Adoption of Gene Expression Profiling for Breast Cancer in US Oncology Practice for Women Younger Than 65 Years

Hospital Rurality and Gene Expression Profiling for Early-Stage Breast Cancer among Iowa Residents (2010-2018)

Objective

Given the challenges rural cancer patients face in accessing cancer care as well as the slower diffusion and adoption of new medical technologies among rural providers, the aim of our study was to examine trends in gene expression profiling (GEP) testing and evaluate the association between hospital rurality and receipt of GEP testing.

Methods

Data from the Iowa Cancer Registry (ICR) were used to identify women with newly diagnosed, histologically confirmed breast cancer from 2010 through 2018 who met eligibility criteria for GEP testing. Patients were allocated to the hospitals where their most definitive surgical treatment was received, and Rural-Urban Commuting Area codes were used to categorize hospitals into urban (N = 43), large rural (N = 16), and small rural (N = 48). Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression to evaluate the association between hospital rurality and GEP test use, adjusting for demographic and clinical characteristics. The association between test result and treatment received was assessed among patients who received Oncotype DX (ODX) testing.

Results

Of 6,726 patients eligible for GEP test use, 46% (N = 3,069) underwent testing with 95% receiving ODX. While overall GEP testing rates increased over time from 42% between 2010 and 2012 to 51% between 2016 and 2018 (P _trend < 0.0001), use continued to be the lowest among patients treated at hospitals in small rural areas. The odds of GEP testing remained significantly lower among patients treated at hospitals located in small rural areas (aOR 0.55; 95% CI 0.43-0.71), after adjusting for demographic and clinical characteristics. ODX recurrence scores were highly correlated with chemotherapy use across all strata of hospital rurality.

Conclusions

GEP testing continues to be underutilized, especially among those treated at small rural hospitals. Targeted interventions aimed at increasing rates of GEP testing to ensure the appropriate use of adjuvant chemotherapy may improve health outcomes and lower treatment-related costs.

Analyzing Precision Medicine Utilization with Real-World Data: A Scoping Review

Precision medicine (PM), specifically genetic-based testing, is currently used in over 140,000 individual tests to inform the clinical management of disease. Though several databases (e.g., the NIH Genetic Testing Registry) demonstrate the availability of these sequencing-based tests, we do not currently understand the extent to which these tests are used. There exists a need to synthesize the body of real-world data (RWD) describing the use of sequencing-based tests to inform their appropriate use. To accomplish this, we performed a scoping review to examine what RWD sources have been used in studies of PM utilization between January 2015 and August 2021 to characterize the use of genome sequencing (GS), exome sequencing (ES), tumor sequencing (TS), next-generation sequencing-based panels (NGS), gene expression profiling (GEP), and pharmacogenomics (PGx) panels. We abstracted variables describing the use of these types of tests and performed a descriptive statistical analysis. We identified 440 articles in our search and included 72 articles in our study. Publications based on registry databases were the most common, followed by studies based on private insurer administrative claims. Slightly more than one-third (38%) used integrated datasets. Two thirds (67%) of the studies focused on the use of tests for oncological clinical applications. We summarize the RWD sources used in peer-reviewed literature on the use of PM. Our findings will help improve future study design by encouraging the use of centralized databases and registries to track the implementation and use of PM.

Out-of-pocket and private pay in clinical genetic testing: A scoping review

Full coverage of the cost of clinical genetic testing is not always available through public or private insurance programs, or a public healthcare system. Consequently, some patients may be faced with the decision of whether to finance testing out-of-pocket (OOP), meet OOP expenses required by their insurer, or not proceed with testing. A scoping review was conducted to identify literature associated with patient OOP and private pay in clinical genetic testing. Seven databases (EMBASE, MEDLINE, CINAHL, PsychINFO, PAIS, the Cochrane Database of Systematic Reviews, and the JBI Evidence-Based Practice database) were searched, resulting in 83 unique publications included in the review. The presented evidence includes a descriptive analysis, followed by a narrative account of the extracted data. Results were divided into four groups according to clinical indication: (1) hereditary breast and ovarian cancer, (2) other hereditary cancers, (3) prenatal testing, (4) other clinical indications. The majority of studies focused on hereditary cancer and prenatal genetic testing. Overall trends indicated that OOP costs have fallen and payer coverage has improved, but OOP expenses continue to present a barrier to patients who do not qualify for full coverage.

