Drug testing on living tumor cells from patients can reveal potential therapeutic vulnerabilities in a tumor that are not always apparent through genetic analysis alone. These tests can help identify possible alternative treatment options when standard therapies are no longer effective.
In this study, up to 50 cancer drugs were tested on tumor models of various types of childhood and adult cancers. A rapid, short-term test measures the viability of tumor cells within three days after drug administration. A second method monitors the growth of mini-tumors in the laboratory, which develop from patient-specific tumor cells over a period of up to two weeks. The procedure also takes into account the uptake and cellular transport of the active ingredient, thereby providing insights into the long-term effects of the treatments.
The results showed a high degree of agreement between the two methods. In more than 96 percent of cases, the tests reached the same conclusion regarding which drugs are effective against a specific type of cancer and which are not. The long-term method, however, proved particularly valuable: It was able to distinguish whether a drug actually kills tumor cells or merely slows their growth temporarily. It also allowed for conclusions about how long-lasting a therapeutic effect is.
A clinical case study illustrated the significance of this approach: While the short-term test suggested a drug might be effective, the long-term analysis correctly predicted that the tumor would eventually start growing again.
The researchers view the combination of these two approaches as an important step toward even more precise and personalized cancer treatment. “Not every promising response in the lab leads to long-term therapeutic success. Our results show how important it is to monitor tumor responses over an extended period of time. This allows us to better distinguish which treatments have a genuine and lasting effect and which merely produce short-term effects,” says Ina Oehme, head of the study and of drug testing at the Hopp Children’s Cancer Center Heidelberg (KiTZ) and the German Cancer Research Center (DKFZ). Future studies will investigate how well the treatment responses observed in the laboratory can predict actual treatment success in patients.
Original publication:
A. Loboda et al. Integration and validation of complementary ex vivo assays for functional precision oncology. In: NPJ Precision Oncology (Online Publikation 17.06.2026). DOI: https://doi.org/10.1038/s41698-026-01555-2
