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1.  Emergency surgery for colorectal cancer does not result in nodal understaging compared with elective surgery 
Canadian Journal of Surgery  2014;57(5):349-353.
It has been suggested that inadequate lymph node harvest may result in pathologically understaged or indeterminate staging of patients with colorectal cancer (CRC). We compared the adequacy of nodal staging in patients undergoing emergency surgery compared with elective surgery for CRC.
Using a prospectively collected CRC surgery database at a tertiary care centre, we performed a cohort study. The mean number of lymph nodes harvested and the proportion of patients who had inadequate staging (< 12 nodes harvested) were compared between emergency and elective surgery cohorts. Our analysis was adjusted for tumour site, type of resection, surgical training and pathologic stage.
A total of 1279 of 1356 (94%) enrolled patients had nodal data available for analysis; 161 (13%) patients had emergency surgery and 1118 (87%) had elective surgery. The mean number of nodes removed was higher in the emergency surgery group (mean difference +2.8, 95% confidence interval [CI] 0.6–5.1, p = 0.012). The proportion of patients with inadequate nodal staging did not differ between groups (emergent 16%, elective 17%, p = 0.79). The odds of adequate nodal staging, adjusting for site, type of resection, training and stage was no different between groups (OR 0.80, 95% CI 0.47–1.35, p = 0.41).
The evidence does not support the common belief that emergency surgery is more commonly understaged in CRC. Our data suggest emergency surgery resulted in a significant increase in the average number of nodes harvested, with no difference in inadequate nodal staging.
PMCID: PMC4183683  PMID: 25265110
2.  Microbiota of Human Breast Tissue 
Applied and Environmental Microbiology  2014;80(10):3007-3014.
In recent years, a greater appreciation for the microbes inhabiting human body sites has emerged. In the female mammary gland, milk has been shown to contain bacterial species, ostensibly reaching the ducts from the skin. We decided to investigate whether there is a microbiome within the mammary tissue. Using 16S rRNA sequencing and culture, we analyzed breast tissue from 81 women with and without cancer in Canada and Ireland. A diverse population of bacteria was detected within tissue collected from sites all around the breast in women aged 18 to 90, not all of whom had a history of lactation. The principal phylum was Proteobacteria. The most abundant taxa in the Canadian samples were Bacillus (11.4%), Acinetobacter (10.0%), Enterobacteriaceae (8.3%), Pseudomonas (6.5%), Staphylococcus (6.5%), Propionibacterium (5.8%), Comamonadaceae (5.7%), Gammaproteobacteria (5.0%), and Prevotella (5.0%). In the Irish samples the most abundant taxa were Enterobacteriaceae (30.8%), Staphylococcus (12.7%), Listeria welshimeri (12.1%), Propionibacterium (10.1%), and Pseudomonas (5.3%). None of the subjects had signs or symptoms of infection, but the presence of viable bacteria was confirmed in some samples by culture. The extent to which these organisms play a role in health or disease remains to be determined.
PMCID: PMC4018903  PMID: 24610844
3.  An acute care surgery service expedites the treatment of emergency colorectal cancer: a retrospective case–control study 
Emergency colorectal cancer (CRC) is a complex disease that requires multidisciplinary approaches for management. However, it is unclear whether acute care surgery (ACS) services can expedite the workup and treatment of complex surgical diseases such as emergency CRC. We sought to assess the impact of an Acute Care and Emergency Surgery Service (ACCESS) on wait-times for inpatient colonoscopy and surgical resection among emergency CRC patients.
This retrospective case–control study was conducted at a tertiary-care, university-affiliated, cancer centre in London, Ontario, Canada. All patients aged 18 or older who presented to the emergency department with a recent (within 48 hours) diagnosis of CRC, or were diagnosed with CRC after admission, were included in the study. Patients were either in the pre-ACCESS (July 1, 2007-June 31, 2010) or post-ACCESS (July 1, 2010-June 30, 2012) groups. A third group of emergency CRC patients treated at an adjacent cancer centre that lacked ACCESS (non-ACCESS) was evaluated separately. The primary outcome was time from admission to colonoscopy and surgery.
A total of 149 patients (47 pre-ACCESS, 37 post-ACCESS, and 65 non-ACCESS) were identified. Only 19% (n = 9) of pre-ACCESS patients underwent inpatient colonoscopy, compared to 38% (n = 14) in the post-ACCESS group (p = 0.023). Additionally, 100% of patients in the post-ACCESS era underwent inpatient colonoscopy and surgery during the same admission, compared to only 44% of pre-ACCESS patients (p = 0.006). Median wait-times for inpatient colonoscopy (2.0 and 1.8 days for pre- and post-ACCESS groups respectively, p = 0.08) and surgical resection (1.6 and 2.3 days for pre- and post-ACCESS groups respectively, p = 0.40) were similar.
Patients admitted to ACCESS underwent more inpatient colonoscopies and were more likely to have definitive surgery on that admission. ACS services can facilitate the workup and management of complex surgical diseases such as emergency CRC without delaying treatment.
PMCID: PMC3994420  PMID: 24656174
Colorectal/anal neoplasia; Colonoscopy; Acute care surgery; Health outcomes
5.  Cost-effectiveness of a 21-gene recurrence score assay versus Canadian clinical practice in women with early-stage estrogen- or progesterone-receptor-positive, axillary lymph-node negative breast cancer 
BMC Cancer  2012;12:447.
