Although anti-cancer treatments have significantly advanced over the past decades, obstacles to accomplishing successful treatment still exist. The occurrence of treatment resistance is one of the... Show moreAlthough anti-cancer treatments have significantly advanced over the past decades, obstacles to accomplishing successful treatment still exist. The occurrence of treatment resistance is one of the major factors that limit the long-lasting efficacy of anti-cancer treatment. Additionally, substantial variability in pharmacokinetics (PK) / pharmacodynamics (PD) of anti-cancer drugs also challenges successful oncology treatment. Therefore, gaining knowledge of and ultimately better suppressing evolutionary resistance development during treatment, and applying personalized treatment are desired to improve anti-cancer treatment. In this thesis, we have applied quantitative modeling approaches to address these needs, aiming for improved treatment for oncology patients. Our work demonstrated that with the quantitative models, the evolutionary progression of tumors could be characterized and predicted, accounting for interactions among heterogeneous tumor cells and supported by mutant gene variants detected in circulating tumor DNA (ctDNA). In addition, we developed population PK /PD models which enabled quantitative description of the PK and PD of anti-cancer drugs and corresponding variabilities in real-world patients. The developed models have been further applied to support the identification of optimal treatment strategies and guide individualized treatment for oncology patients. Show less
In this thesis, different preclinical strategies were explored aiming at the identification of putative novel therapies for prostate and bladder cancer. The first part of this thesis (Chapter 2 and... Show moreIn this thesis, different preclinical strategies were explored aiming at the identification of putative novel therapies for prostate and bladder cancer. The first part of this thesis (Chapter 2 and Chapter 3) describes the generationof preclinical, patient-derived model systems of prostate and bladder cancer. In Chapter 2, an overview is provided of the most commonly used patient-derived model systems for urological tumors, and a framework on how these patient derived tumor models can be employed to address preclinical and clinical unmet needs is presented. In Chapter 3, we developed and optimized the culture of ex vivo tumor tissue slices and employed this model to detect anti-tumor responses of chemotherapeutic agents Docetaxel and Gemicitabin. Subsequently in Chapters 4, 5 and 6, we describe the use of multiple preclinical translational models, including patient-derived tumor models. In Chapter 4 and 5 the translational potential of the approved antipsychotic drug penfluridol was determined in bladder and prostate cancer. In Chapter 6, the use of oncolytic reovirus jin-3 as putative novel therapeutic strategy for the treatment of prostate is investigated. Finally, in Chapter 7, we describe a novel preclinical screening strategy based on E-cadherin (re)induction and inhibition of invasion for the identification of a new class of small molecules for the treatment of aggressive epithelial cancers. Show less
Transcriptome signature reversion (TSR) has been extensively proposed and used to discover new indications for existing drugs (i.e. drug repositioning, drug repurposing) for various cancer types.... Show moreTranscriptome signature reversion (TSR) has been extensively proposed and used to discover new indications for existing drugs (i.e. drug repositioning, drug repurposing) for various cancer types. TSR relies on the assumption that a drug that can revert gene expression changes induced by a disease back to original, i.e. healthy, levels is likely to be therapeutically active in treating the disease. Here, we aimed to validate the concept of TSR using the PRISM repurposing data set, which is-as of writing-the largest pharmacogenomic data set. The predictive utility of the TSR approach as it has currently been used appears to be much lower than previously reported and is completely nullified after the drug gene expression signatures are adjusted for the general anti-proliferative downstream effects of drug-induced decreased cell viability. Therefore, TSR mainly relies on generic anti-proliferative drug effects rather than on targeting cancer pathways specifically upregulated in tumor types. Show less
Court, J.R. de la; Bruns, A.H.W.; Roukens, A.H.E.; Bass, I.O.; Steeg, K. van; Toren-Wielema, M.L.; ... ; Heijmans, J. 2022
