3D microtumors show promise for predicting treatment response in advanced colorectal cancer

MicroOrganoSpheres (MOS), tiny, three-dimensional tumor models produced in the laboratory from the tumor tissue of individual patients, could help predict which chemotherapy will be effective for patients with advanced colorectal cancer. A German-Dutch team tested MOS from tumor samples from 21 patients and found that in 83 percent of cases, the MOS's responses to drugs corresponded to the actual treatment success. When the MOS were obtained from the primary tumor rather than the metastases, the prediction accuracy was as high as 100 percent.

The microtumors are obtained from tumor cell suspensions, which are broken down into tiny droplets using microfluidics and embedded in a gel matrix. MOS can be tested automatically in a high-throughput process with various drugs, and modern image analysis and artificial intelligence are then used to measure how strongly the tumor cells respond to the respective drugs.

The droplet structures, which are approximately 300 micrometers in size, enable rapid growth, high reproducibility, and improved nutrient supply, surpassing conventional organoids in precision medicine and drug development. Compared to previous organoid methods, the test is standardized, can be automated, and can be performed within a few days.

Patients whose MOS responded to the chemotherapy tested in the laboratory remained disease-free for longer on average. The method was also able to reveal differences within a single tumor, thereby identifying particularly resistant groups of cancer cells.

The researchers said the method must first be further tested in larger patient groups in clinical trials. The findings were published in JCO Precision Oncology in 2026.