Breast Cancer Index and prediction of benefit from extended endocrine therapy in breast cancer patients treated in the Adjuvant Tamoxifen-To Offer More? (aTTom) trial

BACKGROUND

Extending the duration of adjuvant endocrine therapy reduces the risk of recurrence in a subset of women with early-stage hormone receptor-positive (HR+) breast cancer. Validated predictive biomarkers of endocrine response could significantly improve patient selection for extended therapy. Breast cancer index (BCI) [HOXB13/IL17BR ratio (H/I)] was evaluated for its ability to predict benefit from extended endocrine therapy in patients previously randomized in the Adjuvant Tamoxifen-To Offer More? (aTTom) trial.

PATIENTS AND METHODS

Trans-aTTom is a multi-institutional, prospective-retrospective study in patients with available formalin-fixed paraffin-embedded primary tumor blocks. BCI testing and central determination of estrogen receptor (ER) and progesterone receptor (PR) status by immunohistochemistry were carried out blinded to clinical outcome. Survival endpoints were evaluated using Kaplan-Meier analysis and Cox regression with recurrence-free interval (RFI) as the primary endpoint. Interaction between extended endocrine therapy and BCI (H/I) was assessed using the likelihood ratio test.

RESULTS

Of 583 HR+, N+ patients analyzed, 49% classified as BCI (H/I)-High derived a significant benefit from 10 versus 5 years of tamoxifen treatment [hazard ratio (HR): 0.35; 95% confidence interval (CI) 0.15-0.86; 10.2% absolute risk reduction based on RFI, P = 0.027]. BCI (H/I)-low patients showed no significant benefit from extended endocrine therapy (HR: 1.07; 95% CI 0.69-1.65; -0.2% absolute risk reduction; P = 0.768). Continuous BCI (H/I) levels predicted the magnitude of benefit from extended tamoxifen, whereas centralized ER and PR did not. Interaction between extended tamoxifen treatment and BCI (H/I) was statistically significant (P = 0.012), adjusting for clinicopathological factors.

CONCLUSION

BCI by high H/I expression was predictive of endocrine response and identified a subset of HR+, N+ patients with significant benefit from 10 versus 5 years of tamoxifen therapy. These data provide further validation, consistent with previous MA.17 data, establishing level 1B evidence for BCI as a predictive biomarker of benefit from extended endocrine therapy.

TRIAL REGISTRATION

ISRCTN17222211; NCT00003678.

Abstract P2-08-42: Use of breast cancer index to analyze tumor proliferation and endocrine responsiveness in genomic intermediate risk patients

Background: Breast Cancer Index (BCI) is a genomic assay that stratifies patients (pts) for cumulative 10-year and late (post–5-year) risk of distant recurrence and predicts the likelihood of extended endocrine therapy (EET) benefit based on the algorithmic analysis of gene expression from two functional gene cassettes: 1) The Molecular Grade Index (MGI), which contains 5 proliferation genes and 2) The HoxB13/IL17BR (H/I) ratio, an endocrine response biomarker. BCI more precisely resolves genomic intermediate risk patients into low- and high-risk groups (Sestak, Clin Cancer Res 2016) and adds significant prognostic data beyond clinical features (ie, clinical treatment score; Sestak, JAMA Oncol 2017) by interrogating different aspects of tumor biology such as proliferation and endocrine response. The objective of this study was to measure tumor proliferation and endocrine responsiveness using MGI and H/I respectively and evaluate their correlation with age in genomic intermediate risk pts.

Methods: This study utilized a subset of cases from the BCI Clinical Database for Correlative Studies, an IRB-approved de-identified database that contains clinicopathologic and molecular variables from clinical cases submitted for BCI testing. Genomic intermediate risk cases were defined as LN-, HER2- (or HER2 status unknown) with 21-gene recurrence scores (RS) of 11 to 25 using cut-points from the TAILORx study. Quantitative scores for MGI and H/I were derived by algorithmic analysis of BCI gene expression. Age groups (<50y and ≥51y) were determined using the date of diagnosis. MGI and H/I were evaluated in two different genomic intermediate risk groups: RS 11-15 and RS 16-25. Pearson correlation coefficients were used to determine the correlation between MGI, BCI, H/I, and genomic intermediate risk scores for patients <50y and ≥51y.

Results: Of the 441 pts with RS and BCI results, 303 (69%) with genomic intermediate risk were analyzed. The median MGI score in pts ≥51y was higher in the RS 16-25 group compared to RS 11-15, but there was no difference in MGI score between the two genomic intermediate RS risk groups for pts <50y. In contrast to MGI, median H/I was higher in the RS 16-25 group irrespective of age, with 37% of pts <50y and 41% of pts ≥51y having tumors predicted as more likely to benefit from EET using validated cut-points for H/I. There was no significant correlation between tumor proliferation (MGI: r=0.166) or endocrine responsiveness (H/I: r=0.244) with genomic intermediate-risk RS 11-25 group.

Conclusion: These data, which show variations in tumor proliferation and endocrine signaling based on age and genomic intermediate risk group, highlight the importance of measuring different features of tumor biology for risk classification and prediction of therapy response. The absence of correlations between tumor proliferation and genomic intermediate risk and age, and between estrogen signaling and genomic intermediate risk and age, suggests that assays such as BCI that combine distinct aspects of tumor biology for prognosticating risk of recurrence and prediction of benefit from endocrine therapy provide additional value for individualizing the management of patients with early-stage ER+ breast cancer.

Citation Format: Yan F, Master AK, Israel MA, Liu J, Zhang Y, Schnabel CA, Gadi VK. Use of breast cancer index to analyze tumor proliferation and endocrine responsiveness in genomic intermediate risk patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-42.

Abstract P5-04-22: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Treuner K, Hayes M, Schnabel CA, Heinz S. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-04-22.

Abstract P6-09-03: Gene expression patterns in younger versus older HR+ breast cancer patients: An age-related analysis of HoxB13/IL17BR (H/I), proliferation status, and quantitative hormone receptor expression

Background: HR+ breast cancer in younger vs older patients may have distinct biological features. The Breast Cancer Index (BCI) is a gene expression-based assay that includes two component biomarkers: the HoxB13/IL17BR (H/I ratio), an endocrine response biomarker; and the molecular grade index (MGI), a set of proliferation-related genes. The objective of this study was to assess age-related associations with endocrine sensitivity (H/I), proliferative status (MGI), and quantitative expression of ER and PR.

Methods: Data were extracted from the BCI Clinical Database for Correlative Studies, an IRB-approved de-identified database containing clinicopathologic and molecular variables from clinical cases submitted for BCI testing. Molecular results from H/I, MGI, and quantitative (qPCR–based) ER and PR were analyzed across age groups. Chi-squared tests and ANOVA were used to compare the results between age groups (<40y, 40-49y, 50-59y, 60-69y, and ≥70y).

Results: Analyses included 19,126 patients (median age at diagnosis 58.6y; 4.5% <40y, 20.6% 40-49y, 28.9% 50-59y, 32.5% 60-69y, and 13.6% ≥70y). Proliferation status (MGI) was significantly higher in patients <40y and 40-49y compared to older groups (P<.0001).H/I analysis indicated a similar distribution of high versus low endocrine responsiveness across all groups (P=.94), except the 40-49y group, in which fewer patients had high H/I (44.2% in <40y, 39.4% in 40-49y, 43.7% in 50-59y, 43.7% in 60-69y, and 43.1% in ≥70y; P=.0001). Median qER increased with age (P<0.0001), while qPR was similar across all age groups except for the 40-49y group (P=.57), in which expression was higher (P<.0001).

Conclusion: Results from >19,000 patients with early-stage HR+ breast cancer and BCI testing showed a broad distribution in all variables. Tumors from the youngest patients (<40y) had the highest expression of proliferative genes and the lowest quantitative ER expression. However, endocrine response, according to the H/I biomarker, does not appear to be strongly linked to age.

Citation Format: Melisko M, Chien AJ, Poage GM, Salganik M, Schnabel CA, Ruddy KJ, Blackwell K. Gene expression patterns in younger versus older HR+ breast cancer patients: An age-related analysis of HoxB13/IL17BR (H/I), proliferation status, and quantitative hormone receptor expression [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-09-03.

Abstract P1-06-10: Correlative analysis of breast cancer index (BCI) restratification of 21-gene recurrence score (RS) in patients with hormone receptor-positive (HR+), node-negative breast cancer

Background: In a cross-stratification analysis performed within the TransATAC cohort, Breast Cancer Index (BCI) and 21-gene Recurrence Score (RS) had a concordance of 58.2% (Sestak et al., Clin Cancer Res, 2016). Restratification by BCI of the low and intermediate RS risk groups led to subgroups with significantly different rates (P < 0.001 and P = 0.003, respectively); in contrast, restratified subgroups created by RS of BCI risk groups did not differ significantly. The objective of this study was to analyze the concordance of BCI and RS test results in HR+, node-negative (LN-) patients tested in the real-world setting and to investigate molecular, clinical, and pathologic correlates within discrepant cases.

Methods: This study utilized a subset of cases from the BCI Clinical Database for Correlative Studies, an IRB-approved de-identified database which contains clinicopathologic and molecular variables from clinical cases submitted for BCI testing. Clinicopathologic variables, abstracted from pathology reports, were available for a subset of cases. This analysis evaluated cases from LN- patients with available RS data. Concordance was evaluated between BCI Prognostic risk groups (Low, High) and RS risk groups (Low, Intermediate, High based on TAILOR Rx cutpoints [0-10, 11-25, and 26+]). Fisher's Exact tests were used to compare molecular (HoxB13/IL17BR [H/I] endocrine response biomarker and Molecular Grade Index [MGI] proliferation marker) and clinicopathologic (age, grade, size, HER2, Ki67) data in discrepant risk groups.

Results: There were 456 LN- patients included. Median age was 58.0y (range 27.2-84.0y; 73.9% ≥50y); 33.1%/50.1%/16.8% were grade 1/2/3; and 24.0%/59.5%/15.3% were T1ab/T1c/T2. BCI classified 47.8% (n=218) of patients as Low Risk vs 52.2% (n=238) as High Risk. RS classified 17.1% (n=78), 67.1% (n=306), and 15.8% (n=72) of patients as Low, Intermediate, and High Risk, respectively. BCI restratified RS-Low patients as high risk in 17.1% of cases, restratified RS-Intermediate as Low Risk in 48.4% and High Risk in 51.6%, and restratified RS-High as Low risk in 20.8% of cases. In RS-Low patients, only H/I (P=0.0004) and MGI (P=0.047) were significantly correlated with restratification to BCI-High Risk. In RS-Intermediate patients, H/I (P<0.0001), MGI (P<0.0001), grade (P<0.0001), and Ki67 >20% (P=0.0003) were significantly correlated with restratification by BCI to High or Low Risk. In RS-High patients, H/I (P=0.0008), MGI (P<0.0001), grade (P=0.016) were significantly correlated with restratification to Low Risk.