Introduction This guideline was written by a multidisciplinary committee with mandated members of the Dutch Society for Infectious Diseases, Dutch Society for Hematology, Dutch Society for Medical... Show moreIntroduction This guideline was written by a multidisciplinary committee with mandated members of the Dutch Society for Infectious Diseases, Dutch Society for Hematology, Dutch Society for Medical Oncology, Dutch Association of Hospital Pharmacists, Dutch Society for Medical Microbiology, and Dutch Society for Pediatrics. The guideline is written for adults and pediatric patients. Method The recommendations are based on the answers to nine questions formulated by the guideline committee. To provide evidence-based recommendations we used all relevant clinical guidelines published since 2010 as a source, supplemented with systematic searches and evaluation of the recent literature (2010-2020) and, where necessary, supplemented by expert-based advice. Results For adults the guideline distinguishes between high- and standard-risk neutropenia based on expected duration of neutropenia (> 7 days versus <= 7 days). Where possible a distinction has been made between pediatric and adult patients. Conclusion This guideline was written to aid diagnosis and management of patients with febrile neutropenia due to chemotherapy in the Netherlands. The guideline provides recommendation for children and adults. Adults patient are subdivided as having a standard- or high-risk neutropenic episode based on estimated duration of neutropenia. The most important recommendations are as follows. In adults with high-risk neutropenia (duration of neutropenia > 7 days) and in children with neutropenia, ceftazidime, cefepime, and piperacillin-tazobactam are all first-choice options for empirical antibiotic therapy in case of fever. In adults with standard-risk neutropenia (duration of neutropenia <= 7 days) the MASCC score can be used to assess the individual risk of infectious complications. For patients with a low risk of infectious complications (high MASCC score) oral antibiotic therapy in an outpatient setting is recommended. For patients with a high risk of infectious complications (low MASCC score) antibiotic therapy per protocol sepsis of unknown origin is recommended. Show less
Background Anti-cancer drugs commonly adversely affect fertility and sexual function. Despite this, patients report a lack of counselling of these potential adverse effects. The aim was to... Show moreBackground Anti-cancer drugs commonly adversely affect fertility and sexual function. Despite this, patients report a lack of counselling of these potential adverse effects. The aim was to determine Dutch oncologists' knowledge about the adverse effects of various cancer drugs on fertility and sexual function. Methods A cross-sectional survey was sent to members of the Dutch Society for Medical Oncology (n = 433). The survey questions included various cancer drugs' adverse effects on fertility, ovulation, spermatogenesis, and sexual function. Results One hundred and five of 392 oncologists responded (26.8%). Oncologists were more aware of the adverse effects on fertility compared to sexual function. Drugs that were mostly believed to negatively affect fertility were cisplatin (n = 81, 80.2%), epirubicin (n = 78, 78.0%) and cyclophosphamide (n = 80, 77.7%). Regarding sexual function, most mentioned drugs were tamoxifen (n = 67, 65.7%), GnRH-agonists (n = 64, 63.4%) and cisplatin (n = 58, 57.4%). Oncologists with expertise in urology possessed more awareness regarding sexuality-related adverse effects (cisplatin p = 0.038, etoposide p = 0.025, ifosfamide p = 0.06, vinblastine p = 0.000). Conclusion Results revealed that oncologists have different beliefs about possible sexual and fertility-related adverse effects concerning medication resources and literature. Based on our results, oncologists do not possess sufficient knowledge to inform patients about sexual and fertility-related adverse effects. Show less
Zaks, O.; Gaber, D.; Ben-Yaakov, K.; Sharvit-Bader, M.; Goz, A.; Rotfogel, Z.; ... ; Aharoni-Simon, M. 2021
Uveal melanoma (UM) and conjunctival melanoma (CM) are ocular malignancies that give rise to life-threatening metastases. Although local disease can often be treated successfully, it is often... Show moreUveal melanoma (UM) and conjunctival melanoma (CM) are ocular malignancies that give rise to life-threatening metastases. Although local disease can often be treated successfully, it is often associated with significant vision impairment and treatments are often not effective against metastatic disease. Novel treatment modalities that preserve vision may enable elimination of small tumors and may prevent subsequent metastatic spread.Very few mouse models of metastatic CM and UM are available for research and for development of novel therapies. One of the challenges is to follow tumor growth in-vivo and to determine the right size for treatment, mainly of the posterior, choroidal melanoma. Hence, the purpose of this study was to establish a simple, noninvasive imaging tool that will simplify visualization and tumor follow-up in mouse models of CM and UM.Tumors were induced by inoculation of murine B16LS9 cells into the sub-conjunctival or the choroidal space of a C57BL/6 mouse eye under a surgical microscope. Five to ten days following injection, tumor size was assessed by Phoenix MicronIVTM image-guided Optical Coherence Tomography (OCT) imaging, which included