The Asco (American Society of Clinical Oncology) congress ended last week in Chicago (USA). It is the largest oncology event in the world that is known for presenting the main updates and news about cancer treatment. After two years, in 2022 the meeting was once again in person.
In this edition, the main research has brought important discoveries in approaches that can reduce side effects, in addition to pointing out with greater precision whether or not there is a need for chemotherapy, for example.
The most promising presentation, highlighted by oncologists heard by Live wellrecorded cancer remission in all 12 participating rectal cancer patients, with no evidence of tumor on physical examinations, endoscopy, positron emission tomography (PET scans) and MRI.
The research used for six months doses of the immunotherapic dostarlimab, —a monoclonal antibody—, already released in Brazil, but which will arrive in August to be used against a rare type of cancer in the endometrium (tissue that lines the inner wall of the uterus).
These rectal cancer patients face grueling treatments — chemotherapy, radiation and surgery that can result in bowel, urinary and sexual dysfunction. Some need colostomy bags.
They entered the study thinking that when it was over they would have to undergo these procedures, because no one really expected their tumors to go away. But they were in for a surprise: no further treatment was needed.
The medication was given every three weeks for six months and cost about $11,000 per dose. It unmasks cancer cells, allowing the immune system to identify and destroy them.
In the case of the research in question, patients with colorectal cancer were treated at different periods and are followed up from two years to six months post-treatment, so far without reports of serious adverse events.
Treatment is limited to 5% to 10% of people with rectal cancer, as they must have Lynch syndrome, a genetic condition that predisposes them to the disease. But the new practice is exciting, mainly due to the level of tolerable side effects, and may open the way to new approaches against the disease.
In the present study, the experimental method replaced the standard protocol, which usually combines radiotherapy, chemotherapy and surgery. The intervention is usually very aggressive and the patient needs a colostomy (a process in which the intestine is “externalized” and a bag collects waste from the digestive system).
“Colorectal cancer brings great morbidity, with important long-term sequelae, especially for those who undergo radical surgeries, which compromise the rectal muscle and require colostomy for the rest of their lives”, says oncology surgeon Samuel Aguiar, a member of SBCO ( Brazilian Society of Oncological Surgery).
Chemotherapy: techniques map if it is expendable
New trends are also trying to map the need or not for chemotherapy, focusing on that indicated for adjuvant treatment (used post-surgery as a preventive measure against remaining cancer cells). As much as the treatment is safe and effective, much is questioned about the quality of life of patients due to side effects.
“We managed to stratify and save patients from chemotherapy when some biomarker is not present. With that, we gain tools to provide security and de-escalate treatment in very common cancers”, indicates oncologist Angélica Nogueira Rodrigues, PhD by Inca (National Cancer Institute) and member of the SBOC (Brazilian Society of Clinical Oncology).
One of the main studies mapped the presence of a “hidden” DNA in the blood of patients with type 2 colorectal cancer. The Johns Hopkins Hospital team (USA) analyzed the levels of ctDNA (circulating tumor DNA), the amount of genetic material with small of the tumor circulating in the blood. Those who tested negative would not need additional post-surgery therapy.
After the evaluation, the study did not identify differences that compromised the health of those who did not undergo chemo. Survival and cancer recurrence rates were 92.4% versus 93.5%, with the latter percentage referring to the ctDNA-focused approach. Now, the researchers explained, the expectation is to expand screening to other types of cancers.
Another similar study also evaluated the risk of releasing patients from the age of 70 with breast cancer from chemotherapy, without observing changes in survival for a period of four years. As well as the approach with patients who had small tumors, without axillary involvement, which replaced treatment subsequent to surgery with radiotherapy for hormone therapy. After the intervention, of the 500 women followed up, only 2.3% had a recurrence of the disease within five years.
Breast cancer progression
Regarding rare breast cancer, a medication called trastuzumab deruxtecan was indicated as a treatment capable of extending patients’ lives by six months, after decreasing disease progression and tumor size.
The study looked at 557 patients, divided into two groups, with a tumor type classified as HER2-low (previously, they were ruled out for this type of treatment, but the new research indicated they could benefit from the approach), all with metastasis, when the disease has already spread to other organs and/or tissues.
According to the researchers, those who received the medication had their disease averted for 10 months, while the other group saw a decrease for half the period. The observed side effects were within the standards, treated with symptom-focused drugs.
New in prostate treatment
A proposal for a new protocol for the treatment of metastatic prostate cancer was also presented during the Asco congress. Generally, approaches to advanced tumors use a type of hormone therapy in an attempt to stop the progression of the disease.
This time, the research used a set of three medications, including darolutamide, as a combination to have direct action against cancer cells.
“We realized that, in addition to preventing the production of testosterone, blocking its action on the tumor cell would make the patient respond better and live longer”, says oncologist Diego Rosa, from Grupo Oncoclínicas (RJ), who was part of the team survey with Brazilian participants. According to the study, the drug reduced the risk of death by 32.5%.
For the use of the protocol in Brazil, the medication must be approved for this specific purpose by Anvisa. “We hope that it enters the ANS list because the operators will have to give it to the patient when there is an indication”, considers Rosa.
Promising treatment for rare cancer
Also presented were the primary results of the SHINE phase 3 study, performed in patients aged 65 years and older with mantle cell lymphoma (MCL) newly diagnosed. Research has shown that the combination of oral ibrutinib once daily plus bendamustine-rituximab (BR) and rituximab maintenance significantly reduced the risk of disease progression or death by 25% compared with patients receiving placebo plus BR and rituximab maintenance.
Mantle cell lymphoma, rare, occurs in B cells and is within the group of non-Hodgkin’s lymphoma (NHL). This cancer can present with different characteristics, including being able to evolve more quickly (aggressive) or more slowly (indolent). Precisely because of this diversity, symptoms can manifest in different ways and treatment is adapted to each specific case.
Although there is a wide range of options for therapy, in most cases, this neoplasm is not curable. Therefore, the main objective is to increase patient survival with quality.
This study is one of the largest clinical trials ever performed on first-line MCL and the first for a Bruton tyrosine kinase inhibitor (BTKi) — an enzyme important for the development and differentiation of B lymphocytes.
It usually affects people over age 65, who typically cannot tolerate intensive chemoimmunotherapy and stem cell transplantation, resulting in poor clinical outcomes and contributing to the need to develop additional treatment options for these patients.
“There is an urgent need to improve outcomes for older patients with MCL,” said Michael L. Wang, professor in the Department of Lymphoma and Myeloma at the MD Anderson Cancer Center, from the University of Texas (USA), and principal investigator of the study. “Given the median progression-free survival of 6.7 years, the ibrutinib combination demonstrated the potential to be a first-line treatment in this population.”
The study recruited 523 patients aged 65 years and older. All participants were randomly assigned to receive ibrutinib or placebo plus BR for a maximum of six 28-day cycles; participants with complete or partial responses continued to receive maintenance therapy with rituximab every second cycle for a maximum of 12 additional doses.