Alberta Breast Cancer Research Articles

Real World Evidence Study to Assess Incidence, Treatment Patterns, Clinical Outcomes, and Health Care Resource Utilization in Early-Stage, High-Risk HER2-Negative Breast Cancer in Alberta, Canada

BackgroundData are needed to improve the current understanding of the epidemiology of patients with high-risk, HER2-negative, early breast cancer (eBC) (hormone receptor positive [HR+]/HER2-negative BC and triple-negative BC [TNBC]). Patients and MethodsThis retrospective longitudinal cohort study used real-world, population-level data that included all individuals newly diagnosed with high-risk, HER2-negative eBC in Alberta, Canada, between 2010 and 2019. Data on treatment, laboratory results and pathology findings were collected through electronic health records and administrative databases. ResultsThe annual cumulative incidence of high-risk, HER2-negative eBC ranged from 6% to 9% of all incident BC cases. Individuals with TNBC were more likely to be younger, had stage II disease, grade 3 histology and received systemic therapy at a community centre (P < .05) compared to individuals with HR+/HER2-negative eBC. Only 14% of individuals diagnosed in 2010-2017 underwent germline BRCA testing postdiagnosis. Neoadjuvant systemic therapy was given to 37% of individuals. Adjuvant systemic therapy use increased from 77% (2012-2015) to 84% (2019). The 5-year overall survival (OS) from initiation of adjuvant systemic therapy or date of surgery (for individuals who did not receive adjuvant systemic therapy) was 77% (95% CI: 75-79). OS was significantly worse among individuals who were older, had grade 3 histology, had stage III disease, or had nodal involvement (P < .05). OS among individuals with TNBC between 2016 and 2019 who initiated adjuvant capecitabine was markedly worse compared to the overall cohort (2-year OS: 70% vs. 89%). ConclusionOutcomes analyses in this high-risk, HER2-negative eBC population suggest a continued unmet clinical need.

Geographic variation in breast reconstruction surgery after mastectomy for females with breast cancer in Alberta, Canada.

Breast cancer is the most common cancer affecting females in Canada, and about half of females with breast cancer are treated with mastectomy. We sought to evaluate geographic variation in breast reconstruction surgery in Alberta, Canada. Using linked population-based administrative databases, we extracted data on all Alberta females aged 18 years and older who were diagnosed with breast cancer and treated with mastectomy during 2004-2017. Analyses included regression modelling of odds of reconstruction at 1 year and a spatial scan to identify geographic clusters of lower numbers of reconstruction. A total of 16 198 females diagnosed with breast cancer were treated with a mastectomy, and 1932 (11.9%) had reconstruction within 1 year postmastectomy. Those with reconstruction were more likely to be younger (adjusted odds ratio [OR] 16.7, 95% confidence interval [CI] 13.7-20.3; aged 21-44 yr v. ≥ 65 yr) and were less likely to be from lower-income neighbourhoods. They were more likely to have at least 1 comorbidity and were more likely to have advanced stages of cancer and to require chemotherapy (adjusted OR 0.55, 95% CI 0.47-0.65) or radiotherapy after mastectomy (adjusted OR 0.59, 95% CI 0.39-0.87) than females without reconstruction. We identified rural northern and southeastern clusters with frequencies of reconstruction that were 69.6% and 41.6% of what was expected, respectively. We found an overall postmastectomy rate of breast reconstruction of 11.9%, and we identified geographic variation. Predictors of reconstruction in Alberta were similar to those previously described in the literature, specifically with patients in rural communities having lower rates of reconstruction than their urban counterparts. These results suggest that further interventions are required to identify the specific barriers to reconstruction within rural communities and to create strategies to ensure equitable access to all residents.

Assessing Breast Cancer Screening and Outcomes Among First Nations Women in Alberta.

Breast cancer (BC) incidence rates for First Nations (FN) women in Canada have been steadily increasing and are often diagnosed at a later stage. Despite efforts to expand the reach of BC screening programs for FN populations in Alberta (AB), gaps in screening and outcomes exist. Existing population-based administrative databases including the AB BC Screening Program, the AB Cancer Registry, and an AB-specific FN registry data were linked to evaluate BC screening participation, detection, and timeliness of outcomes in this retrospective study. Tests of proportions and trends compared the findings between FN and non-FN women, aged 50-74years, beginning in 2008. Incorporation of FN principles of ownership, control, access, and possession (OCAP®) managed respectful sharing and utilization of FN data and findings. The average age-standardized participation (2013-8) and retention rates (2015-6) for FN women compared to non-FN women in AB were 23.8% (P < .0001) and 10.3% (P = .059) lower per year, respectively. FN women were diagnosed with an invasive cancer more often in Stage II (P-value = .02). Following 90% completion of diagnostic assessments, it took 2-4weeks longer for FN women to receive their first diagnosis as well as definitive diagnoses than non-FN women. Collectively, these findings suggest that access to and provision of screening services for FN women may not be equitable and may contribute to higher BC incidence and mortality rates. Collaborations between FN groups and screening programs are needed to eliminate these inequities to prevent more cancers in FN women.