Conclusion: BCI restratified a substantial proportion of patients in each RS risk group. Based on previous studies demonstrating that BCI has improved prognostic ability for assessment of risk of late distant recurrence (Sgroi et al., Lancet Oncol, 2013), these results highlight the clinical utility of BCI within all RS risk groups. The estrogen signaling pathway biomarker H/I and proliferative biomarkers (MGI, grade, Ki67) were associated with restratification by BCI, while age, HER2 status, and tumor size were not.

Citation Format: Yan F, Master AK, Israel MA, Liu J, Schnabel CA, Hurvitz S, Gadi VK. Correlative analysis of breast cancer index (BCI) restratification of 21-gene recurrence score (RS) in patients with hormone receptor-positive (HR+), node-negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-06-10.

Abstract P4-09-09: Correlation of breast cancer index (BCI) predictive (HoxB13/IL17BR) results to nodal status and hormone receptor expression in early stage HR+ breast cancer

Background: The HoxB13/IL17BR (H/I) ratio, the endocrine response component of the Breast Cancer Index (BCI), was initially discovered in patients with LN- breast cancer, and validated as a predictive biomarker of benefit from extended endocrine therapy (EET) in a cohort from MA.17 that included both LN- and LN+ patients. Here, correlative analyses were performed to further characterize BCI Predictive (H/I) results with nodal status and quantitative hormone receptor expression.

Methods: Analyses were performed using data from the BCI Clinical Database for Correlative Studies, an IRB-approved de-identified database that contains >50 clinicopathologic and molecular variables from cases submitted for BCI in clinical practice (N=19,126). Clinicopathologic variables were abstracted from pathology reports, and were available for a subset of these cases. Cases from patients with confirmed nodal status were analyzed. Chi-squared tests and ANOVA were used to compare results between subgroups.

Results: Analyses included 13,114 patients (median age 58.9y; range 23-92y); 9562 were LN- and 3552 LN+. The distribution of individual H/I scores and proportion of patients classified as High H/I were generally similar in LN- and LN+ patients, though a modestly greater proportion of LN+ patients (46.2%) were classified as High H/I compared to LN- patients (42.0%; P<0.01). In both LN- and LN+ patients, median quantitative ER (qER) expression was slightly higher in patients with Low H/I than with High H/I; qPR showed the same trend but with a larger magnitude (P<0.0001 for both). Similar results were observed for percent positive staining by IHC (P<0.0001). In both LN- and LN+ patients, H/I showed a weak negative correlation with qER (LN-, 0.227; LN+, 0.192) and qPR expression (LN-, 0.311; LN+, 0.311).

Conclusion: In this study to evaluate potential biological correlates of BCI, results showed that H/I biomarker activity did not appear to be dependent on nodal status. Secondly, although ER expression is an established biomarker for endocrine sensitivity, High H/I status did not correlate with increased quantitative ER and PR expression. The H/I ratio may be an independent new marker for endocrine sensitivity independent of the strength of ER expression.

Citation Format: Elias A, Israel MA, Zhang Y, Schnabel CA, Mayordomo J. Correlation of breast cancer index (BCI) predictive (HoxB13/IL17BR) results to nodal status and hormone receptor expression in early stage HR+ breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-09-09.

Abstract P1-07-18: Clinicopathologic and molecular correlates of breast cancer index (BCI) results in patients with HR+, LN- breast cancer that are high risk of late distant recurrence (DR) / low likelihood of benefit from extended endocrine therapy (EET)

Background: BCI is a gene expression assay for patients with early stage HR+ breast cancer that provides 2 results: BCI Predictive, based on the HoxB13/IL17BR (H/I) ratio, reports a prediction of high vs low likelihood of benefit from EET; BCI Prognostic, based on the algorithmic combination of H/I and a set of proliferation-based genes, reports the risk of late distant recurrence (DR). Clinical actionability is distinct based on the 4 possible combinations of prognostic and predictive results. To better characterize patients classified by BCI as having a high risk of late DR but a low likelihood of benefit from EET, we assessed clinicopathologic and molecular correlates in this subset.

Methods: The BCI Clinical Database for Correlative Studies is a de-identified database containing >50 clinicopathologic and molecular variables from cases submitted for BCI in clinical practice (N=19,126). Clinicopathologic variables abstracted from pathology reports were available for a subset of these cases. Molecular proliferation status (molecular grade index [MGI]) and clinicopathologic parameters were examined in the 4 possible BCI result categories of BCI Prognostic (High vs Low risk) and BCI Predictive (High vs Low H/I). Chi-squared tests and ANOVA were used to compare BCI results within subsets.

Results: Analyses included 3843 LN- pts with clinicopathologic data: Median age was 59.1y (range 26-89y; 74% ≥50y); 30.9%, 51.7%, and 17.4% were Grade 1, 2, and 3, respectively; 27.8%, 48.9%, 21.7%, and 1.6% were T1a/b, T1c, T2, and T3, respectively. BCI categorized 41.4% of pts as having Low risk/Low likelihood of benefit, 31.3% with High risk/High benefit, 18.0% with High risk/Low benefit, and 9.3% with Low risk/High benefit. Patients with High Risk/Low Benefit had increased median proliferation scores (MGI), and a greater proportion of pts with grade 2/3 tumors and high Ki67 scores compared to pts with Low Risk/Low Benefit (P<.0001 for all). In contrast, there were only modest differences in clinicopathologic parameters between patients with High Risk/ Low Benefit and those with High Risk/High Benefit.

Conclusion: In characterizing the molecular and clinical correlates in BCI cases with a high risk of late DR but low likelihood of benefit from EET, we found that higher proliferative status was associated with classification of high risk of DR. Future studies might investigate whether patients with this molecular pattern might benefit from combinatorial therapy (e.g., CDK 4/6 inhibitors) with EET. This study highlights the importance of predictive biomarkers for individualized EET therapy recommendation.

Citation Format: Royce M, Poage G, Israel MA, Schnabel CA, Holmes FA. Clinicopathologic and molecular correlates of breast cancer index (BCI) results in patients with HR+, LN- breast cancer that are high risk of late distant recurrence (DR) / low likelihood of benefit from extended endocrine therapy (EET) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-18.

Abstract P1-06-09: Correlation of breast cancer index (BCI) results to lymphovascular invasion in early stage HR+ breast cancer

Background: Positive lymphovascular invasion (LVI) is a negative prognostic factor for women with early-stage ER+ breast cancer. LVI, along with other clinicopathologic factors such as larger tumor size, higher grade and positive nodal status, increase a patient's risk of late (post-5y) recurrence. Breast Cancer Index (BCI) is a validated gene expression-based assay for patients with early-stage HR+ breast cancer that reports an individualized risk of late distant recurrence based on a combination of the HOXB13/I17BR ratio and the molecular grade index (MGI). The correlation of LVI and individualized risk stratification by genomic analysis is not well characterized. Therefore, this study evaluated risk stratification by BCI based on the presence or absence of LVI.

Methods: A population of 2,613 patients with known LVI status were identified in the Breast Cancer Index Clinical Database for Correlative Studies, an IRB-approved de-identified database which contains clinicopathologic and molecular variables of more than 19,000 clinical cases submitted for BCI testing. LVI was recorded as either positive or negative based on pathology report review. BCI results based on LVI status from LN- (n=2035) and LN+ patients (n=578) were evaluated separately. Chi-squared tests were used to compare BCI results between LVI groups.

Results: In analyses of 2,613 patients with LVI data available (median age 59.1 y; range 28-89y; 74% ≥50y), 18.3% of patients showed evidence of LVI (LVI-pos). In comparison to the LVI-neg tumors submitted for BCI testing, the LVI-pos tumors had a higher proportion of grade 3 tumors (33% vs 16%, p<0.0001), more LVI-pos tumors were 2.0 cm or greater (45% vs 23%, p<0.0001), a higher percentage LVI-pos patients had node-positive disease (51% vs 16%, p<0.0001), and a higher proportion of LVI-pos tumors showed high Ki67 (Ki67 ≥14%; 64% vs 51%, p=0.004). A correlation between LVI positivity and high BCI prognostic risk was observed, with a higher proportion of LVI-pos patients classified as high risk of late distant recurrence in both the LN- (68% vs 49%, p<0.0001) and LN+ subsets (84% vs 70%, p<0.0001) compared to LVI-neg patients. LVI-pos patients had a higher median molecular proliferative status (MGI) compared to LVI-neg patients regardless of nodal status (p<0.0001 for both). In contrast to the categorical LVI prognostic factor, the wide distribution of BCI individual risk scores provides additional resolution that identifies a substantial subset of LVI positive tumors (32%) that that have a low risk of late recurrence by genomic analysis.

Conclusion: While BCI Prognostic stratification correlated with LVI status, BCI identified a subset of patients with LVI positivity as having a low risk of late distant recurrence that otherwise would have an unfavorable prognosis based on LVI and/or LN positivity. These findings help to characterize differential patient stratification based on an individualized assessment of tumor biology versus LVI for patients considering EET.

Citation Format: Vulchi M, Sagalnik M, Schnabel CA, Abraham J. Correlation of breast cancer index (BCI) results to lymphovascular invasion in early stage HR+ breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-06-09.

Abstract P1-07-12: Correlation of breast cancer index (BCI) prognostic and predictive results to clinicopathologic risk groups in early stage HR+ breast cancer

Background: Both clinicopathologic factors and genomic tests have been shown to be prognostic for risk of late distant recurrence (DR); however, few studies have characterized differential patient stratification.Breast Cancer Index (BCI) is a validated gene expression assay for patients with early-stage HR+ breast cancer that provides a prognostic result for high vs low risk of late distant recurrence and a separate predictive result (based on the HoxB13/IL17BR [H/I] ratio) for high vs low likelihood of benefit from extended endocrine therapy. Thus four categories of results are possible based on a patient's tumor biology. To better understand how patient stratification is affected by a combination of clinicopathologic and genomic factors, this study examined BCI assay results within clinicopathologic risk categories based on tumor size and grade.

