The Impact of Rurality and Disadvantage on the Diagnostic Interval for Breast Cancer in a Large Population-Based Study of 3202 Women in Queensland, Australia

Individual and area level factors associated with the breast cancer diagnostic-treatment interval in Queensland, Australia

BACKGROUND

Delays to breast cancer treatment can lead to more aggressive and extensive treatments, increased expenses, increased psychological distress, and poorer survival. We explored the individual and area level factors associated with the interval between diagnosis and first treatment in a population-based cohort in Queensland, Australia.

METHODS

Data from 3216 Queensland women aged 20 to 79, diagnosed with invasive breast cancer (ICD-O-3 C50) between March 2010 and June 2013 were analysed. Diagnostic dates were sourced from the Queensland Cancer Registry and treatment dates were collected via self-report. Diagnostics-treatment intervals were modelled using flexible parametric survival methods.

RESULTS

The median interval between breast cancer diagnosis and first treatment was 15 days, with an interquartile range of 9-26 days. Longer diagnostic-treatment intervals were associated with a lack of private health coverage, lower pre-diagnostic income, first treatments other than breast conserving surgery, and residence outside a major city. The model explained a modest 13.7% of the variance in the diagnostic-treatment interval [Formula: see text]. Sauerbrei's D was 0.82, demonstrating low to moderate discrimination performance.

CONCLUSION

Whilst this study identified several individual- and area-level factors associated with the time between breast cancer diagnosis and first treatment, much of the variation remained unexplained. Increased socioeconomic disadvantage appears to predict longer diagnostic-treatment intervals. Though some of the differences are small, many of the same factors have also been linked to screening and diagnostic delay. Given the potential for accumulation of delay at multiple stages along the diagnostic and treatment pathway, identifying and applying effective strategies address barriers to timely health care faced by socioeconomically disadvantaged women remains a priority.

Improving Time to Diagnostic Resolution in the Breast Imaging Service: A Tertiary Center's Experience and Process of Improvement

OBJECTIVE

Breast imaging services often experience a significant degree of variability in patient flow, leading to delay in time to diagnostic resolution, commonly referred to as time to resolution (TTR). This study applies Lean Six Sigma Methodology (LSSM) to reduce TTR and enhance patient outcomes.

METHODS

This study was IRB-approved. A baseline audit was done using cases of mammographic recalls (BI-RADS 0) to measure baseline TTR. Multidisciplinary meetings with all members of the breast imaging service, alongside a study of patient complaint data, were utilized to identify issues that were causing prolonged TTR. Following that, possible solutions were proposed and implemented. A post-implementation audit was conducted, and the resulting TTRs were compared. Significant differences in TTR between the pre- and post-solution implementation were assessed using the Mann-Whitney U test.

RESULTS

During the baseline audit of 8 months, 589 cases of mammographic recalls (BI-RADS 0) were identified, and the resulting average TTR was 86.3 days. During the post-implementation period of 3 months, 370 mammographic recalls (BI-RADS 0) occurred, with a resulting average TTR of 36.0 days. After applying LSSM, TTR was reduced by 58.3% (P < 0.01). Some changes implemented included training the coordinators, establishing a rapid diagnostic clinic using previously underutilized equipment, and having radiologists assigned full-time to the breast imaging service.

CONCLUSION

Our team has successfully managed to identify various causes behind the prolonged TTR using LSSM. Team collaboration was essential to study and decide on a more achievable TTR.

Severity and risk factors of interval breast cancer in Queensland, Australia: a population-based study

BACKGROUND

Interval breast cancers (BC) are those diagnosed within 24 months of a negative mammogram. This study estimates the odds of being diagnosed with high-severity BC among screen-detected, interval, and other symptom-detected BC (no screening history within 2 years); and explores factors associated with being diagnosed with interval BC.

METHODS

Telephone interviews and self-administered questionnaires were conducted among women (n = 3,326) diagnosed with BC in 2010-2013 in Queensland. Respondents were categorised into screen-detected, interval, and other symptom-detected BCs. Data were analysed using logistic regressions with multiple imputation.

