Publications by authors named "Claire Holloway"

Preoperative breast magnetic resonance imaging (MRI) is known to detect additional cancers that are occult on mammography and ultrasound. There is debate as to whether these additional lesions affect clinical outcomes. The objective of this systematic review was to summarize the evidence on whether additional information on disease extent obtained with preoperative breast MRI in patients with newly diagnosed breast cancer affects surgical management, rates of recurrence, survival, re-excision, and early detection of bilateral cancer.

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This study measures patient's concordance between clinical reference pathways with survival or cost among a population-based cohort of colon cancer patients applying a continuous measure of concordance. The primary hypothesis is that a higher concordance score with the clinical pathway is significantly associated with longer survival or lower cost. The study informs whether patient's adherence to a defined clinical pathway is beneficial to patients' outcomes or health system.

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Article Synopsis
  • This study examined the recurrence rates of breast cancer among patients in Ontario, Canada, finding that 11.8% developed distant metastasis after primary diagnosis, while 2.4% and 2.3% experienced regional and local recurrences, respectively.* -
  • Patients with distant metastasis had a median overall survival of only 15.4 months, whereas those with locoregional recurrences had a significantly better survival outcome.* -
  • Factors such as advanced cancer stage, higher comorbidity, and symptomatic presentation increased the likelihood of developing distant metastasis, while the use of the drug Trastuzumab significantly reduced the risk of recurrence.*
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Introduction: Older adults with cancer may not receive the same opportunities for treatment as younger patients. In this retrospective population-based cohort study, we explored whether age was an independent predictor of receiving specialist consultation and treatment.

Methods: Patients age 45-99 were identified from the Ontario Cancer Registry having a primary solid tumor diagnosed between 01/Jan/2010 and 31/Dec/2019.

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Breast cancer recurrence is an important outcome for patients and healthcare systems, but it is not routinely reported in cancer registries. We developed an algorithm to identify patients who experienced recurrence or a second case of primary breast cancer (combined as a "second breast cancer event") using administrative data from the population of Ontario, Canada. A retrospective cohort study design was used including patients diagnosed with stage 0-III breast cancer in the Ontario Cancer Registry between 1 January 2009 and 31 December 2012 and alive six months post-diagnosis.

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Clinical pathways are standardized processes that outline the steps required for managing a specific disease. However, patient pathways often deviate from clinical pathways. Measuring the concordance of patient pathways to clinical pathways is important for health system monitoring and informing quality improvement initiatives.

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Article Synopsis
  • In Ontario, breast cancer diagnoses come through various paths, including the Ontario Breast Screening Program (OBSP), primary care providers, or symptomatic presentations; this study aimed to examine how these routes impact aspects like health care use and survival rates.
  • Of the 51,460 patients analyzed, a significant majority (83%) were diagnosed at OBSP-affiliated sites, with those screened by OBSP diagnosed about a month earlier than those who presented symptoms.
  • The findings suggest that being referred to OBSP-affiliated assessment sites is linked to improved overall survival for patients, indicating the importance of the screening program in timely diagnosis and effective care.
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Background: Rates of contralateral prophylactic mastectomy (CPM) are increasing among women with unilateral breast cancer despite low rates of contralateral recurrence and lack of survival benefit. We aimed to investigate the decisional needs and supports required to ensure adequate and quality decision-making by patients with breast cancer facing the decision regarding CPM.

Methods: In this qualitative study, we used semistructured interviews developed with the use of the Ottawa Decision Support Framework to investigate the decisional needs and supports of women (aged > 18 yr) with nonhereditary breast cancer who had previously discussed CPM with their care provider.

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Clinical cancer pathways help standardize healthcare delivery to optimize patient outcomes and health system costs. However, population-level measurement of concordance between standardized pathways and actual care received is lacking. Two measures of pathway concordance were developed for a simplified colon cancer pathway map for Stage II-III colon cancer patients in Ontario, Canada: a cumulative count of concordant events (CCCE) and the Levenshtein algorithm.

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Importance: Esophageal cancer remains one of the most deadly cancers, ranking sixth highest among cancers leading to the greatest years of life lost.

Objective: To determine how patients with esophageal cancer are diagnosed and treated in Ontario's regionalized thoracic surgery centers.

Design, Setting, And Participants: This cohort study included patients diagnosed with esophageal cancer between January 1, 2010, and December 31, 2018, identified from the Ontario Cancer Registry, in a single-payer health care system with regionalization of thoracic surgery in the province of Ontario, Canada.

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Purpose: Provider well-being has become the fourth pillar of the quadruple aim for providing quality care. Exacerbated by the global COVID-19 pandemic, provider well-being has become a critical issue for health care systems worldwide. We describe the prevalence and key system-level drivers of burnout in oncologists in Ontario, Canada.

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There is a global rise in skin cancer incidence, resulting in an increase in patient care needs and healthcare costs. To optimize health care planning, costs, and patient care, Ontario Health developed a provincial skin cancer plan to streamline the quality of care. We conducted a systematic review and a grey literature search to evaluate the definitions and management of skin cancer within other jurisdictions, as well as a provincial survey of skin cancer care practices, to identify care gaps.

