Abstract PD8-02: Residual axillary involvement in early breast cancer in patients with positive sentinel nodes after neoadjuvant chemotherapy (NACT)

Background:The association between pathological complete remission (pCR) in the breast and clinical/pathological parameters is well established, whereas the role of these parameters in the prediction of residual axillary involvement after NACT is unclear. The goal is to identify a subset of patients who do not need axillary treatment. We used data from Arm B of the SENTINA trial to analyze this association.

Methods:Patients from arm B of the SENTINA trial with clinically and sonographically unsuspicious axillary nodes but with histologically proven involvement of SLNs prior to NACT were analyzed. All patients had SLNB and axillary dissection after NACT. Univariate analyses were performed to evaluate the association between clinical/pathological parameters and axillary involvement after NACT.

Results:Arm B of the SENTINA study contained 360 patients, 318 of which were evaluable with respect to the above parameters. After NACT 71/318 (22.3%) patients had involved SLNs or non-SLNs; 71/318 (22.3%) had a pCR in the breast. We observed a significant association between pCR in the breast and negative ER status, negative PR status, positive HER2 status, triple negative (TN) status, tumor size before and after NACT, multifocality, lobular morphology and axillary involvement after NACT. Regarding residual axillary burden only the associations with lobular morphology, extracapsular invasion, multifocality, positive HER2 status and pCR in the breast were statistically significant.

Conclusion:Our analysis demonstrates that patients enrolled in the SENTINA trial with clinically and sonographically unsuspicious axillary nodes but proven histological involvement of SLNs prior to NACT have positive axillary nodes in 22.3 % after NACT. This rate is confirming similar results from other groups. Although we found statistically significant associations between pCR in the breast and clinical/pathological parameters, only the association between lobular type, extracapsular invasion, positive HER2 status and pCR in the breast and residual axillary involvement after NACT were statistically significant. We cannot clearly identify a subset of patients for whom axillary treatment after NACT could be safely omitted if SLNs were positive. Our data are well in line with recently presented data demonstrating that the association between pCR in the breast and free axillary nodes after NACT is particularly strong in patients with TN and HER2 positive tumors. This question will be addressed in future trials currently under development.

Citation Format: Kolberg H-C, Liedtke C, Bauerfeind I, Fehm T, Fleige B, Hauschild M, Helms G, Lebeau A, Schmatloch S, Schrenk P, Schwentner L, Stäbler A, Loibl S, Untch M, Kühn T. Residual axillary involvement in early breast cancer in patients with positive sentinel nodes after neoadjuvant chemotherapy (NACT) [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 PD8-02.

Abstract P3-12-22: Targeted intraoperative radiotherapy (TARGIT IORT) during breast conserving surgery for early stage breast cancer in patients with breast augmentation with implants

Background: Targeted intraoperative radiotherapy (TARGIT) has become a standard option during breast conserving surgery for selected cases of early breast cancer and over 20,000 patients have been treated in over 300 centers around the world. Although a growing number of patients are presenting with implant breast augmentation, no data has been published regarding the safety of TARGIT with implants in situ. TARGIT IORT as a replacement for whole breast irradiation is an important issue in this context because of the high rates of capsular fibrosis following EBRT in such patients.

Methods: We are reporting a case series of 12 patients who received TARGIT during breast conserving surgery for early breast cancer, had undergone breast augmentation with implants before and wanted their implants to stay in situ. Patients were informed that no published data existed and decided on this approach on an individual basis. 3 patients received additional EBRT after TARGIT IORT because of the presence of EIC or LVI. TARGIT IORT was performed using Intrabeam - 50 kV – X-rays delivering 20 Gy prescribed at the surface of the tumor bed during the initial lumpectomy procedure.

Results:Patient characteristics are given in table 1. Follow-up varied from 78 months to 3 months. 11 patients presented with invasive breast cancer, 1 patient with DCIS. There were no procedure related complications and none of the patients have needed their implant removed. 1/12 patients (ID 7) was diagnosed with a local recurrence in a distant quadrant after 36 months of follow-up. In 11/12 patients no breast-cancer-related events occurred.

Patient characteristicsIDER/PR/HER2GradeSentinel NodesTumor Size (mm)Distance Implant to Tumor (mm)EBRT after IORTFollow up time (months)1pos/pos/neg2pN1mi (sn)95No622pos/neg/neg2pN0 (sn)1913Yes543pos/pos/neg3pN0 (sn)0.85Yes324pos/pos/neg2pN0 (sn)611No155pos/pos/neg3pN0 (sn)71Yes146pos/pos/neg1pN0 (sn)515No117pos/pos/neg2pN0 (sn)7not reportedNo378pos/pos/na1 (DCIS)N/A8not reportedNo789pos/pos/neg2pN0 (sn)15not reportedNo1510pos/neg/neg1pN0 (sn)144No4411pos/pos/neg2pN0 (sn)91No1112pos/pos/neg2pN0 (sn)75No3Table 1

Conclusion: This series of patients with TARGIT during breast conserving surgery for early breast cancer after breast augmentation with implants in situ revealed no safety concerns. Our case series gives some confidence in discussing this option with suitable patients. To expand this series, we are gathering details about other cases from the whole TARGIT group worldwide.

Citation Format: Kolberg H-C, Uhl V, Massarut S, Holmes D, Liedtke C, Whineray Kelly E, Lövey G, Vaidya JS. Targeted intraoperative radiotherapy (TARGIT IORT) during breast conserving surgery for early stage breast cancer in patients with breast augmentation with implants [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 P3-12-22.

Abstract GS5-06: No survival benefit of chemotherapy escalation in patients with pCR and “high-immune” triple-negative early breast cancer in the neoadjuvant WSG-ADAPT-TN trial

Background:Immune markers such as tumor infiltrating lymphocytes (TILs), CD8, PDL1, PD1 and other protein or mRNA-based genomic markers have been identified as prognostic / predictive in TNBC regarding survival / chemotherapy (CTx) efficacy.

In the adjuvant WSG-PlanB trial, patients with high TILs and/or CD8 by mRNA had excellent outcome, irrespective of anthracycline use; in the neoadjuvant ADAPT-TN trial, high PDL1, PD1 and CD8 and/or TILs were predictive for pCR. Still, optimal markers for potential treatment de-escalation have yet to be determined. Here, we analyse for the first time impact of immune mRNA-based markers and TIL's as prognostic and predictive survival markers.

Methods: TNBC patients (ER/PR<1%, HER2-,) were randomized to neoadjuvant 4x nab-paclitaxel 125 mg/m2/gemcitabine 1000 mg/m2 d1/8 q3w (gem arm) or 4x nab-paclitaxel 125 mg/m2/carboplatin AUC2 day 1/8 3-weekly (q3w) (carbo arm). Primary endpoint of WSG-ADAPT-TN was pCR (ypT0/is/ypN0); secondary endpoints included translational analyses, e.g., TILs or expression of 119 genes by nCounter platform. Standard adjuvant chemotherapy (4xEC) was optional (not randomized) in patients achieving pCR after 12 weeks. According to protocol, 1st safety survival analysis was performed after 3y median follow-up.

Results: Present translational analysis included 306 of 336 TNBC patients (36 months median FU). pCR was associated with significantly better survival (3y EFS: 92% vs. 71%, p<.001), but despite substantially higher pCR in the carbo arm (46% vs. 29%), no significant EFS advantage was seen (p=.6) (gem: 78%; carbo: 80%; 3y-EFS).

Bivariate Spearman correlations among CD8, PD1, and PDL1 were strongly positive; their correlations with TILs were moderately positive.

Preliminary Cox analysis of EFS was performed with clinical variables (cN, cT, menopausal status); neoadjuvant study arm; pCR; TILs; proliferation markers (baseline Ki67 by IHC, scores derived from PAM50); baseline immune markers; risk scores; and individual gene expression scores previously identified as prognostic for pCR in one or both neoadjuvant arms. Independent prognostic factors included pCR, cN, Ki67, PD1, and CD8; these were entered into (prognostic) interaction analysis. The resulting model contained cN, high Ki67 and low TILs as (unfavorable) main effects and the interaction of (higher) PD1*pCR (favorable).

Among pCR patients, the groups with/without additional adjuvant CTX were similar with respect to explanatory factors. Baseline TILs, Ki67, cN, and PD1 were entered into exploratory predictive analysis; the model retained only the interaction [adjuvant CTx * (fractionally ranked) PD1]. In patients with pCR, those with low PD1 benefited from standard anthracycline-containing adjuvant CTx, whereas patients high PD1 did not with an 98% 3y-EFS.

Conclusions: Our exploratory results suggest independent prognostic impact of mRNA markers and TIL's in early TNBC. Patients with both pCR (after 12 weeks) and “high-immune” signature (defined here by PD1) had excellent 3y-EFS and may be candidates for treatment de-escalation (e.g. omission of anthracyclines), whereas “low-immune” pCR patients may benefit from standard adjuvant poly-chemotherapy.

