make decisions related to oncology services is important to developing strategies to optimize referral rates. Few studies have examined decision making for (neo)adjuvant therapy from the perspective of the cancer surgeon. This study will use qualitative methods to examine decision-making processes related to referral to oncology services for individuals diagnosed with potentially curable non-small cell lung, breast, or colorectal cancer.

METHODS

A qualitative study will be conducted, guided by the principles of grounded theory. The study design is informed by our ongoing research, as well as a model of access to health services. The method of data collection will be in-depth, semi structured interviews. We will attempt to recruit all lung, breast, and/or colorectal cancer surgeons in Nova Scotia (n ≈ 42), with the aim of interviewing a minimum of 34 surgeons. Interviews will be audiotaped and transcribed verbatim. Data will be collected and analyzed concurrently, with two investigators independently coding and analyzing the data. Analysis will involve an inductive, grounded approach using constant comparative analysis.

DISCUSSION

The primary outcomes will be (1) identification of the patient, surgeon, institutional, and health-system factors that influence surgeons' decisions to refer non-small cell lung, breast, and colorectal cancer patients to oncology services when consideration for (neo)adjuvant therapy is recommended and (2) identification of potential strategies that could optimize referral to oncology for appropriate individuals.

Exploring the interpersonal-, organization-, and system-level factors that influence the implementation and use of an innovation-synoptic reporting-in cancer care

Background

The dominant method of reporting findings from diagnostic and surgical procedures is the narrative report. In cancer care, this report inconsistently provides the information required to understand the cancer and make informed patient care decisions. Another method of reporting, the synoptic report, captures specific data items in a structured manner and contains only items critical for patient care. Research demonstrates that synoptic reports vastly improve the quality of reporting. However, synoptic reporting represents a complex innovation in cancer care, with implementation and use requiring fundamental shifts in physician behaviour and practice, and support from the organization and larger system. The objective of this study is to examine the key interpersonal, organizational, and system-level factors that influence the implementation and use of synoptic reporting in cancer care.

Methods

This study involves three initiatives in Nova Scotia, Canada, that have implemented synoptic reporting within their departments/programs. Case study methodology will be used to study these initiatives (the cases) in-depth, explore which factors were barriers or facilitators of implementation and use, examine relationships amongst factors, and uncover which factors appear to be similar and distinct across cases. The cases were selected as they converge and differ with respect to factors that are likely to influence the implementation and use of an innovation in practice. Data will be collected through in-depth interviews, document analysis, observation of training sessions, and examination/use of the synoptic reporting tools. An audit will be performed to determine/quantify use. Analysis will involve production of a case record/history for each case, in-depth analysis of each case, and cross-case analysis, where findings will be compared and contrasted across cases to develop theoretically informed, generalisable knowledge that can be applied to other settings/contexts. Ethical approval was granted for this study.

Discussion

This study will contribute to our knowledge base on the multi-level factors, and the relationships amongst factors in specific contexts, that influence implementation and use of innovations such as synoptic reporting in healthcare. Such knowledge is critical to improving our understanding of implementation processes in clinical settings, and to helping researchers, clinicians, and managers/administrators develop and implement ways to more effectively integrate innovations into routine clinical care.

Evaluating survivorship care plans: results of a randomized, clinical trial of patients with breast cancer

PURPOSE

An Institute of Medicine report recommends that patients with cancer receive a survivorship care plan (SCP). The trial objective was to determine if an SCP for breast cancer survivors improves patient-reported outcomes.

PATIENTS AND METHODS

Women with early-stage breast cancer who completed primary treatment at least 3 months previously were eligible. Consenting patients were allocated within two strata: less than 24 months and ≥ 24 months since diagnosis. All patients were transferred to their own primary care physician (PCP) for follow-up. In addition to a discharge visit, the intervention group received an SCP, which was reviewed during a 30-minute educational session with a nurse, and their PCP received the SCP and guideline on follow-up. The primary outcome was cancer-related distress at 12 months, assessed by the Impact of Event Scale (IES). Secondary outcomes included quality of life, patient satisfaction, continuity/coordination of care, and health service measures.

RESULTS

Overall, 408 survivors were enrolled through nine tertiary cancer centers. There were no differences between groups on cancer-related distress or on any of the patient-reported secondary outcomes, and there were no differences when the two strata were analyzed separately. More patients in the intervention than control group correctly identify their PCP as primarily responsible for follow-up (98.7% v 89.1%; difference, 9.6%; 95% CI, 3.9 to 15.9; P = .005).

CONCLUSION

The results do not support the hypothesis that SCPs are beneficial for improving patient-reported outcomes. Transferring follow-up to PCPs is considered an important strategy to meet the demand for scarce oncology resources. SCPs were no better than a standard discharge visit with the oncologist to facilitate transfer.

Improving nodal harvest in colorectal cancer: so what?

BACKGROUND

Adequate nodal harvest (≥12 lymph nodes) in colorectal cancer has been shown to optimize staging and has been proposed as a quality indicator of colorectal cancer care. We previously demonstrated a population-based improvement in adequate nodal harvest over time, particularly with the use of an audit and feedback strategy. The goal of this current study is to evaluate the impact of improved adequate nodal harvest on 3 relevant clinical outcomes: node positivity rate, use of adjuvant chemotherapy, and survival.

METHODS

This current population-based study included all patients undergoing resection for primary stage I-III colorectal cancer in Nova Scotia, Canada, from January 1, 2001 to December 31, 2005. Linkage of the provincial cancer registry with other administrative databases (hospital discharge data, physician claims data, and national census data) provided clinical, demographic, diagnostic, treatment event, and survival data. The association between increase in adequate node harvest and relevant clinical outcomes was examined for all patients and in a subgroup analysis of patients who received care in a health district that used audit and feedback to improve nodal harvest.

RESULTS

Among the 2,250 patients, the median nodal harvest was 8, and the overall node positive rate was 35.9%. Despite significant improvement in the proportion of patients undergoing adequate nodal harvest over time (P<.0001), no significant change was observed in the node positivity rate (P=.51), proportion of patients undergoing adjuvant chemotherapy (P=.83), or survival (P=.25). In the subgroup analysis confined to patients where audit and feedback was used to improve nodal harvest rates, clinical outcomes were not improved.

CONCLUSIONS

Although improvements in the rate of adequate nodal harvest did occur over time, no corresponding meaningful improvement in clinical outcomes was noted. Given the need that quality indicators not only be associated with outcome, but also that outcome improves as such indicators are optimized, this study questions the inclusion of a nodal harvest≥12 lymph nodes as a quality indicator of colorectal cancer care.

Quantifying limitations in chemotherapy data in administrative health databases: implications for measuring the quality of colorectal cancer care

Reliable chemotherapy data are critical to evaluate the quality of care for patients with colorectal cancer who are treated with curative intent. In Canada, limitations in the availability and completeness of chemotherapy data exist in many administrative health databases. In this paper, we discuss these limitations and present findings from a chart review in Nova Scotia that quantifies the completeness of chemotherapy capture in existing databases. The results demonstrate that even basic information on cancer treatment in administrative databases can be insufficient to perform the types of analyses that most decision-makers require for quality-of-care measurement.

