The future hope of “flash” radiation cancer therapy

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The goal of cancer therapy is to destroy the cancer cells while minimizing side effects and damage to the rest of the body. Common types of treatment include surgery, chemotherapy, targeted therapy and radiation therapy. Often combined with surgery or drugs, radiation therapy uses high-energy X-rays to harm the DNA and other critical processes of the rapidly-dividing cancer cells.

New innovations in radiation therapy were the focus of a recent episode of the Sirius radio show “The Future of Everything.” On hand was Stanford’s Billy Loo, MD, PhD, a professor of radiation oncology, who spoke with Stanford professor and radio host Russ Altman, MD, PhD.

Radiation has been used to treat cancer for over a century, but today’s technologies target the tumor with far greater precision and speed than the old days. Loo explained that modern radiotherapy now delivers low-dose beams of X-rays from multiple directions, which are accurately focused on the tumor so the surrounding healthy tissues get only a small dose while the tumor gets blasted. Radiation oncologists use imaging — CT, MRI or PET — to determine the three-dimensional sculpture of the tumor to target.

“We identify the area that needs to be treated, where the tumor is in relationship to the normal organs, and create a plan of the sculpted treatment,” Loo said. “And then during the treatment, we also use imaging … to see, for example, whether the radiation is going where we want it to go.”

In addition, oncologists now implement technologies in the clinic to compensate for motion, since organs like the lungs are constantly moving and patients have trouble lying still even for a few minutes. “We call it motion management. We do all kinds of tricks like turning on the radiation beam synchronized with the breathing cycle or following tumors around with the radiation beam,” explained Loo.

Currently, that is how standard radiation therapy works. However, Stanford radiation oncologists are collaborating with scientists at SLAC Linear Accelerator Center to develop an innovative technology called PHASER. Although Loo admits that the acronym was inspired because he loves Star Trek, PHASER stands for pluridirectional high-energy agile scanning electronic radiotherapy. This new technology delivers the radiation dose of an entire therapy session in a single flash lasting less than a second — faster than the body moves.

“We wondered, what if the treatment was done so fast — like in a flash photography — that all the motion is frozen? That’s a fundamental solution to this motion problem that gives us the ultimate precision,” he said. “If we’re able to treat more precisely with less spillage of radiation dose into normal tissues, that gives us the benefit of being able to kill the cancer and cause less collateral damage.”

The research team is currently testing the PHASER technology in mice, resulting in an exciting discovery — the biological response to flash radiotherapy may differ from slower traditional radiotherapy.

“We and a few other labs around the world have started to see that when the radiation is given in a flash, we see equal or better tumor killing but much better normal tissue protection than with the conventional speed of radiation,” Loo said. “And if that translates to humans, that’s a huge breakthrough.”

Loo also explained that their PHASER technology has been designed to be compact, economical, reliable and clinically efficient to provide a robust, mobile unit for global use. They expect it to fit in a standard cargo shipping container and to power it using solar energy and batteries.

“About half of the patients in the world today have no access to radiation therapy for technological and logistical reasons. That means millions of patients who could potentially be receiving curative cancer therapy are getting treated purely palliatively. And that’s a huge tragedy,” Loo said. “We don’t want to create a solution that everyone in the world has to come here to get — that would have limited impact. And so that’s been a core principle from the beginning.”

This is a reposting of my Scope blog post, courtesy of Stanford School of Medicine.

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Blasting radiation therapy into the future: New systems may improve cancer treatment

Image by Greg Stewart/SLAC National Accelerator Laboratory

As a cancer survivor, I know radiation therapy lasting minutes can seem much longer as you lie on the patient bed trying not to move. Future accelerator technology may turn these dreaded minutes into a fraction of a second due to new funding.

Stanford University and SLAC National Accelerator Laboratory are teaming up to develop a faster and more precise way to deliver X-rays or protons, quickly zapping cancer cells before their surrounding organs can move. This will likely reduce treatment side effects by minimizing damage to healthy tissue.

