A population-based analysis of breast cancer incidence and survival by subtype in Ontario women

Real-world comparative effectiveness and safety of Pertuzumab in patients with HER2+ metastatic breast cancer: A pan-Canadian population-based cohort study

We assessed the comparative effectiveness and safety of pertuzumab plus trastuzumab and chemotherapy versus trastuzumab and chemotherapy for patients with HER2+ metastatic breast cancer (mBC) in Canada. We conducted a population-based retrospective study of patients receiving first-line treatment for mBC across eight Canadian provinces. Patients receiving trastuzumab and chemotherapy were historical comparators, and patients receiving pertuzumab plus trastuzumab and chemotherapy were the treatment group. Patients were followed until death or up to 5 years following the start of treatment (maximum follow-up to December 31, 2019). The primary outcome was overall survival (OS). One-year cumulative incidence and RDs were calculated for safety outcomes including hospitalization, emergency department visits, febrile neutropenia, and cardiac-related events. Propensity score matching (PSM) and inverse-probability of treatment weighting (IPTW) were applied within provinces. Individual provincial survival estimates were pooled using random effects meta-analysis. 3063 patients who received first-line treatment for mBC were identified. Median OS was higher among treatment patients compared to comparator patients in most provinces. Pertuzumab was associated with a statistically significantly lower risk of mortality (pooled HRs, PSM: 0.65, 95%CI: 0.57-0.74; IPTW: 0.65, 95% CI: 0.61-0.70). The treatment group had a lower risk of hospitalization compared to the comparator group (pooled RD: -0.05, 95% CI: [-0.09]-[-0.01]). No difference in 1-year cumulative incidence of cardiac-related events was identified between groups. Pertuzumab use in practice was associated with statistically significant improved survival without apparent safety concerns among patients with mBC. Real-world evaluations allow for assessments of publicly funded treatments to inform funding policies.

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

BACKGROUND

Data 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 METHODS

This 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.

RESULTS

The 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%).

CONCLUSION

Outcomes analyses in this high-risk, HER2-negative eBC population suggest a continued unmet clinical need.

Improvement in breast cancer survival across molecular subtypes in Hungary between 2011 and 2020: a nationwide, retrospective study

Background

Despite well-documented clinical differences across breast-cancer (BC) molecular subtypes and relevant changes in therapeutic interventions over the past decades, there remains a significant lack of up-to-date epidemiologic data and real-world outcomes, particularly in Central and Eastern Europe.

Methods

This was a nationwide, retrospective study using the claims databases of the Hungarian National Health Insurance Fund (NHIF) that included patients who were newly diagnosed with BC between 2011 and 2020. BC subtypes were defined based on the therapies received. Overall survival (OS) and net survival rates were calculated.

Results

Between 2011 and 2020, 74,143 patients were newly diagnosed with BC based on ICD-10 diagnostic codes in the NHIF database and 80.1% of the cases could be classified into subtypes based on therapy. The most common subtype was HER2-/HR+ BC, identified in 61.9% of patients, followed by triple negative breast cancer (TNBC) in 8.4%, HER2+/HR+ BC in 6.2%, and HER2+/HR- BC in 3.6% of cases. The proportions of TNBC and HER2+/HR+ were higher among younger patients, than in elderly cohorts. The 5-year OS of the total BC population was 74.2% in patients diagnosed between 2015-2019. Patients with TNBC had the poorest 5-year OS (TNBC: 61.4%; HER2+/HR+: 86.5%; HER2-/HR+: 79.1%; HER2+/HR-: 71.9%). Net survival rates (i.e. survival rates after adjusting the effects of other causes of death) varied across diagnostic periods and molecular subtypes. In most cases, patients diagnosed later during the study period tended to have numerically better survival rates. Patients with HER2-/HR+ BC had the most favorable net survival, with 5-year net survival exceeding 92% during the whole observation period, while TNBC patients had the lowest 5-year net survival rates ranging between 63.6% and 65.8% during the study period.

Conclusion

Our nationwide study describes the distribution and survival of BC patients with different subtypes based on a retrospective analysis of the health insurance fund database. There remains a significant room for improvement in the survival of more aggressive molecular subtypes including HR-/HER2+ and triple-negative BC, which are more common in younger age cohorts.

Guidance for Canadian Breast Cancer Practice: National Consensus Recommendations for the Systemic Treatment of Patients with HER2+ Breast Cancer in Both the Early and Metastatic Setting

Human epidermal growth factor receptor 2-positive (HER2+) breast cancer is an aggressive subtype of breast cancer associated with a poor prognosis when sub-optimally treated. Recent advances include new and effective targeted therapies that have significantly improved outcomes for patients. Despite these advances, there are significant gaps across Canada, underscoring the need for evidence-based consensus guidance to inform treatment decisions. Addressing these gaps is crucial to ensuring that effective therapies are integrated into clinical practice, so as to improve the lives of patients affected by this aggressive form of breast cancer. The Research Excellence, Active Leadership (REAL) Canadian Breast Cancer Alliance is a standing nucleus committee of clinical-academic oncologists across Canada and Breast Cancer Canada, a patient organization. The mandate of this group is to provide evidence-based guidance on best practices in the management of patients with breast cancer. These consensus recommendations were developed using a modified Delphi process with up to three rounds of anonymous voting. Consensus was defined a priori as ≥75% of voters agreeing with the recommendation as written. There are 9 recommendations in the early setting; 7 recommendations in the metastatic setting; and 10 recommendations for patients with brain metastases.

