Review of testing and use of adjuvant trastuzumab across a cancer network--are we treating the right patients?

Assessment of CPS + EG, Neo-Bioscore and Modified Neo-Bioscore in Breast Cancer Patients Treated With Preoperative Systemic Therapy: A Multicenter Cohort Study

This study was to assess the prognosis stratification of the clinical-pathologic staging system incorporating estrogen receptor (ER)-negative disease, the nuclear grade 3 tumor pathology (CPS + EG), Neo-Bioscore, and a modified Neo-Bioscore system in breast cancer patients after preoperative systemic therapy (PST). A retrospective multicenter cohort study was conducted from 12 participating hospitals' databases from 2006 to 2015. Five-year disease free survival (DFS), disease specific survival (DSS), and overall survival (OS) were calculated using Kaplan-Meier Method. Area under the curve (AUC) of the three staging systems was compared. Wald test and maximum likelihood estimates in Cox proportional hazards model were used for multivariate analysis. A total of 1,077 patients were enrolled. The CPS + EG, Neo-Bioscore, and modified Neo-Bioscore could all stratify the DFS, DSS, and OS (all P < 0.001). While in the same stratum of Neo-Bioscore scores 2 and 3, the HER2-positive patients without trastuzumab therapy had much poorer DSS (P = 0.013 and P values < 0.01, respectively) as compared to HER2-positive patients with trastuzumab therapy and HER2-negative patients. Only the modified Neo-Bioscore had a significantly higher stratification of 5-year DSS than PS (AUC 0.79 vs. 0.65, P = 0.03). So, the modified Neo-Bioscore could circumvent the limitation of CPS + EG or Neo-Bioscore.

Clinical Trial Registration

ClinicalTrials.gov, identifier NCT03437837.

The use of trastuzumab affected by health insurance policy in Jiangsu Province of China

BACKGROUND

Breast cancer recurrence and mortality have been shown to decrease after trastuzumab treatment in human epidermal growth factor 2 (HER2)-positive early-stage breast cancer (EBC) patients. In Jiangsu Province, trastuzumab has been subsidized for patients with HER2-positive EBC since 2013. Several studies showed that Jiangsu was one of the provinces with the highest rates of adjuvant trastuzumab therapy. To uncover the underlying reason, we designed the study to investigate trastuzumab use for HER2-positive breast cancer patients, and to examine the changes caused by medical insurance coverage for trastuzumab in Jiangsu province of China.

METHODS

This was a retrospective, multicenter clinical study with follow-up data. HER2-positive EBC patients diagnosed in 7 representative hospitals in 2010, 2011, and 2013 were enrolled. Demographic and clinical data, and details of diagnosis, treatments, and prognosis, were collected. Data analysis included univariate analysis, multivariate logistic regression, survival analysis, and subgroup analysis.

RESULTS

Of the 641 patients (mean age 51.01±10.79 years) included, 412 (64.27%) patients had medical insurance. Trastuzumab therapy was given to 214 (33.39%) patients. The multivariate logistic regression showed that medical insurance coverage, age, and radiotherapy were associated with trastuzumab use (P<0.05). The overall survival was significantly better in the trastuzumab group than in the non-trastuzumab group (HR: 1.607; 95% CI: 1.046-2.469; P=0.040). Subgroup analysis revealed that there was a trend towards more patients with medical insurance (P=0.073), and significantly more patients received trastuzumab therapy (P<0.001) in 2013 than in 2010-2011. Additionally, trastuzumab use in China was lower than in developed countries. Patients with medical insurance were more likely to use trastuzumab, and more patients could afford trastuzumab therapy with the development of China's health-care reform.

CONCLUSIONS

Our study suggested that the percentage of patients who received trastuzumab in China was lower than developed countries. Patients who had medical insurance were more likely to use trastuzumab than those without medical insurance. The health insurance policy in China has improved access for breast cancer patients who require trastuzumab therapy.

Adherence to human epidermal growth factor receptor-2 testing and adjuvant trastuzumab treatment guidelines in Ontario

OBJECTIVES

We evaluated adherence of human epidermal growth factor receptor-2 testing using immunohistochemistry and fluorescence in situ hybridization, as well as adjuvant trastuzumab treatment according to Canadian guidelines, and predictors of trastuzumab use in early-stage breast cancer in Ontario.

METHODS

Retrospective cohort of early-stage breast cancer patients identified in the Ontario Cancer Registry. Human epidermal growth factor receptor-2 test type, sequence, result(s), tumor grade, and hormone receptor status were abstracted from Ontario Cancer Registry pathology reports. Trastuzumab treatment was determined from provincial cancer agency records. Other variables were determined from administrative data sources. Logistic regression models were used to estimate adjusted odds ratios for factors associated with guideline adherence.

