Model tumors identify best drugs for bowel cancer before treatment
Researchers have created model tumors using the tissues of patients with advanced bowel cancer and used them to predict how the disease will respond to specific drug therapies – before treatment begins. Found to be 83% accurate, the pioneering approach would increase the chances that patients receive the most effective treatment at the earliest opportunity.
Bowel cancer is the second leading cause of cancer-related death worldwide despite an increasing number of treatment options. If caught early enough, the cancer can be treated successfully, but one of the biggest challenges is determining how a patient will respond to that treatment. A trial-and-error approach is taken for most therapies as no markers are available to predict response. As a result, patients can receive ineffective, costly, and toxic drugs.
In a pioneering study, researchers at the Walter and Eliza Hall Institute (WEHI) in Melbourne, Australia, developed a novel method of accurately predicting how a patient with advanced bowel cancer will respond to treatment – before they receive it.
“Each time you give a patient an ineffective treatment, you lose two to three months on something that won’t work,” said Peter Gibbs, a study co-author. “The window for successful treatment is often limited, so it is vital that we choose the options with the highest chance of success and avoid other treatments that are unlikely to work.”
The researchers created patient-derived tumor organoids (PDTOs), grain-of-sand-sized organs grown from a patient’s tumor tissues that mirror the features of the original tumor, from 30 patients in the advanced stages of bowel cancer. The PDTOs were then tested for their sensitivity to a range of cancer-fighting drugs.
“If a drug had no effect on the tumor organoid, then this treatment would also have no effect on the patient – and vice versa,” said Oliver Sieber, the study’s corresponding author. Our study showed organoid drug testing was able to predict treatment responses for study patients with a notable 83% accuracy. Importantly, pre-testing showed the therapies that won’t work with over 90% accuracy.”
The researchers’ testing included drugs not commonly used to treat bowel cancer. They found that two patient organoids were sensitive to a drug that’s often used in cases of breast and bladder cancer.
“Not only did we show that organoid drug testing could, for the first time, predict patient responses to bowel cancer treatment, we also managed to find a new therapeutic option for patients in our trial,” Sieber said. “That is the power of this incredible technology.”
The researchers’ work is being translated into a clinical trial that is expected to open at multiple Victorian hospitals later this year.
The study was published in the journal Cell Reports Medicine.