Radiotherapy and drugs are effective in pancreatic tumor – 12/11/2023 – Health

The combination of radiotherapy with drugs that act against pancreatic tumors has a better effectiveness in attacking cancer, as well as a superior overall response to treatment, according to new research.

By combining a class of drugs known as superoxide dismutase with stereotactic body radiosurgery (SBRT), researchers were able to make tumors more sensitive to radiation, which allowed them to attack cancer cells with greater efficacy than conventional therapy (without medication).

The combination of therapies also offered greater cancer-free survival, suggests a phase 1b/2 clinical study led by researchers at the MD Anderson Cancer Center and the University of Texas Moffitt Cancer Center in the United States.

The research results were published in the specialized journal The Lancet Oncology last month. In the clinical trial, patients with pancreatic cancer who were 18 years of age or older, who had already undergone a cycle of at least three months of chemotherapy and who were not eligible for surgery for pancreatic cancer were included.

The research was conducted by oncologist Cullen Taniguchi, associate professor at the MD Anderson Cancer Center and who passed away fifteen days before the study was published. The other authors of the study dedicated the edition of the specialized journal to the researcher, a long-time specialist in malignant abdominal tumors.

“Currently, surgery is the only possible cure for pancreatic tumor, but only 10% to 15% of patients are eligible. There are a large number of patients, around 30% to 40%, with an advanced tumor who cannot be surgically removed,” said Taniguchi. “For these patients, we use radiotherapy, but we have known for some time that conventional doses have not been sufficient to eliminate the disease.”

With this in mind, Taniguchi and his team tested the combination of localized drugs with conventional radiotherapy on 47 patients treated at the medical center. Participants were randomized into a group that received treatment with avasopasem manganese, the name of the drug’s chemical compound, and another that received a harmless substance (placebo).

In the treated group, radiotherapy had a better result in attacking the tumor locally, achieving an outcome similar to that of attack with surgery. Regarding the so-called overall response rate (ORR), it was 88% in patients treated with the drug, compared to 67% in those controlled by placebo.

The patients’ disease-free survival rate was 12.4 months, a figure higher than that found when radiotherapy alone was used as a form of pancreatic tumor treatment. In the placebo-controlled group, this rate was just 3.4 months.

The drug’s mechanism of action would be to reduce hydrogen peroxide in cells, a compound that is harmful to the body and remains in high concentration due to the failure of cancer cells to synthesize the compound. Drugs called superoxide dismutase mimetics, such as avasopasem manganese, help healthy cells “clean up” the hydrogen peroxide present in the body, while letting cancer cells be “suffocated” by the excess substance.

According to the researchers, the combination of radiotherapy with this drug offered a more effective fight against tumor cells, preserving healthy cells. “In the trial, patients received some very high doses of radiation, and the drug still helped to shrink the tumor, with expected but manageable side effects,” said the lead researcher. Among the side effects recorded, the most common were abdominal pain, fever, increased lactic acid in the body (causing cramps) and increased secretion of lipase (enzymes that synthesize fat molecules).

The frequency of side effects was similar in the treated (83%) and placebo (88%) groups. According to the authors, a phase 2 clinical trial with more participants is already underway to evaluate the effectiveness of the treatment in more people with pancreatic cancer.