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Kok, Marleen

https://orcid.org/0000-0001-9043-9815

Mayo Clinic

The Netherlands Cancer Institute

Citations 5

Enhancing Clinical Cancer Research Through Sharing of Data and Biospecimens
Wildiers, Hans, O’Reilly, Séamus , Cauwenberge, Josephine Van , Arahmani, Amal, Arteaga, Carlos L. , Bédard, Philippe L. , Bliss, Judith M. , Boussis, Panayota, Caballero, Carmela, Cameron, David , Carrasco, Eva , Casas, Ana, Chua, Boon , DeMichele, Angela, Esserman, Laura, Hodgdon, Christine, Ignatiadis, Michail, Kok, Marleen , Lacombe, Denis, Linderholm, Barbro, Loi, Sherene, MacKenzie, Mairead, Maués, Julia , Meheus, Lydie , Neven, Patrick, Parsons, Heather A. , Piccart, Martine , Pusztai, Lajos, Razis, E. , Schumacher-Wulf, Eva, Spanic, Tania, Tutt, Andrew , Veer, Laura van ‘t , Werutsky, Gustavo, Yee, Douglas , Zaman, Khalil , Desmedt, Christine , Bliss, Judith , Yee, Douglas , Adam, Virginie Sarah , Brain, Etienne G.C. , Buyse, Marc , Cameron, David, Cardoso, Fátima , Curigliano, Giuseppe , Floris, Giuseppe , Goetz, Matthew P. , Goulioti, Theodora , Haibe‐Kains, Benjamin , Hodgdon, Christine, Linderholm, Barbro Kristina , Lord, Christopher J. , MacKenzie, Mairead, Needham, Judy , Neven, Patrick , Pusztai, Lajos , Saji, Shigehira , Sonke, Gabe S. , Spanic, Tania, Tannock, Ian F. , Urruticoechea, Ander , Veer, Laura J. van’t , Vaz-Luís, Inês , Werutsky, Gustavo

JAMA Oncology | December 18, 2025 | Volume: 12 | Issue: 2 | Pages: 200

10.1001/jamaoncol.2025.5376 Get It

Importance Molecular analyses of biospecimens collected from study participants are essential for identifying biomarkers that can tailor treatments to specific subsets of patients who are most likely to benefit. Sharing of data and biospecimens from clinical trials enables personalized, patient-centric use of cancer therapies and accelerates the development of new treatments. Objective To describe obstacles to sharing data and biospecimens and to propose strategies to enhance access and collaboration. Evidence Review This is a Special Communication authored by 53 academic investigators and patient representatives from the breast cancer community with extensive experience in conducting clinical and translational research. The article also evaluates the impact of biomarker research on specifying responsive subpopulations in the 29 registrational clinical trials that have led to approval of a new drug for treatment of breast cancer between 2017 and 2024. Findings Clinical trial participants are increasingly asked to provide tissue and/or body fluid biospecimens for biomarker research that is typically controlled by the sponsoring pharmaceutical company, but published biomarker studies are rare. Among 29 breast cancer registrational studies reported in the past 8 years, none resulted in biomarker research that restricted a drug’s approved indication. Herein, strategies to maximize the value of clinical data and biospecimens contributed by participants are proposed, thereby supporting the shared goals of the pharmaceutical industry and academia to improve patient care. These strategies include (1) establishing coleadership structures involving academia and patients in clinical trial design and conduct, (2) ensuring that informed consent forms state that data and biospecimens will be shared with academia for future research, (3) requiring the sharing of clinical data as a condition for regulatory approval, and (4) enabling access to biospecimens and translational research data for independent studies on biomarkers that may indicate drug efficacy and toxicity. Conclusions and Relevance Data and biospecimen sharing from registrational trials has been suboptimal. Improving clinical data, biospecimens, and biospecimens’ related data sharing requires concrete actions and a multidimensional stakeholder approach to accelerate the impact of clinical cancer research on the quality of patient care.
Tumor-Infiltrating Lymphocytes in Patients With Stage I Triple-Negative Breast Cancer Untreated With Chemotherapy
Geurts, Veerle , Steenbruggen, Tessa G. , Siesling, Sabine , Leon‐Ferre, Roberto A. , Klar, Natalie , Salgado, Roberto , Kok, Marleen , Klar, Natalie J , Balduzzi, Sara , Linn, Sabine C. , Badve, Sunil , DeMichele, Angela , Ignatiadis, Michail , Goetz, Matthew P. , Wolff, Antonio C. , Michiels, Stefan , Loi, Sherene , Adams, Sylvia , Horlings, Hugo , Sonke, Gabe S.

