Posts

Roger Packer

All about neurology: Upcoming conferences led by Roger Packer, M.D.

Roger Packer

Roger Packer, M.D., senior vice president of the Center for Neurosciences and Behavioral Medicine at Children’s National Hospital, will speak at a series of symposiums in the next couple of months.

Most recently, he presented on pediatric brain tumor trials at a webinar hosted by the American Brain Tumor Association titled “Clinical Trials – Paving the Way Forward.” In case you missed it, you can watch it here.

For details on more upcoming presentations, see below:

On Friday, May 14, Dr. Packer will speak at the Cure Search for Children’s Cancer’s ‘Blurred Lines: Therapeutic vs. Research-only Biopsies,’ a session highlighting technologies, including liquid biopsies and single-cell sequencing, that have the potential to allow researchers to collect more data while decreasing the amount of tissue needed from solid tumor biopsies.

On Friday, May 28, he will give a virtual keynote address at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology during their “Pediatric oncology, hematology and immunology in 21st century: From research to clinical practice” online presentation. Dr. Packer will co-chair the session on central nervous system tumors and present on “CNS tumors: Major advances in neuro-oncology in last 10 years.”

And at the 50th Golden Anniversary Meeting of the Child Neurology Society, taking place September 29 to October 2, Dr. Packer will lead a symposium on new therapies for childhood medulloblastoma — the most common malignant brain tumor in children. Here, he will receive a recognition during the society’s annual gala honoring the “Founders of Child Neurology,” for his contribution in a new book in which Dr. Packer has a chapter outlining the history of child neurologists in the field of pediatric neuro-oncology.

Roger Packer at lectern

Roger Packer, M.D., presents keynote address at First International Pakistan Neuro-Oncology Symposium

Roger Packer at lectern

During his presentation, he addressed attendees on the topic of the “Modern Management of Medulloblastoma,” discussing results of recently completed clinical trials and the implications of new molecular insights into medulloblastoma, the most common childhood malignant brain tumor.

In late November 2020,  Roger Packer, M.D., senior vice president of the Center for Neurosciences and Behavioral Medicine at Children’s National Hospital, presented as the inaugural keynote speaker for the First International Pakistan Neuro-Oncology Symposium in Karachi, Pakistan.

During his virtual presentation, he addressed attendees on the topic of the “Modern Management of Medulloblastoma,” discussing results of recently completed clinical trials and the implications of new molecular insights into medulloblastoma, the most common childhood malignant brain tumor.

The symposium attracted participants from 57 countries across the globe. There were over 1,000 attendees and as a result of the success of this symposium, there is now a monthly pediatric neuro-oncology lecture series. Dr. Packer agreed to lecture again to the group in mid-January 2021 on “Pediatric Neural Tumors Associated with NF1” as part of an international lecture series hosted by the Aga Khan University in Pakistan.

This is one of multiple national and international activities led by the Brain Tumor Institute at Children’s National Hospital. Directed by Dr. Packer with Eugene Hwang, M.D. as his co-director, and who is associate division chief of oncology at Children’s National Hospital, the multidisciplinary institute holds a monthly tumor board for colleagues at Dmitry Rogachev National Research Center and the Burdenko Neurosurgery Institute in Moscow, Russia, and a monthly brain tumor board coordinated by the Pediatric Oncology Program for colleagues across São Paulo, Brazil.

This also leads to a bi-monthly regional tumor board, which is attended by staff of the National Cancer Institute, the University of Virginia, Inova Children’s Hospital, the University of Maryland Children’s Hospital, Children’s Hospital of Richmond at VCU, Children’s Hospital of The King’s Daughters Health System, Yale University, Geisinger Medical Center, Georgetown University and Carilion Clinic.

Research & Innovation Campus

Virginia Tech, Children’s National Hospital award $100,000 to fund collaborative cancer research pilot projects

Research & Innovation Campus

This pilot research program represents a growing academic research partnership between Children’s National and Virginia Tech. Last year, the two institutions announced that Virginia Tech will establish a biomedical research facility on the Children’s National Research & Innovation Campus.

Children’s National Hospital and Virginia Tech have awarded two $50,000 one-year pilot grants to multi-institutional teams of scientists for pediatric brain cancer research.