The Landscape of Breast Cancer Molecular and Histologic Subtypes in Canada

Purpose: To characterize the histologic and molecular subtype distribution of, and survival from, breast cancer (BC) among Canadian women overall, and by stage and age at diagnosis. Methods: Invasive BC cases from the Canadian Cancer Registry for women aged 15-99 years between 2012 and 2017 in Canada, excluding Quebec, were examined using pre-existing mortality linkages. Stage at diagnosis, molecular, and histologic subtypes, and 5-year net survival (NS) by age, subtype, and stage were determined. Results: 107,271 women with BC were included. Luminal A was the most common subtype, present in increasing proportions as women aged, up to a maximum of 55% of cases in 70-74. Ductal and luminal A were most likely to be diagnosed at stage I, while HER2+ had the highest proportion of diagnosis at stage III; triple negative (TN) and unknown had the highest proportion of stage IV. For all stages combined, luminal A had a five-year NS of 98%, while TN was 74%. NS for stage I BC was 99-100% for all subtypes, excepting TN, which was 96%. Survival decreased with advancing stage, most markedly for TN, for which stage III was 47% and stage IV 7%. Survival by equivalent stage and subtype was comparable across age groups but declined in older age categories. Conclusions: The varying natural histories of BC subtypes and histologies can inform prognoses, health system economics, and screening practices. The NS of 96% or greater for stage I, regardless of subtype, highlights the importance of early detection for all subtypes of BC, especially in aggressive subtypes.

Survival, treatment patterns, and costs of HER2+ metastatic breast cancer patients in Ontario between 2005 to 2020

BACKGROUND

To enable the integration of novel therapies, it is critical to understand current long-term outcomes in HER2-positive metastatic breast cancer (mBC), including survival, treatment patterns, and costs. We sought to define these outcomes among patients with mBC in Ontario.

METHODS

We conducted a retrospective population-level study in Ontario women diagnosed with breast cancer of any stage between January 1, 2005 and December 31, 2019, with follow-up until December 31, 2020. HER2-positivity was based on receipt of a HER2-targeted therapy (HER2-TT) in the first line (1L) metastatic setting. Administrative databases at ICES were used to assess outcomes.

RESULTS

In Ontario, 2557 patients were diagnosed with mBC and received a HER2-TT, and of these 1606 were diagnosed with early-stage (stage I-III) that became metastatic (recurrent), while 951 were diagnosed with late stage/de novo mBC (stage IV). The average age of all patients was 54.8 years ± 12.7 years. Treatment regimens that included pertuzumab and trastuzumab (cohort name: pert_tras) were the most frequently used HER2-TT for 1L mBC (51.4%), while T-DM1 was the most frequent therapy (87.5%) in second line (2L). The median overall survival (mOS) from initiation of 1L pert_tras was not reached, whereas mOS from initiation of T-DM1 in 2L was 18.7 months. The overall mean cost per patient on pert_tras during 1L was $267,282. The main cost drivers were the cost of systemic therapy, followed by cancer clinic visits, with a mean cost per patient at $158,961 and $73,882, respectively.

CONCLUSION

The baseline characteristics and treatment patterns for patients who received HER2-TT in our study align with previously reported results. However, the mOS observed for 2L T-DM1 was shorter than that found in pivotal, clinical trial literature. As expected, anti-cancer systemic therapy costs were the main contributor to the over quarter-million dollar mean cost per patient on pert_tras in 1L.

The Canadian Breast Cancer Symposium 2023 Meeting Report

On 15-16 June 2023, healthcare professionals and breast cancer patients and advocates from across Canada met in Toronto, Ontario, for the 2023 Canadian Breast Cancer Symposium (CBSC.). The CBSC. is a national, multidisciplinary event that occurs every 2 years with the goal of developing a personalized approach to the management of breast cancer in Canada. Experts provided state-of-the-art information to help optimally manage breast cancer patients, including etiology, prevention, diagnosis, experimental biology, and therapy of breast cancer and premalignant breast disease. The symposium also had the objectives of increasing communication and collaboration among breast cancer healthcare providers nationwide and providing a comprehensive and real-life review of the many facets of breast cancer. The sessions covered the patient voice, the top breast cancer papers from different disciplines in 2022, artificial intelligence in breast cancer, systemic therapy updates, the management of central nervous system metastases, multidisciplinary management of ductal carcinoma in situ, special populations, optimization-based individual prognostic factors, toxicity management of novel therapeutics, survivorship, and updates in surgical oncology. The key takeaways of these sessions have been summarized in this conference report.

