posted on 06/12/2022 06:00
(credit: ANNE-CHRISTINE POUJOULAT)
After two years in the virtual format, the congress of the North American Association of Clinical Oncology, Asco, brought together more than 40 thousand people in Chicago, bringing important news for the treatment of cancer. According to experts, the event, which ended on the 7th, met expectations and showed that, despite the covid-19 pandemic, it was possible to advance in studies on new treatment strategies. Also noteworthy was the debate on inequality in access to medicines, which worsened during the global health crisis.
From the rarest to the most common tumors, over the course of five days, researchers from around the world presented literally thousands of study results, including the poster sessions. In the opinion of physicians who participated in the event, the research that had the most repercussions in the scientific community was related to colorectal and breast cancer. Some of the articles on these diseases showed important gains in patient survival.
For oncologist Cristiano Resende, from Grupo Oncoclínicas, the “girl in the eye” of the congress was phase 3 of the Destiny study, with patients with metastatic breast cancer. “The study was presented in the plenary, with 100% of the doctors attending. It was cheered, the audience stood for a minute and a half, applauding”, says the doctor, who also took a paper to the congress (Read more on this page). The reason for the commotion was the significant increase in disease-free survival (when the cancer is in remission) and in the overall survival of people who, until then, did not have the option of being treated with a drug that has already proven to be very effective in the treatment. of breast tumors.
It is estimated that half of breast cancer patients could benefit from the discovery. These are people who have the metastatic form of the disease, but who have low expression of a receptor on cancer cells that is targeted by the drug trastuzumab deruxtecan, a combination of a monoclonal antibody and a chemotherapy drug. “A few years ago, this drug changed clinical practice”, observes Resende.
However, the substance is only intended for women who have a large amount of the HER2 receptor on diseased cells. Those whose tests show a negative or dubious expression — now classified as HER2-low — had no indication for this treatment. Now, however, researchers have shown that this population can also be treated with trastuzumab deruxtecan and have a significant gain. The Memorial Sloan Kettering Cancer Center study in New York included 557 volunteers with a HER2-low profile. Of those, 373 received the drug, and the rest were treated with standard chemotherapy.
According to the researchers, compared to the second group, in women who received trastuzumab deruxtecan, the risk of the disease growing and spreading was 49% lower. Mortality during follow-up — 18.4 months — was 36% lower. “Our study shows that the substance may be a new and highly effective target therapy option available for the new classification of patients,” Shanu Modi, lead author of the study, said in a press release.
The drug was approved in Brazil this year for HER2 positive patients. The laboratory has already applied for inclusion of those with a HER2-low profile at the National Health Surveillance Agency (Anvisa). However, as it is a new and very expensive drug — treatment for one person costs US$ 50,000 — it is not offered by the Unified Health System (SUS) and even users of private plans may have difficulty getting it in the first place. country.
An unprecedented event in the history of the congress was the presentation of a study that reported 100% remission of a rare rectal tumor at an advanced stage. People with the so-called dMMR have a molecular change that makes it difficult to respond to standard treatment — chemotherapy and radiation. This anomaly, which happens when the cell makes copies of DNA, is present in approximately 5% to 10% of all rectal tumors, according to the authors of the research. Treated for six months with the immunotherapy dostarlimab administered intravenously every three weeks, all study participants were free of dMMR rectal cancer, which was confirmed in radiological and endoscopic evaluations.
The number of patients involved was small, 14, but enough for the work to be recognized as one of the most important of the congress. “The responses in these early patients were remarkable and exceed what we expected with standard chemotherapy plus radiation,” says gastrointestinal oncologist Hanna K. Sanoff, who was not involved in the research. According to the doctor at the North Carolina Cancer Hospital, in the USA, as these rectal tumors do not respond well to chemotherapy and radiation, many patients need to be operated on. “Unfortunately, surgery can result in notable health consequences, including nerve damage, infertility, and intestinal and sexual dysfunction.”