Citation Format: Gluz O, Nitz U, Liedtke C, Prat A, Christgen M, Feuerhake F, Garke M, Grischke E-M, Forstbauer H, Braun M, Warm M, Hackmann J, Uleer C, Aktas B, Schumacher C, Kuemmel S, Pelz E, Gebauer D, Paré L, Kates R, Wuerstlein R, Kreipe HH, Harbeck N. No survival benefit of chemotherapy escalation in patients with pCR and “high-immune” triple-negative early breast cancer in the neoadjuvant WSG-ADAPT-TN trial [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 GS5-06.

Abstract P6-03-06: Androgen supplementation in patient derived xenografts in androgen receptor positive breast cancer to increase engraftment and growth rate

Background:

The European fund for regional development (EFRE) supported Precision Oncology and Personalized Therapy Prediction (POP) Project is establishing preclinical models to further the development of personalized therapy options. In the subgroup breast cancer the current goal is to increase the growth and engraftment rates of breast cancer patient derived xenografts (PDX) models.

Methods:

Breast cancer patients of the Department of Gynecology with Breast Center Charité Universitätsmedizin Berlin, Germany are recruited since May 2017. In total 29 tissue samples were collected and included so far.

Treatment naive and treatment refractory patients, tripple negative breast cancer (TNBC), hormone receptor positive (HR+) and Her2 postivie tumors, primary disease, recurrence or metastasis are sampled. Fresh tumor tissue is extracted via surgery or biopsy. The materials are then implanted into female immunodeficient NOG mice. To establish PDX models for HR+ breast cancer the mice received estrogen supplementation.

To increase engraftment and growth rates androgen receptor (AR) testing and subsequently androgen replacement was started since April 2018.

Up to date, 6 new samples have been collected. One HR+ and two TNBC samples tested also positive for AR. These samples are currently in passage 0 (p0) and are now supplied with androgens to increase engraftment and growth rate. One already established AR+ TNBC PDX is being regrown with androgen supplementation to compare growth rates.

Results:

Out of the initial 23 tissue samples ten (six HR+ and four TNBC) have been able to be engrafted into PDX mice.

The TNBC PDX models are one in p1, one in p2, one in p3 and one is being tested with systemic therapy. Engraftment time in p1 were between 19 and 97 days. Growth time to passagable size between 21 and 112 days.

The HR+ PDX models are four in p1 and two in p2. Engraftment time in p1 was between 26 and 123 days. Growth time to passagable size has been achieved in 2 HR+ PDX within 17 to 48 days.

The engraftment/growth rates and times of the androgen supplemented PDX models will be presented.

Conclusion:

Breast cancer growths in humans slowly and this is also the case in the PDX models. To achieve faster growth and higher engraftment rates androgen supplementation in AR+ breast cancer might be an additional enhancive factor.

Citation Format: Kiver VII, Wulf-Goldenberg A, Jurmeister PS, Schweiger C, Gorea O, Hoffmann J, Denkert C, Keilholz U, Liedtke C, Blohmer J-U. Androgen supplementation in patient derived xenografts in androgen receptor positive breast cancer to increase engraftment and growth rate [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 P6-03-06.

Abstract PD8-03: Conversion rates from positive to negative axillary involvement in breast cancer patients presenting with biopsy-proven axillary metastases prior to primary systemic therapy (PST) – A transSENTINA subproject

Background:

Modern chemotherapy carries a high potential of converting patients with clinically suspicious axillary nodes (cN+) prior to PST to clinically (ycN0) or pathologically (ypN0) negative nodes after PST. Clinical and sonographical axillary assessment, however, may be inadequate and therefore pathological assessment of suspicious axillary nodes is recommended. We analyzed the association between clinical / pathological parameters and positive to negative conversion in patients with biopsy-proven axillary metastases in Arm C of the SENTINA trial (i.e. patients with “true conversion”).

Methods:

Arm C of the SENTINA trial included patients converting from cN+ to ycN0 through PST from a prospective study. We limited our analysis to patients who had biopsy-proven axillary involvement. Univariate regression analysis was carried out to assess the association between patients with vs. without axillary disease after PST in i) patients with biopsy-proven involvement and ii) patients without biopsy proof of metastases.

Results:

Among 596 patients in arm C of the SENTINA trial with clinically and or sonographically suspicious ipsilateral axillary nodes, 439 (73,7%) 157 (26,3%) patients had a biopsy. In 152 patients (96,8%), lymph node metastases were confirmed and in 5 patients (3,2%), no malignant cells were identified. In both groups, we found a significant association (p<0,05) between increased rate of axillary conversion and small tumor diameter after PST, absence of multifocality, absence of lymphovascular invasion (LVI), ER and/or PR negativity, HER2 negativity, triple negative disease, and complete pathological response (pCR). No multiple testing corrections were performed due to an exploratory setting. However, only among patients with biopsy-proven involvement prior to PST, we found grade-3-tumors to be significantly associated with reduced probability of residual axillary involvement (76.1 vs. 33.8%, compared to G1 and G2, p=0.0323).

Conclusion:

Our analysis demonstrates that in patients with biopsy-proven axillary involvement before NST, parameters associated with axillary conversion are similar to those among patients classified as having nodal disease based on clinical and or sonographical assessment (cN+). Our analyses demonstrate that in biopsy-proven axillary metastases before NST, modern chemotherapy regimens result in significant rates of axillary conversion. This underscores the need to deescalate axillary staging / treatment with the goal to further avoid unnecessary axillary surgery.

Citation Format: Liedtke C, Kolberg H-C, Krajewska M, Bauerfeind I, Fehm T, Fleige B, Helms G, Lebeau A, Staebler A, Loibl S, Untch M, Kühn T. Conversion rates from positive to negative axillary involvement in breast cancer patients presenting with biopsy-proven axillary metastases prior to primary systemic therapy (PST) – A transSENTINA subproject [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 PD8-03.

Systematic analysis of parameters predicting pathological axillary status (ypN0 vs. ypN+) in patients with breast cancer converting from cN+ to ycN0 through primary systemic therapy (PST)

Optimization of axillary staging among patients converting from clinically node-positive disease to clinically node-negative disease through primary systemic therapy is needed. We aimed at developing a nomogram predicting the probability of positive axillary status after chemotherapy based on clinical/pathological parameters. Patients from study arm C of the SENTINA trial were included. Univariable/multivariable analyses were performed for 13 clinical/pathological parameters to predict a positive pathological axillary status after chemotherapy using logistic regression models. Odds ratios and 95%-confidence-intervals were reported. Model performance was assessed by leave-one-out cross-validation. Calculations were performed using the SAS Software (Version 9.4, SAS Institute Inc., Cary, NC, USA). 369 of 553 patients in Arm C were included in multivariable analysis. Stepwise backward variable selection based on a multivariable analysis resulted in a model including estrogen receptor (ER) status (odds ratio (OR) 3.916, 95% confidence interval (CI) 2.318-6.615, p < 0.001), multifocality (OR 2.106, 95% CI 1.203-3.689, p = 0.0092), lymphovascular invasion (OR 9.196, 95% CI 4.734-17.864, p < 0.001), and sonographic tumor diameter after PST (OR 1.034, 95% CI 1.010-1.059, p = 0.0051). When validated, our model demonstrated an accuracy of 70.2% using 0.5 as cut-point. An area under the curve of 0.81 was calculated. The use of individual parameters as predictors of lymph node status after chemotherapy resulted in an inferior accuracy. Our model was able to predict the probability of a positive axillary nodal status with a high accuracy. The use of individual parameters showed reduced predictive performance. Overall, tumor biology was the strongest parameter in our models.

Abstract P2-12-06: Re-excision rates in breast conserving surgery for invasive breast cancer after neoadjuvant chemotherapy with and without the use of a radiopaque tissue transfer and X-ray system

Background: Published re-excision rates after breast conserving surgery for invasive breast cancer vary between 20 and 50%. In patients after neoadjuvant chemotherapy even higher re-excision rates may result from difficulties in defining the surgical target particularly in cases with excellent treatment response. Specimen radiography is reducing re-excision rates, however, defining involved margins is often difficult using standard approaches. Devices allowing horizontal and vertical examination and an exact topographic localization of the lesion in the resected tissue could reduce re-excision rates by an intraoperative detection of involved margins.

Methods: 80 patients with invasive breast cancer receiving breast conserving surgery after neoadjuvant chemotherapy and an indication for wire marking by mammography were included in this analysis. All tumors were marked with titanium clips prior to chemotherapy. In 40 patients specimen radiography was performed in a standard approach (control group), in 40 patients a tissue transfer and X-ray system based on a non-radiopaque board with radiopaque topographic markers and a stand for cranio-caudal X-rays was used (study group). A univariate analysis was carried out to evaluate the association between the use of the radiopaque tissue transfer system and the re-excision rate using a logistic regression model. Calculations were performed using the XLSTAT Biomed Software (Version 19.03, Addinsoft, NY, USA.).

Results: 19/80 patients (23.75%) required re-excision because of involved margins; among those patients, 14/40 (35%) were in the control group and 5/40 (12.5%) in the study group. The association between the use of the radiopaque tissue transfer system and the lower re-excision rate was statistically significant (p=0.023).

Conclusion: Our analysis provides a rationale for the use of a radiopaque tissue transfer system for specimen radiography in breast conserving surgery after neoadjuvant chemotherapy for invasive breast cancer in order to reduce re-excision rates. Based on these results we are planning a study including also patients receiving primary surgery.