Successful management of bilateral orbital metastases from invasive lobular breast cancer with abemaciclib and letrozole: a case report and literature review

Breast cancer is a significant global health concern, contributing to substantial morbidity and mortality among women. Hormone receptor-positive (HR+)/HER2-negative (HER2-) breast cancer constitutes a considerable proportion of cases, and significant advancements have been made in its management. CDK4/6 inhibitors (CDK4/6is) are a new targeted therapy that has demonstrated efficacy in adjuvant, advanced and metastatic settings. The propensity of lobular breast carcinomas for estrogen-rich sites, such as periocular tissues and orbital fat, may explain their tendency for orbital metastases. Current treatment strategies for these cases are predominantly palliative, and the prognosis remains poor. This article presents a unique case of a 51-year-old female with progressive right periorbital edema, pain, and limited ocular motility. An imaging work-up showed bilateral intra and extraconal orbital infiltration, which was biopsied. The histopathologic analysis disclosed mild chronic inflammatory infiltrate with thickened fibrous tissue and moderately differentiated lobular carcinoma cells, positive for GATA3 and CK7 markers, with 100% of tumor nuclei expressing estrogen receptors (ER+). A systemic evaluation showed a multicentric nodular formation in both breasts. Further diagnostic assessments unveiled an HR+/HER2- bilateral lobular breast carcinoma with synchronous bilateral orbital metastases. Systemic treatment was initiated with abemaciclib 150mg twice daily and letrozole 2.5mg once a day. However, this regimen was interrupted due to toxicity. After two weeks, treatment was resumed with a reduced abemaciclib dose (100mg twice daily) alongside letrozole, with a reasonable tolerance. Nearly two years after the initial diagnosis of inoperable metastatic cancer, the patient remains on the same systemic treatment regimen with no signs of invasive disease. This case report is the first of a patient presenting with bilateral orbital metastases from bilateral lobular breast cancer, showing an impressive and sustained response to a first-line treatment regimen combining abemaciclib and letrozole. A literature review on bilateral orbital metastases from breast cancer is also presented.

Population-level impact of adjuvant trastuzumab emtansine on the incidence of metastatic breast cancer: an epidemiological prediction model of women with HER2-positive early breast cancer and residual disease following neoadjuvant therapy

PURPOSE

Treating early-stage breast cancer (eBC) may delay or prevent subsequent metastatic breast cancer (mBC). In the phase 3 KATHERINE study, women with human epidermal growth factor receptor 2 (HER2)-positive eBC with residual disease following neoadjuvant therapy containing trastuzumab and a taxane experienced 50% reductions in disease recurrence or death when treated with adjuvant trastuzumab emtansine (T-DM1) vs adjuvant trastuzumab. We predicted the population-level impact of adjuvant T-DM1 on mBC occurrence in five European countries (EU5) and Canada from 2021-2030.

METHODS

An epidemiological prediction model using data from national cancer registries, observational studies, and clinical trials was developed. Assuming 80% population-level uptake of adjuvant treatment, KATHERINE data were extrapolated prospectively to model projections. Robustness was evaluated in alternative scenarios.

RESULTS

We projected an eligible population of 116,335 women in Canada and the EU5 who may be diagnosed with HER2-positive eBC and have residual disease following neoadjuvant therapy from 2021-2030. In EU5, the cumulative number of women projected to experience relapsed mBC over the 10-year study period was 36,009 vs 27,143 under adjuvant trastuzumab vs T-DM1, a difference of 8,866 women, equivalent to 25% fewer cases with the use of adjuvant T-DM1 in EU5 countries from 2021-2030. Findings were similar for Canada.

CONCLUSION

Our models predicted greater reductions in the occurrence of relapsed mBC with adjuvant T-DM1 vs trastuzumab in the indicated populations in EU5 and Canada. Introduction of T-DM1 has the potential to reduce population-level disease burden of HER2-positive mBC in the geographies studied.

Updates on Triple-Negative Breast Cancer in Type 2 Diabetes Mellitus Patients: From Risk Factors to Diagnosis, Biomarkers and Therapy

Triple-negative breast cancer (TNBC) is usually the most malignant and aggressive mammary epithelial tumor characterized by the lack of expression for estrogen receptors and progesterone receptors, and the absence of epidermal growth factor receptor (HER)2 amplification. Corresponding to 15-20% of all breast cancers and well-known by its poor clinical outcome, this negative receptor expression deprives TNBC from targeted therapy and makes its management therapeutically challenging. Type 2 diabetes mellitus (T2DM) is the most common ageing metabolic disorder due to insulin deficiency or resistance resulting in hyperglycemia, hyperinsulinemia, and hyperlipidemia. Due to metabolic and hormonal imbalances, there are many interplays between both chronic disorders leading to increased risk of breast cancer, especially TNBC, diagnosed in T2DM patients. The purpose of this review is to provide up-to-date information related to epidemiology and clinicopathological features, risk factors, diagnosis, biomarkers, and current therapy/clinical trials for TNBC patients with T2DM compared to non-diabetic counterparts. Thus, in-depth investigation of the diabetic complications on TNBC onset, development, and progression and the discovery of biomarkers would improve TNBC management through early diagnosis, tailoring therapy for a better outcome of T2DM patients diagnosed with TNBC.

Targeting HER2-low in metastatic breast cancer: an evolving treatment paradigm

The results of the Phase III DESTINY-Breast04 trial of trastuzumab deruxtecan (T-DXd) are leading to a shift in both the classification and treatment of human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer. In this trial, T-DXd was associated with a substantial survival benefit among patients with hormone receptor-positive and hormone receptor-negative disease and low expression of HER2, a biomarker previously considered unactionable in this treatment setting. Herein, we discuss the evolving therapeutic pathway for HER2-low disease, ongoing clinical trials, and the potential challenges and evidence gaps arising with treatment of this patient population.

