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Stage, treatment and outcomes for patients with breast cancer in British Columbia in 2002: a population-based cohort study.

ABSTRACT: BACKGROUND:There are very few long-term Canadian data on breast cancer outcomes by stage. We described the stage, treatment and outcomes of breast cancer at a population level for patients in British Columbia. METHODS:This population-based cohort study included almost all patients with incident breast cancer registered in 2002 (about 97.6% registry case completeness). For these patients, information on stage, primary local surgery, radiotherapy, chemotherapy, hormone therapy and survival outcome (based on registry date and cause-of-death data) were available. We calculated Kaplan-Meier curves for breast cancer-specific survival and overall survival by stage and analyzed prognostic and treatment factors with a multivariable Cox model. RESULTS:The 2927 incident cases of breast cancer identified in 2002 had the following distribution by stage: stage 0 (in situ), 424 (14%); stage I, 1118 (38%); stage II, 938 (32%); stage III, 233 (8%); stage IV, 123 (4%); unknown, 91 (3%). The distribution of patients' ages was < 40 years, 127 (4%); 40-49, 538 (18%); 50-59, 719 (25%); 60-69, 660 (23%); 70-79, 583 (20%); ? 80, 300 (10%). Within the first year after diagnosis, radiotherapy was provided to 1649 patients (56%), chemotherapy to 928 (32%) and hormone therapy to 1664 (57%). Ten-year breast cancer-specific survival rates by stage were > 99% for stage 0, 95% for stage I, 81% for stage II, 55% for stage III and 4% for stage IV. Ten-year overall survival rates were 89% for stage 0, 81% for stage I, 68% for stage II, 43% for stage III and 2% for stage IV. INTERPRETATION:This analysis provides a Canadian benchmark for treatment rates and 10-year outcomes by stage for all incident cases of breast cancer in a single province. Outcomes in British Columbia compared well with published rates for the United States and Europe.

SUBMITTER: Davidson A

PROVIDER: S-EPMC3985980 | biostudies-literature | 2013 Oct

REPOSITORIES: biostudies-literature

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Stage, treatment and outcomes for patients with breast cancer in British Columbia in 2002: a population-based cohort study.

Davidson Ashley A Chia Stephen S Olson Robert R Nichol Alan A Speers Caroline C Coldman Andy J AJ Bajdik Chris C Woods Ryan R Tyldesley Scott S

CMAJ open 20131001 4

<h4>Background</h4>There are very few long-term Canadian data on breast cancer outcomes by stage. We described the stage, treatment and outcomes of breast cancer at a population level for patients in British Columbia.<h4>Methods</h4>This population-based cohort study included almost all patients with incident breast cancer registered in 2002 (about 97.6% registry case completeness). For these patients, information on stage, primary local surgery, radiotherapy, chemotherapy, hormone therapy and s ...[more]

PMID: 25077115

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Project description:BackgroundInformation on the long-term risk of cervical intraepithelial neoplasia (CIN) recurrence among women treated for CIN is limited yet critical for evidence-based surveillance recommendations.MethodsWe retrospectively identified 37,142 women treated for CIN 1, 2, or 3 from January 1, 1986, through December 31, 2000 (CIN cohort), from the British Columbia Cancer Agency cytology database and linked their records with cancer registry and vital statistics data. Treatment included cryotherapy, loop electrosurgical excision procedure, cone biopsy, and laser vaporization or excision. A comparison cohort contained 71,213 women with normal cytology and no previous CIN diagnosis. Follow-up continued through December 31, 2004. Among women in both cohorts under active surveillance, we compared rates of CIN 2 or 3 (CIN 2/3) and cervical cancer. Cumulative incidence rates of CIN 2/3 and 95% confidence intervals (CIs) were estimated by a life table approach by using annual rates. Cumulative rates of invasive cancer were examined by the person-years method.ResultsOverall observed cumulative rates of CIN 2/3 in the first 6 years after treatment were 14.0% (95% CI = 13.84% to 14.15%) for women originally treated for CIN 3, 9.3% (95% CI = 9.09% to 9.42%) for CIN 2, and 5.6% (95% CI = 4.91% to 5.21%) for CIN 1. Annual rates of CIN 2/3 were less than 1% after 6 years. Initial diagnosis, age, and treatment type were associated with a diagnosis of CIN 2/3 after treatment, with 6-year adjusted rates for women aged 40-49 years ranging from 2.6% (95% CI = 1.9% to 3.4%) for treatment of CIN 1 with the loop electrosurgical excision procedure to 34.0% (95% CI = 30.9% to 37.1%) for treatment of CIN 3 with cryotherapy. Overall incidence of invasive cancer (per 100,000 woman-years) was higher in the CIN cohort (37 invasive cancers, 95% CI = 30.6 to 42.5 cancers) than in the comparison cohort (six cancers, 95% CI = 4.3 to 7.7 cancers). Cryotherapy, compared with other treatments, was associated with the highest rate of subsequent disease (adjusted odds ratio for invasive cancer = 2.98, 95% CI = 2.09 to 4.60).ConclusionRisk of CIN 2/3 after treatment was associated with initial CIN grade, treatment type, and age. Long-term risk of invasive cancer remained higher among women treated for CIN, particularly those treated with cryotherapy.