Methods: This study utilized data from the BCI Clinical Database for Correlative Studies, an IRB-approved de-identified database which contains clinicopathologic and molecular variables from 19,126 clinical cases submitted for BCI testing. Clinicopathologic variables, abstracted from pathology reports, were available for a subset of these cases. This analysis evaluated cases from LN- patients with available clinicopathologic data. Chi-squared tests were used to compare BCI results between tumor size and grade subgroups.

Results: Analyses included 3843 LN- patients (median age 59.1y; range 26-89y; 74% ≥50y), of which 31%, 52%, 17% were Grade 1, 2, and 3, respectively, and 5%, 22.7%, 48.9%, 21.7%, and 1.6% were T1mi/a, T1b, T1c, T2, and T3, respectively. In analysis based on tumor size, there was a wide distribution of individual BCI Prognostic scores in all tumor size subsets; however, the proportion of patients classified as high risk increased with larger tumor size (T1a/b 39.0%, T1c 50.1%, T2 61.0%; p<.0001). In contrast, BCI Predictive (H/I) was not as strongly correlated with size, with a modestly larger proportion of patients classified as High H/I with larger tumor size (T1a/b 37.2%, T1c 40.5%, and T2 45.3%; p=.005). Within each tumor size category, the proportion of patients classified as BCI High Risk and High H/I increased with tumor grade (p<.0001). However, there was a wide distribution of individual risk assessments by BCI Prognostic and stratification by BCI Predictive (H/I) in all size + grade subsets. In patients with the most favorable clinicopathologic risk profile (T1a/b, G1), BCI classified 20% as high risk, 68% of whom also had High H/I.

Conclusion: While BCI results correlated with tumor size and grade, BCI identified substantial proportions of patients with favorable clinicopathologic features as high risk for late DR and apparent high likelihood of benefit from EET; conversely, BCI also identified patients with high risk clinicopathologic features as low risk for late distant recurrence and apparent low likelihood of benefit from EET. These findings help to differentiate between genomic-based and clinicopathologic-based risk/benefit assessment for patients considering EET.

Citation Format: Mayordomo J, Falkson C, Kepes J, Israel MA, Schroeder BE, Schnabel CA, Elias A. Correlation of breast cancer index (BCI) prognostic and predictive results to clinicopathologic risk groups in early stage HR+ breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-12.

Relevant bleeding diathesis due to acquired factor XIII deficiency

Acquired factor XIII (FXIII) deficiency is associated with reduced clot firmness and increased bleeding in patients undergoing major surgery. In contrast, only limited information is available on the haemostatic relevance of acquired FXIII deficiency in non-surgical patients.

An 81-year-old patient, who had experienced acute type-A dissection of the aorta eight years earlier, presented with a 3-year history of progressive mucocutaneous and softtissue bleeding. Diagnostic work-up was unremarkable for global coagulation tests, but FXIII and alpha2-antiplasmin were decreased to 33% and 27%, respectively, while plasma D-dimer was elevated to > 35 mg/l. A FXIII inhibitor was excluded by mixing studies. CT scanning revealed a massively elongated and progressively dilated aorta with a false lumen reaching from the left carotid artery to the iliac bifurcation. Bleeding control was achieved by single doses of FXIII at 20-30 IU/ kg body weight and tailored oral tranexamic acid.

Acquired FXIII deficiency with activity levels of 30–35% may confer a severe bleeding tendency in non-surgical patients, especially in the context of increased thrombin an fibrin generation.

Abstract S6-05: Comprehensive comparison of prognostic signatures for breast cancer in TransATAC

Background: A number of prognostic signatures have been developed for the prediction of breast cancer recurrence in the past decade. We have developed two signatures (Clinical Treatment Score (CTS), four immunohistochemical markers (IHC4)) and validated four prognostic signatures (Oncotype Dx Recurrence Score (RS), PAM50-based Prosigna (ROR), Breast Cancer Index (BCI), and EndoPredict (EPclin)) in the TransATAC cohort. Here, we compare the prognostic performance of these six signatures for distant recurrence (DR) in years 0-10, and specifically in years 5-10 after treatment cessation.

Methods: 1231 postmenopausal women with hormone receptor positive and HER2-negative breast cancer had at least one test performed. Of these, 818 women had data on all six signatures available. IHC4, RS and BCI (linear) are molecular only signatures whereas CTS, ROR and EPclin include clinicopathological factors. The primary endpoint was DR and the primary objective was to compare the prognostic value of the six signatures in terms of DR for years 0-10, 0-5, and 5-10. Secondary objectives included the comparison of the prognostic performance for node-negative and node-positive patients separately and the additional prognostic performance of each signature to the others. Likelihood ratio statistics (LR-χ2) were used to assess the prognostic information of each signature alone or in combination with other signatures.

Results: Median follow-up for this analysis was 9.94 years (IQR 8.01-10.09) and a total of 126 DR were recorded. 818 women with HER2-negative disease for whom data of all six signatures were available were included in this analysis. For all patients, CTS and EPclin were the most prognostic signatures in years 0-10 (CTS: LR-χ2=124.9; EPclin: LR-χ2=116.2) and years 5-10 (CTS: LR-χ2=59.6; EPclin: LR-χ2=56.8) in the univariate analysis. The other four signatures performed similarly well in years 0-5, but of those only BCI and ROR provided substantial prognostic information in years 5-10 (BCI: LR-χ2=25.3; ROR: LR-χ2=43.8). In multivariate analyses comparing the added information of the molecular signatures over CTS, IHC4 and BCI provided the most information (IHC4: ΔLR-χ2=19.0; BCI: ΔLR-χ2=19.8). In node-negative patients (72.3%), the ROR showed the most prognostic value in years 0-10 (LR-χ2=48.6) and years 5-10 (LR-χ2=31.3) whereas the RS was least prognostic in this patient group. For patients with node-positive disease (27.7%), the CTS and EPclin were the most prognostic and the other four signatures provided much less prognostic information for this patient population (data not shown).

Conclusion: Overall, the CTS and EPclin were the most prognostic signatures for DR and also added significant prognostic value to the other scores in women with HER2-negative disease, primarily due to the incorporation of nodal status in these signatures. For women with node-negative disease, the ROR, BCI, and EPclin signatures provided most prognostic value whereas for those with positive nodes CTS and EPclin were most prognostic. Our analyses showed that the inclusion of clinic-pathological factors into gene signatures is highly important for deriving an accurate prognostic assessment, particularly in node-positive patients.

Citation Format: Sestak I, Buus R, Cuzick J, Dubsky P, Kronenwett R, Ferree S, Sgroi D, Schnabel C, Baehner R, Mallon E, Dowsett M. Comprehensive comparison of prognostic signatures for breast cancer in TransATAC [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr S6-05.

Abstract P2-05-18: Correlation of breast cancer index (BCI) risk classification with tumor grade and Ki-67 in a large series of patients with early-stage, ER+ breast cancer

Background: Breast Cancer Index (BCI) is a gene expression-based test that integrates biomarker panels of both proliferation (molecular grade index, MGI), and endocrine response (HoxB13/IL17BR). BCI has been validated as a significant and independent prognostic factor both for risk of overall (0-10y) and late (>5y) distant recurrence, and is predictive of extended endocrine benefit in patients with early-stage, ER+ breast cancer. In this study, correlative analyses of risk stratification by BCI and MGI versus tumor grade or Ki67 were assessed to characterize their relationship to other markers of proliferation.

Methods: Retrospective analysis of consecutive cases (N=1359) from node negative early-stage breast cancer patients submitted for clinical testing with BCI were analyzed. Median age at diagnosis was 58 years, 57% and 6% were HER2 negative and positive, respectively, with 37% unknown status. Tumor grade and Ki67 information was abstracted from pathology reports, and was available for 1335 and 372 cases, respectively. 29%, 52% and 17% of patients had grade 1, 2 and 3 tumors, respectively, with 2% having unknown grade. Tumor sizes were 26% (≤ 1cm), 48% (>1 - ≤ 2cm), 23% (>2 - ≤ 5cm), 2% (≥ 5cm) and 1% were unknown. Ki67 categories were based on 10% and 20% IHC expression levels into low, intermediate and high groups. Statistical methods included Pearson correlation between BCI/MGI versus Ki67 as continuous variables & coefficient of determination derived from the analysis of variance (ANOVA) model between continuous BCI/MGI versus tumor grade. Chi-square test assessed the significance of concordance between BCI, MGI risk groups to tumor grade and Ki67 groups.

Results: As continuous variables, BCI and MGI correlated weakly with tumor grade (coefficient of determination= 0.26 and 0.22, respectively) and Ki67 (r2 = 0.35 and 0.33, respectively). Although statistically significant concordance was demonstrated between BCI/tumor grade, MGI/tumor grade, BCI/Ki67, MGI/Ki67 categories (p<0.0001 for all, Tables 1 & 2), discordance between BCI versus tumor grade or Ki67 was 51% and 45%, respectively. In particular, BCI classified 4% of well differentiated tumors as high-risk and 18% of poorly differentiated tumors as low-risk. Similarly, BCI classified 4% of low Ki67 patients as high risk and 28% of high Ki67 patients as low risk.

Table 1: BCI risk classification vs tumor grade Grade 1Grade 2Grade 3BCI Low Risk30536542BCI Intermediate Risk6921656BCI High Risk15130137

Table 2: BCI risk classification vs Ki67 Ki67 LowKi67 IntermediateKi67 HighBCI Low Risk1094740BCI Intermediate Risk213645BCI High Risk6860

Conclusions: Data from this large retrospective analysis show that correlation of BCI and its mitogenic panel, MGI, to tumor grade and Ki67 are moderate to weak. These findings indicate that BCI and MGI are capturing distinct information related to tumor proliferative status compared with tumor grade and Ki67.

Citation Format: Soliman H, Schroeder BE, Zhang Y, Magliocco AM, Schnabel CA. Correlation of breast cancer index (BCI) risk classification with tumor grade and Ki-67 in a large series of patients with early-stage, ER+ breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-18.

Abstract P2-05-14: Prognostic impact of genomic risk stratification with breast cancer index in patients with clinically low risk, hormone receptor-positive, node-negative, T1 breast cancer

Background: Tumor size and nodal status are prognostic for risk of both early and late disease recurrence in patients with early stage, HR+ breast cancer, and are incorporated into both adjuvant chemotherapy and extended endocrine therapy treatment decisions. In a recent EBCTCG meta-analysis of over 46,000 patients [Pan H, et al. J Clin Oncol 34, 2016 (suppl; abstr 505)], risk of late distant recurrence was assessed in patient subsets based on nodal status and tumor size. Patients with T1N0 disease who were treated with 5 years endocrine therapy had a good overall prognosis, with 4%, 9%, and 14% risk of distant recurrence from years 5-10, 5-15, and 5-20, respectively. Breast Cancer Index (BCI) has been validated as prognostic biomarker for risk of both early and late distant recurrence in multiple randomized trial cohorts. The aim of this analysis was to assess distant recurrence (DR) risk stratification with BCI in patients with clinically low-risk T1N0 tumors.

