Performance measures from 10 years of breast screening in the Ontario Breast Screening Program, 1990/91 to 2000

Screening behaviours, demographics, and stage at diagnosis in the publicly funded Ontario Breast Screening Program

PURPOSE

The Ontario Breast Screening Program (OBSP) offers free screening mammograms every 2 years, to women aged 50-74. Study objectives were to determine demographic characteristics associated with the adherence to OBSP and if women screened in the OBSP have a lower stage at diagnosis than non-screened eligible women.

METHODS

We used the Ontario cancer registry (OCR) to identify 48,927 women, aged 51-74 years, diagnosed with breast cancer between 2010 and 2017. These women were assigned as having undergone adherent screening (N = 26,108), non-adherent screening (N = 6546) or not-screened (N = 16,273) in the OBSP. We used multinomial logistic regression to investigate the demographic characteristics associated with screening behaviour, as well as the association between screening status and stage at diagnosis.

RESULTS

Among women with breast cancer, those living in rural areas (versus the largest urban areas) had a lower odds of not being screened (odds ratio [OR] 0.73, 95% confidence interval [CI] 0.68, 0.78). Women in low-income (versus high-income) communities were more likely not to be screened (OR 1.42, 95% CI 1.33, 1.51). When stratified, the association between income and screening status only held in urban areas. Non-screened women were more likely to be diagnosed with stage II (OR 1.91, 95% CI 1.82, 2.01), III (OR 2.96, 95% CI 2.76, 3.17), or IV (OR 8.96, 95% CI 7.94, 10.12) disease compared to stage I and were less likely to be diagnosed with ductal carcinoma in situ (DCIS) (OR 0.91, 95% CI 0.84-0.98).

CONCLUSIONS

This study suggests that targeting OBSP recruitment efforts to lower income urban communities could increase screening rates. OBSP adherent women were more likely to be diagnosed with earlier stage disease, supporting the value of this initiative and those like it.

Periodic screening for breast and cervical cancer in women with diabetes: a population-based cohort study

PURPOSE

Diabetes is associated with poorer cancer outcomes. Screening for breast and cervical cancer is recommended by clinical guidelines; however, utilization of these tests in people with diabetes has been unclear due to methodological limitations in the evidence base. We used administrative data to determine the association between diabetes and the rates of becoming up-to-date with periodic breast and cervical cancer screening over a 20-year period.

METHODS

Healthcare databases from Ontario, Canada, were linked to assemble two population-based cohorts of 50-70 and 21-70 year-olds between 1994 and 2011, eligible for breast and cervical cancer screening, respectively. Using age as the time scale, multivariable recurrent events models were implemented to examine the association between the presence of diabetes and the rates of becoming up-to-date with the recommended cancer screenings.

RESULTS

In each of the breast and cervical cancer screening cohorts, there were, respectively, 1,516,302 (16% had diabetes at baseline) and 4,751,220 (9.5% had diabetes at baseline) screen-eligible women. In multivariable models, prevalent diabetes (duration ≥ 2 years) was associated with lower rates of becoming up-to-date with cervical (hazard ratio, HR 0.85, 95% confidence interval, CI 0.84-0.85) and breast (HR 0.94, CI 0.93-0.94) cancer screening, compared to no diabetes.

CONCLUSIONS

Having diabetes is associated with decreased rates of becoming up-to-date with two recommended periodic cancer screenings, with a bigger reduction in the rates of becoming up-to-date with cervical cancer screening. Greater attention to cervical cancer preventive services is needed in women with diabetes.

The roles of clinical audit and test sets in promoting the quality of breast screening: a scoping review

Breast screening programmes enhance the probability of early breast cancer detection in many countries worldwide; however, the success of these efforts is highly dependent on the ability of breast screen readers to detect abnormalities in the screened population, which has low prevalence. Therefore, this task can be challenging. Clinical audit is a key quality assurance measure that aims to keep the screen reading performance within acceptable standards. Auditing, nonetheless, is a lengthy process, and its accuracy is dependent on available clinical data, which often can be limited. Mammographic standardised test sets are a different screen reading evaluation approach that provides participants with instant feedback based on a simulated environment. Although a test set provides unique evaluative qualities, its ability to represent clinical performance is debated. This article describes the distinctive roles of clinical audit and test sets in measuring and improving the quality of breast screening and highlights the relationship between test sets and clinical performance.

Importance of quality in breast cancer screening practice - a natural experiment in Alberta, Canada

OBJECTIVES

Regular breast cancer screening is a widely used cancer prevention strategy. Important quality indicators of screening include cancer detection rate, false positive rate, benign biopsy rate and post-screen invasive cancer rate. We compared quality indicators of community radiology clinics to those of 'Screen Test', which feature centralised batch reading and quality control processes. Both types of providers operated under a single provincial Breast Cancer Screening Programme.

SETTING

Community radiology clinics are operated by independent fee-for-service radiologists serving large and small communities throughout the Canadian province of Alberta. Launched by the provincial cancer agency, the Screen Test operates two physical clinics serving metropolises and mobile units serving remote regions. Eligible women may self-refer to any provider for screening mammography.

PARTICIPANTS

Women aged 50 to 69 years who had at least one screening mammogram between July 2006 and June 2010 in Alberta were included. Women with missing health region information or prior breast cancer diagnosis were excluded.

RESULTS

A total of 389 788 screening mammograms were analysed, of which 12.7% were performed by Screen Test. Compared with Screen Test during 2006 to 2008, community radiology clinics had a lower cancer detection rate (3.6 vs 4.6 per 1000 screens, risk ratio (RR): 0.81, 95% CI: 0.67 to 0.98) and a much higher false positive rate (9.4% vs 3.4%, RR: 2.72, 95% CI: 2.55 to 2.90). Most other performance indicators were also better in Screen Test overall and across all health regions. These performance indicators were similar during 2008 to 2010, showing no improvement with time.