Real-world impact of TAILORx on chemotherapy use and SOFT/TEXT on ovarian function suppression uptake in a population based-cohort of women 40 years and under with HR-positive, HER2-negative, axillary lymph node negative breast cancer.

534 Background: Gene expression profiling (GEP) testing is prognostic for distant recurrence risk in women with hormone receptor positive (HR+), human epidermal growth factor receptor-2 negative (HER2-), axillary lymph node negative (LN-) breast cancer (BC). The TAILORx trial generated prospective evidence demonstrating the 21-gene recurrence score (RS) is also predictive of chemotherapy (CT) benefit. The literature suggests that GEP testing reduces adjuvant CT prescription and is cost-effective. In the same era, the SOFT/TEXT trials demonstrated disease-free survival benefit for the addition of ovarian function suppression (OFS) to endocrine therapy in premenopausal women. Real-world uptake and impact of these advances in the management of HR+, HER2-, LN- BC in young women may be limited due to complex reasons. This retrospective study evaluated GEP and CT use post TAILORx and OFS use post SOFT/TEXT in women 40 years old or younger diagnosed with HR+, HER2-, LN BC from 2011 to 2020 in Alberta, Canada. Methods: Clinical variables were retrieved from the Alberta Health Services Cancer Care Breast Data Mart and through review of the electronic medical record. GEP testing and CT use were compared between 3 cohorts of women defined by diagnosis: pre RS funding/pre TAILORx (before April 2014), post RS funding/pre TAILORx (April 2014-May 2018), post TAILORx (June 2018 and beyond). OFS use was compared between 2 cohorts of women defined by diagnosis pre- and post SOFT/TEXT (May 2015). In subgroup analyses, we compared CT use by GEP status and RS category and OFS use by CT status. Results: Among the 291 women identified, GEP testing increased by 37% post GEP funding (pre 2% vs. post 39%; P = &lt; .0001) and by additional 15% post TAILORx (pre 39% vs. post 54%; P &lt; .0001) whereas overall CT use declined by 15% post GEP funding (pre 85% vs. post 70%; P = .01) and by additional 16% post TAILORx (pre 70% vs. post 54%; P = .01). Although not significant, OFS use increased by 8% post SOFT/TEXT (pre 13% vs. post 21%; P = .08). In subgroup analyses, post TAILORx was associated with a significant reduction in CT use of 19.5% in non-GEP tested women (pre 85% vs. post 65% P = .01) and non-significant increase in CT use of 6% in RS tested women (pre 40% vs. post 46%; P = .61) mainly driven by high mid range RS 21-25 and lower high range RS 26-30. There was no significant change in OFS use in non-CT treated women post SOFT/TEXT (Pre 5.3% vs. Post 8%, P = .68) whereas OFS use increased by 15% in women treated with CT post SOFT/TEXT (pre 15% vs. post 30%; P = .01). Conclusions: Public GEP funding and TAILORx led to widespread adoption of GEP and real-world decline in CT use in women 40 years of age or younger diagnosed with HR+, HER2-, LN- BC in Alberta. SOFT/TEXT led to real-world incline in OFS use in those treated with CT but adoption remained suboptimal.

118P Real-world treatment patterns and clinical outcomes among high risk, early stage HER2-negative breast cancer (BC) patients in Alberta, Canada

Data are needed to improve the current understanding of the epidemiology and clinical management of high-risk early stage HER2- BC patients. This study was a retrospective longitudinal cohort study using real-world, population-level data from Alberta, Canada. All individuals newly diagnosed with high-risk, stage II/III HER2- BC in Alberta, Canada between 2013-2019 were included. Data on treatment, laboratory results and pathology findings were collected through electronic health records and administrative databases. High-risk BC was defined as receipt of adjuvant systemic therapy within 120 days of surgery as well as the presence of the following characteristics: 1) For triple-negative BC (TNBC): tumor 2+ cm (AJCC T2 or greater) or axillary lymph node (LN) involvement; 2) For hormone-receptor positive (HR+/HER2-): four or more positive LNs. Treatment eras were separated into pre/post 2016. Overall survival (OS) was defined as the date of diagnosis to death from any cause or last known contact. The annual cumulative incidence of early-stage, high-risk, HER2- BC ranged from 6% to 9%. Individuals with TNBC were more likely to be younger, have grade 3 histology, stage II BC, and receive systemic therapy at a community centre (p < 0.05) when compared with HR+/HER2- BC. Germline BRCA testing was not widely conducted in this patient population, with an estimated 14% of patients diagnosed in 2010-2017 being tested at some point post-diagnosis. Neoadjuvant systemic therapy was given to 37% of patients with high-risk BC. The 5-year OS from initiation of adjuvant systemic therapy (for patients who received adjuvant systemic therapy) or date of surgery (for patients who did not receive adjuvant systemic therapy) was 77% (95% CI: 75 to 79). OS was significantly worse among patients who were older, had grade 3 histology, stage III BC, or had LN involvement (p < 0.05). OS among patients with TNBC between 2016-2019 who initiated adjuvant capecitabine was markedly worse than that of the overall cohort (2-year OS: 70% vs. 89%). Outcomes analyses in this population suggest a continued unmet clinical need. Additional analyses into the indications for use of systemic therapies are underway.

