OS01.5.A Neuron-specific enolase (NSE) and S100 serum levels in patients with active brain metastases from HER2-positive breast cancer treated with trastuzumab-deruxtecan (T-DXd): A biomarker analysis from the TUXEDO-1 trial

Background

T-DXd is a novel antibody-drug conjugate with high activity in HER2-positive metastatic breast cancer. The prospective, single-arm, single-centre phase II TUXEDO-1 trial showed clinically relevant activity of T-DXd in HER2-positive BC pts with active BM with an intracranial response rate of 73.3%. This biomarker sub-study of TUXEDO-1 aimed to investigate changes in the extent of metastases-induced brain damage in patients with and without response to therapy by measuring the serum levels of two proteins constitutively expressed in the human brain and measurable upon brain damage in the blood serum: NSE and S100.

Material and Methods

We assessed serum NSE (sNSE) and serum S100 (sS100) levels in a total of 37 blood samples drawn at cycles 1, 4 and end of treatment (EOT) in all patients of the intent-to-treat population of the TUXEDO-1 trial using commercially available ELISA assays. Intracranial radiological response was centrally assessed by a board-certified neuro-radiologist using RANO criteria. sNSE and sS100 levels were compared between responders and non-responders using the Mann Whitney U test and a significance level of 0.05.

Results

At baseline, we detected no significant difference of sNSE or sS100 levels between T-DXd responders and non-responders, respectively. Baseline median sNSE level was 10.6 ng/ml (interquartile range (IQR) 8.6-12.2) in T-DXd responders as compared with median 12.5 ng/ml (IQR 12.2-12.9) in the non-responder group (n.s.). At cycle 4, corresponding numbers were 8.1 ng/ml in responding patients (IQR 7-11.2) and 12.7 ng/ml (IQR 12.2-12.9) in non-responders, respectively (p=0.009). No differences in sS100 levels were observed between the groups at any time point.

Conclusion

In patients showing intracranial objective response to T-Dxd, sNSE levels were significantly lower at cycle 4 as compared with non-responders, suggesting a reduction in metastases-induced brain damage as a direct treatment effect. sNSE may be a clinically useful biomarker for longitudinal assessment of brain metastasis burden.

A clinical validation study of MammaPrint in hormone receptor-positive breast cancer from the Austrian Breast and Colorectal Cancer Study Group 8 (ABCSG-8) biomarker cohort

Background

MammaPrint is a prognostic assay based on gene expression in tumors from patients with early breast cancer. MammaPrint has been extensively validated and Food and Drug Administration cleared in fresh and formalin-fixed and paraffin-embedded (FFPE) tissue. We aimed to assess its prognostic performance in the biomarker cohort of the Austrian Breast and Colorectal Cancer Study Group 8 (ABCSG-8) patient population, and to obtain a higher level of evidence with regard to its clinical validity after RNA extraction from FFPE biobank tissue.

Patients and methods

A prespecified retrospective analysis to test the prognostic performance of the MammaPrint test to predict distant recurrence-free survival at 5 and 10 years as primary end point was carried out. MammaPrint risk, clinicopathological factors (after central pathological review), and clinical risk (using a modified version of Adjuvant! Online) were evaluated by Cox regression analyses.

Results

From 1347 available samples, 607 (45%) failed quality control after RNA extraction. In total, 658 (49%) patients were included in survival analyses: MammaPrint low risk versus high risk is a significant prognostic factor for distant recurrence-free survival at 5 years (94.0% versus 91.6%) with a significant risk reduction of 6.5% at 10 years (log-rank P value = 0.017, low risk 91.3% versus high risk 84.8%). The multivariable models suggest that hazard ratio (HR) is primarily driven by tumor stage (5-year HR 3.89; confidence interval 1.97-7.71) and nodal status (5-year HR 1.73; confidence interval 0.91-3.21). After adjustment for clinical risk groups, MammaPrint HRs remain stable with values just below 2.0 after the first 3 years.

Conclusions

The MammaPrint test showed significant prognostic performance at 5 and 10 years of follow-up. In the particular cohort of ABCSG-8, the statistical independence from clinically assessed covariates remains unclear, and no conclusions concerning the clinical validity of the test can be drawn.

•

MammaPrint is a prognostic assay based on gene expression in tumors from patients with early breast cancer.

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MammaPrint has been extensively and successfully validated- but mostly in fresh tissue.

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We aimed to assess its prognostic performance in FFPE tissue from the ABCSG 8 biomarker cohort.

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The MammaPrint test showed significant prognostic performance at 5 and 10 years of follow-up.

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The statistical independence from clinically assessed covariates is unclear- the clinical validity in ABCSG 8 uncertain.

Impact of Surgical Margins in Breast Cancer After Preoperative Systemic Chemotherapy on Local Recurrence and Survival

Background

While “no tumour on ink” is an accepted margin width for R₀ resection in primary surgery, it’s unclear if it’s oncologically safe after neoadjuvant chemotherapy (NAC). Only limited data demonstrate that surgery within new margins in cases of a pathological complete response (pCR) is safe. We therefore investigated the influence of different margins and pCR on local recurrence and survival rates after NAC.

Methods

We retrospectively analysed data of 406 women with invasive breast cancer, treated with NAC and breast-conserving therapy between 1994 and 2014 in two certified Austrian breast health centres. We compared R ≤ 1 mm, R > 1 mm and RX (pCR) for local recurrence-free survival (LRFS), disease-free survival (DFS) and overall survival (OS).