“Delivering the radiation dose of an entire therapy session with a single flash lasting less than a second would be the ultimate way of managing the constant motion of organs and tissues, and a major advance compared with methods we’re using today,” said Billy Loo, MD, PhD, an associate professor of radiation oncology at Stanford, in a recent SLAC news release.

Currently, most radiation therapy systems work by accelerating electrons through a meter-long tube using radiofrequency fields that travel in the same direction. These electrons then collide with a heavy metal target to convert their energy into high energy X-rays, which are sharply focused and delivered to the tumors.

Now, researchers are developing a new way to more powerfully accelerate the electrons. The key element of the project, called PHASER, is a prototype accelerator component (shown in bronze in this video) that delivers hundreds of times more power than the standard device.

In addition, the researchers are developing a similar device for proton therapy. Although less common than X-rays, protons are sometimes used to kill tumors and are expected to have fewer side effects particularly in sensitive areas like the brain. That’s because protons enter the body at a low energy and release most of that energy at the tumor site, minimizing radiation dose to the healthy tissue as the particles exit the body.

However, proton therapy currently requires large and complex facilities. The Stanford and SLAC team hopes to increase availability by designing a compact, power-efficient and economical proton therapy system that can be used in a clinical setting.

In addition to being faster and possibly more accessible, animal studies indicate that these new X-ray and proton technologies may be more effective.

“We’ve seen in mice that healthy cells suffer less damage when we apply the radiation dose very quickly, and yet the tumor-killing is equal or even a little better than that of a conventional longer exposure,” Loo said in the release. “If the results hold for humans, it would be a whole new paradigm for the field of radiation therapy.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

New way to understand tumor diversity combines CRISPR with genetic barcodes

Photo courtesy of PIXNIO

The growth of a particular tumor depends on multiple genetic factors, so it is difficult for cancer researchers to recreate and study this genetic diversity in the lab.

“Human cancers don’t have only one tumor-suppression mutation [which fuels tumor growth] — they have combinations. The question is, how do different mutated genes cooperate or not cooperate with one another?” said Monte Winslow, PhD, a Stanford assistant professor of genetics and of pathology, in a recent Stanford news release.

Now, Winslow and his colleagues have discovered a way to modify cancer-related gene and then track how these combinations of mutations impact tumor growth, as recently reported in Nature Genetics.

The researchers used a powerful gene-editing tool, called CRISPR-Cas9, to introduce multiple, genetically distinct tumors in the lungs of mice. They also attached short, unique DNA sequences to individual tumor cells — which acted as genetic barcodes and multiplied in number as the tumors grew. By counting the different barcodes, they were able to accurately and simultaneously track tumor growth.

“We can now generate a very large number of tumors with specific genetic signatures in the same mouse and follow their growth individually at scale and with high precision. The previous methods were both orders of magnitude slower and much less quantitative,” said Dmitri Petrov, PhD, a senior author of the study and an evolutionary biologist at Stanford, in the release.

The study showed that many tumor-suppressor genes only drive tumor growth when other specific genes are present. The researchers hope to use their new methodology to better understand why tumors with the same mutations sometimes grow to be very large in some patients and remain small in others, they said.

Their technique may also speed up cancer drug development, allowing a drug to be tested on thousands of tumor types simultaneously. Petrov explained in the release:

“We can help understand why targeted therapies and immunotherapies sometimes work amazingly well in patients and sometimes fail. We hypothesize that the genetic identify of tumors might be partially responsible, and we finally have a good way to test this.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Oncologist disagree on use of value to guide cancer treatments

Photo by Nick Youngson

Cancer care is expensive, with the cost of new chemotherapies exceeding  $100,000 annually and the growth in cancer care costs increasing faster than the growth in general medical care costs. In addition, there is a widely acknowledged mismatch between the costs and benefits of treatment.

“The pricing of cancer drugs doesn’t appear to be related to their health benefit. This is problematic and unaffordable both for the health care system and for patients, who are expected to engage in not-insubstantial cost sharing,” explained Risha Gidwani-Marszowski, DrPH, a health economist at the VA Palo Alto Health Care System and at Stanford.