CONCLUSIONS

Screen Test has a quality assurance process in place and performed significantly better. This provides empirical evidence of the effectiveness of a quality assurance process and may explain some of the large differences in breast cancer screening indicators between provinces and countries with formal programmes and those without.

Estimation of the benefit and harms of including clinical breast examination in an organized breast screening program

BACKGROUND

There is controversy about the value of clinical breast examination (CBE) in addition to mammography for breast screening. The study investigates the associations between risk factors such as mammographic density, hormone therapy use and family history and the effectiveness of screening mammography with or without CBE.

METHODS

The cohort consists of women 50-69 years old screened at the Ontario Breast Screening Program. The associations of the risk factors were investigated using a joint logistic regression model that accommodates the partially unobserved disease status, clustered data structures, individual risk factors, and the dependence between true and false detection.

RESULTS

Having high mammographic density, a first degree relative with breast cancer and using hormone therapy generally increased a woman's probability of being referred correctly. For low risk group (defined as without dense breasts, family history, and not currently using hormone therapy), the average loss of specificity ranged from 3.6% to 5.7% and the gain of sensitivity was between 10.6% and 21.2% with the addition of CBE.

CONCLUSIONS

The addition of CBE to mammography would increase the overall sensitivity and decrease the specificity. CBE can be targeted to those women in which it has the highest net benefit.

Screening for a new primary cancer in patients with existing metastatic cancer: a retrospective cohort study

BACKGROUND

Cancer screening aims to detect malignant disease early in its natural history when interventions might improve patient outcomes. Such benefits are unclear when screening occurs for patients with an existing high risk of death. Our aim was to study the extent of routine cancer screening for a new primary cancer in patients with existing metastatic cancer.

METHODS

We used administrative databases from Ontario to identify a retrospective cohort of adults of eligible screening age (≥ 50 yr) who had a diagnosis of stage IV (metastatic) colorectal, lung, breast or prostate cancer between 2007 and 2012. We calculated the cumulative incidence of cancer screening over time for colorectal and breast cancer.

RESULTS

Among the 20 992 patients with metastatic lung, breast or prostate cancer, 2.9%, 6.3% and 13.3% of patients, respectively, underwent testing for colorectal cancer within 1 year of cancer diagnosis. Within 3 years of diagnosis, rates reached 4.1%, 12.3% and 27.5%, respectively (8.5% of all patients). Incidence of colorectal cancer testing was higher among patients who received their diagnoses more recently compared with patients with diagnoses from earlier time periods (p = 0.0143). Among the 10 034 women with metastatic lung or colorectal cancer, 8.7% and 8.0% of patients, respectively, underwent breast cancer screening within 1 year of cancer diagnosis. Within 3 years of diagnosis, screening rates reached 10.2% and 13.1%, respectively.

INTERPRETATION

Our findings indicate excessive rates of cancer screening among patients with metastatic cancer who are unlikely to benefit. Further studies are warranted to identify predictors for screening, resource implications, potential and real harms borne by patients, and the impact of a recent Choosing Wisely statement recommending against the practice.

Validity of Administrative Databases in Comparison to Medical Charts for Breast Cancer Treatment Data

Objective

Medical chart abstraction is the gold standard for collecting breast cancer treatment data for monitoring and research. A less costly alternative is the use of administrative databases. This study will evaluate administrative data in comparison to medical charts for breast cancer treatment information.

Study Design and Setting

A retrospective cohort design identified 2,401 women in the Ontario Breast Screening Program diagnosed with invasive breast cancer from 2006 to 2009. Treatment data were obtained from the Activity Level Reporting and Canadian Institute of Health Information databases. Medical charts were abstracted at cancer centres. Sensitivity, specificity, positive and negative predictive value, and kappa were calculated for receipt and type of treatment, and agreement was assessed for dates. Logistic regression evaluated factors influencing agreement.

Results

Sensitivity and specificity for receipt of radiotherapy (92.0%, 99.3%), chemotherapy (77.7%, 99.2%), and surgery (95.8%, 100%) were high but decreased slightly for specific radiotherapy anatomic locations, chemotherapy protocols, and surgeries. Agreement increased by radiotherapy year (trend test, p < 0.0001). Stage II/III compared to stage I cancer decreased odds of agreement for chemotherapy (OR = 0.66, 95% CI: 0.48–0.91) and increased agreement for partial mastectomy (OR = 3.36, 95% CI: 2.27–4.99). Exact agreement in treatment dates varied from 83.0% to 96.5%.

Conclusion

Administrative data can be accurately utilized for future breast cancer treatment studies.

The impact of false positive breast cancer screening mammograms on screening retention: A retrospective population cohort study in Alberta, Canada

OBJECTIVES

The impact of false positives on breast cancer screening retention is inconsistent across international studies. We investigate factors associated with screening retention, including false positive screening results, invasiveness of diagnostic procedures, and geographic variation in Alberta, Canada.

METHODS

A total of 213 867 women aged 50-67 years who had an index screen mammogram between July 2006 and June 2008 were evaluated at 30 months post index screen to determine the screening retention rate. The association of screening retention with invasiveness of the diagnostic procedure, time to diagnostic resolution, and region of residence were investigated using multivariable log binomial regression, adjusting for women's age.

