Kerri Beckmann

Clinical characteristics and outcomes of bilateral breast cancer in an Australian cohort

PURPOSE Uncertainty remains about the impact of bilateral breast cancer. Characteristics and outcomes of unilateral and bilateral breast cancer were compared within an Australian multi-institutional cohort. METHODS Demographic, tumour and treatment characteristics were compared among unilateral (n = 2336) and bilateral cases (52 synchronous, 35 metachronous) using descriptive analyses. Disease-specific outcomes were investigated using Cox regression modelling to adjust for prognostic and treatment factors. RESULTS Factors associated with increased risk of bilateral breast cancer included lobular histology (p = 0.046), family history (p = 0.025) and metropolitan residence (p = 0.006). Mastectomy was more common for bilateral cases (p = 0.001) while radiotherapy was less common (p = 0.015). Index metachronous cases were less likely to receive hormonal therapy (p = 0.001). Five-year survivals for metachronous, synchronous and unilateral cases were 79%, 88% and 94%, respectively. Poorer outcomes remained after adjusting for prognostic factors [HR = 2.26, 1.21-4.21]. CONCLUSION Our results confirm international findings indicating worse outcomes from bilateral compared with unilateral breast cancer.

Exploring the epidemiological characteristics of cancers of unknown primary site in an Australian population: implications for research and clinical care

Objectives: To investigate incidence, mortality and case survival trends for cancer of unknown primary site (CUP) and consider clinical implications.

Surgical margins and risk of locoregional recurrence in invasive breast cancer: An analysis of 10-year data from the breast cancer treatment quality assurance project

AIM There is debate as to what constitutes an adequate excision margin to reduce the risk of locoregional recurrence (LRR) after breast cancer surgery. We have investigated the relationship between surgical margin distance and LRR in women with invasive breast cancer (IBC). METHODS Tumour free margin distances were extracted from histopathology reports for women with IBC, treated by either breast conserving surgery or mastectomy, enrolled in the Breast Cancer Treatment Group Quality Assurance Project from July 1997 to June 2007. Cox proportional hazards regression analyses were conducted to compare the risk of LRR for involved margins compared with negative margins, measured in increments rounded to the nearest mm. RESULTS 88 of 2300 patients (3.8%) experienced an LRR after a mean follow-up of 7.9 years. An involved margin, or a margin of 1 mm was associated with an increased risk of LRR (HR 2.72, 95% CI 1.30-5.69), whilst margin distances of 2 mm or greater were not. Risk of LRR with margin distances <2 mm was particularly high amongst those not receiving radiotherapy (RT). CONCLUSION Based on our findings, we recommend that a tumour free margin distance of 2 mm be adopted as an adequate margin of excision for IBC, in the setting of patients receiving standard adjuvant RT and adjuvant drug therapies as dictated by the current clinical treatment paradigms.

Treatment patterns among colorectal cancer patients in South Australia: a demonstration of the utility of population-based data linkage