The impact of audit and feedback on nodal harvest in colorectal cancer

Background

Adequate nodal harvest (≥ 12 lymph nodes) in colorectal cancer has been shown to optimize staging and proposed as a quality indicator of colorectal cancer care. An audit within a single health district in Nova Scotia, Canada presented and published in 2002, revealed that adequate nodal harvest occurred in only 22% of patients. The goal of this current study was to identify factors associated with adequate nodal harvest, and specifically to examine the impact of the audit and feedback strategy on nodal harvest.

Methods

This population-based study included all patients undergoing resection for primary colorectal cancer in Nova Scotia, Canada, from 01 January 2001 to 31 December 2005. Linkage of the provincial cancer registry with other databases (hospital discharge, physician claims data, and national census data) provided clinicodemographic, diagnostic, and treatment-event data. Factors associated with adequate nodal harvest were examined using multivariate logistic regression. The specific interaction between year and health district was examined to identify any potential effect of dissemination of the previously-performed audit.

Results

Among the 2,322 patients, the median nodal harvest was 8; overall, 719 (31%) had an adequate nodal harvest. On multivariate analysis, audited health district (p < 0.0001), year (p < 0.0001), younger age (p < 0.0001), non-emergent surgery (p < 0.0001), more advanced stage (p = 0.008), and previous cancer history (p = 0.03) were associated with an increased likelihood of an adequate nodal harvest. Interaction between year and audited health district was identified (p = 0.006) such that the increase in adequate nodal harvest over time was significantly greater in the audited health district.

Conclusions

Improvements in colorectal cancer nodal harvest did occur over time. A published audit demonstrating suboptimal nodal harvest appeared to be an effective knowledge translation tool, though more so for the audited health district, suggesting a potentially beneficial effect of audit and feedback strategies.

Reflections on knowledge brokering within a multidisciplinary research team

Knowledge brokering (KB) may be one approach of helping researchers and decision makers effectively communicate their needs and abilities, and move toward increased use of evidence in health care. A multidisciplinary research team in Nova Scotia, Canada, has created a dedicated KB position with the goal of improving access to quality colorectal cancer care. The purpose of this paper is to provide an in-progress perspective on KB within this large research team. A KB position ("knowledge broker") was created to perform two primary tasks: (1) facilitate ongoing communication among team members; and (2) develop and maintain collaborations between researchers and decision makers to establish partnerships for the transfer and use of research findings. In this article, we discuss our KB model and its implementation, describe the broker's functions and activities, and present preliminary outcomes. The primary functions of the KB position have included: sustaining team members' engagement; harnessing members' expertise and sharing it with others; developing and maintaining communication tools/strategies; and establishing collaborations between team members and other stakeholders working in cancer care. The broker has facilitated an integrated knowledge translation approach to research conduct and led to the development of new collaborations with external stakeholders and other cancer/health services researchers. KB roles will undoubtedly differ across contexts. However, descriptive assessments can help others determine whether such an approach could be valuable for their research programs and, if so, what to expect during the process.

Regulation of CDX2 expression in esophageal adenocarcinoma

Reflux of acidic gastric contents and bile acids into the lower esophagus has been identified to have a central role in esophageal malignancy and is reported to upregulate caudal-related homologue 2 (CDX2), a regulatory gene involved in embryonic development and axial patterning of the alimentary tract. The aim of this study was to characterize the expression of CDX2 in a well-defined series of human esophageal tissues, comprising reflux-induced esophagitis, premalignant Barrett esophagus (BE), and primary esophageal adenocarcinoma (EADC). To explore potential molecular regulatory mechanisms, we also studied the expression of beta-catenin, SOX9, and CDX2 promoter methylation in esophageal tissues, in addition to the effect of bile acids and nitric oxide (NO) on CDX2 expression in the normal human esophageal cell line Het1A. Relative to matched normal esophageal epithelia, CDX2 was overexpressed in esophagitis (37% for RNA; cytoplasmic immunoreactivity in 48% of tissues), a high proportion (91%) of BE tissues, and in EADC (57% for RNA; cell nuclear immunopositivity in 80%). An association with beta-catenin expression was seen, but not with SOX9 or CDX2 promoter methylation. In Het1A cells, CDX2 was upregulated following exposure to bile acids and NO, alone and in combination. These results further implicate CDX2 and beta-catenin in the molecular pathogenesis of human EADC. The observed synergistic effect of NO on the efficacy of bile acid-induction of CDX2 suggests a novel role for NO in modulating the development of the Barrett phenotype and esophageal adenocarcinogenesis.

A polymorphic variant of the insulin-like growth factor type I receptor gene modifies risk of obesity for esophageal adenocarcinoma

BACKGROUND

To investigate potential biologic mechanisms underlying the association between obesity and risk for esophageal adenocarcinoma (EADC), we studied the frequency of a common polymorphism of the insulin-like growth factor I receptor (IGF-IR) gene in patients with either gastroesophageal reflux disease (GERD), premalignant Barrett esophagus (BE) and or invasive EADC.

METHODS

Using a well characterized series of 431 individuals enrolled in a case-control study, we studied the frequency of the IGF-IR gene polymorphism, G1013A.

RESULTS

On multivariate analysis controlling for age and gender, in comparison to asymptomatic controls, obese individuals with the polymorphic A-variant (G/A, A/A) were found to have significantly increased risk for EADC (OR 4.81; 95%CI 1.09-21.15), whereas obese individuals with the G/G variant were not at statistically significant increased risk (OR 2.69; 95%CI 0.41-17.62). Similarly, compared to asymptomatic controls, only obese individuals with the A-variant (G/A, A/A) were at increased risk for BE (OR 3.11; 95%CI 1.12-8.63), while obese individuals with the G/G variant were not at increased risk for BE (OR 2.91; 95%CI 0.69-12.15).

CONCLUSION

We conclude that the common IGF-IR gene polymorphism G1013A modulates the risk of obesity for EADC, an effect most likely mediated by altered the receptor function by influencing gene transcription or mRNA stability. These findings further implicate the insulin-like growth factor axis in the molecular pathogenesis of EADC, and represent a plausible mechanistic link underlying the association between obesity and malignancy.

A phase II experience with neoadjuvant irinotecan (CPT-11), 5-fluorouracil (5-FU) and leucovorin (LV) for colorectal liver metastases

BACKGROUND

Chemotherapy may improve survival in patients undergoing resection of colorectal liver metastases (CLM). Neoadjuvant chemotherapy may help identify patients with occult extrahepatic disease (averting unnecessary metastasectomy), and it provides in vivo chemosensitivity data.

METHODS

A phase II trial was initiated in which patients with resectable CLM received CPT-11, 5-FU and LV for 12 weeks. Metastasectomy was performed unless extrahepatic disease appeared. Postoperatively, patients with stable or responsive disease received the same regimen for 12 weeks. Patients with progressive disease received either second-line chemotherapy or best supportive care. The primary endpoint was disease-free survival (DFS); secondary endpoints included overall survival (OS) and safety.