Citation Format: Kolberg H-C, Akpolat-Basci L, Stephanou M, Wetzig S, Cubuk Y, Gerharz J, Liedtke C. Re-excision rates in breast conserving surgery for invasive breast cancer after neoadjuvant chemotherapy with and without the use of a radiopaque tissue transfer and X-ray system [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 P2-12-06.

Abstract P2-10-03: Genomic markers but not molecular subtypes provide prognostic impact and predict anthracycline efficacy in early triple-negative breast cancer: Results from the prospective WSG PlanB trial

Background: Optimal treatment, particularly use of anthracyclines in aggressive triple-negative breast cancer (TNBC), is still a controversial issue in early BC management. However, TNBC exhibits substantial molecular heterogeneity: for example, the immune phenotype seems to be associated with better outcome. An important clinical issue in early TNBC is to quantify the impact of subtypes as well as individual genes on survival and especially on anthracycline benefit.

Methods: In PlanB, patients with ER and PR&lt;1% (local or central lab), HER2- EBC were treated by TC (6 cycles Docetaxel/Cyclophosphamide) or EC-Doc (4xEpirubicin/Cyclophosphamideà4xDocetaxel) (overall n=2449, HER2-). RNA isolation was successfully performed in n=402/449 patients with available follow-up. Gene (n=119) expression data by Nanostring® platform were entered into univariate and multivariate Cox models for disease-free survival (DFS) to identify genes (and combinations) with potential prognostic and/or predictive impact. Median follow-up was 60 months.

Results: RNA expression results were available in n=394 (203 TC vs. 191 EC-Doc): PAM-50 subtype: basal-like 82%; HER2-enriched 7%; luminal (A or B) 3.5%; normal-like 7.4%. Median age was 54; 78% were node-negative. In patients with “discordant” tumors (HR positive by local or central assessment), 76% were still basal-like, compared to 86% in “concordant” TNBC. Of 27 patients with HER2-enriched subtype, HER2 status was positive by central assessment in only five cases (18%).

Within this TN cohort, 5y DFS was similar in TC (83%) and EC-Doc (79%) arms; positive nodal status and tumor size &gt;2 cm were (unfavorable) clinical-pathological prognostic markers. Prognostic or predictive impacts of molecular subtype, risk of recurrence subgroups, or proliferation indices were not seen.

Twelve genes (incl. CD8, EGFR, GPR160, SPINT2) showed potential multivariate prognostic impact by entering the “forwards stepwise” multivariate Cox model for DFS. The upper half of patients according to the resulting “twelve-gene signature” had well over 90% 5y-DFS, whereas the lowest quartile had under 60% 5-y DFS. Several genes (incl. ERBB2, FOXC1) showed potential for a predictive impact regarding TC vs. EC-Doc by interaction analysis. Further details and perspectives for testing the robustness of these potential impacts will be presented at the meeting.

Conclusions

To our knowledge, these are the first results from a prospective, adjuvant taxane-based trial regarding molecular predictors of anthracycline efficacy and PAM-50-based prognostic factors in early TNBC. ERBB2 expression, but not HER2-enriched subtype, was predictive for A-benefit in HER2-negative BC. Molecular heterogeneity of TNBC beyond basal-like vs. non-basal-like subtype is clinically relevant and should be considered for patient stratification in ongoing trials with combination therapy. The identified prognostic gene signature should be validated in the WSG-ADAPT-TN and other TNBC trials.

Citation Format: Gluz O, Liedtke C, Prat A, Christgen M, Gebauer D, Kates R, Pelz E, Clemens M, Warm M, Aktas B, Kuemmel S, Pare L, Krabisch P, Kreipe HH, Wuerstlein R, Nitz U, Harbeck N. Genomic markers but not molecular subtypes provide prognostic impact and predict anthracycline efficacy in early triple-negative breast cancer: Results from the prospective WSG PlanB trial [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 P2-10-03.

De-escalation strategies in HER2-positive early breast cancer (EBC): final analysis of the WSG-ADAPT HER2+/HR- phase II trial: efficacy, safety, and predictive markers for 12 weeks of neoadjuvant dual blockade with trastuzumab and pertuzumab ± weekly paclitaxel

BACKGROUND

Response rates in HER2-overexpressing EBC treated with neoadjuvant chemotherapy and trastuzumab (T) have been improved by addition of pertuzumab (P). The prospective, phase II, neoadjuvant WSG-ADAPT HER2+/HR- trial assessed whether patients with strong early response to dual blockade alone might achieve pathological complete response (pCR) comparable to that of patients receiving dual blockade and chemotherapy.

PATIENTS AND METHODS

Female patients with HER2+/HR- EBC (M0) were randomized (5:2) to 12 weeks of T + P ± weekly paclitaxel (pac) at 80 mg/m2. Early response was defined as proliferation decrease ≥30% of Ki-67 (versus baseline) or low cellularity (<500 invasive tumor cells) in the 3-week biopsy. The trial was designed to test non-inferiority for pCR in early responding patients of the T + P arm versus all chemotherapy-treated patients.

RESULTS

From February 2014 to December 2015, 160 patients were screened, 92 were randomized to T + P and 42 to T + P+pac. Baseline characteristics were well balanced (median age 54 versus 51.5 years, cT2 51.1 versus 52.4%, cN0 54.3 versus 61.9%); 91.3% of patients completed T + P per protocol and 92.9% T + P+pac. The pCR rate in the T + P+pac arm was 90.5%, compared with 36.3% in the T + P arm as a whole. In the T + P arm, 24/92 were classified as non-responders, and their pCR rate was only 8.3% compared with 44.7% in responders (38/92) and 42.9% in patients with unclassified early response (30/92). No new safety signals were observed in the study population.

CONCLUSION

Addition of taxane monotherapy to dual HER2 blockade in a 12-week neoadjuvant setting substantially increases pCR rates in HER2+/HR- EBC compared with dual blockade alone, even within early responders to dual blockade. Early non-response under dual blockade strongly predicts failure to achieve pCR.

Breast cancer and genomic testing

Makes a real difference

Abstract P1-09-05: The role of immune and apoptosis markers for prediction of pCR in the WSG-ADAPT HER2+/HR+ phase II trial evaluating 12-weeks of neoadjuvant TDM1 ± endocrine therapy (ET) versus T + ET in HER2-positive hormone-receptor-positive early breast cancer (EBC)

Background: Immune and apoptosis biomarkers are potential prognostic/predictive markers in HER2+ EBC. High PD-L1 expression was shown to be predictive for lower pCR after chemotherapy+trastuzumab+/-pertuzumab, particularly in HER2+, ER- disease. Yet, HER2+ EBC co-expressing hormone receptors is a distinct entity.

The ADAPT HER2+/HR+ phase II trial (n=376) compared 12 weeks of neoadjuvant T-DM1 + ET vs. trastuzumab (T)+ET and demonstrated pCR rates of about 41% in both (well tolerated) T-DM1 arms.

Methods: In order to identify potential early predictors for pCR (i.e. no invasive tumor in breast and lymph nodes), immune markers (PDL1 on infiltrating immune cells (IIC) and on tumor cells (TC); CD8 in invasive margin and in tumor center) and apoptosis markers (bcl-2; mcl-2) were determined by immunohistochemistry (IHC; H-scores) in core biopsy sections obtained at primary diagnosis and at cycle 2. For multivariate logistic regression, each biomarker (separately), clinical factors (Ki-67, cT, cN) and therapy were entered. All analyses were exploratory.

Results:Biomarkers were available in up to 326 patients (pts) at baseline and up to 170 pts at 3 weeks (due to low tumor content in 2nd core biopsy).

Baseline IIC-PDL1 was associated with pCR in the T-DM1 arm (OR 2.89; 95%CI: 1.11-7.51); IIC-PDL1 at cycle 2 was not associated with pCR.

PD-L1 expression in TC was rare (2%); cycle-2 TC-PD-L1 was associated with pCR in all pts and in the pooled TDM-1 arms.

High baseline CD8 in tumor center was associated with pCR in the whole cohort (OR 2.4; CI: 1.04 – 5.5) and in the T+ET arm (OR=10.1; CI: 1.12 - 91.6) and at cycle 2 in all pts (OR=9.52; CI: 2.17 – 41), in pooled TDM-1 arms (OR=15.7; CI: 2.49 – 99), and in TDM-1+ET (OR=25.05; CI: 2.12 – 295). Increases in this marker also predicted pCR in all pts, pooled TDM-1, and in TDM-1+ET. Association of cycle-2 CD8 in tumor center with pCR persisted in multivariate models.

Lower baseline CD8 in invasive margin was associated with pCR in the T-DM1 arm (OR=0.09; CI: 0.01-0.69), but at cycle 2 in all pts (OR=18.1; CI: 1.60 – 204) and in pooled TDM-1 arms (OR=23.5; CI: 1.1 - 500). This positive impact persisted in multivariate models.

Bcl-2 expression at baseline was associated with non-pCR in all pts (OR=0.28, CI: 0.12 - 0.66), in the pooled T-DM1 arms (OR=0.216, CI: 0.08 - 0.61), and particularly in the T-DM1+ET arm (OR=0.14; CI: 0.03 - 0.71). This association persisted in multivariate analysis. At cycle 2, lower bcl-2 had OR=0.16 (CI: 0.03 - 0.96) in the pooled T-DM1 arms. No association with efficacy was seen for mcl-1.

