ASCO 2025: diet and colon cancer, improving prostate cancer treatment and liquid biopsies target breast cancer

From 30 May-2 June 2025, the world’s cancer researchers were in Chicago for the year’s biggest cancer conference: the American Society of Clinical Oncology (ASCO) annual meeting. We sorted through their studies to bring you some highlights.

Can a healthy diet help more people survive colon cancer? 

One of our headline-making studies at ASCO showed that exercise can help stop colon cancer coming back after treatment. Another study, from a team in the US, suggests that healthy eating also has a big part to play. 

Previous research has linked chronic inflammation, which can be influenced by diet, to colon cancer risk. Just as our team did with exercise, researchers on this study looked at it from the other side, investigating the impact of pro-inflammatory and anti-inflammatory diets on outcomes after treatment. 

Pro-inflammatory diets include more things that can overstimulate the immune system, like sugary drinks, red meat, processed meats and refined grains (like white bread and white rice). Anti-inflammatory diets have the opposite effect. They include more coffee and tea, along with leafy green vegetables, nuts and fatty fish.

Although diet didn’t make a significant difference to the risk of cancer returning, the study found that people with less inflammatory diets were more likely to live longer. 

The results show that people with the most inflammatory diets had an 87% higher risk of death than people with the least inflammatory diets. 

Overall, people who kept to less inflammatory diets and exercised regularly were the most likely to survive.

Dr Catherine Elliott, our director of research, said: “This study adds to interesting emerging evidence about the role of inflammation in the progression of colon cancer. We need more high-quality research like this to help us uncover more about how our diet influences cancer outcomes.  

“When it comes to food and cancer risk, our overall diet is far more important than any single food or ingredient. A healthy, balanced diet includes eating lots of fruit, vegetables, wholegrains, and healthy sources of protein like beans and chicken. Cutting down on processed and red meats, and foods high in fat, sugar and salt also helps.” 

Immunotherapy stops more head and neck cancers coming back

After decades with very few advances in head and neck cancer treatment, the immunotherapy drug pembrolizumab (Keytruda) is beginning to turn the tide. 

The drug, which stops cancer cells suppressing the immune system, has already become an option for some people with head and neck cancers that can’t be surgically removed. Now, research presented at ASCO has shown that it can also be used alongside surgery to improve how we treat the disease before it spreads. 

The KEYNOTE-689 study added pembrolizumab at the beginning and end of standard treatment for locally advanced head and neck cancers. On average, that stopped people’s cancers coming back for more than four years, compared to two-and-a-half years for those who only received standard care. 

Most of the 714 patients on the trial also had cancers that were especially vulnerable to pembrolizumab. For this group, the drug almost doubled the average time it took for a cancer to return to five years.

For all patients, the drug also reduced the risk of the cancer spreading to another part of the body and of any new cancers starting.

Though we didn’t fund this work directly, one of our funded scientists, Professor Kevin Harrington, led the UK part of the 24-country trial at the Institute of Cancer Research (ICR). He talked the BBC through the treatment approach, saying: “We give the immune system the chance to have a good look at the tumour to generate anti-tumour immunity and then, after removal of the tumour, we continue to amplify that immune response by giving the drug continually for up to a year.”

He added: “This research shows that immunotherapy could change the world for these patients. It significantly decreases the chance of cancer spreading around the body, at which point it is incredibly difficult to treat.”

CAR-T cell therapy shows first signs of success in solid tumours 

CAR-T cell therapy is a more personalised type of immunotherapy than pembrolizumab. It involves immune cells called T cells being genetically modified to recognise specific features of cancer cells. This is done by adding CARs, or chimeric antigen receptors. 

Though CAR-T cell therapy has revolutionised how we treat some blood cancers, it’s yet to prove effective for solid tumours. 

Results presented at ASCO by a team based in China suggest that may be changing. In the first randomised clinical trial of CAR-T cell therapy, researchers found that the treatment could push up survival for people with advanced stomach or gastro oesophageal (GOJ) cancer.

In the trial, patients whose cancers had kept growing or come back after two treatments were randomised to receive either another standard treatment or CAR-T cell therapy. Those who received CAR-T cell therapy lived an average of almost eight months, compared to five-and-a-half months for people who received standard care, a 40% increase. They also went more than three months before cancer progression, compared to less than two months for the standard treatment group. 