Methods: Primary tumor samples from the subset of patients with T1N0 disease from 2 independent validation cohorts of HR+ breast cancer patients were examined [Stockholm randomized controlled trial (N=259) and a retrospective multi-institutional cohort (N=237)]. Patients in the Stockholm RCT cohort were treated with adjuvant tamoxifen only; patients in the multi-institutional cohort were treated with adjuvant tamoxifen +/- chemotherapy (20.3%). No patients received extended endocrine therapy. Kaplan-Meier analysis was used to assess the risk of DR within distinct BCI risk groups. Time dependent analysis was performed by combining BCI Low and Intermediate risk groups for risk of early recurrence (0-5y), and BCI Intermediate and High risk groups for risk of late recurrence (>5y).

Results: In the Stockholm cohort, BCI identified 13% of T1N0 patients as high risk for relapse within the first 5y, and these patients had a significantly reduced distant recurrence-free survival (DRFS, 85.3%) compared to BCI Low Risk patients (97.7%; P=0.0004). In patients disease-free at year 5, BCI identified 32% of patients as high risk for late recurrence; these patients had significantly lower DRFS (86.7%) between years 5-15 compared to BCI low risk patients (95.4%; P=0.0263). In the multi-institutional cohort, 22% of T1N0 patients were identified by BCI as high risk for relapse within the first 5y, and these patients had a significantly reduced DRFS (77.3%) compared to BCI low risk patients (96.2%; P<0.0001). In patients disease-free at year 5, 36% of patients were identified by BCI as high risk for late recurrence, with significantly lower DRFS (89.6%) between years 5-10 compared to BCI Low Risk patients (98.4%; P=0.008).

Conclusions: HR+ Patients with favorable clinical features (T1N0) have a good overall prognosis. However, results of this study demonstrated that adding molecular resolution on tumor biology with BCI identified a significant subset of women with higher risk of both early and late distant recurrence; findings support consideration of genomic classification in T1N0 patients to identify additional candidates for adjuvant chemotherapy and/or extended endocrine therapy, respectively.

Citation Format: Schroeder BE, Zhang Y, Stal O, Fornander T, Brufsky A, Sgroi DC, Schnabel CA. Prognostic impact of genomic risk stratification with breast cancer index in patients with clinically low risk, hormone receptor-positive, node-negative, T1 breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-14.

Abstract P2-09-15: A multi-institutional, prospective study of incorporating the genomic platform breast cancer index as a tool for decision-making regarding extension of adjuvant endocrine therapy

Background: Extending adjuvant endocrine therapy (AET) for hormone responsive breast cancer (HRBC) from 5 to 10 years is beneficial for many in preventing late relapse. Current decision-making regarding extension relies on a decision-making process that weighs non-personalized recurrence risks against risks and benefits of extended AET. The Breast Cancer Index (BCI, BioTheranostics Inc) has been validated to quantify the risk of late recurrence and to predict likelihood of benefit from AET extension based on an individual's tumor genomic profile. The purpose of this study was to conduct a multi-institutional study to prospectively assess the impact of BCI i) on provider's recommendation using the BCI results; 2) the confidence with decision-making; and 3) patient's satisfaction regarding extension of AET.

Methods: Patients with stage I-III HRBC treated at Yale Cancer Center and University of Pittsburgh Medical Center (UPMC), who had completed at least 3.5 years of AET were eligible. BCI was performed on FFPE samples from the original tumor sample (bioTheranostics Inc.). Patients and physicians completed pre- and post-test questionnaires examining preferences for extending AET, patients also completed anxiety and decision-conflict surveys.

Results: 140 patients [mean age 61, 80% postmenopausal, 73% stage I] were included. No extended AET was recommended for 35.3% patients' pre-testing. Reasons physicians did not recommend extended AET were perceived low risk of recurrence (87%), risk of osteoporosis (25%) and side effects (13%). Extended therapy was recommended for 65.7% patients pre-testing. Integration of BCI resulted in a change in physician treatment recommendation in 29% of patients. The recommendation for no extended AET rose to 48% and recommendation for extended AET dropped to 52% (OR=1.76 95% CI 1.08-2.85; p=.003). Of the recommendations that changed (N=41), the majority (73%) was for not extending endocrine therapy. However, 27% of recommendations were to extend endocrine therapy because of high risk or high likelihood of benefit results. More physicians felt strongly confident in their recommendation after the test result (26.4%) than before (9.3%) (OR= 3.5 95% CI 1.77-6.95; p<.0001). Satisfaction of decision increased in 23% of patients (OR=2.72 95% CI 1.66-4.46; p<.0001). Patient reported concerns including the cost, safety and benefit of extended AET decreased from pre- to post-testing (p=.025; p<.0001; p=.0012 respectively)

Conclusions: Overall, incorporation of BCI into clinical practice resulted in significant changes in physician recommendations regarding AET duration, with the majority of recommendations for no extended AET. Physicians reported increased confidence for their recommendation when incorporating the test result. There was also a significant increase in patient satisfaction and decrease in patient reported concerns regarding cost, safety and benefit of extended AET. The BCI is a tool that could be incorporated into decision-making algorithms to enhance physician confidence and patient satisfaction with recommendations for extending AET.

Citation Format: Sanft T, Berkowitz A, Schroeder B, Hatzis C, Schnabel C, Aktas B, Brufsky A, Pusztai L, vanLonden GJ. A multi-institutional, prospective study of incorporating the genomic platform breast cancer index as a tool for decision-making regarding extension of adjuvant endocrine therapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-09-15.

Abstract P2-05-08: Impact of treatment history on prognostic ability of breast cancer index (BCI): Subset analysis from a validation study of patients with hormone receptor-positive (HR+) breast cancer with 1-3 positive nodes

Background: A new BCI model integrating tumor size and grade (BCIN+) was specifically developed and validated for prediction of risk of overall (0-15y) and late (5-15y) distant recurrence (DR) in HR+ women with 1-3 positive nodes (N1). The objective of this study was to evaluate the impact of treatment history on the prognostic performance of BCIN+ in a large clinical validation cohort of pre- and post-menopausal HR+, N1 patients.

Methods: The validation cohort was comprised of 402 HR+, N1 patients diagnosed at Massachusetts General Hospital between 1993-2007 with at least 5y of follow-up. BCIN+ risk scores were determined and patients stratified into low or high risk categories using a pre-specified cut-point blinded to clinical outcome. Kaplan-Meier estimates of overall (0-15y) and late (5-15y) DR were estimated and the difference was evaluated by log-rank test. Treatment-specific subsets were analyzed based on adjuvant endocrine (tamoxifen [TAM] only vs any history of aromatase inhibitors [AI]), and adjuvant chemotherapy treatment history.

Results: Mean age of patients was 53y. 99% were ER+, 91% PR+, and 13% HER2+. The majority of tumors were T1 (62%) or T2 (35%). Adjuvant endocrine treatment included TAM only for 191 (48%) patients and either AI only or a sequence of TAM and an AI in 211 (52%) patients. Most patients received chemotherapy (n=324; 81%). BCIN+ classified 20% and 80% as low and high risk, respectively.

In patients treated with TAM only, BCIN+ low and high risk had significantly different 15y rates of DR (95% CI) of 4.0% (0.0-11.4%) vs 41.7% (33.0-49.3%), respectively (p=0.0005). For patients disease-free at year 5, rates of late DR (5-15y) were 4.0% (0.0-11.5%) vs 20.0% (11.4-27.8%), respectively (p=0.04). In patients treated with an AI, BCIN+ low and high risk had significantly different 15y rates of DR of 0% (0.0-0.0%) vs 15.0% (8.1-21.5%), respectively (p=0.006). For patients disease-free at year 5, rates of late DR were 0.0% (0.0-0.0%) vs 12.2% (5.6-18.3%), respectively (p=0.02). There was no statistically significant difference in the prognostic performance of BCIN+ between patients treated with TAM only versus those with treatment including any history of AI (interaction p=0.99).

In the subset of patients treated with chemotherapy, BCIN+ classified 19% and 81% of patients as low and high risk with significantly different 15y rates of DR of 1.7% (0.0-4.9%) vs 30.9% (24.4-36.8%), respectively (p<0.0001). For patients disease-free at year 5, rates of late DR were 1.7% (0.0-4.9%) and 16.3% (10.2-21.9%), respectively (p=0.006).

Conclusions: In this subset analysis from a validation study of N1 patients, BCIN+ identified a significant proportion with a significantly low risk of late DR. This study confirms the ability of BCIN+ to identify a subset of patients with significantly low risk of recurrence across adjuvant endocrine and chemotherapy treatment backgrounds. BCIN+ may provide additional prognostic information to facilitate selection of N+ patients for extended endocrine treatment, wherein patients identified as BCIN+ low may be considered adequately treated with adjuvant therapy alone.

Citation Format: Zhang Y, Jerevall P-L, Schroeder BE, Ly A, Nolan H, Schnabel CA, Sgroi DC. Impact of treatment history on prognostic ability of breast cancer index (BCI): Subset analysis from a validation study of patients with hormone receptor-positive (HR+) breast cancer with 1-3 positive nodes [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-08.

Abstract P5-03-01: An optimized 92-gene assay for the molecular diagnosis of triple-negative breast cancer

Background: Triple negative breast cancer (TNBC) often presents as high grade, poorly differentiated tumors resulting in a more aggressive disease for which accurate and timely diagnosis is critical to treatment selection or clinical trial enrollment. Furthermore, the high rate of distant metastases and absence of breast-specific immunohistochemical markers that contribute to diagnostic uncertainty may delay or limit treatment modalities that can lead to poorer outcomes. The 92-gene assay is an RT-PCR-based cancer classifier that previously demonstrated 80% accuracy for the diagnosis of breast cancer. In this study, blinded validation of an optimized algorithm and assay specifically developed to improve performance in TNBC is described.