Conclusions: The WSG-ADAPT HER2+/HR+ phase II trial is the first international trial to focus on HER2+/HR+ EBC alone and the first to show substantial pCR rates of &gt; 40% after only 12 weeks of T-DM1 -- without standard chemotherapy.

Expression of bcl-2 may affect resistance to T-DM1. High immune activity at baseline and/or cycle 2 seems to be associated with pCR. The association of CD8 expression and its changes with therapy efficacy is complex and could depend on ET.

Further biomarker analyses are ongoing and will be presented at the meeting.

Citation Format: Harbeck N, Nitz UA, Matthias C, Kates R, Braun M, Kümmel S, Schumacher C, Potenberg J, Kraemer S, Kleine-Tebbe A, Augustin D, Aktas B, Forstbauer H, Tio J, Liedtke C, Grischke E-M, de Haas SL, Deurloo R, Schumacher J, Wuerstlein R, Kreipe HH, Gluz O. The role of immune and apoptosis markers for prediction of pCR in the WSG-ADAPT HER2+/HR+ phase II trial evaluating 12-weeks of neoadjuvant TDM1 ± endocrine therapy (ET) versus T + ET in HER2-positive hormone-receptor-positive early breast cancer (EBC) [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 P1-09-05.

Abstract P3-13-06: Development and validation of a nomogram predicting pathological axillary status (ypN0 vs. ypN+) in a subgroup of patients converting from cN+ to ycN0 through neoadjuvant therapy (NAT) – A transSENTINA substudy

Background: Particularly among patients converting from cN+ to ycN0 status through neoadjuvant therapy (NAT) the optimal method and extent of axillary staging is unclear. The aim of this analysis was to develop a nomogram predicting the probability of positive axillary status (ypN+) after PST among these patients based on clinical and pathological parameters.

Methods:Patients converting from cN+ to ycN0 due to PST included in a prospective study (SENTINA, Arm C) were included. Univariate and multivariate analyses were carried out to evaluate the association between 14 clinical/pathological parameters and pathological axillary status (ypN0 vs ypN+) using logistic regression models. Model accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were assessed applying leave-one-out cross-validation (LOOCV) and ROC analyses. Different cut-points were evaluated. Calculations were performed using the SAS Software (Version 9.4, SAS Institute Inc., Cary, NC, USA.).

Results: Arm C contained 553 patients, 369 patients were evaluable with respect to the above parameters. Univariate analyses revealed a significant association between pathological axillary status and ER status (odds ratio (OR) 4.05, 95% confidence interval (95%CI) 2.81-5.83), PR status (OR 3.07, 95%CI 2.16-4.36), multifocality (OR 2.37, 95%CI 1.57-3.58), lymphovascular invasion (OR 8.61, 95%CI 5.12-14.46), detection of a SLN after NAT (OR .56, 95%CI .36-.87), detection method (IHC vs routine: OR .46, 95%CI .27-.78; IHC vs serial HE: OR .72, 95%CI .49-1.07; serial hematoxylin eosin (HE) vs routine: OR .639, 95%CI .39-1.04), clinical tumor size (OR 1.051, 95%CI 1.03-1.07) and pCR-status in the breast (ypT0 and ypTis vs others, OR .11, 95%CI .08-.17). A multivariate model was fitted including significant clinical parameters. Stepwise backward variable selection was carried out resulting in a model including ER status (OR 3.81, 95%CI 2.25-6.44), multifocality (OR 2.22, 95%CI 1.26-3.92), LVI (OR 9.16, 95%CI 4.68-17.90), detection of a SLN after NAT (OR .50, 95%CI .26-.95) and clinical tumor size (OR 1.03, 95%CI 1.01-1.06). In LOOCV, this model demonstrated an accuracy of 73% (sensitivity 73%, specificity 72%, PPV 75%, NPV 70%) using .5 as cut-off. Based on the performed ROC analysis an area under the curve (AUC) of 0.81 was calculated.

Conclusion: A model using ER status, multifocality, LVI, detection of a SLN after NAT and clinical tumor size was built to predict pathological axillary status (ypN+) with a high accuracy. If successfully validated based upon an independent dataset, this nomogram could allow advising patients for / against axillary surgery in case of clinical axillary conversion after NAT.

Citation Format: Liedtke C, Kolberg H-C, Kerschke L, Goerlich D, Bauerfeind I, Fehm T, Fleige B, Hauschild M, Helms G, Lebeau A, Schmatloch S, Schrenk P, Schwentner L, Staebler A, von Minckwitz G, Loibl S, Untch M, Kuehn T. Development and validation of a nomogram predicting pathological axillary status (ypN0 vs. ypN+) in a subgroup of patients converting from cN+ to ycN0 through neoadjuvant therapy (NAT) – A transSENTINA substudy [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 P3-13-06.

Abstract P2-01-35: A one-day protocol with activities lower than 20 MBq for the detection of sentinel lymph nodes - Experience after 150 cases

Introduction:

Common protocols for the detection of sentinel lymph nodes (SLN) in early breast cancer often include injection of the tracer one day before surgery. In order to detect enough activity on the day of surgery, the applied activity in many protocols is as high as several hundred MBq. Even in common one-day protocols the activity applied is often up to 50 MBq. We developed a one-day protocol with a mean activity lower than 20 MBq in order to reduce radiation exposure for patients and staff. Here we are presenting our experience after 150 cases.

Material and methods:

150 patients with clinically and sonographically negative axilla (cN0) and no multicentricity underwent a SLN biopsy using a low-dose protocol performed on the day of surgery. After ultrasound-guided injection of the tracer (Technetium99) lymphoscintigraphy was performed in all cases. 7 minutes before the first cut 5 ml blue dye was injected in the region of the areola. Fresh-frozen sections of the SLN(s) were not performed.

Results:

In 149 of 150 patients (99.3%) at least one SLN could be identified by lymphoscintigraphy. The detection rate during surgery with combined tracers Technetium99 and blue dye was 100%. The mean applied activity was 17.8 MBq (9-20). A mean number of 1.3 (0-5) SLNs were identified by lymphoscintigraphy, a mean number of 1.7 (1-5) SLNs were removed during sentinel lymph node biopsy. 36 patients received a secondary axillary dissection according to the historical standard because of involved SLNs. In 11 cases (30.6%) additional involved lymph nodes were found.

Conclusion:

One-day protocols with an activity lower than 20 MBq are a safe alternative to two-day protocols with significantly higher radiation doses. Using Technetium99 and blue dye in a dual tracer approach, detection rates of 100% are possible in clinical routine with minimal radiation exposure for patients and staff. The number of removed lymph nodes, the rate of secondary axillary dissections and the number of cases with additional involved lymph nodes is not higher than in published trials.

Citation Format: Kolberg H-C, Afsah S, Winzer U, Akpolat-Basci L, Stephanou M, Liedtke C. A one-day protocol with activities lower than 20 MBq for the detection of sentinel lymph nodes - Experience after 150 cases [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 P2-01-35.

Comparison of prognostic and predictive impact of genomic or central grade and immunohistochemical subtypes or IHC4 in HR+/HER2- early breast cancer: WSG-AGO EC-Doc Trial

INTRODUCTION

Potential prognostic and predictive markers in early, intermediate-risk breast cancer (BC) include histological grade, Ki-67, genomic signatures, e.g. genomic grade index (GGI), and intrinsic subtypes. Their prognostic/predictive impact in hormone receptor (HR: ER and/or PR) positive/HER2- BC is controversial. WSG-AGO EC-Doc demonstrated superior event-free survival (EFS) in patients with 1-3 positive lymph node receiving epirubicin/cyclophosphamide-docetaxel (EC-Doc) versus 5-fluoruracil/epirubicin/cyclophosphamide (FEC).

METHODS

In a representative trial subset, we quantify concordance among factors used for clinical chemotherapy indication. We investigate the impact of central histology (n = 772), immunohistochemistry for intrinsic subtyping and IHC4, and dichotomous (GG) or continuous (GGI) genomic grade (n = 472) on patient outcome and benefit from taxane chemotherapy, focusing on HR+/HER2- patients (n = 459).

RESULTS

Concordance of local grade (LG) with central (CG) or genomic grade was modest. In HR+/HER2- patients, low (GG-1: 16%), equivocal (GG-EQ: 17%), and high (GG-3: 67%) GG were associated with respective 5-year EFS of 100%, 93%, and 85%. GGI was prognostic for EFS within all LG subgroups and within CG3, whereas IHC4 was prognostic only in CG3 tumors.In unselected and HR+/HER2- patients, CG3 and luminal-A-like subtype entered the multivariate EFS model, but not IHC4 or GG. In the whole population, continuous GGI entered the model [hazard ratio (H.R.) of 75th versus 25th = 2.79; P = 0.01], displacing luminal-A-like subtype; within HR+/HER2- (H.R. = 5.36; P < 0.001), GGI was the only remaining prognostic factor.In multivariate interaction analysis (including central and genomic grade), luminal-B-like subtype [HR+ and (Ki-67 ≥20% or HER2+)] was predictive for benefit of EC-Doc versus FEC in unselected but not in HR+/HER2- patients.

