Changes in preoperative endoscopic and percutaneous bile drainage in patients with periampullary cancer undergoing pancreaticoduodenectomy in Ontario: effect on clinical practice of a randomized trial.

Background: In 2010, a multicentre randomized controlled trial reported increased postoperative complications in pancreaticoduodenectomy (pde) patients undergoing preoperative biliary decompression (pbd). We evaluated the effect of that publication on rates of pbd at the population level. Methods: This retrospective observational cohort study identified patients undergoing pde for malignancy, 2005-2013, linking them with administrative health care databases covering medical services for a population of 13.5 million. Patients undergoing pbd within 6 weeks before their surgery were identified using physician billing codes and were divided into those undergoing pde before and after article publication, with a 6-month washout period. Chi-square tests were used to compare rates of pbd. Results: Of 1997 pde patients identified, 963 underwent surgery before article publication, and 911, after (123 during the washout period). The rate of pbd was 47.5% before publication, and 41.6% after (p = 0.01). The lowest pbd rates occurred immediately after publication, in 2010 and 2011. Similar results were observed when the cohort was restricted to patients seen preoperatively by a gastroenterologist (n = 1412). Conclusions: Rates of pbd have declined a small, but significant, amount after randomized trial publication. Persistence of pbd might relate to suboptimal knowledge translation, the role of pbd in diagnosis of periampullary malignancy, and treatment of complications (cholangitis, severe hyperbilirubinemia) or anticipation of delay from diagnosis to surgery. The nadir in pbd rates after article publication and the subsequent rise suggest an element of transience in the effect of article publication on clinical practice. Further investigation into the reasons for persistent pbd is needed.

Predictors of adjuvant treatment for pancreatic adenocarcinoma at the population level.

BACKGROUND: In the present study, we aimed to describe, at the population level, patterns of adjuvant treatment use after curative-intent resection for pancreatic adenocarcinoma (pcc) and to identify independent predictors of adjuvant treatment use. METHODS: In this observational cohort study, patients undergoing pcc resection in the province of Ontario (population 13 million) during 2005-2010 were identified using the provincial cancer registry and were linked to administrative databases that include all treatments received and outcomes experienced in the province. Patients were defined as having received chemotherapy (ctx), chemoradiation (crt), or observation (obs). Clinicopathologic factors associated with the use of ctx, crt, or obs were identified by chi-square test. Logistic regression analyses were used to identify independent predictors of adjuvant treatment versus obs, and ctx versus crt. RESULTS: Of the 397 patients included, 75.3% received adjuvant treatment (27.2% crt, 48.1% ctx) and 24.7% received obs. Within a single-payer health care system with universal coverage of costs for ctx and crt, substantial variation by geographic region was observed. Although the likelihood of receiving adjuvant treatment increased from 2005 to 2010 (p = 0.002), multivariate analysis revealed widespread variation between the treating hospitals (p = 0.001), and even between high-volume hepatopancreatobiliary hospitals (p = 0.0006). Younger age, positive lymph nodes, and positive surgical resection margins predicted an increased likelihood of receiving adjuvant treatment. Among patients receiving adjuvant treatment, positive margins and a low comorbidity burden were associated with crt compared with ctx. CONCLUSIONS: Interinstitutional medical practice variation contributes significantly to differential patterns in the rate of adjuvant treatment for pcc. Whether such variation is warranted or unwarranted requires further investigation.

Regional variation in the management of metastatic gastric cancer in Ontario.

BACKGROUND: Geographic variation in cancer care is common when clear clinical management guidelines do not exist. In the present study, we sought to describe health care resource consumption by patients with metastatic gastric cancer (gc) and to investigate the possibility of regional variation. METHODS: In this population-based cohort study of patients with stage iv gastric adenocarcinoma diagnosed between 1 April 2005 and 31 March 2008, chart review and administrative health care data were linked to study resource utilization outcomes (for example, clinical investigations, treatments) in the province of Ontario. The study took a health care system perspective with a 2-year time frame. Chi-square tests were used to compare proportions of resource utilization, and analysis of variance compared mean per-patient resource consumption between geographic regions. RESULTS: A cohort of 1433 patients received 4690 endoscopic investigations, 12,033 computed tomography exams, 12,774 radiography exams, and 5059 ultrasonography exams. Nearly all patients were seen by a general practitioner (98%) and a specialist (99%), and were hospitalized (95%) or visited the emergency department (87%). Fewer than half received chemotherapy (43%), gastrectomy (37%), or radiotherapy (28%). The mean number of clinical investigations, physician visits, hospitalizations, and instances of patient accessing the emergency department or receiving radiotherapy or stent placement varied significantly by region. CONCLUSIONS: Variations in health care resource utilization for metastatic gc patients are observed across the regions of Ontario. Whether those differences reflect differential access to resources, patient preference, or physician preference is not known. The observed variation might reflect a lack of guidelines based on high-quality evidence and could partly be ameliorated with regionalization of gc care to high-volume centres.

Negative predictive value of preoperative computed tomography in determining pathologic local invasion, nodal disease, and abdominal metastases in gastric cancer.

BACKGROUND: Before undergoing curative-intent resection of gastric adenocarcinoma (ga), most patients undergo abdominal computed tomography (ct) imaging to determine contraindications to resection (local invasion, distant metastases). However, the ability to detect contraindications is variable, and the literature is limited to single-institution studies. We sought to assess, on a population level, the clinical relevance of preoperative ct in evaluating the resectability of ga tumours in patients undergoing surgery. METHODS: In a provincial cancer registry, 2414 patients with ga diagnosed during 2005-2008 at 116 institutions were identified, and a primary chart review of radiology, operative, and pathology reports was performed for all patients. Preoperative abdominal ct reports were compared with intraoperative findings and final pathology reports (reference standard) to determine the negative predictive value (npv) of ct in assessing local invasion, nodal involvement, and intra-abdominal metastases. RESULTS: Among patients undergoing gastrectomy, the npv of ct imaging in detecting local invasion was 86.9% (n = 536). For nodal metastasis, the npv of ct was 43.3% (n = 450). Among patients undergoing surgical exploration, the npv of ct for intra-abdominal metastases was 52.3% (n = 407). CONCLUSIONS: Preoperative abdominal ct imaging reported as negative is most accurate in determining local invasion and least accurate in nodal assessment. The poor npv of ct should be taken into account when selecting patients for staging laparoscopy.