Factors Associated With Immunotherapy Use Among Newly Diagnosed Cancer Patients

Clinical, sociodemographic, and facility-related determinants of immunotherapy use in metastatic triple-negative breast cancer

PURPOSE

Immunotherapy has emerged as a promising treatment for metastatic triple-negative breast cancer (mTNBC), yet factors influencing its adoption remain unclear. This study examines clinical, sociodemographic, and facility-related determinants of immunotherapy use in mTNBC patients using the National Cancer Database (NCDB).

METHODS

We conducted a retrospective cohort study of mTNBC patients from the NCDB (2015-2020), categorizing them into immunotherapy recipients and non-recipients. Patients with missing data on key variables were excluded. Univariable and multivariable logistic regression identified factors influencing immunotherapy adoption. Cox proportional hazards regression and log-rank tests assessed overall survival.

RESULTS

Among 1,887 mTNBC patients, 232 (12.2%) received immunotherapy. Factors positively associated with immunotherapy use included later diagnosis year (2018-2020: OR 5.35, p < 0.001), academic facilities (OR 1.43, p = 0.044), and private insurance (OR 1.34, p < 0.001). Lower likelihood of immunotherapy use was observed in older age (71+: OR 0.49, p = 0.019), rural facilities (OR 0.43, p = 0.042), Black race (OR 0.73, p = 0.039), Hispanic ethnicity (OR 0.53, p = 0.026), and higher Charlson comorbidity scores (≥ 2: OR 0.31, p = 0.035). Immunotherapy was associated with significantly improved survival (median 2.21 vs. 1.01 years, log-rank p < 0.001) and reduced mortality risk (HR 0.59, p < 0.001).

CONCLUSION

Immunotherapy use in mTNBC has increased in recent years, with clinical, sociodemographic, and facility-related factors influencing its adoption. Our findings highlight the importance of addressing disparities in access to immunotherapy to ensure equitable treatment and better survival outcomes for all mTNBC patients.

Geographic and sociodemographic access to systemic anticancer therapies for secondary breast cancer: a systematic review

BACKGROUND

The review aimed to investigate geographic and sociodemographic factors associated with receipt of systemic anticancer therapies (SACT) for women with secondary (metastatic) breast cancer (SBC).

METHODS

Included studies reported geographic and sociodemographic factors associated with receipt of treatment with SACT for women > 18 years with an SBC diagnosis. Information sources searched were Ovid CINAHL, Ovid MEDLINE, Ovid Embase and Ovid PsychINFO. Assessment of methodological quality was undertaken using the Joanna Briggs Institute method. Findings were synthesised using a narrative synthesis approach.

RESULTS

Nineteen studies published between 2009 and 2023 were included in the review. Overall methodological quality was assessed as low to moderate. Outcomes were reported for treatment receipt and time to treatment. Overall treatment receipt ranged from 4% for immunotherapy treatment in one study to 83% for systemic anticancer therapies (unspecified). Time to treatment ranged from median 54 days to 95 days with 81% of patients who received treatment < 60 days. Younger women, women of White origin, and those women with a higher socioeconomic status had an increased likelihood of timely treatment receipt. Treatment receipt varied by geographical region, and place of care was associated with variation in timely receipt of treatment with women treated at teaching, research and private institutions being more likely to receive treatment in a timely manner.

CONCLUSIONS

Treatment receipt varied depending upon type of SACT. A number of factors were associated with treatment receipt. Barriers included older age, non-White race, lower socioeconomic status, significant comorbidities, hospital setting and geographical location. Findings should however be interpreted with caution given the limitations in overall methodological quality of included studies and significant heterogeneity in measures of exposure and outcome. Generalisability was limited due to included study populations. Findings have practical implications for the development and piloting of targeted interventions to address specific barriers in a socioculturally sensitive manner. Addressing geographical variation and place of care may require intervention at a commissioning policy level. Further qualitative research is required to understand the experience and of women and clinicians.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020196490.