RESULTS

Compared with screen-detected BC, interval BC had higher odds of late-stage (OR = 3.50, 2.9-4.3), high-grade (OR = 2.36, 1.9-2.9) and triple-negative cancers (OR = 2.55, 1.9-3.5). Compared with other symptom-detected BC, interval BC had lower odds of late stage (OR = 0.75, 0.6-0.9), but higher odds of triple-negative cancers (OR = 1.68, 1.2-2.3). Among women who had a negative mammogram (n = 2,145), 69.8% were diagnosed at their next mammogram, while 30.2% were diagnosed with an interval cancer. Those with an interval cancer were more likely to have healthy weight (OR = 1.37, 1.1-1.7), received hormone replacement therapy (2-10 years: OR = 1.33, 1.0-1.7; > 10 years: OR = 1.55, 1.1-2.2), conducted monthly breast self-examinations (BSE) (OR = 1.66, 1.2-2.3) and had previous mammogram in a public facility (OR = 1.52, 1.2-2.0).

CONCLUSION

These results highlight the benefits of screening even among those with an interval cancer. Women-conducted BSE were more likely to have interval BC which may reflect their increased ability to notice symptoms between screening intervals.

Assurance of Timely Access to Breast Cancer Diagnosis and Treatment by a Regional Breast Health Clinic Serving Both Urban and Rural-Remote Communities

In response to breast cancer diagnostic regional wait times exceeding both national and provincial standards and to symptomatic patient referrals for diagnostic mammography taking longer than abnormal screening mammography referrals, the Rae Fawcett Breast Health Clinic (RFBHC) was opened in 2017 in a mid-sized Canadian hospital serving both urban and rural-remote communities. We investigated whether the RFBHC improved wait times to breast cancer diagnosis, improved compliance with national and provincial breast cancer standards, and decreased the wait time disparity associated with referral source. Statistical analyses of wait time differences were conducted between patients who were diagnosed with breast cancer prior to and after the RFBHC establishment. Study group compliance with national and provincial standards and wait time differences by referral source were also analysed. A survey was administered to assess overall patient experience with the RFBHC and clinic wait times. RFBHC patients had a shorter mean wait to breast cancer diagnosis (24.4 vs. 45.7 days, p ≤ 0.001) and a shorter mean wait to initial breast cancer treatment (49.1 vs. 78.9 days, p ≤ 0.001) than pre-RFBHC patients. After the RFBHC establishment, patients who attended the RFBHC had a shorter mean wait time to breast cancer diagnosis (24.4 vs. 36.9 days, p = 0.005) and to initial treatment (49.1 vs. 73.1 days, p ≤ 0.001) than patients who did not attend the clinic. Compliance with national and provincial breast cancer standards improved after the RFBHC establishment and the wait time disparity between screening mammography referrals and symptomatic patient referrals decreased. Survey results indicate that the RFBHC is meeting patient expectations. We concluded that the establishment of a breast health clinic in a Canadian center serving urban and rural-remote communities improved breast diagnostic services.

A prognostic survival model for women diagnosed with invasive breast cancer in Queensland, Australia

PURPOSE

Prognostic models can help inform patients on the future course of their cancer and assist the decision making of clinicians and patients in respect to management and treatment of the cancer. In contrast to previous studies considering survival following treatment, this study aimed to develop a prognostic model to quantify breast cancer-specific survival at the time of diagnosis.

METHODS

A large (n = 3323), population-based prospective cohort of women were diagnosed with invasive breast cancer in Queensland, Australia between 2010 and 2013, and followed up to December 2018. Data were collected through a validated semi-structured telephone interview and a self-administered questionnaire, along with data linkage to the Queensland Cancer Register and additional extraction from medical records. Flexible parametric survival models, with multiple imputation to deal with missing data, were used.

RESULTS

Key factors identified as being predictive of poorer survival included more advanced stage at diagnosis, higher tumour grade, "triple negative" breast cancers, and being symptom-detected rather than screen detected. The Harrell's C-statistic for the final predictive model was 0.84 (95% CI 0.82, 0.87), while the area under the ROC curve for 5-year mortality was 0.87. The final model explained about 36% of the variation in survival, with stage at diagnosis alone explaining 26% of the variation.

CONCLUSIONS

In addition to confirming the prognostic importance of stage, grade and clinical subtype, these results highlighted the independent survival benefit of breast cancers diagnosed through screening, although lead and length time bias should be considered. Understanding what additional factors contribute to the substantial unexplained variation in survival outcomes remains an important objective.

