Breast Cancer Prognosis


Breast Cancer Prognosis using your 23andme BRCA1 raw data

Breast cancer prognosis is good when the cancer is detected earlier than when it is detected during the later stages of the disease. According to WHO, Breast Cancer is the most common malignancy among women, both in the developed as well as in the developing nations. Though this type of cancer is known to have a good prognosis, there are variations in survival, which is indicative of a genetic basis.

There have been considerable strides in developing candidate gene testing for breast cancer over the past 10 years with variants primarily identified in breast cancer susceptibility genes, microenvironment of the tumour and in genes associated with drug metabolism. Genome wide association studies have permitted the identification of gene variants that are located in genes which have never been associated with cancer susceptibility. The common breast cancer variant markers, commonly SNPs are found in the new v5 23andme chip. Hence it is possible to use your 23andme BRCA1 raw data to learn more about  breast cancer prognosis.

Genetic Testing for Breast Cancer Prognosis:

A study conducted on a Swedish family with affected first degree family showed a higher risk of mortality, indicative of a genetic basis. Women with breast cancer are found to have 60 to 80% higher risk of mortality when they have first degree relatives with poor prognosis than if they have relatives with good prognosis. The association with prognosis was more definitive when the cancer was detected at a young age. If you have already done an ancestry genetic report for your family all you have to do is upload the your raw data onto our tool to learn more about breast cancer prognosis. 

The host genetic makeup, apart from familial inheritance, plays an important role in the molecular profiling of the cancer subtype. Such differences could lead to altered molecular behaviour, affecting the prognosis of the patient.

Genetic susceptibility to certain cancers

In the Swedish study, there existed a smaller gap in the age at which the cancer was detected between sisters when compared with the age of diagnosis of breast cancer in the mother, suggestive of a larger genetic aspect in determining prognosis.

There is increasing evidence from research studies that specific gene variants are associated with specific types of cancer, which is, in turn, influence the survival of the individual. For example, BRCA1 is associated with early onset breast cancer, which is also associated with poor prognosis.

The gene variants carried by an individual could influence

  • The type of tumor
  • Response to the therapy for the cancer
  • Host response to the cancer

This can be identified using your 23andme BRCA1 raw data.

Role of genetic variant implicated in breast cancer prognosis

One of the genetic variants associated with prognosis has been shown to regulate the expression of SNCG (Synuclein gamma) gene. Studies have shown that an increased expression of synuclein gamma is associated with an increase in the motility of cancer cells, contributing to their survival. This gene has also been implicated in late stage metastasis in breast and ovarian cancer.

Another genetic variant associated with prognosis is present near a gene which codes for a specific proteasome component. There is an increase in proteasome activity among tumor cells, associated with an increase in cell growth.

The biological associations of these genetic variants along with their association with prognosis in population studies, make them candidate genes for prognosis analysis.

Identifying the genetic variants that you carry will help in developing treatment strategies to improve prognosis. One study showed that hormone replacement therapy was associated with prognosis, while another study found that the number of pregnancies and the age at pregnancy was also associated with prognosis. Response to chemotherapy is also associated with genetic variants carried and this information can also be used to for a personalized treatment plan.

You can now find out if you carry the variants associated with breast cancer prognosis from Xcode’s Breast Cancer report by uploading your 23andme BRCA1 raw data or any other ancestry DNA raw data. You can read more about the Xcode Breast Cancer report here.

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