G. Floris

The evaluation of tumor-infiltrating lymphocytes (TILs) in breast cancer: recommendations by an International TILs Working Group 2014

BACKGROUND The morphological evaluation of tumor-infiltrating lymphocytes (TILs) in breast cancer (BC) is gaining momentum as evidence strengthens for the clinical relevance of this immunological biomarker. Accumulating evidence suggests that the extent of lymphocytic infiltration in tumor tissue can be assessed as a major parameter by evaluation of hematoxylin and eosin (H&E)-stained tumor sections. TILs have been shown to provide prognostic and potentially predictive value, particularly in triple-negative and human epidermal growth factor receptor 2-overexpressing BC. DESIGN A standardized methodology for evaluating TILs is now needed as a prerequisite for integrating this parameter in standard histopathological practice, in a research setting as well as in clinical trials. This article reviews current data on the clinical validity and utility of TILs in BC in an effort to foster better knowledge and insight in this rapidly evolving field, and to develop a standardized methodology for visual assessment on H&E sections, acknowledging the future potential of molecular/multiplexed approaches. CONCLUSIONS The methodology provided is sufficiently detailed to offer a uniformly applied, pragmatic starting point and improve consistency and reproducibility in the measurement of TILs for future studies.

A critical review why assessment of steroid hormone receptors in breast cancer should be quantitative

Steroid receptors have been around in the field of breast cancer for decades now. Still, controversy remains on how best to report steroid receptors. In this review, we will convince the reader why benefits outweigh pitfalls, when reporting steroid receptors in a quantitative rather than qualitative way. Summarizing decades of research in this field, we will explore the evidence why quantitative reporting is superior in all settings (neoadjuvant, adjuvant and metastatic settings). Furthermore, we will also summarize different staining methods, definitions and pitfalls that have shown to be important points of discussion in earlier debates. Although the molecular unraveling of breast cancer in the past decade has revolutionized the way we think about breast cancer, we should not easily abandon the classical pathological variables such as steroid receptors in favor of molecular tools.

Breast cancer phenotype, nodal status and palpability may be useful in the detection of overdiagnosed screening-detected breast cancers

BACKGROUND Breast cancer remains the leading cause of female cancer death despite improvements in treatment and screening. Screening is often criticized for leading to overdiagnosis and overtreatment. However, few have attempted to identify overdiagnosed cases. PATIENTS AND METHODS A large, consecutive series of patients treated for primary operable, screening-detected, breast cancer (n = 1610). Details from pathology and clinical reports, treatment and follow-up were available from our prospectively managed database. Univariate and multivariate Cox proportional models were used to study the prognostic variables in screening-detected breast cancers for distant metastatic and breast cancer-specific survival. RESULTS We included 1610 patients. The mean/median follow-up was 6.0/6.0 years. Univariate analysis: tumor size, palpability, breast cancer phenotype and nodal status were predictors of distant metastasis and breast cancer-specific death. Multivariate analysis: palpability, breast cancer phenotype and nodal status remained independent prognostic variables. Palpability differed by breast cancer phenotype. CONCLUSION Screening-detected breast cancer is associated with excellent outcome. Palpability, nodal status and breast cancer phenotype are independent prognostic variables that may select patients at increased risk for distant metastatic relapse and breast cancer-specific death. Overdiagnosed cases reside most likely in the nonpalpable node negative subgroup with a Luminal A phenotype.BACKGROUND Breast cancer remains the leading cause of female cancer death despite improvements in treatment and screening. Screening is often criticized for leading to overdiagnosis and overtreatment. However, few have attempted to identify overdiagnosed cases. PATIENTS AND METHODS A large, consecutive series of patients treated for primary operable, screening-detected, breast cancer (n = 1610). Details from pathology and clinical reports, treatment and follow-up were available from our prospectively managed database. Univariate and multivariate Cox proportional models were used to study the prognostic variables in screening-detected breast cancers for distant metastatic and breast cancer-specific survival. RESULTS We included 1610 patients. The mean/median follow-up was 6.0/6.0 years. Univariate analysis: tumor size, palpability, breast cancer phenotype and nodal status were predictors of distant metastasis and breast cancer-specific death. Multivariate analysis: palpability, breast cancer phenotype and nodal status remained independent prognostic variables. Palpability differed by breast cancer phenotype. CONCLUSION Screening-detected breast cancer is associated with excellent outcome. Palpability, nodal status and breast cancer phenotype are independent prognostic variables that may select patients at increased risk for distant metastatic relapse and breast cancer-specific death. Overdiagnosed cases reside most likely in the nonpalpable node negative subgroup with a Luminal A phenotype.