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Introduction: Diagnostic assessment programs (DAPs) were implemented in Ontario, Canada, to improve the efficiency of the lung cancer care continuum. We compared the efficiency and effectiveness of care provided to patients in DAPs relative to usual care (non-DAPs).

Methods: Lung cancer patients diagnosed between 2014 and 2016 were identified from the Ontario Cancer Registry.

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Background: Although intracranial metastatic disease (IMD) is a frequent complication of cancer, most cancer registries do not capture these cases. Consequently, a data-gap exists, which thwarts system-level quality improvement efforts. The purpose of this investigation was to determine the real-world burden of IMD.

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Purpose: A prolonged time from first presentation to cancer diagnosis has been associated with worse disease-related outcomes. This study evaluated potential determinants of a long diagnostic interval among symptomatic breast cancer patients.

Methods: This was a population-based, cross-sectional study of symptomatic breast cancer patients diagnosed in Ontario, Canada from 2007 to 2015 using administrative health data.

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Background: The sentinel node biopsy following neoadjuvant chemotherapy (SN FNAC) study has shown that in node-positive (N+) breast cancer, sentinel node biopsy (SNB) can be performed following neoadjuvant chemotherapy (NAC), with a low false negative rate (FNR = 8.4%). A secondary endpoint of the SN FNAC study was to determine whether axillary ultrasound (AxUS) could predict axillary pathological complete response (ypN0) and increase the accuracy of SNB.

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We demonstrate the clinical utility of combining quantitative ultrasound (QUS) imaging of the breast with an artificial neural network (ANN) classifier to predict the response of breast cancer patients to neoadjuvant chemotherapy (NAC) administration prior to the start of treatment. Using a 6 MHz ultrasound system, radiofrequency (RF) ultrasound data were acquired from 100 patients with biopsy-confirmed locally advanced breast cancer prior to the start of NAC. Quantitative ultrasound mean parameter intensity and texture features were computed from the tumour core and margin, and were compared to the clinical/pathological response and 5-year recurrence-free survival (RFS) of patients.

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Background: Contralateral prophylactic mastectomy (CPM) is increasing despite a recent statement from The American Society of Breast Surgeons discouraging average-risk women with unilateral breast cancer (BC) from undergoing CPM. The objective of our study was to conduct a needs assessment of BC health practitioners to gather information about their opinions, attitudes, and experiences surrounding CPM.

Methods: The Ottawa Decision Support Framework was the theoretical framework for the development of the interview guide.

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Purpose: Population-based administrative health care data could be a valuable resource with which to study the cancer diagnostic interval. The objective of the current study was to determine the first encounter in the diagnostic interval and compute that interval in a cohort of patients with breast cancer using an empirical approach.

Methods: This is a retrospective cohort study of patients with breast cancer diagnosed in Ontario, Canada, between 2007 and 2015.

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Objective: The benefit of organized breast assessment on wait times to treatment among asymptomatic women is unknown. The Ontario Breast Screening Program (OBSP) offers screening and organized assessment through Breast Assessment Centres (BAC). This study compares wait times across the treatment pathway among screened women diagnosed with breast cancer through BAC and usual care (UC).

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Purpose: Studies examining symptom differences between surgeries for breast cancer patients rarely incorporate the effects of adjuvant treatment choice. We sought to understand differences in patient-reported symptoms between lumpectomy plus radiation and mastectomy in the year following surgery.

Methods: This cohort study used linked administrative datasets.

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Persistent postsurgical pain is defined as pain localized to the area of surgery of a duration of ≥2 months and is, unfortunately, a common complication after breast cancer surgery. Although there is insufficient evidence to support any preventative strategy, prior literature suggests the possible efficacy of intravenous lidocaine and perioperative pregabalin in preventing persistent pain after surgery. To determine feasibility of conducting a larger definitive trial, we conducted a multicenter 2 × 2 factorial, randomized, placebo-controlled pilot trial of 100 female patients undergoing breast cancer surgery.

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Aim: Breast cancer and its treatment are associated with varying symptoms. The province of Ontario (13.6 million) has implemented a provincial programme to screen for symptoms among cancer patients using the Edmonton Symptom Assessment System (ESAS).

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Purpose: Since 1998, the Ontario Breast Screening Program (OBSP) has offered organized assessment through Breast Assessment Centres (BAC). This study compares survival between screened women diagnosed with breast cancer who have undergone assessment through a BAC and usual care (UC).

Methods: A retrospective design identified two concurrent cohorts of women aged 50 to 69 within the OBSP diagnosed with screen-detected invasive breast cancer at a BAC (n = 2010) and UC (n = 1844) between 2002 and 2010 and followed until 2016.

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Purpose: Mortality reduction attributable to organized breast screening is modest. Screening may be less effective at detecting more aggressive cancers at an earlier stage. This study was conducted to determine the relative efficacy of screening mammography to detect cancers at an earlier stage by molecular phenotype.

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