Disparities in Use of Human Epidermal Growth Hormone Receptor 2-Targeted Therapy for Early-Stage Breast Cancer

Emerging Data and Current Challenges for Young, Old, Obese, or Male Patients with Breast Cancer

There are distinct subgroups of patients who have historically been underrepresented in most prospective clinical trials in breast cancer, including the youngest and oldest patients, male patients, and those struggling with obesity. Herein, we review current and future directions in research for each of these special populations with breast cancer, highlighting significant knowledge gaps and priorities in tumor biology and heterogeneity, therapeutic decision making promotion of adherence, supportive care, and psychosocial and functional well-being. In younger women, future study should focus on the biological underpinnings of aggressive disease and optimizing adherence and treatment decision making while addressing their unique survivorship needs. The latter includes generating a scientific basis for interruption of therapy for pregnancy. Among older patients, interventions should focus on increasing clinical trial accrual, predicting and mitigating toxicity so that functional status can be optimized, tailoring needs for dose modification, and anticipating life expectancy in the context of competing causes of death. For men with breast cancer, we need worldwide collaboration to answer even basic questions on optimal treatment, supportive care, and survivorship strategies. Finally, for those struggling with obesity, we need to better understand the biological associations with cancer incidence, prognosis and outcome, and how we can best intervene to assure weight loss at the "right time." It is only through highly collaborative, far-reaching, prospective, multidisciplinary, patient-centered, and patient-engaged efforts that we can optimize the physical and psychologic outcomes for all patients with breast cancer. Clin Cancer Res; 23(11); 2647-54. ©2017 AACRSee all articles in this CCR Focus section, "Breast Cancer Research: From Base Pairs to Populations."

Factors That Contributed to Black-White Disparities in Survival Among Nonelderly Women With Breast Cancer Between 2004 and 2013

Purpose

To estimate the contribution of differences in demographics, comorbidity, insurance, tumor characteristics, and treatment to the overall mortality disparity between nonelderly black and white women diagnosed with early-stage breast cancer.

Patients and Methods

Excess relative risk of all-cause death in black versus white women diagnosed with stage I to III breast cancer, expressed as a percentage and stratified by hormone receptor status for each variable (demographics, comorbidity, insurance, tumor characteristics, and treatment) in sequentially, propensity-scored, optimally matched patients by using multivariable hazard ratios (HRs).

Results

We identified 563,497 white and black women 18 to 64 years of age diagnosed with stage I to III breast cancer from 2004 to 2013 in the National Cancer Data Base. Among women with hormone receptor–positive disease, who represented 78.5% of all patients, the HR for death in black versus white women in the demographics-matched model was 2.05 (95% CI, 1.94 to 2.17). The HR decreased to 1.93 (95% CI, 1.83 to 2.04), 1.54 (95% CI, 1.47 to 1.62), 1.30 (95% CI, 1.24 to 1.36), and 1.25 (95% CI, 1.19 to 1.31) when sequentially matched for comorbidity, insurance, tumor characteristics, and treatment, respectively. These factors combined accounted for 76.3% of the total excess risk of death in black patients; insurance accounted for 37.0% of the total excess, followed by tumor characteristics (23.2%), comorbidities (11.3%), and treatment (4.8%). Results generally were similar among women with hormone receptor–negative disease, although the HRs were substantially smaller.

Conclusion

Matching by insurance explained one third of the excess risk of death among nonelderly black versus white women diagnosed with early-stage breast cancer; matching by tumor characteristics explained approximately one fifth of the excess risk. Efforts to focus on equalization of access to care could substantially reduce ethnic/racial disparities in overall survival among nonelderly women diagnosed with breast cancer.

Racial-Ethnic Disparities in Uptake of New Hepatitis C Drugs in Medicare

BACKGROUND

Chronic hepatitis C is an important public health concern. Recently launched drugs to treat hepatitis C virus (HCV) infection are effective but costly. Uptake of innovative and expensive prescription drugs may not be even across patient groups. We examined racial-ethnic disparities in uptake of new HCV drugs in the first year of their use (year 2014) in Medicare.