Developing a Prediction Model for Pathologic Complete Response Following Neoadjuvant Chemotherapy in Breast Cancer: A Comparison of Model Building Approaches.

PURPOSEThe optimal characteristics among patients with breast cancer to recommend neoadjuvant chemotherapy is an active area of clinical research. We developed and compared several approaches to developing prediction models for pathologic complete response (pCR) among patients with breast cancer in Alberta.METHODSThe study included all patients with breast cancer who received neoadjuvant chemotherapy in Alberta between 2012 and 2014 identified from the Alberta Cancer Registry. Patient, tumor, and treatment data were obtained through primary chart review. pCR was defined as no residual invasive tumor at surgical excision in breast or axilla. Two types of prediction models for pCR were built: (1) expert model: variables selected on the basis of oncologists' opinions and (2) data-driven model: variables selected by trained machine. These model types were fit using logistic regression (LR), random forests (RF), and gradient-boosted trees (GBT). We compared the models using area under the receiver operating characteristic curve and integrated calibration index, and internally validated using bootstrap resampling.RESULTSA total of 363 cases were included in the analyses, of which 86 experienced pCR. The RF and GBT fits yielded higher optimism-corrected area under the receiver operating characteristic curves compared with LR for the expert (RF: 0.70; GBT: 0.69; LR: 0.65) and data-driven models (RF: 0.71; GBT: 0.68; LR: 0.64). The LR fit yielded the lowest integrated calibration indices for the expert (LR: 0.037; GBT: 0.05; RF: 0.10) and data-driven models (LR: 0.026; GBT: 0.06; RF: 0.099).CONCLUSIONOur models demonstrated predictive ability for pCR using routinely collected clinical and demographic variables. We show that machine learning fit methods can be used to optimize models for pCR prediction. We also show that additional variables beyond clinical expertise do not considerably improve predictive ability and may not be of value on the basis of the burden of data collection.

Impact of switching from digital mammography to tomosynthesis plus digital mammography on breast cancer screening in Alberta, Canada

To compare abnormal call rates (ACR), cancer detection rates (CDR), positive predictive values (PPVs), and annual return to screen recommendations after switching from digital mammography (DM) to digital breast tomosynthesis plus DM (DBT + DM) for breast cancer screening. The Alberta Breast Cancer Screening Program collects screening data from clinics throughout the province of Alberta, Canada. This study retrospectively collected data, between 2015 and 2018, on women aged 40+ who underwent breast cancer screening at two large volume multisite radiology groups to compare metrics one year prior and one year after DBT + DM implementation. Comparisons between modalities were carried out within age groups, within breast density categories, and for initial vs. subsequent screens. A total of 125,432 DM and 128,912 DBT + DM screening exams were performed. For women aged 50-74, the DBT + DM group had a higher ACR (p < 0.01) but lower annual return to screens (p < 0.01). CDR was higher post-DBT + DM implementation for women with scattered (6.0 per 1000 vs. 4.4 per 1000; p = 0.001) or heterogeneously dense breasts (6.5 per 1000 vs. 4.2 per 1000; p < 0.001). PPV was higher with DBT + DM for all age groups, with women 50-74 having a PPV of 8.3% using DBT + DM vs. 7.1% with DM (p = 0.009). All metrics improved or stayed the same after switching to DBT + DM except for ACR. However, the increase in ACR could be attributed to a trend already occurring prior to the switch. Longer term monitoring is needed to confirm these findings.

First-Line Treatment with a Cyclin-Dependent Kinase 4/6 Inhibitor Plus an Aromatase Inhibitor for Metastatic Breast Cancer in Alberta.