Results

After a median follow-up of 84.3 months, the 5-year LRFS (R ≤ 1 mm: 94.2%, R > 1 mm: 90.6%, RX: 95.0%; p = 0.940), the 5-year DFS (R ≤ 1 mm: 71.9%, R > 1 mm: 74.1%, RX: 87.2%; p = 0.245) and the 5-year OS (R ≤ 1 mm: 85.1%, R > 1 mm: 88.0%, RX: 96.4%; p = 0.236) did not differ significantly between narrow, wide, nor RX resections. Regarding DFS and OS, a negative nodal status reduced the hazard ratio significantly.

Conclusion

There is no significant difference in LRFS, DFS and OS comparing close, wide or unknown margins after pCR. We suggest that resection in new margins after NAC is safe according to “no tumour on ink”. Resection of the clipped area in cases of pCR is emphasized.

Abstract P4-08-05: Prediction of distant recurrence using EndoPredict among women with ER-positive, HER2-negative breast cancer with a maximum follow-up of 16 years

Background: EndoPredict has been previously validated as a prognostic test in women with ER-positive, HER2-negative disease who received endocrine therapy only as part of the ABCSG6 and -8 trials. Here, we further evaluate the prognostic value of EndoPredict in this cohort with longer-term follow-up and compare 10-year distant recurrence (DR) and 5-15 years late recurrence according to nodal status.

Methods: This analysis included 1702 patients with ER-positive, HER2-negative disease who received endocrine therapy only. Prognostic value of EPclin score and EPclin risk category (high, low) on the risk of distant recurrence adjusted for patient and disease characteristics was evaluated using multivariable Cox proportional hazard models. Kaplan-Meier estimators were used to estimate DR according EPclin class and were compared using log rank test. Analyses were performed for the overall cohort, by nodal status, and for patients who were distant recurrence free at year 5 (late recurrence).

Results: The median follow-up was 9.6 years (range 0-16.6), an increase of 4.2 years over previous reports. Reanalysis with longer follow-up confirms that EPclin is a significant predictor of DR after adjusting for clinical factors, regardless of nodal status (Table 1). Overall, 62.6% of patients had low risk EPclin scores and 10-year DR was significantly improved relative to those with high risk scores (p<0.0001; Table 2). When nodal status was considered, 77.8% of node negative tumors and 34.9% of node positive (1-3 PLN) tumors had low risk EPclin scores. Regardless of nodal status, DR was significantly improved for those with low versus high risk EPclin scores (Table 2). Similar results were observed for the patients who were DR free at year 5 (5-15 year follow-up) (Table 2).

Conclusion: This reanalysis of previous EndoPredict data with a longer follow-up confirms that EPclin can identify a large group of patients at low risk of distant recurrence after 10 years who might be sufficiently treated with 5 years adjuvant endocrine therapy only, independent of nodal status. Replication of these results for the late distant recurrence between years 5-15 also shows that EPclin scores may also be informative in selecting patients who may safely forgo extended endocrine therapy.

Table 1.Multivariate analysis 0-15 year DR5-15 year DRCohortHR*p-valueHR*p-valueAll patients2.55<0.00012.56<0.0001Node negative1.680.00352.010.00881-3 positive nodes2.68<0.00013.430.0004*Hazard Ratio (HR) per unit score after adjusting for age, tumor grade, Ki67, ER, PR, and treatment

Table 2.DR according to EPclin score  Low risk EPclinHigh risk EPclin CohortHR*%0-10 year DR (95% CI)%0-10 year DR (95% CI)Log-rank p-valueAll patients N=17024.7762.60.96 (0.94, 0.97)37.40.80 (0.77, 0.84)<0.0001Node negative N=11653.4777.80.96 (0.94, 0.97)22.20.87 (0.83, 0.92)<0.00011-3 positive nodes N=4533.6534.90.96 (0.92, 0.99)65.10.81 (0.76, 0.87)0.0003CohortHR*%5-15 year DR (95% CI)%5-15 year DR (95% CI)Log-rank p-valueAll patients N=13864.5264.70.96 (0.93, 0.98)35.30.84 (0.79, 0.90)<0.0001Node negative N=9753.7678.30.97 (0.95, 0.99)21.70.85 (0.75, 0.96)<0.00011-3 positive nodes N=3623.0036.50.87 (0.72, 1.00)63.50.84 (0.77, 0.92)0.0337*HR for EPclin high risk versus low risk

Citation Format: Filipits M, Dubsky P, Rudas M, Greil R, Balic M, Fitzal F, Bago-Horvath Z, Singer C, Hlauschek D, Kronenwett R, Bernhisel R, Lancaster J, Gnant M. Prediction of distant recurrence using EndoPredict among women with ER-positive, HER2-negative breast cancer with a maximum follow-up of 16 years [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 P4-08-05.

Abstract P1-17-05: The impact of clinical risk assessment versus PAM-50 ROR score on prognosis and therapeutic decision making in patients with hormone-receptor positive early stage breast cancer

Background: Therapeutic recommendations for adjuvant treatment of hormone-receptor positive breast cancer patients depend on the individual recurrence risk. A number of genomic assays introduced to achieve this goal, but it's still questioned if they actually offer superior risk assessment compared to traditional risk evaluation by experienced clinicians. This study was designed to compare the prognostic accuracy of PAM-50 to clinical judgment.

