Eva Balslev

Triple-negative breast cancer (TNBC) is an aggressive and difficult-to-treat cancer type that represents approximately 15% of all breast cancers. Recently, stromal tumor-infiltrating lymphocytes (sTIL) resurfaced as a strong prognostic biomarker for overall survival (OS) for TNBC patients. Manual assessment has innate limitations that hinder clinical adoption, and the International Immuno-Oncology Biomarker Working Group (TIL-WG) has therefore envisioned that computational assessment of sTIL could overcome these limitations and recommended that any algorithm should follow the manual guidelines where appropriate. However, no existing studies capture all the concepts of the guideline or have shown the same prognostic evidence as manual assessment. In this study, we present a fully automated digital image analysis pipeline and demonstrate that our hematoxylin and eosin (H&E)-based pipeline can provide a quantitative and interpretable score that correlates with the manual pathologist-derived sTIL status, and importantly, can stratify a retrospective cohort into two significant distinct prognostic groups. We found our score to be prognostic for OS (HR: 0.81 CI: 0.72–0.92 p = 0.001) independent of age, tumor size, nodal status, and tumor type in statistical modeling. While prior studies have followed fragments of the TIL-WG guideline, our approach is the first to follow all complex aspects, where appropriate, supporting the TIL-WG vision of computational assessment of sTIL in the future clinical setting.

Fulvestrant is a selective oestrogen receptor (ER) degrader used as monotherapy and combination therapy for ER positive HER2 negative advanced breast cancer (ABC) in postmenopausal women. The drug response predictor (DRP), is a mathematical algorithm based on the expression of multiple genes in the tumour. The fulvestrant DRP algorithm has previously shown effect in BC. In this study, we investigated the DRP’s potential in predicting fulvestrant benefit.

Treatment options in metastatic breast cancer are limited. New therapies preferable with predictive biomarkers are needed. The aim of these trials was to investigate if gene copy number of the topoisomerase 1 gene was predictive of response to the topoisomerase inhibitor irinotecan. Two open-label, single-arm phase II studies including HER2 positive and negative patients were conducted. Patients were eligible for inclusion if the primary tumor or a metastatic lesion had increased expression of the topoisomerase 1 gene defined as a TOP1 gene copy number of ≥4 or a TOP1/CEN20 ratio of ≥2. Patients were treated with irinotecan +/− trastuzumab weekly for 4 weeks following 2 weeks break, until progression or unacceptable toxicities. Evaluation scans were performed every 6 weeks. Primary endpoint was clinical benefit rate defined as the fraction of patients with stable disease for ≥4 months. The pre-planned number of 18 patients in each trial was not reached, thus no formal statistical analysis could be performed. Nine patients with HER2 negative disease and three patients with HER2 positive disease were included. Three patients obtained a partial remission and two patients had SD. The trials did not include the planned number of patients. No association between gene copy number of the topoisomerase 1 gene and response to irinotecan could be proved, however a clinical benefit was found in 5/12 patients and in 2/3 patients with HER2 positive disease. This could call for further investigation of the drug in the metastatic setting, especially in HER2 positive BC. Eudract registration numbers 2012–002348-26 and 2012–002347-23 . Registration date August 20th 2012.

E12532 Background: Exemestaneis a steroidal aromatase inhibitor used in the treatment of postmenopausal patients with estrogen receptor(ER)-positive adjuvant and advanced breast cancer. We aimed to determine the predictive value of a multigene mRNA-based mathematical algorithm (Drug Response Predictor (DRP)) for benefit of exemestane. The DRP is founded on measuring the full cancer transcriptome in sensitive and drug resistant cell lines compared with expression patterns in tumors and broadly validated in several studies (Wang et al. JNCI (2013) 105 (17): 1284-1291.) (Knudsen, S. et al. PLoS One (2014) 9(2): e87415.) (Christensen, TD et al. J Clin Oncol (2016) 34: suppl; abstr e12056.) (Kappel, IB et al. J Clin Oncol (2016) 34: suppl; abstr e20007.). Methods: Among 838 consecutive patients from a DBCG cohort with advanced breast cancer treated at 10 participating sites we identified 163 patients who between November 2008 and November 2015 initiated exemestane. All but one patient were ER-positive. Patients were evaluated every 3 to 4 months using CT scans and clinical examination. After patient informed consent mRNA was extracted and assayed on Affymetrix Gene Chip U133p2 arrays from formalin fixed paraffin embedded diagnostic biopsies. The primary endpoint was progression free survival (PFS). Analysis of the DRP’s ability to predict PFS was performed using a Cox regression model adjusted for treatment line. Results: Median PFS was 8.5 months. Of the 163 patients, 101 received prior adjuvant antihormone therapy and 60 did not. Data regarding adjuvant therapy was inaccessible for two patients. Hazard ratios for patients with predicted good vs. poor effect of exemestane are shown in the table. Conclusions: In a clinical setting, a mathematical algorithm using mRNA from a diagnostic biopsy can in patients unexposed to previous adjuvant endocrine therapy with statistical significance predict who will benefit from exemestane. [Table: see text]