Place in Therapy of Cyclin-Dependent Kinase 4/6 Inhibitors in Breast Cancer: A Targeted Literature Review

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) are the preferred regimen for patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced or metastatic breast cancer. However, the optimal treatment sequencing for CDK4/6i with other available therapeutic options is unclear. We conducted a targeted literature review to identify the current evidence on CDK4/6i treatment patterns in patients with breast cancer. The search was initially conducted in October 2021 and subsequently updated in October 2022. Biomedical databases and gray literature were searched, and bibliographies of included reviews were screened for relevant studies. The search identified ten reviews published since 2021 and 87 clinical trials or observational studies published since 2015. The included reviews discussed CDK4/6i usage with or without endocrine therapy (ET) in first-line and second-line treatment for patients with HR+/HER2- advanced or metastatic breast cancer, followed by ET, chemotherapy, or targeted therapy with ET. Clinical studies reported similar treatment sequences consisting of ET, chemotherapy, or targeted therapy with ET prior to CDK4/6i with ET, followed by ET monotherapy, chemotherapy, targeted therapy with ET, or continued CDK4/6i with ET. Current evidence suggests CDK4/6i are effective for HR+/HER2- advanced or metastatic breast cancer in earlier lines of therapy. Efficacy of CDK4/6i as measured by progression-free survival and overall survival was similar within a line of therapy regardless of the type of prior therapy. Survival on different post-CDK4/6i treatments was also similar within the same line of therapy. Additional research is needed to investigate the optimal place in therapy of CDK4/6i and the sequencing of treatments following progression on CDK4/6i.

Erythroblastic oncogene B-2 status and intracranial metastatic disease in patients with gastrointestinal cancer: a systematic review

PURPOSE

The incidence of intracranial metastatic disease (IMD) in patients with gastrointestinal (GI) cancers is rising. Expression of the erythroblastic oncogene B-2 (ERBB2) is associated with an in increased risk of IMD in patients with breast cancer. The implications of ERBB2 expression for IMD risk in patients with GI cancers is less clear. The objective of this systematic review was to determine the incidence of IMD and OS in patients with ERBB2+ gastrointestinal cancers.

METHODS

A literature search of MEDLINE, EMBASE, CENTRAL, and grey literature sources was conducted from date of database inception to July 2021. Included studies reported outcomes on patients with IMD secondary to ERBB2 GI cancers.

RESULTS

Fourteen cohort studies met inclusion criteria, of which thirteen were retrospective. Eleven studies reported on gastric, esophageal, or gastroesophageal junction cancers. Three studies directly compared incidence of IMD based on ERBB2 status and among these, ERBB2+ patients had a higher incidence of IMD. One study indicated that ERBB2+ patients had significantly longer OS from the times of primary cancer (P = .015) and IMD diagnosis (P = .01), compared with patients with ERBB2- disease.

CONCLUSIONS

In this systematic review, patients with ERBB2+ GI cancer were more likely to develop IMD. Future study is required on the prognostic and predictive value of ERBB2 status in patients with GI cancers.

Prevalence of Breast Cancer Survivors Among Canadian Women

BACKGROUND

The 49% decrease in breast cancer mortality since 1986 has increased the number of breast cancer survivors requiring survivorship care. The purpose of this analysis was to estimate the 2022 prevalence of breast cancer survivors diagnosed within the past 15 years among Canadian women.

METHODS

We extracted the projected female breast cancer cases from 2007 to 2021 and rates of net survival (competing noncancer causes of death removed) from the Canadian Cancer Society's statistical reports. Overall survival was extracted from published Ontario data. Using known survival rates for 1, 5, 10, and 15 years, we interpolated remaining years and applied the corresponding net and overall survival rates to the projected cases for each year from 2007 to 2021 to determine survivors in 2022. Prevalence for predefined age groups was also calculated. As an example of excess healthcare costs attributable to breast cancer, we calculated the excess costs of heart failure hospitalizations.

RESULTS

From 2007 to 2021, there were 370,756 breast cancer cases. Using net survival, 318,429 (85.9%) of these patients were projected to survive breast cancer by 2022, a prevalence of 2.1% of Canadian women. Using overall survival, prevalence was 1.8%. Prevalence increased with age group, from 0.01% of those aged 20 to 24 years to 12.7% of those aged ≥90 years, and from 1.0% among the working and/or child-raising (age 20-64 years) to 5.4% among elderly populations (age ≥65 years). Among these survivors, 24.9% of projected heart failure hospitalizations would be in excess of those among matched control subjects, with projected excess costs of $16.5 million CAD. Given the excess healthcare costs, potential for reduced contributions to the workforce, and reduced quality of life associated with long-term impairments and risk of excess non-breast cancer death, enhanced breast cancer survivorship care is warranted.

CONCLUSIONS

With an overall prevalence of 2% among Canadian women, breast cancer survivors represent an increasing segment of the working-age and elderly populations.

Long-term outcomes of non-metastatic breast cancer patients by molecular subtypes

Background

Today, with the progress of medical sciences, increasing the cure probability and survival time is an important goal of cancer treatment. This study compared long-term disease-free survival (DFS) of non-metastatic breast cancer patients based on different molecular subtypes.

Methods

This retrospective cohort study consisted of 1287 patients diagnosed with breast cancer and treated at Motamed Cancer Institute from 2000 to 2016 and followed up until 2018. Kaplan–Meier curve was fitted to data based on molecular subtypes. Then the semi-parametric mixture cure model was applied to determine the survival and cure probability of molecular subtypes by adjusting clinical and demographic factors.