METHODS

The study population was Medicare beneficiaries who had chronic hepatitis C in 2013 or 2014 and who were continuously enrolled in Part D stand-alone Prescription Drug Plans in 2014. We examined trends in monthly uptake of new HCV drugs and adjusted annual uptake rates by race. We used logistic regressions to obtain adjusted odds ratios and adjusted differences in annual uptake rates.

RESULTS

Monthly uptake of new HCV drugs was lower among Black Medicare patients than Whites or Hispanics in 2014. The racial gap in monthly uptake became narrower toward the end of the year. Adjusted odds of using new HCV drugs were 11% lower for Blacks with cirrhosis than Whites (odds ratio (OR) = 0.89; 95% confidence interval (CI), 0.84-0.95), and 16% lower for Blacks with HCV/HIV coinfection than Whites (OR = 0.81; 95% CI, 0.72-0.92). Annual uptake rates were not significantly different for Whites and Hispanics.

CONCLUSIONS

Black Medicare patients with cirrhosis or HCV/HIV coinfection had lower uptake rates than Whites in 2014. As utilization of new HCV drugs increases, continuing efforts will be necessary to ensure equal delivery of the drugs.

Comparative Toxicity and Effectiveness of Trastuzumab-Based Chemotherapy Regimens in Older Women With Early-Stage Breast Cancer

Purpose The combination of chemotherapy and trastuzumab is the standard of care for adjuvant treatment of human epidermal growth factor receptor 2-positive breast cancer. Two regimens have been widely adopted in the United States: doxorubicin, cyclophosphamide, paclitaxel, and trastuzumab (ACTH) and docetaxel, carboplatin, and trastuzumab (TCH). No head-to-head comparison of these regimens has been conducted in a clinical trial, and existing trial data have limited generalizability to older patients. Methods We used SEER-Medicare data from 2005 to 2013 to compare outcomes of ACTH versus TCH among patients age older than 65 years. Propensity score matching was used to balance cohort characteristics between treatment arms. Outcomes included toxicity-related hospitalization, survival, and trastuzumab completion. Data from 1,077 patients receiving ACTH or TCH were analyzed, and the propensity-matched subsample included 416 women. Results There was a significant shift toward TCH over time, with 88% of patients receiving ACTH in 2005 compared with 15% by 2011. Among propensity score-matched patients, we found no difference between regimens in health care use overall or for chemotherapy-related adverse events (ACTH, 34% v TCH, 36.5%; P = .46). Patients receiving TCH were significantly more likely to complete trastuzumab (89% v 77%; P = .001). There was no difference in 5-year breast cancer-specific survival (ACTH, 92% v TCH, 96%; hazard ratio, 2.08; 95% CI, 0.90 to 4.82) or overall survival. Conclusion Among a matched sample of older patients, ACTH compared with TCH was not associated with a higher rate of serious adverse events or hospitalizations, but it was associated with less completion of adjuvant trastuzumab. We did not detect a difference in 5-year survival outcomes for ACTH compared with TCH. In the context of limited evidence in older patients, selection between these two regimens on the basis of concerns about differential toxicity or efficacy may not be appropriate.

Disparities of Trastuzumab Use in Resource-Limited or Resource-Abundant Regions and Its Survival Benefit on HER2 Positive Breast Cancer: A Real-World Study from China

BACKGROUND

Trastuzumab is a key component of therapy for human epidermal growth receptor 2 (HER2) positive breast cancer. Because real-world data are lacking, the present research was conducted to evaluate the actual use of and the effectiveness of trastuzumab in the real world in China.

METHODS

Inpatients with HER2 positive invasive breast cancer from 13 hospitals in Eastern China (2010-2015, n = 1,139) were included in this study. We aimed to assess the actual use of trastuzumab and to evaluate potential efficacy from trastuzumab in real-world research.