In this analysis, we describe population-based outcomes for first-line treatment with a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) combined with an aromatase inhibitor (AI). All patients who were prescribed CDK4/6i + AI from January 2016 through June 2019 were included. Patient demographics, tumour and treatment characteristics were collected and described. Survival distributions were estimated using the Kaplan–Meier method. Multivariate analysis (MVA) was constructed to examine associations between potentially prognostic clinical variables and progression-free survival (PFS). In total, 316 patients were included. The median age was 61 years. After a median follow-up of 28.1 months, the median PFS was 37.9 months (95% CI, 26.7–NR). In the MVA, PR-negative tumour (HR, 2.37; 95% CI, 1.45–3.88; p = 0.001) and CDK4/6i dose reduction (HR, 1.51; 95% CI, 1.06–2.16; p = 0.022) predicted worse PFS. Median overall survival (OS) was not reached. The 30-month and 36-month OS rates were 74% and 68%, respectively. Of patients who progressed, 89% received second-line treatment. Median time to progression on second-line chemotherapy was 9.0 (5.8–17.6) months, and median time to progression on second-line hormonal therapy +/− targeted agent was 4.0 (3.4–8.6) months (p = 0.012). CDK4/6i + AI as first-line treatment for HR-positive, HER2-negative MBC in Alberta is justified based on favourable PFS and early OS outcomes.

Abstract PS13-29: Four cycles of docetaxel-cyclophosphamide versus anthracycline-taxane adjuvant chemotherapy in node negative, HER2-negative breast cancer: A real-world comparison

Abstract Background: It is unknown whether four cycles of docetaxel-cyclophosphamide (DC) is an appropriate adjuvant chemotherapy option in patients with lymph node negative (LNN) and human epidermal growth factor receptor-2 (HER2) negative breast cancer in place of widely adopted anthracycline-taxane (AT) regimens. In the Canadian province of Alberta, four cycles of DC has been used preferably in the last decade as a standard adjuvant chemotherapy regimen in LNN, HER2-negative disease. We aimed to retrospectively compare the survival outcomes of patients diagnosed with LNN, HER2-negative breast cancer in Alberta who were treated with four cycles of DC as compared to those treated with an AT regimens. Methods: We identified all patients who were diagnosed with LNN, HER2-negative breast cancer treated with adjuvant chemotherapy following surgical resection in Alberta from 2008 through 2012. We used propensity score methods to match each patient treated with an AT regimen to up to 4 patients treated with four cycles of DC on all known/potential clinicopathologic and treatment variables (Table).We compared the 10-year invasive disease free survival (iDFS), breast cancer specific-survival (BCSS) and overall survival (OS) between the two patient groups and assessed effect of type of adjuvant chemotherapy on iDFS, BCSS and OS using Cox regression analyses.Results: Of the 726 eligible patients, 657 (90.5%) were treated with four cycles of DC and 69 (9.5%) were treated with an AT regimen. Prior to matching, women who received four cycles of DC compared