Methods: Based on the real data of a large adjuvant trial cohort (ABCSG-8, postmenopausal HR positive breast cancer patients), we created online-questionnaires including demographic, histological, and local-therapy details, with and without results of PAM50 ROR score. Out of 14 international breast cancer experts asked for individual patient's risk evaluation (low, intermediate, high) and therapy recommendations, 9 completed the questionnaire.

Patient data were described by Kaplan-Meier estimates of distant disease free survival (DDFS) stratified by risk group. Cox regression models were compared using the Akaike Information Criterion (AIC).

Results: 10 years DDFS and hazard ratios for distant recurrences stratified by risk-group as estimated giving in Table 1:

10 years DDFS and hazard ratios for distant recurrences stratified by risk-group as estimated Low riskIntermediate riskHigh risk n (%)10y DDFS,%(95%CI)n (%)10y DDFS,%(95%CI)n (%)10y DDFS, %(95%CI)  HR(95% CI) HR(95% CI) HR(95% CI)Clinical only: AIC 817.6269 (43)93.0(89.8-96.2)289 (46)89.7(85.9-93.5)73 (11)76.6(66.1-87.1)  0.68(0.39,1.20) 1 2.57(1.41,4.65)PAM50 ROR: AIC 804.8241 (34)96.5(93.1-99.1)210 (33)89.2(84.7-93.7)207 (33)82.5(76.9-88.2)  0.27(0.11,0.62) 1 1.66(0.99,2.78)Combined: AIC 813.4232 (37)95.7(93.0-98.5)282 (45)87.8(83.7-92.0)117 (18)81.7(74.2-89.2)  0.42(0.22,0.84) 1 1.90(1.11,3.24)

Adding genomic information to clinical risk factors leads to escalation of therapeutic recommendations (i.e. additional chemotherapy, extended adjuvant endocrine) in 20% of patients, and de-escalation in 13% of patients.

Conclusions: Clinical judgment accurately identified the patients at high risk of relapse, but was clearly inferior to multi-genomic testing using the PAM-50 ROR score in differentiating low from intermediate risk. Particularly when avoiding unnecessary escalated therapy is the strategic goal, the addition of PAM-50 testing to clinical judgment offers improved accuracy in predicting low vs. intermediate risk of breast cancer recurrence.

Citation Format: Devyatko Y, Filipits M, Greil R, Balic M, Bago-Horvath Z, Singer C, Fitzal F, Steger G, Gray B, Ferree S, Fesl C, Soelkner L, von Minckwitz G, Gnant M. The impact of clinical risk assessment versus PAM-50 ROR score on prognosis and therapeutic decision making in patients with hormone-receptor positive early stage breast cancer [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 P1-17-05.

Abstract P6-10-01: Efficacy and safety of the therapeutic cancer vaccine tecemotide (L-BLP25) in early breast cancer: Results from a prospective, randomized, neoadjuvant phase-II study (ABCSG-34)

Background: Immune-based therapeutic strategies represent a promising approach in early and advanced breast cancer treatment. MUC1 glycoprotein is overexpressed and aberrantly glycosylated in over 90% of malignant breast cancer. It is involved in oncogenesis and confers resistance to anti-cancer therapies, thus representing a particularly promising target. Tecemotide is a MUC1-based therapeutic cancer vaccine. The aim of this trial was to investigate the efficacy and safety of preoperative tecemotide in primary breast cancer patients receiving neoadjuvant Standard-of-Care (SoC) treatment.

Patients and Methods: 400 patients with HER2-negative early breast cancer were recruited into this prospective, multicentre randomized 2-arm academic phase-II trial. Patients received preoperative SoC treatment with or without tecemotide therapy. Postmenopausal women with E+++, or E++ and Ki67 <14%, and G1,2,X tumors received 6 months of letrozole as SoC. Postmenopausal patients with triple-negative, E- or E+, or E++ and Ki67 ≥14%, and with G3 tumors, and all premenopausal patients received 4 cycles of epirubicin/cyclophosphamide plus 4 cycles of docetaxel as SoC. Patients were additionally randomized to receive reverse or conventional sequence of epirubicin/cyclophosphamide and docetaxel. Primary endpoint was histopathological response measured by Residual Cancer Burden (RCB0/I vs RCBII/III) at the time of surgery. Secondary endpoints included pCR, efficacy of reverse versus conventional sequence chemotherapy, and safety.

Results: We did not observe a significant difference in RCB0/I rates between patients with (36.4%) and without (31.9%) tecemotide in the overall study population (p = 0.40), and in endocrine and chemotherapy treated subgroups (25.0% vs 13.3%, p = 0.17; 39.6% vs 37.8%, p = 0.75). Similarly, addition of tecemotide did not affect overall pCR rates (22.5% vs 17.4%, p = 0.23). RCB0/I rates were comparable regardless of docetaxel being given before or after epirubicin/cyclophosphamide (37.2% vs 40.1%, p = 0.61). Tecemotide addition was not associated with a worse toxicity profile (178 AEs, 57 SAEs vs 180 AEs, 48 SAEs based on patient incidence).

Conclusion: Immune-based targeting of MUC1 by tecemotide is safe but does not improve RCB and pCR rates in early SoC-treated breast cancer.