RESULTS

Women with false positive screening results were less likely to return for their next recommended screening than those with a true negative result (62.0% vs. 68.7%). Compared to women with normal screening results, the adjusted risk ratios of fail-to-rescreen for women with imaging-only follow-up, needle sampling, and open biopsy were 1.08 (95% CI: 1.05-1.12), 1.72 (95% CI: 1.44-2.07) and 2.29 (95% CI: 2.09-2.50) respectively. Screening retention rates were slightly higher for rural residents than urban residents. Time to diagnostic resolution was not associated with screening retention. Screening retention peaked at one year from the index date of the previous screening.

CONCLUSION

Higher awareness of the strong negative impact that biopsies in the case of a false positive screening have on screening retention is needed. Such awareness can inform intervention strategies to mitigate the impact and improve screening retention rate.

Insurance-Based Differences in Time to Diagnostic Follow-up after Positive Screening Mammography

BACKGROUND

Insurance may lengthen or inhibit time to follow-up after positive screening mammography. We assessed the association between insurance status and time to initial diagnostic follow-up after a positive screening mammogram.

METHODS

Using 1995-2010 data from a North Carolina population-based registry of breast imaging and cancer outcomes, we identified women with a positive screening mammogram. We compared receipt of follow-up within 60 days of screening using logistic regression and evaluated time to follow-up initiation using Cox proportional hazards regression.

RESULTS

Among 43,026 women included in the study, 73% were <65 years and 27% were 65+ years. Median time until initial diagnostic follow-up was similar by age group and insurance status. In the adjusted model for women <65, uninsured women experienced a longer time to initiation of diagnostic follow-up [HR, 0.47; 95% confidence interval (CI), 0.25-0.89] versus women with private insurance. There were increased odds of these uninsured women not meeting the Centers for Disease Control and Prevention guideline for follow-up within 60 days (OR, 1.59; 95% CI, 1.31-1.94). Among women ages 65+, women with private insurance experienced a faster time to follow-up (adjusted HR, 2.09; 95% CI, 1.27-3.44) than women with Medicare and private insurance. Approximately 10% of women had no follow-up by 365 days.

CONCLUSIONS

We found differences in time to initial diagnostic follow-up after a positive screening mammogram by insurance status and age group. Uninsured women younger than 65 years at a positive screening event had delayed follow-up.

IMPACT

Replication of these findings and examination of their clinical significance warrant additional investigation. Cancer Epidemiol Biomarkers Prev; 25(11); 1474-82. ©2016 AACR.

Mammographic features associated with interval breast cancers in screening programs

INTRODUCTION

Percent mammographic density (PMD) is associated with an increased risk of interval breast cancer in screening programs, as are younger age, pre-menopausal status, lower body mass index and hormone therapy. These factors are also associated with variations in PMD. We have examined whether these variables influence the relative frequency of interval and screen-detected breast cancer, independently or through their associations with PMD. We also examined the association of tumor size with PMD and dense and non-dense areas in screen-detected and interval breast cancers.

METHODS

We used data from three case-control studies nested in screened populations. Interval breast cancer was defined as invasive breast cancer detected within 12 months of a negative mammogram. We used a computer-assisted method of measuring the dense and total areas of breast tissue in the first (baseline) mammogram taken at entry to screening programs and calculated the non-dense area and PMD. We compared these mammographic features, and other risk factors at baseline, in women with screen-detected (n = 718) and interval breast cancer (n = 125).

RESULTS

In multi-variable analysis, the baseline characteristics of younger age, greater dense area and smaller non-dense mammographic area were significantly associated with interval breast cancer compared to screen-detected breast cancer. Compared to screen-detected breast cancers, interval cancers had a larger maximum tumor diameter within each mammographic measure.

CONCLUSIONS

Age and the dense and non-dense areas in the baseline mammogram were independently associated with interval breast cancers in screening programs. These results suggest that decreased detection of cancers caused by the area of dense tissue, and more rapid growth associated with a smaller non-dense area, may both contribute to risk of interval breast cancer. Tailoring screening to individual mammographic characteristics at baseline may reduce the number of interval cancers.

Digital compared to screen-film mammography: breast cancer prognostic features in an organized screening program

Our previous study found cancer detection rates were equivalent for direct radiography compared to screen-film mammography, while rates for computed radiography were significantly lower. This study compares prognostic features of invasive breast cancers by type of mammography. Approved by the University of Toronto Research Ethics Board, this study identified invasive breast cancers diagnosed among concurrent cohorts of women aged 50-74 screened by direct radiography, computed radiography, or screen-film mammography from January 1, 2008 to December 31, 2009. During the study period, 816,232 mammograms were performed on 668,418 women, and 3,323 invasive breast cancers were diagnosed. Of 2,642 eligible women contacted, 2,041 participated (77.3 %). The final sample size for analysis included 1,405 screen-detected and 418 interval cancers (diagnosed within 24 months of a negative screening mammogram). Polytomous logistic regression was performed to evaluate the association between tumour characteristics and type of mammography, and between tumour characteristics and detection method. Odds ratios (OR) and 95 % confidence intervals (CI) were recorded. Cancers detected by computed radiography compared to screen-film mammography were significantly more likely to be lymph node positive (OR 1.94, 95 %CI 1.01-3.73) and have higher stage (II:I, OR 2.14, 95 %CI 1.11-4.13 and III/IV:I, OR 2.97, 95 %CI 1.02-8.59). Compared to screen-film mammography, significantly more cancers detected by direct radiography (OR 1.64, 95 %CI 1.12-2.38) were lymph node positive. Interval cancers had worse prognostic features compared to screen-detected cancers, irrespective of mammography type. Screening with computed radiography may lead to the detection of cancers with a less favourable stage distribution compared to screen-film mammography that may reflect a delayed diagnosis. Screening programs should re-evaluate their use of computed radiography for breast screening.