Methods: To increase clinical scope for the diagnosis of TNBC, formalin fixed paraffin embedded specimens (N=103) representing a range of breast tumor histologies (e.g. TNBC, adenoid cystic, neuroendocrine, metaplastic, lobular, mucinous, DCIS) were added to the tumor reference database. A revised computational algorithm was constructed by the integration of machine learning techniques. For validation, tumor specimens (N=160) of TNBC (57%) and non-breast tumors (43%) were blindly tested using a 92-gene cancer classifier (CancerTYPE ID®, Biotheranostics, Inc). Tumor type predictions were reported as rank-order probabilities based on the degree of similarity to the tumor reference database. Assay sensitivity based on concordance of the main tumor type prediction with the reference diagnosis established by clinicopathologic review was analyzed.

Results: Assay results included 85 breast carcinomas (TNBC) (53%), 23 Salivary gland carcinomas (14%), and 52 carcinomas (33%) representing 11 other tumor types. For performance in TNBC, the 92-gene assay demonstrated an overall sensitivity of 93% (CI, 86-98), and sensitivities of 96% [95% CI, 89-99] and 80% [95% CI, 52-96], in primary and metastatic tumors, respectively (P=0.085). Additional performance characteristics are shown in Table 1.

Table 1Pathology subsetN, Validation setN, Correct 92-gene assay predictionsSensitivity (95% CI)All TNBC91850.93 (0.86-0.98)TNBC-primary76730.96 (0.89-0.99)TNBC-metastatic15120.80 (0.52-0.96)All Non-breast69550.80 (0.68-0.88)Salivary gland carcinoma25230.92 (0.74-0.99)Overall performance1601400.88 (0.81-0.92)

Conclusions: An optimized 92-gene assay specifically modified to increase performance for the molecular diagnosis of TNBC showed strong accuracy in this blinded study. These findings support use of the 92-gene cancer classifier to aid in the diagnosis of primary or metastatic TNBC. With more refined tumor characterization, TNBC-specific chemotherapy regimens or clinical trial therapies may be pursued with the potential for improved patient outcomes.

Citation Format: Sullivan PS, Soifer HS, Liu J, Zhang Y, Schnabel CA, Brachtel EF. An optimized 92-gene assay for the molecular diagnosis of triple-negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-03-01.

Abstract P4-11-03: The impact of extended endocrine therapy on symptom burden and health-related quality of life in patients with early-stage breast cancer

Background: Extended endocrine therapy (> 5 years; EET) is recommended for many ESBC patients following the results of the MA.17, ATLAS, and aTTom clinical trials. Clinical practice guidelines recommend consideration of 10 years of endocrine therapy; however, they note the challenging risk vs benefit profile given the modest benefit of EET in terms of preventing disease recurrence (∼3-5%) and the potential for adverse effects and tolerability challenges. Studies examining the long-term impact of EET are lacking. The objective of this study was to assess the impact of EET in ESBC patients on symptom burden and health-related quality of life (HRQoL).

Methods: Retrospective review of existing medical records for patients (N=308) with ER+ ESBC. Eligible patients had completed 5 years of adjuvant endocrine therapy without disease progression, minimum of 1 year additional follow-up, and at least one Patient Care Monitor (PCM) survey, a validated 86-item, patient reported outcomes measure that assesses symptoms common in patients undergoing cancer treatment, during the 1 to 3 year follow-up period. Primary analysis included 6 PCM index scores and 12 PCM items representing symptoms of particular interest. Patients were classified as having received EET (minimum 8 months) vs. Control (no extended therapy). Linear mixed models were employed to examine differences in symptom burden between EET and Control groups during the 3-year follow-up period, including differences in change over time across groups, and whether patterns of symptoms lead to discontinuation of EET.

Results: This analysis included 156 EET and 152 Control patients [75.0% Caucasian, 22.7% African American, with mean age of 61 (±11) years, and predominantly from the Southern US (93.8%)]. The sample was 40.9% Stage I at diagnosis, 48.4% stage II, and 10.1% stage III. EET patients were younger (59 vs. 63 years, p = .0008), and more likely to have stage III disease (p =<.0001). Results from preliminary interim analyses indicate that EET vs no EET was associated with statistically significant differences in symptom burden in certain PCM items (eg, increased vaginal dryness, reduced sexual enjoyment). Final analyses will be available on Sept 1st and the abstract will be updated at that time.

Conclusions: Based on interim analyses from this study, EET may be associated with continued symptom burden and impact on HRQoL. These results suggest that the decision whether to extend endocrine therapy in patients with ESBC should be multi-faceted, including discussion of the potential benefit of extended therapy, risk of ongoing/worse symptomatology, and long-term impact on patients QoL.

Citation Format: Fisher MD, Schroeder BE, Miller PJ, Schnabel CA, Schwartzberg L, Walker MS. The impact of extended endocrine therapy on symptom burden and health-related quality of life in patients with early-stage breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-11-03.

Abstract P5-08-09: Differential patient stratification by the breast cancer index HoxB13/IL17BR ratio vs recurrence score (RS) plus quantitative ER expression in hormone receptor positive, node negative breast cancer

Background: Second generation genomic biomarkers for patients with early stage breast cancer are based on integration of proliferative and estrogen signaling-related gene expression, which has led to data applicable in the extended (post-5 year) endocrine therapy setting. The Breast Cancer Index (BCI) assay interrogates these two signaling pathways, significantly stratified patients into high (13.4%) or low (3.5%) risk of late (5-10y) distant recurrence in TransATAC , and includes a gene expression signature (HoxB13/IL17BR, H/I) that predicted benefit from extended endocrine therapy in MA.17. The 21-gene assay has recently been investigated in combination with quantitative estrogen receptor (qER) expression, wherein a subset of approximately 20% of patients with a high recurrence score (RS) and qER above 9.1 had a higher prognostic risk for late distant recurrence (12.6%) than those with Low RS (4.7%) or intermediate RS (4.1%) (Wolmark, ASCO 2014). The objective of this study was to compare patient stratification with H/I and RS+qER.

Methods: Consecutive cases submitted for BCI clinical testing from lymph node-negative breast cancer patients with available RS scores and qER >9.1 abstracted from pathology reports (N=115) were analyzed. Cohen's kappa statistic was used to test agreement between H/I and RS+qER for patient stratification.

Results: No statistically significant agreement was observed between H/I stratification and RS+qER prognostic risk stratification with respect to identifying patients for extended endocrine therapy (Cohen's kappa = -0.002, p = 0.51). H/I identified 36 cases (34%) as High likelihood to benefit from extended endocrine therapy compared to 3 cases (3%) classified as by RS+qER as having high risk of late recurrence (Table). Of the 69 cases (66%) classified as RS+qER Low risk, 19 were identified as High likelihood to benefit from extended endocrine therapy by H/I.

Table Low H/I PredictiveHigh H/I PredictiveTotalRS+qER Low Risk50 (48%)19 (18%)69 (66%)RS+qER Inter Risk17 (16%)16 (15%)33 (31%)RS+qER High Risk2 (2%)1 (1%)3 (3%)Total69 (66%)36 (34%) 

Conclusions: This retrospective analysis of clinical cases shows that H/I and RS+qER identify distinct subsets of patients, and highlights that the underlying biology of risk stratification differs from that of endocrine responsiveness. Comparatively, findings indicate that the H/I identifies additional patients that may be considered for extended endocrine therapy.

Citation Format: Naughton MJ, Schroeder BE, Operana TN, Zhang Y, Schnabel CA. Differential patient stratification by the breast cancer index HoxB13/IL17BR ratio vs recurrence score (RS) plus quantitative ER expression in hormone receptor positive, node negative breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-09.

Abstract P5-08-03: Prognostic impact of the combined risk groups by breast cancer index and HOXB13/IL17BR ratio in hormonal receptor positive, node negative breast cancer: A TransATAC study

Background: Breast Cancer Index (BCI) is a gene expression-based assay that reports two distinct results: 1) BCI predictive based on HoxB13/IL17BR ratio (H/I), and 2) BCI prognostic based on an algorithm incorporating H/I with the Molecular Grade index (MGI). Both biomarkers have been validated independently in randomized trial cohorts. However, integrated results to better correlate recurrence risk with endocrine response have not been evaluated. The aim of this post-hoc analysis was to examine patient outcomes within BCI prognostic and predictive groups using the translational arm of the Arimidex, Tamoxifen, Alone or in Combination trial (TransATAC).

Methods: Primary tumor samples (N=742) from hormonal receptor-positive, N0 breast cancer patients treated with 5 years of tamoxifen (TAM) or anastrozole (ANA) in the ATAC trial were examined. Kaplan-Meier analysis was used to examine the risk of distant recurrence (DR) in patient subgroups derived from BCI and H/I results. A separate series of clinical cases submitted for BCI testing (N=853) were analyzed to determine distribution of the combined BCI and H/I groups in clinical practice.

Results: Summary of patient distribution across the 6 BCI clinical subgroups showed that a large number of patients (331/742, 45%) were BCI low risk with low likelihood of benefit, whereas 108/742 (15%) of patients with endocrine responsive disease (High H/I) were classified as BCI low risk (Table 1). Kaplan-Meier analysis demonstrated that patients classified as BCI low risk had a very similar 10-year risk of DR irrespective of H/I status (H/I low: 5.5% vs. H/I high: 4.0%), indicating that prognosis was largely determined by BCI vs H/I.

Table 1: Distribution of BCI and H/I risk groups in TransATAC BCI: PrognosticH/I: PredictiveLow RiskIntermediate RiskHigh RiskTotalLow Likelihood3318717435 (59%)High Likelihood10895104307 (41%)Total439 (59%)182 (25%)121 (16%)742

In 853 node negative cases submitted for BCI clinical testing, the distribution of BCI and H/I risk groups were similar to that from the TransATAC cohort (Table 2).

Table 2: Distribution of BCI and H/I risk groups in clinical cases submitted for BCI testing BCI: PrognosticH/I: PredictiveLow RiskIntermediate RiskHigh RiskTotalLow Likelihood36410523492 (58%)High Likelihood96107158361 (42%)Total460 (54%)212 (25%)181 (21%)853

Discussion: Both prognostic and predictive components reported from the BCI assay may be used to stratify patients into 6 clinical subgroups based on prognostic risk of distant recurrence and endocrine responsiveness. Findings from this analysis indicate that patients classified as BCI low risk, regardless of H/I status, had sufficiently low DR rates and identifies patients that may be adequately treated with 5 years of endocrine therapy.

Citation Format: Zhang Y, Sestak I, Schroeder BE, Dowsett M, Cuzick J, Schnabel CA, Sgroi DC. Prognostic impact of the combined risk groups by breast cancer index and HOXB13/IL17BR ratio in hormonal receptor positive, node negative breast cancer: A TransATAC study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-03.