JAMA Oncology | June 27, 2024 | Volume: 10 | Issue: 8 | Pages: 1077

10.1001/jamaoncol.2024.1917 Get It

ImportanceThe absolute benefit of chemotherapy for all patients with stage I triple-negative breast cancer (TNBC) is unclear, and biomarkers are not currently available for selecting patients with an excellent outcome for whom neoadjuvant or adjuvant chemotherapy may have negligible benefit. High levels of stromal tumor-infiltrating lymphocytes (sTILs) are associated with favorable survival in TNBC, but data solely in stage I TNBC are lacking.ObjectiveTo examine the outcomes of patients of all ages with stage I TNBC solely and who received neither neoadjuvant nor adjuvant chemotherapy, according to centrally reviewed sTIL levels at prespecified cutoffs.Design, Setting, and ParticipantsThis cohort study used the Netherlands Cancer Registry to identify patients diagnosed with stage I TNBC between January 1, 2005, and December 31, 2015, who were not treated with chemotherapy. Only patients who did not receive neoadjuvant and/or adjuvant chemotherapy were selected. The clinical data were matched with their corresponding pathology data provided by the Dutch Pathology Registry. Data analysis was performed between February and October 2023.Main Outcomes and MeasuresThe primary end point was breast cancer–specific survival (BCSS) at 5, 10, and 15 years for the prespecified sTIL level cutoffs of 30%, 50%, and 75%. Hematoxylin and eosin–stained slides were used for central review of histologic subtype, grade, and lymphovascular invasion. The International Immuno-Oncology Biomarker Working Group guidelines were used to score the sTIL levels; these levels were determined for 1041 patients.ResultsOf a total of 4511 females with stage I TNBC, patients who were not treated with chemotherapy were selected and tissue blocks requested; sTILs were scored in 1041 patients (mean [SD] age at diagnosis, 64.4 [11.1] years, median follow-up 11.4 [95% CI, 10.9-11.9] years) who were included in the analyses.. Most tumors (952 [91.5%]) were invasive carcinomas of nonspecial histologic subtype. Most patients (548 [52.6%]) had pT1cN0 tumors. Median (range) sTIL level was 5% (1%-99%). A total of 775 patients (74.4%) had sTIL levels below 30%, 266 (25.6%) had 30% or greater, 203 (19.5%) had 50% or greater, and 141 (13.5%) had 75% or greater. Patients with pT1abN0 tumors had a more favorable outcome vs patients with pT1cN0 tumors, with a 10-year BCSS of 92% (95% CI, 89%-94%) vs 86% (95% CI, 82%-89%). In the overall cohort, sTIL levels of at least 30% were associated with better BCSS compared with sTIL levels less than 30% (96% and 87%, respectively; hazard ratio [HR], 0.45; 95% CI, 0.26-0.77). High sTIL levels of 50% or greater were associated with a better outcome than low sTIL levels of less than 50% (HR, 0.27; 95% CI, 0.10-0.74) in patients with pT1C tumors, with a 10-year BCSS of 95% increasing to 98% with sTIL levels of 75% or greater.Conclusions and RelevanceResults of this study showed that patients with stage I TNBC and high level of sTILs who did not receive neoadjuvant or adjuvant chemotherapy had excellent 10-year BCSS. The findings further support the role of sTILs as integral biomarkers in prospective clinical trials of therapy optimization for this patient population.
Tumor-Infiltrating Lymphocytes in Triple-Negative Breast Cancer
Leon‐Ferre, Roberto A. , Jonas, Sarah Flora , Salgado, Roberto, Loi, Sherene , Jong, Vincent de, Carter, Jodi M. , Leung, Samuel , Riaz, Nazia , Chia, Stephen , Jules-Clément, Gérôme , Curigliano, Giuseppe , Linderholm, Barbro, Deurzen, Carolien H. M. van , Timmermans, Anne, Yazaki, Shu, Yoshida, Masayuki , Bataillon, Guillaume , Kok, Marleen , Group, International Immuno-Oncology Biomarker Working, Curigliano, Giuseppe , Loi, Sherene , Carter, Jodi , Salgado, Roberto , Nielsen, Torsten O. , Criscitiello, Carmen , Cockenpot, Vincent , Lambertini, Matteo , Suman, Vera J. , Linderholm, Barbro Kristina , Martens, John W.M. , Timmermans, A. Mieke, Shimoi, Tatsunori , Kim, Sung-Bae , Lee, Hee Jin , Dieci, Maria Vittoria , Vincent‐Salomon, Anne , André, Fabrice , Linn, Sabine C. , Goetz, Matthew P. , Michiels, Stefan , Group, International Immuno-Oncology Biomarker Working

