Is There a Role for Oncotype Dx Testing in Invasive Lobular Carcinoma?

Oncotype Dx Breast Cancer Assay is a 21-gene assay used in estrogen receptor (ER)-positive breast cancer to predict benefit from chemotherapy (CT). Tumors are placed into one of three risk categories based on their recurrence score (RS). This paper explores the impact of tumor histopathologic features and Oncotype Dx RS on the treatment plan for invasive lobular carcinoma (ILC). Invasive lobular carcinoma cases submitted for Oncotype Dx testing were identified from a clinical data base. The histopathologic and immunohistochemical features and RS subcategory of each tumor, and treatment regimen and medical oncologic assessments of each patient were reviewed. A total of 135 cases of ILC had RS testing, which represented 15% of all ILC diagnosed at the institution over the time period. 80% of ILC was of the classical subtype and all tumors were ER positive and human epidermal growth factor receptor 2 (HER-2) negative by immunohistochemistry. Sixty three percent of cases were low risk (LR), 35.5% were intermediate risk (IR) and 1.5% were high risk (HR). Both HR cases were pleomorphic ILC. Sixty eight percent of classical ILC had a LR score, while 70% of pleomorphic ILC had an IR score. Patients in the IR category were significantly more likely to undergo CT than patients in the LR category (54% versus 18%; p < 0.0001). In the LR category, those undergoing CT were significantly younger and more likely to have positive lymph nodes (p < 0.05). Qualitative analysis of medical oncologic assessments showed that RS played a role in decision-making on CT in 74% of cases overall. At our institution, Oncotype Dx RS currently plays a role in the management of a proportion of ILC and impacts on treatment decisions.

Coverage policy development for personalized medicine: private payer perspectives on developing policy for the 21-gene assay

PURPOSE

Personalized medicine is changing oncology practice and challenging decision making. A key challenge is the limited clinical evidence for many personalized medicine technologies. We describe the strategies private payers employed to develop coverage policy for personalized medicine using the example of the 21-gene assay in breast cancer.

METHODS

We examined the coverage policies of six private payers for the 21-gene assay. We then interviewed senior executives (n = 7) from these payers to elucidate factors informing coverage decisions. We additionally focused on the timing of payer decisions compared with the timing of evidence development, measured by publication of primary studies and relevant clinical guidelines.

RESULTS

The 21-gene assay became commercially available in 2004. The interviewed payers granted coverage between 2005 and 2008. Their policies varied in structure (eg, whether prior authorization was required). All payers reported clinical evidence as the most important factor in decision making, but all used some health care system factors (eg, physician adoption or medical society endorsement) to inform decision making as well. Payers had different perceptions about the strength of clinical evidence at the time of the coverage decision.

CONCLUSION

Coverage of the 21-gene assay is currently widespread, but policies differ in timing and structure. A key approach private payers use to develop coverage policies for novel technologies is considering both clinical evidence and health care system factors. Policy variation may emerge from the range of factors used and perception of the evidence. Future research should examine the role of health care system factors in policy development and related policy variations.

Review of the clinical studies using the 21-gene assay

PURPOSE

A major challenge in treating early-stage hormone receptor (HR)(+) breast cancer is selecting women who, after initial surgery, do not require chemotherapy. Better prognostic and predictive tests are needed. The 21-gene assay is the only widely commercially available gene signature that can be performed on formalin-fixed paraffin-embedded tissue.

METHODS

We conducted a review of the literature supporting the prognostic and predictive ability of the 21-gene assay in HR(+) node-negative and node-positive breast cancer patients in chemotherapy-/endocrine-treated and untreated populations. We considered: (a) How accurate is the recurrence score (RS) as a prognostic factor for distant recurrence? (b) How accurate is the RS as a predictive factor for benefit from systemic therapy? (c) How does the RS compare with other prognostic/predictive factors such as tumor size, tumor grade, patient age, and integrated decision aids such as Adjuvant! Online? (d) How do patients and physicians view the 21-gene assay? (e) What are the cost implications of the 21-gene assay?

