In 2008, Mercè was barely two years old. She had been sleeping badly for a long time, she had lactose intolerance. One day her mother, Marta, took her to the pediatrician, who noticed that she had a mass in her abdomen. A subsequent ultrasound revealed that the girl was suffering from a Wilms tumor, a type of kidney cancer. “But it just so happened that we had already had another case of childhood cancer. And that my mother-in-law also had cancer as an adult,” says the mother.
Mercè was treated at the Vall d’Hebron Hospital (Barcelona). She had a kidney removed and now she is a healthy 17-year-old student. But in 2017 the center created the pediatric oncogenetics consultation, pioneer in Spain, who performed tests on the child and found that the child’s tumor contained a genetic component, although not hereditary. In other words, his case had more to do with a genetic alteration produced in the embryonic development than with an ‘inheritance’ from some relative.
“My mother-in-law also had that detected. genetic component. And that helped us to orient the diagnosis for adults, to to make prevention. For example, my sister-in-law and my husband had colonoscopies every year until recently, because they ended up seeing that they aren’t as much of a risk as their mother.” explains Marta. Tomorrow, Wednesday, February 15, is the celebration of the International Childhood Cancer Day.
Every year in Catalonia, some 10% are diagnosed as hereditary. 250 new cases of cancer in children and adolescents, most of which are sporadic or non-hereditary. Despite this, about 10% of pediatric patients with cancer do have some degree of predisposition to it. These are hereditary disorders associated with a increased risk of certain types of cancer, a percentage that grows as knowledge about the genetics of the disease increases.
For this reason, Vall d’Hebron created almost six years ago the pediatric oncogenetics consultation, to optimize the molecular diagnosis and medical follow-up of pediatric patients with a genetic predisposition to cancer. Since 2017, the practice has prescribed a genetic study of 90 of 156 pediatric patients. assessed after studying their family tree. 46 patients, more than 50%, presented hereditary predisposition to cancer.
“Genetics has come a long way in recent years. In this practice we see children who already have cancer and who we think it is because of a genetic cause, but also to other patients who don’t have cancer but who we think do are at risk of having it. This is how we start follow-up and early detection programs”, he explained this Tuesday at a press conference. Lucas Moreno, head of Pediatric Oncology and Hematology at Vall d’Hebron.
The family tree
This pediatric oncogenetics consultancy collects information from. three to four generations of the family tree of the patient, to detect if there are any family history That explains the child’s diagnosis. “But a lot of times that doesn’t give us information to determine the cause. We don’t see all cancer patients, but those who suffer tumors early, who have a history or with certain dysmorphological or anthropometric features,” explained Estela Carrasco, genetic counselor of the Medical Oncology department. For example, aspects such as the distance between the eyes, the implantation of the ears, the characteristics of the palm lines or the existence of macrocephaly may point to a “specific syndromic entity,” he said. Anna Maria Cueto-Gonzalez, pediatrician specialized in clinical genetics.
In the case of patient Mercè, the doctors at Vall d’Hebron saw that, although her family history “had cancer”, those cases had nothing to do with hers. “Analyzing family history helps us to see if there is an association between tumors.” Carrasco said. She explains that a genetic alteration does not have to be hereditary. “All tumors are genetic, but not all are hereditary. In Mercè’s case it was not hereditary, we saw it in the test. There are genetic alterations that occur during the embryonic development, but you can only know that by analyzing the tumor,” the doctor added.
Thus, in Mercè’s case, as the cause was ruled out as hereditary, it was seen that. the “risk” was in her, so the young woman (who assures us that this whole process has awakened her interest in genetics, something she plans to study) is doing the follow-ups she needs to do. “The rest of her family does not have the risk that she had. Once you detect that someone is a carrier of this genetic alteration, you look at the rest of your family members. Seeing that you don’t have this risk gets you out of that follow-up, out of that risk group,” said Carrasco.