RESULTS

35 patients were accrued. During preoperative chemotherapy, 16 patients (46%) had grade 3/4 toxicities. Resection was not possible in 5 patients. One patient died of arrhythmia following surgery, and 1 patient had transient liver failure. During the postoperative treatment phase, 12 patients (55%) had grade 3/4 toxicities. Deep venous thrombosis (DVT) occurred in 11 patients (34%) at various times during treatment. Of those who underwent resection, median DFS was 23.0 mo. and median OS has not been reached. The overall survival from time of diagnosis of liver metastases was 51.6 mo for the entire cohort.

CONCLUSION

A short course of chemotherapy prior to hepatic metastasectomy may serve to select candidates best suited for resection and it may also direct postoperative systemic treatment. Given the significant incidence of DVT, alternative systemic neoadjuvant regimens should be investigated, particularly those that avoid the use of a central venous line.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00168155.

Inducible nitric oxide synthase, nitrotyrosine and p53 mutations in the molecular pathogenesis of Barrett's esophagus and esophageal adenocarcinoma

Nitric oxide (NO) has been implicated as a potential causative factor for endogenous p53 mutations in gastrointestinal malignancy. To investigate the role of NO in esophageal adenocarcinoma (EADC), we studied patterns of p53 mutations, expression of inducible nitric oxide synthase (iNOS) and the tissue accumulation of nitrotyrosine (NTS), a stable reaction product of NO and a marker for cellular protein damage, in human premalignant and malignant esophageal epithelia. Tissues were obtained from patients with gastroesophageal reflux disease (GERD)-induced esophagitis (n = 76), Barrett's esophagus (BE; n = 119) and primary EADC (n = 54). DNA sequencing was used to characterize p53 mutations, RT-PCR to study iNOS mRNA expression, and immunohistochemistry to study NTS. Relative to self-matched normal epithelia, a progressive increase in iNOS mRNA expression was seen in GERD (30%; 23/76), BE (48%; 57/119), and EADC (63%; 34/54) tissues (P < 0.001). Among patients with EADC, elevated levels of NTS immunoreactivity were more frequent in tumors with p53 mutations (11/21; 52%) compared with tumors with wild-type p53 (9/33; 27%; P = 0.063), and specifically in tumors with p53 mutations at CpG dinucleotides (10/12; 83%) compared with non-CpG p53 mutations (1/9; 11%; P = 0.008). The increasing frequency of iNOS (mRNA) overexpression in GERD, BE and EADC supports the hypothesis that an active inflammatory process, most likely a consequence of GERD, underlies molecular progression to EADC. The highly significant association between NTS, reflecting chronic NO-induced cellular protein damage, and endogenous p53 mutations at CpG dinucleotides, provides further evidence for a molecular link between chronic inflammation and esophageal malignancy.

Selective cyclooxygenase-2 inhibition suppresses basic fibroblast growth factor expression in human esophageal adenocarcinoma

Inhibition of cyclooxygenase (COX)-2 is reported to suppress growth and induce apoptosis in human esophageal adenocarcinoma (EADC) cells, although the precise biologic mechanism is unclear. In this study we tested the hypothesis that the antitumor activity of COX-2 inhibitors may involve modulation of basic fibroblast growth factor (FGF-2), which is overexpressed in EADC. We evaluated the effects of NS-398, a selective COX-2 inhibitor, on FGF-2 expression and proliferation of EADC cell lines that express COX-2 and those that do not. We also correlated COX-2 and FGF-2 expression with clinico-pathologic findings and outcome in a well-characterized series of surgically resected EADC tissues. Seg-1 cells robustly expressed COX-2 and FGF-2, whereas Bic-1 cells expressed neither transcript. FGF-2 was reduced to undetectable levels in Seg-1 cells following NS-398 treatment, but increased within 4 h of drug removal. NS-398 significantly inhibited the growth of Seg-1 cells, and this effect was ameliorated by addition of exogenous FGF-2. In contrast, NS-398 had no effect on Bic-1 cell proliferation and FGF-2 alone had no effect on proliferation of either cell line. NS-398, or a neutralizing anti-FGF-2 antibody, induced apoptosis in Seg-1 cells, and these effects were inhibited by addition of exogenous FGF-2. COX-2 protein was strongly expressed in 46% (10/22) of EADCs, and was associated with a trend towards reduced disease-free survival. These findings indicate that the antitumor effects of COX-2 inhibition in EADC cells may be mediated via suppression of FGF-2, and that COX-2 may be a clinically relevant molecular marker in the management of human EADC.

Alternative splicing of the FGF antisense gene: differential subcellular localization in human tissues and esophageal adenocarcinoma

Overexpression of FGF-2 is associated with tumor recurrence and reduced survival after surgical resection of esophageal cancer, and these risks are reduced in tumors co-expressing the FGF antisense (FGF-AS) RNA. The aim of this study was to characterize the expression of alternatively spliced FGF-AS transcripts and encoded nudix-motif proteins in normal human tissues and in esophageal adenocarcinoma, and to correlate their expression with clinicopathologic findings and outcome. Three alternatively spliced FGF-AS transcripts encoding GFG/NUDT6 isoforms with distinct N termini were detected in various human tissues including esophageal adenocarcinoma. Expression of each isoform as a fusion protein with enhanced green fluorescent protein revealed differential subcellular trafficking: hGFGa is localized to mitochondria by an N-terminal targeting sequence (MTS), whereas hGFGb and hGFGc were localized in the cytoplasm and nucleus. Mutation/deletion analysis confirmed that the predicted MTS was necessary and sufficient for mitochondrial compartmentalization. The predominant FGF-AS mRNA expressed in esophageal tumors was splice variant b. GFG immunoreactivity was detected in the cytoplasm of all esophageal adenocarcinomas and in 88% of tumor cell nuclei. Although we found a trend towards reduced disease-free survival in patients with FGF-2 overexpressing esophageal adenocarcinomas, significantly worse disease-free survival was noted among patients whose tumors did not also overexpress the FGF-AS b isoform (p = 0.03). Tetracycline-inducible FGF-AS b expression in stably transfected human Seg-1 esophageal adenocarcinoma cells resulted in a significant suppression of steady state FGF-2 mRNA content and cell proliferation. Our data implicate the FGF-AS b isoform in modulation of FGF-2 expression and clinical outcome in esophageal adenocarcinoma.

Factors influencing waiting times for elective laparoscopic cholecystectomy

INTRODUCTION

Health Canada states that waiting list information and management systems in Canada are woefully inadequate, especially for elective surgical procedures. Understanding the reasons for waiting is paramount to achieving fairness and equity. The objective of this study was to examine the impact of demographic and clinical factors and surgeon volume on waiting times for laparoscopic cholecystectomy (LC).

METHODS

We comprehensively applied a wait-list database for all surgical procedures across a division of general surgery and performed a chart review of all patients undergoing LC in 2002 to collect additional demographic and clinical data. We excluded patients undergoing LC on an emergent basis or as a secondary procedure. For each patient, we calculated 2 time intervals: time from the receipt of consult to the surgical consult (interval A) and time from the surgical consult to the LC (interval B). Surgeons were categorized a priori into low- and high-volume groups, based on the median number of procedures they had performed. All analyses examining waiting times were performed with nonparametric methods.

