Beyonce and her sister Solange Knowles were tested for the mutated BRCA2 gene after their father Mathew Knowles informed them he had been diagnosed with breast cancer.
The former Destiny's Child manager has publicly revealed he is battling the illness and in an interview on 'Good Morning America' he told presenter Michael Strahan that the first call he made after getting the life changing news was to his musician daughters to warn them that they could be carriers of the same gene which causes cancer.
He said: "The first call was to my family, because this is genetics - it means that my kids have a higher chance, a higher risk, even my grandkids have a higher risk, and they handled it like they should - they went and got the test.
Mathew - who decided to share his condition to mark the start of Breast Cancer Awareness month, which runs throughout October - did not reveal the results Beyonce and Solange's tests.
The music executive - who has Beyonce and Solange with his ex-wife Tina and two young children with current spouse Gena Avery, whom he married in 2013 - admits there has been a history of breast cancer throughout his family.
He said: "Breast cancer has been prevalent in my family. My mother's sister died of breast cancer, my mother's sister's two and only daughters died of breast cancer and my sister-in-law died in March of breast cancer with three kids - a nine, 11- and a 15 year old - and my mother-in-law had breast cancer. So breast cancer has been all around me. My wife's mother has breast cancer, too."
Mathew had his affected breast removed in July and he is currently in recovery and he will be having his second breast removed in January to minimise the risk of getting another tumour.
As a carrier of the BRCA2 gene, Mathew also has a higher risk of developing other forms of cancer and he is being actively tested for them.
He shared: "Now what does having a mutation on BRCA2 mean for a man? You have a higher risk of getting breast cancer, prostate cancer, pancreatic cancer or melanoma ... I'm still getting test results back. I got an MRI for pancreatic cancer and my pancreas and liver are fine. My dermatologist removed 2 moles - both of which came back benign for melanoma. I got an MRI on my prostate a week ago, but we're still waiting on the results.
"I am going to get the second breast removed in January, because I want to do anything I can to reduce the risk. We use the words 'cancer-free', but medically there's no such thing as 'cancer-free'. There's always a risk. My risk of a recurrence of breast cancer is less than five per cent, and the removal of the other breast reduces it down to about two per cent.
"My kids have a 50 per cent [chance of inheriting the BRCA gene mutation.] That's male or female. We used to think this was only an issue for women, but this is male or female."
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