A 21-gene recurrence score (RS) assay may inform adjuvant systematic treatment decisions in women with early stage breast cancer. We sought to investigate the cost effectiveness of using the RS-assay versus current clinical practice (CCP) in women with early-stage estrogen- or progesterone-receptor-positive, axilliary lymph-node negative breast cancer (ER+/ PR + LN- ESBC) from the perspective of the Canadian public healthcare system.
We developed a Markov model to project the lifetime clinical and economic consequences of ESBC. We evaluated adjuvant therapy separately in post- and pre-menopausal women with ER+/ PR + LN- ESBC. We assumed that the RS-assay would reclassify pre- and post-menopausal women among risk levels (low, intermediate and high) and guide adjuvant systematic treatment decisions. The model was parameterized using 7 year follow up data from the Manitoba Cancer Registry, cost data from Manitoba administrative databases, and secondary sources. Costs are presented in 2010 CAD. Future costs and benefits were discounted at 5%.
The RS-assay compared to CCP generated cost-savings in pre-menopausal women and had an ICER of $60,000 per QALY gained in post-menopausal women. The cost effectiveness was most sensitive to the proportion of women classified as intermediate risk by the RS-assay who receive adjuvant chemotherapy and the risk of relapse in the RS-assay model.
The RS-assay is likely to be cost effective in the Canadian healthcare system and should be considered for adoption in women with ER+/ PR + LN- ESBC. However, ongoing assessment and validation of the assay in real-world clinical practice is warranted.
PMCID: PMC3488327  PMID: 23031196
Breast cancer; Chemotherapy; Cost-effectiveness; 21-gene recurrence score assay
6.  Recognizing BRCA gene mutation risk subsequent to breast cancer diagnosis in southwestern Ontario 
Canadian Family Physician  2012;58(5):e258-e266.
To describe the population of women in southwestern Ontario who were diagnosed with potentially preventable BRCA mutation–related breast cancer.
Retrospective chart review.
The Cancer Genetics Clinic of the London Regional Cancer Program in London, Ont.
Patients younger than 52 years of age who were referred to the London Regional Cancer Program Cancer Genetics Clinic between 1997 and 2007 for BRCA testing after being diagnosed with breast cancer (N = 1017).
Main outcome measures
The proportion of women with BRCA1 or BRCA2 gene mutations and the proportion of women who would have qualified, based on family cancer history, for referral for genetic counseling and testing before their breast cancer diagnoses.
Among the 1017 women referred for BRCA testing, 63 women younger than 52 years of age who had been diagnosed with breast cancer were found, subsequent to this diagnosis, to have BRCA1 or BRCA2 gene mutations. Of these, 41 (65%) had family cancer histories that would have qualified them for genetic counseling and testing, according to provincial criteria, before their own breast cancer diagnoses. Of the 63 women, most (81%) had been referred for BRCA gene mutation testing by their oncologists or surgeons.
Our results suggest that the diagnosis of breast cancer could have been anticipated, and perhaps in some cases prevented, in up to two-thirds of high-risk women younger than 52 years of age in southwestern Ontario. If the high-risk status of these women had been recognized, they might have had the opportunity to choose genetic counseling, testing, more effective cancer surveillance, and potentially preventive options. The results of this study call for increased public and care provider awareness about hereditary breast cancer risk to promote women’s ability to choose to access genetic counseling.
PMCID: PMC3352812  PMID: 22734169
7.  Tumour dormancy in breast cancer: an update 
Breast Cancer Research  2007;9(3):208.
Delayed recurrences, common in breast cancer, are well explained by the concept of tumour dormancy. Numerous publications describe clinical times to disease recurrence or death, using mathematical approaches to infer mechanisms responsible for delayed recurrences. However, most of the clinical literature discussing tumour dormancy uses data from over a half century ago and much has since changed. This review explores how current breast cancer treatment could change our understanding of the biology of breast cancer tumour dormancy, and summarizes relevant experimental models to date. Current knowledge gaps are highlighted and potential areas of future research are identified.
PMCID: PMC1929094  PMID: 17561992
8.  Surgical case costing: trauma is underfunded according to resource intensity weights 
Canadian Journal of Surgery  2002;45(1):57-62.
To determine whether rate-based funding using resource intensity weights (RIWs) adequately represents trauma case costs.
A prospective time-in-motion resource utilization pilot study to assure the effectiveness of the computerized hospital Transition-One data acquisition system, followed by a retrospective observational case costing study. Patient costs with no identifying data were used, and all costs were tabulated as mean cost per group.
London Health Sciences Centre, London, Ont., a tertiary care “lead” trauma hospital.
A modified random selection of 4 control case mix groups (CMGs) of surgical patients for the fiscal year 1996–97. The trauma group was selected as a representative resource-intensive CMG. Each patient was assigned to a CMG by Health Records according to the most responsible diagnosis.
Outcome measures
Total case costs were tabulated for each patient then combined for a mean case cost per CMG. The RIW assignments for each patient were combined to create a mean RIW per CMG and mean length of stay per CMG.
There was no statistically significant difference between the control surgical CMGs and the trauma CMG for mean RIW-adjusted length of stay per CMG, but there was a significant difference (p < 0.0001) between the control CMGs and the trauma CMG for RIW-adjusted mean case cost per CMG.
RIWs underrepresent trauma case costs by a factor of 3.5, which could result in under-funding and potential fiscal difficulties for leading trauma hospitals as has occurred in the United States.
PMCID: PMC3692706  PMID: 11837923

Results 1-8 (8)