BC-DETECT: combined detection of serum HE4 and TFF3 improves breast cancer diagnostic efficacy

BACKGROUND

Early accurate breast cancer (BC) diagnosis is critical in disease management. Mammography has been widely used. However, its radiation, and high false-negative and -positive results have always been a concern. We evaluated combined detection of human epididymal protein 4 (HE4) and trefoil factor 3 (TFF3) as substitute method to enhance BC diagnosis.

METHODS

HE4 and TFF3 blood levels were determined by ELISA in sera of 120 BC patients and 80 women (40 healthy and 40 benign breast disease) as controls. Receiver-operating characteristic curve was applied for evaluation diagnostic power of each biomarker and their combination.

RESULTS

In BC patients, serum HE4 [5 (2-11.9) vs. 3.1 (1.8-5.4) and 1 (1-3.5); P = 0.022] and TFF3 [5.3 (4.5-6.7) vs. 4.7 (4-4.8) and 3.9 (3-4.4); P = 0.027] were significantly higher than that in benign and healthy groups, respectively. Both HE4 (AUC = 0.783; P < 0.0001) and TFF3 (AUC = 0.759; P < 0.0001) had superior BC diagnostic ability compared to CEA and CA-15.3. Logistic regression analysis revealed simplified index BC-DETECT = HE4 + TFF3, and its values were significantly (P = 0.0132) elevated in BC (10.9 (8.4-17.2) compared to benign (7.2 (5.4-10.1)) and healthy (5.1 (4-6.3)) controls. AUC of BC-DETECT for BC prediction was (AUC = 0.850; P < 0.0001) with sensitivity, specificity, and positive and negative predictive values and accuracy of 84.2%, 70%, 80.8%, 74.7%, and 78.5%, respectively. High BC-DETECT levels were associated with tumor non-luminal subtypes, late stage, high grade, large size, lymph-node invasion, and multiple lesions.

CONCLUSIONS

BC-DETECT is inexpensive, rapid, and easy to perform and reliably guides BC early detection. Moreover, the association between elevated BC-DETECT values and disease severity may propose its potential role as prognostic marker.

Trends in surgery and adjuvant treatment for early-stage breast cancer: a population-based study in Queensland, Australia

PURPOSE

Our aim was to describe variations in the treatment of early-stage breast cancer and to examine factors associated with disease-specific survival (DSS).

METHODS

The study used linked data for 24,190 women with a T1 (≤ 20 mm) breast cancer who underwent surgery from 2005 to 2019. Multivariate logistic regression was used to model predictors of receiving breast-conserving surgery (BCS) compared to mastectomy and a multinomial model was used to examine factors associated with type(s) of treatment received.

RESULTS

Overall, 70.3% had BCS, with a reduced likelihood of BCS observed for younger women (p < 0.001), rural residence, (p < 0.001), socioeconomic disadvantage (p = 0.004), higher tumour grade (p < 0.001) and surgery in a public versus private hospital (p < 0.001). Compared to women who received BCS and radiation therapy (RT), those having mastectomy alone or mastectomy plus RT were more likely to be younger (p < 0.001), live in a rural area (p < 0.001), have higher-grade tumours (p < 0.001) and positive lymph nodes (p < 0.001). Overall 5-year survival was 95.3% and breast cancer-specific survival was 98.3%. Highest survival was observed for women having BCS and RT and lowest for those having mastectomy and RT (p < 0.001).

CONCLUSION

Our results indicate some variation in the management of early-stage breast cancer. Lower rates of BCS were observed for rural and disadvantaged women and for those treated in a public or low-volume hospital. Whilst survival was high for this cohort, differences in tumour biology likely explain the differences in survival according to treatment type.

Dietary and physical activity changes and adherence to WCRF/AICR cancer prevention recommendations following a remotely delivered weight loss intervention for female breast cancer survivors: The Living Well after Breast Cancer randomized controlled trial

BACKGROUND

Diet, exercise, and weight management are key in improving outcomes for breast cancer survivors, with international recommendations for cancer survivors relating to these behaviors. However, few behavioral interventions have reported outcomes aligned specifically with these recommendations.

OBJECTIVE

To evaluate a remotely delivered weight loss intervention versus usual care for female breast cancer survivors, on changes in multiple diet and physical activity behaviors.

DESIGN

A randomized controlled trial with assessments at study baseline, 6-, 12- and 18 months (i.e., mid-intervention, post-intervention, and non-contact follow-up).