Rationale, aims and objectives Population level data on colorectal cancer (CRC) management in Australia are lacking. This study assessed broad level patterns of care and concordance with guidelines for CRC management at the population level using linked administrative data from both the private and public health sectors across South Australia. Disparities in CRC treatment were also explored. Method Linking information from the South Australian Cancer Registry, hospital separations, radiotherapy services and hospital-based cancer registry systems provided data on the socio-demographic, clinical and treatment characteristics for 4641 CRC patients, aged 50–79 years, diagnosed from 2003 to 2008. Factors associated with receiving site/stage-specific treatments (surgery, chemotherapy and radiotherapy) and overall concordance with treatment guidelines were identified using Poisson regression analysis. Results About 83% of colon and 56% of rectal cancer patients received recommended treatment. Provision of neo-adjuvant/adjuvant therapies may be less than optimal. Radiotherapy was less likely among older patients (prevalence ratio 0.7, 95% confidence interval 0.5–0.8). Chemotherapy was less likely among older patients (0.7, 0.6–0.8), those with severe or multiple co-morbidities (0.8, 0.7–0.9), and those from rural areas (0.9, 0.8–1.0). Overall discordance with treatment guidelines was more likely among rectal cancer patients (3.0, 2.7–3.3), older patients (1.6, 1.4–1.8), those with multiple co-morbid conditions (1.3, 1.1–1.4), and those living in rural areas (1.2, 1.0–1.3). Conclusions Greater emphasis should be given to ensure CRC patients who may benefit from neo-adjuvant/adjuvant therapies have access to these treatments.RATIONALE, AIMS AND OBJECTIVES Population level data on colorectal cancer (CRC) management in Australia are lacking. This study assessed broad level patterns of care and concordance with guidelines for CRC management at the population level using linked administrative data from both the private and public health sectors across South Australia. Disparities in CRC treatment were also explored. METHOD Linking information from the South Australian Cancer Registry, hospital separations, radiotherapy services and hospital-based cancer registry systems provided data on the socio-demographic, clinical and treatment characteristics for 4641 CRC patients, aged 50-79 years, diagnosed from 2003 to 2008. Factors associated with receiving site/stage-specific treatments (surgery, chemotherapy and radiotherapy) and overall concordance with treatment guidelines were identified using Poisson regression analysis. RESULTS About 83% of colon and 56% of rectal cancer patients received recommended treatment. Provision of neo-adjuvant/adjuvant therapies may be less than optimal. Radiotherapy was less likely among older patients (prevalence ratio 0.7, 95% confidence interval 0.5-0.8). Chemotherapy was less likely among older patients (0.7, 0.6-0.8), those with severe or multiple co-morbidities (0.8, 0.7-0.9), and those from rural areas (0.9, 0.8-1.0). Overall discordance with treatment guidelines was more likely among rectal cancer patients (3.0, 2.7-3.3), older patients (1.6, 1.4-1.8), those with multiple co-morbid conditions (1.3, 1.1-1.4), and those living in rural areas (1.2, 1.0-1.3). CONCLUSIONS Greater emphasis should be given to ensure CRC patients who may benefit from neo-adjuvant/adjuvant therapies have access to these treatments.

A novel case–control design to estimate the extent of over-diagnosis of breast cancer due to organised population-based mammography screening

Debate about the extent of breast cancer over‐diagnosis due to mammography screening has continued for over a decade, without consensus. Estimates range from 0 to 54%, but many studies have been criticized for having flawed methodology. In this study we used a novel study design to estimate over‐diagnosis due to organised mammography screening in South Australia (SA). To estimate breast cancer incidence at and following screening we used a population‐based, age‐matched case–control design involving 4,931 breast cancer cases and 22,914 controls to obtain OR for yearly time intervals since womens last screening mammogram. The level of over‐diagnosis was estimated by comparing the cumulative breast cancer incidence with and without screening. The former was derived by applying ORs for each time window to incidence rates in the absence of screening, and the latter, by projecting pre‐screening incidence rates. Sensitivity analyses were undertaken to assess potential biases. Over‐diagnosis was estimated to be 8% (95%CI 2–14%) and 14% (95%CI 8–19%) among SA women aged 45 to 85 years from 2006–2010, for invasive breast cancer and all breast cancer respectively. These estimates were robust when applying various sensitivity analyses, except for adjustment for potential confounding assuming higher risk among screened than non‐screened women, which reduced levels of over‐diagnosis to 1% (95%CI 5–7%) and 8% (95%CI 2–14%) respectively when incidence rates for screening participants were adjusted by 10%. Our results indicate that the level of over‐diagnosis due to mammography screening is modest and considerably lower than many previous estimates, including others for Australia.

Estimates of over-diagnosis of breast cancer due to population-based mammography screening in South Australia after adjustment for lead time effects.

