Genetic testing creates opportunities for treatment, but also confusion among breast cancer patients

The last decade has witnessed a rapid expansion of genetic tests, which include new instruments to inform patients, who have been diagnosed with breast cancer, about the success of breast cancer.

But the clinical relevance of many of the hereditary mutations that can now be identified remains unclear, and the experts do not agree on when and how to deploy the new tests available. A veces, los pacientes tienen que pagar de su bolsillo por ámenes que todava son el estándar de atención, e even los oncólogos más actualizaciones pueden no estar seguros de cómo incorporar la avalancha de loosolínto de loosolínto de loosoformeco .

Hace un quarto de siglo, Myriad Genetics introduced the first breast cancer genetic test for BRCA mutations, two genes associated with an increased risk of breast cancer, opening the door to a new test.

Mutations in the genes BRCA1 and BRCA2 are responsible for up to half of hereditary breast cancers, and people with a problematic mutation in one of these genes have between 45% and 72% of the maabilidades of masarolández along their length. vida. También pueden tener UN Mayor riesgo de padecer cáncer de ovario, y otros tipos de cáncer, que las personas sin câncias dañinas en el BRCA.

But the clinical significance is less clear for many other genetic tests.

Las pruebas de los genes BRCA1 y BRCA2 used to cost thousands of dollars. Ahora, por una fraction de ese price, los medicos pueden pedir a los laboratorios comerciales panelse de pruebas multigénicas que buscan mutations en dozenas de genes. Algunas empresas de venta directa al consudorum ofren paneles de detección por unos pocos cientos de dolares, aunque su reliability varies.

When Jen Carbary was diagnosed with breast cancer in 2017 at the age of 44, genetic tests identified a mutation in a gene called PALB2 that significantly increases the risk of developing cancer. The guidelines suggest that patients with breast cancer with a PALB2 mutation, as well as those with BRCA1 and BRCA2 mutations, should consider undergoing a mastectomy to reduce the possibility of recurrence.

“I wish the genetic tests were the standard of medical attention,” said Carbary, who said nothing was needed for the test because his insurance company covered it.

Carbary, who lives in Sterling Heights (Michigan), said that the results of the tests reaffirmed her decision to undergo a double mastectomy and provided important information to members of her family, including her 18-year-old son. They will probably be tested in the middle of their 20s or at the beginning of their 30s.

But some experts in breast cancer are concerned that the generalization of the tests can also identify genetic mutations whose impact is not clear, which would create anxiety and lead to more cost-effective treatments and sanitation.

También puede confundir al paciente.

“Ocurr a menudo que las pacientes acuden a nosotros después de obtener resultados confusos en otros lugares,” indicated Dr. Mark Robson, chief of the breast medicine service at Memorial Sloan Kettering Cancer Center in New York. Robson explained that the oncology center has a clinical genetics service, formed by doctors and genetic counselors, that help people make decisions about how to manage the results of this type of testing.

For people diagnosed with breast cancer, many professional groups, including the influential National Comprehensive Cancer Network (NCCN), recommend limiting testing to certain people, including those who have high-risk factors, such as las que tienen 45 años o menos cuando son diagnosadas; y las que tienen ascendencia judía asquenazí.

But in 2019, the American Society of Breast Surgeons (ASBrS) recommended a different approach: Offer genetic tests to all patients who have been diagnosed or have a personal history of breast cancer. The recommendation was controversial.

“Las direcrices de la NCCN cover a la majoria de las mujeres que necessitan pruebas, pero nosotros queríamos hacerlas a todas”, said Dr. Eric Manahan, surgeon general in Dalton, Georgia, and member of the SBrtiva de la junta directive.

Mutations in other genes associated with breast cancer are much less common than mutations in BRCA1 and BRCA2 and, in general, do not increase the risk of developing breast cancer. The impact of these genes on cancer can be less clear than that of the BRCA genes, whose detection has been carried out since the mid-nineties.

Y la respuesta adequada a las mutations menos comunes—that is, a mastectomy to reduce risk or intensive screening—a menudo no está clara.