Effectiveness of Screening With Annual Magnetic Resonance Imaging and Mammography: Results of the Initial Screen From the Ontario High Risk Breast Screening Program

Purpose

The Ontario Breast Screening Program expanded in July 2011 to screen women age 30 to 69 years at high risk for breast cancer with annual magnetic resonance imaging (MRI) and digital mammography. To the best of our knowledge, this is the first organized screening program for women at high risk for breast cancer.

Patients and Methods

Performance measures after assessment were compared with screening results for 2,207 women with initial screening examinations. The following criteria were used to determine eligibility: known mutation in BRCA1, BRCA2, or other gene predisposing to a markedly increased risk of breast cancer, untested first-degree relative of a gene mutation carrier, family history consistent with hereditary breast cancer syndrome and estimated personal lifetime breast cancer risk ≥ 25%, or radiation therapy to the chest (before age 30 years and at least 8 years previously).

Results

The recall rate was significantly higher among women who had abnormal MRI alone (15.1%; 95% CI, 13.8% to 16.4%) compared with mammogram alone (6.4%; 95% CI, 5.5% to 7.3%). Of the 35 breast cancers detected (16.3 per 1,000; 95% CI, 11.2 to 22.2), none were detected by mammogram alone, 23 (65.7%) were detected by MRI alone (10.7 per 1,000; 95% CI, 6.7 to 15.8), and 25 (71%) were detected among women who were known gene mutation carriers (30.8 per 1,000, 95% CI, 19.4 to 43.7). The positive predictive value was highest for detection based on mammogram and MRI (12.4%; 95% CI, 7.3% to 19.3%).

Conclusion

Screening with annual MRI combined with mammography has the potential to be effectively implemented into an organized breast screening program for women at high risk for breast cancer. This could be considered an important management option for known BRCA gene mutation carriers.

Impact of socio-economic status on breast cancer screening in women with diabetes: a population-based study

AIMS

There is evidence to suggest that mammography rates are decreased in women with diabetes and in women of lower socio-economic status. Given the strong association between low socio-economic status and diabetes, we explored the extent to which differences in socio-economic status explain lower mammography rates in women with diabetes.

METHODS

A population-based retrospective cohort study in Ontario, Canada, of women aged 50 to 69 years with diabetes between 1999 and 2010 age matched 1:2 to women without diabetes. Main outcome measure is the likelihood of at least one screening mammogram in women with diabetes within a 36-month period, starting as of either 1 January 1999, their 50th birthday, or 2 years after diabetes diagnosis--whichever came last. Outcomes were compared with those in women without diabetes during the same period as their matched counterparts, adjusting for socio-economic status based on neighbourhood income and other demographic and clinical variables.

RESULTS

Of 504,288 women studied (188,759 with diabetes, 315,529 with no diabetes), 63.8% had a screening mammogram. Women with diabetes were significantly less likely to have a mammogram after adjustment for socio-economic status and other factors (odds ratio 0.79, 95% CI 0.78-0.80). Diabetes was associated with lower mammogram use even in women from the highest socio-economic status quintile (odds ratio 0.79, 95% CI 0.75-0.83).

CONCLUSIONS

The presence of diabetes was an independent barrier to breast cancer screening, which was not explained by differences in socio-economic status. Interventions that target patient, provider, and health system factors are needed to improve cancer screening in this population.

Does perceived risk predict breast cancer screening use? Findings from a prospective cohort study of female relatives from the Ontario site of the breast cancer family registry

While the relationship between perceived risk and breast cancer screening use has been studied extensively, most studies are cross-sectional. We prospectively examined this relationship among 913 women, aged 25-72 with varying levels of familial breast cancer risk from the Ontario site of the Breast Cancer Family Registry. Associations between perceived lifetime breast cancer risk and subsequent use of mammography, clinical breast examination (CBE) and genetic testing were assessed using logistic regression. Overall, perceived risk did not predict subsequent use of mammography, CBE or genetic testing. Among women at moderate/high familial risk, those reporting a perceived risk greater than 50% were significantly less likely to have a CBE (odds ratio (OR) = 0.52, 95% confidence interval (CI): 0.30-0.91, p = 0.04), and non-significantly less likely to have a mammogram (OR = 0.70, 95% CI: 0.40-1.20, p = 0.70) or genetic test (OR = 0.61, 95% CI: 0.34-1.10, p = 0.09) compared to women reporting a perceived risk of 50%. In contrast, among women at low familial risk, those reporting a perceived risk greater than 50% were non-significantly more likely to have a mammogram (OR = 1.13, 95% CI: 0.59-2.16, p = 0.78), CBE (OR = 1.11, 95% CI: 0.63-1.95, p = 0.74) or genetic test (OR = 1.29, 95% CI: 0.50-3.33, p = 0.35) compared to women reporting a perceived risk of 50%. Perceived risk did not significantly predict screening use overall, however this relationship may be moderated by level of familial risk. Results may inform risk education and management strategies for women with varying levels of familial breast cancer risk.

Clinical and prognostic factors associated with diagnostic wait times by breast cancer detection method

Introduction

Although prognostic differences between screen-detected, interval and symptomatic breast cancers are known, factors associated with wait times to diagnosis among these three groups have not been studied.

Methods

Of the 16,373 invasive breast cancers diagnosed between January 1, 1995 and December 31, 2003 in a cohort of Ontario women aged 50 to 69, a random sample (N = 2,615) were selected for chart abstraction. Eligible women were classified according to detection method; screen-detected (n = 1181), interval (n = 319) or symptomatic (n = 406). Diagnostic wait time was calculated from the initial imaging or biopsy to breast cancer diagnosis. Logistic regression analysis examined associations between diagnostic wait times dichotomized as greater or less than the median and demographic, clinical and prognostic factors separately for each detection cohort.

