Regenerated mini-tumors of cancer patients to test the success of the treatment

New breakthrough in the treatment of cancer?

The treatment of cancerous tumors is often extremely complicated and difficult. Researchers have now been able to test anti-cancer drugs on replica patient tumors. This allows physicians to determine in advance which medicines and treatments will work best. This could lead to a greatly improved treatment of cancer.

Researchers at the Institute of Cancer Research, London and the Royal Marsden NHS Foundation Trust found that artificially grown mini-tumors from biopsy specimens could be used to test the efficacy of drugs specifically for individual patients. The physicians published the results of their study in the English-language journal "Science".

Cancer is a disease that often leads to the death of those affected. With a new treatment method tumors can be combated more effectively in the future. (Image: vitanovski / fotolia.com)

Accuracy of the tests was between 88 and 100 percent

The exciting new technology enables the re-breeding of mini-tumors. This could help physicians, when treating patients with cancer, no longer have to try directly on the patient, which form of treatment is most effective. The experts found that testing on mini tumors with an accuracy between 88 and 100 percent predicted whether a drug would be effective.

Test helps to design an individual treatment scheme

For each patient, a suitable mini-tumor could be bred in the future, which is tested for its sensitivity to certain drugs before the start of treatment. This would enable physicians to design an individual treatment plan, the researchers explain.

Experts took biopsy samples from 71 subjects

The study was carried out with gastric and intestinal tumors and other cancers of the digestive system. The physicians took biopsy specimens from 71 patients with advanced bowel, gastric and esophageal or bile duct cancer whose tumors had already spread (metastasized) in the body.

55 drugs were tested on the mini-tumors

At an advanced stage of the disease, the scientists harvested cells by biopsy specimens, before and after treatment of metastatic sites. These were then embedded in a gel so that they could freely form a 3D shape. The scientists then tested 55 established or new drugs on the minitumor and compared the results to the patient's response in the clinic.

Non-effective drugs were 100 percent identified

The testing of drugs on the mini-tumors was 100 percent accurate in the identification of drugs that do not work in the patients. Accuracy in the selection of drugs that shrink the tumor was 88 percent, say the experts.

Mini-tumors very effective for predicting efficacy

Mini-tumors appeared to be more effective in predicting the drug response than analyzing the DNA code of the patient's tumor alone. Viewed under the microscope, the mini tumors had a strikingly similar mixture of different cell types as the original tumors in the patient. In-depth genetic analysis showed that the replicates also had the same pattern of genetic changes as the patients.

Bred tumors were 96 percent identical to the original tumors

In all patients, the original tumors and laboratory-grown minitumor were 96 percent identical across 151 cancer-related genes. There were very few new mutations after cultivating in a dish. This is critical because new mutations can alter the tumor's response to drugs, the authors explain.

Mini tumors developed in mice as well as their original

Mini tumors grown in trays, however, could not be used to test treatments targeting the environment of the tumor, such as the drug regorafinib, which restricts the blood supply to the tumor. However, when the mini-tumors were transplanted into mice, they responded to the same treatments and evolved over time, just like the patient's cancer, the researchers report.

Cancer treatments are a race against time

Once cancer has spread throughout the body and stops responding to standard treatments, a race against time begins, seeking a drug for patients that can slow the progression of the cancer and prolong its life, say the physicians. Reconstructing the tumors of patients in the laboratory with this new technique is a highly promising way to predict whether a drug is suitable for a patient. It was thus possible to study in detail how these tumors reacted to drugs, including the patterns of gene activity and gene mutation. It could even be checked how the cancer would develop in response to the treatment, the researchers explain.

Further clinical studies are needed

This technique could be applied to a variety of cancers in the future. The potential of this technique needs to be further evaluated in larger clinical trials, but it has the potential to contribute to a truly personalized treatment, the experts emphasize. Cancers are very complex and constantly adapt and evolve. Therefore, it is extremely difficult for physicians to predict whether a given drug will work for individual patients. However, the results of the study indicate that drugs could be tested on replica tumors before the drugs are given to the patient. With the help of these mini-tumors, it could even be predicted how a patient will react accurately. (As)