RESULTS

The 21-gene assay: (a) provided accurate risk information; (b) predicted response to cyclophosphamide, methotrexate, and 5-fluorouracil and to cyclophosphamide, doxorubicin, and 5-fluorouracil chemotherapy; (c) added additional information to traditional biomarkers; (d) was viewed positively by both physicians and patients; and (e) fell within the cost-effectiveness values in North America.

CONCLUSION

This assay may be offered to patients with node-negative HR(+) breast cancer to assist in adjuvant treatment decisions. Data are accumulating to support the use of the 21-gene assay in HR(+) node-positive patients.

Verification of a prolonged untreated natural history of breast cancer by the multigene assay

Individualization of therapy for breast cancer patients has progressed significantly over the last 5 years. A 54-year-old female went over 2 years after her diagnosis of breast cancer with no treatment. The pathologic size, however, indicated that the tumor may not have progressed from diagnosis to operation. Due to the apparent lack of progression over 2 years without treatment, a multigene assay was ordered. The recurrence score was 15, indicating a less than 10% risk of distant recurrence at 10 years. The recurrence score also falls into the "low risk" category. The prolonged natural history of this breast cancer patient suggested an indolent cancer. The "low risk" recurrence score confirmed this history and indicated that adjuvant chemotherapy is probably not beneficial to this patient.

Novel molecular prognostic markers in breast cancer

BACKGROUND

Advances in the treatment of breast cancer have led to a reduction in breast-cancer-related mortality. However, these therapies are known to be associated with toxicities. Thus there is a crucial need to accurately define the populations of women with an excellent prognosis who may safely avoid the risks of systemic therapy. Recent developments utilizing novel technologies that incorporate our growing understanding of the biology and pathophysiology of breast cancer strive to better identify these patients.

OBJECTIVE

To provide a review of newer prognostic markers with a focus on the 21-gene recurrence score (Oncotype DX(™)), 70-gene prognosis profile (Mammaprint(®)), and Adjuvant! Online.

CONCLUSION

These techniques differ in their execution and application and have been demonstrated to provide further data on risk stratification as compared with conventional breast-cancer-risk factors.

Commercialized multigene predictors of clinical outcome for breast cancer

In the past 5 years, a number of commercialized multigene prognostic and predictive tests have entered the complex and expanding landscape of breast cancer companion diagnostics. These tests have used a variety of formats ranging from the familiar slide-based assays of immunohistochemistry and fluorescence in situ hybridization to the nonmorphology-driven molecular platforms of quantitative multiplex real-time polymerase chain reaction and genomic microarray profiling. In this review, 14 multigene assays are evaluated as to their scientific validation, current clinical utility, regulatory approval status, and estimated cost-benefit ratio. Emphasis is placed on two tests: oncotype DX and MammaPrint. Current evidence indicates that the oncotype DX test has the advantages of earlier commercial launch, wide acceptance for payment by third-party payors in the U.S., ease of use of formalin-fixed paraffin-embedded tissues, recent listing by the American Society of Clinical Oncology Breast Cancer Tumor Markers Update Committee as recommended for use, continuous scoring system algorithm, ability to serve as both a prognostic test and predictive test for certain hormonal and chemotherapeutic agents, demonstrated cost-effectiveness in one published study, and a high accrual rate for the prospective validation clinical trial (Trial Assigning Individualized Options for Treatment). The MammaPrint assay has the advantages of a 510(k) clearance by the U.S. Food and Drug Administration, a larger gene number, which may enhance further utility, and a potentially wider patient eligibility, including lymph node-positive, estrogen receptor (ER)-negative, and younger patients being accrued into the prospective trial (Microarray in Node-Negative Disease May Avoid Chemotherapy). A number of other assays have specific predictive goals that are most often focused on the efficacy of tamoxifen in ER-positive patients, such as the two-gene ratio test and the cytochrome P450 CYP2D6 genotyping assay.

Does oncotype DX recurrence score affect the management of patients with early-stage breast cancer?

BACKGROUND

Oncotype DX is a 21-gene assay that calculates a risk of distant recurrence in women with estrogen-receptor-positive, lymph node-negative breast cancer. The purpose of this study was to determine whether the results of Oncotype DX influence the decision to administer chemotherapy.