RESULTS

Of 1,017 patients with early stage breast cancer (EBC), 40.5% (412/1,017) received trastuzumab therapy. Patients with EBC in resource-abundant regions (gross domestic product per capita >$15,000 and trastuzumab included in Medicare) are more likely to receive trastuzumab than those in resource-limited regions (37.3% vs. 13.0%, p < .05). After metastasis, 50.8% (366/720) patients received trastuzumab as their first-line therapy. More than 10% of patients with metastatic breast cancer (MBC) continued trastuzumab therapy after twice progression in resource-abundant regions, whereas more than 40% of patients never received any trastuzumab therapy during the whole course of therapy in resource-limited regions. Overall, the improvement in survival for trastuzumab versus non-trastuzumab was substantial in EBC (hazard ratio [HR] = 0.609, 95% confidence interval [CI]: 0.505-0.744) and in MBC (HR = 0.541, 95% CI: 0.418-0.606). This association was greater for patients with MBC who had never received trastuzumab (HR = 0.493, 95% CI: 0.372-0.576) than for those who had received adequate trastuzumab therapy in EBC stage (HR = 0.878, 95% CI: 0.506-1.431).

CONCLUSION

This study showed great disparities in trastuzumab use in different regions and different treatment stages. Both EBC and MBC patients can benefit from trastuzumab, as the survival data show; however, when trastuzumab is adequate in the early stage, a further trastuzumab-based therapy in first-line treatment of MBC will be ineffective, especially for those with short disease-free survival, and a second line of anti-HER2 therapy will be recommended. (Research number: CSCO-BC RWS 15001).

IMPLICATIONS FOR PRACTICE

This article explores the disparities in the rates of trastuzumab use due to the inequitable allocation of medical resources in China. The irrational use can be found both in resource-abundant regions and in resource-limited regions. Although trastuzumab-based therapy improved survival, the actual use of trastuzumab in the early stage of breast cancer may influence the subsequent therapeutic effect after metastasis. These findings from real-world research could help to optimize HER2 therapy after metastasis, especially in regions with limited access to these expensive targeted drugs.

Changing Natural History of HER2-Positive Breast Cancer Metastatic to the Brain in the Era of New Targeted Therapies

BACKGROUND

Given the wide adoption of human epidermal growth factor receptor 2 (HER2)-targeted therapies for advanced HER2-positive breast cancer, we studied the natural history of patients with HER2-positive breast cancer brain metastases (BCBM) over time.

PATIENTS AND METHODS

Patients with HER2-positive BCBM identified from a prospectively maintained database at the University of North Carolina were divided into 3 cohorts by year of BCBM diagnosis. Cohorts were selected by year of HER2-targeted therapy US Food and Drug Administration approval. Overall survival (OS), time to first metastasis, time to BCBM, and BCBM survival were estimated by the Kaplan-Meier method. Associations between OS after BCBM and clinical variables were assessed by Cox proportional hazards regression models.

RESULTS

One hundred twenty-three patients were identified. Median age was 51 years, and 58% were white and 31% African American. OS from initial breast cancer diagnosis improved over time: 3.6 years (95% confidence interval [CI], 2.8-6.1) in the 1998-2007 cohort, 6.6 years (95% CI, 4.5-8.6) in the 2008-2012 cohort, and 7.6 years (95% CI, 4.4-9.6) in the 2013-2015 cohort (P = .05). While time from initial diagnosis to first metastasis did not differ (P = .12), time to BCBM increased over time (2.6 years [95% CI, 1.3-3.5] for 1998-2007; 2.6 years [95% CI, 2.1-4.3] for 2008-2012, and 3.3 years [95% CI, 2.2-6] for 2013-2015; P = .05). Although OS from BCBM did not significantly differ by cohort, patients who received HER2-targeted therapy after BCBM had a prolonged OS (2.1 years [95% CI, 1.6-2.6] vs. 0.65 years [95% CI, 0.4-1.3]; P = .001).

CONCLUSION

OS from initial breast cancer diagnosis significantly improved over time for patients with HER2-positive breast cancer who develop BCBM, now exceeding 7 years; survival from BCBM diagnosis may now exceed 2 years.