Results

Among 1287 breast cancer patients, 200 (15.5%) cases died. The mean age of patients was 47.00 ± 10.72 years. Women with the HR+/HER2-subtype had the best 5-year survival rate (84.2%), whereas other subtypes had a lower rate as follows: HR+/HER2+ (77.3%), triple-negative (76.5%), and HR−/HER2+ (62.3%). Kaplan–Meier curve calculated a cure rate of about 60% and patients who survived more than 150 months were intuitively considered cured. After adjustment for clinical and demographic variables, the cure probability of HR−/Her2+ patients was substantially lower than HR+/HER2– patients (OR = 0.22), though there were no significant variations in short-term DFS based on molecular subtypes (HR = 0.91).

Conclusions

Our results confirm that the most prevalent breast cancer was HR+/HER2− tumor type which had the best prognosis. It is also concluded that HR−/HER2+ patients had the worst outcomes, with the highest rates of recurrence and metastasis and the lowest overall and disease-free survival rates.

Developing the Breast Utility Instrument to Measure Health-Related Quality-of-Life Preferences in Patients with Breast Cancer: Selecting the Item for Each Dimension

Introduction. Generic preference-based instruments inadequately measure breast cancer (BrC) health-related quality-of-life preferences given advances in therapy. Our overall purpose is to develop the Breast Utility Instrument (BUI), a BrC-specific preference-based instrument. This study describes the selection of the BUI items. Methods. A total of 408 patients from diverse BrC health states completed the EORTC QLQ-C30 and BR45 (breast module). For each of 10 dimensions previously assessed with confirmatory factor analysis, we evaluated data fit to the Rasch model based on global model and item fit, including threshold ordering, item residuals, infit and outfit, differential item functioning (age), and unidimensionality. Misfitting items were removed iteratively, and the model fit was reassessed. From items fitting the Rasch model, we selected 1 item per dimension based on high patient- and clinician-rated item importance, breadth of item thresholds, and clinical relevance. Results. Global model fit was good in 7 and borderline in 3 dimensions. Separation index was acceptable in 4 dimensions. Item selection criteria were maximized for the following items: 1) physical functioning (trouble taking a long walk), 2) emotional functioning (worry), 3) social functioning (interfering with social activities), 4) pain (having pain), 5) fatigue (tired), 6) body image (dissatisfied with your body), 7) systemic therapy side effects (hair loss), 8) sexual functioning (interest in sex), 9) breast symptoms (oversensitive breast), and 10) endocrine therapy symptoms (problems with your joints). Conclusions. We propose 10 items for the BUI. Our next steps include assessing the measurement properties prior to eliciting preference weights of the BUI.

Highlights

A previous confirmatory factor analysis established 10 dimensions of the European Organisation for Research and Treatment of Cancer (EORTC) core quality of life questionnaire (QLQ-C30) and its breast module (BR45).In this study, we selected 1 item per dimension based on fit to the Rasch model, patient- and clinician-rated item importance, breadth of item thresholds, and clinical relevance.These items form the core of the future Breast Utility Instrument (BUI).The future BUI will be a novel breast cancer-specific preference-based instrument that potentially will better reflect women's preferences in clinical decision making and cost utility analyses.

Gene Mutations Associated With Clinical Characteristics in the Tumors of Patients With Breast Cancer

Background

Clinical characteristics including estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 (HER2) are important biomarkers in the treatment of breast cancer, but how genomic mutations affect their status is rarely studied. This study aimed at finding genomic mutations associated with these clinical characteristics.

Methods

There were 160 patients with breast cancer enrolled in this study. Samples from those patients were used for next-generation sequencing, targeting a panel of 624 pan-cancer genes. Short nucleotide mutations, copy number variations, and gene fusions were identified for each sample. Fisher’s exact test compared each pair of genes. A similarity score was constructed with the resulting P-values. Genes were clustered with the similarity scores. The identified gene clusters were compared to the status of clinical characteristics including ER, PR, HER2, and a family history of cancer (FH) in terms of the mutations in patients.

Results

Gene-by-gene analysis found that CCND1 mutations were positively correlated with ER status while ERBB2 and CDK12 mutations were positively correlated with HER2 status. Mutation-based clustering identified four gene clusters. Gene cluster 1 (ADGRA2, ZNF703, FGFR1, KAT6A, and POLB) was significantly associated with PR status; gene cluster 2 (COL1A1, AXIN2, ZNF217, GNAS, and BRIP1) and gene cluster 3 (FGF3, FGF4, FGF19, and CCND1) were significantly associated with ER status; gene cluster 2 was also negatively associated with a family history of cancer; and gene cluster 4 was significantly negatively associated with age. Patients were classified into four corresponding groups. Patient groups 1, 2, 3, and 4 had 24.1%, 36.5%, 38.7%, and 41.3% of patients with an FDA-recognized biomarker predictive of response to an FDA-approved drug, respectively.

Conclusion

This study identified genomic mutations positively associated with ER and PR status. These findings not only revealed candidate genes in ER and PR status maintenance but also provided potential treatment targets for patients with endocrine therapy resistance.

