The genetics of tumors has the key to knitting
as the personalized treatment for each patient. So far, in breast cancer, they
were almost always and clinical criteria (pathologic analysis of tumor)
biological (patient age, grade, and stage of the disease) which defined the
risk of recurrence (recurrence) and decided convenience give a woman newly
chemotherapy underwent surgery for breast cancer. The genetic study of
neoplasms reserved for very specific cases where the biological results raised
doubts to physicians when making the decision. However, the international study
MINDACT, presented on Monday its first results of the American Association for
Cancer Research, has certified the efficiency of genetic studies to decide
whether to give chemotherapy or not to many patients. The investigation
revealed that the genetic MammaPrint test is able to detect some tumors
considered at high risk of recurrence according to traditional criteria, in
fact, they are not, so it would not be necessary to supplement surgery with
chemotherapy. Thus, the MammaPrint could reduce up to 14% cases that the
chemical treatment is administered.
Genetic tests are not new in breast cancer. In
fact, they have also studied their bonanzas to predicting the outcome of
treatment. But what evidence this study is the effectiveness of the test to
detect the risk of recurrence of tumors and their ability to avoid unnecessary
chemotherapies. The Dr. Isabel Rubio explains: "We tried to compare the
pathology of the tumor with the study of their genes to see which gave us more
information about the tumor and how much you could save on chemotherapy. We
analyzed tumor aggressiveness and risk of recurrence of the patient," head
of the Breast Unit at Vall d'Hebron Hospital and spokesman for the cooperative
group Solti, a medical group that coordinated the study in Spain. According to
the latest report of the Spanish Society of Medical Oncology (SEOM), breast
cancer is the fourth most tumor incidence in Spain and the first women (25,215
new cases in 2012).
In the study, which involved 11 European
hospitals (nine of them Spanish), 6,693 women who had undergone surgery for
breast cancer they were recruited. The researchers assessed the risk of
recurrence of the tumor from the two systems: on the one hand, the MammaPrint,
which analyzes 70 genes of the tumor and on the other hand, the tool Adjuvant!
Online, which calculates at risk of recurrence based on common clinical and
biological criteria. The two evaluation systems agreed to catalog 2,745 women
at low risk of recidivism and other 1,806 high risks. But dissension between
the two tools emerged with 592 patients considered low risk according to the
parameters of the Adjuvant! Online high recidivism for MammaPrint, and other
1,550 low risks for genetic and high test according to traditional criteria.
Of the 3,356 women who were classified
according to traditional parameters such as patients at high risk of
recurrence, treatment according to MammaPrint prescribing chemotherapy reduced
by 46%. In the group of patients that the genetic test considered low risk and
the traditional criteria of the high risk of recurrence, the study showed that
the five-year survival without metastases exceeds 94%, regardless of whether
they had received chemotherapy or not. "This research gives light to
change clinical practice because it is a randomized study of high scientific
evidence that the test can prevent many women undergo chemotherapy and its side
effects and the result is just as good," says Rubio. Research the coming
weeks will be published in a scientific journal.
Experts warn that does not work for all
patients
Experts consulted agree that this study shows
the effectiveness of a mechanism they already proved in clinical practice.
"So far the genetic test we used it in very specific cases when we had
serious doubts as to make decisions about treatment. But this is the future
because it allows us to better classify patients and see which treatment is
more convenient," said Dr. Maria Eulalia Fernandez, a specialist in
gynecologic oncology and member of the Catalan Society of Obstetrics and
Gynecology, Academy of Medical Sciences of Catalonia. Dr. Cesar Rodriguez,
spokesman for the Spanish Society of Medical Oncology (SEOM) ensures the
effectiveness of this method "may deliver chemotherapy patients and all
adverse effects" but points out that the niche you are targeting is
limited to women intermediate risk. "It is for all patients because there
are cases that only the results of the pathology are clear that they are at
very high risk or low," the oncologist practicing in the Clinical Hospital
Universitario de Salamanca. "This study reaffirms us something we already
had quite clear. There were retrospective studies that claimed but prospective
investigations needed to reaffirm what we do and in clinical practice is
well," concludes Rodriguez.
But the MINDACT does not end here. This is just
one of the legs of the larger project of research managed by the European
Organization for Research and Treatment of Cancer (EORTC in its acronym in
English). "This study also impact the surgery because surgical treatments
can analyze there so far and move towards more individualized treatment
according to each case," Rubio advances. The MINDACT has a large biobank
which will also study new biomarkers of disease. "The molecular study and
gene profiles of the tumor are the future," concludes the researcher.