JAMA | April 2, 2024 | Volume: 331 | Issue: 13 | Pages: 1135

10.1001/jama.2024.3056 Get It

Importance The association of tumor-infiltrating lymphocyte (TIL) abundance in breast cancer tissue with cancer recurrence and death in patients with early-stage triple-negative breast cancer (TNBC) who are not treated with adjuvant or neoadjuvant chemotherapy is unclear. Objective To study the association of TIL abundance in breast cancer tissue with survival among patients with early-stage TNBC who were treated with locoregional therapy but no chemotherapy. Design, Setting, and Participants Retrospective pooled analysis of individual patient-level data from 13 participating centers in North America (Rochester, Minnesota; Vancouver, British Columbia, Canada), Europe (Paris, Lyon, and Villejuif, France; Amsterdam and Rotterdam, the Netherlands; Milan, Padova, and Genova, Italy; Gothenburg, Sweden), and Asia (Tokyo, Japan; Seoul, Korea), including 1966 participants diagnosed with TNBC between 1979 and 2017 (with follow-up until September 27, 2021) who received treatment with surgery with or without radiotherapy but no adjuvant or neoadjuvant chemotherapy. Exposure TIL abundance in breast tissue from resected primary tumors. Main Outcomes and Measures The primary outcome was invasive disease-free survival [iDFS]. Secondary outcomes were recurrence-free survival [RFS], survival free of distant recurrence [distant RFS, DRFS], and overall survival. Associations were assessed using a multivariable Cox model stratified by participating center. Results This study included 1966 patients with TNBC (median age, 56 years [IQR, 39-71]; 55% had stage I TNBC). The median TIL level was 15% (IQR, 5%-40%). Four-hundred seventeen (21%) had a TIL level of 50% or more (median age, 41 years [IQR, 36-63]), and 1300 (66%) had a TIL level of less than 30% (median age, 59 years [IQR, 41-72]). Five-year DRFS for stage I TNBC was 94% (95% CI, 91%-96%) for patients with a TIL level of 50% or more, compared with 78% (95% CI, 75%-80%) for those with a TIL level of less than 30%; 5-year overall survival was 95% (95% CI, 92%-97%) for patients with a TIL level of 50% or more, compared with 82% (95% CI, 79%-84%) for those with a TIL level of less than 30%. At a median follow-up of 18 years, and after adjusting for age, tumor size, nodal status, histological grade, and receipt of radiotherapy, each 10% higher TIL increment was associated independently with improved iDFS (hazard ratio [HR], 0.92 [0.89-0.94]), RFS (HR, 0.90 [0.87-0.92]), DRFS (HR, 0.87 [0.84-0.90]), and overall survival (0.88 [0.85-0.91]) (likelihood ratio test, P < 10e-6). Conclusions and Relevance In patients with early-stage TNBC who did not undergo adjuvant or neoadjuvant chemotherapy, breast cancer tissue with a higher abundance of TIL levels was associated with significantly better survival. These results suggest that breast tissue TIL abundance is a prognostic factor for patients with early-stage TNBC.
Abstract PD9-05: Stromal tumor-infiltrating lymphocytes identify early-stage triple-negative breast cancer patients with favorable outcomes at 10-year follow-up in the absence of systemic therapy: a pooled analysis of 1835 patients
Leon‐Ferre, Roberto A. , Jonas, Sarah Flora , Salgado, Roberto, Jong, Vincent de, Nielson, Torsten, Leung, Samuel , Riaz, Nazia , Linderholm, Barbro, Deurzen, Carolien HM van, Timmermans, Mieke, Yazaki, Shu, Yoshida, Masayuki , Kok, Marleen , Salgado, Roberto , Loi, Sherene , Carter, Jodi M. , Curigliano, Giuseppe , Criscitiello, Carmen , Cockenpot, Vincent , Lambertini, Matteo , Suman, Vera J. , Linderholm, Barbro Kristina , Martens, John W.M. , Deurzen, Carolien HM van, Shimoi, Tatsunori , Kim, Sung-Bae , Lee, Hee Jin , Dieci, Maria Vittoria , Bataillon, Guillaume , Vincent‐Salomon, Anne , André, Fabrice , Linn, Sabine C. , Goetz, Matthew P. , Michiels, Stefan

Cancer Research | March 2, 2023 | Volume: 83 | Issue: 5_Supplement | Pages: PD9-05-PD9-05

