Molecular Subtype Profile Reveals Therapy Predictive Power

BackgroundClassification of breast cancers into molecular subtypes may be important for accurate selection of therapy for patients. Here we report the respective chemotherapy responsiveness of the molecular subtypes profile defined Luminal, ERBB2 and Basal type.MethodsAn 80-gene subtype profile was developed based on a series of 200 samples with concordant ER, PR and Her2 receptor IHC and single gene readout status. Previously we reported the excellent validation of the profile classification using 784 samples. Here we report a second in silico validation consisting of 133 samples (Hess et al, JCO, 2006) which tested the profile as a predictor of pathological Complete Response (pCR) in these patients treated with T/FAC neoadjuvant chemotherapy.ResultsIn the 133 publicly available samples the profile classified 62% (82) as Luminal-type, 18% (24) as ERBB2-type and 20% (27) as Basal-type. These results were consistent with percentages found in the training and validation cohorts (n=1079; 295 training and 784 validation samples); 66% (712) Luminal-type, 18% (194) as ERBB2-type and 16% (173) Basal-type. Chemotherapy response was measured by pathological Complete Response (pCR) at the time of surgery In the Luminal-type subgroup 9% (7) of patients showed pCR, in the ERBB2-type subgroup 50% (12) of patients had a pCR and in the Basal-type subgroup 56% (15) of patients had a pCR.ConclusionsThe developed multi-gene profile can classify breast cancer tumors into Luminal-, ERBB2- and Basal-type subgroups. Within the subgroups, a significant difference in chemotherapy response, as measured by pCR, is observed. Implementation of this knowledge may improve the clinical management of breast cancer patients, by enabling the physician to decide who is most likely to benefit from chemotherapy or endocrine therapy prior to surgery.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6131.

Basal-, Luminal-, and HER2- Molecular Subtype, and the MammaPrint 70-Gene Signature as Predictors of Response to Neoadjuvant Chemotherapy (NCT) with Docetaxel, Doxorubicin, Cyclophosphamide (TAC), or AC and Nab-Paclitaxel and Carboplatin +/- Trastuzumab in Patients (Pts) with Stage II-III and Inflammatory Breast Cancer (BC)

Background: Pathologic complete response (pCR) and minimal residual cancer burden (RCB scores of 0 [pCR]-1[near CR]) after NCT may predict for improved survival (Symmans et al. J Clin Oncol 25:4414-22, 2007). Hence, improved NCT regimens in conjunction with molecular markers that predict for both response and/or resistance are needed. Materials and Methods: 115 pts with stages II-III BC were to be prospectively randomized to receive 6 cycles of docetaxel 75 mg/m2, doxorubicin 50 mg/m2, cyclophosphamide 500 mg/m2 with filgrastim support (TAC, arm A) versus a novel regimen of A 60 mg/m2 and C 600 mg/m2 given every 2 weeks x 4, followed by 3 weekly doses of carboplatin (AUC 2) and nab-paclitaxel 100 mg/m2 repeated as 28 day cycles x 3 (arm B). Pts with HER2 + BC received NCT similar to arm B, but with the addition of 12 weekly doses of trastuzumab given together with carboplatin and nab-paclitaxel (arm C). Core biopsies were performed prior to NCT and were preserved fresh frozen. 70-gene (MammaPrint™) profiling and 80-gene profiling (van de Vijver et al. NEJM 347:1999-2009, 2002) to categorize all tumors for basal-, HER2-, and luminal subtypes were carried out. We set out to assess the predictive value of Mammaprint scores (poor vs. good), as well as basal, vs. luminal, vs. HER2 molecular subtype profiling, for response to treatment on arms A vs. B vs. C. Responses were dichotomized as complete or near complete response (Symmans RCB scores of 0-1) vs. suboptimal response (RCB score > 1). Results: Sufficient amount of BC tissue and good quality RNA for gene array assessment were procured in 64% of the first 90 patients who have undergone pre-treatment core biopsies, and then proceeded to NCT, followed by definitive surgery. Here we report on the first 50 pts with complete set of data analyzed. The median age was 50 years (range:31-69). Pts were treated for stage II (49%) and III locally advanced (41%), and inflammatory BC (10%). By gene profiling, 28% of the tumors were HER2-type (vs. 38% by IHC 3+, or FISH, representing all pts treated on arm C), 26% basal-type, 42% luminal-type, and 4% borderline luminal-type. Poor-prognosis signature by the 70-gene (MammaPrint) assay was observed in 74% of pts: 92% of HER2-type, 100% of basal-type, and 52% of luminal-type tumors were characterized as poor-risk by the 70-gene assay. Following NCT, Symmans RCB scores of 0-1 were observed in 71% of pts with HER2-type, in 38% with basal-type, and 28% of pts with luminal-type molecular subtype characteristics. Conclusion: BC with HER2- and basal-molecular subtypes are more likely to respond to NCT and is frequently associated with poor-risk characteristics as determined by the 70-gene assay. The complete analysis of correlations among response to specific sets of NCT, molecular subtype, and 70-gene assay results in the entire pt population will be presented.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2026.