RESULTS

The study cohort included 294 patients; most (94.6%) underwent LC for biliary colic. The median waiting times for interval A and interval B were 22 days and 50 days, respectively. No associations were identified between any of the examined waiting times, sex, diagnosis or Charlston Comorbidity Index. High surgeon volume was associated with longer waiting times for interval A (median 26 v. 19 d; p=0.04) and interval B (median 58 v. 35 d; p=0.003) and was also associated with a greater number of episodes of biliary colic (2.7 v. 2.0; p=0.03).

CONCLUSION

There is significant variability in specific waiting times for LC, which appears to be associated with surgeon volume. Better prioritization of patients undergoing nonemergent LC is required to improve patient care.

Emergency room presentation of colorectal cancer: a consecutive cohort study

BACKGROUND

Emergency room presentation (ERP) in colorectal cancer (CRC) is associated with worse cancer-related outcomes. The goal of this study was to determine the frequency of ERP and identify factors associated with ERP of CRC.

METHODS

We performed a prospective consecutive cohort study of all patients undergoing resection for CRC from 02/2002 to 02/2004. Standardized data collection involved hospital record review, patient interview, and prospective follow-up. ERP was defined as the diagnosis and/or surgical treatment of CRC as a result of presentation to the emergency department.

RESULTS

Of the 455 patients in the study 108 (24%) had ERP. Presentation of those with ERP was obstruction in 46 (43%), bleeding/anemia in 35 (32%), pain in 25 (23%), and other (2%). The ERP cohort was older (mean age 70.8 vs. 67.0 years, P = 0.005). ERP was more common amongst females (29.7 vs. 18.2%, P = 0.004) and obesity appears to be associated with increased rates of ERP. ERP of CRC was associated with more advanced TNM stage. The ERP cohort had longer length of stay in hospital (median 10 vs. 8 days respectively, P < 0.001). Peri-operative mortality was higher in ERP patients (7.4 vs. 2.3%, P = 0.03).

CONCLUSIONS

ERP in CRC was not infrequent and appeared to be associated with female gender and weight. The known negative prognostic impact of ERP, combined with the increased peri-operative mortality and length of stay, would suggest a potential benefit to targeted strategies aimed at reducing the use of the emergency room in the diagnosis and treatment of CRC.

Genetic polymorphisms of microsomal epoxide hydroxylase and glutathione S-transferases M1, T1 and P1, interactions with smoking, and risk for esophageal (Barrett) adenocarcinoma

BACKGROUND

The aim of this case-control study was to test the hypothesis that polymorphisms of the microsomal epoxide hydroxylase (mEH) and glutathione S-transferase (GST) genes modulate the susceptibility to esophageal adenocarcinoma (EADC) associated with smoking.

METHODS

Cases included patients with gastroesophageal reflux disease (GERD) (n=126), Barrett esophagus (BE) (n=125), and EADC (n=56); controls comprised 95 strictly asymptomatic individuals. Genomic DNA was extracted from blood samples, and PCR-based assays were used to genotype mEH (slow allele, fast allele, predicted activity) and GSTM1, GSTT1 and GSTP1. Logistic regression was used to study associations between smoking and genotype, adjusting for age, gender and alcohol consumption.

RESULTS

Relative to asymptomatic controls, no significant differences were found for the distribution of mEH and GST polymorphic variants in cases with GERD, BE or EADC. Smoking was a risk factor for EADC, especially when cigarette exposure was greater than 30 pack-years (adjusted odds ratio [OR] 6.11, 95% confidence interval [CI] 2.2-17.32; P=0.001). The strong association between smoking and EADC was seen preferentially in patients with the active allele of either GSTM1 (OR 7.9, 95% CI 1.14-54.76; P=0.003) or GSTT1 (OR 3.2, 95% CI 1.23-8.35; P=0.004).

CONCLUSIONS

Cigarette smoking is an independent risk factor for EADC, and in particular for heavy smokers. The strong statistical association between smoking and risk for EADC in individuals with the active allele of either GSTM1 or GSTT1 may have potential clinical application in endoscopic surveillance programs to identify individuals with BE at increased risk for progression to EADC.

Obesity and lifestyle risk factors for gastroesophageal reflux disease, Barrett esophagus and esophageal adenocarcinoma

The aim of this study was to examine the association of obesity with esophageal adenocarcinoma, and with the precursor lesions Barrett esophagus and gastroesophageal reflux disease (GERD). This case-control study included cases with GERD (n = 142), Barrett esophagus (n = 130), and esophageal adenocarcinoma (n = 57). Controls comprised 102 asymptomatic individuals. Using logistic regression methods, we compared obesity rates between cases and controls adjusting for differences in age, gender, and lifestyle risk factors. Relative to normal weight, obese individuals were at increased risk for esophageal adenocarcinoma (Odds Ratio [OR] 4.67, 95% Confidence Interval [CI] 1.27-17.9). Diets high in vitamin C were associated with a lower risk for GERD (OR 0.40, 95% CI 0.19-0.87), Barrett esophagus (OR 0.44, 95% CI 0.20-0.98), and esophageal adenocarcinoma (OR 0.21, 95% CI 0.06-0.77). For the more established risk factors, we confirmed that smoking was a significant risk factor for esophageal adenocarcinoma, and that increased liquor consumption was associated with GERD and Barrett esophagus. In light of the current obesity epidemic, esophageal adenocarcinoma incidence rates are expected to continue to increase. Successful promotion of healthy body weight and diets high in vitamin C may substantially reduce the incidence of this disease.

Basic fibroblast growth factor (FGF-2) overexpression is a risk factor for esophageal cancer recurrence and reduced survival, which is ameliorated by coexpression of the FGF-2 antisense gene

PURPOSE

The basic fibroblast growth factor (FGF-2) gene is bidirectionally transcribed to generate overlapping sense and antisense (FGF-AS) mRNAs. FGF-AS has been implicated in the post-transcriptional regulation of FGF-2 expression. The aim of this study was to characterize FGF-2 and FGF-AS in esophageal cancer and to correlate their expression with clinicopathologic findings and outcome.

EXPERIMENTAL DESIGN

Reverse transcription-PCR was used to study FGF-2 and FGF-AS mRNA expression (normalized to glyceraldehyde-3-phosphate dehydrogenase) in 48 esophageal cancers relative to matched histologically normal esophageal epithelia (internal control). We used Cox proportional hazards analysis to calculate hazard ratios for recurrence and survival of patients with underexpression relative to the overexpression of FGF-2 and/or FGF-AS.

RESULTS

Overexpression of FGF-2 mRNA, by comparison with tumors underexpressing FGF-2, was associated with significantly increased risk for tumor recurrence (hazard ratio, 3.80; 95% confidence interval, 1.64-8.76) and reduced overall survival (hazard ratio, 2.11; 95% confidence interval, 1.0-4.58). When the effects of FGF-2 and FGF-AS were considered simultaneously, the association of FGF-2 mRNA overexpression with recurrence and mortality was even more pronounced, whereas FGF-AS mRNA overexpression was associated with reduced risk for recurrence and improved survival.

CONCLUSIONS

Overexpression of FGF-2 mRNA is associated with tumor recurrence and reduced survival after surgical resection of esophageal cancer and that these risks are reduced in tumors coexpressing the FGF-AS mRNA. These data support the hypothesis that FGF-AS is a novel tumor suppressor that modulates the effect of FGF-2 expression and may have potential clinical application to the development of novel therapeutic strategies.