The inter-institutional program, which launched in December, promotes cross-disciplinary collaborations among researchers at both institutions. At Virginia Tech, the program is part of the Virginia Tech Cancer Research Alliance. Financial support for the program was provided by the Offices of the Physician-in-Chief and Chief Academic Officer at Children’s National, and by Virginia Tech’s Office of the Vice President for Health Sciences and Technology.

“We were delighted to see so many innovative and competitive research proposals for our first round of pilot grants in the area of brain cancer. By forging new research collaborations with our partners at Children’s National, we hope to make major strides in addressing one of the most common and devastating groups of cancers in children,” said Michael Friedlander, Virginia Tech’s vice president for health sciences and technology, and the executive director of the Fralin Biomedical Research Institute at VTC. “The pilot funding will bootstrap several programs to be able to acquire ongoing sustainable funding by providing the opportunity to test novel high impact ideas for new strategies for treating these disorders. There are simply too few good options for children in this space now and this partnership can change that for the better.”

The collaborative research initiative began through an agreement between the Fralin Biomedical Research Institute and the Children’s National Research Institute. The collaborative teams formed through a series of interactive discussions among Virginia Tech’s Cancer Research Alliance faculty members from the university’s Blacksburg and Roanoke campuses, and Children’s National’s neuro-oncology researchers.

“I am extremely excited by this collaboration between VT and CNH that is focused on pediatric brain tumors which is such an area of unmet need,” said Catherine Bollard, M.D., M.B.Ch.B.,, director of Children’s National’s Center for Cancer and Immunology Research. “I am confident that the funded proposals will soon advance our understanding of pediatric brain tumors and, more importantly, facilitate more joint efforts between two world-class institutions which is especially timely with the development of the Children’s National Research & Innovation Campus.”

Yanxin Pei, Ph.D., an assistant professor in the Center for Cancer Immunology Research at Children’s National, and Liwu Li, Ph.D., a professor of biological sciences in Virginia Tech’s College of Science, were awarded one of the pilot research grants to study how white blood cells called neutrophils are involved in metastatic MYC-driven medulloblastoma, an aggressive type of brain tumor in children that often resists conventional radiation and chemotherapies.

Yuan Zhu, Ph.D., the Gilbert Family Professor of Neurofibromatosis Research at Children’s National, and Susan Campbell, Ph.D., an assistant professor of animal and poultry sciences in Virginia Tech’s College of Agriculture and Life Sciences, were awarded funds to study glioma-induced seizures in mice with a genetic mutation that inhibits the production of P53, a key protein involved in suppressing cancer cell growth and division.

The successful applicants will receive funding starting this month and are expected to deliver preliminary data to support an extramural research application by 2024.

This pilot research program represents a growing academic research partnership between Children’s National and Virginia Tech. Last year, the two institutions announced that Virginia Tech will establish a biomedical research facility on the Children’s National Research & Innovation Campus. It will be the first research and innovation campus in the nation focused on pediatrics when it opens later this year and will house newly recruited teams of pediatric brain cancer researchers.

Liwu Li, Yanxin Pei, Susan Campbell, and Yuan Zhu

Liwu Li, Ph.D., Yanxin Pei, Ph.D., Susan Campbell, Ph.D., and Yuan Zhu, Ph.D., were awarded funding through the new pilot research program.

Roger Packer with patient

A lifetime of achievements: Roger Packer, M.D.

Roger Packer with patient

Over the years, Dr. Packer and his team in Washington, D.C., have made meaningful contributions to children all around the world diagnosed with childhood brain tumors, including medulloblastoma and gliomas.

Earlier in December, Roger Packer, M.D., senior vice president of the Center for Neurosciences and Behavioral Medicine at Children’s National Hospital, received the 2020 Lifetime Achievement Award from the International Symposium on Pediatric Neuro-Oncology at the meeting organized in Karuizawa, Japan. The prestigious recognition is a testament to the years of commitment and dedication Dr. Packer has devoted to the care of children with brain tumors and as such, have placed him as a top leader.

This award is a recognition of how the field has grown since the first International Symposium on Pediatric Neuro-Oncology Dr. Packer organized in Seattle in 1989. “It grew from a small gathering of investigators to now a multidisciplinary group of over 2,000 investigators,” Dr. Packer says.