Cost-effectiveness Analysis of Pertuzumab With Trastuzumab in Patients With Metastatic Breast Cancer

IMPORTANCE

The initial assessment of pertuzumab use for treatment of metastatic breast cancer by health technology assessment agencies suggested that pertuzumab was not cost-effective. In Ontario, Canada, pertuzumab became funded in November 2013 based on the substantial clinical benefit. To date, there is a paucity of analysis of pertuzumab using real-world data for cost-effectiveness.

OBJECTIVE

To assess the cost-effectiveness of pertuzumab, trastuzumab, and chemotherapy vs trastuzumab and chemotherapy for patients with metastatic breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

A population-based retrospective economic evaluation was conducted in Ontario, Canada. Patients who received first-line treatments for metastatic breast cancer from January 1, 2008, to March 31, 2018, were identified. Patients were followed up from the start of treatment up to 5 years, with maximum follow-up to March 31, 2019. Patients were identified from the Ontario Cancer Registry and linked to the New Drug Funding Program database to identify receipt of first-line treatment (N = 1158).

INTERVENTIONS

Treatment with pertuzumab, trastuzumab, and chemotherapy after public funding (November 25, 2013) compared with treatment with trastuzumab and chemotherapy before funding.

MAIN OUTCOMES AND MEASURES

Cost-effectiveness, from a public payer perspective, was estimated from administrative data with a 5-year time horizon, adjusted for censoring, and discounted (1.5%). Incremental cost-effectiveness ratios for life-years gained and quality-adjusted life year (QALY) with bootstrapped 95% CIs were calculated. Sensitivity analysis with price reduction of pertuzumab alone or in combination with trastuzumab was conducted.

RESULTS

A total of 579 pairs of matched patients receiving pertuzumab and controls were included. The mean (SD) age of the matched study cohort was 58 (12.97) years; 1151 were women (99.4%). Pertuzumab resulted in 0.61 life-years gained and 0.44 QALYs gained at an incremental cost of $192 139 (all costs measured in Canadian dollar values, CAD) with an incremental cost-effectiveness ratio of $316 203 per life-year gained and $436 679 per QALY. The main factors associated with cost included the cost of pertuzumab (60%), outpatient cancer treatment delivery (24%), and trastuzumab (15%). With 100% price reduction of pertuzumab, the incremental cost-effectiveness ratio was $174 027 per QALY. When the price of pertuzumab and trastuzumab were both reduced by more than 71%, the incremental cost-effectiveness ratio decreased below $100 000 per QALY.

CONCLUSIONS AND RELEVANCE

The findings of this population-based study suggest that pertuzumab may increase survival for patients with metastatic breast cancer but would not be considered cost-effective, even after 100% price reduction, under conventional thresholds.

Safety, Feasibility, and Merits of Longitudinal Molecular Testing of Multiple Metastatic Sites to Inform mTNBC Patient Treatment in the Intensive Trial of Omics in Cancer

Patients with metastatic triple-negative breast cancer (mTNBC) have poor outcomes. The Intensive Trial of Omics in Cancer (ITOMIC) sought to determine the feasibility and potential efficacy of informing treatment decisions through multiple biopsies of mTNBC deposits longitudinally over time, accompanied by analysis using a distributed network of experts.

In the Intensive Trial of Omics in Cancer (ITOMIC), the feasibility and potential efficacy of informing treatment decisions through omics analysis of multiple biopsies of mTNBC deposits over time was assessed. An ITOMIC Tumor Board (ITB) that comprised experts discussed tumor profile findings and made treatment recommendations to each subject's physician. Study-directed omics analysis revealed that of the 31 enrolled subjects, two were found to have lung cancer, one a carcinoma of unknown primary site that and tumor samples from five subjects showed some receptor-positivity. Several subjects survived well beyond what would be expected for this patient group, supporting the merits of further investigation of this approach.

Developing the Breast Utility Instrument, a preference-based instrument to measure health-related quality of life in women with breast cancer: Confirmatory factor analysis of the EORTC QLQ-C30 and BR45 to establish dimensions

OBJECTIVES

Breast cancer (BrC) and its treatments impair health-related quality of life (HRQoL). Utility is a measure of HRQoL that includes preferences for health outcomes, used in treatment decision-making. Generic preference-based instruments lack BrC-specific concerns, indicating the need for a BrC-specific preference-based instrument. Our objective was to determine dimensions of the European Organisation for Research and Treatment of Cancer (EORTC) general cancer (QLQ-C30) and breast module (BR45) instruments, the first step in our development of the novel Breast Utility Instrument (BUI).

METHODS

Patients (n = 408) attending outpatient BrC clinics at an urban cancer centre, and representing a spectrum of BrC health states, completed the QLQ-C30 and BR45. We performed confirmatory factor analysis of the combined QLQ-C30 and BR45 using mean-and variance-adjusted unweighted least squares estimation. The hypothesized factor model was based on clinical relevance, item distributions, missing data, item-importance, and internal reliability of dimensions. Models were evaluated based on global and item fit, local areas of strain, and likelihood ratio tests of nested models.

RESULTS

Our final model had 10 dimensions: physical and role functioning, emotional functioning, social functioning, body image, pain, fatigue, systemic therapy side effects, sexual functioning and enjoyment, arm and breast symptoms, and endocrine therapy symptoms. Good overall model fit was achieved: χ2/df: 1.45, Tucker-Lewis index: 0.946, comparative fit index: 0.951, standardized root-mean-square residual: 0.069, root-mean-square error of approximation: 0.033 (0.030-0.037). All items had salient factor loadings (λ>0.4, p<0.001).

