Gene inheritance patterns influence age of diagnosis in BRCA families

December 12, 2011

Women who inherit the cancer genes BRCA1 or BRCA2 from their paternal lineage may get a diagnosis a decade earlier than those women who carry the cancer genes from their mother and her ancestors, according to a new study by researchers at the North Shore-LIJ Health System's Monter Cancer Center in Lake Success, NY. The findings were reported on Thursday, Dec. 8, at the San Antonio Breast Cancer Symposium.

Iuliana Shapira, MD, North director of , and her colleagues conducted a retrospective review of 130 breast or ovarian with the BRCA1 or BRCA2 mutations. They chose only those patients who knew the parent of origin. In other words, they could follow along their family tree to see where the originated from. Some of their families had their own genetic tests done. For others, it was a matter of following the family pedigree.

As expected, a person had a 50-50 chance of getting a mutant from their mother or their father's branch that carried the mutation. It is an autosomal dominant mutation. Looking at the family maps revealed some surprising findings. Contrary to the notion that the BRCA mutations are associated more commonly with Ashkenazi Jews, the scientists found that the BRCA mutations were also in families of Irish and Jamaican descent. "No one had ever conducted a study to look at the parent-of-origin effects," said Dr. Shapira. "Genetic diseases may display parent-of-origin effects. In such cases, the risk depends on the specific parent or origin allele. Cancer penetrance in mutations carriers may be determined by the parent origin of BRCA mutation."

They analyzed 1,889 consecutive (136 ovarian + 1753 breast) breast (BrCa) or ovarian cancer (OvCa) patients presenting for treatment at the Monter Cancer Center between 2007 and 2010. In 130 patients with BRCA 1 or 2 mutations the parent of origin for the mutation was known. Of the 130 patients, two had both BRCA1 and BRCA2 mutated paternally inherited disease and were excluded from this analysis. Of the breast cancer patients: 28 patients had paternal and 29 had maternal BRCA1 mutations, 24 had paternal and 21 had maternal BRCA 2 mutations. Of the ovarian cancer patients, six had paternal and 10 had maternal BRCA1 mutations; seven had paternal and three had maternal BRCA2 mutations.

In carriers of BRCA mutations, the mean age at diagnosis for ovarian cancer was 51 (range 21-70) and for breast cancer was 43 (range 24-78). But when they compared the mean age at diagnosis in the maternal versus paternal inheritance, they were surprised to find that breast cancer patients with a BRCA1 maternal inheritance, the age of diagnosis was on average around 45. By comparison, women with BRCA1 paternal inheritance were diagnosed around 38. For BRCA2 maternal inheritance, the average age of diagnosis was 50 compared to 41 years old for those with a BRCA2 paternal inheritance.

There was no significant difference between paternal and maternal age of diagnosis of BRCA1 or .

"If this observation is duplicated in larger cohorts the results will have important implications for recommendation of surgical risk reduction in BRCA mutation carriers," said Dr. Shapira. "That would mean that doctors might think about watching and waiting in young woman with inherited from her mother's family and being more aggressive in young women who inherited the mutation from their father's side."

Explore further: BRCA2 genetic mutation associated with improved survival, chemotherapy response in ovarian cancer

Related Stories

BRCA2 genetic mutation associated with improved survival, chemotherapy response in ovarian cancer

October 11, 2011
Among women with a certain type of high-grade ovarian cancer, having BRCA2 genetic mutations, but not BRCA1, was associated with improved overall survival and improved response to chemotherapy, compared to women with BRCA ...

Olaparib shows promise in treating ovarian cancer, even without BRCA mutations

August 21, 2011
The PARP inhibitor, olaparib, that has shown promise in women with an inherited mutation in their BRCA1 or BRCA2 gene (accounting for about 5-10% of breast and ovarian cancer cases), has, for the first time, been shown to ...

Risk for developing new cancer in other breast increased for survivors with BRCA mutation

December 8, 2011
Breast cancer survivors who carry the BRCA1 or BRCA2 genetic mutation are at high risk for developing contralateral breast cancer — a new primary tumor in the other breast — and certain women within this group of ...

Recommended for you

'Labyrinth' chip could help monitor aggressive cancer stem cells

September 21, 2017
Inspired by the Labyrinth of Greek mythology, a new chip etched with fluid channels sends blood samples through a hydrodynamic maze to separate out rare circulating cancer cells into a relatively clean stream for analysis. ...

Whole food diet may help prevent colon cancer, other chronic conditions

September 21, 2017
A diet that includes plenty of colorful vegetables and fruits may contain compounds that can stop colon cancer and inflammatory bowel diseases in pigs, according to an international team of researchers. Understanding how ...

New kinase detection method helps identify targets for developing cancer drugs

September 21, 2017
Purdue University researchers have developed a high-throughput method for matching kinases to the proteins they phosphorylate, speeding the ability to identify multiple potential cancer drug targets.

Drug combination may improve impact of immunotherapy in head and neck cancer

September 21, 2017
Checkpoint inhibitor-based immunotherapy has been shown to be very effective in recurrent and metastatic head and neck cancer but only in a minority of patients. University of California San Diego School of Medicine researchers ...

Poliovirus therapy induces immune responses against cancer

September 20, 2017
An investigational therapy using modified poliovirus to attack cancer tumors appears to unleash the body's own capacity to fight malignancies by activating an inflammation process that counter's the ability of cancer cells ...

Brain cancer growth halted by absence of protein, study finds

September 20, 2017
The growth of certain aggressive brain tumors can be halted by cutting off their access to a signaling molecule produced by the brain's nerve cells, according to a new study by researchers at the Stanford University School ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.