1071 Background: Epirubicin remains a cornerstone in the treatment of primary and advanced breast cancer. This study evaluated the predictive effect of a multigene mRNA-based Drug Response Predictor (DRP) in the treatment of advanced breast cancer (ABC). We applied a mathematical method combining in vitro sensitivity with gene expression patterns in tumors. Previously the DRP has been broadly validated^{1, 2} including retrospective validation of epirubicin³. Methods: Among 838 consecutive patients from a DBCG cohort 137 patients were treated with epirubicin between May 1997 and November 2016 at one of the participating sites. Patients were examined every 9 to 12 weeks by CT scan and clinical evaluation. After patient informed consent, mRNA was isolated from formalin fixed paraffin embedded tumor tissue from diagnostic biopsies and analyzed using Affymetrix arrays. Blinded predictions of epirubicin efficacy were compared to clinical data collected retrospectively from patients’ medical records. Statistical analysis was done using Cox proportional hazards model adjusted for treatment line. Primary endpoint was progression free survival (PFS). Results: Median time to progression was 9.3 months (95% CI: 7.2-13.2). Of the 137 patients, four received epirubicin more than once. Scoring the DRP as a continuous covariate demonstrated that the DRP was significantly associated to PFS (p = 0.02). The estimated hazard ratio was 0.56 (90% CI: 0.35-0.89) comparing two patients with DRP score differing by 50 percentage points. The estimated median time to progression for a patient with a DRP value of 25% was 7 months versus 13 months for a patient with a DRP value of 75%. No interaction with previous adjuvant chemotherapy was observed (p = 0.98). Conclusions: The current study demonstrates a potential clinical value by being able to select patients that benefit from epirubicin against patients predicted not to benefit sparing the last patients unnecessary toxicity. Studies evaluating the predictor in an adjuvant setting will follow. ¹ Knudsen et al PLoS ONE 9(2): e87415; ² Buhl et al PLoS ONE 11(5): e0155123; ³ Wang et al JNCI 105(17): 1284-91

About 20% of patients with primary breast cancer develop metastatic disease during the course of the disease. At this point the disease is considered incurable and thus treatment is aimed at palliation and life prolongation. As many patients will have received both an anthracycline and a taxane in the adjuvant setting, treatment options for metastatic breast cancer are limited. Furthermore response rates for the most commonly used drugs range from around 30% to 12% . Thus new treatment options are needed and preferably coupled to biomarkers predictive of response. Irinotecan is a topoisomerase 1 inhibitor used for decades for the treatment of colorectal cancer. Four studies have investigated the efficacy of irinotecan monotherapy in breast cancer and all have included non-biomarker selected patients. In these studies response rates for irinotecan ranged from 5%-23% and are thus comparable to response rates obtained with drugs commonly used in the metastatic setting. If a predictive biomarker could be identified for irinotecan, response rates might be even higher. This multi-centre phase II single arm trial was designed to investigate if patients with metastatic breast cancer and increased expression of the topoisomerase 1 gene have a high likelihood of obtaining a clinical benefit from treatment with irinotecan. Trial recruitment is two-staged as 19 patients are planned to participate in the first part. If less than 7 patients have clinical benefit the trial stops, if more than 7 patients have clinical benefit a total of 40 patients will be included. This ongoing trial is the first to prospectively test copy number of the topoisomerase I gene as a predictive biomarker of response to irinotecan. EudraCT number 2012-002348-26 .

Tissue inhibitor of metalloproteinases-1 (TIMP-1) has anti-apoptotic functions, which may protect TIMP-1 positive cancer cells from the effects of chemotherapy such as docetaxel and gemcitabine. The purpose of the present study was to evaluate TIMP-1 immunoreactivity as a prognostic and predictive marker in advanced breast cancer patients receiving docetaxel (D) or gemcitabine plus docetaxel (GD).