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Re-grown mini-tumors from cancer patients to test the success of treatment


Breakthrough in cancer treatment?

The treatment of cancer tumors is often extremely complicated and difficult. Researchers have now succeeded in testing cancer drugs on replicas of patients' tumors. This allows medical professionals to determine in advance which drugs and treatments will work best. This could lead to a much improved treatment for cancer.

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

The accuracy of the tests ranged from 88 to 100 percent

The exciting new technology enables mini-tumors to be grown. This could help medical professionals no longer have to try out which form of treatment is most effective when treating cancer patients. The experts found that tests on mini tumors predicted whether a drug would be effective with an accuracy between 88 and 100 percent.

Test helps to design individual treatment regimens

A suitable mini-tumor could be cultivated for each patient in the future, which will be tested for sensitivity to certain medications before the start of treatment. Doctors could then design an individual treatment regimen, the researchers explain.

Experts took biopsy samples from 71 subjects

The study was performed on gastric and intestinal tumors and other digestive system cancers. The doctors took biopsy samples from 71 patients with advanced colorectal, gastric and esophageal or biliary tract cancer whose tumors had already spread (metastasized) in the body.

55 drugs were tested on the mini tumors

In an advanced stage of the disease, the scientists removed cells using biopsy samples, before and after the 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 mini tumors and compared the results with the patient's reaction in the clinic.

Inactive drugs were identified 100 percent

Testing drugs on the mini-tumors was 100 percent accurate in identifying drugs that didn't work for patients. According to the experts, the accuracy of the selection of drugs that shrank the tumor was 88 percent.

Mini tumors very effective in predicting effectiveness

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

Bred tumors were 96 percent similar to the original tumors

In all patients, the original tumors and the laboratory-grown mini tumors were 96 percent identical across 151 cancer-related genes. There were very few new mutations after culture in a dish. This is crucial, as new mutations can change the tumor's response to medication, the authors explain.

Mini-tumors developed in mice just like their original

Mini-tumors grown in dishes, however, could not be used to test treatments targeting the area surrounding 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 developed over time like the patient's cancer, the researchers report.

Cancer treatments are a race against time

As soon as cancer has spread through the body and no longer responds to standard treatments, a race against time begins to find a drug for patients that can slow the progression of cancer and extend their lives, the doctors say. The reconstruction of the tumors of patients in the laboratory with this new technique is an extremely promising way to predict whether a drug is suitable for a patient. In this way, it was possible to investigate in detail how these tumors reacted to medication, including the patterns of gene activity and the gene mutation. It was even possible to check how the cancer would develop in response to the treatment, the researchers explain.

More clinical trials 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 the experts emphasize that it has the potential to contribute to a truly personalized treatment. Cancer is very complex and is constantly adapting and developing. Therefore, it is extremely difficult for doctors to predict whether a particular drug will work in individual patients. However, the results of the study show that drugs could be tested on replica tumors before the drugs were given to patients. With the help of these mini-tumors, it could even be predicted exactly how a patient will react. (as)

Author and source information

Video: The Answer to Cancer Lies in the Past. Lincoln Nadauld. TEDxBYU (August 2020).