Prognostic implications of lobular breast cancer histology: new insights from a single hospital cross-sectional study and SEER data.

BACKGROUND Invasive lobular breast cancer (ILC) is generally believed to have an increased risk for late relapse compared to invasive ductal breast cancer (IDC). However, the study most often referred to is a chemotherapy trial that mainly included node positive patients. We hypothesize that nodal status may influence the hazard of relapse since time of diagnosis differently in invasive ductal carcinoma (IDC) and ILC. METHODS Primary operable breast cancer patients from our institution diagnosed between 2000 and 2009 were studied. Multivariable analysis and subgroup analyses were performed to assess whether ILC carries a different prognosis compared to IDC. SEER data were used for external validation. RESULTS In lymph node negative patients, ILC carries a better prognosis regarding distant metastasis free interval (DMFI) (HR 3.242 (1.380-7.614), p = 0.0069) with a trend towards improved breast cancer specific survival (BCSS), over the entire study frame (UZ Leuven data). In lymph node positive patients, both DMFI (HR 0.466 (0.309-0.703), p = 0.0003) and BCSS (HR 0.441 (0.247-0.788), p = 0.0057) are significantly worse for ILC, especially after longer follow-up (>4-5 years) (UZ Leuven data). Similar results were found in the SEER cohort. Results remained identical when excluding screen detected cases (data not shown). CONCLUSION The prognostic impact of lobular histology not only depends on time since diagnosis but also on nodal status. The general believe that ILC have compromised late-term outcome compared to IDC seems untrue for the majority ( = node negative) of ILCs.

Withdrawal of hormone replacement therapy might affect multigene signature results in early luminal breast cancer

ABSTRACT In this case-report we established a discordance of luminal subtype between core needle biopsy results at breast cancer diagnosis and surgical specimen results after hormone replacement therapy withdrawal at diagnosis. This observation might suggest that short term change in hormonal environment prior to breast cancer surgery might affect multi-gene signature results.

Stromal inflammation, necrosis and HER2 overexpression in ductal carcinoma in situ of the breast: another causality dilemma?

Institution/affiliations 1. Department of Pathology, Ghent University Hospital, Ghent, Belgium. 2. Department of Medical and Forensic Pathology & Cancer Research Institute Ghent (CRIG), Ghent University, Ghent, Belgium. 3. Department of Pathology, University Clinics Saint Luc, Brussels, Belgium. 4. Department of Imaging and Pathology, Laboratory of Translational Cell & Tissue Research, University of Leuven, Leuven, Belgium. 5. Department of Pathology, University Hospitals Leuven, Leuven, Belgium. 6. Department of Pathology, AZ St Lucas Hospital, Ghent, Belgium. 7. Department of Oncology, KU Leuven, Surgical Oncology, University Hospitals Leuven, Leuven, Belgium. 8. Breast Research Pathology, Division of Cancer Studies, King’s College London, Guy’s Hospital, London, UK. (*E-mail: Mieke.VanBockstal@UGent.be)

Abstract P2-03-05: Identification, clinical characteristics and treatment outcomes of somatic human epidermal growth factor receptor 2 (ERBB2) mutations in metastatic breast cancer patients