In response to this gap, oncology professional societies now recommend that oncologists consider the value of a treatment when making clinical recommendations, a major shift in clinical practice. But how are oncologists defining whether a therapy has “high value?” And how are they using this information?

Gidwani-Marszowski investigated these questions in a new study recently published in Value in Health. Her multi-institutional research team conducted in-depth interviews with 31 U.S. oncologists who practiced in a diverse range of environments, including academic medical centers, community medical centers and the Veterans Health Administration.

The researchers asked oncologists open-ended questions about larger questions regarding value – specifically,  about the oncologists’ definitions and measurements of value, as well as about their value-based choices.

“We didn’t want to operate under the erroneous assumption that we knew everything there is to know about the relevant features of the value problem,” said Gidwani-Marszowski. “We felt it would be better to keep things open-ended, so that practicing oncologists could tell us the aspects of value that were most relevant or salient to them.”

Once these in-depth conversations were transcribed, two independent investigators qualitatively assessed the transcripts to identify themes — pinpointing and recording patterns. Their analyses revealed that oncologist have wide ranging views. Gidwani-Marszowski explained:

“One of the most interesting things we found through this work is that the divergent views exist at a very basic level — the definition of value.  For example, in defining value, some oncologists said cost was one of multiple factors that should be considered, while others said cost had no role at all to play in value.”

Additionally, some oncologists looked at cost in relation to a patient’s quality of life, while others looked at quality of life alone to measure value. One oncologist explained in the paper, “I think [value] shouldn’t just be measured by overall survival, but quality of life has to really be integrated into that. I’m extending the patient’s life by two months, if they’re filled with chemotherapy side effects and toxicity, have we increased the value?”

The oncologists also disagreed on how value should be measured, who should assess the value of a treatment and whether value should be discussed with the patient.

For one oncologist, conversations about costs are important: “I tend to explain to them what the cost is and what the benefit is. And some patients actually say, ‘I don’t think it’s worth it.’ … So I will give them [information about the] cost and the side effects and the benefit and we’ll make the decision together.”

For another oncologist, the conversations don’t work well: “Most of the time we don’t [discuss the cost of care] because then the patients and families think hey, these guys are looking at dollars and not providing the care… So that’s kind of really controversial. Plus it’s very uncomfortable even to talk about the money and the care we provide to them…”

Now, the team is using the results from these in-depth interviews to design a closed-ended survey, which they plan to disseminate to a large sample of oncologists across the country. Gidwani-Marszowski explained:

“Oncologists often have the best understanding of the effectiveness of a particular drug in a specific patient and largely guide the purchasing of care for cancer patients. Thus, it is partly through understanding their perspectives that we can improve the value of cancer care.”

Gidwani-Marszowski also told me that for value efforts to be successful, a critical first step is to make sure all of the relevant stakeholders — oncologists, patients, caregivers, other health care providers, payers, health economists and policy makers  — are able to reach a consensus on the definition of value in cancer care.  That will build a foundation for efforts to establish thresholds for value, mechanisms to measure value, and ultimately, efforts to improve the value of cancer care, she said.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Developing “guided missiles” to attack cancer: A podcast featuring a Stanford bioengineer

Photo by Allocer

Chemotherapy attacks cancer by killing cells that are rapidly dividing. But this leads to serious side effects, like intestinal upset and hair fallout, because these normal cells grow quickly.

So researchers like Jennifer Cochran, PhD, a professor and the chair of bioengineering at Stanford, are developing more targeted cancer therapies, dubbed “guided missiles.” She recently described her work to professor and radio show Russ Altman, MD, PhD, on an episode of the Sirius radio show The Future of Everything.

“We, and others, have developed novel proteins that can selectively target cancer cells and then we can attach cargo to them — this is where the missile analogy comes in,” Cochran told Altman. “The cargo that we attach, things like chemotherapy, can then be selectively targeted to the tumor.” The idea is to precisely deliver to the tumor a more poisonous dose than you could deliver systemically, she said.