CONCLUSIONS

We identified important BrC HRQoL dimensions to develop the BUI, a BrC-specific preference-based instrument.

A phase II study of sequential treatment with anthracycline and taxane followed by eribulin in patients with HER2-negative, locally advanced breast cancer (JBCRG-17)

Purpose

The sequence of taxanes (T) followed by anthracyclines (A) as neoadjuvant chemotherapy has been the standard of care for almost 20 years for locally advanced breast cancer (LABC). Sequential administration of eribulin (E) following A/T could provide a greater response rate for women with LABC.

Methods

In this single-arm, multicenter, Phase II prospective study, the patients received 4 cycles of the FEC regimen and 4 cycles of taxane. After the A/T-regimen, 4 cycles of E were administered followed by surgical resection. The primary endpoint was the clinical response rate. Eligible patients were women aged 20 years or older, with histologically confirmed invasive breast cancer, clinical Stage IIIA (T2–3 and N2 only), Stage IIIB, and Stage IIIC, HER2-negative.

Results

A preplanned interim analysis aimed to validate the trial assumptions was conducted after treatment of 20 patients and demonstrated that clinical progressive disease rates in the E phase were significantly higher (30%) than assumed. Therefore, the Independent Data Monitoring Committee recommended stopping the study. Finally, 53 patients were enrolled, and 26 patients received the A/T/E-regimen. The overall observed clinical response rate (RR) was 73% (19/26); RRs were 77% (20/26) in the AT phase and 23% (6/26) in the E phase. Thirty percent (8/26) of patients had PD in the E phase, 6 of whom had achieved cCR/PR in the AT phase. Reported grade ≥ 3 AEs related to E were neutropenia (42%), white blood cell count decrease (27%), febrile neutropenia (7.6%), weight gain (3.8%), and weight loss (3.8%).

Conclusion

Sequential administration of eribulin after the A/T-regimen provided no additional effect for LABC patients. Future research should continue to focus on identifying specific molecular biomarkers that can improve response rates.

Treatment Patterns and Outcomes of Women with Symptomatic and Asymptomatic Breast Cancer Brain Metastases: A Single-Center Retrospective Study

BACKGROUND

Breast cancer is the most common cancer among women worldwide and the second leading cause of brain metastases (BrM). We assessed the treatment patterns and outcomes of women treated for breast cancer BrM at our institution in the modern era of stereotactic radiosurgery (SRS).

MATERIALS AND METHODS

We conducted a retrospective analysis of women (≥18 years of age) with metastatic breast cancer who were treated with surgery, whole brain radiotherapy (WBRT), or SRS to the brain at the Sunnybrook Odette Cancer Centre, Toronto, Canada, between 2008 and 2018. Patients with a history of other malignancies and those with an uncertain date of diagnosis of BrM were excluded. Descriptive statistics were generated and survival analyses were performed with subgroup analyses by breast cancer subtype.

RESULTS

Among 683 eligible patients, 153 (22.4%) had triple-negative breast cancer, 188 (27.5%) had HER2+, 246 (36.0%) had hormone receptor (HR)+/HER2-, and 61 (13.3%) had breast cancer of an unknown subtype. The majority of patients received first-line WBRT (n = 459, 67.2%) or SRS (n = 126, 18.4%). The median brain-specific progression-free survival and median overall survival (OS) were 4.1 months (interquartile range [IQR] 1.0-9.6 months) and 5.1 months (IQR 2.0-11.7 months) in the overall patent population, respectively. Age >60 years, presence of neurological symptoms at BrM diagnosis, first-line WBRT, and HER2- subtype were independently prognostic for shorter OS.

CONCLUSION

Despite the use of SRS, outcomes among patients with breast cancer BrM remain poor. Strategies for early detection of BrM and central nervous system-active systemic therapies warrant further investigation.

IMPLICATIONS FOR PRACTICE

Although triple-negative breast cancer and HER2+ breast cancer have a predilection for metastasis to the central nervous system (CNS), patients with hormone receptor-positive/HER2- breast cancer represent a high proportion of patients with breast cancer brain metastases (BrM). Hence, clinical trials should include patients with BrM and evaluate CNS-specific activity of novel systemic therapies when feasible, irrespective of breast cancer subtype. In addition, given that symptomatic BrM are associated with shorter survival, this study suggests that screening programs for the early detection and treatment of breast cancer BrM warrant further investigation in an era of minimally toxic stereotactic radiosurgery.

Actuarial Analysis of Survival among Breast Cancer Patients in Lithuania

Breast cancer is the most common cause of mortality due to cancer for women both in Lithuania and worldwide. Chances of survival after diagnosis differ significantly depending on the stage of disease at the time of diagnosis. Extended term periods are required to estimate survival of, e.g., 15–20 years. Moreover, since mortality of the average population changes with time, estimates of survival of cancer patients derived after a long period of observation can become outdated and can be no longer used to estimate survival of patients who were diagnosed later. Therefore, it can be useful to construct analytic functions that describe survival probabilities. Shorter periods of observation can be enough for such construction. We used the data collected by the Lithuanian Cancer Registry for our analysis. We estimated the chances of survival for up to 5 years after patients were diagnosed with breast cancer in Lithuania. Then we found analytic survival functions which best fit the observed data. At the end of this paper, we provided some examples for applications and directions for further research. We used mainly the Kaplan–Meier method for our study.