Over the years, Dr. Packer and his team in Washington, D.C., have made meaningful contributions to children all around the world diagnosed with childhood brain tumors, including medulloblastoma and gliomas. These findings have contributed to an increase of the survival rate from 50% to over 80% for children with medulloblastoma. In addition, his contributions have led to newer molecular targeted therapies and improved the quality of life of children who are long-term survivors.

“The field, especially in the last decade, rapidly transitioned to a more biologically informed field,” Dr. Packer explains. “We are now utilizing new, exciting discoveries in biology and genetics to inform new approaches to treatment. This kind of transition gives us great hope for the future.”

In his early career, Dr. Packer worked with two neuro-oncology patients who died and would impact his decision to further study this field. At that time, there was minimal understanding of the nature of neuro-oncology diseases or how to best treat them. As a neurologist, he was frustrated by the lack of understanding and as a pediatrician, he was frustrated at the lack of ability to do success management.

“I saw this as a gap in my personal knowledge and found that the field was struggling to come up with new answers and new approaches,” he says. “But at the same time other, advances were being made in child cancer care, such as with leukemia. However, there was no wide focus on pediatric brain tumors.”

Combining his knowledge of neurology with his curiosity and relying on other leaders that surrounded him in the same field, Dr. Packer worked on driving this new work forward. Today, he is still heavily involved in the development of treatment protocols that are increasingly transitional for a variety of brain tumors, including low-grade and high-grade gliomas.

“With the help of our great colleagues at Children’s National, we continue to try to develop new means to treat these tumors, including immunological approaches and the incorporation in the use of novel means, such as low-intensity and high-intensity focused ultrasound,” he says. “We also have an excellent multidisciplinary team at Children’s National that has grown over the last decade some of whom are acknowledged national leaders in the fields of brain tumors, clinical research and clinical care. We also have a robust program focusing on the neurocognitive outcome of children and ways to intervene to ameliorate intellectual compromise and improve quality of life.”

Xanxin Pei

Dr. Yanxin Pei receives prestigious grant from V Foundation for Cancer Research

Xanxin Pei

When asked about this award, Dr. Pei noted “I am so deeply grateful to receive this support from the V Foundation for Cancer Research…I will use these resources to aid our goal of discovering new therapies to treat medulloblastoma.”

Yanxin Pei, Ph.D., assistant professor in the Brain Tumor Institute and the Children’s Research Institute at Children’s National Hospital in Washington, D.C., has recently been awarded a prestigious grant by the V Foundation for Cancer Research to support her groundbreaking work in finding new treatments for childhood medulloblastoma.

Dr. Pei, who joined Children’s National in 2014 after training in the Wechsler-Reya lab at the Sanford-Burnham Institute in La Jolla, CA, has focused her work on the biology of medulloblastoma, the most common malignant brain tumor in children, with a major emphasis on the study of the medulloblastoma subtype most resistant to treatment. Children with this form of medulloblastoma have less than a 30% chance of survival five years from their diagnosis.

Having already developed one of the most important mouse models of this disease, Dr. Pei’s present V Foundation for Cancer Research Award, which includes becoming a V scholar, will explore the role of metabolism in the development of metastasis in MYC-amplified medulloblastomas (the most virulent form of medulloblastoma).

The V Foundation for Cancer Research Award is one of a series of prestigious awards Dr. Pei has received over the past 18 months for her work, including an NIH-sponsored 5-year award (ROI) evaluating other aspects of medulloblastoma development and resistance to therapy, and grants from the Rally Foundation, the Meghan Rose Bradley Foundation and the Children’s Cancer Foundation.

When asked about this award, Dr. Pei noted “I am so deeply grateful to receive this support from the V Foundation for Cancer Research…I will use these resources to aid our goal of discovering new therapies to treat medulloblastoma.”

Her cutting-edge work is generating national and international attention and firmly places Dr. Pei as an international leader in medulloblastoma research.

pastel colored DNA strands

Germline microsatellite genotypes differentiate children with medulloblastoma

pastel colored DNA strands

A new study suggests that medulloblastoma-specific germline microsatellite variations mark those at-risk for medulloblastoma development.

Brian Rood, M.D., oncologist and medical director at the Brain Tumor Institute, and Harold “Skip” Garner, Ph.D., associate vice provost for research development at Edward Via College of Osteopathic Medicine, published a report in the Society for Neuro-Oncology’s Neuro-Oncology Journal about using a novel approach to identify specific markers in germline (non-tumor) DNA called microsatellites that can differentiate children who have the brain tumor medulloblastoma (MB) from those who don’t.