Citation Format: Singer CF, Pfeiler G, Hubalek M, Bartsch R, Stoeger H, Pichler A, Petru E, Greil R, Rudas M, Tea M-KM, Wette V, Petzer AL, Sevelda P, Egle D, Dubsky PC, Balic M, Tinchon C, Bago-Horvath Z, Frantal S, Michael G. Efficacy and safety of the therapeutic cancer vaccine tecemotide (L-BLP25) in early breast cancer: Results from a prospective, randomized, neoadjuvant phase-II study (ABCSG-34) [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 P6-10-01.

Abstract P1-09-10: Pathological complete response to neoadjuvant trastuzumab is dependent on HER2/CEP17 ratio in HER2-amplified early breast cancer

Purpose To evaluate whether pathological complete response to neoadjuvant trastuzumab is dependent on the level of HER2 amplification.

Patients and Methods 114 women with HER2-overexpressing early breast cancer who had received neo-adjuvant trastuzumab in the prospective ABCSG-24 and ABCSG-32 trials, and for whom the HER2/CEP17 ratio was available, were included in this analysis. The ratio was correlated with tumor response as measured by the three most commonly used definitions of pathological complete response: ypT0 ypN0, ypT0/is ypN0, and ypT0/is.

Results In trastuzumab-treated patients, ypT0 pN0 was achieved in 69.0% of patients with a HER2/CEP17 ratio of >6, but only in 30.4% of tumors with a ratio of ≤6 (p=0.001, Chi Square test). When pCR was defined by ypT0/is pN0 or by ypTis, 75.9% and 82.8% of tumors with a high ratio had a complete remission, while only 39.1%, and 38.3% with a low ratio achieved a pCR (p=0.002 and p<0.001, respectively). Logistic regression revealed that tumors with a higher HER2/CEP17 ratio had a significantly higher probability to achieve ypT0 ypN0 (OR: 5.08, 95% CI 1.86-13.90; p=0.002) than tumors with a low ratio, while none of the other clinicopathological parameters was predictive of pCR. The association between high HER2 amplification and pCR was almost exclusively confined to HR positive tumors (62.5% vs. 24.0%, 75.0% vs. 28.0%, and 87.5% vs. 28.0%, for ypT0 ypN0, ypT0/is ypN0, and ypT0/is; p=0.014, p=0.005, and p<0.001), and was largely absent in HR negative tumors.

Conclusion A HER2/CEP17 ratio of >6 in the pre-therapeutic tumor biopsy is associated with a significantly higher pCR rate particularly in HER2 / HR co-positive tumors, and can be used to predict outcome before neoadjuvant trastuzumab is initiated.

Citation Format: Singer CF, Tan YY, Fitzal F, Steger GG, Egle D, Reiner A, Rudas M, Gruber C, Bartsch R, Fridrik M, Seifert M, Exner R, Balic M, Bago-Horvath Z, Filipits M, Gnant M, For the Austrian Breast and Colorectal Cancer Study Group. Pathological complete response to neoadjuvant trastuzumab is dependent on HER2/CEP17 ratio in HER2-amplified early 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 P1-09-10.

Prognostic impact of breast cancer subtypes in elderly patients

We aimed to analyse the impact of breast cancer (BC) subtypes on the clinical course of disease with special emphasis on the occurrence of brain metastases (BM) and outcome in an elderly BC population. A total number of 706 patients ≥65 years receiving treatment for BC from 2007 to 2011 were identified from a BC database. 62 patients diagnosed with DCIS and 73 patients with incomplete datasets were excluded, leaving 571 patients for this analysis. Patient characteristics, biological tumour subtypes, and clinical outcome including overall survival (OS) were obtained by retrospective chart review. 380/571 (66, 5 %) patients aged 65–74 years were grouped among the young-old, 182/571 (31.9 %) patients aged 75–84 years among the old–old, and 29/571 (5.1 %) patients aged ≥85 years among the oldest-old. 392/571 (68.8 %) patients presented with luminal BC, 119/571 (20.8 %) with HER2-positive, and 59/571 (10.3 %) with triple-negative BC (TNBC). At 38 months median follow-up, 115/571 (20.1 %) patients presented with distant recurrence. A higher recurrence rate was observed in the HER2-positive subtype (43/119 (36.1 %)), as compared to TNBC (15/59 (25.4 %)) and luminal BC (57/392 (14.5 %); p < 0.001). BM were detected at a significantly higher rate in HER2-positive BC patients (9/119 (7.6 %)), as compared to TNBC (2/59 (3.4 %)) and luminal BC patients (6/392 (1.5 %); p = 0.003). Diagnosis of metastatic disease (HR 7.7; 95 % CI 5.2–11.4; p < 0.001) as well as development of BM (HR 3.5; 95 % CI 1.9–6.4; p < 0.001) had a significantly negative impact on OS in a time-dependent covariate cox regression model. In contrast to younger BC patients, outcome in this large cohort of elderly patients suggests that HER2-positive disease—not TNBC—featured the most aggressive clinical course with the highest rates of metastatic spread and BM. In-depth analysis regarding a potentially distinct biology of TNBC in elderly is therefore warranted.

Abstract P2-08-17: Prognostic impact of breast cancer subtypes in elderly patients

Background

We aimed to analyze the impact of BC subtypes on the clinical course with special emphasis on the occurrence of brain metastases (BM) and outcome in an elderly breast cancer population.