Background Metastatic breast cancer (MBC) is seen as incurable and advances in new therapies or targets are necessary. Targeted therapies against human epidermal growth factor receptor 2 (ERBB2) (also known as HER2) in tumors with ERBB2 overexpression due to gene amplification have improved patients outcomes. Besides ERBB2 amplification, this receptor can also be altered by somatic mutations (without ERRB2 amplification) that likely drive tumorigenesis. Neratinib, an irreversible pan-HER tyrosine kinase inhibitor, has recently been demonstrated to potently inhibit breast cancers that have amplification or activating mutations in ERBB2. This is the first study that thoroughly investigates the natural history of ERBB2 mutations in MBC patients. The primary study objectives are to 1) evaluate the frequency of ERBB2 mutations in a large MBC cohort, 2) understand standard clinical, pathological and patient characteristics associated with ERBB2 mutations, 3) identify other gene mutations/aberrations that may co-occur with ERRB2 mutations, 4) characterize treatment responses and outcomes to standard therapies in patients with ERBB2 mutant vs. wild-type tumors, and 5) determine if ERBB2 mutations can be detected from plasma ctDNA samples collected at baseline (not reported here). Patients and Methods This retrospective study included all MBC patients (primary metastatic or developed metastases during follow-up), independent of hormone receptor or HER2 amplification status, diagnosed between January 1st 2000 and July 31st 2015 at the Multidisciplinary Breast Center of University Hospitals Leuven, and for whom sufficient tumor material was available for DNA extraction. Extracted DNA from primary breast cancer tissues were subject to targeted NGS-based sequencing, to identify single nucleotide variants, insertion, deletion, and indels within exons 8, 17, 19, 20 and 21 of the ERBB2 gene. Results We established and validated a research use only next-generation sequencing assay across five exons of the ERBB2 gene. 1062 MBC patients were included and so far 177 patients were successfully screened for ERBB2 mutations resulting in an occurrence of n=10 (5.6%) in this population. The remaining patients are currently being screened for ERBB2 mutations and the overall results on all described endpoints will be available at the meeting. Conclusion ERBB2 mutations seem more frequent in MBC than previously thought based on the general early breast cancer population. In depth analysis of this large MBC cohort evaluating clinical characteristics and standard treatment outcomes of ERBB2 mutant MBC may provide further knowledge on this breast cancer subtype that may benefit from HER2-directed therapies which are currently under investigation in clinical trials. Citation Format: Jongen L, Floris G, Lambrechts D, Laenen A, Neven P, Cutler Jr. RE, Lalani AS, Wildiers H. Identification, clinical characteristics and treatment outcomes of somatic human epidermal growth factor receptor 2 (ERBB2) mutations in metastatic breast cancer patients [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 P2-03-05.

Abstract P6-09-12: Breast cancer characteristics and the levonorgestrel intrauterine device. A monocentric retrospective study

OBJECTIVE: The levonorgestrel-intrauterine device (LNG-IUD) is a widely used contraceptive method. It is not clear if LNG-IUD users are more likely to develop breast cancer. Breast cancer growth through the estrogen and/or the human epidermal growth factor receptor 2 (HER2) pathway could be influenced by a continuous low systemic dose of levonorgestrel. In this study, we compare breast cancer characteristics and the receptor expression of estrogen (ER), progesterone (PR) and HER2 in women with and without a LNG- IUD at the time of diagnosis. METHODS: In this retrospective, observational study, we included 2599 consecutive breast cancer patients who were younger than 55 years at diagnosis and treated between 2000 and 2014 in the University Hospitals Leuven for a primary invasive, non-metastatic tumor. The non LNG-IUD group was matched by age and parity at diagnosis. ER, PR and HER2 status were reported according to ASCO/CAP guidelines. The Chi-square test was used to compare receptor status between groups. All tests were two-sided, and a 5% significance level was assumed. An additional analysis was performed to detect the occurrence of HER 2 expression with or without intake of oral contraception by diagnosis in the control group. RESULTS: 366 LNG-IUD users and 2233 women without a LNG-IUD were included. Compared to the control group, the LNG-IUD users had a lower Nottingham prognostic index (4.2 vs 4.4; p=0.048), more PR expression (79.2% vs 73.4%; p=0.021) but less HER2 expression (11.6% vs 17.2%; p=0.009). A significant higher rate of ER+PR+HER2- was observed in the LNG-IUD group (63.26 % vs 73.46%; p CONCLUSION: We found in a breast cancer population, matched for age and parity, significant differences in the PR and HER2 expression according to use of LNG-IUD at time of diagnosis. ER positive, PR positive and HER2 negative breast cancers are more frequently seen in LNG-IUD users. There is a trend of less HER 2 positivity in LNG-IUD users and it is more common seen in oral contraception users. Citation Format: Borowski E, Poppe A, Laenen A, Remmerie C, Van Asten K, Nevelsteen I, Smeets A, Weltens C, Peeters S, Leunen K, Berteloot P, Amant F, Vergote I, Van Limbergen E, Christiaens M-R, Wildiers H, Floris G, Poppe W, Neven P. Breast cancer characteristics and the levonorgestrel intrauterine device. A monocentric retrospective study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-09-12.