10.1158/1538-7445.sabcs22-pd9-05 Get It

Abstract Background: The prognostic value of stromal tumor-infiltrating lymphocytes (TILs) as a biomarker for triple-negative breast cancer (TNBC) has been extensively demonstrated in patients (pts) receiving (neo)adjuvant systemic therapy. In addition, several small studies suggest that a subset of pts with early-stage TNBC and high TILs have excellent long-term outcomes, even in the absence of systemic therapy [1-3]. However, data on the absolute risk of TNBC recurrence according to TIL levels in the absence of systemic therapy are limited and critical to inform the design of future systemic therapy de-escalation clinical trials. Methods: We conducted an individual patient data pooled analysis of 12 international cohorts of pts with TNBC treated with locoregional therapy but no systemic therapy. TNBC was defined as tumors with estrogen and progesterone receptor of < 1% and HER2 negative (IHC 0, 1+ or IHC 2+ and FISH negative) per local evaluation. TILs were locally assessed in hematoxylin & eosin-stained slides according to the International Immuno-Oncology Biomarker Working Group guidelines (www.tilsinbreastcancer.org). We used the Kaplan-Meier method to assess survival outcomes according to prespecified TIL thresholds: 30% and 50%. Confidence intervals (CI) for survival probabilities were calculated using a percentile bootstrap method. The primary endpoint was invasive disease-free survival (iDFS, STEEP 2.0 definition). Key secondary outcomes included recurrence-free survival (RFS), distant disease-free survival (DDFS) and overall survival (OS). Results: 1,835 pts diagnosed with TNBC between 1982 and 2017 who did not receive systemic therapy were included. The median age at diagnosis was 56 (IQR 38-71). Menopausal status was known in 1,184 women, of whom 78% were post-menopausal. The median tumor size was 2.0 cm (IQR 1.2-2.6). Most pts (87%) had no axillary lymph node involvement (N0). Most tumors were invasive ductal carcinoma (74%) and grade 3 (70%). The median level of TILs was 15% (IQR 5-40). The median duration of follow-up was 30.4 years (95% CI 29.9, 31.1). A total of 950 (52%) iDFS, 828 (45%) RFS, 767 (42%) DDFS events, and 604 (33%) deaths were observed. In multivariable analyses, higher TILs were independently associated with improved iDFS, RFS, DDFS, and OS beyond clinicopathological factors (likelihood ratio p< 10e-6). Each 10% increment in stromal TILs was associated with an 8% (95% CI: 6-11), 10% (95% CI: 7-13), and 13% (95% CI: 10-15) reduction in the risk of experiencing an iDFS, RFS or DDFS event, and with a 12% (95% CI: 9-15) reduction in the risk of death. iDFS, RFS, DDFS and OS rates according to different TIL thresholds and nodal status are shown in the Table. Of note, the RFS estimates (which exclude second non-breast primaries and contralateral breast cancers) were consistently higher than the iDFS counterparts (which include both), consistent with a high rate of contralateral breast cancers and second primary tumors in this cohort. Notably, patients with node-negative—and especially stage I—TNBC with high TILs had excellent survival rates at 10-year follow-up. Conclusion: TILs are highly prognostic in pts with systemically untreated early-stage TNBC. Pts with pN0 (and especially stage I) TNBC with high TILs exhibited very favorable long-term outcomes even in the absence of systemic therapy. These data define the natural history of TIL-rich TNBC pts and are crucial to identifying the optimal patient population for future chemotherapy and immunotherapy de-escalation clinical trials. References: [1] Leon-Ferre et al, 2017, PMID: 28913760 [2] Park et al, 2019, PMID: 31566659 [3] de Jong et al, 2022, PMID: 35353548 Table 5 and 10-year survival endpoints according TIL level, nodal status, and stage Citation Format: Roberto A. Leon-Ferre, Sarah Flora Jonas, Roberto Salgado, Sherene Loi, Vincent De Jong, Jodi M. Carter, Torsten Nielson, Samuel Leung, Nazia Riaz, Giuseppe Curigliano, Carmen Criscitiello, Vincent Cockenpot, Matteo Lambertini, Vera Suman, Barbro Linderholm, John WM Martens, Carolien HM van Deurzen, Mieke Timmermans, Tatsunori Shimoi, Shu Yazaki, Masayuki Yoshida, Sung-Bae Kim, Hee Jin Lee, Maria Vittoria Dieci, Guillaume Bataillon, Anne Salomon, Fabrice Andre, Marleen Kok, Sabine Linn, Matthew P. Goetz, Stefan Michiels. Stromal tumor-infiltrating lymphocytes identify early-stage triple-negative breast cancer patients with favorable outcomes at 10-year follow-up in the absence of systemic therapy: a pooled analysis of 1835 patients [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD9-05.
The path to a better biomarker: application of a risk management framework for the implementation of PD‐L1 and TILs as immuno‐oncology biomarkers in breast cancer clinical trials and daily practice
González-Ericsson, Paula I. , Stovgaard, Elisabeth Specht , Reisenbichler, Emily , Kos, Zuzana , Carter, Jodi M. , Michiels, Stefan , Quesne, John Le , Lænkholm, Anne‐Vibeke , Adam, Julien , Bartlett, John MS, Rimm, David L. , Quinn, Cecily , Cree, Ian A. , Hida, Akira I. , Haynes, Harry R. , Frahm, Isabel, Acosta‐Haab, Gabriela, Balancin, Marcelo Luiz , Bellolio, Enrique , Yang, Wentao , Kirtani, Pawan , Sugie, Tomoharu , Ehinger, Anna , Castaneda, Carlos, Kok, Marleen , McArthur, Heather L. , Siziopikou, Kalliopi P. , Fineberg, Susan , Gown, Allen M. , Viale, Giuseppe , Schnitt, Stuart J. , Pruneri, Giancarlo , Penault‐Llorca, Frederique, Hewitt, Stephen M. , Thompson, E. Aubrey , Allison, Kimberly H. , Symmans, W. Fraser , Bellizzi, Andrew M. , Brogi, Edi , Moore, David A. , Larsimont, Denis , Dillon, Deborah , Broeckx, Glenn , Bairi, Khalid El , Cimino‐Mathews, Ashley , Adams, Sylvia , Liu, S, Loibl, Sibylle , Chen, I‐Chun , Juco, Jonathan, Blackley, Elizabeth F. , Demaria, Sandra , Leon‐Ferre, Roberto A. , Zardavas, Dimitrios, Emancipator, Kenneth , Ely, Scott , Loi, Sherene , Salgado, Roberto , Group, International Immuno‐Oncology Biomarker Working, Cree, Ian , Haynes, Harry R , Balancin, Marcelo , Ehinger, Anna , Lazar, Alexander J , Broeckx, Glenn , El Bairi, Khalid , Leon-Ferre, Roberto, Gonzalez-Ericsson, Paula I , Bellizzi, Andrew M , Symmans, W Fraser , Loi, Sherene , Pruneri, Giancarlo , Rimm, David , Carter, Jodi , Sua, Luz Fernanda , Nielsen, Torsten O. , Fox, Stephen B. , Bartlett, John MS, Peeters, Dieter J. E. , Dieci, Maria Vittoria , Vincent‐Salomon, Anne , Balko, Justin M. , Badve, Sunil , Penault-Llorca, Frederique Madeleine , Lazar, Alexander J. , Lien, Huang‐Chun , Goetz, Matthew P. , Harbeck, Nadia , Sotiriou, Christos P. , Lakhani, Sunil R. , Denkert, Carsten , Gluz, Oleg , Sanders, Melinda E. , Group, International Immuno‐Oncology Biomarker Working