to those treated with an AT regimen, were more likely to be older, have higher Charlson co-morbidity score and mastectomy for definitive surgery, and in terms of disease: earlier stage, lower grade, and HR-positive status. Matching created a group of 202 women treated with four cycles of DC and eliminated differences in clinicopathologic and treatment features between the two patient groups (Table). Four cycles of DC compared to an AT regimen was not associated with reduced iDFS (HR = 0.91, 95% CI = 0.52 to 1.6, P = 0.75), BCSS (HR = 1.10, 95% CI = 0.51 to 2.37, P = 0.8), or OS (HR = 1.01, 95% CI = 0.48 to 2.17, P = 0.96).Conclusion: In this real-life comparison, four cycles of DC as compared with an AT regimen, yielded similar survival outcomes amongst patients with LNN, HER2-negative breast cancer. Table Baseline patient and tumour characteristics of 726 patients diagnosed with LNN, HER2-negative breast cancer by type of adjuvant chemotherapy. CharacteristicAT (n=69)DC (n=657)p value*Matched DC (n=202)†p value‡Age (years) Median465347 Mean (SD; range)45.8 (9.7; 25 - 69)52.6 (9.8; 23 - 78)&amp;lt;0.000146 (9.4; 23 - 69)0.8BMI Median25.327.526 Mean (SD; range)27.1 (6.7;17.5 - 62)28.5 (6.6;15.6 - 64)0.127.1 (5.8;17.3- 49.4)0.9Year of diagnosis [n (%)] 2007 - 200811 (15.9%)78 (11.9%)0.2426 (13%)0.8 2009 - 201022 (31.9%)275 (41.9%)68 (33.5%) 2011 - 201236 (52.2%)304 (46.3%)108 (53%)Charlson co-morbidity score [n (%)] Mean (SD, range)0.04 (0.26; 0 - 2)0.33 (0.67; 0 - 4)&amp;lt;0.00010.04 (0.27; 0-2)0.9 Score &amp;gt; 0 - no. of patients (%)2 (2.9%)151(23%)0.00057 (3.4%)0.8 067 (97.1%)506 (77%)195 (96.6%) 11 (1.45%)97 (14.8%)4 (2%) 21 (1.45%)44 (6.7%)3 (1.4%) 309 (1.4%) 401 (0.15%)Histology [n (%)] Ductal58 (84%)479 (72.9%)0.12165 (82%)0.8 Mixed Ductal-Lobular5 (7.25%)96 (14.6%)20 (9.9%) Others6 (8.7%)82 (12.5%)17 (8.4%)T-stage [n (%)] Stage I12 (17.4%)253 (38.5%)0.000537 (18.3%)0.9 Stage II57 (82.6%)404 (61.5%)165 (81.6%)Grade differentiation [n (%)] Well differentiated026 (4%)&amp;lt;0.00700.9 Moderately differentiated6 (8.7%)139 (21.2%)20 (9.9%) Poorly differentiated63 (91.3%)492 (74.9%)182 (90.1%)Hormone receptor status [n (%)] Positive33 (47.8%)468 (71.2%)&amp;lt;0.000195 (47%)0.9 Negative36 (52.2%)189 (28.8%)107 (52.9%)Definitive breast surgery [n (%)] Breast-conserving surgery30 (43.5%)390 (59.4%)&amp;lt;0.0190 (44.5%)0.9 Mastectomy39 (56.5%)267 (40.6%)112 (55.5%)Radiotherapy [n (%)]36 (52.2%)397 (60.4%)0.18103 (51%)0.9Time interval to first cycle of chemotherapy (months) Median2.732.82.71 Mean (SD; range)2.86 (0.77; 1.2- 4.8)3.25 (1.38; 0 - 15)0.52.82 (0.8; 0– 5.9)0.7 No. of patients (%) 0 months ≥ – &amp;lt; 3 months39 (56%)404 (61.5%)0.42122 (60%)0.6 3 months ≥ – &amp;lt; 6 months30 (43.4%)245 (37.2%)80 (40%) ≥ 6 months08 (1.2%)0Type of adjuvant chemotherapy [n (%)] DC×4657 (100%)202 (100%) FEC×3→D×363 (91.3%) AC×4→T×43 (4.35%)TAC×63 (4.35%) Citation Format: Malek Bassam Hannouf, Atul Batra, Sasha Lupichuka. Four cycles of docetaxel-cyclophosphamide versus anthracycline-taxane adjuvant chemotherapy in node negative, HER2-negative breast cancer: A real-world comparison [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS13-29.

