Prognostic factors in metastatic gastric cancer: results of a population-based, retrospective cohort study in Ontario

Abstract

Background Stage IV gastric cancer is lethal, and little population-based research on prognostic factors has been performed in low-incidence countries. Therefore, we investigated the consistency of the associations of patient, disease and healthcare system factors identified in previous population-based research to understand their generalizability to other low-incidence populations. Methods A population-based, retrospective cohort study of patients diagnosed with Stage IV gastric cancer in Ontario between 1 April 2005 and 31 March 2008 was performed. Kaplan-Meier methodology and the log-rank test were used for bivariate analysis. Multivariate Cox proportional hazard regression was performed. Hazard ratios (HRs) and 95 % confidence intervals (CIs) are presented.Results On multivariate analysis, patient, disease and healthcare system factors were independent predictors of survival. Increasing age per 10 years (HR 1.07; 95 % CI 1.02-1.10), a tumor located in the gastroesophageal junction (HR 1.09; 95 % CI 0.94-1.27) or middle of the stomach (HR 1.14; 95 % CI 0.97-1.35), presence of carcinomatosis (HR 1.61; 95 % CI 1.42-1.83) and a larger burden of metastatic disease (2-3 sites of metastatic disease: HR 1.17; 95 % CI 1.03-1.32; C4 sites: HR 1.69; 95 % CI 1.30-2.20) were associated with worse prognosis. Female gender, receipt of surgery, chemotherapy and radiotherapy and treatment from a high-volume, gastric cancer specialist were all associated with significantly better prognosis. In addition, there was evidence of significant geographic variation in survival. Conclusion This study provides supporting evidence for patient, disease and healthcare system prognostic factors in metastatic gastric cancer. Future work investigating the 123Gastric Cancer (2016( ) 19:150-159 DOI 10.1007 role of emerging molecular and biologic information will need to take these established prognostic factors into consideration.

Predictors of Adjuvant Treatment for Pancreatic Adenocarcinoma at the Population Level

“…Through those databases, the universal single-payer health care system in Ontario can capture details for all health care encounters, hospitalizations, procedures, and prescription medications dispensed (including chemotherapy and radiation) for all patients treated for pcc. The same methods have previously been described for other cancers 14,15 . Patients were followed until 31 March 2012.…”

“…The location of a patient's primary residence was determined using the postal code and was aggregated into a geographic region corresponding to a governmentallydesignated local health integration network (http://www. lhins.on.ca/home.aspx), through which all health services are organized and delivered in Ontario 15,20 . Receipt of treatment at 1 of the 10 designated high-volume hepatopancreatobiliary (hpb) centres was also recorded, with all patients not treated at such a centre being grouped into a single category.…”

Regional Variation in the Management of Metastatic Gastric Cancer in Ontario

“…Dixon et al 19 identified geographic differences in mortality for metastatic gastric cancer patients between regions in Ontario. The differences in utilization identified in the present study could suggest avenues of investigation to explain those negative health outcomes and approaches to make access to treatments more equitable across the province.…”

“…Hospitalizations represent a major contributor to costs, and there is little understanding of how other resource utilization factors contribute to those high costs 15,16,18 . Variations in prognosis for metastatic gastric cancer patients have been identified between geographic areas in many low-incidence countries and within single health systems, and whether variation in clinical practice is a contributing factor is unknown [19][20][21] . Few investigations of regional variation for the most common treatment modalities (gastrectomy, chemotherapy, radiotherapy) have been published 21,22 .…”

Beyond the dollar: Influence of sociodemographic marginalization on surgical resection, adjuvant therapy, and survival in patients with pancreatic cancer

“…CIHI databases contain details regarding all in‐hospital procedures, the National Ambulatory Care Reporting System includes data concerning ambulatory and emergency care, OHIP contains physician claims for all insured services, and the RPDB includes sociodemographic information and death certificates. These methods previously have been described for cancers originating in other organs …”