RESULTS

The first human epidermal growth factor receptor-2 test result was the strongest predictor of confirmatory testing (p < 0.05). Human epidermal growth factor receptor-2 testing by immunohistochemistry accounted for the majority of documented first tests (94%; n = 8249). Overall, 27% (n = 2360) of tested patients received a second test by fluorescence in situ hybridization (46%) or immunohistochemistry (49%) assay. Most human epidermal growth factor receptor-2 equivocal patients (89%; n = 784) received a confirmatory test. Among human epidermal growth factor receptor-2-positive patients, only 57% (n = 385) received trastuzumab treatment within the study period. Human epidermal growth factor receptor-2 status was the strongest predictor of trastuzumab use. Younger patients (<70 years at diagnosis) and negative hormone receptor status had higher odds of trastuzumab treatment (p < 0.05) compared to older and positive hormone receptor status patients.

CONCLUSIONS

Immunohistochemistry use as a first test was largely consistent with Canadian guidelines; however, immunohistochemistry was frequently used as a confirmatory test, which is not guideline-concordant. Monitoring these testing and treating patterns is necessary to optimize health outcomes associated with trastuzumab.

Trastuzumab uptake in HER2-positive breast cancer patients: a systematic review and meta-analysis of observational studies

Overexpression of the HER2 gene is predictive of treatment benefit with trastuzumab therapy for breast cancer (BC) patients. The study objective was to investigate whether all eligible patients with HER2-positive BC initiated trastuzumab therapy. A systematic search was conducted through PubMed, Web of Science PsycINFO, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Cochrane Library. From 2651 studies identified, 107 observational studies were included for full text review, of which 26 met the inclusion criteria and an additional 7 studies were identified through citation searching. Two independent reviewers extracted data for accuracy and completeness. From 33 observational studies, 14,644 patients were exposed to trastuzumab therapy. Age range varied across studies; the youngest cohort had a median age of 50 and the oldest had a median age of 84. Sample sizes ranged from 11 to 1928 and included patients from 10 countries. Studies were heterogenous and few studies accounted for confounders. We identified large variability in uptake of trastuzumab in HER2-positive early BC patients (9.1-100%) and metastatic BC patients (50.8-84.0%). The pooled uptake was 71.3% (95% CI 64.6-77.9%), with high heterogeneity (I² = 99.05%). The most conservative predictors of higher uptake included younger age (OR 2.09; 95% CI 1.36-3.20) and lower Charlson Comorbidity Index of patients (OR 1.62; 95% CI 1.32-1.99). In addition, tumour characteristics including higher tumour grade (OR 1.73; 95% CI 1.23-2.45), larger tumour size (OR 1.80; 95% CI 1.54-2.10), advanced tumour stage (OR 2.07; 95% CI 1.44-2.96) and hormone receptor negative tumor (OR 1.54; 95% CI 1.35-1.77) were associated with higher uptake. The uptake of trastuzumab therapy varied widely between studies and across subgroups suggesting that there may be some inequalities in the use of this agent. However, our findings should be interpreted with caution due to study heterogeneity and potential confounding, and thus additional studies of individual level data which control for confounders are needed to understand more about inequalities in uptake.

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.

Guideline Adherence Regarding the Use of Expensive Drugs in Daily Practice: The Examples of Trastuzumab in Breast Cancer and Bortezomib in Multiple Myeloma

BACKGROUND

The present study was designed to obtain insights into guideline adherence regarding the use of expensive drugs in The Netherlands in daily practice and into the patients' perspective on the decision-making process.

MATERIAL AND METHODS

A retrospective review of medical charts regarding the use of trastuzumab in early and metastatic breast cancer (EBC/MBC) and bortezomib in multiple myeloma (MM) was conducted. Prescription according to clinical practice guidelines was assessed. The review was supplemented with patient interviews.

RESULTS

Of 702 adjuvant-treated EBC patients, 97% had a documented human epidermal growth factor receptor 2 (HER2) testing (23% HER2 positive). 92% (147/160) of the HER2-positive EBC patients were treated with trastuzumab. Of 594 MBC patients, 81% had a documented HER2 testing (19% HER2 positive). 82% (75/91) of the HER2-positive MBC patients were treated with trastuzumab. Of 68 MM patients, 50% were treated with bortezomib. Reasons not to treat were consistent with the guidelines. Patients were generally satisfied with the decision-making process; improvements in patient education were suggested (e.g., repeating the information given, adding information on side effects).