PARTICIPANTS/SETTING

Participants were recruited between October 2012 and December 2014 through hospitals in Brisbane (Australia) and the state-based cancer registry. Eligible participants (female, 18-75 years, BMI 25-45 kg/m², diagnosed with stage I-III breast cancer in previous two years) were randomly allocated to intervention (n=79) or usual care (n=80).

INTERVENTION

Participants randomized to the intervention group received 22 counseling telephone calls targeting diet and physical activity aimed at achieving 5-10% weight loss, and optional text messages, over 12 months. Usual care participants received their standard medical care and brief feedback following each assessment, which was similar to that provided to intervention participants with the exception that usual care participants' results were not compared to national and study recommendations.

MAIN OUTCOME MEASURES

Dietary intake (24-hour recalls); physical activity (hip-worn Actigraph); sitting time (thigh-worn activPAL3); and, adherence to World Cancer Research Fund/American Cancer Research Institute (WCRF/AICR) recommendations for cancer survivors (0-7 score) were measured at each assessment, with data collected between November 2012 and October 2016.

STATISTICAL ANALYSES PERFORMED

Intervention effects were assessed by linear mixed models, accounting for repeated measures and baseline values. Significance was set at P<0.05.

RESULTS

At baseline, participants were (mean±SD) aged 55±9 years, with a BMI of 31.4±5.0 kg/m², 10.7±5.0 months post-diagnosis, and primarily non-minority. At baseline, only 8% (n=12) of participants met ≥5/7 WCRF/AICR recommendations (mean±SD WCRF/AICR adherence score: 3.8±1.0). At 12 months, significant intervention effects were observed in walking/running ( +21 mins/week; 95%CI: 4, 38) and WCRF/AICR adherence scores (+0.3 points; 95%CI: 0.0, 0.6) only. At 18 months, significant intervention effects were observed for energy intake (-229 kcal/day energy; 95%CI: -373, -84), total fat (-10 g/day; 95%CI: -18, -2), and saturated fat (-5 g/day; 95%CI: -9, -1), and were sustained for WCRF/AICR adherence scores (+0.5 points; 95%CI: 0.2, 0.8).

CONCLUSIONS

This remotely delivered weight loss intervention led to sustained improvements in WCRF/AICR adherence scores, and some improvements in diet and physical activity. These findings provide support for the health benefit of programs targeting lifestyle behaviors in line with cancer survivor recommendations, and the potential for dissemination of such programs following treatment for early-stage female breast cancer.

Conceptual Framework to Guide Early Diagnosis Programs for Symptomatic Cancer as Part of Global Cancer Control

Diagnosing cancer earlier can enable timely treatment and optimize outcomes. Worldwide, national cancer control plans increasingly encompass early diagnosis programs for symptomatic patients, commonly comprising awareness campaigns to encourage prompt help-seeking for possible cancer symptoms and health system policies to support prompt diagnostic assessment and access to treatment. By their nature, early diagnosis programs involve complex public health interventions aiming to address unmet health needs by acting on patient, clinical, and system factors. However, there is uncertainty regarding how to optimize the design and evaluation of such interventions. We propose that decisions about early diagnosis programs should consider four interrelated components: first, the conduct of a needs assessment (based on cancer-site-specific statistics) to identify the cancers that may benefit most from early diagnosis in the target population; second, the consideration of symptom epidemiology to inform prioritization within an intervention; third, the identification of factors influencing prompt help-seeking at individual and system level to support the design and evaluation of interventions; and finally, the evaluation of factors influencing the health systems' capacity to promptly assess patients. This conceptual framework can be used by public health researchers and policy makers to identify the greatest evidence gaps and guide the design and evaluation of local early diagnosis programs as part of broader cancer control strategies.

Factors associated with being diagnosed with high severity of breast cancer: a population-based study in Queensland, Australia

PURPOSE

This study explores factors that are associated with the severity of breast cancer (BC) at diagnosis.

METHODS

Interviews were conducted among women (n = 3326) aged 20-79 diagnosed with BC between 2011 and 2013 in Queensland, Australia. High-severity cancers were defined as either Stage II-IV, Grade 3, or having negative hormone receptors at diagnosis. Logistic regression models were used to estimate odds ratios (ORs) of high severity BC for variables relating to screening, lifestyle, reproductive habits, family history, socioeconomic status, and area disadvantage.