Dostarlimab is an immunotherapy and should arrive in Brazil in August, with indication for the treatment of endometrial cancer. In the study, which will ultimately be done with 30 patients, all 14 participants had dMMR rectal cancer in more advanced stages 2 and 3. “I would like to point out that the majority of these patients had large and bulky tumors. The standard of care for them would probably require all three treatment modalities: chemotherapy, radiotherapy and surgery,” said Andrea Cercek, head of the section on colorectal cancer from Memorial Sloan Kettering Cancer Center and one of the authors of the article, published simultaneously in The New England Journal of Medicine. In the publication, the data are for 12 people, but the number rose later.
“We’ve treated a total of 14 patients, and all — 100% — had a complete clinical response with dostarlimab alone. No patient required chemotherapy, radiation, or surgery. There was no progression of tumor grade. No recurrences of the disease were observed.” , continued Cercek, noting that a longer follow-up of these people is necessary to establish the durability of the treatment. For now, they have been evaluated over two years.
three questions for
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Fernando Maluf, oncologist and founder of the Vencer o Câncer Institute
Did the covid pandemic interfere in any way with research in the oncology area?
The pandemic has disrupted cancer research and treatment worldwide, and one of the main reasons was isolation. What happened is that the number of patients included in clinical protocols dropped dramatically. Many of them ended up having difficulty accessing the centers. In our country, in several places where the cancer structure was coupled to non-oncological areas, beds were directed to covid; chemotherapy application rooms aimed at other conditions; and crowded ICUs. What happened was that, as a structural issue, many hospitals had a reduction in the care of cancer patients.
There were many expectations regarding Asco 2022, as it was the first in-person congress since 2019. Did the works presented correspond to what was expected?
It was very good to be face-to-face because we can, again, what we can’t do online, which is interacting with colleagues and leaders from all over the world and designing research projects working as a group. The works met expectations. There have been major breast cancer studies such as Destiny that have shown a very significant progression-free survival gain. Another study with 12 rectal tumor patients who had a complete response with immunotherapy alone, without the need for chemo, radio or surgery. In addition, there was important consolidation, such as radiopharmaceuticals, the case of metastatic castration-resistant prostate cancer; the role of immunotherapy, increasing the survival of patients with cervical cancer; new immunotherapeutic drugs in the treatment of superficial bladder cancer; and the introduction of new agents in head and neck cancers, increasing survival with radiotherapy. These are very important studies because they can benefit patients in the short term.
In addition to study results, the congress addressed inequality in access to medicines. How was that debate?
This was the subject of several congressional tables. It’s no use having technology if it doesn’t reach people as a whole. So, I think that even from the point of view of international agencies, there is a greater concern about how we can guarantee equity in the care of cancer patients within their own countries and also between countries around the world.
Increase in cases of metastasis
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The covid pandemic did not only make victims among those infected by Sars-CoV-2. Cancer patients were harmed, which resulted in a reduction in the diagnosis in the initial phase, making the chances of cure difficult. A Brazilian study presented at the poster session of the Congress of the North American Society of Clinical Oncology (ASCO) found an important statistical decrease in attendances, at the same time that the number of patients with metastases increased.
The study was based on data from nearly 12,000 people served by the Oncoclínicas group across the country, including Brasília. The researchers compared the number of breast cancer patients who sought the network’s clinics between 2018/2019 with those who sought medical help between 2020/2021.
“There was a decrease in the number of initial patients (who were consulted for the first time), from 68% to 58%. At the same time, the number of patients with metastatic disease increased, from 12% to 19%”, says the oncologist Cristiano Resende, one of the authors of the research. He explains that, although the study did not investigate a cause and effect relationship, it is very likely that the statistics are explained by the pandemic, when many people stopped leaving their homes to undergo routine tests that can detect the disease at an early stage.
“It is very clear that this is related to the lack of the screening test”, observes Resende. “We’re talking about a disease that, when metastatic, is incurable. There was an increase in patients with metastases of 7%. Exactly in the age group where there were more chances to prevent it, which are women over 50 and post-menopausal. . This is also the group at greatest risk of covid. So, we believe that many people stopped taking the exams due to isolation.”