Project description:OBJECTIVES:A current diagnosis of asthma cannot be objectively confirmed in many patients with physician-diagnosed asthma. Estimates of resource use in overdiagnosed cases of asthma are necessary to measure the burden of overdiagnosis and to evaluate strategies to reduce this burden. We assessed differences in asthma-related healthcare resource use between patients with a confirmed asthma diagnosis and those with asthma ruled out. DESIGN:Population-based, prospective cohort study. SETTING:Participants were recruited through random-digit dialling of both landlines and mobile phones in the province of British Columbia, Canada. PARTICIPANTS:We included 345 individuals ≥12 years of age with a self-reported physician diagnosis of asthma. The diagnosis of asthma was reassessed at the end of 12 months of follow-up using a structured algorithm, which included a bronchodilator reversibility test, methacholine challenge test, and if necessary medication tapering and a second methacholine challenge test. PRIMARY AND SECONDARY OUTCOME MEASURES:Self-reported annual asthma-related direct healthcare costs (2017 Canadian dollars), outpatient physician visits and medication use from the perspective of the Canadian healthcare system. RESULTS:Asthma was ruled out in 86 (24.9%) participants. The average annual asthma-related direct healthcare costs for participants with confirmed asthma were $C497.9 (SD $C677.9) and for participants with asthma ruled out, $C307.7 (SD $C424.1). In the adjusted analyses, a confirmed diagnosis was associated with higher direct healthcare costs (relative ratio (RR)=1.60, 95% CI 1.14 to 2.22), increased rate of specialist visits (RR=2.41, 95% CI 1.05 to 5.40) and reliever medication use (RR=1.62, 95% CI 1.09 to 2.35), but not primary care physician visits (p=0.10) or controller medication use (p=0.11). CONCLUSIONS:A quarter of individuals with a physician diagnosis of asthma did not have asthma after objective re-evaluation. These participants still consumed a significant amount of asthma-related healthcare resources. The population-level economic burden of asthma overdiagnosis could be substantial.

Project description:IntroductionThe province of British Columbia, Canada, changed the existing oral anhydrous methadone solution to a 10-times more concentrated pre-mixed solution, Methadose®, on February 1, 2014. We aimed to assess the immediate effects of the methadone reformulation on missed doses, days off methadone, changes in medication dosing and dispensations of opioids for pain, and hospitalizations and mortality among all people receiving treatment at or near the time of the change.MethodsWe conducted a population-based retrospective cohort study including all individuals receiving at least one methadone dispensation in the 12 months prior to the study period. We executed a difference-in-differences analysis by estimating a multivariate regression model to compare outcomes in the three months before and after the reformulation (November 1, 2013 to April 30, 2014) versus a time-lagged control cohort with similar characteristics observed during an equivalent nonoverlapping interval. We used daily individual-level linked health administrative data capturing missed doses, days off methadone, changes in methadone dosing, concurrent dispensations of opioids for pain, hospitalizations, and mortality. We stratified the cohorts into three subgroups: (i) those receiving OAT for ≥12 months; (ii) those receiving OAT for <12 months; and (iii) those not receiving OAT at the start of the study period. We conducted sensitivity analyses and placebo tests to assess the robustness of our results.ResultsAmong the 16,339 individuals receiving methadone during the study period, the reformulation was associated with more instances of methadone dose increases (34.5% [95% Confidence Interval (CI): 27.4%, 41.5%]). For those retained in treatment ≥12 months prior to the study period (n = 7449), the reformulation was associated with more instances of methadone dose increases (50.2% [39.5%, 60.8%]) and dispensations of opioids for pain (62.2% [40.8%, 83.5%]), as well as an increase in missed doses (41.9% [29.1%, 54.7%]) and days off methadone (62.6% [39.7%, 85.4%]). We found no statistically significant change in risk of hospitalization or mortality. Sensitivity analyses supported our results.ConclusionOur results reinforce the need expressed by people receiving methadone for greater client involvement in the planning and implementation of regulatory changes that may impact client care, especially those patients with a relatively long treatment history.