Abstract PS1-06: High-risk breast cancer in oldest old: Exploring the effect of different treatments on outcomes

Abstract Background: Octogenarians and nonagenarians diagnosed with breast cancer have a competing risk of death from other causes and their management is frequently found to be discordant with guidelines in comparison to the younger patients, particularly with low-risk disease. There is limited information about the disease trajectory and outcomes of patients with high-risk disease. Thus, this study was conducted. Methods: This is a retrospective, population-based observational study. Women aged 80 years of age or older and diagnosed with non-metastatic, high-risk breast cancer in Alberta, Canada between January 2004 and December 2017 were identified from the Alberta Cancer Registry. High-risk disease was defined as having any of the following; T3/4, any N positive, triple negative, or Her-2 positive disease. A risk scoring system was generated based on the presence of two anatomical and one biological high-risk features to generate 3 risk levels. Patients’ characteristics (age, Charlson comorbidity index, residence, education-, and income- quintiles), disease characteristics (stage, grade, receptor status,) treatment patterns (treatment delivered, facility) and survival were determined from linkage with administrative databases (Discharge Abstract Data, National Ambulatory Care Reporting System, and Vital statistics). Treatments were stratified into; none, hormonal treatment only (HT), surgery only (S), and surgery with any adjuvant treatment (S+A). Statistical methods included chi-square and Cox regression models. Association between patient, tumor and treatment variables and survival were assessed with uni- and multivariable analysis. Primary outcome was breast cancer specific survival (BCSS) in patients stratified by different risk levels in relation to the treatment delivered. Results: 1369 patients met the inclusion criteria. The median age was 84 years (interquartile range [IQR] 82-88). After a median follow-up of 35 months (m), 873 (64%) patients had died; 405 (46%) of deaths were due to breast cancer. On multivariable analysis, patients had a lower hazard of death from cancer if they were treated with S (HR = 0.51, 95%CI: 0.34, 0.77, p = 0.001) or S+A (HR = 0.41, 95%CI: 0.28, 0.6, p &amp;lt; 0.001) in comparison to HT alone. Patients who did not receive any form of treatment were more likely to die from breast cancer (HR 2.14 95%CI: 1.38, 3.31, p = 0.0006). Patients who had 1 or 2 risk features had higher cancer specific and overall survival if they had S or S+A (49/31m, 92/66m median differences respectively p &amp;lt; .0001). Those with 3 risk features showed longer survival if they received S+A (29/25m median differences p &amp;lt; .0001). Conclusions and Relevance: Our findings suggest that a significant proportion of older patients with breast cancer patients with high-risk features may have increased disease-specific mortality risk. Based on a priori risk levels, and in properly selected patients, treatment options including surgery and adjuvant treatment may be associated in longer survival. Table 1 - Population and Treatment CharacteristicsVariablesCategoryTotal (N=1369)Age group80-85817 (59.7 %)86-90388 (28.3 %)91-95146 (10.7 %)&amp;gt;9518 (1.3 %)Charlson Comorbidity Index0453 (33.1 %)1361 (26.4 %)&amp;gt;=2555 (40.5 %)TNM stageI239 (17.5 %)II663 (48.4 %)III422 (30.8 %)T stageT1416 (30.4 %)T2601 (43.9 %)T3163 (11.9 %)T4169 (12.3 %)Unknown20 (1.5 %)N stageN0526 (38.4 %)N1548 (40 %)N2159 (11.6 %)N385 (6.2 %)Unknown51 (3.7 %)Receptor statusER+orPR+andHer2-1071 (78.2 %)Her2+130 (9.5 %)ER-andPR-andHer2-123 (9 %)Unknown45 (3.3 %)Risk levels1922 (67.3 %)2371 (27.1 %)376 (5.6 %)Surgery typeNo surgery215 (15.7 %)BCS364 (26.6 %)Mastectomy790 (57.7 %)Sentinel surgeryno938 (68.5 %)yes431 (31.5 %)Chemotherapyno1337 (97.7 %)yes32 (2.3 %)Radiotherapyno991 (72.4 %)yes378 (27.6 %)Hormonotherapyno659 (48.1 %)yes710 (51.9 %) Citation Format: Abdulla Al-Rashdan, Yuan Xu, Lisa Barbera, Jeffrey Cao, Winson Cheung, Antoine Bouchard-Fortier, MayLynn Quan. High-risk breast cancer in oldest old: Exploring the effect of different treatments on outcomes [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-06.

A Patient's Perspective: Bridging the Transition Following Radiation Therapy for Patients with Breast Cancer

IntroductionAs the number of women surviving breast cancer grows, it becomes increasingly important to investigate their unique psychosocial and physical needs in the post-treatment period. The period of transition from patient to survivor is a time fraught with physical and emotional challenges. This qualitative study was conducted to gain insight into the perspective of breast cancer patients transitioning to survivorship after receiving RT in Alberta. MethodsTen patients receiving radiation therapy (RT) for breast cancer in Alberta participated in an open-ended telephone interview two to three weeks following the cessation of treatment. The data was analyzed using a qualitative interpretive phenomenological approach. Data was clustered and categorized, and emerging themes were examined. ResultsThough participants reported to be satisfied with the care and information they received, a need for more robust and detailed skin care education was identified. Patients expressed a sense of anxiety around returning to normalcy following RT, and described feeling lonely, and unsure of themselves in the post-treatment period. A post-treatment phone call may allow Radiation Therapists (RTTs) to mitigate the ongoing needs of patients in the period between their last day of treatment and their first follow-up visit. ConclusionThis project has given us an opportunity to hear the voice of the patient, thus laying the groundwork to allow for a more patient-centred approach to the transition of care following RT. The data gathered suggests possible areas for development of interventions and supports for breast cancer patients as they transition into survivorship.

Unwarranted imaging for distant metastases in patients with newly diagnosed ductal carcinoma in situ and stage I and II breast cancer

In 2012, the American Society of Clinical Oncology (ASCO) released a Choosing Wisely Top Five list that included a recommendation against ordering advanced imaging tests to screen for metastases among asymptomatic patients with early breast cancer. Our provincial breast cancer staging guideline was subsequently updated. We report on the use of unwarranted bone scanning (BS), computed tomography (CT), nonbreast magnetic resonance imaging (MRI) and positron emission tomography (PET) among women diagnosed with stage 0–II breast cancer in Alberta in 2011–2015. The cohort was retrospectively ascertained from the Alberta Cancer Registry. We used additional provincial data sources to obtain information about diagnostic imaging tests completed from biopsy to surgical date plus 4 months. The reason for each BS, CT, MRI and PET was abstracted. We calculated the frequency of advanced imaging tests completed for routine metastatic screening. Of 10 142 patients included, 2887 (28.5%) had at least 1 advanced imaging test completed for routine metastatic screening. Of these 2887 patients, 438 (15.2%) had a follow-up BS, CT, MRI or PET, and 28 patients (1.0%) had a nonbreast imageguided biopsy. Use of routine advanced imaging tests did not change clearly over time. Our results demonstrate persistent use of advanced imaging tests for routine metastatic screening among patients with stage 0–II breast cancer despite the release of the ASCO Choosing Wisely recommendations and the update of our provincial breast cancer staging guideline. Investigation of strategies for guideline translation to improve upon value-based care of patients with early breast cancer is warranted.