CONCLUSION

In the WSG-AGO EC-Doc trial for intermediate-risk BC, CG, intrinsic subtype (by IHC), and GG provide prognostic information. Continuous GGI (but not IHC4) adds prognostic information even when IHC subtype and CG are available. Finally, the high interobserver variability for histological grade and the still missing validation of Ki-67 preclude indicating or omitting adjuvant chemotherapy based on these single factors alone.

TRIAL REGISTRATION

The WSG-AGO/EC-Doc is registered at ClinicalTrials.gov, NCT02115204.

Abstract P6-08-07: Association between phenotype of triple negative breast cancer cell lines and sensitivity against eribulin mesylate in vitro

Introduction:

Diagnosis of triple negative breast cancer (TNBC) is associated with adverse prognosis particularly in case of chemotherapy resistance. TNBC is a heterogeneous entity and seems to consist of at least six distinct molecular subtypes (Lehman subtypes) with distinct chemotherapy sensitivity. The cytotoxic agent eribulin induces tumor cell apoptosis through depolymerization of the cell spindle apparatus. Based on clinical data it has recently been suggested that TNBC is particularly sensitive against eribulin. The goal of this analysis was to compare (i) TNBC vs. non TNBC lines and (ii) cell lines of distinct TNBC subtypes with regard to eribulin sensitivity in vitro.

Methods:

17 established breast cancer cell lines comprising both TNBC (4 basal-like 1/2; 1 mesenchymal; 3 mesenchymal stem cell; 1 interleukin; 2 luminal AR; 1 unclassified) and non-TNBC (n=5) phenotypes were cultured and subjected to cell viability assay (MTT test), migration experiment (scratch assay), apoptosis analysis (Western Blot experiment for PARP cleavage) and quantitative RT-PCR analysis (for GABRP gene expression) after exposure to eribulin or control. Furthermore, gene expression of 8 genes known to induce malignant transformation (MMP7, ELF5, YBX1, RARRES1, PRNP, SOX 10, EGFR and GABRP) was analyzed via quantitative RT-PCR analysis in the triple negative cell line MDA-MB 231 after exposure to eribulin or control.

Results:

The effect of eribulin on the cell viability varied to a lesser extent among the TNBC compared to the non-TNBC cell lines though we could not observe a significant difference between both groups. Mentionable the TNBC cell line DU 4475 representing the interleukin phenotype displayed a significant stronger resistance to eribulin compared to all other phenotypes. A decelerated migration could be observed in the TNBC cell line MDA-MB 231 after exposure to the IC50 concentration of eribulin compared to non-treated cells.

Induction of apoptosis by eribulin treatment was verified by PARP cleavage in various TNBC cell lines. GABRP known to be overexpressed especially in basal like TNBC showed a slight increase in gene expression after exposure to eribulin in various phenotypes of TNBC - most prominent in MDA-MB 231. Additionally, upregulation of ELF5 and downregulation of YBX1 and PRNP, and, to a lesser extent, of MMP7 and SOX 10 gene expression could be investigated in MDA-MB 231 after eribulin treatment.

Conclusion:

We did not observe a significant association with regard to eribulin sensitivity between TNBC and non-TNBC. Chemotherapy sensitivity varied to a lesser extent among TNBC cell lines compared to non-TNBC cell lines. Eribulin inhibits cell proliferation and migration, induces apoptosis in TNBC, and influences gene expression of overexpressed genes in TNBC known to participate in and induce malignant transformation.

Though the current work did not explicitly specify one phenotype of TNBC for eribulin treatment regarding chemotherapy sensitivity, we identified possible target genes influenced by eribulin treatment, e. g. GABRP, and therefore need further investigation for a potential treatment approach combining eribulin with e. g. GABRP inhibitor.

Citation Format: Bräutigam K, Mitzlaff K, Uebel L, Steinert G, Köster F, Polack S, Rody A, Liedtke C. Association between phenotype of triple negative breast cancer cell lines and sensitivity against eribulin mesylate in vitro. [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 P6-08-07.

Abstract P2-07-01: Association of TILs with clinical parameters, recurrence score, and prognosis in patients with early HER2-negative breast cancer (BC) – A translational analysis of the prospective WSG planB trial

Introduction:

Tumor-infiltrating lymphocytes (TILs) have been associated with prognosis and with chemotherapy response among patients with BC, particularly in presence of high-risk features. The WSG planB trial randomized 2448 patients with HER2- N0/1 BC for comparison of anthracycline-free (6xTC) vs. standard anthracycline-taxane chemotherapy (4xEC-4xDoc). Recurrence Score® (RS) was incorporated for risk stratification in hormone receptor positive (HR+) BC. The present analysis focuses on the correlation of TILs with clinical/pathological parameters and their prognostic impact among planB patients.

Methods:

Stromal TILs were evaluated using a pathologist and two-observer approach. Three independent observers evaluated digital sections on H&E staining as previously suggested (Salgado et al., Ann Oncol. 2014); the median of the three values (TILmed) was used for statistical analysis. Spearman correlations of TILmed with clinical/pathological parameters (including central KI67 expression, quantitative ER measurements, nodal involvement, and RS) and univariate impact on event-free survival (EFS) were analyzed.

Results:

Our analysis included 300 patients with HR- and 1124 patients with HR+ HER2- BC. Both in HR- and HR+ BC, a significant association between TILmed and (i) central grading (correlation coefficient r=0.147, p=0.012 and r=0.195, p&lt;0.001, respectively) and (ii) central Ki67 expression (r=0.202, p=0.001 and r=0.152 and p&lt;0.001) was observed. Among HR+ cases, a significant association between TILmed and quantitative ER measurements (r=-0.412, p=0.041) and RS (r=0.190, p&lt;0.001) was found. Furthermore, univariate Cox analysis revealed a significant association between TILmed (coded as fractional rank) and event-free survival (EFS). The hazard ratio of 75th to 25th percentile was 1.58 (95%CI: 1.06-2.36, p=0.025). This impact was not separately significant in HR subgroups due to lack of events

Conclusion:

In this dataset, presence of stromal TILs was moderately associated with clinical features of high-risk breast cancer (including RS) and decreased EFS. TILs will be evaluated as a prognostic or predictive factor (in multivariate and subgroup analyses) when the outcome results are evaluated after prolonged follow up. Furthermore, an updated analysis including the complete planB dataset will be presented.

Citation Format: Liedtke C, Gluz O, Heinisch F, Feuerhake F, Kreipe HH, Clemens M, Nuding B, Kraemer S, Reimer T, Svedman C, Shak S, Nitz U, Kates RE, Harbeck N, Christgen M. Association of TILs with clinical parameters, recurrence score, and prognosis in patients with early HER2-negative breast cancer (BC) – A translational analysis of the prospective WSG planB trial. [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 P2-07-01.

Abstract P1-13-01: Comparison of 12 weeks neoadjuvant Nab-paclitaxel combined with carboplatinum vs. gemcitabine in triple- negative breast cancer: WSG-ADAPT TN randomized phase II trial

Background: Pathological complete response (pCR) is associated with improved prognosis in TNBC, but optimal chemotherapy remains unclear. Use of weekly nab- paclitaxel (Nab-Pac) vs. conventional paclitaxel and also addition of carboplatinum(Carbo) to anthracycline-taxane(A/T) containing chemotherapy results in significantly higher pCR rates in TNBC with unclear impact on survival and increased toxicity.

The ADAPT study seeks to compare Carbo vs. gemcitabine(Gem) added to nab- paclitaxel as a short 12-week A-free regimen. It also assesses efficacy in early responders vs. non-responders by 3-week proliferation and/or imaging response.

Methods: ADAPT TN compares 12-week neoadjuvant regimens: Carbo vs. Gem combined with Nab-Pac and aims to identify early-response markers for pCR (yPN0 and ypT0/is). TNBC patients (centrally confirmed ER/PR &lt;1%, HER2 neg.), cT1c- cT4c, cN0/+ were randomized to arm A (Nab-Pac 125/Gem 1000 d1,8 q3w) vs. B (Nab-Pac 125/Carbo AUC2 d1,8 q3w). Randomization was stratified by center and nodal status. The trial is powered for pCR comparison by therapy arm and by presence vs. absence of early response markers. Pre-planned interim analysis aimed to identify a dynamic biomarker, e.g. drop of 3-week Ki-67, and to validate trial assumptions.

Results: 336 patients were enrolled from 47 centers between 06/13-02/15 (n=182 ArmA: Nab-Pac/Gem and n=154 ArmB: Nab-Pac/Carbo). 90% and 95% completed therapy according to protocol respectively (n.s.). Median age was 50y. At baseline: A/B: 73% and 74%% had G3 tumors, median Ki-67 of 70% and 75%; 62.6% and 62.9%% had cT2-4c tumors, pN0 status prior to chemotherapy was confirmed in 50.5% and 50%, respectively.

pCR (ypT0/is/ypN0) was A: 28.7% and B: 45.9% (p&lt;0.001). Total pCR (ypT0/ypN0) was A: 25.8% and B: 45.2% respectively (p &lt;0.001).