Abstract P6-07-11: Health economic impact of breast cancer index (BCI) for late disease management in patients with estrogen receptor-positive, node-negative breast cancer

Background

Several recent randomized, prospective clinical trials (MA.17, ATLAS, aTTom) have demonstrated the clinical benefit of extending endocrine therapy beyond 5 years to address the persistent risk of recurrence in patients with ER+ breast cancer. Breast Cancer Index (BCI) is a gene expression-based test that predicts overall (10y) risk of recurrence in patients with ER+, LN- breast cancer, and also informs late (post-5 year) disease management by providing information on risk of late (≥5y) recurrence, and likelihood of benefit from extended (≥5y) endocrine therapy. Previously, BCI was shown to be cost saving across a 10-year disease horizon. The current study specifically assessed the health economic benefit of BCI for late disease management, evaluating the impact of identifying patients at risk of late recurrence and those that may benefit from extended endocrine therapy.

Methods

A fact-based economic model was developed which projected the cost and effectiveness of BCI from a US third-party payer perspective in a hypothetical population of patients with ER+, LN- breast cancer who are disease free at 5 years post-diagnosis compared to standard clinical practice. Patients flowed through the model based on patterns of care and BCI data. Costs associated with endocrine therapy, toxicity, follow-up, and recurrence were modeled over 5 yrs. Model inputs were based primarily on published literature, and supplemented by interviews with disease experts and payers. Sensitivity analyses were performed around key inputs to estimate effects on the model.

Results

Use of BCI is projected to be cost saving in this population of patients that are disease-free at 5 years post-diagnosis, with a net cost savings of $691 per patient tested after accounting for BCI cost. Gross cost savings were projected to be achieved through reduced recurrence in patients receiving extended endocrine therapy based on BCI ($4,102), and reduced recurrence in previously non-compliant patients ($39). BCI was cost saving for both pre- and post-menopausal women. Sensitivity analyses demonstrated that results were most sensitive to current use of extended endocrine therapy in postmenopausal patients, future use of extended endocrine therapy in BCI (H/I) high patients, and the percentage of patients characterized as BCI (H/I) high.

Conclusions

BCI is projected to be cost saving in a population of ER+, LN-, breast cancer patients who are recurrence free at 5 years post-diagnosis. Cost savings are achieved through projected impact on extended endocrine therapy use and endocrine therapy compliance, and provide additional cost savings beyond impact on chemotherapy utilization. These findings require validation in additional cohorts, including studies of real-world clinical practice.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-07-11.

Relevant bleeding diathesis due to acquired factor XIII deficiency

BACKGROUND

Acquired factor XIII (FXIII) deficiency is associated with reduced clot firmness and increased bleeding in patients undergoing major surgery. In contrast, only limited information is available on the haemostatic relevance of acquired FXIII deficiency in non-surgical patients.

CASE REPORT

An 81-year-old patient, who had experienced acute type-A dissection of the aorta eight years earlier, presented with a 3-year history of progressive mucocutaneous and soft-tissue bleeding. Diagnostic work-up was unremarkable for global coagulation tests, but FXIII and alpha2-antiplasmin were decreased to 33% and 27%, respectively, while plasma D-dimer was elevated to > 35 mg/l. A FXIII inhibitor was excluded by mixing studies. CT scanning revealed a massively elongated and progressively dilated aorta with a false lumen reaching from the left carotid artery to the iliac bifurcation. Bleeding control was achieved by single doses of FXIII at 20-30 IU/kg body weight and tailored oral tranexamic acid.

CONCLUSION

Acquired FXIII deficiency with activity levels of 30-35% may confer a severe bleeding tendency in non-surgical patients, especially in the context of increased thrombin an fibrin generation.

Abstract P2-10-15: Evaluation of Prognostic and Predictive Performance of Breast Cancer Index and Its Components in Hormonal Receptor-Positive Breast Cancer Patients: A TransATAC Study

Background: The Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial compared the efficacy and safety of 5 years of anastrozole with tamoxifen as adjuvant treatment for postmenopausal women with localized HR+ breast cancer. At a median follow-up of 10 years, a statistically significant improvement with anastrozole vs. tamoxifen for disease-free survival, time to recurrence and time to distant recurrence was observed. The HOXB13:IL17BR gene expression ratio (H/I) quantifies recurrence risk in ER positive (ER+) breast cancer patients and is predictive of benefit from endocrine therapy. Molecular Grade Index (MGI) is a five-gene index that provides quantitative and objective molecular assessment of tumor grade and proliferative status. Breast Cancer Index (BCI) combines H/I and MGI into a continuous risk model that provides a likelihood of distant recurrence in patients treated with endocrine therapy, and efficacy from neoadjuvant chemotherapy. In the current analysis, evaluation of the prognostic and predictive performance of BCI, H/I and MGI in the ATAC study cohort was conducted.

Methods: Under the TransATAC protocol, formalin-fixed, paraffin-embedded (FFPE) blocks of primary tumor were collected from HR+ patients from each monotherapy arm. The current study examined samples collected from the United Kingdom, which constituted 79% of the collection. RNA extracted from 1102 samples from the TransATAC study was amplified, converted to cDNA and subjected to RT-PCR with primers and probes to HOXB13, IL17BR, BUB1A, CENPA, NEK2, RACGAP1 and RRM2. H/I, MGI and BCI were calculated and risk groups were determined using pre-specified cutpoints.

Results: Of 1102 tumor specimens assayed, 29 failed QC criteria, leaving 1073 samples for analysis. Detailed results on the prognostic and predictive performance of BCI, H/I and MGI will be presented. Data on whether BCI and its components provided independent prognostic information in the presence of classical variables, their prognostic value for risk of late recurrence, interaction by treatment arms, and comparative performance vs other models will also be discussed.

Discussion: The ATAC trial has established the long-term efficacy and safety of anastrozole over tamoxifen as initial adjuvant treatment for post-menopausal early stage breast cancer patients. Continued efforts are needed to improve on quantification of residual risk in patients who were treated with endocrine therapy to guide decision-making in selecting additional adjuvant chemotherapy and/or administering extended endocrine treatment. This study will help to establish the strategy to more effectively select patients for adjuvant therapies.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-15.

Abstract P1-07-13: Prognostic relevance of statistically standardized estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) in tamoxifen(TAM)-treated NCIC CTG MA.14 patients

Background: Poor inter-laboratory comparability of common clinically used breast cancer biomarkers led to a proposal of statistical standardization (SS) of laboratory results, similar to bone mineral density (BMD) z-scores. This analysis is the first utilization of SS in a trial where all women received TAM.

Methods: MA.14 allocated 667 postmenopausal women to TAM +/− Octreotide LAR (OCT) based on locally determined ER/PR, without HER2 status. At 9.8 yrs median follow-up, the secondary endpoint of relapse-free survival (RFS) had a non-significant hazard ratio (HR) for TAM-OCT to TAM of 0.87 (95% CI 0.63–1.21; p = 0.40). 299 patients who were representative of MA.14 patients by treatment and stratification factors (exact Fisher p-values=0.19–0.90) had their tumors centrally assessed for ER, PR, and HER2 by RT-PCR. Continuous values were used for SS of each biomarker. Univariate (uni) assessment used similar categorizations as those for BMD, assigning ER/PR/HER2 values by number of standard deviations (SD) about the mean (Group 1, z-score ≥1.0 SD below mean; Group 2, z-score <1.0 SD below mean; Group 3, z-score ≤1.0 SD above mean; Group 4, z-score >1.0 SD above mean). A log-rank statistic was used to test for differences between SS biomarker groups with K-M plots for graphical description. Multivariate (multi) effects of SS biomarkers and baseline patient characteristics on RFS were examined with exploratory (un)stratified Cox step-wise forward regression, adding a factor if likelihood ratio criterion was p ≤ 0.05. Sensitivity analyses used a prior external HER2+ cut-point of ≥1.32 SD.

Results: 292 patient samples passing internal analytical quality control were included in this analysis. Uni analyses indicated SS ER was not associated with RFS (p = 0.31). SS PR had a significant uni effect on RFS [p = 0.03; Group 4 compared to Group 1, HR of 0.33 (95% CI 0.12–0.90); Group 3 compared to Group 1, HR of 0.42 (95% CI 0.21–0.83); and Group 2 compared to Group 1 HR of 0.70 (95%CI 0.36–1.37)]. SS HER2 also had a significant uni effect on RFS [p = 0.004; Group 4 compared to Group 1, HR of 0.90 (95% CI 0.37–2.16)]; Group 3 compared to Group 1, HR of 0.39 (95% CI 0.18–0.84); and, Group 2 compared to Group 1, HR of 0.34 (95% CI 0.16–0.70)]. Multi stratified/unstratified Cox models indicated T1 tumours (p = 0.02/p = 0.0002) and higher SS PR (p = 0.02/0.01) were associated with significantly longer RFS; other unstratified results showed that N-ve patients had better RFS (p < .0001), while local ER/PR status did not impact RFS (p > 0.05). The HER2+ cut-point of ≥1.32 SD indicated directionally worse RFS (uni p-value=0.05; multi p-value=0.06).

Discussion: In MA.14, all women received TAM. Local ER/PR status using categorical or semi-quantitative values did not impact RFS. A statistically standardized approach using continuous centralized ER, PR, HER2 by RT-PCR demonstrated that increasing PR values were associated with better RFS. Evaluation in other trials may provide support for this methodology.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-07-13.

Breast Cancer Index predicts pathological complete response and eligibility for breast conserving surgery in breast cancer patients treated with neoadjuvant chemotherapy

BACKGROUND

The aim of neoadjuvant chemotherapy is to increase the likelihood of successful breast conservation surgery (BCS). Accurate identification of BCS candidates is a diagnostic challenge. Breast Cancer Index (BCI) predicts recurrence risk in estrogen receptor+lymph node-breast cancer. Performance of BCI to predict chemosensitivity based on pathological complete response (pCR) and BCS was assessed.

METHODS

Real-time RT-PCR BCI assay was conducted using tumor samples from 150 breast cancer patients treated with neoadjuvant chemotherapy. Logistical regression and c-index were used to assess predictive strength and additive accuracy of BCI beyond clinicopathologic factors.

RESULTS

BCI classified 42% of patients as low, 35% as intermediate and 23% as high risk. Low BCI risk group had 98.4% negative predictive value (NPV) for pCR and 86% NPV for BCS. High versus low BCI group had a 34 and 5.8 greater likelihood of achieving pCR and BCS, respectively (P=0.0055; P=0.0022). BCI increased c-index for pCR (0.875-0.924; P=0.017) and BCS prediction (0.788-0.843; P=0.027) beyond clinicopathologic factors.