One way to do this is to bioengineer antibodies, which are molecules that recognize and help neutralize foreign substances like bacteria. However, Cochran’s lab took a slightly different approach. She explained to Altman:

“As amazing as antibodies are, they can have some limitations in that they are very large in terms of molecular size so they have trouble wiggling into a tumor. So we’ve created smaller versions of tumor-targeting proteins that can hopefully penetrate into tumors better. And we’ve then chemically attached chemotherapy molecules to deliver a punch to the cancer cells.”

In order to develop these proteins, her team is expediting protein evolution in a test tube — making favorable properties that would normally evolve over millions of years happen in just a few weeks. To do this, the team uses genetic manipulation to create millions of slightly different protein variants, tests them with high-throughput screening in just a few hours, identifies the ones most desirable for a certain task, and then determines these variants’ DNA sequences.

For example, they used this evolutionary process on a peptide, a small fragment of protein, from the seeds of a plant known as a squirting cucumber to turn the molecule into a favorable drug scaffold. “We ran the protein through this evolution process to create a tumor-targeting protein that we then hooked the chemotherapy agents on to,” said Cochran.

Cochran’s group is also investigating immunotherapy applications for her proteins. She is teaming up with Dane Wittrup, PhD, a professor in chemical engineering and biological engineering at Massachusetts Institute of Technology, who has developed new ways to use the immune system. By combining Cochran’s tumor-targeting technology with Wittrup’s insights into immunotherapy, they are able to give a “one-two punch” and activate multiple factors of the immune system to more effectively attack cancer, she said.

Her research team is also interested in applying their work to other diseases. She explained to Altman:

“We’ve been applying them for cancer, but you can use the same approach to deliver therapies to other types of disease tissue. We have really only just scratched the surface of what we can do. A big driver of this has been the interdisciplinary culture of collaborative research at Stanford. We’ve been working together with physicians, clinicians, scientists, engineers and physicists to tackle really challenging problems.”

Cochran’s bioengineered proteins are not yet available to patients. However, some tumor-targeting molecules are already approved by the U.S. Food and Drug Administration and many more are in the pipeline. “There are a number of molecules that are FDA approved and you might have heard commercials for them,” she told Altman. “But they only work for a subset of patients. So the question is: how do we make them work better for a larger subset of patients?”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Living with cancer: A Q&A with comedian Fred Reiss

Photo by Ben Moon

Cancer isn’t what comes to mind when I think of stand-up comedy, but Fred Reiss may change that. A three-time cancer survivor, Reiss shares at Comedy Day 37 what it’s like to go for a follow-up PET scan to find out if your cancer is back, also joking that they found a computer chip in his neck and returned him to his original owner. I recently spoke with Reiss, who is also an inspirational wellness speaker and novelist, to learn more. 

When were you diagnosed and treated with cancer?

“I was diagnosed with testicular cancer when I was 28 in 1982. Then about 4 years ago, I was diagnosed again with testicular cancer and treated at Stanford — I should have gone for the 2-for-1 deal on testicular removal and saved myself some money. And then a year ago when going for a routine endoscope, I found out I had esophageal cancer. Fortunately Stanford caught it early, and it’s gone now with treatment. So I’ve had cancer three times. I guess I’ll keep on doing this until I get it right.

I started wearing boxing gloves to chemo during my second bout of testicular cancer. I thought of the scene in “Rocky” when he throws the first punch and knocks Apollo down in the first round. I kept thinking: I need to be in shape to throw that punch. I need to fight for my life. So I decided to wear boxing gloves. Why should I be self-conscious? And the first day, I had someone take a photo in a fighting stance with the gloves. The nurses loved that.”

Why do you do stand-up comedy?

“The genesis was when I was 28 with testicular cancer. I was lying there with an IV in my soft blue vein and I thought: If I’m here again, who will I be? Who will be lying in this bed? And I decided to move from the East Coast to California, go do stand-up comedy and write books.

Later, after I had cancer again, no one wanted to hire a two-time cancer survivor in his 50s to do comedy, radio, journalism, public relations or administration. I had to become Fred 2.0. So I thought, what do I have to say about going through all of this? And I headed back to the stage.