A population-based comparison of treatment, resource utilization, and costs by cancer stage for Ontario patients with HER2-positive breast cancer

PURPOSE

We sought to expand the currently limited, Canadian, population-based data on the characteristics, treatment pathways, and health care costs according to stage in patients with human epidermal growth factor receptor-2 positive (HER2+) breast cancer (BC).

METHODS

We extracted data from the publicly funded health care system in Ontario. Baseline characteristics, treatment patterns, and health care costs were descriptively compared by cancer stage (I-III vs. IV) for adult women diagnosed with invasive HER2+ BC between 2012 and 2016. Resource use was multiplied by unit costs for publicly funded health care services to calculate costs.

RESULTS

Overall, 4535 patients with stage I-III and 354 with stage IV HER2+ BC were identified. Most patients with stage I-III disease were treated with surgery (4372, 96.4%), with the majority having a lumpectomy, and 3521 (77.6%) received radiation. Neoadjuvant (NAT) and adjuvant (AT) systemic treatment rates were 20.1% (n = 920) and 88.8% (n = 3065), respectively. Systemic treatment was received by 311 patients (87.9%) with metastatic HER2+ BC, 264 of whom (84.9%) received trastuzumab. Annual health care costs per patient were nearly 3 times higher for stage IV vs. stage I-III HER2+ BC.

CONCLUSION

Per-patient annual costs were substantially higher for women with metastatic HER2+ BC, despite less frequent exposure to surgery and radiation compared to those with early stage disease. Increasing NAT rates in early stage disease represent a critical opportunity to prevent recurrence and reduce the costs associated with treating metastatic HER2+ BC.

Real-World Palbociclib Use in HR+/HER2- Advanced Breast Cancer in Canada: The IRIS Study

BACKGROUND

Palbociclib is a selective cyclin-dependent kinase (CDK) 4/6 inhibitor used in combination with aromatase inhibitors or fulvestrant for patients with hormone receptor-positive (HR+) human epidermal growth factor receptor 2 (HER2)-negative advanced/metastatic breast cancer (ABC/MBC). Palbociclib was the first CDK 4/6 inhibitor approved for HR+/HER2- ABC/MBC treatment in Canada in combination with letrozole (P+L) as an initial endocrine-based therapy (approved March 2016), or with fulvestrant (P+F) following disease progression after prior endocrine therapy (approved May 2017). The Ibrance Real World Insights (IRIS) study (NCT03159195) collected real-world outcomes data for palbociclib-treated patients in several countries, including Canada.

METHODS

This retrospective chart review included women with HR+/HER2- ABC/MBC receiving P+L or P+F in Canada. Physicians reviewed medical records for up to 14 patients, abstracting demographic and clinical characteristics, treatment patterns, and clinical outcomes. Progression-free rates (PFRs) and survival rates (SRs) at 6, 12, 18, and 24 months were estimated via Kaplan-Meier analysis.

RESULTS

Thirty-three physicians examined medical records for 247 patients (P+L, n = 214; P+F, n = 33). Median follow-up was 8.8 months for P+L and 7.0 months for P+F. Most patients were initiated on palbociclib 125 mg/d (P+L, 90.2%; P+F, 84.8%). Doses were reduced in 16.6% of P+L and 14.3% of P+F patients initiating palbociclib at 125 mg/d. The PFR for P+L was 90.3% at 12 months and 78.2% at 18 months; corresponding SRs were 95.6% and 93.0%. For P+F, 6-month PFR was 91.0%; 12-month SR was 100.0%.

CONCLUSIONS

Dose reduction rates were low and PFR and SR were high in this Canadian real-world assessment of P+L and P+F treatments, suggesting that palbociclib combinations are well tolerated and effective.

A population-based comparison of treatment patterns, resource utilization, and costs by cancer stage for Ontario patients with hormone receptor-positive/HER2-negative breast cancer

PURPOSE

To update and expand on data related to treatment, resource utilization, and costs by cancer stage in Canadian patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer (BC).

METHODS

We analyzed data for adult women diagnosed with invasive HR+/HER2- BC between 2012 and 2016 utilizing the publicly funded health care system in Ontario. Baseline characteristics, treatment received, and health care use were descriptively compared by cancer stage (I-III vs. IV). Resource use was multiplied by unit costs for publicly funded health care services to calculate costs.

RESULTS

Our study included 21,360 patients with stage I-III plus 813 with stage IV HR+/HER2- BC. Surgery was performed on 20,510 patients with stage I-III disease (96.0%), with the majority having a lumpectomy, and radiation was received by 15,934 (74.6%). Few (n = 1601, 7.8%) received neoadjuvant and most (n = 15,655, 76.3%) received adjuvant systemic treatment. Seven hundred and fifty eight patients with metastatic disease (93.2%) received systemic therapy; 542 (66.7%) received endocrine therapy. Annual per patient health care costs were three times higher in the stage IV vs. stage I-III cohort with inpatient hospital services representing nearly 40% of total costs.

CONCLUSION

The costs associated with metastatic HR+/HER2- BC reflect a significant disease burden. Low endocrine treatment rates captured by the publicly funded system suggest guideline non-adherence or that a fair portion of Ontarian patients may be incurring out-of-pocket drug costs.