Nab/Gem arm was associated with significantly higher frequency of dose reductions (20.6% vs. 11.9% (p=0.03), treatment related SAE's (13% vs. 5%, p=0.02), grade 3-4 infections (6.1% vs. 1.3%, p=0.04) and ALAT elevations (11.7 vs. 3.3%, p=0.01) compared to the Nab-Carbo arm.

Within the planned interim analysis (n=130: A/B: 69/61), baseline Ki-67 (Nab- Pac/Carbo arm), age&gt;50 years, and low cellularity (&lt;500 tumor cells and/or Ki-67≤10% in the 3-week biopsy) (Nab-Pac/Gem arm) were positively associated with pCR by logistic regression analysis (separately by therapy arm). In all patients, therapy arm itself was significant for pCR.

Validation of responder definitions for the whole study will be presented at the meeting.

Conclusions:

This is the first large randomized study comparing two short 12-week anthracycline- free regimens in unselected TNBC. Our results suggest superior efficacy and excellent toxicity of Nab-Pac/Carbo vs. Gem. Longer A/T-Carbo containing regimens render quite comparable pCR rates, thus overtreatment by 4xEC in unselected TNBC may be present in some patients. Early response criteria seem to differ according to regimen; their assessment may be impaired by substantial tumor necrosis already after the first therapy cycle.

Citation Format: Gluz O, Nitz U, Liedtke C, Christgen M, Sotlar K, Grischke EM, Forstbauer H, Braun M, Warm M, Hackmann J, Uleer C, Aktas B, Schumacher C, Bangemann N, Lindner C, Kuemmel S, Clemens M, Potenberg J, Staib P, Kohls A, Pelz E, Kates RE, Wuerstlein R, Kreipe HH, Harbeck N. Comparison of 12 weeks neoadjuvant Nab-paclitaxel combined with carboplatinum vs. gemcitabine in triple- negative breast cancer: WSG-ADAPT TN randomized phase II trial. [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 P1-13-01.

Abstract P4-14-06: Neoadjuvant chemotherapy with docetaxel, carboplatin and weekly trastuzumab (TCH) is active in HER2-positive early breast cancer: Results after a median follow-up of over 4 years

Background:

HER2-positive breast cancer is known to carry an adverse prognosis compared to HER2-negative disease, which may however be compensated by the use of HER2-targeted agents. Therefore, most patients with HER2-positive disease larger than 5 mm receive chemotherapy and trastuzumab. Data from adjuvant trials have shown that the combination of docetaxel, carboplatin and weekly trastuzumab (TCH) is well tolerated and as effective as anthracycline containing regimes. Previous investigations on neoadjuvant treatment with TCH showed pCR-rates in the range of 40%, however, survival data have not yet been presented. Here we present 4-year follow-up data for a cohort of 51 patients treated with neoadjuvant TCH.

Methods:

We treated 51 patients with operable HER2-positive breast cancer with a neoadjuvant schedule of docetaxel (75 mg/m2) and carboplatin (AUC 6) q3w and trastuzumab (2(4)mg/kg) q1w. Lymph node involvement was verified by SLNB or core-cut-biopsy. Patients were diagnosed at a mean age of 55 years, 68.6% had ER positive tumors, 39.2% presented with grade 3 disease and 49% of patients were node-positive. Patients were monitored every two cycles by ultrasound. After 6 cycles of chemotherapy all patients had surgery. Axillary dissection was performed in case of positive lymph node status prior to TCH. After surgery trastuzumab was continued q3w up to one year.

Results:

In 50 patients TCH could be administered as planned without dose reductions or delays. One patient suffered from an allergic reaction on taxane after the second cycle, resulting in replacement by gemcitabine. Side effects were mild, no grade III/IV toxicities occurred and no case of cardiomyopathia was observed. 21 (41.18%) patients achieved a pCR, 18 (72.0%) patients converted from cN+ to ypN0. Outcome data at a median follow-up of 51.6 months are as follows.

 All patients (n=51)pCR (n=21)N+ (n=25)cN+ → ypN0 (n=18)ER positive (n=35)G3 (n=20)DFS (n/%)42/82.3517/80.9517/68.016/88.8931/88.5716/80.0DDFS (n/%)46/90.219/90.4820/80.017/94.4433/94.2918/90.0OS (n/%)48/94.1821/100.022/88.018/100.034/97.1419/95.0

Conclusion:

Outcome following neoadjuvant TCH as observed in our analysis compares well to outcome data observed in adjuvant trastuzumab trials such as HERA (4-year follow-up; DFS 78.6% and OS 89.3%) or BCIRG006 (36-month follow-up; DFS 82% and OS 91% in the TCH-arm). Particularly among patients with ER positive disease and those experiencing axillary conversion we obseverd an excellent outcome. Importantly, TCH was well tolerated in our cohort. Therefore our data support the use of TCH as neoadjuvant therapy regimen for patients with HER-positive breast cancer. They also strongly encourage the use of docetaxel and carboplatin as chemotherapy backbone in studies investigating the dual blockade with trastuzumab and pertuzumab in the neoadjuvant setting.

Citation Format: Kolberg H-C, Akpolat-Basci L, Stephanou M, Hannig CV, Liedtke C. Neoadjuvant chemotherapy with docetaxel, carboplatin and weekly trastuzumab (TCH) is active in HER2-positive early breast cancer: Results after a median follow-up of over 4 years. [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 P4-14-06.

The carbon tetrachloride model in mice

Recently, the need for more standardized operation procedures in experimental liver fibrosis research was suggested due to dramatic changes in European animal welfare rules. Here, we present a short series of standard operation procedures (SOPs) summarizing the most relevant and widely accepted experimental models for the induction of liver injury leading to liver fibrosis. The described procedures are based on the long-term experience of the Collaborative Research Centre 'Organ Fibrosis: From Mechanisms of Injury to Modulation of Disease' (http://www.sfbtrr57.rwth-aachen.de/), which is supported by the German Research Foundation (SFB/TRR57). These SOPs will help to improve standardization of fibrosis models and to increase the comparability of data between different laboratories with the aim of reducing animal experimentation according to the principle that was proposed in 1959 by Russell and Burch as an ethical framework for conducting scientific experiments with animals, namely the replacement, refinement and reduction (3R) principle. In the first section we focus on the carbon tetrachloride (CCl4) model in mice, which is the toxic model of liver fibrosis induction most commonly used worldwide.

Partial hepatectomy in mice

The surgical procedure of two-thirds partial hepatectomy (PH) in rodents was first described more than 80 years ago by Higgins and Anderson. Nevertheless, this technique is still a state-of-the-art method for the community of liver researchers as it allows the in-depth analysis of signalling pathways involved in liver regeneration and hepatocarcinogenesis. The importance of PH as a key method in experimental hepatology has even increased in the last decade due to the increasing availability of genetically-modified mouse strains. Here, we propose a standard operating procedure (SOP) for the implementation of PH in mice, which is based on our experience of more than 10 years. In particular, the SOP offers all relevant background information on the PH model and provides comprehensive guidelines for planning and performing PH experiments. We provide established recommendations regarding optimal age and gender of animals, use of appropriate anaesthesia and biometric calculation of the experiments. We finally present an easy-to-follow step-by-step description of the complete surgical procedure including required materials, critical steps and postoperative management. This SOP especially takes into account the latest changes in animal welfare rules in the European Union but is still in agreement with current international regulations. In summary, this article provides comprehensive information for the legal application, design and implementation of PH experiments.

Primary Therapy of Patients with Early Breast Cancer: Evidence, Controversies, Consensus: Opinions of German Specialists to the 14th St. Gallen International Breast Cancer Conference 2015 (Vienna 2015)

For the first time, this year's St. Gallen International Consensus Conference on the treatment of patients with primary breast cancer, which takes place every two years, was held not in St. Gallen (Switzerland) but - for logistical reasons - in Vienna (Austria) under its usual name. The 2015 St. Gallen International Consensus Conference was the 14th of its kind. As the international panel of the St. Gallen conference consists of experts from different countries, the consensus mirrors an international cross-section of opinions. From a German perspective, it was considered useful to translate the results of the votes of the St. Gallen conference into practical suggestions, particularly in light of the recently updated treatment guideline of the Gynecologic Oncology Group (AGO-Mamma 2015) in Germany. A German group consisting of 14 breast cancer experts, three of whom are members of the international St. Gallen panel, has therefore provided comments on the results of this year's votes at the 2015 St. Gallen Consensus Conference and their impact on clinical care in Germany. The 14th St. Gallen conference once again focused on surgery of the breast and the axilla, radio-oncologic and systemic treatment options for primary breast cancer depending on tumor biology, and the clinical use of multigene assays. The conference also considered targeted therapies for older and for younger patients, including the diagnosis/treatment of breast cancer during and after pregnancy and the preservation of fertility.