Patients and Methods

571 patients ≥65 years receiving treatment for BC from 2007-2011 were identified from a BC database. BC subtypes and clinical characteristics including overall survival (OS) were obtained by chart review. Statistical analysis was performed using the Chi Square test, the log rank test and time depended covariate cox regression model as appropriate.

Results

Three-hundred-eighty/571 (63%) were grouped among the young-old (65-74 years), 182/571 (31.9%) among the old-old (75-84 years), and 29/571 (5,1%) among the oldest-old (≥85 years). 392/571 (68.8%) patients presented with luminal BC, 119/571 (20.8%) with HER2 positive and 59/571 (10.3%) with triple negative BC. After a median follow up of 38 months (range 0-204), 115/571 (20.1%) patients presented with metastatic recurrence. Highest recurrence rate was observed in HER2 positive BC patients (43/119 (36.1%)), followed by triple negative (15/59 (25.4%) and luminal BC (57/392 (14.5%); p&lt;0.001; Chi Square test). BM occurred significantly more frequently in HER2 positive BC patients (9/119 (7.6%) compared to triple negative (2/59 (3.4%) and luminal BC patients (6/392 (1.5%); p=0.003; Chi Square test). Occurrence of metastases (HR 7.7; 95% CI 5.2-11.4; p&lt;0.001) as well as development of BM (HR 3.5; 95% CI 1.9-6.4; p&lt;0.001) had a significant impact on OS prognosis as entered in a time depended covariate cox regression model.

Conclusions

In contrast to younger BC patients, HER2 positive BC subtype and not triple negative BC subtype was linked to the most aggressive clinical course including the development of metastatic disease and BM in our elderly cohort.

Citation Format: Bergen ES, Tichy C, Berghoff AS, Rudas M, Dubsky P, Bago-Horvath Z, Mader RM, Gnant M, Dieckmann K, Zielinski CC, Steger GG, Preusser M, Bartsch R. Prognostic impact of breast cancer subtypes in elderly patients. [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 P2-08-17.

The multigene signature MammaPrint impacts on multidisciplinary team decisions in ER+, HER2- early breast cancer

Background:

Validated multigene signatures (MGS) provide additional prognostic information when evaluating clinical features of ER⁺, HER2⁻ early breast cancer. We have studied the quantitative and qualitative impact of MGS on multidisciplinary team (MDT) recommendations.

Methods:

We prospectively recruited 75 ER⁺, HER2⁻ breast cancer patients. Inclusion was based on biopsy assessment of grade, hormone receptor status, HER2, clinical tumour and nodal status. A fresh tissue sample was sent for MammaPrint (MP), TargetPrint analysis at surgery. Clinical risk was decided by the MDT in the absence of MP results and repeated following the collection of MP results. Decision changes were recorded and a health technology assessment was undertaken to compare cost effectiveness.

Results:

The majority of patients were assigned low to intermediate clinical risk by the MDT. According to MP, 76% were low risk. A very high correlation between local IHC and the TargetPrint assessment was shown. In over a third of patients, discordance between clinical and molecular risk was observed. Decision changes were recorded in half of these cases (18.6%) and resulted in two out of three patients not requiring chemotherapy. The use of MP was also found to be more cost effective.

Conclusions:

The multigene signature MP revealed clinical and molecular risk discordance in a third of patients. The impact of this on MDT recommendations was most profound in cases where few clinical risk factors were observed and enabled some women to forgo chemotherapy. The use of MGS is unlikely to have an impact in either clinically low-risk women or in patients with more than one relative indication for chemotherapy.

Predicting distant recurrence in receptor-positive breast cancer patients with limited clinicopathological risk: using the PAM50 Risk of Recurrence score in 1478 postmenopausal patients of the ABCSG-8 trial treated with adjuvant endocrine therapy alone

BACKGROUND

PAM50 is a 50-gene test that is designed to identify intrinsic breast cancer subtypes and generate a Risk of Recurrence (ROR) score. It has been developed to be carried out in qualified routine hospital pathology laboratories.

PATIENTS AND METHODS

One thousand four hundred seventy-eight postmenopausal women with estrogen receptor (ER)+ early breast cancer (EBC) treated with tamoxifen or tamoxifen followed by anastrozole from the prospective randomized ABCSG-8 trial were entered into this study. Patients did not receive adjuvant chemotherapy. RNA was extracted from paraffin blocks and analyzed using the PAM50 test. Both intrinsic subtype (luminal A/B, HER2-enriched, basal-like) and ROR score were calculated. The primary analysis was designed to test whether the continuous ROR score adds prognostic value in predicting distant recurrence (DR) over and above standard clinical variables.

RESULTS

In all tested subgroups, ROR score significantly adds prognostic information to the clinical predictor (P<0.0001). PAM50 assigns an intrinsic subtype to all cases, and the luminal A cohort had a significantly lower ROR at 10 years compared with Luminal B (P<0.0001). Significant and clinically relevant discrimination between low- and high-risk groups occurred also within all tested subgroups.

CONCLUSION(S)

The results of the primary analysis, in combination with recently published results from the ATAC trial, constitute Level 1 evidence for clinical validity of the PAM50 test for predicting the risk of DR in postmenopausal women with ER+ EBC. A 10-year metastasis risk of <3.5% in the ROR low category makes it unlikely that additional chemotherapy would improve this outcome-this finding could help to avoid unwarranted overtreatment.