Assessment of hormonal levels as prognostic markers and of their optimal cut-offs in small intestinal neuroendocrine tumours grade 2

PURPOSE

Small intestinal neuroendocrine tumours (siNETs) with a Ki-67 proliferation index between 3 and 20% belong to WHO grade 2. Response to treatment may be monitored by blood chromogranin A (CgA) and urine 5-hydroxyindoleacetic acid (5HIAA). The aim of this retrospective study was to investigate the prognostic value of baseline CgA and 5HIAA and of the early biochemical response to treatment, and to compare different cut-off values used in the literature.

METHODS

A retrospective cohort study of 184 patients with siNET Grade 2 treated with somatostatin analogues (SSA), interferon-alpha (IFN) or peptide receptor radionuclide therapy (PRRT).

RESULTS

Baseline CgA was a statistically significant prognostic marker for both cancer-specific survival (CSS) and progression-free survival (PFS). A cut-off of 5 × ULN (upper limit of normal) was best discriminative in most cases, but 2 × ULN discriminated better for SSA. Baseline 5HIAA was a prognostic marker for CSS in treatment with IFN and PRRT, but not for single SSA. Early changes of CgA and 5HIAA correlated well with CSS (HR 3.18, 95% CI 1.82-5.56 and HR 1.47, 95% CI 1.16-1.86) and PFS (HR 3.08, 95% CI 1.86-5.10 and HR 1.37, 95% CI 1.11-1.68) for SSA, but not for PRRT.

CONCLUSIONS

Baseline CgA and to a lesser extent 5HIAA are associated with CSS irrespective of treatment used, and with PFS after PRRT, and 5 × ULN provides best discrimination in many, but not all, cases. Early reductions of CgA and 5HIAA are prognostic for treatment with SSA, but not PRRT.

Characterizing patient-oncologist communication in genomic tumor testing: The 21-gene recurrence score as an exemplar

OBJECTIVE

Women with early-stage, ER + breast cancer are recommend to receive genomic profiling tests, such as the 21-gene Recurrence Score (RS) test, to guide treatment decisions. We examined test- and treatment-related information discussed and the associations between RS categories and aspects of communication during patient-oncologist clinical encounters.

METHODS

As part of a larger trial, clinical encounters (N = 46) were audiorecorded and coded for 1) RS- and treatment-related information, 2) shared decision making, 3) patient active participation, and 4) oncologist patient-centered communication. We examined differences by RS category using mixed models, adjusting for nesting within oncologist.

RESULTS

Patients with a high RS were more likely to receive a chemotherapy recommendation (p < .01), hear about the risks/side effects of chemotherapy (p < .01), and offer their preferences (p = .02) than those with intermediate or low RS. Elements of shared decision making increased with RS. Oncologist patient-centered communication (M = 4.09/5, SD = .25) and patient active participation (M = 3.5/4, SD = 1.0) were high across RS.

CONCLUSION

Findings suggest that disease severity, rather than clinical uncertainty, impact treatment recommendations and shared decision making.

PRACTICE IMPLICATIONS

Oncologists adjust test- and treatment-related information and shared decision making by disease severity. This information provides a framework to inform decision making in complex cancer and genomics settings.

Question Prompt List to Support Patient-Provider Communication in the Use of the 21-Gene Recurrence Test: Feasibility, Acceptability, and Outcomes

PURPOSE

The 21-gene recurrence score (RS) assay is used to guide breast cancer treatment decisions but can be poorly understood by patients. We examined the effects of a question prompt list (QPL) on knowledge, distress, and decisional conflict related to genomic testing and treatment in early-stage breast cancer.

METHODS

We describe the feasibility and acceptability of the QPL and the impact of the QPL on knowledge, distress, and decisional conflict before and after the receipt of the QPL (MEND 2, N = 65). We also compared distress and decisional conflict between women who received the QPL (MEND 2, N = 65) and a comparable group of women who did not receive the QPL who participated in an earlier observational study within the same clinics (MEND 1, N = 136).

RESULTS

MEND 2 participants indicated high acceptability and feasibility using the QPL. Knowledge increased post-QPL (P < .01) but did not decrease distress. Decisional conflict was lower among women in MEND 2 compared with those in MEND 1 (P < .01), with no statistically significant differences in distress.