Diethylnitrosamine (DEN)-induced carcinogenic liver injury in mice

The toxic properties of various nitrosamines in animals and humans are well established. The parenteral or oral administration of the smallest quantities of diethylnitrosamine (DEN) or dimethylnitrosamine (DMN) results in severe liver damage. Most prominent are intense neutrophilic infiltration, extensive centrilobular haemorrhagic necrosis, bile duct proliferation, fibrosis, and bridging necrosis that ends in hepatocarcinogenesis. Due to the robustness of the induced hepatic alterations, the application of DEN in rodents has become an attractive experimental model for studies aimed at understanding the pathogenetic alterations underlying the formation of liver cancer, which represents one of the most common malignancies in humans worldwide. However, several studies have shown that the hepatocarcinogenic effects of nitrosamines might vary with the genetic background of the animals, their sex, their age, and other factors that might impact the outcome of experimentation. We present general guidelines for working with DEN, and a detailed protocol that allows the establishment of highly reproducible liver cancer in mice. The outcome of liver injury after the application of DEN in mice, as estimated by the formation of cirrhosis and cancer, appears to be a suitable animal model for the analysis of some aspects and processes that promote the pathogenesis of hepatocellular carcinoma in humans.

Expression of secreted protein acidic and rich in cysteine (SPARC) in breast cancer and response to neoadjuvant chemotherapy

BACKGROUND

Secreted protein acidic and rich in cysteine (SPARC) has been suggested as a new biomarker and therapeutic target in breast cancer, as well as other tumor types.

PATIENTS AND METHODS

We evaluated the frequency of SPARC expression among different molecular breast cancer subtypes and its role for therapy response after neoadjuvant chemotherapy. In this study, pretherapeutic core biopsies of 667 patients from the neoadjuvant GeparTrio trial were evaluated for SPARC expression by immunohistochemistry using a standardized immunoreactive score (IRS).

RESULTS

An increased SPARC expression (IRS ≥6) was observed in 26% of all tumors. In triple-negative tumors, SPARC expression was increased in 37% of tumors, compared with other molecular subtypes (23% HR+/HER2-, 29% HR+/HER2+ and 22% HR-/HER2+; P = 0.038). Increased SPARC expression was associated with an increased pathological complete response (pCR) rate of 27%, compared with 15% in tumors with low SPARC expression (P < 0.001). In the triple-negative subgroup, pCR rates were 47% in tumors with high SPARC expression, compared with 26% in tumors with low SPARC expression (P = 0.032). In multivariable analysis, SPARC was independently predictive in the overall population (P = 0.010) as well as the triple-negative subgroup (P = 0.036).

CONCLUSIONS

SPARC is frequently expressed in breast cancer with triple-negative breast cancer revealing the highest expression rate. High SPARC expression of the primary tumor is associated with a higher chance of achieving a pathological complete remission after TAC or TAC-NX chemotherapy. As SPARC is an albumin-binding protein and might mediate intratumoral accumulation of albumin bound drugs, SPARC should be further evaluated as a predictive marker especially for response to albumin-bound drugs like nab-paclitaxel.

CLINICAL TRIAL NUMBER

NCT00544765.

Abstract P4-04-06: Systematic analysis of molecular subgroups and age in patients with breast cancer

Background: Breast cancer (BC) molecular subgroups show significant differences with regard to prognosis. Similarly, young age at diagnosis is significantly associated with an unfavorable prognosis.

Methods: Our aim was to analyze the association between BC molecular subtypes and age at diagnosis. Publically available gene expression data (Affymetrix U133A) of 3488 BC patients was analyzed using MAS5.0 and pooled into a single database. Age information was available for 2604 of the patients (74.7%). Of a total of 579 cases with TNBC, 394 samples with most comparable array data were selected to avoid batch effects as previosly described. Age information was available for 309 of these 394 patients (78.4%). Significance Analysis of Microarrays (SAM) was performed to identify genes with differential expression according to age at diagnosis in these 309 patients with TNBC.

Results: Patients &lt;40 years significantly more often presented with triple negative BC compared to patients 40-50 and &gt;50 (34.8 vs. 25.4 vs. 17.3%, respectively). In contrast, a luminal A subtype was diagnosed less often in patients &lt; 40 yrs (20.6 vs. 31.9 vs. 41.1%, respectively). Although we observed significant differences for EFS according to i) age at diagnosis and ii) molecular subtype, EFS differences between patients of distinct age were only modest after stratification for molecular subtype. Among patients with TNBC, 134 genes were upregulated and 627 genes were downregulated in patients &lt; 40 yrs compared to patients ≥ 40 yrs (median FDR &lt; 4%). Several of the downregulated genes in young TNBC patients belong to a metagene for the molecular-apocrine subtype of TNBC and several upregulated genes represent cell cycle genes. However, the effects for individual genes were rather small. Conclusion: The frequency of molecular subgroups differs with age at diagnosis. Young age at diagnosis is significantly associated with adverse prognosis. Within the group of TNBC patients young age is associated with high proliferation and a basal-like phenotype and inversely correlated with the molecular-apocrine subtype of TNBC.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-04-06.

Abstract P5-04-02: Biopsy of metastases impacts treatment choice and patient outcome in breast cancer – Final results of the WSG/DETECT PRIMET study

Background: Changes in tumor biology (e.g., hormone receptor (HR) / HER2 status or grading) between primary tumor (PT) and metastatic tissue (MT) could impact outcome and treatment choice following first recurrence in breast cancer (BC).

Methods: PRIMET is a prospectively planned, retrospective multicenter quality assurance study comparing BC phenotype in tissue from PT, involved lymph nodes (LN) of primary disease, and disease recurrence (DR). PRIMET comprises 635 patients from WSG and DETECT trial groups (11 centers), whose BC was diagnosed between 1980 and 2010; follow-up continued until mid-2012. Patients with unilateral primary BC suffering subsequent local-regional and / or distant DR (LDR / DDR) were included. Clinical data including ER, PR, HER2, and grade were obtained from a systematic chart review in PT and DR; in two centers, these factors were also measured in LN by central pathology. Dependence of post-recurrence survival (PRS) on changes in tumor biological factors was analyzed.

Results: Data from 635 patients (including 592 cM0, of whom 46% had LDR only) were available for analysis. Median follow-up in patients alive at analysis was 101 months. Considering cM0 patients, median overall survival (OS) was 176 months; median recurrence-free survival (RFS) was 48 months (DDR present: 45 months; LDR only: 50 months). Median PRS was 59 months (DDR present: 45 months; LDR only: 127 months). In patients with first DR within 18 months, median PRS was 29 months, in others 79 months. HR status in PT/MT was: 61.5% (+/+), 13.2% (+/-), 5.5% (-/+) 19.8% (-/-). Of the HR “switches” in either direction with LN biopsy available, about half already occurred in lymph nodes. HER2 status in PT/MT was: 14.6% (+/+), 6.7% (+/-), 14.9% (-/+) 63.8% (-/-). With LN biopsy available, most losses of HER2 overexpression were already observed in LN tissue, whereas acquired HER2 overexpression was observed in about half of LN biopsies. Triple negative (TN: HR-, HER2-) percentages were 74.4% (non-TN/non-TN), 9.0% (non-TN/TN), 6.1% (TN/non-TN), 10.5% (TN/TN).

Compared to HR+/+, loss of HR+ status (HR+/-) was significantly associated with poorer PRS (hazard ratio: 1.62; p = 0.01). Significantly better PRS was associated with a switch from G3 to G1/2 (hazard ratio: 0.47; p = 0.02). Tumors that switched to TN or that lost HER2 overexpression showed trends toward poorer PRS. Persistent TN was associated with poorer PRS than other combinations.

Among patients with DDR, metastasis in bone only was associated with better PRS than primary or visceral (CNS, lung, liver, etc.) metastasis. Among patients with visceral metastasis, negative HR status in metastasis was associated with poorer survival than in HR+/+ not only for HR-/- (p = 0.02), but also for HR+/- (p = 0.04).

Conclusions:

Tumor biology of primary and metastatic tissue differed in a substantial fraction of patients (HR: 19%; HER2: 22%, TN: 18%); more than half of all changes occurred already in LN. Status changes particularly loss of HR+ status, had significant prognostic impact. We can expect a switch in HR or HER2 status (or both) in about 38% of metastatic tissue biopsies, with presumably important clinical therapeutic consequences, in particular regarding targeted therapies.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-04-02.

Abstract P3-06-05: Expression of SPARC in human breast cancer and its predictive value in the GeparTrio neoadjuvant trial

Background: Secreted protein acidic and rich in cysteine (SPARC) is an albumin-binding protein and associated with poor prognosis in multiple cancers.

The aim of this analysis was to determine the frequency of SPARC expression among different molecular breast cancer subtypes and to evaluate its predictive value for therapy response after neoadjuvant anthracycline/taxane based chemotherapy (CTX) in participants of the GeparTrio trial.

Methods: We evaluated tumoral SPARC expression by immunohistochemistry on tissue microarrays (TMAs) constructed from formalin-fixed paraffin-embedded (FFPE) pre-treatment core biopsies from 667 patients (pts) of the GeparTrio trial. The details of the GeparTrio study design are described elsewhere (von Minckwitz, JNCI 2008). Cutoffs for SPARC expression were determined using the web-based software Cutoff Finder (http://molpath.charite.de/cutoff/).

Results: SPARC protein expression was measurable by IHC on the TMAs and 176 (26.4 %) of 667 tumors were SPARC positive. SPARC expression was increased in pts with triple-negative breast cancer (TNBC) compared to hormone receptor or HER2 positive subtypes (p = 0.039).