CLINICAL TRIAL NUMBER

ABCSG 8: NCT00291759.

Abstract P1-08-13: Predictive value of intrinsic luminal subtypes in premenopausal women with endocrine-responsive early breast cancer: Results from Austrian breast and colorectal cancer study group trial 5

Purpose: The aim of the present study was to assess the predictive value of intrinsic luminal subtypes in premenopausal hormone receptor-positive early breast cancer patients who received adjuvant endocrine treatment or chemotherapy.

Patients and Methods: Intrinsic luminal breast cancer subtypes were centrally assessed by immunohistochemistry on whole tissue sections of breast cancer patients who had been enrolled in the Austrian Breast and Colorectal Cancer Study Group (ABCSG) Trial 5 and received either 3 years of goserelin plus 5 years of tamoxifen or six cycles of cyclophosphamide, methotrexate, and fluorouracil (CMF). Luminal A disease was defined as Ki67 &lt;20%, Luminal B/HER2-negative subtype as Ki67≥20%. Luminal B/HER2-positive subtype displayed HER2 overexpression by IHC or amplification by ISH. Recurrence-free survival (RFS) and overall survival (OS) were analyzed using Cox models adjusted for clinical and pathological factors.

Results: 155 (36%), 217 (50%) and 59 (14%) of 431 tumors were classified as Luminal A, Luminal B/HER2-negative and Luminal B/HER2-positive, respectively. Luminal B subtypes were associated with poor outcome. Patients with Luminal B tumors had a significantly shorter RFS (adjusted hazard ratio [HR] for recurrence: 2.29, 95% confidence interval [CI] 1.44-3.64, P &lt; 0.001) and OS (adjusted HR for death: 3.97, 95% CI 1.94-8.08, P &lt; 0.001) as compared to patients with Luminal A disease. No interaction between intrinsic luminal subtypes and treatment was observed (test for interaction: P = 0.42 for RFS; P = 0.32 for OS). Combination endocrine treatment with goserelin/tamoxifen tended to be more effective than CMF chemotherapy in both luminal A and luminal B subtypes.

Conclusion: Intrinsic luminal subtype is an independent prognostic factor for recurrence and death in premenopausal women with early-stage, hormone receptor positive breast cancer but is not predictive for outcome of adjuvant treatment with either goserelin/tamoxifen or chemotherapy with CMF.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-08-13.

Brain-only metastatic breast cancer is a distinct clinical entity characterised by favourable median overall survival time and a high rate of long-term survivors

BACKGROUND

The clinical course of breast cancer patients with brain metastases (BM) as only metastatic site (brain-only metastatic breast cancer (BO-MBC)) has been insufficiently explored.

METHODS

All breast cancer patients with BM treated at our institution between 1990 and 2011 were identified. For each patient, full information on follow-up and administered therapies was mandatory for inclusion. Oestrogen receptor, progesterone receptor and Her2 status were determined according to standard protocols. Statistical analyses including computation of survival probabilities was performed.

RESULTS

In total, 222 female patients (26% luminal; 47% Her2; 27% triple negative) with BM of MBC were included in this study. In all, 38/222 (17%) BM patients did not develop extracranial metastases (ECM) during their disease course and were classified as BO-MBC. Brain-only-MBC was not associated with breast cancer subtype or number of BM. The median overall survival of BO-MBC patients was 11 months (range 0-69) and was significantly longer than in patients with BM and ECM (6 months, range 0-104; P=0.007). In all, 7/38 (18%) BO-MBC patients had long-term survival of >3 years after diagnosis of BM and long-term survival was significantly more common in BO-MBC patients as compared with BM patients with ECM (P<0.001).

CONCLUSIONS

Brain-only metastatic behaviour occurs in around 17% of breast cancer with BM and is not associated with breast cancer subtype. Exploitation of all multimodal treatment options is warranted in BO-MBC patients, as these patients have favourable prognosis and long-term survival is not uncommon.

Brain metastases free survival differs between breast cancer subtypes

BACKGROUND

Brain metastases (BM) are frequently diagnosed in patients with HER-2-positive metastatic breast cancer; in addition, an increasing incidence was reported for triple-negative tumours. We aimed to compare brain metastases free survival (BMFS) of breast cancer subtypes in patients treated between 1996 until 2010.

METHODS

Brain metastases free survival was measured as the interval from diagnosis of extracranial breast cancer metastases until diagnosis of BM. HER-2 status was analysed by immunohistochemistry and reanalysed by fluorescent in situ hybridisation if a score of 2+ was gained. Oestrogen-receptor (ER) and progesterone-receptor (PgR) status was analysed by immunohistochemistry. Brain metastases free survival curves were estimated with the Kaplan-Meier method and compared with the log-rank test.

RESULTS

Data of 213 patients (46 luminal/124 HER-2/43 triple-negative subtype) with BM from breast cancer were available for the analysis. Brain metastases free survival differed significantly between breast cancer subtypes. Median BMFS in triple-negative tumours was 14 months (95% CI: 11.34-16.66) compared with 18 months (95% CI: 14.46-21.54) in HER-2-positive tumours (P=0.001) and 34 months (95% CI: 23.71-44.29) in luminal tumours (P=0.001), respectively. In HER-2-positive patients, co-positivity for ER and HER-2 prolonged BMFS (26 vs 15 m; P=0.033); in luminal tumours, co-expression of ER and PgR was not significantly associated with BMFS. Brain metastases free survival in patients with lung metastases was significantly shorter (17 vs 21 months; P=0.014).