Effect of obesity on presentation of breast cancer

BACKGROUND

Obesity has been shown to be associated with reduced survival in patients with invasive breast cancer (IBC), although the mechanisms for this finding are unclear. The objective of this study was to examine the effect of obesity on the presentation and pathologic staging of IBC.

METHODS

From February 15, 2002, to February 15, 2004, all patients undergoing surgery for primary IBC at two institutions were enrolled in a prospective cohort study. National Institutes of Health criteria were used to categorize patients: normal or underweight (NW; body mass index <25 kg/m(2)), overweight (OW; body mass index 25-29.9 kg/m(2)), and obese or severely obese (OB; body mass index > or =30 kg/m(2)). Presentation and pathologic factors were then compared among groups.

RESULTS

The study cohort consisted of 519 patients; 166 (32%) were NW, 177 (34%) were OW, and 176 (34%) were OB. OW (46%) and OB (39%) patients were more likely to be diagnosed with IBC via screening mammography compared with NW (31%) patients (P = .01), although no differences were found between groups with respect to previous use of screening mammography. Aggressive pathologic features, including lymph node metastases, advanced tumor-node-metastasis stage, and grade were found more commonly among OB patients.

CONCLUSIONS

OW and OB patients were more likely to receive a diagnosis via screening mammography, thus suggesting that mammography may play a more important role in OW and OB patients. Despite this, OB patients presented with larger, more advanced tumors; this may help to explain obesity-associated survival differences in IBC patients. This is important information given the prevalence of obesity in North America.

Retroperitoneal sarcoma

BACKGROUND

No population-based studies of retroperitoneal sarcoma (RPS) have been conducted, and the use and timing of adjuvant radiotherapy for RPS is controversial. The objective of this study was to examine the incidence and treatment of RPS, specifically regarding the use of adjuvant radiotherapy.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to evaluate the incidence of RPS over a 29-year period (1973-2001). The rate of surgery, the rate and timing of adjuvant radiotherapy, and the influence of demographic factors on treatment were evaluated.

RESULTS

A total of 2348 cases of RPS were identified. The mean annual incidence of RPS was 2.7 cases per 10(6) persons and did not change significantly over time (2.6 in 1973 vs. 2.8 in 2001; P = .92). Most patients (1654; 70.4%) underwent surgical resection. Radiotherapy was used in 428 patients (25.9%) who underwent surgery; radiation was given postoperatively in 366 (85.5%), preoperatively in 20 (4.7%), and intraoperatively or unknown in 42 (9.8%). Patients who received any adjuvant radiotherapy were on average 5 years younger than those who underwent surgery alone (P < .0001). Radiotherapy was more commonly used among whites than African Americans (25.8% vs. 16.7%; P = .02) and there was significant variation in the use of adjuvant radiotherapy by geographic location (P = .003). On multivariate analysis, race (P = 0.004), age (P < .0001), and geographic location (P = .006) were independently associated with the use of adjuvant radiotherapy.

CONCLUSION

The incidence of RPS, a rare disease, appears stable. Most patients who undergo surgery do not receive any adjuvant radiotherapy, and very few receive preoperative radiotherapy. Differences in adjuvant radiotherapy use related to demographic and geographic factors suggest that at least some treatment variations reflect differences in individual and institutional practice patterns.

Access to Care and Satisfaction in Colorectal Cancer Patients

This study described the various components of access to care for resectable colorectal cancer, and correlated the timeliness of these components with patient satisfaction. With a prospective/retrospective cohort design, all patients undergoing surgical resection for primary colorectal cancer from 2/1/01 to 15/12/01, were identified during their admission for surgery. A comprehensive, standardized method of ascertaining specific time intervals, which included a patient interview, was used. A patient satisfaction questionnaire was developed, tested, and used in consenting patients. Over the study period, 118 patients underwent colorectal cancer resection. Of these, 110 (93%) consented to participate and 101 (86%) completed the satisfaction questionnaire, including test-retest. The median time intervals (interquartile range) for the various components of access to care were as follows: symptoms to first physician visit, 32 days (10-75); first physician visit to diagnosis, 88 days (44-218); diagnosis to surgery, 19 days (10-44); surgery to chemotherapy (where applicable), 54 days (47-72). On multivariate analysis, tumor location in the rectum was associated with longer prediagnosis intervals, whereas increasing tumor stage was associated with shorter intervals from diagnosis to surgery. Variation in the time interval from diagnosis to surgery was associated with patient satisfaction (r = 0.49; P < 0.0001). Substantially less correlation was identified between patient satisfaction and the time from first physician visit to diagnosis (r = 0.25, P = 0.04). No significant correlation was identified between patient satisfaction scores and the time interval from symptoms to first physician visit (r = 0.11; P = 0.7). Despite concerns regarding surgical waitlists, the longest time intervals experienced by colorectal cancer patients precede diagnosis. However, variations in the relatively short time period from diagnosis to surgery appeared to have the most impact on patient satisfaction. Interventions which improve the timeliness of specific components of access to care may not necessarily result in improved patient satisfaction.

Cyclin D1 polymorphism (G870A) and risk for esophageal adenocarcinoma

BACKGROUND

To investigate individual susceptibility to gastroesophageal reflux disease, Barrett esophagus, and esophageal adenocarcinoma, the authors studied the frequency of the common G870A polymorphism of CCND1, which encodes cyclin D1, a key cell cycle regulatory protein.

METHODS

The study population included 307 patients who were enrolled in a prospective case-control study to evaluate lifestyle risk factors and molecular alterations in gastroesophageal reflux disease (n = 126 patients), Barrett esophagus (n = 125 patients), and esophageal adenocarcinoma (n = 56 patients). A control group included 95 strictly asymptomatic individuals. Genomic DNA was extracted from cases and controls, and polymerase chain reaction was used to amplify exon 4 of CCND1. After digestion with BsrI, acrylamide gel electrophoresis was used to identify the wild type and common G870A polymorphic alleles. The frequency of alleles (G/G, G/A, A/A) was compared between cases and controls. Immunohistochemistry was used to study cyclin D1 distribution in among patients in the case group.

RESULTS

Compared with the asymptomatic control group, and adjusted for age and gender, increasing frequencies were seen for the A/A genotype in patients with gastroesophageal reflux disease (odds ratio [OR], 2.83; 95% confidence interval [95% CI], 1.09-7.34), Barrett esophagus (OR, 3.69; 95% CI, 1.46-9.29), and esophageal adenocarcinoma (OR, 5.99; 95% CI, 1.86-18.96). No association was seen between genotype and cyclin D1 overexpression.

CONCLUSIONS

The CCND1 A/A genotype was associated with increased risk for gastroesophageal reflux disease, Barrett esophagus, and esophageal adenocarcinoma. The contribution of this polymorphism to susceptibility of defined stages of progression to esophageal adenocarcinoma suggested potential application in endoscopic Barrett surveillance programs.