CONCLUSIONS

Guidelines were generally well followed with respect to trastuzumab and bortezomib, indicating that funding did not influence the treatment decisions of physicians. In view of the growing numbers of both cancer patients and expensive new anticancer drugs, and increasing budget constraints, it is unclear whether the present-day policies will guarantee a similar level of guideline adherence. Patient involvement in decision-making could be increased by improving the patient education on treatment.

Non-initiation and early discontinuation of adjuvant trastuzumab in women with localized HER2-positive breast cancer

One year of trastuzumab therapy is recommended for women with HER2-positive breast cancer ≥ 1.0 cm in size to increase survival and is considered for women with tumors 0.5-0.9 cm in size. We analyzed compliance with trastuzumab among women with HER2-positive breast cancer in a prospective cohort study. Of 1145 recruited patients with breast cancer, 152 were HER2-positive (13.2 %), of whom 126 had tumors ≥ 1.0 cm; 110/126 (87.3 %) of these initiated trastuzumab. Non-receipt was associated with older age, better prognosis tumors, and with non-receipt of adjuvant chemotherapy. Of the 110 who initiated treatment, 18 (15 %) did not complete treatment, 15 (83 %) of them because of cardiotoxicity. Of 20 women with tumors 0.5-0.9 cm, 5 (25 %) initiated trastuzumab. Compliance with trastuzumab was very high among those with HER2-positive breast cancer, as was the completion of the recommended therapy.

Exploring the use and impact of adjuvant trastuzumab for HER2-positive breast cancer patients in a large UK cancer network. Do the results of international clinical trials translate into a similar benefit for patients in South East Wales?

Background:

Trastuzumab was approved in the United Kingdom for adjuvant treatment of human epidermal growth factor receptor 2 (HER2)+ breast cancer in 2006 at significant economic cost and with limited evidence in smaller T1N0 tumours. The South East Wales Cancer Network covers a population of 1 420 000 and maintains a database of treatments used. We examined this database to ensure the outcome of Trastuzumab use is as expected, especially in patients with T1N0 cancers.

Ethods:

M Case notes of patients with HER2+ disease eligible for adjuvant Trastuzumab over 2005–2008 were reviewed. Disease-free survival (DFS) and overall survival (OS) were calculated with the Kaplan–Meier method using SPSS (version 16.0.01 for Windows, SPSS, Chicago, IL, USA).

Results:

A total of 239 of 338 (70.7%) eligible HER2+ patients received treatment. At 3 years, the DFS of the treated group was 90.3% vs 73.3% and the OS was 98.5% vs 87.6%. In all, 47 of 92 stage I patients received Trastuzumab. Despite a trend towards worse prognostic factors in the treated group the DFS was 100% vs 84.1% and the OS was 100% vs 93.3%.

Conclusion:

Our results are comparable to those from landmark Trastuzumab trials. As evidence continues to emerge that smaller HER2+ cancers may behave aggressively our analysis of stage I tumours adds further support to the use of Trastuzumab in these patients.

A pharmacogenomic method for individualized prediction of drug sensitivity

Using valproic acid as an example, the authors demonstrate that drug response signatures derived from genome-wide expression data can identify individuals likely to respond to a drug, and propose that this method could select optimal populations for clinical trials of new therapies.

Drug response signatures that accurately reflect the cellular response to a drug can be generated from Connectivity Map and publically available gene expression data.

Predictions from the drug response signature for valproic acid correlate with sensitivity to valproic acid in breast cancer cell lines and patient tumors grown in three-dimensional culture and mouse xenografts.

The MATCH algorithm provides an efficient approach for using genome-wide gene expression data to identify a target population for a drug prior to clinical trials.

MATCH can predict drug sensitivity in tumors without knowledge of mechanism of action.

Unlike traditional chemotherapy, targeted cancer therapies are expected to work in only a subset of people with a particular cancer. However, biomarkers of response are not always known before clinical trial initiation. We present MATCH (Merging genomic and pharmacologic Analyses for Therapy CHoice), an algorithm for using genome-wide gene expression data to identify and validate a genomic biomarker of sensitivity (see Figure 1). Our proof-of-principle example is valproic acid (VPA), but we also show that an estrogen blocking drug currently used for breast cancer and a B-RAF inhibitor in trials for melanoma give predictions that correspond to their clinical uses.

We use genome-wide gene expression data from treated and untreated samples from the Connectivity Map to generate a VPA response signature. We validate that the VPA signature can identify treated and untreated cells in an independent data set of normal cells and in independent samples from the Connectivity Map. The AUC for the ROC curve is 0.86. We then apply the VPA signature to publically available data sets from a panel of cancer cell lines and from primary tumor and normal tissue samples. These data suggest that there is a subset of women with breast cancer who will be sensitive to VPA. Finally, we validate that our predictions correlate with sensitivity to VPA in breast cancer cell lines grown in two-dimensional culture, primary breast tumor samples grown in three-dimensional culture, and in vivo mouse breast cancer xenografts. Together, these studies show that MATCH can identify cancer patients most likely to respond to a specific drug treatment.