Results

Women who underwent an open biopsy had significantly longer than median wait times to diagnosis, compared to women who underwent a fine needle aspiration or core biopsy; (screen-detected OR = 2.76, 95% CI = 2.14-3.56; interval OR = 2.56, 95% CI = 1.50-4.35; symptomatic OR = 5.56, 95% CI = 3.33-9.30). Additionally, screen-detected breast cancers diagnosed with stage II and symptomatic cancers diagnosed at stage III or IV had significantly shorter diagnostic wait times compared to those diagnosed at stage 1 (OR = 0.66 95% CI = 0.50-0.87 and OR = 0.46, 95% CI = 0.25-0.85 respectively).

Conclusions

Our study is consistent with expedited diagnostic work-up for breast cancers with more advanced prognostic features. Furthermore, women who had an open surgical biopsy had a greater than the median diagnostic wait time, irrespective of detection method.

Using organizational network analysis to plan cancer screening programs for vulnerable populations

OBJECTIVES

We examined relationships among organizations in a cancer screening network to inform the development of interventions to improve cancer screening for South Asians living in the Peel region of Ontario.

METHODS

From April to July 2012, we surveyed decision-makers, program managers, and program staff in 22 organizations in the South Asian cancer screening network in the Peel region. We used a network analytic approach to evaluate density (range = 0%-100%, number of ties among organizations in the network expressed as a percentage of all possible ties), centralization (range = 0-1, the extent of variability in centrality), and node characteristics for the communication, collaboration, and referral networks.

RESULTS

Density was similar across communication (15%), collaboration (17%), and referral (19%) networks. Centralization was greater in the collaboration network (0.30) than the communication network (0.24), and degree centralization was greater in the inbound (0.42) than the outbound (0.37) referral network. Diverse organizations were central to the networks.

CONCLUSIONS

Certain organizations were unexpectedly important to the South Asian cancer screening network. Program planning was informed by identifying opportunities to strengthen linkages between key organizations and to leverage existing ties.

Impact of familial risk and mammography screening on prognostic indicators of breast disease among women from the Ontario site of the Breast Cancer Family Registry

Although several studies have found screen-detected cancers in women with familial breast cancer risk have favorable prognostic features compared with symptomatic cancers, the impact of level of familial risk is unknown. A cohort of 899 first-degree female relatives of cases of breast cancer from the Ontario site of the Breast Cancer Family Registry was followed for 2 years. Logistic regression analyses compared diagnoses of breast cancer or benign breast disease (BBD) between women at high (n = 258, 28.7 %) versus low/moderate (n = 641, 71.3 %) familial risk. Similar analyses compared prognostic features of invasive cancers and BBD by level of familial risk and mammography screening status. Among 899 women, 44 (4.9 %) were diagnosed with invasive breast cancer and/or ductal carcinoma in situ, and 56 (6.2 %) with BBD. Women with high familial risk were significantly more likely to be diagnosed with breast cancer [odds ratio (OR) = 2.84, 95 % confidence interval (CI) 1.50-5.38] than low/moderate risk women, particularly if diagnosed at age ≥50 (OR = 2.99, 95 % CI 1.37-6.56) or screened with mammography (OR = 3.33, 95 % CI 1.54-7.18). High risk women were more likely to be diagnosed with BBD (OR = 1.94, 95 % CI 1.03-3.66). Level of familial risk was not associated with prognostic features. Cancers among unscreened women were larger (OR = 9.72, 95 % CI 1.01-93.61) and diagnosed at stage II or above (OR = 7.80, 95 % CI 1.18-51.50) compared with screen-detected cancers. Screening mammography may be effective for women with a first-degree family history of breast cancer, irrespective of level of familial risk.

Factors associated with wait times across the breast cancer treatment pathway in Ontario

BACKGROUND

Longer times from diagnosis to breast cancer treatment are associated with poorer prognosis. This study examined factors associated with wait times by phase in the breast cancer treatment pathway.

METHODS

There were 1760 women eligible for the study, aged 50-69 diagnosed in Ontario with invasive breast cancer from 1995-2003. Multivariate logistic regression examined factors associated with greater than median wait times for each phase of the treatment pathway; from diagnosis to definitive surgery; from final surgery to radiotherapy without chemotherapy and from final surgery to chemotherapy.

RESULTS

The median wait times were 17 days (Inter Quartile Range (IQR) = 0-31) from diagnosis to definitive surgery, 44 days (IQR = 34-56) from final surgery to postoperative chemotherapy and 75 days (IQR = 57-97) from final surgery to postoperative radiotherapy. Diagnosis during 2000-2003 compared to 1995-1999 was associated with significantly longer wait times for each phase of the treatment pathway. Higher income quintile was associated with longer wait time from diagnosis to surgery (OR = 1.47, 95% CI = 1.05-2.06) and shorter wait times from final surgery to radiotherapy (OR = 0.60, 95% CI = 0.37-0.96). Greater stage at diagnosis was associated with shorter wait times from diagnosis to definitive surgery (stage III vs I: OR = 0.49, 95% CI = 0.34-0.71).

CONCLUSIONS

While diagnosis during the latter part of the study period was associated with significantly longer wait times for all phases of the treatment pathway, there were variations in the associations of stage and income quintile with wait times by treatment phase. Continued assessment of factors associated with wait times across the breast cancer treatment pathway is important, as they indicate areas to be targeted for quality improvement with the ultimate goal of improving prognosis.