“Ultimately, the best way to save children from brain tumors and prevent them from bearing long-term side effects from treatment is to prevent those tumors from occurring in the first place,” says Dr. Rood. “New advancements hold the potential to finally realize the dream of cancer prevention, but we must first identify those children at-risk.”

While analyzing germline sequencing data from a training set of 120 MB subjects and 425 controls, the doctors identified 139 individual microsatellites whose genotypes differ significantly between the groups. Using a genetic algorithm, they were able to construct a subset of 43 microsatellites that distinguish MB subjects from controls with a sensitivity and specificity of 92% and 88% respectively.

“We made discoveries in an untapped part of the human genome, enabled by unique bioinformatics data mining approaches combined with clinical insight,” said Dr. Garner. “Our findings establish new genomic directions that can lead to high accuracy diagnostics for predicting susceptibility to medulloblastoma.”

What the doctors discovered and demonstrated in the study was that MB-specific germline microsatellite variations mark those at risk for MB development and suggest that other mechanisms of cancer predisposition beyond heritable mutations exist for MB.

“This work is the first to demonstrate the ability of specific DNA sequences to differentiate children with cancer from their healthy counterparts,” added Dr. Rood.

Contributing Authors to this research study included:  Brian R. Rood, M.D., Harold R. Garner, Ph.D., Samuel Rivero-Hinojosa, Ph.D., and Nicholas Kinney, Ph.D.

Eugene Hwang in an exam room

Clinical Trial Spotlight: Creating a super army to target CNS tumors

Eugene Hwang in an exam room

Following the noted success of CAR-T cells in treating leukemia, Eugene Hwang, M.D., and a team of physicians at Children’s National are studying the efficacy of using these white blood cell “armies” to fight central nervous system (CNS) tumors.

Following the noted success of CAR-T cells in treating leukemia, physicians at Children’s National are studying the efficacy of using these white blood cell “armies” to fight central nervous system (CNS) tumors. Employing a strategy of “supertraining” the cells to target and attack three tumor targets as opposed to just one, Eugene Hwang, M.D., and the team at Children’s are optimistic about using this immunotherapy technique on a patient population that hasn’t previously seen much promise for treatment or cure. The therapy is built on the backbone of T cell technology championed by Catherine Bollard, M.B.Ch.B., M.D., director of the Center for Cancer and Immunology Research, which is only available at Children’s National. Hwang sees this trial as an exciting start to using T cells to recognize resistant brain cancer. “We have never before been able to pick out markers on brain cancer and use the immune system to help us attack the cancer cells. This strategy promises to help us find treatments that are better at killing cancer and lessening side effects,” he says.

This Phase 1 dose-escalation is designed to determine the safety and feasibility of rapidly generated tumor multiantigen associated specific cytotoxic T lymphocytes (TAA-T) in patients with newly diagnosed diffuse intrinsic pontine gliomas (DIPGs) or recurrent, progressive or refractory non-brainstem CNS malignancies. Pediatric and adult patients who have high-risk CNS tumors with known positivity for one or more Tumor Associated Antigens (TAA) (WT1, PRAME and/or surviving) will be enrolled in one of two groups: Group A includes patients with newly diagnosed DIPGs who will undergo irradiation as part of their upfront therapy and Group B includes patients with recurrent, progressive or refractory CNS tumors including medulloblastoma, non-brainstem high-grade glioma, and ependymoma, among others. TAA-T will be generated from a patient’s peripheral blood mononuclear cells (PBMCs) or by apheresis. This protocol is designed as a phase 1 dose-escalation study. Group A patients: TAA-T will be infused any time >2 weeks after completion of radiotherapy. Group B patients: TAA-T will be infused any time >2 after completing the most recent course of conventional (non-investigational) therapy for their disease AND after appropriate washout periods as detailed in eligibility criteria.

For more information about this trial, contact:

Eugene Hwang, M.D.
202-476-5046
ehwang@childrensnational.org

Click here to view Open Phase 1 and 2 Cancer Clinical Trials at Children’s National.