a realtime camera view and OCT scan of the conjunctiva and the retina. In addition, tumor size was evaluated by ultrasound and histopathological examination of eye sections.Tumor growth was observed 5-9 days following sub-conjunctival or sub-retinal injection of seven-thousand or seventy-thousand cells, respectively. A clear tumor mass was detected at these regions using the MicronIVTM imaging system camera and OCT scans. Histology of eye sections confirmed the presence of tumor tissue. OCT allowed an accurate measurement of tumor size in the UM model and a qualitative assessment of tumor size in the CM model. Moreover, OCT enabled assessing the success rate of the choroidal tumor induction and importantly, predicted final tumor size already on the day of cell inoculation.In conclusion, by using a simple, non-invasive imaging tool, we were able to follow intraocular tumor growth of both CM and UM, and to define, already at the time of cell inoculation, a grading scale to evaluate tumor size. This tool may be utilized for evaluation of new mouse models for CM and UM, as well as for testing new therapies for these diseases. Show less
Objective: To learn how to configure a patient communication aid (PCA) to facilitate shared decision-making (SDM) about treatment for advanced cancer.Methods: The PCA consists of education about... Show moreObjective: To learn how to configure a patient communication aid (PCA) to facilitate shared decision-making (SDM) about treatment for advanced cancer.Methods: The PCA consists of education about SDM, a question prompt list, and values clarification methods. Study 1. A first veersion was presented to 13 patients, 8 relatives and 14 bereaved relatives in interviews. Study 2. A second version was used by 18 patients in a pilot study. Patients and oncologists were interviewed, patients were surveyed, and consultations were audio-recorded.Results: Respondents reported that the aid facilitated patient control over information, raised choice awareness and promoted elaboration. Risks were identified, most importantly that the aid might upset patients. Also, some respondents reported that the PCA did not, or would not support decision making because they felt sufficiently competent, did not perceive a role for themselves, or did not perceive that the decision required elaboration.Conclusions: Opinions on the usefulness of the PCA varied. It was challenging to raise awareness about the presence of a choice, and to find a balance between comprehensive information and sensitivity.Practice implications: A future study should demonstrate whether the PCA can improve SDM, and whether this effect is stronger when oncologists receive training. (C) 2018 Elsevier B.V. All rights reserved. Show less
PurposeSentinel lymph node biopsy is an essential staging tool in patients with clinically localized oral cavity squamous cell carcinoma. The harvesting of a sentinel lymph node entails a sequence... Show morePurposeSentinel lymph node biopsy is an essential staging tool in patients with clinically localized oral cavity squamous cell carcinoma. The harvesting of a sentinel lymph node entails a sequence of procedures with participation of specialists in nuclear medicine, radiology, surgery, and pathology. The aim of this document is to provide guidelines for nuclear medicine physicians performing lymphoscintigraphy for sentinel lymph node detection in patients with early N0 oral cavity squamous cell carcinoma.MethodsThese practice guidelines were written and have been approved by the European Association of Nuclear Medicine (EANM) and the International Atomic Energy Agency (IAEA) to promote high-quality lymphoscintigraphy. The final result has been discussed by distinguished experts from the EANM Oncology Committee, and national nuclear medicine societies. The document has been endorsed by the Society of Nuclear Medicine and Molecular Imaging (SNMMI).These guidelines, together with another two focused on Surgery and Pathology (and published in specialised journals), are part of the synergistic efforts developed in preparation for the 2018 Sentinel Node Biopsy in Head and Neck Consensus Conference.ConclusionThe present practice guidelines will help nuclear medicine practitioners play their essential role in providing high-quality lymphatic mapping for the care of early N0 oral cavity squamous cell carcinoma patients. Show less