CONCLUSIONS

BCI significantly predicted pCR and BCS beyond clinicopathologic factors. High NPVs indicate that BCI could be a useful tool to identify breast cancer patients who are not eligible for neoadjuvant chemotherapy. These results suggest that BCI could be used to assess both chemosensitivity and eligibility for BCS.

P5-13-08: Breast Cancer Index Predicts Likelihood of Breast Conservation Surgery after Neoadjuvant Chemotherapy

Introduction: Neoadjuvant chemotherapy increases the likelihood that breast conservation therapy for breast cancer patients will be successful. Breast Cancer Index (BCI), a gene expression assay combining HoxB13/IL17BR ratio and Molecular Grade Index (MGI), is prognostic for the risk of distant recurrence and overall survival in tamoxifen-treated and untreated breast cancer patients. It was previously reported that high risk patients, as determined by BCI, had a 10-fold greater probability of pathologic complete response (pCR) with neoadjuvant chemotherapy than low risk patients. The aim of the current study was to examine the relationship between BCI score and the use of breast conservation surgery (BCS) following treatment with neoadjuvant chemotherapy.

Material and Methods: A total of 145 women (tumor size T1, T2 and T3) were treated with neoadjuvant cheomtherapy for stage I-III breast cancer. RNA was extracted from FFPE tumor samples and a real-time RT-PCR assay was completed to generate a BCI score and risk group categorization as previously described (Jerevall et al. Br J Cancer 2011). The relationship between BCS, BCI and clinicopathological factors was examined using univariate and multivariate logistic regression.

Results: Of the 145 patients (67% ER+, 54% PR+, 57% >50 y old), 48 (33.1%) underwent BCS. BCI categorized 62 (43%) of patients as low, 50 (34%) as intermediate and 33 (23%) as high risk. The rate of BCS for the three BCI risk categories was 15% (low risk), 48% (intermediate risk) and 45% (high risk). In the low risk group, the rate of BCS was 15% corresponding to a NPV of 85%. This is consistent with previous data from the same cohort, where the NPV of BCI for pCR was 98.4% with only one patient in the low risk group achieving pCR. In univariate analysis, pathological tumor size (pT), ER, PR, grade and BCI were predictors of BCS. A higher BCI score was associated with higher likelihood of BCS (odds ratio of 3.90; CI: 1.45−10.49; p=0.0069). In multivariate analysis, pT and BCI remained significantly associated with BCS, while ER status was not (p=0.23). Results were similar in the subset of patients with T1 and T2 tumors (N=97). In this subset, BCI categorized 42% of patients as low, 37% as intermediate and 21% as high risk and the rate of BCS was 22%, 64% and 60%, respectively. In multivariate analysis of this subset, only BCI was significantly associated with BCS. In all patients, the concordance index based on a model with pT alone was 0.695. When BCI was incorporated into the model with pT, the concordance index increased to 0.801 (p= 0.0002).

Conclusion: In this study, we have shown that patients with higher BCI scores were associated with a higher likelihood of receiving BCS after neoadjuvant chemotherapy. Addition of BCI to tumor size increased accuracy in predicting likelihood of BCS. BCI along with standard pathological factors may improve estimation of individual probability of BCS after neoadjuvant chemotherapy. This study gives rise to the hypothesis that patients with low BCI should not be eligible for neoadjuvant chemotherapy since the likelihood of breast conservation is low. Further large confirmatory studies are necessary.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-13-08.

P2-12-12: Prognostic Utility of Breast Cancer Index for Late Relapse in Patients with Early Stage Breast Cancer

Background

Residual risk of relapse remains a substantial concern for breast cancer patients as greater than half of recurrences occur beyond the initial 5y of tamoxifen therapy. First generation multigene signatures provide further prognostic information to standard clinical and pathological factors, however, their utility is strongest for predicting early relapse (≤5y post-diagnosis), and they have limited prognostic value for late metastatic risk. Breast Cancer Index (BCI), a continuous risk index based on the combination of HOXB13:IL17BR (H:I) and the molecular grade index (MGI), estimates the individual risk of recurrence in ER+, LN- breast cancer patients. In this study, the prognostic performance of BCI for predicting early versus late relapse (≤5y vs >5y post-diagnosis) was examined.

Methods: Gene expression profiling was performed on RNA extracted from FFPE tumor samples from untreated, postmenopausal, ER+ early stage breast cancer patients in the randomized Stockholm Trial. RT-PCR assay, pre-defined BCI score, H:I and MGI cut-points, and risk group categorization were done as previously described (Jerevall et al., Br J Cancer 2011). Association of gene expression data with the clinical endpoint of time to distant metastasis was assessed by Kaplan-Meier analysis using the log rank test; time-varying coefficient Cox proportional models were used to estimate the time-dependent hazard ratios (HRs).

Results: Analyses included 274 ER+, LN- patients (51% PR+, 87% HER2−, 63% grade 2, 17.7 y median follow-up) who did not receive adjuvant tamoxifen treatment. BCI was significantly associated with 10-year distant metastasis-free survival, with probabilities of 91% (86-96%), 82% (74-91%), and 65% (52-80%) for the low, intermediate, and high-risk BCI groups, respectively (HR high versus low-risk group = 4.31; 95%CI, 2.23−8.33; P=0.00001). Risk stratification for the first 5-y post-diagnosis using time-varying coefficient Cox models showed both MGI and BCI were significantly prognostic with HRs of 6.13 (95% CI: 2.11−17.8; P=0.0009) and 5.77 (95% CI: 2.16−15.39; P=0.0005). For prediction of late relapse in the subset of patients that remained distant metastasis-free for at least 5-y (N=221), MGI decreased in prognostic utility (HR 1.65, 0.76−3.56; P=0.2), consistent with other proliferation-based gene signatures. In comparison, both H:I and BCI were significantly associated with risk of late relapse [HRs 2.89 (1.31−6.36; P=0.009); 3.31(1.3−8.39); P=0.012].

Prediction of late recurrences by breast cancer index in the NCIC CTG MA.17 cohort

2

Background: The MA.17 trial demonstrated that extended adjuvant endocrine therapy with letrozole after 5-y of tamoxifen markedly reduced the risk of recurrence in women with ER+ early stage breast cancer. This trial provides an opportunity to assess the ability of biomarkers to predict late recurrences in ER+ breast cancer. The Breast Cancer Index (BCI), a continuous risk index based on the combination of HOXB13:IL17BR (H:I) and the molecular grade index (MGI), estimates the individual risk of recurrence in ER+ breast cancer patients. In this study, the prognostic utility of BCI to predict late recurrences was examined.

Methods: FFPE tumor blocks were collected from patients who experienced a breast cancer recurrence up to unblinding of MA.17. Controls were matched 2:1 for age, tumor size, nodal status and prior chemotherapy, and were disease free for longer than cases. All cases were reviewed for standard histopathology and evaluated using the real-time RT-PCR BCI assay.

Results: Patient characteristics for the case-control study were similar to that from the overall study. Characteristics for cases (N=83) and controls (N=166) were not significantly different except for treatment. A higher percentage of controls compared to cases tended to be categorized as low risk by BCI (58% vs 43%), while a lower percentage of controls than cases tended to be categorized as high risk by BCI (34% vs 24%). In univariate analysis, treatment, BCI, H:I and HOXB13, but not tumor grade or MGI, were significant predictors of late recurrence. After adjusting for standard variables (age, tumor grade and treatment), BCI (OR 2.37; P=0.03), H:I (OR 2.55; P=0.04) and HOXB13 (OR 1.35; P=0.02) remained significant predictors of recurrence. HOXB13 expression at diagnosis predicted patient benefit from extended endocrine therapy with letrozole.

Conclusions: In this case-controlled study, the data demonstrate that BCI is a significant predictor of late recurrences in ER+ patients following 5-y of tamoxifen. The prognostic performance of BCI to predict late recurrences was largely dependent on HOXB13 expression. The integration of H:I and MGI within BCI provides prognostic utility for both early and late recurrences.

High bone turnover and accumulation of osteoid in patients with neurofibromatosis 1

Although it is known that neurofibromatosis 1 (NF1) patients suffer from vitamin D deficiency and display decreased bone mineral density (BMD), a systematic clinical and histomorphometrical analysis is absent. Our data demonstrate that NF1 patients display high bone turnover and accumulation of osteoid and that supplementation of vitamin D has a beneficial effect on their BMD.

INTRODUCTION

Neurofibromatosis 1 results in a wide range of clinical manifestations, including decreased BMD. Although it has been reported that NF1 patients have decreased vitamin D serum levels, the manifestation of the disease at the bone tissue level has rarely been analyzed.

METHODS

Thus, we performed a clinical evaluation of 14 NF1 patients in comparison to age- and sex-matched control individuals. The analysis included dual X-ray absorptiometry osteodensitometry, laboratory parameters, histomorphometric and quantitative backscattered electron imaging (qBEI) analyses of undecalcified bone biopsies.

RESULTS

NF1 patients display significantly lower 25-(OH)-cholecalciferol serum levels and decreased BMD compared to control individuals. Histomorphometric analysis did not only reveal a reduced trabecular bone volume in biopsies from NF1 patients, but also a significantly increased osteoid volume and increased numbers of osteoblasts and osteoclasts. Moreover, qBEI analysis revealed a significant decrease of the calcium content in biopsies from NF1 patients. To address the question whether a normalization of calcium homeostasis improves BMD in NF1 patients, we treated four patients with cholecalciferol for 1 year, which resulted in a significant increase of BMD.

CONCLUSION

Taken together, our data provide the first complete histomorphometric analysis from NF1 patients. Moreover, they suggest that low vitamin D levels significantly contribute to the skeletal defects associated with the disease.

Non-destructive and radiochemical determination of the neutron-induced production cross section of I-129 from Te and other neutron-induced cross sections on Te at 14.7 MeV

Cross sections of twelve neutron-induced reactions on tellurium at 14.7 MeV have been determined. Among them are the (n,2n) cross sections for the production of both 129Te isomers which were determined using gamma ray spectrometry. These reactions dominate the cosmogenic production of 129I in meteoroids and are therefore of special importance. In addition, the neutron-induced cross section on Te at 14.7 MeV for the production of 129I was also determined directly by accelerator mass spectrometry (AMS) after radiochemical separation. The results for the production cross section of 129I determined by the two methods agree within 5%.