RESULTS

Symptom-detected women had greater odds (OR 3.38, 2.86-4.00) of being diagnosed with high-severity cancer than screen-detected women. Women who did not have regular mammograms had greater odds (OR 1.78, 1.40-2.28) of being diagnosed with high-severity cancer than those who had mammograms biennially. This trend was significant in both screen-detected and symptom-detected women. Screen-detected women who were non-smokers (OR 1.77, 1.16-2.71), postmenopausal (OR 2.01, 1.42-2.84), or employed (OR 1.46, 1.15-1.85) had greater odds of being diagnosed with high-severity cancer than those who were current smokers, premenopausal, or unemployed. Symptom-detected women being overweight (OR 1.67, 1.31-2.14), postmenopausal (OR 2.01, 1.43-2.82), had hormone replacement therapy (HRT) < 2 years (OR 1.60, 1.02-2.51) had greater odds of being diagnosed with high-severity cancer than those of healthy weight, premenopausal, had HRT > 10 years.

CONCLUSION

Screen-detected women and women who had mammograms biennially had lower odds of being diagnosed with high-severity breast cancer, which highlighted the benefit of regular breast cancer screening. Women in subgroups who are more likely to have more severe cancers should be particularly encouraged to participate in regular mammography screening.

Nonbreast cancer incidence, treatment received and outcomes: Are there differences in breast screening attendees versus nonattendees?

While reductions in breast cancer mortality have been evident since the introduction of population-based breast screening in women aged 50-74 years, participation in cancer screening programs can be influenced by several factors, including health system and those related to the individual. In our study, we compared cancer incidence and mortality for several cancer types other than breast cancer, noncancer mortality and patterns of treatment amongst women who did and did not participate in mammography screening. All women aged 50-65 years enrolled on the Queensland Electoral Roll in 2000 were included. The study population was then linked to records from the population-based breast screening program and private fee-for-service screening options to establish screened and unscreened cohorts. Diagnostic details for selected cancers and cause of death were obtained from the Queensland Oncology Repository. We calculated incidence rate ratios and hazard ratios comparing screened and unscreened cohorts. Among screened compared to unscreened women, we found a lower incidence of cancers of the lung, cervix, head and neck and esophagus and an increase in colorectal cancers. Cancer mortality (excluding breast cancer) was 35% lower among screened compared to unscreened women and they were also about 23% less likely to be diagnosed with distant disease. Screened compared to unscreened women were more likely to receive surgery and less likely to receive no treatment. Our study adds further to the population data examining outcomes among women participating in mammography screening.

The Importance of Place of Residence on Hospitalized Outcomes for Severely Injured Trauma Patients: A Trauma Registry Analysis

PURPOSE

Socioecological factors are understudied in relation to trauma patients' outcomes. This study investigated the association of neighborhood socioeconomic disadvantage (SED) and remoteness of residence on acute length of hospital stay days (ALSD) and inpatient mortality.

METHODS

A retrospective cohort study was conducted on adults hospitalized for major trauma in a Level 1 trauma center in southeast Queensland from 2014 to 2017. Neighborhood SED and remoteness indices were linked to individual patient variables. Step-wise multivariable negative binomial regression and proportional hazards regression analyses were undertaken, adjusting for injury and patient factors. Outcomes were ALSD and inpatient mortality.

FINDINGS

We analyzed 1,025 patients. Statistically significant increased hazard of inpatient mortality was found for older age (HR 3.53, 95% CI: 1.77-7.11), injury severity (HR 5.27, 95% CI: 2.78-10.02), remoteness of injury location (HR 1.75, 95% CI: 1.06-2.09), and mechanisms related to intentional self-harm or assault (HR 2.72, 95% CI: 1.48-5.03,). Excess mortality risk was apparent for rural patients sustaining less severe injuries (HR 4.20, 95% CI: 1.35-13.10). Increased risk for longer ALSD was evident for older age (RR 1.35, 95% CI: 1.07-1.71), head injury (RR 1.39, 95% CI: 1.19-1.62), extremity injuries (RR 1.82, 95% CI: 1.55-2.14), and higher injury severity scores (ISS) (RR 1.51, 95%: CI: 1.29-1.76).

CONCLUSIONS

Severely injured rural trauma patients are more likely to be socioeconomically disadvantaged and sustain injuries predisposing them to worse hospital outcomes. Further research is needed to understand more about care pathways and factors influencing the severity, mechanism and clinical consequences of rural-based traumatic injuries.