“It’s encouraging to see early signs that CAR-T cell therapy might help people with advanced stomach or gastroesophageal junction cancer,” said Elliott. ”While this is a modest improvement, it could mark an important step forward for patients with limited treatment options. Further trials will now be needed to confirm whether this treatment is beneficial.” 

An AI test to direct prostate cancer treatment 

For almost 15 years, abiraterone, which was discovered, developed and trialled by our researchers, has made it possible for some men with incurable prostate cancer to live long healthy lives with the disease under control.

More recently, our STAMPEDE trial also showed that it could also help treat men with high-risk cancers that haven’t yet begun to spread.  

Abiraterone is now used that way by the NHS in Scotland and Wales but not in England – partly because it’s hard to tell who in this group will benefit from receiving the drug on top of standard treatment.

Results presented at ASCO suggest artificial intelligence (AI) can help resolve that issue. Using a new AI test on data from STAMPEDE, researchers at the ICR found that abiraterone can halve the risk of death for 25% of men with high-risk prostate cancers that haven’t spread. For the other 75%, whose chances of survival are already much better with standard care, abiraterone’s benefits weren’t statistically or clinically significant.

The test was able to separate the two groups by investigating images of 1,000 men’s tumour samples taken as part of STAMPEDE. Cancers that needed to be treated with abiraterone had patterns of warning signs (biomarkers) invisible to human eyes.

The study’s results suggest that abiraterone could be approved for a smaller group of men than previously thought, allowing the NHS to use the drug most effectively at the lowest cost.

Keeping advanced prostate cancers with BRCA mutations in check 

Early results from another study at ASCO suggest that combining abiraterone with a drug called niraparib could be a way to make treatment more effective for some men with advanced prostate cancer that has spread to another part of the body. 

Niraparib is a type of PARP inhibitor, a drug that interferes with how cancer cells driven by mutations to BRCA genes (among some other types) repair damage. Through BRCA stands for breast cancer, faults in these genes, which often run in families, can also increase people’s risk of prostate cancer. BRCA gene mutations can also make cancers more aggressive and harder to treat with tools like chemotherapy, which is why our work to develop the first PARP inhibitors in the 1990s and early 2000s was such a significant step forward for targeted cancer drugs.  

Through its first two-and-a-half years, the phase 3 AMPLITUDE study showed that, across all patients, adding niraparib to abiraterone cut the risk of prostate cancers continuing to grow by more than a third. In patients who also had BRCA1 or BRCA2 mutations, the risk of the cancer growing was almost halved. 

“Every day, around 150 people are diagnosed with prostate cancer in the UK,” said Elliott. “When cancer spreads and becomes metastatic, treatment options are more limited - that’s why research like this is so important to find new ways to tackle the disease.”  

AMPLITUDE follows on from the MAGNITUDE trial, which showed the same treatment combination worked in patients who had a later form of advanced prostate cancer and the same genetic alterations. 

Nonetheless, the trial isn’t without its concerns. 75% of patients who received niraparib with abiraterone in AMPLITUDE experienced serious or life-threatening side effects, compared to 59% of those who received abiraterone and a placebo. As a result, more patients in the niraparib group ended their treatment early.  

“Results from this trial show promising signs that adding niraparib to abiraterone for people with BRCA mutations could slow down cancer growth and prevent it from spreading further,” said Elliott.  

“This highlights the value of using genetic information to guide more personalised and effective treatment, but it’s still too early to say whether this combination will help patients live longer overall.” 

Liquid biopsies and targeted therapies keep breast cancers at bay

Two studies involving a team at the ICR have combined new drugs with cancer tracking blood tests called liquid biopsies to improve treatment for advanced breast cancers. 

Both looked at breast cancers with high levels of hormone receptors and low levels of the growth protein HER2.  

Around 7 in 10 women with breast cancer have these HR-positive (HR+), HER2-negative (HER2-) forms of the disease. When they grow and spread, they’re usually treated with two drugs: a hormone therapy and a targeted growth blocker, but, in some cases, they can develop mutations that can help keep growing.  

By spotting those mutations with liquid biopsies and either adding a new drug or swapping one in to counter them, the INAVO120 and the SERENA-6 studies were able help more people with advanced breast cancers survive for longer. There’s more on both studies in the box below.