SPARC positivity was associated with an increased pCR rate in the overall population (p &lt; 0.001). SPARC negative tumors had a pCR rate of 15%, which increased to 27% in SPARC positive tumors. Similarly, in TNBC the pCR rate increased from 26% in SPARC negative tumors to 47% in SPARC positive tumors (p = 0.032).

In multivariate logistic regression analysis adjusted for standard clinicopathological factors, SPARC was independently predictive in the overall population (p = 0.010) as well as the subgroups of pts with TNBC (p = 0.036).

Conclusions: SPARC is expressed in all biological breast cancer subtypes with TNBC revealing the highest expression rate. Our data suggest that SPARC expression may provide predictive information for response to neoadjuvant CTX.

As SPARC is an albumin-binding protein and might mediate intratumoral accumulation of nab-Paclitaxel, prospective analysis of SPARC expression is planned in the GeparSepto trial.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-06-05.

Chemotherapy-Induced Amenorrhea - An Update

Because of the heterogeneity in the definition of chemotherapy-induced amenorrhea (CIA) there are distinct differences in the literature with regard to its incidence as well as its dependence on various influencing factors. The occurrence of CIA varies greatly depending on the applied chemotherapy. The pathogenesis of CIA is especially based on a reduction of ovarian reserves. Various sonographic and biochemical factors can be used to exclude or confirm CIA. This is particularly important when an endocrine therapy with tamoxifen is not possible and the use of aromatase inhibitors is under consideration. CIA and especially the frequently thereby resulting early menopause can lead to pronounced restrictions in the quality of life of the affected patients, not least due to the resulting infertility. On the other hand, various studies have shown that CIA may have a positive prognostic significance. Thus, the identification of measures to prevent CIA (for example, through the use of GnRH analogues) is of particular importance.

Predictive value of HER2 serum levels in patients treated with lapatinib or trastuzumab -- a translational project in the neoadjuvant GeparQuinto trial

BACKGROUND

We were able to demonstrate a predictive value of serum HER2 (sHER2) in patients receiving trastuzumab in the neoadjuvant GeparQuattro trial. However, the role of sHER2 in patients receiving neoadjuvant therapy (NT) with lapatinib is still unclear.

METHODS

The neoadjuvant GeparQuinto trial compared trastuzumab vs lapatinib in addition to chemotherapy in HER2-positive primary breast cancer patients. The sHER2 levels were measured by enzyme-linked immunosorbant assay in 210 patients, of whom 109 (52%) patients received trastuzumab and 101 (48%) lapatinib at three different time points.

RESULTS

Twenty-two percent of patients had elevated baseline sHER2 levels (>15 ng ml⁻¹). A decrease of sHER2 levels (>20%) in the trastuzumab and lapatinib-treated group during NT was seen in 44% and 24% of the patients, an increase of sHER2 levels (>20%) was seen in 6% and 41% of patients, respectively. Higher pre-chemotherapy sHER2 levels were associated with higher pathological complete remission (pCR) rates in the entire study cohort (OR 1.8, 95% CI 1.02-3.2, P=0.043). A decline of sHER2 levels (>20%) during NT was a predictor for pCR in the lapatinib-treated patient group (OR: 11.7, 95% CI 1.3-110, P=0.031).

CONCLUSION

Results of this study demonstrate that sHER2 levels change differently during NT depending on the anti-HER2 treatment strategy. Elevated baseline sHER2 levels (>15 ng ml⁻¹) and a decrease of sHER2 levels (>20%) early after therapy initiation are both relevant criteria to predict response to lapatinib-based treatment.

P1-06-03: Predictive Value of HER2, Topoisomerase-II (Topo-II) and Tissue Inhibitor of Metalloproteinases (TIMP-1) for Efficacy of Taxane-Based Chemotherapy in Intermediate Risk Breast Cancer – Results from the EC-Doc Trial

Background: Despite extensive research, there is still no consensus on optimal predictors for use of taxane-based chemotherapy (cht) in early breast cancer. Some studies have revealed HER2 as a significant predictive marker for efficacy of taxanes and anthracyclines. TIMP-1 and Topo-II are reported to be predictive for anthracycline efficacy. In our previous reports, both Ki-67≥20% and central G3 status emerged as significant predictors for taxane benefit. We have now compared HER2 and Topo-II (as protein expression and gene amplification) and TIMP-1 immunoreactivity as well as factor combinations (HT (HER2/TIMP-1) and 2T (Topo-II/TIMP-1) regarding their predictive value for benefit from taxane-based cht.

Methods: The EC-Doc trial randomized 1950 patients with 1–3 positive LN to 6x CEF/CMF vs. 4xEC-4xDoc. Significantly better DFS and OS favoring EC-Doc have been previously reported (Nitz et al., SABCS 2008). Protein expression and gene amplification data as well central histology/grade were available for 772 patients. Survival analysis was performed using Cox proportional hazards and Kaplan-Meier statistics. Analysis of HER2 survival impact status was prospectively planned.

Results: The entire and the investigated study populations did not differ regarding baseline characteristics. After median follow up of 64 months, both DFS (5y 90% vs. 80%, p=0.006) and OS (5y 95% vs. 92%, p=0.022) rates significantly favored EC-Doc vs. CEF in this cohort as well. HER2 over-expression (3+ and/or FISH≥2.0) was reported in 158 tumors (20%), Topo-II aberration (deletion or amplification) was reported in 78 (49.4%) HER2+ and in 83 (13.6%) HER2−negative tumors; 496 tumors were classified as TIMP-1 immunoreactive (65.2%). None of these factors were significantly prognostic for EFS in this collective. Regarding DFS, EC-Doc was strongly superior to FEC in HER2+ tumors (HR=0.29, 95%CI: 0.12−0.7, p=0.006) but not in HER2− tumors (p=0.18). In Topo-II aberrated tumors, the benefit of EC-Doc was remarkably strong (HR=0.28, 95% CI: 0.11−0.69, p=0.006), whereas the benefit was not significant in Topo-II normal tumors (p=0.16), which comprise more than ¾ of the total. In contrast, Topo-II protein overexpression (&gt;10%) was not associated with a stronger benefit in either subgroup. The superiority of EC-Doc to FEC was significant in the larger group of TIMP-1 immunoreactive tumors (HR=0.57, p=0.025) but not in TIMP-1 negative tumors (p=0.14), similar behavior was seen in “HT” and “2T” subgroups (significance with HR about 0.5 in the “+” subgroups). In a multivariate model for DFS including age, tumor size, Ki-67, central grade, HR, HER2, TOPO_II aberration, TIMP-1 status, therapy and interactions of all these factors with therapy arm, the only significant therapy interaction was that of (high) Ki-67 (HR=0.76, 95% CI: 0.59−0.98, p=0.03); significant main effects in this model were age, central grade, and Ki-67.

Conclusions: These data suggest predictive significance for Topo-II aberration, TIMP immunoreactivity and HER2 over-expression as well as a multivariate predictive significance of high Ki-67 for enhanced benefit of taxane-based cht.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-06-03.

PD03-02: Prognostic and Predictive Predictors for Triple Negative Breast Cancer

Background: Both the prognosis and the therapeutic options in triple negative breast cancer (TNBC) are rather limited. Current prognostic gene expression profiles for breast cancer mainly reflect proliferation status and are most useful in ER-positive cancers. The identification of prognostic gene signatures from TNBC cohorts in previous studies was hindered due to relatively small sample sizes.

Materials and Methods: All currently available TNBC gene expression datasets generated on Affymetrix U133 gene chips were assembled. To minimize inter-laboratory variation we analyzed only highly comparable arrays and data set-biased genes were filtered. Supervised analysis was applied to identify a prognostic signature from a finding cohort of 394 TNBC and validation was performed in an independent cohort of 261 TNBC. The genes from the prognostic predictor were analyzed for their correlation to known molecular phenotypes among TNBC.

Results: Two supervised prognostic signatures consisting of 264 and 26 probesets, respectively, were obtained when applying different cutoffs for false discovery rates of 25% and &lt; 3.5% in the finding cohort. In multivariate analysis in the independent validation cohort hazard ratios of 4.03 (95% CI 1.71−9.48; P=0.001) and 4.08 (95% CI 1.79−9.28; P=0.001), respectively, were obtained for the two signatures. When compared to 16 metagenes for previously described molecular phenotypes in TNBC the prognostic signatures displayed highest correlation to metagenes for IL-8/inflammation, VEGF/angiogenesis, and Histones. A subset of genes in the 264-probeset signature was inversely associated with a poor prognosis (29/264=11.0%). Most of these “good prognosis” genes are correlated with immune cell metagenes (21/29=72.4%). In contrast both identified supervised prognostic signatures did not correlate to previously published prognostic signatures (recurrence score, genomic grade index, Amsterdam signature, wound response signature, 7-gene immune response module, stroma derived prognostic predictor, and a medullary like signature). Regarding the response of TNBC to neoadjuvant chemotherapy the predictive value of the B-cell metagene was superior to the 264- and 26-probeset signatures. However combination of the B-cell metagene and the signatures increased the AUC in ROC-analysis from 0.606 to 0.656. Conclusions: The use datasets consisting only of TNBC allows identification supervised prognostic signatures for TNBC which are unrelated to previously known prognostic signatures.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD03-02.