Polymorphisms in DNA repair genes in the molecular pathogenesis of esophageal (Barrett) adenocarcinoma

To test the hypothesis that aberrations of DNA repair contribute to susceptibility for the progression of gastroesophageal reflux disease (GERD) into Barrett esophagus (BE) and esophageal adenocarcinoma (EADC), we studied the frequency of polymorphisms of selected DNA repair genes in patients with GERD (n = 126), BE (n = 125) and EADC (n = 56) enrolled in a 2-year prospective case-control study. Controls comprised 95 strictly asymptomatic healthy individuals. Using genomic DNA extracted from blood samples, we identified wild-type and polymorphic variants of XPD (Arg156Arg and Lys751Gln), XRCC1 (Arg194Trp and Arg399Gln) and XRCC3 (Thr241Met), and the poly (AT) insertion/deletion of XPC (PAT). Allelic frequencies were compared between cases and controls using logistic regression to calculate age, gender, smoking and alcohol-adjusted odds ratios (OR) and 95% confidence intervals (CI). Patients with EADC demonstrated a significantly higher frequency of the XPC PAT homozygous variant genotype compared with asymptomatic controls (OR = 3.82; 95% CI = 1.05-13.93). Significantly reduced frequencies were seen for the XPD Lys751Gln homozygous variant genotype in patients with EADC (OR = 0.24; 95% CI = 0.07-0.88), and for the XRCC1 Arg399Gln homozygous variant genotype in patients with BE (OR = 0.38; 95% CI = 0.12-0.64) and GERD (OR = 0.29; 95% CI = 0.12-0.66). We conclude that the malignant phenotype probably results from a summation of polymorphic nucleotide excision repair genes showing opposing effects (an increased risk of XPC versus a protective effect of XPD). The protective effect of the homozygous variant of XRCC1 Arg399Gln for GERD and BE suggests that base excision repair alterations may occur early in progression to EADC, likely in response to GERD-induced endogenous oxidative or inflammatory DNA damage. As GERD and BE are highly prevalent in the general population, this protective effect may well explain why only a fraction of individuals with GERD and BE progress into invasive EADC.

Ten years of breast screening in the Nova Scotia Breast Screening Program, 1991-2001. experience: use of an adaptable stereotactic device in the diagnosis of screening-detected abnormalities

OBJECTIVE

To evaluate and present 10-year outcomes of the Nova Scotia Breast Screening Program (NSBSP), a population-based screening program in the province of Nova Scotia, Canada, total population 900 000.

SETTING

Organized Breast Screening Program in Nova Scotia, Canada.

METHODS

Rates of participation, abnormal referrals, cancer detection rates, and benign:malignant (B:M) rates for core biopsy and surgical biopsy were calculated for asymptomatic women receiving a mammogram through the NSBSP 1991-2001.

RESULTS

Of 192 454 mammograms performed on 71 317 women, 33% were aged 40 to 49 years, 39% aged 50 to 59 years, 23% aged 60 to 69 years, and 5% aged 70 years and over. Cancer detection rate increased in each age group respectively: 3.7, 5.8, 9.7, and 13.5 per 1000 population on first-time screens. The positive predictive value of an abnormal screen increased with increasing age groups. Benign breast surgery decreased with increased use of needle core breast biopsy (NCBB). Open surgery decreased from 25 to 6 surgeries per 1000 screens. Of 1519 open surgical procedures (1328 women), 878 cancers were removed, with 37% 10 mm or less, and 61% 15 mm or less. In 613 women in whom the node status was assessed, 79% were negative.

CONCLUSION

A quality screening program incorporating NCBB in the diagnostic work-up is effective in the early detection of breast cancer and results in less open surgery, particularly in younger women.

Ductal carcinoma in situ in core biopsies containing invasive breast cancer: correlation with extensive intraductal component and lumpectomy margins

BACKGROUND AND OBJECTIVES

The diagnosis of invasive breast cancer is most commonly made on image-guided core biopsy (CB). The presence of extensive intraductal component (EIC), as identified on subsequent lumpectomy, is associated with an increased risk of positive margins and need for further surgery. CBs demonstrating invasive breast cancer may also contain ductal carcinoma in situ (DCIS), although the significance of this finding is unclear. The objective of this study was to examine the implications of DCIS found in the original CB, specifically related to the risk of EIC and/or positive lumpectomy margins.

METHODS

All patients at a single academic institution who underwent initial breast conserving surgery for invasive breast cancer diagnosed on image-guided CB between 05/00 and 04/02 were included in the study. A systematic, blinded review of all CB and lumpectomy specimens was performed using standardized criteria for DCIS, EIC, and margins.

RESULTS

A total of 95 patients were included in the study, with a mean of 5 (median 5) CB/patient. Of these, 43 (45%) patients had DCIS identified in their CB; in 34 (79%) of these patients, the DCIS was mixed with the invasive cancer. No differences in tumor size or lumpectomy volume were identified between patients with or without DCIS on CB. However, patients with DCIS were noted to be significantly younger. Overall, EIC was identified in 13 (14%) patients; the risk of EIC was significantly higher in patients with DCIS identified in CB than in those with invasive carcinoma alone (30% vs. 0%, respectively; P < 0.0001). Expectedly, the incidence of positive margins on lumpectomy was higher in patients with EIC (38% vs. 16%; P = 0.05). A trend, although not statistically significant, towards positive margins was also noted in patients with DCIS on CB compared to those with invasive carcinoma alone (24% vs. 15%, P = 0.3).

CONCLUSIONS

The identification of DCIS in conjunction with invasive cancer on CB appears important; the absence of DCIS in a CB sample excludes the possibility of eventually identifying EIC. Knowledge of DCIS in CBs with invasive carcinoma may be helpful for surgeons in planning gross resection margins at lumpectomy.

Microsatellite instability in esophageal adenocarcinoma

The frequency of microsatellite instability (MSI), a result of defective mismatch repair during DNA replication, has been reported inconsistently in primary esophageal adenocarcinoma (EADC). Using a panel of 15 markers, the primary aim of this study was to analyze the frequency of MSI in a well-characterized series of 27 primary EADCs, defined according to strict clinicopathologic criteria. Polymerase chain reaction was used to amplify the following microsatellite repeat loci: D2S123, D10S197, D2S119, D11S904, D2S147, D3S1764, D7S1830, D7S1805, D2S434, D9S299, BAT25, BAT26, D5S346, D17S250, and TGF-beta-RII. Tumors were classified as microsatellite-stable (MSS) when no alterations were seen in tumor DNA compared to matched normal tissues, low-level MSI (MSI-L) when 1-5 of 15 markers were altered, and high-level MSI (MSI-H) when more than five markers were altered. Using these stringent criteria, 9/27 (33%) tumors were MSS, 18/27 (67%) tumors were MSI-L, and no tumor was MSI-H. Immunohistochemistry demonstrated cell nuclear expression of DNA mismatch repair proteins (both hMLH1 and hMSH2) in 78% (21/27) of tumors. No associations were seen between MSI and immunohistochemical expression of hMLH1, hMSH2, alterations in p53 or MBD4, tumor grade, pathologic stage, or patient survival. In conclusion, the finding of low levels of MSI in most tumors suggests an inherent baseline genomic instability, and potentially increased susceptibility to mutations during the progression of esophageal adenocarcinoma.