Risk of malignancies in patients with diabetes treated with human insulin or insulin analogues: a cohort study

AIMS/HYPOTHESIS

The aim of this cohort study was to investigate the risk of malignant neoplasms and mortality in patients with diabetes treated either with human insulin or with one of three insulin analogues.

METHODS

Data were provided by the largest German statutory health insurance fund (time-frame: January 1998 to June 2005 inclusive), on patients without known malignant disease who had received first-time therapy for diabetes mellitus exclusively with human insulin, aspart, lispro or glargine. The primary outcome was the diagnosis of a malignant neoplasm. Data were analysed by multiple Cox regression models adjusting for potential confounders.

RESULTS

A total of 127,031 patients were included, with a mean follow-up time of 1.63 (median 1.41, maximum 4.41) years. A positive association between cancer incidence and insulin dose was found for all insulin types. Because patients receiving combined therapy with insulin analogues and human insulin were excluded, the mean daily dose was much lower for glargine than for human insulin, and a slightly lower cancer incidence in the glargine group was found. After adjusting for dose, a dose-dependent increase in cancer risk was found for treatment with glargine compared with human insulin (p < 0.0001): the adjusted HR was 1.09 (95% CI 1.00 to 1.19) for a daily dose of 10 IU, 1.19 (95% CI 1.10 to 1.30) for a daily dose of 30 IU, and 1.31 (95% CI 1.20 to 1.42) for a daily dose of 50 IU. No increased risk was found for aspart (p = 0.30) or lispro (p = 0.96) compared with human insulin.

CONCLUSIONS/INTERPRETATION

Considering the overall relationship between insulin dose and cancer, and the lower dose with glargine, the cancer incidence with glargine was higher than expected compared with human insulin. Our results based on observational data support safety concerns surrounding the mitogenic properties of glargine in diabetic patients. Prospective long-term studies are needed to further evaluate the safety of insulin analogues, especially glargine.

Cost-effectiveness of targeting chemotherapy with the 70-gene prognostic signature in early-stage breast cancer (ESBC) patients

6570

Background: The 70-gene microarray test (MammaPrint) has been shown to provide additional prognostic information to clinicopathologic risk assessment for women ESBC; however, the cost-effectiveness of this strategy is not well understood. Methods: The objective of this analysis was to estimate the incremental benefits, costs, and cost-effectiveness of the treatments guided by the 70-gene signature versus Adjuvant! Software (AS) to decide on the use of adjuvant chemotherapy for women ≤61 years with lymph node negative, HER-2 negative ESBC with estrogen receptor (ER) positive or negative disease. A Markov model with a lifetime horizon and three health states (alive without recurrence, death from cancer and death from other causes) was constructed using TreeAge Pro software. Risk classification and patient outcomes data were based on a multi-center 70-gene signature validation study. Efficacy of chemotherapy derived from published meta-analysis of clinical trials. Costs and health utilities were obtained from the literature. Costs and benefits were discounted 3%/year. Results: Compared to AS, the 70-gene signature strategy resulted in 35% of patients being reassigned to a different risk classification and avoided chemotherapy in 9% of patients. In the base case, the 70-gene signature strategy was cost neutral (lifetime costs per patient: $178,811 versus $178,893 for the 70-gene signature and AS strategy). Moreover the 70-gene signature strategy was associated with an increase of 0.13 life years (LYs) and 0.16 quality adjusted life years (QALYs). The model results were sensitive to the cost of 70-gene signature test, cost of adjuvant chemotherapy, and relative risk reduction associated with chemotherapy; however, the 70-gene strategy remained cost-effective across a wide range of assumptions. Conclusions: In this analysis, the 70-gene signature was associated with a reduction in chemotherapy use and an increase in life expectancy. The 70-gene signature appears to be a cost-effective strategy for obtaining additional information to guide the decision to use adjuvant chemotherapy in patients with lymph node negative ESBC.