CONCLUSION

The findings suggest that the QPL is feasible, acceptable, can improve knowledge and decrease decisional conflict in the large group of women deciding treatment while integrating RS test results.

Trends in the Use of Cardiac Imaging for Women with Newly Diagnosed Breast Cancer

We investigated time trends and factors associated with the use of cardiac imaging among women with early-stage breast cancer prior to the initiation of treatment. Of 11,732 women ages 24-64, diagnosed with stage I-III breast cancer in 2006-2011, 2550 (22%) received anthracycline-based chemotherapy. Baseline cardiac imaging was used in 79% of patients receiving anthracyclines and increased over time. Of 2277 (20%) women who received non-anthracycline therapy, 16% received cardiac imaging. Women receiving cardiac imaging in non-anthracycline therapy group were more likely to have higher cardiovascular risk, as well as higher cancer stage and worse histological tumor grade suggesting that results of imaging might have influenced the choice of cancer therapy. Our findings indicate the need for cardio-oncology collaboration in identification and treatment of women at high risk for adverse oncology and cardiovascular outcomes.

Combined Detection of HER2, Ki67, and GSTP1 Genes on the Diagnosis and Prognosis of Breast Cancer

OBJECTIVE

Breast cancer (BC) is a common malignant tumor in females. The combined assay of multiple molecular markers benefits the diagnosis and prognostic prediction. Human epidermal growth factor receptor 2 (HER2) facilitates the proliferation and differentiation of cancer cells through ligand binding. Ki67 is a tumor proliferation-related gene, whereas GSTP1 is a DNA repair-related gene. This study thus investigated the significance of HER2 and Ki67/GSTP1 gene combined assay in the diagnosis and prognosis of BC.

MATERIALS AND METHODS

A total of 86 breast tumor tissues and adjacent tissues were collected. Gene expression and protein levels of HER2 and Ki67 were quantified by real-time polymerase chain reaction (PCR) and Western blot, respectively. Methylation frequency of GSTP1 was analyzed by methylation-specific PCR. The correlation between HER2 and Ki67/GSTP1 and clinical/pathological features of BC was analyzed.

RESULTS

Gene and protein expression levels of HER2 and Ki67 in tumor tissues were increased (p < 0.05 compared with adjacent tissues). Methylation frequency of GSTP1 gene was 37.2%, which was significantly higher in breast tumor tissues than in adjacent tissues (12.79%, p < 0.05). HER2 expression was positively correlated with TNM stage, tumor size, and lymph node metastasis, and negatively correlated with tissue grade and estrogen receptor (ER)/progesterone receptor (PR) expression (p < 0.05). GSTP1 methylation was positively correlated with TNM stage and tumor size, and negatively correlated with ER/PR expression (p < 0.05).

CONCLUSIONS

HER2, Ki67, and GSTP1 methylation were correlated with clinical and pathological features of BC. The combined assay benefits the early diagnosis and prognostic prediction of cancer.

The impact of gene expression profile testing on confidence in chemotherapy decisions and prognostic expectations

PURPOSE

Little is known about whether gene expression profile (GEP) testing and specific recurrence scores (e.g., medium risk) improve women's confidence in their chemotherapy decision or perceived recurrence risk. We evaluate the relationship between these outcomes and GEP testing.

METHODS

We surveyed women eligible for GEP testing (stage I or II, Gr1-2, ER+, HER2-) identified through the Surveillance, Epidemiology, and End Results (SEER) Registry of Washington or Kaiser Permanente Northern California from 2012 to 2016, approximately 0-4 years from diagnosis (N = 904, RR = 45.4%). Confidence in chemotherapy was measured as confident (Very, completely) versus Not Confident (Somewhat, A little, Not At All); perceived risk recurrence was recorded numerically (0-100%). Women reported their GEP test receipt (Yes, No, Unknown) and risk recurrence score (High, Intermediate, Low, Unknown). In our analytic sample (N = 833), we propensity score weighted the three test receipt cohorts and used propensity weighted multivariable regressions to examine associations between the outcomes and the three test receipt cohorts, with receipt stratified by score.

RESULTS

29.5% reported an unknown GEP test receipt; 86% being confident. Compared to no test receipt, an intermediate score (aOR 0.34; 95% CI 0.20-0.58), unknown score (aOR 0.09; 95% CI 0.05-0.18), and unknown test receipt (aOR 0.37; 95% CI 0.24-0.57) were less likely to report confidence. Most women greatly overestimated their recurrence risk regardless of their test receipt or score.