The Children’s National Center for Cancer and Blood Disorders is committed to providing the best care for pediatric patients. Our experts play an active role in innovative clinical trials to advance pediatric cancer care. We offer access to novel trials and therapies, some of which are only available here at Children’s National. With research interests covering nearly aspect of pediatric cancer care, our work is making great advancements in childhood cancer.

Eugene Hwang

Unexpected heterogeneity in CNS-PNET patients treated as a single entity

Eugene Hwang

“We found that some patients diagnosed with standard tools underwent much more treatment than necessary or intended,” said Eugene Hwang, M.D.

Eugene I. Hwang, M.D., a neuro-oncologist in the Center for Cancer and Blood Disorders, and other researchers at Children’s National Health System, Seattle Children’s Hospital and Research Institute, the Fred Hutchinson Cancer Research Center and the Hopp-Children’s Cancer Center at the NCT Heidelberg recently published the results of a clinical trial focusing on children with histologically diagnosed supratentorial primitive neuroectodermal tumors (CNS-PNET) and pineblastomas (PBLs).

The clinical trial, published online October 17, 2018 in the Journal of Clinical Oncology, included children and adolescents aged 3-22 with these brain cancers who were randomly assigned to receive carboplatin during radiation and/or isotretinoin after the standard intensive therapy (high-dose craniospinal radiation and months of inpatient chemotherapy).  Importantly, because each patient was treated prospectively according to the clinical trial design, the conclusions related to tumor biology were felt to be less affected by varied treatment plans.

“This trial really highlighted the importance of new molecular testing methods in accurately diagnosing some of the brain cancers included in the trial. We found that some patients diagnosed with standard tools underwent much more treatment than necessary or intended.” says Dr. Hwang. “Kids who aren’t receiving the right form of cancer treatment may not get better despite months and months of intensive treatment.”

During this clinical trial, 85 participants with institutionally-diagnosed CNS-PNETs/PBLs were enrolled. Out of the 60 patients with sufficient tissue, 31 were non-pineal in location, 22 of which represented tumors that did not fit in the diagnoses intended for trial inclusion.

The researchers discovered that patient outcomes across each molecularly-diagnosed tumor type were strikingly different. Patients with molecularly-confirmed supratentorial embryonal tumors/PBLs exhibited a five-year event free survival (EFS) and an overall survival rate of 62 percent and 78.5 percent, respectively. However, patients with molecularly-classified high-grade gliomas (HGGs) had a five-year EFS of 5.6 percent and OS of 12 percent, showing no benefit even with the chemotherapy and craniospinal radiation.

Researchers determined that for patients with CNS-PNETs/PBLs, prognosis is considerably better than previously assumed when molecularly-confirmed HGG are removed. Dr. Hwang and co-authors concluded that molecular diagnosis can greatly aid standard pathological diagnostic tools, preventing unnecessary intensive therapy for some patients while enabling more rational treatment for others.

“The findings from our clinical trial have highlighted the immense challenges of histology-based diagnosis for some types of pediatric brain tumors, and the enormous importance this has for children with brain cancer,” Dr. Hwang says. “We hope that ultimately our study will pave the way for molecular profiling to become a standard component of initial diagnosis.”

Yuan Zhu

The brain tumor field moves forward with new findings and a research grant

Yuan Zhu

Yuan Zhu, Ph.D., and other experts completed new research findings evaluating the effects of manipulating the growth-promoting signaling pathways in brain tumors associated with adults and children.

This month, experts at Children’s National Health System made great strides in brain tumor research, specifically in gliomas, glioblastomas and medulloblastomas. Led by Yuan Zhu, Ph.D., the scientific director and Gilbert Endowed Professor of the Gilbert Family Neurofibromatosis Institute and Center for Cancer and Immunology Research at Children’s National, the team completed new research findings evaluating the effects of manipulating the growth-promoting signaling pathways in brain tumors associated with adults and children. Dr. Zhu’s research was recently published in Cell Reports and he was also awarded a U.S. Department of Defense (DoD) grant to gain a better understanding of how low-grade gliomas form. Together, this work moves the needle on developing more effective treatments for these debilitating and life-threatening tumors.