Project description:Breast cancer screening programs operate across Canada providing mammography to women in target age groups with the goal of reducing breast cancer mortality through early detection of tumors. Disparities in breast screening participation among socio-demographic groups, including immigrants, have been reported in Canada. Our objectives were to: (1) assess breast screening participation and retention among immigrant and nonimmigrant women in British Columbia (BC), Canada; and (2) to characterize factors associated with screening among screening-age recent immigrant women in BC. We examined 2 population-based cohorts of women eligible for breast screening participation (537 783 women) and retention (281 052 women) using linked health and immigration data. Breast screening rates were presented according to socio-demographic and health-related variables stratified by birth country. Factors associated with screening among recent immigrant women were explored using Poisson regression. We observed marked variation in screening participation across birth country cohorts. Eastern European/Central Asian women showed low participation (37.9%) with rates from individual countries ranging from 35.0% to 49.0%. Participation rates for immigrant women from the most common birth countries, such as China/Macau/Hong Kong/Taiwan (45.7%), India (44.5%), the Philippines (45.9%), and South Korea (39.0%), were lower than the nonimmigrant rates (51.2%). Retention rates showed less variation by birth country; however, some disparities between immigrant and nonimmigrant groups persisted. Associations between screening indicators and study factors varied considerably across immigrant groups. Primary care physician visits were consistently positively associated with screening participation; this variable was also the only predictor associated with screening within each of the groups of recent immigrants. Our study provides unique data on both screening participation and retention among Canadian immigrant women compiled by individual country of birth. Our results are further demonstration that screening disparities exist among immigrant populations as well as in comparison with nonimmigrant women.

Project description:BackgroundThe current study aimed to estimate the prevalence of alcohol use identified as a risk factor during pregnancies by the antenatal care providers, resulting in live births in British Columbia (BC) and to examine associations between alcohol use, adverse neonatal outcomes, and pregnancy complications.MethodsThis population-based cross-sectional study utilized linked obstetrical and neonatal records within the BC Perinatal Data Registry (BCPDR), for deliveries that were discharged between January 1, 2015 and March 31, 2018. The main outcome measures were alcohol use identified as a risk factor during pregnancy, associated maternal characteristics, pregnancy complications, and adverse neonatal outcomes. Estimates for the period and fiscal year prevalence were calculated. Chi-square tests were used to compare adverse neonatal outcomes and pregnancy complications by alcohol use during pregnancy identified as a risk factor. Logistic regression was used to examine the association between alcohol use identified as a risk factor during pregnancy and adverse neonatal outcomes and pregnancy complications, after adjusting for identified risk factors.ResultsA total of 144,779 linked records within the BCPDR were examined. The period prevalence of alcohol use during pregnancy identified as a risk factor was estimated to be 1.1% and yearly prevalence was 1.1, 1.1, 1.3 and 0.9% from the 2014/2015 to 2017/2018 fiscal years, respectively. Alcohol use identified as a risk factor was associated with younger maternal age, fewer antenatal visits, being primiparous, a history of mental illness, substance use and smoking. Neonates with alcohol use during pregnancy identified as a risk factor had greater odds of being diagnosed with: "low birth weight (1000-2499g)" (ICD-10: P07.1; aOR = 1.25; 95% CI: 1.01, 1.53), "other respiration distress of newborn" (ICD-10: P22.8; aOR = 2.57; 95% CI: 1.52, 4.07), "neonatal difficulty in breastfeeding" (ICD-10: P92.5; aOR = 1.97; 95% CI: 1.27, 2.92) and "feeding problems, unspecified" (ICD-10: P92.9; aOR = 2.06; 95% CI: 1.31, 3.09).ConclusionsThe prevalence of alcohol use during pregnancy identified as a risk factor was comparable to previous estimates within the BCPDR. Identified prenatal alcohol exposure was associated with notable differences in maternal and neonatal characteristics and adverse neonatal outcomes. More consistent, thorough screening and prevention efforts targeting alcohol use in pregnancy are urgently needed in Canada.

Dataset Information

Stage, treatment and outcomes for patients with breast cancer in British Columbia in 2002: a population-based cohort study.

Publications

Stage, treatment and outcomes for patients with breast cancer in British Columbia in 2002: a population-based cohort study.

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