CONCLUSIONS

GEP testing was not associated with greater confidence in chemotherapy decisions. Better communication about GEP testing and the implications for recurrence risk may improve women's decisional confidence.

Multilevel Influences on Patient-Oncologist Communication about Genomic Test Results: Oncologist Perspectives

Thousands of women with early-stage breast cancer receive gene-expression profile (GEP) tests to guide chemotherapy decisions. However, many patients report a poor understanding of how their test results inform treatment decision-making. We applied models of patient-centered communication and informed decision-making to assess which variables oncologists' perceive as most influential to effective communication with their patients about GEP results and intervention modalities and approaches that could support more effective conversations about treatment decisions in routine clinical care. Medical oncologists who were part of a practice group in the mid-Atlantic US completed an online, cross-sectional survey in 2016. These data were merged with de-identified electronic patient and practice data. Of the 83 oncologists contacted, 29 completed the survey (35% response rate, representing 52% of the test-eligible patients in the practice network). There were no significant differences between survey responders and nonresponders. Oncologists reported patient-related variables as most influential, including performance status (65.5%), pretesting preferences for chemotherapy (55.2%), and comprehension of complex test results (55.2%). Oncologists endorsed their experience with testing (58.6%) and their own confidence in using the test results (48.3%) as influential as well. They indicated that a clinical decision support tool incorporating patient comorbidities, age, and potential benefits from chemotherapy would support their own practice and that they could share these results and other means of communication support using print materials (79.3%) with their patients in clinic (72.4%). These preferred intervention characteristics could be integrated into routine care, ultimately facilitating more effective communication about genomic testing (such as GEP) and its role in treatment selection.

Uptake of BRCA 1/2 and oncotype DX testing by medical and surgical oncologists

PURPOSE

The diffusion of genomic testing is critical to the success of precision medicine, but there is limited information on oncologists' uptake of genetic technology. We aimed to assess the frequency with which medical oncologists and surgeons order BRCA 1/2 and Oncotype DX testing for breast cancer patients.

METHODS

We surveyed 732 oncologists and surgeons treating breast cancer patients. Physicians were from Florida, New York, New Jersey, and Pennsylvania, and were listed in the 2010 AMA Masterfile or identified by patients.

RESULTS

80.6% of providers ordered BRCA 1/2 testing at least sometimes and 85.4% ordered Oncotype DX (p = 0.01). More frequent ordering of BRCA 1/2 was associated with more positive attitudes toward genetic innovation (OR 1.14, p = 0.001), a belief that testing was likely to be covered by patients' insurance (OR 2.84, p < 0.001), and more frequent ordering of Oncotype DX testing (OR 8.69, p < 0.001). More frequent use of Oncotype DX was associated with a belief that testing was likely to be covered by insurance (OR 7.33, p < 0.001), as well as with more frequent ordering of BRCA 1/2 testing (OR 9.48, p < 0.001).

CONCLUSIONS

Nearly one in five providers never or rarely ever ordered BRCA 1/2 testing for their breast cancer patients, and nearly 15% never or rarely ever ordered Oncotype DX. Less frequent ordering of BRCA 1/2 is associated with less frequent use of Oncotype DX testing, and vice versa. Those who do not order BRCA 1/2 testing report less positive attitudes toward genetic innovation. Further education of this subset of providers regarding the benefits of precision medicine may enable more rapid diffusion of genetic technology.