Breast Cancer Disparities at Home and Abroad: A Review of the Challenges and Opportunities for System-Level Change

Sizeable disparities exist in breast cancer outcomes, both between Black and White patients in the United States, and between patients in the United States and other high-income countries compared with low- and middle-income countries (LMIC). In both settings, health system factors are key drivers of disparities. In the United States, Black women are more likely to die of breast cancer than Whites and have poorer outcomes, even among patients with similar stage and tumor subtype. Over-representation of higher risk "triple-negative" breast cancers contributes to breast cancer mortality in Black women; however, the greatest survival disparities occur within the good-prognosis hormone receptor-positive (HR+) subtypes. Disparities in access to treatment within the complex U.S. health system may be responsible for a substantial portion of these differences in survival. In LMICs, breast cancer mortality rates are substantially higher than in the United States, whereas incidence continues to rise. This mortality burden is largely attributable to health system factors, including late-stage presentation at diagnosis and lack of availability of systemic therapy. This article will review the existing evidence for how health system factors in the United States contribute to breast cancer disparities, discuss methods for studying the relationship of health system factors to racial disparities, and provide examples of health system interventions that show promise for mitigating breast cancer disparities. We will then review evidence of global breast cancer disparities in LMICs, the treatment factors that contribute to these disparities, and actions being taken to combat breast cancer disparities around the world. Clin Cancer Res; 23(11); 2655-64. ©2017 AACRSee all articles in this CCR Focus section, "Breast Cancer Research: From Base Pairs to Populations."

Initiation of Trastuzumab by Women Younger Than 64 Years for Adjuvant Treatment of Stage I-III Breast Cancer

Purpose: Studies have reported disparities by age and race in the initiation of adjuvant trastuzumab for the initial treatment of older women with early-stage breast cancer, but less is known about its initiation in younger patients. Therefore, we assessed temporal trends and clinical and demographic factors associated with trastuzumab initiation in a large, population-based cohort of patients aged <64 years in 5 states. Methods: Using a cancer registry and claims-linked data set of 13,398 women with incident invasive breast cancer from 2006 to 2011, we identified 934 patients aged <64 years with HER2-positive stage I-III breast cancer. We assessed trastuzumab initiation within the first 9 months after diagnosis and conducted logistic regression analyses to assess sociodemographic and clinical factors associated with trastuzumab initiation. Results: From 2006 to 2011, trastuzumab initiation steadily increased in patients with node-positive (from 65% to 91%) and node-negative (from 39% to 75%) breast cancers. Several tumor-related factors were associated with trastuzumab initiation, including high histologic grades (adjusted odds ratio [aOR], 6.43; 95% CI, 3.27-12.65; and aOR, 3.25; 95% CI, 1.66-6.36, for grades 3 and 2, respectively), node-positive status (aOR, 1.88; 95% CI, 1.28-2.78; P=.001), tumor size >2 cm (aOR, 1.50; 95% CI, 1.04-2.16; P=.03), and hormone receptor-negative status (aOR, 1.51; 95% CI, 1.01-2.26; P=.04). We found a null effect of race. Conclusions: Adjuvant trastuzumab therapy for early-stage breast cancer has been widely disseminated among women aged <64 years. The initiation of this targeted therapy was associated with higher-risk features, consistent with practice guidelines.

4th symposium on primary breast cancer in older women. Theme: putting personalized care into practice (Held: 3 March 2017)

Following the inception in 2010, the University of Nottingham hosted the 4th Symposium on Primary Breast Cancer in Older Women, under the auspices of the International Society of Geriatric Oncology, in March 2017, at East Midlands Conference Centre.  This is the only meeting of its kind in the UK, now held biennially, aiming at a multidisciplinary audience, including patients, their carers and advocates.  With a theme on ‘Putting personalising care into practice’, this Symposium included sessions on ‘local and systemic therapies’, ‘new ideas’, ‘patients and carers’, and ‘challenging areas’, covered by an international and local faculty, interviewing patients and carers, and abstract presentations.  Topics covered were practical and wide-ranging, including selectng for chemotherapy, radiotherapy and breast reconstruction, treating HER2-positive disease, and the roles of the geriatrician and geriatric oncology nurse.