Social, political, and economic determinants of access to biologics: A scoping review of structural determinants in the clinical disparities literature

BACKGROUND

The number of biologics among new medication approvals is increasing. Social, political, and economic factors influence access to these expensive medications. Disparities in access to new medications can exacerbate health disparities. The notion of "structural determinants" provides a theoretical framework for broadly evaluating the integration of upstream social, political, and economic determinants in the clinical study of access.

OBJECTIVE

To review the literature on access to FDA approved biologic medications with particular focus on the integration of social, political, and economic determinants into study design and interpretation.

METHODS

We used PRISMA guidelines to review studies on racial and socioeconomic disparities in biologic access through August 2020. We assessed whether the design or interpretation of studies considered key economic determinants of access: the biologics supply chain, trade agreements, patents, drug research and development, insurance reimbursement, and non-insurance drug policies.

RESULTS

100 studies met our inclusion criteria. Sixty-six studies considered insurance reimbursement, but trade law, patents, and other key economic determinants were rarely considered. The literature focuses on a small number of older biologics.

CONCLUSIONS

A small number of studies model the integration of structural determinants into clinical research on access to biologics, but overall this literature has many limitations and lacks integration of structural determinants. Increased interdisciplinary collaboration, availability of manufacturer data, and use of disease registries can help create structurally grounded understandings of the relationship between the political economy of expensive medications and clinical disparities.

Understanding the Implications of Medicaid Expansion for Cancer Care in the US: A Review

Importance

Insurance status has been linked to important differences in cancer treatment and outcomes in the US. With more than 15 million individuals gaining health insurance through Medicaid expansion, there is an increasing need to understand the implications of this policy within the US cancer population. This review provides an overview of the fundamental principles and nuances of Medicaid expansion, as well as the implications for cancer care.

Observations

The Patient Protection and Affordable Care Act presented states with an option to expand Medicaid coverage by broadening the eligibility criteria (eg, raising the eligible income level). During the past 10 years, Medicaid expansion has been credited with a 30% reduction in the population of uninsured individuals in the US. Such a significant change in the insurance profile could have important implications for the 1.7 million patients diagnosed with cancer each year, the oncology teams that care for them, and policy makers. However, several factors may complicate efforts to characterize the effect of Medicaid expansion on the US cancer population. Most notably, there is considerable variation among states in terms of whether Medicaid expansion took place, when expansion occurred, eligibility criteria for Medicaid, and coverage types that Medicaid provides. In addition, economic and health policy factors may be intertwined with factors associated with Medicaid expansion. Finally, variability in the manner in which cancer care has been captured and depicted in large databases could affect the interpretation of findings associated with expansion.

Conclusions and Relevance

The expansion of Medicaid was a historic public policy initiative. To fully leverage this policy to improve oncological care and to maximize learning for subsequent policies, it is critical to understand the effect of Medicaid expansion. This review aims to better prepare investigators and their audiences to fully understand the implications of this important health policy initiative.

Immune checkpoint inhibitor use, multimorbidity and healthcare expenditures among older adults with late-stage melanoma

Background: The objective of this study is to assess the impact of immune checkpoint inhibitors (ICIs) and multimorbidity on healthcare expenditures among older patients with late-stage melanoma. Materials & methods: A retrospective longitudinal cohort study using Surveillance, Epidemiology and End Results linked with Medicare claims was conducted. Generalized linear mixed models were used to analyze adjusted relationships of ICI, multimorbidity and ICI-multimorbidity interaction on average healthcare expenditures. Results: Patients who received ICI and those who had multimorbidity had significantly higher average total healthcare expenditures compared with ICI nonusers and no multimorbidity. In the fully adjusted model using ICI-multimorbidity interaction, no excess cost was added by multimorbidity. Conclusion: Use of ICIs, regardless of multimorbidity, is associated with increased healthcare expenditures.