Identifying the best drug for each cancer patient requires an efficient individualized strategy. We present MATCH (Merging genomic and pharmacologic Analyses for Therapy CHoice), an approach using public genomic resources and drug testing of fresh tumor samples to link drugs to patients. Valproic acid (VPA) is highlighted as a proof-of-principle. In order to predict specific tumor types with high probability of drug sensitivity, we create drug response signatures using publically available gene expression data and assess sensitivity in a data set of >40 cancer types. Next, we evaluate drug sensitivity in matched tumor and normal tissue and exclude cancer types that are no more sensitive than normal tissue. From these analyses, breast tumors are predicted to be sensitive to VPA. A meta-analysis across breast cancer data sets shows that aggressive subtypes are most likely to be sensitive to VPA, but all subtypes have sensitive tumors. MATCH predictions correlate significantly with growth inhibition in cancer cell lines and three-dimensional cultures of fresh tumor samples. MATCH accurately predicts reduction in tumor growth rate following VPA treatment in patient tumor xenografts. MATCH uses genomic analysis with in vitro testing of patient tumors to select optimal drug regimens before clinical trial initiation.

HER2 evaluation and its impact on breast cancer treatment decisions

BACKGROUND

Eighteen to twenty percent of breast cancer tumors show abnormal amplification of the Human Epidermal growth factor Receptor 2 (HER2) gene and increased expression of the associated protein. HER2 amplification is associated with rapid tumor proliferation and shorter disease-free and overall survival. Because women with HER2 amplification are more likely to benefit from treatment with the drug trastuzumab, testing for HER2 is recommended to guide therapy. However, little is known about use of HER2 testing in real-world settings. This study examined uptake, use, appropriateness of HER2 testing, and the relationship between HER2 test results and treatment decisions.

METHODS

We assessed electronic data from 3,634 patients with invasive breast cancer diagnosed from 1998 to 2007 in a large integrated health system. We collected data on patient and tumor characteristics, HER2 testing status, test results, and trastuzumab treatment.

RESULTS

From 1998 to 2000, the percent of patients who underwent HER2 evaluation increased from 12 to 94%; <3% of women with ductal carcinoma in situ, for whom HER2 testing is not recommended, were tested. Trastuzumab use increased 5-fold after 2004, when guidelines expanded to include recommending adjuvant treatment for early-stage breast cancer in addition to metastatic treatment. Ninety-five percent of women receiving trastuzumab had a positive HER2 result. After 2004, 55% of women with invasive breast cancer and overexpression of HER2 received trastuzumab treatment; this ranged from 44% of women with localized breast cancer to 80% of women with distant metastatic disease.

CONCLUSIONS

These findings illustrate appropriate and effective implementation of a HER2 testing strategy in a managed care setting.

Genomic testing and therapies for breast cancer in clinical practice

PURPOSE

Given the likely proliferation of targeted testing and treatment strategies for cancer, a better understanding of the utilization patterns of human epidermal growth factor receptor 2 (HER2) testing and trastuzumab and newer gene expression profiling (GEP) for risk stratification and chemotherapy decision making are important.

STUDY DESIGN

Cross-sectional.

METHODS

We performed a medical record review of women age 35 to 65 years diagnosed between 2006 and 2007 with invasive localized breast cancer, identified using claims from a large national health plan (N = 775).

RESULTS

Almost all women received HER2 testing (96.9%), and 24.9% of women with an accepted indication received GEP. Unexplained socioeconomic differences in GEP use were apparent after adjusting for age and clinical characteristics; specifically, GEP use increased with income. For example, those in the lowest income category (< $40,000) were less likely than those with an income of $125,000 or more to receive GEP (odds ratio, 0.34; 95% CI, 0.16 to 0.73). A majority of women (57.7%) with HER2-positive disease received trastuzumab; among these women, differences in age and clinical characteristics were not apparent, although surprisingly, those in the lowest income category were more likely than those in the high-income category to receive trastuzumab (P = .02). Among women who did not have a positive HER2 test, 3.9% still received trastuzumab. Receipt of adjuvant chemotherapy increased as GEP score indicated greater risk of recurrence.

CONCLUSION

Identifying and eliminating unnecessary variation in the use of these expensive tests and treatments should be part of quality improvement and efficiency programs.