Accuracy of Self-Reported Screening Mammography Use: Examining Recall among Female Relatives from the Ontario Site of the Breast Cancer Family Registry

Evidence of the accuracy of self-reported mammography use among women with familial breast cancer risk is limited. This study examined the accuracy of self-reported screening mammography dates in a cohort of 1,114 female relatives of breast cancer cases, aged 26 to 73 from the Ontario site of the Breast Cancer Family Registry. Self-reported dates were compared to dates abstracted from imaging reports. Associations between inaccurate recall and subject characteristics were assessed using multinomial regression. Almost all women (95.2% at baseline, 98.5% at year 1, 99.8% at year 2) accurately reported their mammogram use within the previous 12 months. Women at low familial risk (OR = 1.77, 95% CI: 1.00–3.13), who reported 1 or fewer annual visits to a health professional (OR = 1.97, 95% CI: 1.15, 3.39), exhibited a lower perceived breast cancer risk (OR = 1.90, 95% CI: 1.15, 3.15), and reported a mammogram date more than 12 months previous (OR = 5.22, 95% CI: 3.10, 8.80), were significantly more likely to inaccurately recall their mammogram date. Women with varying levels of familial risk are accurate reporters of their mammogram use. These results present the first evidence of self-reported mammography recall accuracy among women with varying levels of familial risk.

Planning cancer control in Latin America and the Caribbean

Non-communicable diseases, including cancer, are overtaking infectious disease as the leading health-care threat in middle-income and low-income countries. Latin American and Caribbean countries are struggling to respond to increasing morbidity and death from advanced disease. Health ministries and health-care systems in these countries face many challenges caring for patients with advanced cancer: inadequate funding; inequitable distribution of resources and services; inadequate numbers, training, and distribution of health-care personnel and equipment; lack of adequate care for many populations based on socioeconomic, geographic, ethnic, and other factors; and current systems geared toward the needs of wealthy, urban minorities at a cost to the entire population. This burgeoning cancer problem threatens to cause widespread suffering and economic peril to the countries of Latin America. Prompt and deliberate actions must be taken to avoid this scenario. Increasing efforts towards prevention of cancer and avoidance of advanced, stage IV disease will reduce suffering and mortality and will make overall cancer care more affordable. We hope the findings of our Commission and our recommendations will inspire Latin American stakeholders to redouble their efforts to address this increasing cancer burden and to prevent it from worsening and threatening their societies.

Using concept mapping in the knowledge-to-action process to compare stakeholder opinions on barriers to use of cancer screening among South Asians

BACKGROUND

Using the knowledge-to-action (KTA) process, this study examined barriers to use of evidence-based interventions to improve early detection of cancer among South Asians from the perspective of multiple stakeholders.

METHODS

In 2011, we used concept mapping with South Asian residents, and representatives from health service and community service organizations in the region of Peel Ontario. As part of concept mapping procedures, brainstorming sessions were conducted with stakeholders (n = 53) to identify barriers to cancer screening among South Asians. Participants (n = 46) sorted barriers into groups, and rated barriers from lowest (1) to highest (6) in terms of importance for use of mammograms, Pap tests and fecal occult blood tests, and how feasible it would be to address them. Multi-dimensional scaling, cluster analysis, and descriptive statistics were used to analyze the data.

RESULTS

A total of 45 unique barriers to use of mammograms, Pap tests, and fecal occult blood tests among South Asians were classified into seven clusters using concept mapping procedures: patient's beliefs, fears, lack of social support; health system; limited knowledge among residents; limited knowledge among physicians; health education programs; ethno-cultural discordance with the health system; and cost. Overall, the top three ranked clusters of barriers were 'limited knowledge among residents,' 'ethno-cultural discordance,' and 'health education programs' across surveys. Only residents ranked 'cost' second in importance for fecal occult blood testing, and stakeholders from health service organizations ranked 'limited knowledge among physicians' third for the feasibility survey. Stakeholders from health services organizations ranked 'limited knowledge among physicians' fourth for all other surveys, but this cluster consistently ranked lowest among residents.

CONCLUSION

The limited reach of cancer control programs to racial and ethnic minority groups is a critical implementation issue that requires attention. Opinions of community service and health service organizations on why this deficit in implementation occurs are fundamental to understanding the solutions because these are the settings in which evidence-based interventions are implemented. Using concept mapping within a KTA process can facilitate the engagement of multiple stakeholders in the utilization of study results and in identifying next steps for action.

Improving work-up of the abnormal mammogram through organized assessment: results from the ontario breast screening program

PURPOSE

Women with an abnormal screening mammogram should ideally undergo an organized assessment to attain a timely diagnosis. This study evaluated outcomes of women undergoing work-up after abnormal mammogram through a formal breast assessment affiliate (BAA) program with explicit care pathways compared with usual care (UC) using developed quality indicators for screening mammography programs.

METHODS

Between January 1 and December 31, 2007, a total of 320,635 women underwent a screening mammogram through the Ontario Breast Screening Program (OBSP), of whom 25,543 had an abnormal result requiring further assessment. Established indicators assessing timeliness, appropriateness of follow-up, and biopsy rates were compared between women who were assessed through either a BAA or UC using χ(2) analysis.

RESULTS

Work-up of the abnormal mammogram for patients screened through a BAA resulted in a greater proportion of women attaining a definitive diagnosis within the recommended time interval when a histologic diagnosis was required. In addition, use of other quality measures including specimen radiography for both core biopsies and surgical specimens and preoperative core needle biopsy was greater in BAA facilities.

CONCLUSION

These findings support future efforts to increase the number of BAAs within the OBSP, because the pathways and reporting methods associated with them result in improvements in our ability to provide timely and appropriate care for women requiring work-up of an abnormal mammogram.