Are there socio-economic inequalities in utilization of predictive biomarker tests and biological and precision therapies for cancer? A systematic review and meta-analysis

BACKGROUND

Novel biological and precision therapies and their associated predictive biomarker tests offer opportunities for increased tumor response, reduced adverse effects, and improved survival. This systematic review determined if there are socio-economic inequalities in utilization of predictive biomarker tests and/or biological and precision cancer therapies.

METHODS

MEDLINE, Embase, Scopus, CINAHL, Web of Science, PubMed, and PsycINFO were searched for peer-reviewed studies, published in English between January 1998 and December 2019. Observational studies reporting utilization data for predictive biomarker tests and/or cancer biological and precision therapies by a measure of socio-economic status (SES) were eligible. Data was extracted from eligible studies. A modified ISPOR checklist for retrospective database studies was used to assess study quality. Meta-analyses were undertaken using a random-effects model, with sub-group analyses by cancer site and drug class. Unadjusted odds ratios (ORs) and 95% confidence intervals (CIs) were computed for each study. Pooled utilization ORs for low versus high socio-economic groups were calculated for test and therapy receipt.

RESULTS

Among 10,722 citations screened, 62 papers (58 studies; 8 test utilization studies, 37 therapy utilization studies, 3 studies on testing and therapy, 10 studies without denominator populations or which only reported mean socio-economic status) met the inclusion criteria. Studies reported on 7 cancers, 5 predictive biomarkers tests, and 11 biological and precision therapies. Thirty-eight studies (including 1,036,125 patients) were eligible for inclusion in meta-analyses. Low socio-economic status was associated with modestly lower predictive biomarker test utilization (OR 0.86, 95% CI 0.71-1.05; 10 studies) and significantly lower biological and precision therapy utilization (OR 0.83, 95% CI 0.75-0.91; 30 studies). Associations with therapy utilization were stronger in lung cancer (OR 0.71, 95% CI 0.51-1.00; 6 studies), than breast cancer (OR 0.93, 95% CI 0.78-1.10; 8 studies). The mean study quality score was 6.9/10.

CONCLUSIONS

These novel results indicate that there are socio-economic inequalities in predictive biomarker tests and biological and precision therapy utilization. This requires further investigation to prevent differences in outcomes due to inequalities in treatment with biological and precision therapies.

Analysis of Heterogeneity in Survival Benefit of Immunotherapy in Oncology According to Patient Demographics and Performance Status: A Systematic Review and Meta-Analysis of Overall Survival Data

OBJECTIVES

Immunotherapy (IO) has become standard of care (SOC) for many advanced malignancies, although identifying patients likely to benefit remains difficult. We sought to assess whether demographic factors are associated with response to IO, compared with SOC systemic therapy, using stratified meta-analysis.

METHODS

A systematic review of MEDLINE, PubMed, Embase, and Scopus from inception to October 2, 2018. Randomized controlled trials comparing IO to SOC in patients with advanced solid organ malignancies were included if results were stratified by age, performance status (PS), or race, assessing overall survival (OS). Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for each group using random-effects models independently.

RESULTS

We identified 21 eligible randomized controlled trials, including 20 stratified by age, 17 by PS, and 4 by race. Patients with PS 0 (HR, 0.74; 95% CI, 0.63-0.86) and PS≥1 (HR, 0.75; 95% CI, 0.68-0.83) had similar OS benefits from IO compared with SOC (P=0.80). There was no difference on the basis of patient race (white vs. nonwhite) (P=0.46). IO demonstrated an OS benefit for younger (below 65 y: HR, 0.73; 95% CI, 0.65-0.82) and older (65 y and above: HR, 0.79; 95% CI, 0.71-0.88) patients with no difference between age groups (P=0.27). Among prespecified subgroup analyses, there was significant effect modification in 2 subgroups: younger patients in the first-line setting (P=0.03) and those receiving anti-CTLA-4 drugs (P=0.05).