Cost Effectiveness of Gene Expression Profile Testing in Community Practice

Purpose Gene expression profile (GEP) testing can support chemotherapy decision making for patients with early-stage, estrogen receptor-positive, human epidermal growth factor 2-negative breast cancers. This study evaluated the cost effectiveness of one GEP test, Onco type DX (Genomic Health, Redwood City, CA), in community practice with test-eligible patients age 40 to 79 years. Methods A simulation model compared 25-year societal incremental costs and quality-adjusted life-years (QALYs) of community Onco type DX use from 2005 to 2012 versus usual care in the pretesting era (2000 to 2004). Inputs included Onco type DX and chemotherapy data from an integrated health care system and national and published data on Onco type DX accuracy, chemotherapy effectiveness, utilities, survival and recurrence, and Medicare and patient costs. Sensitivity analyses varied individual parameters; results were also estimated for ideal conditions (ie, 100% testing and adherence to test-suggested treatment, perfect test accuracy, considering test effects on reassurance or worry, and lowest costs). Results Twenty-four percent of test-eligible patients had Onco type DX testing. Testing was higher in younger patients and patients with stage I disease ( v stage IIA), and 75.3% and 10.2% of patients with high and low recurrence risk scores received chemotherapy, respectively. The cost-effectiveness ratio for testing ( v usual care) was $188,125 per QALY. Considering test effects on worry versus reassurance decreased the cost-effectiveness ratio to $58,431 per QALY. With perfect test accuracy, the cost-effectiveness ratio was $28,947 per QALY, and under ideal conditions, it was $39,496 per QALY. Conclusion GEP testing is likely to have a high cost-effectiveness ratio on the basis of community practice patterns. However, realistic variations in assumptions about key variables could result in GEP testing having cost-effectiveness ratios in the range of other accepted interventions. The differences in cost-effectiveness ratios on the basis of community versus ideal conditions underscore the importance of considering real-world implementation when assessing the new technology.

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.

Endocrine therapy initiation, discontinuation and adherence and breast imaging among 21-gene recurrence score assay-eligible women under age 65

BACKGROUND

Aside from chemotherapy utilization, limited data are available on the relationship between gene expression profiling (GEP) testing and breast cancer care. We assessed the relationship between GEP testing and additional variables and the outcomes of endocrine therapy initiation, discontinuation and adherence, and breast imaging exams in women under age 65 years.

METHODS

Data from five state cancer registries were linked with claims data and GEP results. We assessed variables associated with survivorship care outcomes in an incident cohort of 5014 commercially insured women under age 65 years, newly diagnosed with stage I or II hormone-receptor-positive, human epidermal growth factor receptor 2 (HER2) non-positive breast cancer from 2006 to 2010.

RESULTS

Among tested women, those with high Oncotype DX® Breast Recurrence Score® (RS) were significantly less likely to initiate endocrine therapy than women with low RS tumors (OR 0.40 (95% CI 0.20 to 0.81); P = 0.01). Among all test-eligible women, receipt of Oncotype DX testing was associated with a greater likelihood of endocrine therapy initiation (OR 2.48 (95% CI 2.03 to 3.04); P <0.0001). The odds of initiation were also significantly higher for tested vs. untested women among women who did not initiate chemotherapy within six months of diagnosis (OR 3.25 (95% CI 2.53 to 4.16)), with no effect in women who received chemotherapy. Discontinuation and adherence and breast imaging exams were unrelated to tested status or RS.

CONCLUSIONS

Lower endocrine therapy initiation rates among women with high RS tumors and among untested women not receiving chemotherapy are concerning, given its established efficacy. Additional research is needed to suggest mechanisms to close this gap.

Impact of genomic testing and patient-reported outcomes on receipt of adjuvant chemotherapy

Practice guidelines incorporate genomic tumor profiling, using results such as the Oncotype DX Recurrence Score (RS), to refine recurrence risk estimates for the large proportion of breast cancer patients with early-stage, estrogen receptor-positive disease. We sought to understand the impact of receiving genomic recurrence risk estimates on breast cancer patients' well-being and the impact of these patient-reported outcomes on receipt of adjuvant chemotherapy. Participants were 193 women (mean age 57) newly diagnosed with early-stage breast cancer. Women were interviewed before and 2-3 weeks after receiving the RS result between 2011 and 2015. We assessed subsequent receipt of chemotherapy from chart review. After receiving their RS, perceived pros (t = 4.27, P < .001) and cons (t = 8.54, P < .001) of chemotherapy increased from pre-test to post-test, while perceived risk of breast cancer recurrence decreased (t = 2.90, P = .004). Women with high RS tumors were more likely to receive chemotherapy than women with low RS tumors (88 vs. 5 %, OR 0.01, 0.00-0.02, P < .001). Higher distress (OR 2.19, 95 % CI 1.05-4.57, P < .05) and lower perceived cons of chemotherapy (OR 0.50, 95 % CI 0.26-0.97, P < .05) also predicted receipt of chemotherapy. Distressed patients who saw few downsides of chemotherapy received this treatment. Clinicians should consider these factors when discussing chemotherapy with breast cancer patients.