CONCLUSION

Brain metastases free survival in triple-negative breast cancer, as well as in HER-2-positive/ER-negative, is significantly shorter compared with HER-2/ER co-positive or luminal tumours, mirroring the aggressiveness of these breast cancer subtypes.

P4-17-05: Brain Metastasis Free Survival (BMFS) Differs between Breast Cancer Subtypes

BACKGROUND Brain metastases (BM) are frequently diagnosed in patients (pts) with Her2-positive metastatic breast cancer (BC); a rising incidence was also reported in triple-negative disease. We hypothesized that pts with triple-negative or Her2-positive tumours had shorter BMFS as compared to other BC subtypes.

Therefore, we aimed to compare BMFS in pts with Her2-positive, estrogen receptor (ER) positive and triple-negative BC treated at the Medical University of Vienna from 1999–2009. In Her2-positive tumours, we further investigated the influence of ER co-expression on BMFS, as Her2-positive / ER-positive tumours were reported to express less aggressive biological properties.

METHODS BMFS was defined as primary study endpoint and measured as the interval from diagnosis of metastatic BC until diagnosis of BM. A total of 168 pts were identified from a breast cancer database. 34 pts were excluded from this analysis as brain was the first site of disease progression; hence complete datasets from 134 pts were available (69 Her2-positive; 33 triple-negative; 32 ER-positive).

Her2 status was analyzed by immunohistochemistry (IHC) and reanalyzed by FISH if a score of 2+ was gained. ER was analyzed by IHC; ER negative tumours were defined by a cut-off value of &lt;10% positively stained tumour cells. BMFS was estimated with the Kaplan-Meier product limit method and compared with the log-rank test; factors significantly associated with BMFS in the univariate analysis were included into a Cox proportional hazard model.

RESULTS Median BMFS in triple-negative pts was 14 months (m) (95% CI 12.17−15.83), as compared to 25 m (95% CI 13.37−36.62) in Her2-positive (p=0.001) and 35 m (95% CI 19.79−50.22) in ER-positive pts (p&lt;0.001), respectively.

In Her2-positive pts, prior trastuzumab treatment for metastatic disease prolonged median BMFS (29 vs. 11 m; p&lt;0.001); BMFS was further improved by trastuzumab in multiple lines (p=0.045) and co-positivity for ER and Her2 (30 vs. 15 m; p&lt;0.001).

ER-expression (HR 2.03; 95%CI 1.22−3.36; p&lt;0.05) and prior trastuzumab (HR 2.72; 95%CI 1.20−6.17; p=0.017) remained independent predictors of longer BMFS in the Cox regression model. In ER-positive, triple-negative as well as Her2-positive pts, no correlation was found between BMFS and factors such as grading, histological subtype, stage IV disease at primary diagnosis, disease-free interval &lt;24 months from primary treatment to diagnosis of metastatic disease, presence of visceral metastases, presence of lung metastases, and prior capecitabine exposure.

CONCLUSIONS BMFS in triple-negative disease is significantly shorter as compared to Her2-positive or ER-positive tumours, mirroring the aggressiveness of this breast cancer subtype. Probably due to improved systemic disease control, trastuzumab significantly prolonged BMFS in Her2-positive pts. Longer BMFS in ER/Her2 co-positive disease reflects a less aggressive subtype of Her2-positive breast cancer which is less likely to benefit from strategies of BM screening or prevention.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-17-05.

Brain metastasis-free survival in patients with HER2-positive metastatic breast cancer

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Background: Brain metastases (BM) are diagnosed in up to 40% of patients with HER2-positive metastatic breast cancer (MBC). Since the introduction of trastuzumab in 1999, a rising incidence of BM was reported. We aimed to identify factors that prolong BM free survival (BMFS) in all HER2-positive patients (pts) treated for MBC at the Medical University of Vienna from 1999-2009.

Methods: BMFS was defined as primary study endpoint and measured as the interval from diagnosis of metastatic disease until diagnosis of brain metastases. 201 pts with HER2-positive MBC were identified from a breast cancer database. 82 pts (40.8%) were diagnosed with BM; 13 pts were excluded from this analysis as brain was the first site of disease progression. Complete data sets of 69 pts with pathologically verified HER2-positive MBC were available. HER2 status was analyzed by immunohistochemistry and reanalyzed by FISH if a score of 2= was gained. BMFS was estimated by using the Kaplan-Meier product-limit method; factors significantly associated with BMFS in the univariate analysis were included into a Cox proportional hazard model.

Results: Median BMFS was 25 months (m; 95%CI 13.37-36.63 m). Trastuzumab-based treatment significantly prolonged median BMFS (29 vs. 11 m; p<0.01); BMFS was further improved by trastuzumab treatment in multiple lines (30 vs. 17 m; p=0.045). Co-positivity for estrogen receptor (ER) and HER2 predicted for longer BMFS (30 vs. 15 m; p<0.05). Further variables such as prior exposure to capecitabine, presence of visceral metastasis, presence of lung metastasis, stage IV disease at primary diagnosis, as well as disease free interval from adjuvant therapy were not significantly associated with BMFS. In the Cox regression model, positive ER status (HR 2.03; 95%CI 1.22-3.36; p<0.05) and trastuzumab-based treatment (HR 2.72; 95%CI 1.20-6.17; p=0.017) remained independent predictors for longer BMFS.