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Microarray-based determination of ER, PR and HER2 receptor status: validation and comparison with IHC assessments

Abstract #3007

Background&#x2028; In breast cancer patients the level of expression of estrogen receptor (ER), progesterone receptor (PR) and HER2 is predictive for prognosis and/or treatment response. However, differences in assessment methods and interpretation can substantially affect the accuracy and reproducibility of the results. Previously, we have determined the association between immunohistochemistry (IHC) and mRNA levels for ER, PR and HER2, and have confirmed the accuracy of microarray readout on &gt;400 samples. In the current study we describe the use of this microarray based readout on prospectively collected samples. We compared these readouts with multiple IHC and fluorescent in situ hybridization (FISH) assessments generated in various hospitals and a CLIA-certified reference laboratory and developed a microarray based test called TargetPrint™.&#x2028; Methods&#x2028; Gene expression data for ER, PR and HER2 were obtained by analysis of 100 breast carcinomas that have been collected prospectively within the RASTER study. Samples were stratified as receptor positive or negative using thresholds for ER, PR and HER2 mRNA levels. IHC assessment was performed (1) according to local standards of the hospital from where the sample originated, (2) by the central laboratory of the Netherlands Cancer Institute, and (3) at an independent reference laboratory using FDA-approved procedures and ASCO/CAP guidelines. A tumor was classified positive for ER and PR when ≥10% of tumor cells showed positive staining. HER2 IHC status was scored as 0, 1+, 2+ or 3+; a score of 3+ was considered positive. In case of 2+ samples, a FISH was performed to assess final HER2 amplification status. The cohort used in this study was pre-selected to include about two-third ER and PR positive samples and one-third HER2 positive samples.&#x2028; Results&#x2028; Multiple microarray readouts were highly reproducible (Pearson correlation 0.991) and resulted in 67, 61 and 39 percent positive samples for ER, PR and HER2, respectively. Comparison of microarray results with IHC (including FISH for HER2) performed at the three centers indicated highly similar results for receptor readout with a concordance of 92, 93 and 92% for ER; 84, 81 and 86% for PR; and 93, 95 and 94% for HER2. Overall misclassification rates between microarray and IHC readout were low for ER (0.08) and HER2 (0.06) and quite low for PR (0.14), and were comparable to the misclassification rates between the three IHC methods.&#x2028; Conclusion&#x2028; A microarray-based assessment of ER, PR and HER2 in relation to mRNA levels gives results comparable to multiple IHC methods and FISH and provides an objective and more quantitative assessment of tumor receptor status than IHC alone. Using TargetPrint™ for microarray readouts for hormone and HER2 receptor in addition to standard IHC will improve molecular characterization of breast cancer tissue.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3007.

Können Mindestmengen für Knieprothesen anhand von Routinedaten errechnet werden?

AIM OF THE STUDY

The aim of this study was to calculate, for the first time, minimum provider volumes in total knee replacement using routine German data.

MATERIALS AND METHODS

In patients with primary total knee replacement (TKR), the relationship between hospital volume per year and risk of "insufficient mobility" (primary quality indicator) and "wound infection" (secondary quality indicator) was calculated by means of logistic regression models.

RESULTS

For both indicators, a statistically significant relationship between hospital volume and outcome could be demonstrated. Other risk factors such as age and ASA status also had a significant influence, but did not appear as important confounders. The risk for the secondary quality indicator "infection" decreased constantly with increasing hospital volume, thus the curve was very flat. This supports the hypothesis that high volume hospitals have a higher quality level than low volume hospitals. A threshold value could be calculated. However, the explanation value for hospital volume was too low to derive a threshold level that clearly discriminates between good and bad quality of care. The relationship between the primary quality indicator "insufficient mobility" and hospital volume unexpectedly showed a U-shaped distribution. This questions the concept of a minimum provider volume regulation for primary total knee replacement for the quality indicator "insufficient mobility". Therefore, in this case no quantitative threshold values were calculated.

CONCLUSION

This analysis supports the hypothesis of a volume-outcome relationship in primary total knee replacement. However, a minimum provider volume that clearly discriminates between good and bad quality of care could not be calculated on the basis of these German quality assurance data.