Sunitinib treatment requires a personalized approach, since patients can respond very differently to this drug. Pharmacogenetics may improve our ability to provide a tailored therapy by studying... Show moreSunitinib treatment requires a personalized approach, since patients can respond very differently to this drug. Pharmacogenetics may improve our ability to provide a tailored therapy by studying how genetic variations could influence drug response. The objective of this thesis was to find genetic markers that can predict toxicity and efficacy of sunitinib in patients with metastatic renal cell carcinoma. This research builds upon previous findings from candidate gene studies by testing a selection of SNPs based on plausible involvement in pharmacokinetics or pharmacodynamics of the drug of interest. We observed that SNPs located in genes involved in metabolism and drug absorption (CYP3A4, CYP3A5, and ABCB1) are potentially associated with the clearance of sunitinib and its active metabolite. In analogy to this, we confirmed SNP associations from previous studies for SNPs in CYP3A5 and ABCB1 that predict the need for dose reductions and improvement of PFS on sunitinib. Sunitinib-induced toxicity is possibly related to SNPs in CYP3A4 and CYP3A5, and in interleukin genes IL8 and IL13. VEGFR-2 (KDR) rs34231037 G-allele variant carriers were potentially associated with a favorable response to sunitinib. A GWAS learned us that SNPs in chromosome 21 are involved in sunitinib efficacy, probably by influencing drug resistance mechanisms. Show less
In recent years combination therapies have become increasingly popular in most therapeutic areas. We present a qualitative and quantitative approach and elucidate some of the challenges and... Show moreIn recent years combination therapies have become increasingly popular in most therapeutic areas. We present a qualitative and quantitative approach and elucidate some of the challenges and solutions to a more optimal ther- apy. For tumor growth this involves the study of semi-mechanistic cell-growth/kill models with multiple sites of action. We introduce such models and analyze their dynamic properties using simulations and mathematical analysis. This is done for two specific case studies, one involving a single compound and one a combination of two compounds. We generalize the notion of Tumor Static Concentration to cases when two compounds are in- volved and develop a graphical method for determining the optimal combination of the two compounds, using ideas akin to those used in studies employing isobolograms. In studying the dynamics of the second case study we focus, not only on the different concentrations, but also on the different dosing regimens and pharmacokinet- ics of the two compounds. Show less
Selection of patients who will likely respond or will develop relevant side effects has the potential to improve anticancer therapy. Considering the many contributing factors in drug disposition,... Show moreSelection of patients who will likely respond or will develop relevant side effects has the potential to improve anticancer therapy. Considering the many contributing factors in drug disposition, we hypothesized that variability in drug disposition could be better explained by phenotype, rather than by the genotype alone. In this thesis, phenotype tests in oncology were studied, with a focus on phenotype breath tests and CYP2D6 metabolism in breast cancer patients using tamoxifen. A review is given of phenotype studies published before 2011 addressing drug metabolizing enzymes in relation to anticancer drugs. The 13C-dextromethorphan-breath test was related to CYP2D6 genotype and serum concentrations of endoxifen, the active metabolite of tamoxifen. A 13C-dextromethorphan breath test was equally predictive of endoxifen levels as compared to the CYP2D6 genotype. We showed that there was no difference in CYP2D6 phenotype between metastasized patients and early breast cancer patients. Because endoxifen levels did not significantly differ between the two groups as well, our findings do not have clinical implications thus far. Show less
Currently, 35-45% of newly diagnosed breast cancer patients in developed countries is aged 65 years and older. Older women with breast cancer comprise a heterogeneous group due to large differences... Show moreCurrently, 35-45% of newly diagnosed breast cancer patients in developed countries is aged 65 years and older. Older women with breast cancer comprise a heterogeneous group due to large differences with regard to concomitant diseases, physiological reserve and functional status. Current guidelines for breast cancer are based on studies that were mostly performed in younger patients. Therefore, treatment of older women with breast cancer is not evidence-based, and it cannot be expected that clinical trials will fill this gap of knowledge in the near future. The aim of this thesis was to investigate several aspects of breast cancer treatment in older women. In Part I, several aspects of treatment in older breast cancer patients were assessed. Part II assessed methodological aspects of studying breast cancer in older patients. This thesis has shown that older patients are at increased risk for overdiagnosis of breast cancer due to population screening, with potential harmful effects due to the increased risk of complications of treatment. Despite changing treatment strategies, breast cancer prognosis of older women has not improved. Current treatment strategies and decisions tools are insufficient. Observational studies will become increasingly important in this patient population, the use of accurate methods will be essential. Show less