Conclusions: Trastuzumab-based therapy significantly prolongs BMFS in HER2-positive pts with MBC, probably due to improved systemic disease control. In line with known better survival outcome, ER/HER2 co-positive disease appears to be a less aggressive subtype of HER2-positive breast cancer associated with longer BMFS.

Abstract P4-09-02: Prognostic and Predictive Value of Centrally Reviewed Ki67 Labeling Index in Postmenopausal Women with Endocrine-Responsive Breast Cancer: Results from Austrian Breast and Colorectal Cancer Study Group Trial 8

Purpose: The aim of the present study was to assess the prognostic and predictive value of Ki67 labeling index in postmenopausal hormone receptor-positive early breast cancer patients who were treated with adjuvant tamoxifen or anastrozole after tamoxifen. Patients and Methods: We determined the expression of Ki67 by immunohistochemistry on whole tissue sections of breast carcinoma patients who had been enrolled in Austrian Breast and Colorectal Cancer Study Group (ABCSG) Trial 8 and received tamoxifen for 5 years or tamoxifen for 2 years followed by anastrozole for 3 years. Ki67 labeling index was evaluated as continuous variable or dichotomized at 10%. Distant recurrence and death were analyzed using Cox models adjusted for clinical and pathological factors.

Results: High Ki67 labeling index was observed in 394 of 1587 (23%) tumors and was associated with poor outcome. Patients with high Ki67 labeling index had a significantly shorter distant recurrence-free survival (adjusted hazard ratio [HR] for distant recurrence 2.16, 95% confidence interval [CI] 1.43-3.25, P &lt; 0.001) and overall survival (adjusted HR for death 1.77, 95% CI 1.30-2.42, P &lt; 0.001) as compared to patients with low Ki67 labeling index. No interaction between Ki67 labeling index and treatment was observed (P = 0.84).

Conclusion: High Ki67 labeling index is an independent poor prognostic factor for distant recurrence and death in postmenopausal women with early-stage, hormone receptor-positive breast cancer but is not predictive for outcome of adjuvant treatment with either tamoxifen or tamoxifen followed by anastrozole.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-09-02.

Dual inhibition of EGFR and mTOR pathways in small cell lung cancer

Background:

In this report we investigated the combination of epidermal growth factor receptor (EGFR) and mammalian target of rapamycin (mTOR) pathway inhibition as a possible new therapeutic strategy for small cell lung cancer (SCLC).

Methods:

EGFR, p-AKT, p-ERK, p-mTOR and p-p70s6K protein expressions were studied by immunohistochemistry in 107 small cell lung carcinomas and correlated with clinicopathological parameters. Cells of SCLC were treated with erlotinib±RAD001 and analysed for cell viability, proliferation, autophagy, and pathway regulation.

Results:

Epidermal growth factor receptor, p-AKT, p-ERK, p-mTOR, and p-p70s6K were expressed in 37, 24, 13, 55 and 91% of the tumour specimens of all SCLC patients, respectively, and were not associated with disease-free or overall survival. The expression of EGFR was lower in neoadjuvant-treated patients (P=0.038); mTOR pathway activation was higher in the early stages of disease (P=0.048). Coexpression of EGFR/p-mTOR/p-p70s6K was observed in 28% of all patients . EGFR immunoreactivity was associated with p-ERK and p-mTOR expression (P=0.02 and P=0.0001); p-mTOR immunoreactivity was associated with p-p70s6K expression (P=0.001). Tumour cells comprised a functional EGFR, no activating mutations in exons 18–21, and resistance to RAD001 monotherapy. We found synergistic effects of erlotinib and RAD001 combination therapy on the molecular level, cell viability, proliferation and autophagy.

Conclusions:

The combined inhibition of EGFR/mTOR pathways could be a promising approach to treat SCLC.

Rapid progression of an anal Buschke-Lowenstein tumour into a metastasising squamous cell carcinoma in an HIV-infected patient

BACKGROUND

Buschke-Löwenstein tumour (BLT) of the anogenitalia is a locally invasive, destructively growing verrucous carcinoma that does not metastasise. Histologically BLT resembles benign condylomata acuminata. Nevertheless, the tumour grows relentlessly and may rarely progress into squamous cell cancer (SCC).

RESULTS

A human immunodeficiency virus (HIV)-infected immunosuppressed patient developed (peri)anal warts accompanied by recurrent abscesses and fistulae. Histology revealed condylomata acuminata, and low-risk genital human papillomavirus (HPV) type 11b was detected. Six months later, the tumour had progressed into an ulcerated SCC that destroyed the rectum and perineum, with metastases to the inguinal lymph nodes. Whereas highly active antiretroviral therapy (HAART) effectively suppressed HIV replication, radiochemotherapy plus anti-EGFR antibody did not halt tumour progression, and the patient died from tumour-cachexia.

DISCUSSION

As far as is known, this is the first report demonstrating rapid progression of a BLT into a metastasising SCC in an HIV-infected patient.