4 novelties that could revolutionize cancer treatment – BBC News Africa

The drug trastuzumab has been used to treat breast cancer for decades.

Despite the good results, however, it always had a limit: it could only be prescribed to patients with tumors that were highly expressing a gene called HER2, which research confirmed.

But that has now changed: One of the big news at the congress was the results of the study on the active substance trastuzumab-deruxtecan.

“We are witnessing the arrival of a revolutionary medicine,” says oncologist Romualdo Barroso, research coordinator at Sírio Libanês Hospital in Brasilia.

“After many years without much news, we have a new treatment option that increases survival (longer life) for patients.”

According to Barroso, the new drug acts like a Trojan horse (meaning it looks like one thing but acts like another).

Trastuzumab is a monoclonal antibody, a type of drug that can be used to both prevent and treat disease. In breast cancer, it binds to receptors on the surface of cancer cells.

This has two main effects. The first is to get the “attention” of the immune system, which begins to see the cancer as a threat and initiates a series of actions to fight it.

The second is to allow deruxtecan (the second part of the drug) to “penetrate” diseased cells. It is a powerful chemotherapy drug that destroys the tumor from the inside.

But the novelty goes beyond the mode of action: the new drug also works well in patients with tumors that express fewer HER2 genes.

In practice, this means that more people can benefit from this remedy. Almost seven out of ten patients, Barroso estimates.

The drug, which is given into a vein every 21 days, is still awaiting approval from regulators for use in hospitals.

First, it can be used as a second line of treatment, that is, when the first options have failed and the disease has spread to other parts of the body (a process called metastasis).

According to Barroso, it is likely that over time this will also be an option for early-stage tumors.

Imagine a drug that manages to make a disease go away in all patients in the study that was conducted to analyze whether it works or not.

Of course, such a positive result attracts the attention of non-professionals.

“But even for us doctors, it’s very surprising,” says oncologist Rachel Riechelmann, head of the Division of Clinical Oncology at the AC Camargo Cancer Center in São Paulo.

This is exactly what happened in a study of dostarlimab to treat cancer of the rectum (the last part of the intestine). It is already used for other tumours, such as tumors of the womb lining (tissue that covers the womb).

Dostarlimab belongs to the class of immunotherapies that stimulate the immune system to attack the tumor.

The study involved 12 patients who were followed for six months. In the end, none of them had any indication of a tumor in their body.

This saved her from having to switch to more aggressive treatments such as surgery, radiation therapy or chemotherapy.

Although the result is impressive, some considerations should be made.

The first has to do with tracking time. “The six-month evaluation is a short period. It is possible that the disease will reappear a few years later,” analyzes Riechelmann.

Second, dostarlimab only works in a limited group of patients with tumors with a property called “microsatellite instability”. It is estimated that approximately 1% of rectal cancer cases meet this criterion.

Although the drug is not approved for the new use, research is even continuing to find out how long patients actually live without this tumor.

“But the initial results were so good that it no longer makes sense to compare this immunotherapy with earlier methods such as chemotherapy and radiation therapy,” says Riechelmann.

“It’s a treatment that has been shown to be better and less toxic,” he concludes.

In general, international oncology congresses bring advances in new tools, diagnostic methods and, of course, medicines.

This year, however, work on colorectal cancer (which affects parts of the colon) was proposed because it took exactly the opposite approach: reducing the number of procedures the patient has to undergo.

A group of researchers from Australian institutions have evaluated a test that detects parts of tumor DNA that appear in the bloodstream. The procedure is known as a “liquid biopsy.”

But what does this have to do with colon cancer? Patients diagnosed with this condition usually have surgery to remove the affected part of the intestine.

However, after healing, the doctor always wonders if there is even a microscopic part of the tumor left in the patient’s body. If it persists, the disease can grow back and even spread throughout the body.

Just in case, many people undergo chemotherapy after surgery to remove troublesome tumor cells.

This reduces the risk of recurrence, but exposes patients to heavy therapy that can have side effects.

This is where the new test comes in: By detecting the pieces of tumor DNA, it is determined who really needs the second round of treatment.

“If the result of the liquid biopsy is positive, he goes to chemotherapy. If he’s negative, he doesn’t need them,” summarizes oncologist Rodrigo Dienstmann, medical director of Oncoclínicas Precision Medicine, in São Paulo.

In the study validating the technique, 455 volunteers were divided into two groups. The first 302 had the liquid biopsy right after the surgery. For the remaining 153, the doctor decided whether or not to do chemotherapy.

“Of those who had a liquid biopsy, 15 percent went on to chemo afterwards. Among the other 28 percent,” said Dienstmann.

“That means it was possible to reduce the use of chemotherapy by half and achieve the same result in terms of patient survival,” he compares.

“Liquid biopsy has revolutionary potential,” analyzes the doctor.

Pancreatic adenocarcinoma may top the list of tumors with the worst prognosis.

“This cancer has a very high mortality rate. Approximately 90% of patients do not survive for five years, even when diagnosed early,” explains Dr. Paulo Hoff, President of Oncologia D’Or.

In the last ten years, the development of the treatment of this disease has been limited to the introduction of new chemotherapies – the progress related to more modern and less aggressive drugs, such as immunotherapy and monoclonal antibodies, has not helped in this case this disease affecting the pancreas.

But a new possibility has opened up: At this year’s American Oncology Congress, the first tests using a method called CAR-T cells against this type of cancer were presented.

The therapeutic tool, already approved for certain blood tumors (such as lymphoma, leukemia and multiple myeloma), consists of harvesting a patient’s own immune cells, modifying them in the laboratory and then reintroducing them into the body to recognize and fight the tumor.

According to the presentation at the congress, CAR-T cells were tested in a pancreatic cancer patient in the United States. The first results were positive.

“Although the use of this therapy against pancreatic adenocarcinoma is extremely interesting, tomorrow it will not be available in our clinics,” reflects Hoff, Professor of Clinical Oncology at the University of São Paulo.

“There’s still a long way to go, but at least now we have hope that we can be on the right track.”