It's a classic that can be distorted. And in addition, it is discriminatory: "a tumor in the lung? Surely everything was smoked …". Who did not listen to phrases like this? It turns out that 25% of lung cancers (yes, in a plural, because they are not all the same) suffer from non-smokers. And in this group that did not even touch the tobacco, it represents the seventh cause of death.
"People who use wood-burning combustion, a common thing in countries like ours, diagnose certain lung cancers," explained the oncologist Luis Corrales, From the Center for Cancer Research and Management, Costa Rica. They are also caused by radiation, chemical inhalation and hydrocarbon gases, and asbestos (asbestos). "Corrals was one of the academics' trainers for lung cancer journalists, led by He was responsible for presenting the panorama of the disease in the region and the challenges it generates, which are many, because the lung is still the deadliest cancer.
In this hard frame, there are good news to give: the available treatments allow in a good number of cases, depending on what type of cancer it is, more time and better quality of life.
We clarify: smoking is not the only cause, but the main preventable cause; It was clear already in 1950. Oncogenesis is not due both to the tobacco itself, but to the mutations that it causes in the cells (in this case, of the lungs, but it is not the only organ that suffers from the consequences) The combustion at high temperatures and the substances that then emit tobacco, its additives and paper, highlighted Corrals.
"These mutations are capable of causing uncontrolled cell division and tumor development," he stressed. And one of the first regional data that we shared competes for ourselves: among Latinos mortality is greater.
But thanks to molecular biology, he added, we know that what has long been considered an isolated disease related to smoking is much more complex and is caused by different genetic changes.
"We can classify lung cancers in two large groups. In the first there are those of small cells (CPCP), more frequent in men, highly associated with smoking and rapid growth, which represent between 15% and 20% % of cases ".
"For these, for a long time there has been only surgery and chemotherapy. But they have made great advances with immunotherapy, which in our country is under approval by the National Medicines Administration, Food and Medical Technology (ANMAT), highlighted in the seminar Diego Kaen, Head of the Oncology of the School and Clinic Hospital of the National University of La Rioja, which made it possible to understand the technical issues of molecular testing.
"The other 80%, that of non-small cells (CPCNP), is subdivided into adenocarcinoma (85% of cases) and others. Well: 35% of patients with adenocarcinoma are not smokers," goes insist Corrals. And it added that 4% of these tumors develop in under 40 years.
The most difficult is the early diagnosis; In fact, lung cancer is still called a "silent killer," because the symptoms are similar to other respiratory diseases (cough for three weeks or more, chest pain, difficulty breathing; flu-like conditions that take a long time improve, even with antibiotics; bleeding of the nose) and the consultation takes a long time to arrive. That is why it is important, in the face of any suspicion, medical control: hopefully tell us it's just a rebel bronchitis! (See "X-rays …").
If the tumor is detected in time and it is surgically removed without it being disseminated, it can be treated and cured. But they are the minority (only 10%): as reported Kaen, in Argentina the majority of the cases is detected in phase III, when it is not curable.
"But that does not mean that there are no possible answers. Until 2014, when they opened the door to a new paradigm, we only had chemotherapy. Now, taking molecular testes of the tumors allows you to formulate directed therapies to improve the survival of groups of patients with metastatic disease, "he stressed.
What it is about is to go directly to the heart of the tumor, or to help the immune system recognize cancer cells. And so, instead of attacking every cell that reproduces rapidly, even healthy ones, as does "chemo", it can block its growth and its spread, interfering in the # 39; The action of specific molecules, called "molecular targets", that activate them, explained Kaen.
"Understanding and understanding the characteristics of the different tumors before starting treatment allows them to be much more effective," said Corrales, "and although it is not cured, in many cases the disease can be controlled for years (in the decade of 1980 and was not trying) with much less symptoms and good quality of life. "
Knowing the tumor means, first of all, knowing what type of tumor it is, and what are the mutations associated with it. And keep in mind, furthermore, that a tumor may not be homogeneous, on one side, and that it is capable of mutating, on the other side, so it must be controlled during the treatment to know if it follows Being effective (see: "liquid biopsy"). The best is that, in many cases, if a treatment stops working, there are others to try to replace it.
"One of the most frequent mutations is that of EGFR. It is a protein that, from the surface of the cells, helps them grow and divide. When EGFR mutates, the cells grow "In these cases (more frequent in women, young people under 40 and non-smokers) EGFR inhibitors can be administered and block the signal that activates the growth of cells."
"In Argentina, the EGFR mutation is found in between 15% and 20% of the cases of this type of cancer," said Kaen, "and one of the great advantages of # 39; these therapies are that they are pills, which are taken home and making normal life. "
There is another 5% of CPCNPs in which it is detected that the ALK gene has mutated, which causes it to generate a protein that hyperestimulates the growth of malignant cells. Available treatments (also pills) can be used even in place of chemo, greatly improving the quality of life.
The new alternative is immunotherapy. In a normal cellular process, T lymphocytes (a type of white blood cell) identify the tumor cells and eliminate them. Our body does this all the time. But they have learned to make fun of the system.
"Imagine that the tumor cells have a mask that hides them, and the lymphocytes are then relaxed. Treatment blocks the receiver that makes the mask possible & # 39; and returns the visible tumor cell to the immune system, "Corrals explained.
They use substances produced by the body or manufactured in a laboratory, such as monoclonal antibodies, which can work by strengthening the immune system and also stopping or delaying the growth of cancer cells, or preventing them from spreading to other parts of the body. body (See: "Immunotherapy").
> Female perspective | Second cause of death in the world
Although overall the likelihood that a woman develop lung cancer throughout her life is from 1 to 17, the numbers are changing and the illness is increasing in the female population. In Argentina, and according to data from the National Cancer Institute (INC), the prevalence of the disease is still much greater among men (68.45% for them and 31.55% for to women), but the increase in mortality due to this type of cancer in women is particularly worrying. Overall, it is the second most common cause of death among them, especially since they made their smoking habit more frequent. In contrast, women seem to benefit from a more pronounced decrease in the risk of tumor once they have abandoned smoking.
> Immunotherapy | We tell you what they are and how monoclonal antibodies work
They are molecules produced in a laboratory designed to act as substitute antibodies, and are able to restore, improve or imitate the attack of the immune system in cancer cells. They are designed to bind to the antigens that are usually more numerous on the surface of cancer cells than healthy ones. Different antibodies of this type are capable of detecting cancer cells, destroying their membranes, blocking their growth or attacking them. They can also block inhibitors of the immune system and are able to carry the tumor cell to the treatment of radiation and chemotherapy. They are administered intravenously, and the frequency depends on the type of cancer and the medication you are taking.
> X-rays do not arrive | If you can not leave the pucho, at least check to make controls "Unfortunately, a massive screening is not possible to detect the disease in people without symptoms," Diego Kaen acknowledged, "but at least smokers should ask their GP for control." The point is that not all control is useful: "it is shown that radiography does not work. Special low density tomography is needed," he added, adding people with a family history to the population at risk. Smoking cessation diminishes precancerous lesions and reduces risk, but this is still important for years after quitting, so the controls should be the rule even if you no longer smoke.