Cost-effectiveness of pulmonary resection and systemic chemotherapy in the management of metastatic soft tissue sarcoma: a combined analysis from the University of Texas M. D. Anderson and Memorial Sloan-Kettering Cancer Centers

BACKGROUND

We sought to determine the cost-effectiveness of different treatment strategies for patients with pulmonary metastases from soft tissue sarcoma.

METHODS

We constructed a decision tree to model the outcomes of 4 treatment strategies for patients with pulmonary metastases from soft tissue sarcoma: pulmonary resection, systemic chemotherapy, pulmonary resection and systemic chemotherapy, and no treatment. Data from 1124 patients with pulmonary metastases from soft tissue sarcoma were used to estimate disease-specific survival for pulmonary resection and no treatment. Outcomes of systemic chemotherapy and pulmonary resection and of systemic chemotherapy were estimated by assuming a 12-month improvement in disease-specific survival with chemotherapy; this was done on the basis of the widely held but unproven assumption that chemotherapy provides a survival benefit in patients with metastatic soft tissue sarcoma. Direct costs were examined for a series of patients who underwent protocol-based pulmonary resection or doxorubicin/ifosfamide-based chemotherapy.

RESULTS

The mean cost of pulmonary resection was 20,339 dollars per patient; the mean cost of 6 cycles of chemotherapy was 99,033 dollars. Compared with no treatment and assuming a 12-month survival advantage with chemotherapy, the incremental cost-effectiveness ratio was 14,357 dollars per life-year gained for pulmonary resection, 104,210 dollars per life-year gained for systemic chemotherapy, and 51,159 dollars per life-year gained for pulmonary resection and systemic chemotherapy. Compared with pulmonary resection, the incremental cost-effectiveness ratio of pulmonary resection and systemic chemotherapy was 108,036 dollars per life-year gained. Sensitivity analyses showed that certain patient and tumor features, as well as the assumed benefit of chemotherapy, affected cost-effectiveness.

CONCLUSIONS

For patients with pulmonary metastases from soft tissue sarcoma who were surgical candidates, pulmonary resection was the most cost-effective treatment strategy evaluated. Even with favorable assumptions regarding its clinical benefit, systemic chemotherapy alone, compared with no treatment, was not a cost-effective treatment strategy for these patients.

Practice patterns in breast cancer surgery: Canadian perspective

Breast cancer is a common disease, and the surgical management is continually evolving. The objective of this study was to describe the current breast cancer practice patterns among Canadian surgeons. All active General Surgeons (n=1172), as accredited by the Royal College of Physicians and Surgeons of Canada, were sent a 31-item questionnaire. Anonymous responses were collected and analyzed regarding surgeon demographics, practice, and perceptions regarding surgical care of breast cancer patients. Overall 640 active surgeons responded; of these, 519 (81%) treated breast cancer and formed the study cohort. Practice settings included community (55%), community with university affiliation (28%), and academic (17%). The majority of surgeons (76%) stated that <25% of their practice was devoted to breast disease, and 42% performed < or =2 breast cancer operations/month. Immediate breast reconstruction (IBR) was used by 57% of surgeons. On multivariate analysis, higher surgeon volume of breast cancer cases (p=0.0008), fellowship training in Surgical Oncology (p=0.009), community population (p=0.001), and academic practice setting (p<0.0001) were independently associated with the use of IBR. Of the 640 surgeons who responded, 79% stated that breast cancer surgery should be performed by "most general surgeons." In Canada, most breast cancer surgery was performed by general surgeons who did not appear to have an interest, as defined by training or clinical volume, in breast cancer. Although variability regarding specific surgical issues was found among subgroups of surgeons, the majority of respondents felt that most general surgeons should treat breast cancer.

Clinical implications of p53 tumor suppressor gene mutation and protein expression in esophageal adenocarcinomas: results of a ten-year prospective study

OBJECTIVE

This study was undertaken to characterize the spectrum of p53 alterations (mutations and protein expression) in surgically resected esophageal adenocarcinomas, and to correlate molecular alterations with clinicopathologic findings and outcome.

METHODS

Between 1991 and 2001, 91 consecutive patients with esophageal adenocarcinomas underwent subtotal esophagectomy. No patient received induction therapy. Strict clinicopathologic criteria were used to define primary esophageal adenocarcinomas. Genomic DNA was extracted from esophageal tumors, each matched with histologically normal esophageal epithelium (internal control) from the resection margin. Polymerase chain reaction was used to amplify p53 exons 4 through 10. Mutations were studied by single-strand conformation polymorphism analysis and direct DNA sequencing. Immunohistochemical testing (monoclonal antibody DO7) was used to evaluate p53 protein distribution.

RESULTS

Five-year overall survival was 27.3%. No p53 alterations (mutations and/or protein overexpression) were found in normal esophageal epithelium. A total of 57.1% (n = 52) of tumors had p53 alterations (mutations and/or protein overexpression), which on univariate analysis were associated with poor tumor differentiation (P =.001), advanced pTNM stage (P =.009), and number of involved lymph nodes (0, 1-3, >3; P =.04). Patients with p53 alterations had significantly reduced 5-year overall survival relative to patients with wild-type p53 (15% vs 46%; P =.004). The p53 mutations were predominantly G:C to A:T transitions at CpG dinucleotides (52.2%, 24/46)

CONCLUSIONS

We conclude that p53 alterations (mutations and/or protein overexpression) are a predictor of reduced postoperative survival after surgical resection of esophageal adenocarcinomas and that p53 may be a clinically useful molecular marker for stratifying patients in future clinical trials. Patterns of p53 mutations suggest endogenous mutational mechanisms.

Evolution and critical appraisal of anastomotic technique following resection of esophageal adenocarcinoma

The aim of this study was to critically evaluate acute and long-term complications of hand-sewn and semimechanical cervical esophagogastric anastomosis following resection of primary esophageal adenocarcinoma. Between February 1991 and 2001, 91 consecutive patients underwent subtotal esophagectomy (transthoracic, n=49; transhiatal, n=42), transposing a gastric tube based on the right gastroepiploic artery. All esophagogastric anastomoses were performed in the left neck using a hand-sewn technique (n=53) and, from September 1997, a side-to-side semimechanical technique (n=38). Outcomes evaluated were anastomotic leak rates, length of stay, and development of strictures. Postoperative mortality was 4.4% (all cardiopulmonary causes). Fifty-eight patients (63.7%) had an uncomplicated postoperative course, with a median postoperative length of stay of 10 days (vs. 20 days with associated morbidity; P </= 0.001). Anastomotic leaks were the leading cause of postoperative morbidity (16.5%, 15/91), and were classified into four types based on severity. The semimechanical anastomotic technique was associated with a reduced leak rate compared with the hand-sewn technique (7.9%, 3/38 vs. 22.6%, 12/53; P=0.08), although different patterns of anastomotic failure were seen following semimechanical anastomoses, with increased mediastinal and pleural sepsis. Anastomotic strictures developed in nine (17.0%) hand-sewn and three (7.9%) semimechanical anastomoses. Our conclusion was that a semimechanical technique for cervical esophagogastrostomy is associated with reduced anastomotic leak rates compared with hand-sewn anastomoses, resulting in a shorter postoperative stay. Patterns of anastomotic failure varied between each technique, possibly as a consequence of a longer cervical esophageal segment required for construction of a semimechanical anastomosis. The association between anastomotic technique and stricture development was not clear from this study.