On the origin of129I in rain water near Zürich

129I concentrations in precipitation at Dübendorf/Zürich, Switzerland, have been determined with monthly resolution for almost three years in the mid 1990s. The results confirm that annual mean129I concentrations in precipitation in central Europe have remained about constant since the late 1980s. Liquid and gaseous emissions from the nuclear fuel reprocessing plants at Sellafield and La Hague are discussed as the only possible sources of129I in precipitation in central Europe. Based on an upper limit estimate for iodine transferred from the sea to the atmosphere, the gaseous discharges constitute the potentially bigger129I reservoir for precipitation. Moreover, the time dependence of the annual gaseous129I releases from Sellafield and La Hague correlates much better with the129I concentrations in precipitation in central Europe since the late 1980s than does the time dependence of the liquid emissions from these sites. At monthly resolution, the129I concentrations in the precipitation samples close to Zürich exhibit a large variability. A meteorological transport analysis was carried out for four selected months with particularly low or high observed129I concentrations. It was found that meteorological transport alone, based upon assimilated wind fields and observed precipitation values, can not directly account for the large month-to-month variability.

Dementia and leukoencephalopathy due to lymphomatosis cerebri

Lymphomatosis cerebri (LC) is a rare variant of primary central nervous system lymphoma (PCNSL). Clinically, the disease typically presents with a rapidly progressive dementia and unsteadiness of gait. Its presentation on cerebral MRI, which is characterised by diffuse leukoencephalopathy without contrast enhancement, often causes diagnostic confusion1 with suspected diagnoses ranging from Binswanger's disease to leukoencephalopathy or encephalomyelitis. Here we report a patient with subacute dementia and diffuse bilateral white matter changes in the cerebral hemispheres and additional involvement of the brainstem, basal ganglia and thalamus on MRI. Initially, she was considered to suffer from an autoimmune encephalitis, transiently responded to immunosuppression but then developed multiple solid appearing cerebral lymphomas.

Galactic-cosmic-ray-produced 3He in a ferromanganese crust: any supernova 60Fe excess on earth?

An excess of 60Fe in 2.4-3.2 x 10(6) year old ferromanganese crust (237 KD) from the deep Pacific Ocean has been considered as evidence for the delivery of debris from a nearby supernova explosion to Earth. Extremely high ;{3}He/;{4}He (up to 6.12 x 10(-3)) and 3He concentrations (up to 8 x 10(9) atoms/g) measured in 237 KD cannot be supernova-derived. The helium is produced by galactic cosmic rays (GCR) and delivered in micrometeorites that have survived atmospheric entry to be trapped by the crust. 60Fe is produced by GCR reactions on Ni in extraterrestrial material. The maximum (3)He/(60)Fe of 237 KD (80-850) is comparable to the GCR (3)He/(60)Fe production ratio (400-500) predicted for Ni-bearing minerals in iron meteorites. The excess 60Fe can be plausibly explained by the presence of micrometeorites trapped by the crust, rather than injection from a supernova source.

Iodine-129 in soils from Northern Ukraine and the retrospective dosimetry of the iodine-131 exposure after the Chernobyl accident

Forty-eight soil profiles down to a depth of 40 cm were taken in Russia and Ukraine in 1995 and 1997, respectively, in order to investigate the feasibility of retrospective dosimetry of the 131I exposure after the Chernobyl accident via the long-lived 129I. The sampling sites covered areas almost not affected by fallout from the Chernobyl accident such as Moscow/Russia and the Zhitomir district in Ukraine as well as the highly contaminated Korosten and Narodici districts in Ukraine. 129I was analyzed by radiochemical neutron activation analysis (RNAA) and accelerator mass spectrometry (AMS). 127I was measured for some profiles by RNAA or ion chromatography (IC). The results for 127I demonstrated large differences in the capabilities of the soils to store iodine over long time spans. The depth profiles of 129I and of 137Cs showed large differences in the migration behavior between the two nuclides but also for each nuclide among the different sampling sites. Though it cannot be quantified how much 129I and 137Cs was lost out of the soil columns into deeper depths, the inventories in the columns were taken as proxies for the total inventories. For 129I, these inventories were at least three orders of magnitude higher than a pre-nuclear value of 0.084+/-0.017 mBq m(-2) derived from a soil profile taken in 1939 in Lutovinovo/Russia. From the samples from Moscow and Zhitomir, a pre-Chernobyl 129I inventory of (44+/-24) mBq m(-2) was determined, limiting the feasibility of 129I retrospective dosimetry to areas where the 129I inventories exceed 100 mBq m(-2). Higher average 129I inventories in the Korosten and Narodici districts of 130 and 848 mBq m(-2), respectively, allowed determination of the 129I fallout due to the Chernobyl accident. Based on the total 129I inventories and on literature data for the atomic ratio of 129I/131I=13.6+/-2.8 for the Chernobyl emissions and on aggregated dose coefficients for 131I, the thyroid exposure due to 131I after the Chernobyl accident was estimated for the inhabitants of four villages in the Korosten and of three villages in the Narodici districts. The limitations and uncertainties of the 129I retrospective dosimetry are discussed.

Quantitative monitoring of the mRNA expression pattern of the TGF-beta-isoforms (beta 1, beta 2, beta 3) during transdifferentiation of hepatic stellate cells using a newly developed real-time SYBR Green PCR

Current methods to determine the mRNA of the TGF-beta-isoforms, beta 1, beta 2, and beta 3, are not sensitive enough to detect small alterations in the expression levels. Therefore, we established a SYBR Green I-based real-time quantitative PCR procedure with fragment-specific standards. The advantage of gene-specific quantification is the possibility to be abstain from the need to compare results with a house-keeping gene having a different sequence and PCR efficiency. Reproducibility of the results and analytical variances of the real-time PCR assays were tested. In transdifferentiating rat hepatic stellate cells (HSC) the TGF-beta 1-mRNA was found to be the predominant isoform expressed followed by TGF-beta 3 and low amounts of TGF-beta 2-mRNA. An alteration of the TGF-beta 1,-beta 2, and -beta 3 ratio during HSC transdifferentiation could not be detected. Furthermore, the GAPDH mRNA expression varied during HSC activation, and thus is not recommended as a standard in real-time PCR quantifications.

Identification of a promoter in position 56 within the long control region of human papillomavirus type 18

The expression of the oncogenes E6 and E7 of the cervical cancer associated human papillomavirus type 18 was shown to be directed from the promoter in position 105 (P105), which is reportedly the only early promoter located within the long control region (LCR). However, in C33A cells transiently transfected with a reporter construct containing the LCR of HPV18 in front of the luciferase gene a transcript initiating at position 56 was present in addition to those initiating from the P105. A perfect TATA Box consensus sequence 30 bp further upstream, which is highly conserved among HPVs associated with cervical cancer, was required for the activity of this novel promoter, denoted here as P56. The P56 specific transcript obviously depends on promoter downstream sequences, since transcripts initiating from the P56 were not present when the CAT gene was cloned downstream of the LCR. We detected transcripts initiating from both the P105 and the P56 in primary keratinocytes harboring episomal HPV18 as well as in the HPV 18 positive cervical carcinoma cell lines HeLa, C4-1 and SW756. Our data suggest that in HPV18, the expression of the early viral proteins including the oncogenes might be directed from a second promoter, located within the LCR.

Expression of Pbx1b during mammalian organogenesis

Mammalian Pbx genes (Pbx1-3) encode a family of TALE homeodomain proteins that function as transcriptional regulators in numerous cell types (Curr. Opin. Genet. Dev. 8 (1998) 423). The present study highlights distinctive features of Pbx1b expression during mouse embryonic development as a framework to understand its biological functions. Immunohistochemical analyses demonstrate extensive expression of Pbx1b throughout post-implantation development, with highest levels observed during early to mid-gestation. Its initial distribution is predominantly associated with condensing mesoderm, however, Pbx1b displays dynamic expression patterns in derivatives of all principal germ layers. In particular, Pbx1b localizes to sites of mesenchymal-epithelial interactions during periods of active morphogenesis in tissues such as the lung, kidney, tooth buds and vibrissae follicles. Furthermore, BrdU labeling studies reveal that Pbx1b expression domains partially overlap with regions of cellular proliferation. Taken together, these data suggest that Pbx1b contributes to multiple cellular processes during embryogenesis, which may include roles in cell-autonomous regulation as well as in the mediation of tissue interactions.

Wet and dry deposition of 129I in Seville (Spain) measured by accelerator mass spectrometry

Iodine-129 (T1/2 = 1.57 x 10(7) yr) concentrations have been determined by accelerator mass spectrometry in rainwater samples taken at Seville (southwestern Spain) in 1996 and 1997. This technique allows a reduction in the detection limits for this radionuclide in comparison to radiometric counting and other mass spectrometric methods such as ICP-MS. Typical 129I concentrations range from 4.7 x 10(7) 129I atoms/l (19.2%) to 4.97 x 10(9) 129I atoms/l (5.9%), while 129I depositions are normally in the order of 10(8)-10(10) atoms/m2d. These values agree well with other results obtained for recent rainwater samples collected in Europe. Apart from these, the relationship between 129I deposition and some atmospheric factors has been analyzed, showing the importance of the precipitation rate and the concentration of suspended matter in it.

HoxA9-mediated immortalization of myeloid progenitors requires functional interactions with TALE cofactors Pbx and Meis

Specific Hox genes are implicated in leukemic transformation, and their selective genetic collaboration with TALE homeobox genes, Pbx and Meis, accentuates their oncogenic potential. The molecular mechanisms underlying these coordinate functions, however, have not been characterized. In this study, we demonstrate that HoxA9 requires its Pbx interaction motif as well as its amino terminus to enhance the clonogenic potential of myeloid progenitors in vitro. We further show that HoxA9 forms functional trimeric DNA binding complexes with Pbx and Meis-like proteins on a modified enhancer. DNA binding complexes containing HoxA9 and TALE homeoproteins display cooperative transcriptional activity and are present in leukemic cells. Trimeric complex formation on its own, however, is not sufficient for HoxA9-mediated immortalization. Rather, structure-function analyses demonstrate that domains of HoxA9 which are necessary for cellular transformation are coincident with those required for trimer-mediated transcriptional activation. Furthermore, the amino terminus of HoxA9 provides essential transcriptional effector properties and its requirement for myeloid transformation can be functionally replaced by the VP16 activation domain. These data suggest that biochemical interactions between HoxA9 and TALE homeoproteins mediate cellular transformation in hematopoietic cells, and that their transcriptional activity in higher order DNA binding complexes provides a molecular basis for their collaborative roles in leukemogenesis.