Evolving landscape of human epidermal growth factor receptor 2-positive breast cancer treatment and the future of biosimilars

Human epidermal growth factor receptor 2-positive (HER2+) breast cancer comprises approximately 15%-20% of all breast cancers and is associated with a poor prognosis. The introduction of anti-HER2 therapy has significantly improved clinical outcomes for patients with HER2+ breast cancer, and multiple HER2-directed agents (ie, trastuzumab, pertuzumab, lapatinib, and ado-trastuzumab emtansine [T-DM1]) are approved for clinical use in various settings. The treatment landscape for patients with HER2+ breast cancer is continuing to evolve. While novel agents and therapeutic strategies are emerging, biologic therapies, particularly trastuzumab, are likely to remain a mainstay of treatment. However, access issues create barriers to the use of biologics, and there is evidence for underuse of trastuzumab worldwide. A biosimilar is a biologic product that is highly similar to a licensed biologic in terms of product safety and effectiveness. Biosimilars of trastuzumab are in development and may soon become available. The introduction of biosimilars may improve access to anti-HER2 therapies by providing additional treatment options and lower-cost alternatives. Because HER2-targeted drugs may be administered for extended periods of time and in combination with other systemic therapies, biosimilars have the potential to result in significant savings for healthcare systems. Herein we review current and emerging treatment options for, and discuss the possible role of biosimilars in, treating patients with HER2+ breast cancer.

Treatment of early-stage human epidermal growth factor 2-positive cancers among medicare enrollees: age and race strongly associated with non-use of trastuzumab

Adjuvant trastuzumab for human epidermal growth factor receptor-2 (HER2)-positive breast cancer is highly efficacious regardless of age. Recent data suggested that many older patients with HER2-positive disease do not receive adjuvant trastuzumab. Nevertheless, some of this 'under-treatment' may be clinically appropriate. We used Surveillance, Epidemiology and End Results (SEER)-Medicare data to identify patients aged ≥ 66 with stage ≥ Ib-III, HER2-positive breast cancer diagnosed during 2010-2011 (HER2 status available) who did not have a history of congestive heart failure. We described all systemic treatments received and sociodemographic and clinical characteristics associated with treatment patterns. Among 770 women 44.4 % did not receive trastuzumab, including 21.8 % who received endocrine therapy only, 6.3 % who received chemotherapy (±endocrine therapy) and 16.2 % who did not receive any systemic therapy. In addition to age and grade, race was strongly associated with non-use of trastuzumab (64.4 % of Non-Hispanic blacks vs. 43.6 % of whites did not receive trastuzumab, adjusted ORNon-Hispanic black vs. white = 3.14, 95 %CI = 1.38-7.17), and many patients with stage III disease did not receive trastuzumab. Further, 16.2 % of patients did not receive any systemic treatment and this occurred more frequently for black patients. Over 40 % of older patients with indication to receive adjuvant trastuzumab did not receive it and nearly 20 % of these patients did not receive any other treatment. Although treatment omission may be appropriate in some cases, we observed concerning differences in trastuzumab receipt, particularly for black women. Strategies to optimize care for older patients and to eliminate treatment disparities are urgently needed.

Precision medicine in acute myeloid leukemia: Hope, hype or both?

Precision medicine is interchangeably used with personalized medicine, genomic medicine and individualized medicine. Collectively, these terms refer to at least 5 distinct concepts in the context of AML. 1st, using molecular or omics data (e.g. genomics, epigenomics, transcriptomics, proteomics) to delineate or define subtypes of AML. 2nd, using these data to select the best therapy for someone with an AML subtype, such as a person with a FLT3-mutation. 3rd, using these data to monitor therapy-response such as measurable residual disease [MRD]-testing. 4th, using results of MRD-testing to select from amongst therapy-options such as additional chemotherapy or a haematopoietic cell transplant. And 5th, using these data to identify persons with hereditary forms of AML with potential therapy and surveillance implications. Here, we review these 5 conceptions and delineate where precision medicine is likely to afford greatest hope and where instead our rhetoric may constitute hype.