METHODS

A retrospective study was performed on 85 consecutive patients with estrogen-receptor-positive, lymph node-negative breast cancer who had an Oncotype DX recurrence score (RS) obtained. Tumor size, tumor grade, and treatment were then compared within each risk category. Statistical analysis was performed using STATA software.

RESULTS

Tumors that were high grade and Her-2/neu positive more frequently had a high RS. Treatment was changed as a result of Oncotype DX in 44% of patients.

CONCLUSIONS

Oncotype DX RS is significantly related to tumor grade and Her2/neu status. In this study, the treatment of 44% of patients was altered as a consequence of Oncotype DX RS.

When genomic and standard test results diverge: implications for breast cancer patients' preference for chemotherapy

PURPOSE

We examined how women incorporate potentially differing genomic and standard assessments of breast cancer recurrence risk into chemotherapy decisions.

METHODS

165 women previously treated for early-stage breast cancer indicated their interest in chemotherapy regimens to prevent recurrence of breast cancer in response to six hypothetical vignettes that presented breast cancer recurrence risk estimates from standard criteria and a genomic test, some of which were discordant.

RESULTS

Standard and genomic test results each elicited greater interest in chemotherapy when they indicated high rather than low risk for recurrence (89% vs. 26%, and 87% vs. 22%, respectively, Ps < 0.001). Genomic test results had a larger impact on chemotherapy preferences than standard measures to predict recurrence.

CONCLUSIONS

Some women may be reluctant to forgo chemotherapy when genomic tests indicate low recurrence risk but standard criteria suggest high risk. Additional research including replication of the findings of this small, vignette-based study is needed.

Development of a clinically feasible molecular assay to predict recurrence of stage II colon cancer

The 5-year survival rate for patients with Stage II colon cancer is approximately 75%. However, there is no clinical test available to identify the 25% of patients at high risk of recurrence. We have previously identified a 23-gene signature that predicts individual risk for recurrence. The present study tested this gene signature in an independent group of 123 Stage II patients, and the 23-gene signature was highly informative in identifying patients with distant recurrence in both univariate (hazard ratio [HR] 2.51) and multivariate analyses (HR, 2.40). The composition of this representative patient group also allowed us to refine the 23-gene signature to a 7-gene signature that exhibited a similar prognostic power in both univariate (HR, 2.77) and multivariate analyses (HR, 2.87). Furthermore, we developed this prognostic signature into a clinically feasible test with real-time quantitative PCR using standard fixed paraffin-embedded tumor tissues. When a 110-patient cohort was evaluated with the PCR assay, the 7-gene signature, demonstrated to be a strong prognostic factor in both univariate (HR, 6.89) and multivariate analyses (HR, 14.2). These results clearly show the prognostic value of the predefined gene signature for Stage II colon cancer patients. The ability to identify colon cancer patients with an unfavorable outcome may help patients at high risk for recurrence to seek more aggressive therapy.

Development of the 21-gene assay and its application in clinical practice and clinical trials

Several multigene markers that predict relapse more accurately than classical clinicopathologic features have been developed. The 21-gene assay was developed specifically for patients with estrogen receptor (ER)-positive breast cancer, and has been shown to predict distant recurrence more accurately that classical clinicopathologic features in patients with ER-positive breast cancer and negative axillary nodes treated with adjuvant tamoxifen; validation studies in this population led to its approval as a diagnostic test. In a similar population, it also may be used to assess the benefit of adding chemotherapy to hormonal therapy. Other validation studies indicate that it also predicts the risk of distant and local recurrence in other populations with ER-positive disease, including node-negative patients receiving no adjuvant therapy and patients with positive axillary nodes treated with doxorubicin-containing chemotherapy. The Trial Assigning Individualized Options for Treatment (TAILORx) is multicenter trial that integrates the 21-gene assay into the clinical decision-making process and is designed to refine the utility of the assay in clinical practice and to provide a resource for evaluating additional molecular markers as they are developed in the future.