Abstract P6-10-06: The impact of body mass index on age at breast cancer diagnosis and breast cancer phenotype

Background Evidence suggests that premenopausal obesity decreases and postmenopausal obesity increases breast cancer risk. While it has been hypothesized that carcinogenesis may be accelerated by a disrupted metabolic homeostasis in obese women, it is unclear why this dual relationship is observed. We here study whether body mass index (BMI) affects (a) age at breast cancer diagnosis and (b) the probability of being diagnosed with a specific breast cancer phenotype, taking menopausal status into account. Patients and methods All patients with non-metastatic operable breast cancer from UZ Leuven diagnosed between January 1, 2000 and December 31, 2013 were included (n=7020). Luminal A like (= grade 1 or 2, ER and/or PR positive, HER2 negative), Luminal B like (= grade 3 ER and/or PR positive, HER2 negative), Luminal HER2 like (ER and/or PR positive, HER2 positive), HER2 like (ER and PR negative, HER2 positive) and triple negative breast cancer (TNBC = ER and PR and HER2 negative). For statistical analysis, linear models and logistic regression were used to study respectively the association between BMI and age at diagnosis and BMI and breast cancer phenotype by menopausal status. Results There was a quadratic relationship between BMI and age at breast cancer diagnosis studying the overall population (p We observed a linear relationship between BMI and the probability of being diagnosed with Luminal B like, Luminal HER2 like and HER2 like breast cancer (table 1). This linear relationship interacts with menopausal status for Luminal B like and HER2 like breast cancers (table 1). Conclusion We could not confirm the hypothesis that increasing BMI decreases (increases) age at diagnosis in postmenopausal (premenopausal) women. Obesity does affect the probability of being diagnosed with certain breast cancer phenotypes, but for certain breast cancer phenotypes an interaction with menopause was observed. We presume a potential biological link through BMI between Luminal B and HER2 like breast cancer that needs further exploration. Citation Format: Brouckaert O, Poppe A, Laenen A, Floris G, Leunen K, Berteloot P, Amant F, Vergote I, Smeets A, Weltens C, Peeters S, Van Limbergen E, Wildiers H, Christiaens M-R, Neven P. The impact of body mass index on age at breast cancer diagnosis and breast cancer phenotype. [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 P6-10-06.

Abstract P5-08-31: Withdrawal of exogenous hormones affects prognostic multigene signature results in early luminal breast cancer

Background Early breast cancer (BC) outcomes are mainly estimated based on clinicopathological parameters and rarely include proliferation markers: (Ki-67), and multigene signatures (MGS), which are typically measured in tumors from resection specimens (RS). We believe that tumor proliferation can change within days of anti-estrogen use. However, little is known how proliferation changes after withdrawal of hormone replacement therapy (HRT) or oral anti-conception (OAC) after a core needle biopsy (CNB) shows BC. Hence, this study compares the Ki-67 labeling index and the MGS results in CNB and RS collected from a cohort of patients under OAC/HRT. Patients and Methods This retrospective study included consecutive women diagnosed with a grade 1-2, any pTN0-1, primary operable estrogen receptor-positive, human epidermal growth factor receptor 2-negative, and invasive ductal carcinoma between January 2013 and July 2014 at the Multidisciplinary Breast Center of University Hospitals Leuven were selected from a prospectively managed database. Ki-67 staining was performed on RS (Ki-67 RS ) to compare those who used HRT/OAC for at least 3 months at diagnosis and those not using OAC/HRT at diagnosis. OAC/HRT was always stopped between CNB and RS. Subsequently, we compared Ki-67 of the CNB (Ki-67 CNB ) with the matched RS in 15 patients with a low Ki-67 RS (14%) stopping OAC/HRT after CNB; revised standard pathology confirmed absence of tumor heterogeneity in all samples. In addition, in a subset of patients (≥50 years, Ki-67 RS ≤5%) we compared Ki-67 index and MGS results (MammaPrint (MP) and BluePrint, Agendia) from the CNB versus RS. Results 193 patients with a known Ki-67 RS were included; 38 patients (mean age of 55 years) were on OAC/HRT at CNB and 155 patients (mean age of 64 years) were not. The median time between stopping OAC/HRT and resection was 23 days (range 8-48 days). Ki-67 RS was RS (≤14%) and had a high matched Ki-67CNB (≥15%). In another subset of four out of 15 patients we compared CNB and RS (table1) where we observed changes in both Ki-67 and MGS. Conclusion Women on OAC/HRT, at diagnosis of an early luminal BC, are more likely to have a lower Ki-67 RS as those not using OAC/HRT. Our findings are likely explained by a sudden decrease in sex steroids after BC diagnosis, resulting in lower proliferation markers. As such, a lower hormonal environment by withdrawing HRT/OAC at BC diagnosis might underestimate proliferation markers used for prognostic and predictive purposes. Therefore we are currently testing this hypothesis in larger cohorts. Citation Format: Jongen L, De Vries P, Van Asten K, Lintermans A, Laenen A, Wildiers H, Floris G, Neven P. Withdrawal of exogenous hormones affects prognostic multigene signature results in early luminal breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-31.