CONCLUSIONS

When examining OS using stratified meta-analysis, we did not demonstrate significant differences in IO efficacy according to patient age, PS or race, though data on race were sparse.

The Changing Health Insurance Coverage Landscape in the United States

Changes in the health insurance coverage landscape in the United States during the past decade have important implications for receipt and affordability of cancer care. In this paper, we summarize evidence for the association between health insurance coverage and cancer prevention and treatment. We then discuss ongoing changes in health care coverage, including implementation of provisions of the Affordable Care Act, increasing prevalence of high-deductible health insurance plans, and factors that affect health care delivery, with a focus on vertical integration of hospitals and providers. We summarize the evidence for the effects of the changes in health coverage on care and discuss areas for future research with the goal of informing efforts to improve cancer care delivery and outcomes in the United States.

Insurance status impacts overall survival in Burkitt lymphoma

The impact of insurance status on clinical outcomes in Burkitt (BL) and plasmablastic (PBL) lymphomas remains unknown. We used the National Cancer Database to examine insurance status' effect on overall survival (OS) in adults diagnosed with these lymphomas between 2004 and 2014. BL patients with private insurance had significantly better OS compared to those without. In patients aged <65 years, hazard ratios were 1.4 for uninsured status (95% confidence interval 1.2-1.7), 1.2 for Medicaid (95% CI 1.0-1.4), and 1.5 for Medicare (95% CI 1.2-1.9). For patients aged >65 years, hazard ratio for uninsured status was 8.4 (95% CI 2.5-28.3). Conversely, underinsured PBL patients experienced no difference in OS. Thus, expanding insurance-related access to care may improve survival in BL, for which curative therapy exists, but not PBL, where more effective therapies are needed. Our findings add to mounting evidence that adequate health insurance is particularly important for patients with curable cancers.

Review of Colorectal Studies Using the National Cancer Database

The National Cancer Database (NCDB) is a large clinical oncology database developed with data collected from Commission on Cancer (CoC)-accredited facilities. The CoC is managed under the American College of Surgeons, and is a multidisciplinary team that maintains standards in cancer care delivery in health care settings. This database has been used in multiple cancer-focused studies and reports on cancer diagnosis, hospital-level, and patient-related demographics. The focus of this review is to explore and discuss the use of NCDB in colorectal surgery research. Furthermore, our aim for this review is to formulate a guide for researchers who are interested in using the NCDB to complete colorectal research.

Disparities in survival by insurance status in follicular lymphoma

Follicular lymphoma (FL) is the second most common non-Hodgkin lymphoma and most common indolent non-Hodgkin lymphoma. Lower socioeconomic status is associated with poor outcomes in FL, suggesting that access to care is an important prognostic factor; however, the association between insurance status and FL survival has not been sufficiently examined. The National Cancer Database, a nationwide cancer registry, was used to evaluate 43 648 patients with FL diagnosed between 2004 and 2014. All analyses were performed on 2 cohorts segmented at age 65 years to account for changes in insurance status with Medicare eligibility. Cox proportional hazard models calculated hazard ratios (HRs) with confidence intervals (CIs) for the association between insurance status and overall survival (OS) controlling for the available sociodemographic and prognostic factors. Kaplan-Meier curves display outcomes by insurance status for patients covered by private insurance, no insurance, Medicaid, or Medicare. When compared with patients younger than age 65 years with private insurance, patients younger than age 65 years with no insurance (HR, 1.96; 95% CI, 1.69-2.28), with Medicaid (HR, 1.82; 95% CI, 1.57-2.12), and with Medicare (HR, 1.96; 95% CI, 1.71-2.24) had significantly worse OS after adjusting for sociodemographic and prognostic factors. Compared with patients age 65 years or older with private insurance, those with Medicare only (HR, 1.28; 95% CI, 1.17-1.4) had significantly worse OS. For adults with FL, expanding access to care through insurance has the potential to improve outcomes.