Re-excision and survival following breast conserving surgery in early stage breast cancer patients: a population-based study

BackgroundIncreasing population-based evidence suggests that patients who receive breast conserving surgery (BCS) plus radiotherapy have superior survival than those who receive mastectomy. It is unclear, however, how BCS followed by re-excision is associated with all-cause and breast cancer-specific mortality, and whether the BCS survival advantage is maintained if re-excision is needed. The aim of this study was to investigate the clinical, patient, provider and geographic variation associated with receipt of re-excision surgery, and to examine the relationship between re-excision and all-cause and breast cancer-specific mortality.MethodsAll women diagnosed with stage I-III breast cancer in Alberta, Canada from 2002 to 2009 were identified from the Alberta Cancer Registry, of which 11,626 were eligible for study inclusion. Type of first breast cancer surgery after diagnosis, subsequent re-excisions within 1 year, surgeon (anonymized), and hospital were obtained from provincial physician claims data. Multilevel logistic regression with surgeons and hospitals as crossed random effects was used to estimate the adjusted odds ratios of re-excision by the factors of interest. Poisson regression models were fitted to compare all-cause and breast cancer-specific mortality by surgical pattern.ResultsRe-excision surgery was received by 19% (N = 5659) of patients who initially received BCS. The adjusted odds of re-excision varied significantly by geography of surgery, and by individual surgeon among stage I and II patients beyond the variation explained by the factors investigated (Stage I OR standard deviation (SD) = 0.43; stage II OR SD = 0.39). Patients who were treated with BCS plus re-excision surgery with either mastectomy or further BCS had similar all-cause and breast cancer-specific mortality as those treated with BCS without re-excision.ConclusionThese results suggest that breast cancer patients who are treated with BCS plus re-excision surgery by either mastectomy or further BCS have similar survival as those treated with BCS without re-excision. The significant variation in the likelihood of re-excision by geography and by individual surgeon is concerning, especially given the costs to the patient associated with additional surgery and the financial costs to the health system.

Using Multilevel Models to Explain Variation in Clinical Practice: Surgeon Volume and the Surgical Treatment of Breast Cancer.

To investigate the relationship between surgeon caseload and surgery type, and variation in the surgical treatment of early stage breast cancer patients in Alberta, Canada. All women diagnosed with stage I to III breast cancer in Alberta from 2002 to 2010 were identified from the Alberta Cancer Registry. Type of surgery, surgeon (anonymized), and hospital were obtained from provincial physician claims data. Multilevel logistic regression with surgeons and hospitals as crossed random effects was used to estimate adjusted odds ratios (OR) of receiving mastectomy by surgeon volume. Empirical Bayes estimation was used to estimate adjusted OR for individual surgeons and hospitals. Mastectomy was found to be inversely related to surgeon volume among stage I and II patients. Patients whose surgery was conducted by a low-volume surgeon had twice the odds of receiving mastectomy as those that had surgery performed by a very high-volume surgeon (stage I OR 2.36, 95% confidence interval 1.40, 3.97; stage II OR 1.96, 95% confidence interval 1.13, 3.42). OR of mastectomy varied widely by individual surgeon beyond the variation explained by the factors investigated. Surgeon characteristics, including surgeon volume, are associated with surgery type received by breast cancer patients in Alberta. Significant variation in the likelihood of breast-conserving surgery (BCS) by surgeon is concerning given the potential benefits of BCS for those who are eligible.

Diagnostic delay in young women with breast cancer: A population-based analysis.

92 Background: Breast cancer in young women is aggressive. Delays in diagnosis and treatment may contribute to the worse outcomes observed in the treatment of breast cancer in young women. The purpose of this study is to determine if there was diagnostic delay for women ≤ 35 with breast cancer in Alberta. Methods: We conducted a population based analysis of all women ≤ 35 treated for breast cancer between 2007 and 2010. Patient demographics, diagnostic modality, and time to treatment (surgery and radiation) were abstracted. “Diagnostic” and “treatment” delay were defined as ≥ 90 days from first imaging to pathologic diagnosis and pathologic diagnosis to surgery. Results: One hundred and one patient charts were identified in the Alberta Cancer Registry and reviewed. Mean age at diagnosis was 31.6 (± 3.3) years. Initial imaging modality was mammogram and ultrasound in 49.5% and 46.5% of women. The median time from imaging to pathologic diagnosis was 6 days (range 0-502). Of these, 11 (10.1%) women experienced diagnostic delay, with a median delay of 131 days (range 95-502). The stage at diagnosis was not significantly different for women with and without diagnostic delay (p = 0.47). For women with diagnostic delay, the initial imaging findings were most often reported as likely benign or recommended only follow up imaging. Mean time from diagnosis to surgery was 25 (± 14) days. Of patients undergoing surgery, 25 (24.8%) had breast conserving surgery. Radiation therapy occurred at a median of 48 (range 25-204) days post operatively or post chemotherapy. Conclusions: Ten percent of women ≤ 35 with breast cancer experienced a diagnostic delay. Diagnostic delay most often occurred due to initial imaging reports of benign or negative findings. Further studies are required to determine the impact of diagnostic delay on patient outcomes.