Satisfaction with initial screen and compliance with biennial breast screening at centers with and without nurses

BACKGROUND

A woman's experience during her initial breast screen can influence her participation in subsequent screening.

OBJECTIVE

The purpose of this study was to determine the association between a woman's satisfaction with her initial screening experience and compliance to biennial screening at centers with and without nurses.

METHODS

A stratified random sample of compliers and noncompliers to biennial screening was selected from a cohort of 16 858 eligible women aged 50 to 65 years attending centers with and without nurses for their initial screen at the Ontario Breast Screening Program in 2002. Of these eligible women, 3387 were sent questionnaires, 2640 (77.9%) were contacted, and 1901 (72.0%) were interviewed. The association between satisfaction with initial screen and compliance was estimated separately for centers with and without nurses using logistic regression.

RESULTS

Women attending centers with nurses were significantly less likely to comply with their next screen after their clinical breast examination if they were not completely satisfied with the service they received (odds ratio, 0.21; 95% confidence interval, 0.08-0.57) or agreed that the clinical breast examination caused discomfort to their breasts (odds ratio, 0.65; 95% confidence interval, 0.45-0.94). In addition, women attending centers with or without nurses were significantly less likely to comply if they did not understand why they needed to return for screening.

CONCLUSIONS

: Nurses at screening centers have an opportunity to significantly impact a woman's compliance to biennial breast screening by providing a positive initial screening experience.

IMPLICATIONS FOR PRACTICE

Emphasis should be placed on improving a woman's overall satisfaction with her initial screening experience.

Tumor characteristics associated with mammographic detection of breast cancer in the Ontario breast screening program

BACKGROUND

Few studies have compared the prognostic value of tumor characteristics by type of breast cancer diagnosed in the interval between mammographic screenings with screen-detected breast cancers.

METHODS

We conducted a case-case study within the cohort of women (n = 431 480) in the Ontario Breast Screening Program who were aged 50 years and older and were screened between January 1, 1994, and December 31, 2002. Interval cancers, defined as breast cancers diagnosed within 24 months after a negative screening mammogram, were designated as true interval cancers (n = 288) or missed interval cancers (n = 87) if they were not identified at the time of screening but were identified in retrospect. Screen-detected breast cancers (n = 450) were selected to match interval cancers. Tumors were evaluated for stage, grade, mitotic index, histology, and expression of hormone receptors and odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by conditional logistic regression.

RESULTS

Both true and missed interval cancers were of higher stage and grade than matched screen-detected breast cancers. However, true interval cancers had a higher mitotic index (OR = 3.13, 95% CI = 1.81 to 5.42), a higher percentage of nonductal histology (OR = 1.94, 95% CI = 1.05 to 3.59), and were more likely to be both estrogen receptor-negative (OR = 2.09, 95% CI = 1.32 to 3.30) and progesterone receptor-negative (OR = 2.49, 95% CI = 1.68 to 3.70) compared with matched screen-detected tumors.

CONCLUSIONS

In this study, interval cancers were of higher stage and grade compared with screen-detected cancers. True interval cancers were more likely to have additional adverse prognostic features of estrogen and progesterone receptor negativity and nonductal morphology. The findings suggest a need for more sensitive screening modalities to detect true interval breast cancers and different approaches for early detection of fast-growing tumors.

Optimization of clinical breast examination

BACKGROUND

Breast examination is necessary for evaluation of the 8% to 17% of cancers missed by mammograms, but it is being done less often and less effectively. To improve the use of breast examination, we tested whether a technique to focus attention could improve the call rate (the percent of examinations leading to further evaluation), a measure of quality, without retraining in examination technique.

METHODS

Clinicians were randomized to complete 1 of 2 dedicated, de-identified forms after routine breast examination: a long form intended to focus attention by requesting general breast descriptors along with clinical information and breast examination findings (10 clinicians recorded 964 examinations) or a short form recording only clinical information and examination findings (11 clinicians recorded 558 examinations). There was no technique retraining. Study call rates were compared with historical controls (298 breast examinations by 16 clinicians).

RESULTS

The call rates by the study groups of clinicians were similar, but the call rate using either form (8.3%) was significantly higher than the call rate in the preceding year when no dedicated form was used (4.7%; P=.031), suggesting a Hawthorne effect in which altering conditions of data collection (using the dedicated forms) functioned as an independent variable. Surveillance, Epidemiology, and End Results data predicted 3.4 cancers in all 1822 patients; 4 cancers were found.

CONCLUSION

Breast examination call rate doubled when attention was focused on examination results using a dedicated form, and we found the anticipated cancers. Breast examination quality can be improved by focusing clinician attention without retraining in technique.

Trends in laboratory testing for diabetes in Ontario, Canada 1995-2005: a population-based study

BACKGROUND

There are concerns that testing for type 2 diabetes is low and many people with diabetes are not diagnosed. We sought to describe the rates of diabetes-related lab testing in Ontario from 1995-2005, among adults without diabetes, and to explore the extent to which the Canadian clinical practice guidelines for screening are being followed.

METHODS

Descriptive counts of outpatient diabetes laboratory tests performed within Ontario's publicly funded, provincial health insurance program were recorded. The study population was Ontario residents, 20 years and older from 1995 to 2005 (9.3 million people in 2005). The Ontario Diabetes Database, a cumulative registry derived from administrative health records, was used to exclude people who had physician-diagnosed diabetes (n = 839,127 in 2005) from the primary analyses. Diabetes tests included serum blood glucose (SBG), hemoglobin A1c (HbA1c), and oral glucose tolerance tests (OGTT).