Healthcare Utilization and Costs During the Initial Phase of Care Among Elderly Women With Breast Cancer

Background: Understanding the patterns of healthcare utilization and costs during the initial phase of care (12 months after breast cancer [BC] diagnosis) in older women (aged ≥65 years) is crucial in the allocation of Medicare resources. The objective of this study was to determine healthcare utilization and costs during the initial phase of care in older, female, Medicare fee-for-service beneficiaries diagnosed with BC, and to determine the factors associated with higher costs. Methods: A retrospective observational study using the SEER-Medicare linked database was conducted in 69,307 women aged ≥66 years diagnosed with primary incident BC in 2003-2009 to determine healthcare utilization, average costs, and costs for specific services during the initial phase of care. Generalized linear model regression was conducted to identify the factors associated with higher costs in a multivariate framework. Results: A total of 96% of women were treated with surgery during the initial phase of BC care, whereas 21% and 54% underwent chemotherapy and radiotherapy, respectively. Costs during the initial phase of care totalled $28,075 in 2012 USD, comprising $13,344 for physician services and $7,456 for outpatient services. Factors associated with higher costs during the initial phase of care were younger age (66-69 years), African American race, higher household income, advanced stages of BC, initial BC treatment, higher number of primary care physician visits, and presence of comorbidities and/or a mental condition. Conclusions: The economic burden of BC is substantial during the initial phase of care. Physician and outpatient services accounted for the highest proportion of costs. Predisposing factors, need-related factors, healthcare use, and external environmental healthcare factors significantly predicted costs during the initial phase of care.

The Influence of Individuals' Vulnerabilities and Their Interactions on the Assessment of a Primary Care Experience

This study examines the relationship between the vulnerabilities of individuals and their assessments of their primary care experiences in the setting of a universal care system. It focuses on 2 specific objectives: (1) evaluating the influence of each of the 5 vulnerabilities on the assessment of the care experience; (2) evaluating the influence of the interactions between the different types of vulnerabilities on the assessment of the care experience. The study identifies the primary care experience of 9,206 people. The health-related, biological, material, relational, and cultural vulnerabilities are also evaluated. Generally, individuals' vulnerabilities are associated with a positive assessment of the primary care experience except for the cultural vulnerability. Material vulnerability is most frequently associated with a positive assessment of the primary care experience. The interactions between the multiple vulnerabilities present for one individual often modify the effect of vulnerability on the assessment of the experience of care. The positive effect of a vulnerability on the assessment of the care experience often increases in the presence of a second vulnerability, especially the health-related vulnerability. The simultaneous presence of health-related vulnerability cancels the negative influence of cultural vulnerability on the assessment of the primary care experience.

What Predicts an Advanced-Stage Diagnosis of Breast Cancer? Sorting Out the Influence of Method of Detection, Access to Care, and Biologic Factors

BACKGROUND

Multiple studies have yielded important findings regarding the determinants of an advanced-stage diagnosis of breast cancer. We seek to advance this line of inquiry through a broadened conceptual framework and accompanying statistical modeling strategy that recognize the dual importance of access-to-care and biologic factors on stage.

METHODS

The Centers for Disease Control and Prevention-sponsored Breast and Prostate Cancer Data Quality and Patterns of Care Study yielded a seven-state, cancer registry-derived population-based sample of 9,142 women diagnosed with a first primary in situ or invasive breast cancer in 2004. The likelihood of advanced-stage cancer (American Joint Committee on Cancer IIIB, IIIC, or IV) was investigated through multivariable regression modeling, with base-case analyses using the method of instrumental variables (IV) to detect and correct for possible selection bias. The robustness of base-case findings was examined through extensive sensitivity analyses.