Palliative Radiotherapy for Women with Breast Cancer

Aims Palliative radiotherapy (PRT) plays an important role in women with metastatic breast cancer. However, not all cancer patients with an indication for PRT receive it. The aim of this study was to measure the use of PRT for women who have died of breast cancer in the Canadian province of Alberta, and to identify factors that might affect this use. Materials and methods All women who died of breast cancer in Alberta between 2000 and 2004 were identified from the Alberta Cancer Registry. PRT, defined as any radiotherapy given with palliative intent, was abstracted from the radiotherapy databases of the treatment facilities of the Alberta Cancer Board (ACB). The variables evaluated were: age at death, regional health authority (RHA), driving distance to nearest radiotherapy facility, receipt of initial treatment at an ACB facility, receipt of radiotherapy as part if initial treatment, residence in a city with an ACB facility, residence in a city with radiotherapy facilities or visiting radiation oncologists, median household income, and municipality population. Backwards stepwise logistic regression was used to determine the final set of predictor variables for the use of PRT. Results In total, 1906 women were identified as having died of breast cancer between 2000 and 2004, inclusive. Of these, 50.4% received at least one course of PRT. Factors associated with not receiving PRT in the final multiple logistic regression model for women who lived outside of the cities with radiotherapy facilities were: age >75 years, community size >10 000, median income <$47 000, and residence in RHA 4. For women living in cities with radiotherapy facilities, only age was significant. Conclusions There are many factors that influence the receipt of PRT in Alberta that are unrelated to patient need. The education of physicians and patients, as well as the establishment of more radiotherapy facilities, will help to improve the use of PRT.

Natural History of In Situ Breast Cancer in a Defined Population

The entire experience of in situ breast cancer in Alberta from 1953 to 1984 was examined. Of 243 patients coded, 226 were available for review by a panel of three pathologists. In 149 cases the diagnosis of in situ disease was confirmed. One hundred and eight patients had 109 ductal carcinomas in situ, 38 patients had lobular carcinomas in situ, with 3 patients having both. A multitude of treatments was used, ranging from local excision to radical mastectomy. Survival at a mean of 6 years follow-up was equal in all groups, with only two patients with a confirmed diagnosis of ductal carcinoma in situ dying from clinically suspected systemic disease. In patients treated by local excision, ipsilateral cancers were seen in 12% of ductal carcinoma in situ patients who had local excision and 13% of patients with lobular carcinoma in situ. Contralateral metachronous invasive cancers were seen in 6% of ductal carcinoma in situ patients and 3% of lobular carcinoma in situ patients. No lymph node involvement was seen in any of these patients, either with prophylactic dissection or in follow-up. The conclusion reached was that both in situ lesions are similar in their clinical course. Lymph node dissection is not necessary. Pathologic review is critical for accurate studies, with a change in diagnosis of 36% of diagnoses. Treatment does not appear to affect prognosis. The most appropriate treatment needs to be determined in prospective randomized trials.

The increasing incidence of breast cancer in Alberta 1953-1973.

The incidence of female breast cancer in Alberta increased steadily by one case per 100,000 per year from 1953 to 1973 to a current rate of 68.6 per year when adjusted to the 1950 U.S. population. Incidence rates of breast cancer in Alberta and Saskatchewan were identical after population adjustment. The incidence increased in women over 40, implicating an increase in the postmenopausal type of breast cancer. Birth cohort analysis showed increased age-specific incidence rates in middle-aged women occurring in successive cohorts from 1903 to 1918, a result similar to that found in Saskatchewan, Connecticut, and Finland. The menopausal hook is disappearing in Alberta data, apparently due to cohort-specific increases in incidence. Possible etiological factors involved in these incidence changes are discussed; a detailed analysis of specific etiological factors is currently underway on over 3,000 patients with malignant or benign breast disease who were examined at the Dr. W. W. Cross Cancer Institute in Edmonton from 1971 to 1974.