RESULTS

In 2005, 37% of Ontario adults without pre-existing diabetes were tested with an SBG test, a 28% increase from 1995. The age-adjusted proportion of adults without diabetes undergoing a HbA1c test increased from 1.7% in 1995 to 6.0% in 2005. In 2005, a similar number of HbA1c tests were performed for individuals with diabetes (483,746) and without diabetes (496,616) despite large differences in the two groups' denominators. Less than 1% of Ontarians underwent OGTT testing in any year between 1995-2005. Nearly two-thirds of adults age 40 years and over had an SBG test over a 3-year period (April 1, 2002-March 31, 2005), in accordance with the Canadian Diabetes Association recommendations.

CONCLUSION

Diabetes testing is common and has increased over the last ten years. Despite its absence in Canada's diabetes screening recommendations, HbA1c testing among individuals without diabetes is increasing rapidly, and OGTT, which is recommended, is rarely performed.

Predisposing factors associated with compliance to biennial breast screening among centers with and without nurses

BACKGROUND

Previous research suggests that predisposing factors such as previous screening experience, participation in preventive health behaviors, and knowledge/beliefs about breast cancer and screening influence a woman's decision to make a timely return for a second screen.

METHODS

A stratified random sample of compliers and noncompliers to biennial screening were selected from a cohort of 51,242 women ages 50 to 65 years who had their initial screen at the Ontario Breast Screening Program. In total, 1,901 women were telephone-interviewed. The associations between predisposing factors and compliance were estimated separately for centers with and without nurses using logistic regression analyses adjusted for demographics and smoking status.

RESULTS

Women screened at nurse centers were less likely to comply if they thought women should stop having mammograms before age 70 years [odds ratio (OR), 0.39; 95% confidence interval (95% CI), 0.19-0.79], did not consider mammograms very likely to find cancer (OR, 0.73; 95% CI, 0.56-0.95), felt their likeliness of getting breast cancer was below average (OR, 0.69; 95% CI, 0.54-0.89), or believed a high-fat diet was not an important risk factor for breast cancer (OR, 0.59; 95% CI, 0.36-0.97). Women attending nurse centers were significantly more likely to comply if they sometimes had thoughts or worries about developing breast cancer (OR, 1.40; 95% CI, 1.10-1.80).

CONCLUSIONS

Nurses at screening centers may reinforce a woman's knowledge or beliefs about breast cancer or screening and as a result increase their compliance to biennial breast screening.

Influence of physician and patient characteristics on adherence to breast cancer screening recommendations

Identifying physician and patient characteristics is important in implementing effective, targeted strategies to improve breast cancer detection rates through increased screening recommendations and uptake. The purpose of this study was to determine whether Ontario physicians recommend breast screening using mammography every 2 years for women aged 50-69 as encouraged by the Ontario Breast Screening Program. This study also aimed to identify physician and patient characteristics that may influence adherence to these recommendations. The study design was a cross-sectional study. Using the Canadian Medical Directory-Ontario database, 3063 questionnaires were mailed to all active general and family practitioners. A response rate of 38% (N = 939) was achieved. Adherence to screening was defined as recommending screening to women aged 50-69 only, every 2 years as outlined by the Ontario Breast Screening Program. Bivariate analyses and unconditional logistic regression were used to assess physician adherence to screening guidelines. Only 38.9% of physicians followed recommended breast screening guidelines. After adjusting for physician sex and age, predictors of screening adherence include physicians working in academic or research centers (odds ratio 8.3, 95% confidence interval 1.7-39.7) and those reporting that over 31% of their patients to be of low-income (odds ratio 1.6, 95% confidence interval 1.1-2.4). Compared with physicians working in a rural/town setting (<10 000 people), those located in a large city (>100 000 people) were less likely to adhere to screening guidelines (odds ratio 0.5, 95% confidence interval 0.3-0.7). A low proportion of Ontario physicians adhere to recommended breast screening guidelines. Future research into effective strategies to increase adherence should take into account practice location, setting and patient characteristics.

Influence of Patterns of Hormone Replacement Therapy Use and Mammographic Density on Breast Cancer Detection

BACKGROUND

There is evidence that factors such as current hormone replacement therapy (HRT) use and mammographic density may each lower the sensitivity of mammography and are associated with a greater risk of developing an interval cancer. This study explores this relationship further by examining the influence of patterns of HRT use and the percentage of mammographic density on the detection of breast cancer by classification of interval cancer.

METHODS

This study uses a case-case design nested within a cohort of women screened by the Ontario Breast Screening Program between 1994 and 2002. Interval cancers, both those missed at screening but seen on retrospective review (n = 87) or true intervals without visible tumor signs at screening (n = 288) were matched to 450 screen-detected cancers. The association between the percentage of mammographic density, measured by radiologists and a computer-assisted method, and HRT use, ascertained from a mailed questionnaire, and the risk of being diagnosed with an interval cancer was estimated using conditional logistic regression.

RESULTS

A monotonic gradient of increasing risk for interval cancers was found for each 25% increase in mammographic density [odds ratio (OR), 1.77; 95% confidence intervals (95% CI), 1.07-2.95 for missed intervals and OR, 2.16; 95% CI, 1.59-2.94 for true intervals]. After adjusting for mammographic density, a significantly increased risk for true-interval cancers remained for women taking estrogen alone (OR, 1.75; 95% CI, 1.11-2.83) as well as for missed- (OR, 2.84; 95% CI, 1.32-6.13) and true-interval cancers (OR, 1.79; 95% CI, 1.10-2.90) for women taking combined HRT.

CONCLUSIONS

Information on mammographic density and HRT use should routinely be collected at the time of screening. Women at risk should be made aware of the lower sensitivity of mammography and offered alternative procedures for screening.