RESULTS

Advanced-stage disease was negatively associated with detection by mammography (P < 0.001) and with age < 50 (P < 0.001), and positively related to black race (P = 0.07), not being privately insured [Medicaid (P = 0.01), Medicare (P = 0.04), uninsured (P = 0.07)], being single (P = 0.06), body mass index > 40 (P = 0.001), a HER2 type tumor (P < 0.001), and tumor grade not well differentiated (P < 0.001). This IV model detected and adjusted for significant selection effects associated with method of detection (P = 0.02). Sensitivity analyses generally supported these base-case results.

CONCLUSIONS

Through our comprehensive modeling strategy and sensitivity analyses, we provide new estimates of the magnitude and robustness of the determinants of advanced-stage breast cancer.

IMPACT

Statistical approaches frequently used to address observational data biases in treatment-outcome studies can be applied similarly in analyses of the determinants of stage at diagnosis. Cancer Epidemiol Biomarkers Prev; 25(4); 613-23. ©2016 AACR.

Insurance status is related to diffuse large B-cell lymphoma survival

BACKGROUND

Insurance status is associated with stage at diagnosis and treatment for non-Hodgkin lymphoma (NHL), but no previous studies have addressed the relation between insurance status and survival for patients diagnosed with diffuse large B-cell lymphoma (DLBCL), the most common subtype of NHL.

METHODS

The authors analyzed survival among 3858 patients with DLBCL ages 18 to 64 years who were diagnosed in 2004 using data from the National Cancer Database, a nationwide, hospital-based cancer registry. Kaplan-Maier curves were compared between patients who had private insurance, Medicaid, and no insurance. Cox proportional hazards models were fitted to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for insurance controlling for age, sex, race, area-level socioeconomic status, and potential mediators of the association between insurance status and survival, including stage at diagnosis, B-symptoms, comorbidity, and treatment.

RESULTS

After adjusting for sociodemographic factors, uninsured patients (HR, 1.39; 95% CI, 1.14-1.70) and Medicaid-insured patients (HR, 1.48; 95% CI, 1.23-1.78) with DLBCL had lower survival compared with patients who had private insurance. This association was attenuated after adjusting for the potential mediators (for uninsured patients, HR, 1.18 [95% CI, 0.96-1.44]; for Medicaid-insured patients, HR, 1.27 [95% CI, 1.06-1.53]).

CONCLUSIONS

Uninsured and Medicaid-insured patients with DLBCL had inferior survival compared with privately insured patients. These associations can be explained in part because uninsured/Medicaid-insured patients who have DLBCL present with more advanced-stage disease and comorbid illnesses and less commonly receive standard treatment. Access to affordable and adequate health care has the potential to improve survival for patients with DLBCL.

Socioeconomic inequality in the use of rituximab therapy among non-Hodgkin lymphoma patients in Chinese public hospitals

Rituximab is a patient-paid effective monoclonal-antibody drug for non-Hodgkin lymphoma (NHL). Little is known in China, a country with unequal distribution of wealth and medical insurance systems, about the impact of socioeconomic status (SES) on selecting rituximab therapy in NHL patients. A total of 328 NHL inpatients in 2 public hospitals in Hangzhou were recruited and divided into 2 equal groups: with rituximab therapy and with no rituximab therapy group. Selection and frequency of rituximab therapy increased with duration of education and in urban citizens (P < .01). Officers and businessmen were more likely to use rituximab therapy compared with farmers (P < .01). Patients covered by Urban Employee Basic Medical Insurance were more likely to select rituximab therapy than those insured with Urban-Rural Residents Basic Medical Insurance (P < .01). There was an inequality in provision of rituximab therapy among Chinese NHL patients, and this was associated with differences in SES status. Effective measures are suggested to ameliorate the inequality issue.