Sentinel lymph node biopsy in breast cancer: Canadian practice patterns

BACKGROUND

Recent data suggest sentinel lymph node biopsy (SLNBx) for invasive breast cancer (IBC) is widely performed in the United States, often outside of a clinical trial. We sought to describe SLNBx practice patterns in Canada, as well as criteria for abandonment of concurrent axillary lymph node dissection.

METHODS

All active (n = 1172) general surgeons in Canada were sent a 31-item questionnaire.

RESULTS

Of the 519 respondents who treated IBC, 138 (27%) performed SLNBx, whereas 378 (73%) did not. Surgeons who did not perform SLNBx most commonly cited a lack of adequate resources (64%). Of the 138 surgeons who performed SLNBx, 16% participated in one of the ongoing multicenter clinical trials. Of the 39 (28%) surgeons who abandoned routine concurrent axillary lymph node dissection, 20 (51%) performed <30 combined procedures before performing SLNBx alone. On multivariate analysis, surgical oncology training (P =.005), increasing proportion of practice devoted to breast disease (P <.001), and number of days per week in the operating room (P <.001) were associated with the use of SLNBx.

CONCLUSIONS

In contrast to the United States, SLNBx for IBC in Canada was not as common, and few surgeons participated in clinical trials. Fellowship-trained surgical oncologists and surgeons with a high exposure to breast disease seemed to be most involved in the development of SLNBx for IBC.

Presence of the human leukocyte antigen class II gene DRB1*1101 predicts interferon gamma levels and disease recurrence in melanoma patients

BACKGROUND

Increased interferon gamma (IFN-gamma) levels are an independent predictor of melanoma recurrence. Human leukocyte antigen (HLA) class II genes can regulate cytokine production; we investigated whether these genes would predict IFN-gamma levels and recurrence in melanoma patients.

METHODS

Of 591 patients who presented with localized melanoma, 579 underwent identification of HLA class II alleles; 233 melanoma patients and 90 controls underwent determination of plasma IFN-gamma levels. HLA class II genes were examined for association with IFN-gamma levels and disease recurrence.

RESULTS

After a median follow-up of 60 months, melanoma patients with IFN-gamma levels above the mean control value were more likely to have developed disease recurrence compared with patients with levels below the mean. The HLA class II gene HLA-DRB1*1101 was the strongest predictor of recurrence, and HLA-DRB1*1101-positive melanoma patients had increased levels of IFN-gamma compared with patients lacking the gene.

CONCLUSIONS

Among patients with localized melanoma, both HLA-DRB1*1101 and increased IFN-gamma levels were associated with an increased risk for recurrence; HLA-DRB1*1101-positive patients had relatively increased levels of IFN-gamma. HLA class II genes may mediate cytokine production in melanoma patients, and this mechanism may help determine the risk of disease recurrence.

Cost-effectiveness of staging computed tomography of the chest in patients with T2 soft tissue sarcomas

BACKGROUND

Published practice guidelines recommend routine chest computed tomography (CT) scanning as part of the staging evaluation for patients with T2 soft tissue sarcomas (STS), although there is no direct evidence to support this practice. The objective of this study was to determine the yield and cost-effectiveness of routine versus selective chest CT scanning for the staging of patients with T2 STS and to identify any subgroups for whom a more selective approach to chest CT scanning could be considered.

METHODS

Six hundred consecutive patients with primary, nonthoracic, T2 (> 5 cm) STS underwent both chest X-ray (CXR) and chest CT scanning to evaluate the presence of pulmonary metastatic disease (M1). The authors constructed a decision tree that modeled the outcomes of diagnostic testing for two hypothetical diagnostic strategies: 1) routine chest CT (rCT) or 2) CXR and selective chest CT (sCT). The yield and cost of each strategy were determined; the incremental cost-effectiveness ratio (ICER) was calculated as the cost per additional patient with pulmonary metastases identified by rCT versus sCT.

RESULTS

The yield of rCT was higher than that of sCT (M1 disease identified in 19.2% vs. 16.0% of patients, respectively), but rCT was more costly ($1301 vs. $418 per patient, respectively). The ICER of rCT compared with sCT was $27,594 per patient identified with pulmonary metastasis. The expected yields, costs, and ICERs of the diagnostic strategies varied across patient subgroups based on grade, anatomic site, and tumor size.

CONCLUSIONS

For patients with T2 STS, rCT was most cost-effective in patients with high-grade lesions or extremity lesions. The findings of this study do not support the routine use of chest CT scanning in all patients with T2 STS.

Hepatitis B or C virus serology as a prognostic factor in patients with hepatocellular carcinoma

It is not clear whether chronic hepatitis B or C virus (HBV or HCV) infection is a prognostic factor for hepatocellular carcinoma. We performed this study to determine if chronic HBV or HCV infection had any impact on postresection survival or affected patterns of failure. The records of 77 patients undergoing surgical resection for hepatocellular carcinoma between January 1990 and December 1998 were reviewed. Forty-four patients (57%) had HCV infection, 18 patients (23%) had HBV infection, and 15 patients (20%) had negative serology. There were no differences in age, sex, or tumor size among the groups, and all patients had margin-negative resections. There was a significantly higher incidence of satellitosis and vascular invasion in patients with HCV infection (32% and 41% respectively; P <0.05 vs. other groups). With a median follow-up of 30 months, a significantly decreased local disease-free survival (LDFS) was seen in HBV-positive (5-year LDFS 26%) or HCV-positive (5-year LDFS 38%) patients compared to those with negative serology (5-year LDFS 79%; P <0.05). There was also a trend toward a decreased overall survival in patients with positive hepatitis serology compared to patients with negative serology (37% vs. 79%; P = 0.12). Univariate analysis revealed that only satellitosis was related to local recurrence and overall survival. Patients with positive serology for hepatitis B or C undergoing resection for hepatocellular carcinoma have a trend toward worse overall prognosis and a significantly decreased LDFS when compared to patients with negative serology.

Ontogeny of humoral heart rate regulation in the embryonic mouse

Catecholamines, acetylcholine, and adenosine are known to influence cardiac function, yet the effects of these agents on mammalian embryonic myocardium are largely unknown. To address this issue, we compared the chronotrophic effects of adenosinergic, adrenergic, and muscarinic agents on cultured murine embryos from postcoital day (PC) 8.0, when the fusing heart tubes first begin to beat, to PC 14, when cardiogenesis is essentially complete. At PC 8.0 and older, A(1)-adenosine receptor (A(1)AR) activation significantly decreased heart rates. Adrenergic stimulation caused modest increases in heart rates (145-155% of baseline) beginning at PC 9.0. Muscarinic activation decreased heart rates only after PC 13. When receptor gene expression was examined, A(1)ARs and beta(1)ARs were expressed in isolated hearts as early as PC 9.0, and beta(2)ARs and m(2)-muscarinic receptor genes were expressed at PC 11.0. These results identify the adenosinergic system as the earliest and most potent regulator of embryonic cardiac function and show that prenatal responsiveness to catecholamines and acetylcholine develops at later embryonic stages.