I attended the world's biggest cancer conference. Doctors gave standing ovations to 2 major breakthroughs.

Business Insider

11-06-2025

The biggest cancer conference in the world — ASCO — wrapped up earlier this month in Chicago.
Stunning new data suggested exercise, if done the right way, can be a colon cancer treatment.
AstraZeneca was a perennial star, with new uses for its drugs in early-stage disease.
Recently, I landed on what felt like another planet. Planet cancer research.
Technically, this planet was within the city of Chicago, inside the biggest convention center in North America, McCormick Place, which straddles two sides of a highway. It was filled to the brim with premier cancer experts from around the world.
At the American Society of Clinical Oncology (ASCO) annual meeting, 44,000 doctors, drugmakers, scientists, and patients, gathered both in person and online, spent four days collecting, sharing, and debating the best ways to prevent, treat, and attack cancer.
There were two big announcements that rose above the rest and brought attendees to their feet, cheering and clapping in appreciation.
Doctors were buzzing afterwards, with a few telling me they were inspired to think about new ways to treat their cancer patients. Both breakthroughs pave the way towards a smarter, more targeted future for treating and preventing all kinds of cancer.
1. Exercise outperformed expensive chemo in a groundbreaking trial
There was one talk at ASCO this year that stunned, invigorated, and even angered some doctors.
A team of Canadian scientists showed that a methodically-prescribed exercise routine, performed consistently three to four times per week, could outperform ongoing chemotherapy treatments for patients who'd had colon cancer and gone through initial treatment.
"This is so new and different and really incredible," Dr. Paul Oberstein, a medical oncologist specializing in gastrointestinal cancers at NYU Langone, told Business Insider at the conference.
Doctors routinely recommend exercise to their cancer patients, but there hasn't been a rigorous scientific trial studying the effects. Until now.
The researchers, from Queens University in Ontario, studied nearly 900 colon cancer patients in a gold-standard randomized trial. Each patient's cancer had been removed, and they'd gone through chemotherapy. The goal of the exercise program was to prevent high-risk stage 2 and stage 3 colon cancer from coming back, and to keep the patients alive.
Half of the patients, a control group, were given the same exercise advice that cancer patients often hear from their doctors.
The other half were written an exercise prescription. They were given a trainer or physical therapist who designed a personalized exercise regimen that each patient liked, and that they were likely to stick with for the three-year study. Some kayaked, others biked or swam, but most of the patients (median age of 61) embarked on just a few more walks each week — 45 to 60 minutes at a brisk pace.
After three years of prescribed, sustained exercise, patients saw results that were just as good as — in some cases better than — disease-free survival rates for the chemotherapy drugs that are typically used to treat cancer in this same context, to prevent recurrence. Oxaliplatin is a common colon cancer chemotherapy drug which costs $3,000 to $6,000 per treatment — cheap in the context of cancer care. The drug delivers an overall 10-year survival boost of 5%. The exercise program? 7% survival boost after eight years.
Patients who were just given the fitness advice had significantly more cancer recurrence, and more deaths than the exercise group.
"For every 16 patients exercising, exercise prevented one case of cancer," Chris Booth, a medical oncologist and the lead researcher of the study, said while presenting his results at ASCO. "For every 14 people that were on the exercise program, exercise prevented one person from dying."
Doctors attending ASCO were stunned. After Booth's presentation, a surge of excitement simmered through the crowd of oncologists. A standing ovation began slowly, then swelled to thunderous and enthusiastic sustained applause.
Some of the attendees wondered if this strategy could ever work for their own patients. Could they ever really be motivated to make this kind of change?
For Booth, the study provides a powerful lesson.
"Knowledge alone is likely to be insufficient to allow most people to make meaningful and sustained change," Booth said.
Exercise needs to be treated like a drug, he said. A prescription needs to be filled out, a trainer allotted, and a schedule adhered to.
Oberstein, the NYU Langone oncologist, told Business Insider that the panel had a profound impact on him. He's already talking internally about how his cancer center could implement this kind of program, perhaps with grants from major cancer philanthropy groups or patient support groups who would be willing to pay for tools like wearable trackers and virtual trainer sessions.
"It's a lot easier to get a drug that costs $200,000 a year," Oberstein said. "Than to get insurance or someone to pay for a trainer to help someone do exercise."
2. AstraZeneca's new immunotherapy drug stole the show
The other big insight in cancer treatment that shone through at ASCO was in immunotherapy. Doctors and drugmakers are starting to use these drugs to harness the immune system against earlier-stage cancers, with promising results.
The star of the show was drugmaker AstraZeneca, which had an impressive slate of top-level plenary talks geared toward using drugs earlier on for breast, gastric, and lung cancer survival.
The biggest splash I saw was from AstraZeneca's drug Imfinzi (durvalumab), which trains a patient's body to attack a protein in their cancer. Imfinzi's already routinely used in some late-stage, recurrent and metastatic cancers (in the treatment of solid lung and liver tumors, for example), but it hasn't been a go-to treatment for earlier-stage cancers.
In results from the company's late-stage phase-3 "Matterhorn" trial presented at the conference, Imfinzi, taken with chemo after surgery, boosted gastric cancer patients' two-year survival rates from 70% (without the immunotherapy) to nearly 76% — a significant jump.
The news — just one of AstraZeneca's big wins at the conference — highlights a growing trend in cancer treatment. Increasingly, drugmakers are pursuing early immune therapy treatments. These treatments can either complement — or even, in rare cases, completely replace — radiation and chemotherapy. The goal is to minimize the lifelong side effects of toxic cancer treatment (like lifelong organ damage and fertility issues) while also improving treatment outcomes.
In April, doctors at Memorial Sloan Kettering published results showing a monoclonal antibody treatment that's typically reserved for advanced-stage mismatch repair-deficient rectal tumors can completely replace chemo in earlier stages of disease.
"What was amazing, and is still amazing, is that all the patients in the rectal group had a complete response to just immunotherapy," Dr. Andrea Cercek, a medical oncologist at MSK, told BI during ASCO. "Everyone's organs were completely preserved — very minimal toxicity."
AstraZeneca senior vice president Mohit Manrao, head of the company's US oncology program, told BI that he envisions immunotherapy treatment as a great complement to traditional cancer treatment. Old-school treatments like chemotherapy and radiation go after cancer directly, aiming to kill cancer cells, while the newer drugs "engage the immune system to do better work."
"We cannot just keep treating metastatic cancer patients," Manrao told BI. "We've got to ensure, yes, we serve them, but we need to start getting into early disease where the possibility to cure is really, really high."