Impact of insurance status on access to care and out-of-pocket costs for U.S. individuals with epilepsy

We analyzed data from the 2002-2007 Medical Expenditure Panel Survey (MEPS) to assess whether individuals with epilepsy who are uninsured and those who have Medicaid coverage experience differences in medical resource utilization or out-of-pocket costs compared with those having other types of insurance. With sociodemographic characteristics controlled for, uninsured individuals had significantly fewer outpatient visits, fewer visits with neurologists, and greater antiepileptic drug costs than did those with private insurance. Individuals with Medicaid coverage had similar medical resource utilization rates but lower out-of-pocket costs compared with privately insured individuals. These findings indicate substantial barriers to receipt of appropriate medical care for uninsured individuals with epilepsy, but not for those with Medicaid coverage. Future studies should evaluate whether ongoing changes to the US health care system are able to address the differences in care we found among uninsured individuals with epilepsy and should incorporate measures of disease severity and unmet need.

Pattern of hypomethylating agents use among elderly patients with myelodysplastic syndromes

Little is known about how hypomethylating agents (HMAs) have been adopted into the treatment of myelodysplastic syndromes (MDS). We conducted a population-based study to assess the use of HMAs among 4416 MDS patients (age≥66 years) who were diagnosed during 2001-2005 and followed up through the end of 2007. Multivariate logistic regression models were utilized to evaluate the role of various patient characteristics. 475 (10.8%) patients had received HMAs by 2007, with the proportion increasing over time. Patients who were white (odds ratio (OR)=0.66, 95% confidence interval (CI): 0.46-0.95), male (OR=1.47, 95% CI: 1.19-1.82), young (Ptrend<0.01), more recently diagnosed (OR=1.90, 95% CI: 1.54-2.34), had fewer comorbidities (Ptrend<0.01), or had a history of other cancer (OR=1.28, 95% CI: 1.00-1.63) were more likely to receive HMAs. Compared with patients with refractory anemia, those diagnosed with refractory anemia with excess blasts or refractory cytopenia with multilineage dysplasia had a higher chance to be treated with HMAs (OR=3.52 and 2.32, respectively). Relatively few MDS patients were treated with HMAs during the introduction period of these agents, and multiple patient characteristics such as sex, comorbidities, and MDS subtype influence the likelihood a patient receives HMAs.

Brachytherapy for Accelerated Partial-Breast Irradiation: A Rapidly Emerging Technology in Breast Cancer Care

Purpose

Brachytherapy is a method for delivering partial-breast irradiation after breast-conserving surgery (BCS). It is currently used in the community setting, although its efficacy has yet to be validated in prospective comparative trials. Frequency and factors influencing use have not been previously identified.

Methods

In a nationwide database of 6,882 Medicare beneficiaries (age ≥ 65 years) with private supplemental insurance (MarketScan Medicare Supplemental), claims codes identified patients treated with brachytherapy versus external-beam radiation after BCS for incident breast cancer (diagnosed from 2001 to 2006). Logistic regression modeled predictors of brachytherapy use.

Results

Frequency of brachytherapy use as an alternative to external-beam radiation after BCS increased over time (< 1% in 2001, 2% in 2002, 3% in 2003, 5% in 2004, 8% in 2005, 10% in 2006; P < .001). Increased use correlated temporally with US Food and Drug Administration approval and Medicare reimbursement of brachytherapy technology. Brachytherapy use was more likely in women with lymph node–negative disease (odds ratio [OR], 2.19; 95% CI, 1.17 to 4.11) or axillary surgery (OR, 1.74; 95% CI, 1.23 to 2.44). Brachytherapy use was also more likely in women with non–health maintenance organization insurance (OR, 1.81; 95% CI, 1.24 to 2.64) and in areas with higher median income (OR, 1.58; 95% CI, 1.05 to 2.38), lower density of radiation oncologists (OR, 1.78; 95% CI, 1.11 to 2.86), or higher density of surgeons (OR, 1.57; 95% CI, 1.07 to 2.31).

Conclusion

Despite ongoing questions regarding efficacy, breast brachytherapy was rapidly incorporated into the care of older, insured patients. In our era of frequently emerging novel technologies yet growing demands to optimize costs and outcomes, results provide insight into how clinical, policy, and socioeconomic factors influence new technology diffusion into conventional care.