The Journal of Pathology | March 4, 2020 | Volume: 250 | Issue: 5 | Pages: 667-684

10.1002/path.5406 Get It

AbstractImmune checkpoint inhibitor therapies targeting PD‐1/PD‐L1 are now the standard of care in oncology across several hematologic and solid tumor types, including triple negative breast cancer (TNBC). Patients with metastatic or locally advanced TNBC with PD‐L1 expression on immune cells occupying ≥1% of tumor area demonstrated survival benefit with the addition of atezolizumab to nab‐paclitaxel. However, concerns regarding variability between immunohistochemical PD‐L1 assay performance and inter‐reader reproducibility have been raised. High tumor‐infiltrating lymphocytes (TILs) have also been associated with response to PD‐1/PD‐L1 inhibitors in patients with breast cancer (BC). TILs can be easily assessed on hematoxylin and eosin–stained slides and have shown reliable inter‐reader reproducibility. As an established prognostic factor in early stage TNBC, TILs are soon anticipated to be reported in daily practice in many pathology laboratories worldwide. Because TILs and PD‐L1 are parts of an immunological spectrum in BC, we propose the systematic implementation of combined PD‐L1 and TIL analyses as a more comprehensive immuno‐oncological biomarker for patient selection for PD‐1/PD‐L1 inhibition‐based therapy in patients with BC. Although practical and regulatory considerations differ by jurisdiction, the pathology community has the responsibility to patients to implement assays that lead to optimal patient selection. We propose herewith a risk‐management framework that may help mitigate the risks of suboptimal patient selection for immuno‐therapeutic approaches in clinical trials and daily practice based on combined TILs/PD‐L1 assessment in BC. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.