Evaluation of a Breastfeeding App in Rural Australia: Prospective Cohort Study

BACKGROUND

New mothers often need support to establish and maintain breastfeeding, and rural women may find it difficult to access breastfeeding resources locally. There are many smartphone applications for breastfeeding mothers; however, very few have been developed by health professionals. We evaluated a smartphone application, Breastfeeding Solutions, developed by U.S. IBCLC Nancy Mohrbacher. Research aims: The aims were (a) to explore usability of the application among rural Australian breastfeeding women and (b) to describe participants' infant feeding outcomes compared with the general population.

METHODS

A prospective longitudinal self-report survey design was used. Data were collected via online questionnaires at baseline and at 3 and 6 months from a convenience sample of new mothers. The setting was southwest Victoria, Australia, from 2016 to 2017. Descriptive statistics were used to answer research aims.

RESULTS

Of the initial 46 participants who received the app, 63% ( n = 29) completed surveys at 3 and 6 months. Usability was assessed at 3 months: 93.5% of participants (29 of 31) rated the application favorably, whereas 96.8% (30 of 31) found the application helpful and 87.1% (27 of 31) would recommend it to other mothers. At the 6-month survey, 79% of participants ( n = 23) were breastfeeding; 10% ( n = 3) had stopped breastfeeding during the first 3 months. The local breastfeeding rate at 6 months was approximately 50% according to routinely collected data; however, we cannot infer that the application was responsible for the difference.

CONCLUSION

The smartphone application was acceptable to breastfeeding women in an Australian rural setting. Further evaluation using a user-centered design could improve rural postpartum women's access to reliable, evidence-based information.

Symptom Signatures and Diagnostic Timeliness in Cancer Patients: A Review of Current Evidence

Early diagnosis is an important aspect of contemporary cancer prevention and control strategies, as the majority of patients are diagnosed following symptomatic presentation. The nature of presenting symptoms can critically influence the length of the diagnostic intervals from symptom onset to presentation (the patient interval), and from first presentation to specialist referral (the primary care interval). Understanding which symptoms are associated with longer diagnostic intervals to help the targeting of early diagnosis initiatives is an area of emerging research. In this Review, we consider the methodological challenges in studying the presenting symptoms and intervals to diagnosis of cancer patients, and summarize current evidence on presenting symptoms associated with a range of common and rarer cancer sites. We propose a taxonomy of cancer sites considering their symptom signature and the predictive value of common presenting symptoms. Finally, we consider evidence on associations between symptomatic presentations and intervals to diagnosis before discussing implications for the design, implementation, and evaluation of public health or health system interventions to achieve the earlier detection of cancer.

Geographical differences in risk of advanced breast cancer: Limited evidence for reductions over time, Queensland, Australia 1997-2014

BACKGROUND

Reducing geographical inequalities in breast cancer stage remains a key focus of public health policy. We explored whether patterns of advanced breast cancer by residential accessibility and disadvantage in Queensland, Australia, have changed over time.

METHODS

Population-based cancer registry study of 38,706 women aged at least 30 years diagnosed with a first primary invasive breast cancer of known stage between 1997 and 2014. Multilevel logistic regression was used to examine temporal changes in associations of area-level factors with odds of advanced disease after adjustment for individual-level factors.

RESULTS

Overall 19,401 (50%) women had advanced breast cancer. Women from the most disadvantaged areas had higher adjusted odds (OR = 1.23 [95%CI 1.13, 1.32]) of advanced disease than those from least disadvantaged areas, with no evidence this association had changed over time (interaction p = 0.197). Living in less accessible areas independently increased the adjusted odds (OR = 1.18 [1.09, 1.28]) of advanced disease, with some evidence that the geographical inequality had reduced over time (p = 0.045). Sensitivity analyses for un-staged cases showed that the original associations remained, regardless of assumptions made about the true stage distribution.

CONCLUSIONS

Both geographical and residential socioeconomic inequalities in advanced stage diagnoses persist, potentially reflecting barriers in accessing diagnostic services. Given the role of screening mammography in early detection of breast cancer, the lack of population-based data on private screening limits our ability to determine overall participation rates by residential characteristics. Without such data, the efficacy of strategies to reduce inequalities in breast cancer stage will remain compromised.