The study

In his recently published paper, Dr. Zhu and his colleagues, including Drs. Seckin Akgul and Yinghua Li, studied glioblastomas, the most common brain tumor in adults, and medulloblastomas, the most common brain tumor found in children, in genetically engineered experimental models. Dr. Zhu found that when they removed the p53 gene (the most commonly mutated tumor suppressor gene in human cancers) in the experimental model’s brain, most developed malignant gliomas and glioblastomas, while Sonic Hedgehog (SHH)-subtype (SHH) medulloblastomas were also observed. They further suppressed the Rictor/mTorc2 molecular pathway that is known in the regulation of tumor growth. This action greatly reduced the incidence of malignant gliomas and extended the survival of the models, validating the concept that Rictor/mTorc2 could be a viable drug target for this lethal brain cancer in adults.

The study also found that the same Rictor/mTorc2 molecular pathway serves the opposite function in SHH medulloblastoma formation, acting as a tumor suppressor. Findings suggest that if the same drug treatment is used for treating SHH medulloblastoma in children, it could potentially have an adverse effect and promote growth of the tumors.

Ultimately, the study demonstrates that Rictor/mTORC2 has opposing functions in glioblastomas in adults and SHH medulloblastomas in children. While drug therapies targeting Rictor/mTORC2 may be successful in adults, the findings reveal the risks of treating children with pediatric brain tumors when using the same therapies.

The grant

Continuing the study of brain tumors, Dr. Zhu recently received a $575,000 grant from DoD to research benign gliomas, with the hope of gaining a greater understanding of how the tumors form. Low-grade gliomas, or benign brain tumors, are the most common brain tumors in children. While not lethal like their high-grade counterpart, these tumors can lead to significant neurological defects, permanently impacting a child’s quality of life. Most commonly, the tumor can impair vision, often leading to blindness.

Since the tumors only occur in children under the age of eight, Dr. Zhu believes they are linked to neural stem or progenitor cells that exist in the optic nerve only during development, or when children are under eight-years-old. To test if his hypothesis is correct, Dr. Zhu will develop a preclinical model that mimics human brain tumors to study the development of the optic nerve. If his theory proves correct, Dr. Zhu’s long-term goal is to develop a strategy that prevents the tumor formation from ever occurring, ultimately preventing vision loss in children. The grant begins in July and will run for three years.

 

Brian Rood

Improving the understanding of medulloblastoma

Brian Rood

Brian Rood, M.D., employed quantitative proteomics to tumor samples that led to novel therapeutic targets for Medulloblastoma and other tumors.

In a recently published study, Brian Rood, M.D., a neuro-oncologist at Children’s National Health System, employed quantitative proteomics to tumor samples, a technique that could lead to novel therapeutic targets for medulloblastoma and other tumors in the future.

Currently, many experts use genomic characterization to understand the genetic makeup of cancer cells, which has deepened the field’s collective knowledge of tumor biology. However, it has remained challenging to infer specific information about how the tumors will respond and consequently develop more effective therapies. Medulloblastoma is the most common pediatric, malignant brain tumor. Through Dr. Rood’s research using proteomic analysis, he was able to identify and measure the protein makeup of medulloblastoma, which led to a potential pathway for clinical intervention to treat this life-threatening cancer. The findings were published online June 7, 2018, in Acta Neuropathologica Communications.

“The goal of this research was to find out how these tumor cells function at the protein level, which may ultimately help the field identify drug therapies to stop them,” says Dr. Rood. “The genes of a cancer cell are like a blueprint for a building, but the blueprints aren’t always followed in a cancer cell: Not every active gene will produce its corresponding protein. Proteins do the work of the cell, and understanding them will provide a better overall understanding of a cancer cell’s biology.”

Dr. Rood compared proteomic and genomic data to confirm that genetics do not accurately predict the quantity of proteins. By directly quantitating the proteins and comparing them between different subgroups of the disease, they were able to identify protein-based pathways driving tumor biology. With this information, Dr. Rood was able to demonstrate that medulloblastoma depends on a crucial pathway, the eukaryotic initiation factor 4F protein synthesis pathway, resulting in the identification of a potential target for new treatments in medulloblastoma.

Ultimately, Dr. Rood found that proteomic analysis complements genomic characterization and the two can be used together to create a more complete understanding of tumor biology. Going forward, he hopes proteomic analysis will become common practice for studying all tumors, allowing tumors to be categorized and grouped together by protein makeup to help the field identify more effective therapies for all tumors.