“Las cosas se vuelven increasingly más más confusas cuando se examinan otros genes”, affirmed el doctor Steven Katz, profesor de medicina y politicas sanitarias de la Universidad de Michigan. “Los riesgos tenden a ser menores para diferentes tipos de cáncer, y menos seguros y más variables. Puede que llegue a preguntarte: ‘¿Por qué tengo que saber esto?”.

Una vez diagnosado el cáncer de mama, las pruebas genéticas pueden ayudar a tomar decisions sobre el tipo ciguría que se debe realizar; por ejemplo, un alto riesgo de recurrence o un nuevo cáncer de mama puede hacer que algunas peso opten por una ciurgia más extensa, como una doble mastectomía. Tests can also provide important information to family members about their possible risk of cancer.

(This type of genetic testing, called “germline”, examines the mutations in the genes that people inherit from their parents. It is different from the genomic tests of tumors, which examine the germline genes of the genes ayudar a los médicos a entender el ritmo de división de las célús cancerosas, por ejemplo, y la probabilidad de que el cáncer reaparezca).

Increasingly, germline genetic tests can also help guide other treatment decisions. Algunas patients with metastatic breast cancer that present mutations in the BRCA1 or BRCA2 genes can be good candidates for PARP inhibitors, drugs against cancer that attack tumors with mutations and more.

Pero las pruebas genéticas que discovereren mutaciones herdadas en muchos otros genes arrojan una información menos clara, aunque los resultados positivos pueden alarmar a las persons.

At Memorial Sloan Kettering, cancer specialists focus on “therapeutic action capacity,” said Robson. ¿Ayudarán las pruebas a alguien a decidir si debe submiterse a una doble mastectomía o le provicirán otra importante orientation? “Una política de pruebas para todo el mundo will identify muy pocas mutations mamarias BRCA adicionales, pero costará mucho”, he added.

Consequently, doctors debate which is the best way to deploy and incorporate new genetic knowledge. Y las aseguradoras try to find out what they have to pay.

There is a subutilization of evidence that science says are relevant and an overutilization of evidence that, according to experts, provides information that cannot be interpreted with any scientific certainty.

The result can be the confusion of patients who have just been diagnosed with breast cancer, because they face the costs of genetic tests and, in some cases, a lack of orientation about the lack of orientation.

Some doctors affirm that the first step is to ensure that the small group of people who will benefit clearly are subjected to genetic tests whose meaning is clearly understood. Only 15% of patients with breast cancer who complied with NCCN’s select test guidelines for hereditary cancer received genetic tests, according to a 2017 study that examined data from na502017 and na50201.

“Yo diría que nuestro enfoque debe estar en las personas con alto risego de mám cáncer que ni siquiera están identificadas todava”, expresó la doctora Tuya Pal, Director para las disparidades del salud del cáncer en el Centro de Cáncer Váncer de Cancer. del panel de directives de la NCCN para la evaluación genética/familiar de alto riesgo de cáncer de mamma, ovario y pancreas.

Los pacientes pueden caer en el olvido porque nadie les dice que deben hacerse la prueba. In an analysis, 56% of high-risk breast cancer patients who did not undergo genetic testing said that their doctors did not recommend it.

Even if doctors recommend genetic tests, they may lack the necessary experience to determine which tests are needed and how to interpret the results. This is the function of genetic counselors, but there are many available.

Las consequencias pueden ser graves. In a study of 666 patients with breast cancer who underwent genetic tests, half of those who had a medium risk of developing hereditary cancer underwent a double mastectomy because they found “variants inquierto requienqueré, que que que semtieron” Action Clinica Hasta la mitad de los cirujanos informaron de que trataban a estas pacientes del miso modo que a las que tenían mutaciones cancerígenas.

“The bulk of our investigation would say that there is still room for improvement in terms of how doctors get the training they need,” said Dr. Allison Kurian, Director of the Clinical Genetics Program at the Department of Clinical Genetics. . del estudio.

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