I started going to open mics to use the gravitas of my own mortality to help other people and explore myself. People in the audience wondered why I was there, because I’ve been on national TV, but you have to develop material at smaller clubs — the only way to find out if something works is by saying it. I’ve been on a billboard on Times Square to promote the film, “This is Living with Cancer.” That was the result of two to three years of going to open mics and working on material. I know I’m betraying myself if I don’t go out and perform. I’m betraying the person that I vowed to be.”

How did you become a cancer advocate?

“My cancer advocacy grew out of my suffering and watching other people suffering — it alters you. When I first had cancer, I went through self-actualization to figure out what I wanted to do. The second time, I thought about what I was going to do and what I’d done. And the third time, my ego was completely gone and I thought about other people.

So I decided to travel two tracks — comedy and cancer patient advocacy. I started doing “Fred talks” (my brand of motivational Ted-style talks) and speaking to hospital groups, offering myself to people. In comedy, the audience wants jokes. But if I’m speaking to groups, the audience wants to know how I feel; it’s enormously satisfying. If they can help me out financially when I speak, that’s great. But if they can’t afford it, I don’t mind speaking for free.

During my talks, I use jokes, personal anecdotes and photographs to tell my story of being diagnosed and at the end overcoming cancer. I stress how to draw on your personality, passion, humor and the character of your life to overcome it. I also give practical tips on how to reduce your suffering. My main message is that you can’t let cancer define you; you have to let the spirit that enabled you to overcome it be given to others to help them prevail over the disease too.

In that spirit, I still visit Stanford when I can, giving out my books, CDs and food. I can’t do it every day, but it’s a temple that I have to respect. It’s a way to pay homage and show that I haven’t forgotten the oncologists, nurses and all the people that made a difference. It’s not out of a sense of duty. These people did great things for me, so I’m trying to propel that toward the other people around me.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Stanford chemists produce chemical — originally from marine creature — needed for new drugs

Photo by Fitzgerald Marine Reserve Docent

One person’s weed is another’s flower. A good example of this is spiral-tufted bryozoan, an invasive marine organism that fouls up marine environments. Although considered a pest by many, spiral-tufted bryozoan is much sought after by researchers since it can produce biostatin 1 — a chemical critical to the development of promising new drugs to treat HIV/AIDS, Alzheimer’s disease and cancer.

Although this bryozoan is abundant, bryostatin 1 is very scarce because it’s difficult to harvest from the sea creature and complex to synthesize. In fact, the National Cancer Institute’s stock of bryostatin 1 is nearly depleted from supplying over 40 clinical trials. So Stanford chemists have developed a new, easier way to synthesize bryostatin 1, as recently reported in Science.

Paul Wender, PhD, a professor of chemistry and of chemical and systems biology at Stanford, has been working for years to develop bryostatin analogs that are more effective for drug development. However, the dwindling supply of bryostatin 1 inspired him to synthesize the drug itself.

“Ordinarily, we’re in the business of making chemicals that are better than the natural products,” Wender said in a recent Stanford news release. “But when we started to realize that clinical trials a lot of people were thinking about were not being done because they didn’t have enough material, we decided, ‘That’s it, we’re going to roll up our sleeves and make bryostatin because it is now in demand.’”

The researchers devised a much simpler synthesize process, cutting the steps down from 57 to 29. They also dramatically increased the yield, making it tens of thousands of times more efficient than extracting bryostatin from spiral-tufted bryozoan and significantly more efficient than the previous synthetic approaches. And they confirmed with a wide range of tests that their synthetic bryostatin was identical to a natural sample supplied by NCI.

So far, the team has produced over two grams of bryostatin 1, and a single gram can treat about 1000 cancer patients or 2000 Alzheimer’s patients, according to their paper. After scaling up production, they expect manufacturers to produce about 20 grams per year to meet clinical and research needs, Wender said in the news release.

They also expect their work could facilitate research using bryostatin analogs derived from their synthesis process. The paper explains that these analogs “are proving to be more effective and better tolerated in comparative studies with cells, disease models in animals, and ex vivo samples taken from HIV-positive patients.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.