Objective To estimate over-diagnosis due to population-based mammography screening using a lead time adjustment approach, with lead time measures based on symptomatic cancers only. Subjects Women aged 40–84 in 1989–2009 in South Australia eligible for mammography screening. Methods Numbers of observed and expected breast cancer cases were compared, after adjustment for lead time. Lead time effects were modelled using age-specific estimates of lead time (derived from interval cancer rates and predicted background incidence, using maximum likelihood methods) and screening sensitivity, projected background breast cancer incidence rates (in the absence of screening), and proportions screened, by age and calendar year. Results Lead time estimates were 12, 26, 43 and 53 months, for women aged 40–49, 50–59, 60–69 and 70–79 respectively. Background incidence rates were estimated to have increased by 0.9% and 1.2% per year for invasive and all breast cancer. Over-diagnosis among women aged 40–84 was estimated at 7.9% (0.1–12.0%) for invasive cases and 12.0% (5.7–15.4%) when including ductal carcinoma in-situ (DCIS). Conclusions We estimated 8% over-diagnosis for invasive breast cancer and 12% inclusive of DCIS cancers due to mammography screening among women aged 40–84. These estimates may overstate the extent of over-diagnosis if the increasing prevalence of breast cancer risk factors has led to higher background incidence than projected.

Clinical and socio‐demographic profile of an Australian multi‐institutional prostate cancer cohort

Aims:  To describe the clinical and socio‐demographic data from a South Australian prostate cancer cohort (PCCOD).

Do breast cancer risk factors differ among those who do and do not undertake mammography screening

Objectives There is considerable interest in whether mammography screening leads to over-diagnosis of breast cancer. However self-selection into screening programmes may lead to risk differences that affect estimates of over-diagnosis. This study compares the breast cancer risk profiles of participants and non-participants of population-based mammography screening. Risk profiles are also compared between those who have and have not used private screening services. Setting This study involved 1162 women aged 40–84 who participated in the 2012 Health Omnibus, an annual face-to-face interview-based survey of a representative sample of the population in the state of South Australia. Methods Data were collected on participation in mammography screening, demographic characteristics and breast cancer risk factors (including reproductive, familial and lifestyle factors). Missing data were multiply imputed. Factors independently associated with ever having been screened were identified using multivariable logistic regression, for population-based and ad hoc, private mammography screening separately. Results Compared with non-participants, participants of population-based screening were more likely to have used hormone replacement therapy (odds ratio [OR] = 3.72), experienced breast biopsy or surgery (OR = 2.22), and be overweight or obese (OR = 1.57). They were less likely to be sufficiently active (OR = 0.57) or be born in a non-English speaking country (OR = 0.50) or aged under 50 (OR = 0.09). Women who were screened privately were more likely to have a family history of breast cancer (OR = 1.66) and have experienced breast biopsy or surgery (OR = 3.17) than those who had not. Conclusions South Australian women who participated in the population-based mammography screening have a slightly higher prevalence of breast cancer risk factors. This also applies to those who undertook private screening.

Effects of variations in hysterectomy status on population coverage by cervical screening

Objectives: To investigate geographic differences in hysterectomy rates and effects on estimated screening coverage in South Australia.

Tools for predicting patient-reported outcomes in prostate cancer patients undergoing radical prostatectomy: a systematic review of prognostic accuracy and validity

Background:Radical prostatectomy is a common surgical procedure performed to treat prostate cancer. Patient-reported outcomes after surgery include urinary incontinence, erectile dysfunction, decreased quality of life and psychological effects. Predictive tools to assess the likelihood of an individual experiencing various patient-reported outcomes have been developed to aid decision-making when selecting treatment.Methods:A systematic review was undertaken to identify all papers describing tools for the prediction of patient-reported outcome measures in men with prostate cancer treated with radical prostatectomy. To be eligible for inclusion, papers had to provide a summary measure of accuracy. PubMed and EMBASE were searched from July 2007. Title/abstract screening, and full-text review were undertaken by two reviewers, while data extraction and critical appraisal was performed by a single reviewer.Results:The search strategy identified 3217 potential studies, of which 191 progressed to full-text review and 14 were included. From these studies, 27 tools in total were identified, of which 18 predicted urinary symptoms, six predicted erectile function and one predicted freedom from a group of three outcomes (‘trifecta’) (biochemical recurrence, incontinence and erectile dysfunction). On the basis of tool accuracy (>70%) and external validation, two tools predicting incontinence and two tools predicting erectile dysfunction are ready for implementation.Conclusions:A small number of tools for the prediction of patient-reported outcomes following radical prostatectomy have been developed. Four tools were found to have adequate accuracy and validation and are ready for implementation for the prediction of urinary incontinence and erectile dysfunction.