According to statistics released by the International Agency for Research on Cancer (IARC) in December 2020 and cited by the World Health Organization (WHO), breast cancer has now surpassed lung cancer as the world's most commonly diagnosed cancer. The subject experts suggested that to a large extent, the disease is hereditary in nature. The experts said that inheritance, either by disease history in family or by genetic changes, augments the probability of developing cancer.
According to them, highly predisposed to developing breast and ovarian cancer are those whose family has a history of breast cancer or found inheriting a separate set of genes. Speaking to IANS on World Cancer Day on Thursday, Pragya Shukla, Head of Department, Clinical Oncology, at the Delhi State Cancer Institute, said that offsprings of a cancer survivor are also more susceptible to developing breast or ovarian cancer.
"A woman is more prone to develop breast or ovarian cancer if either her mother is a cancer survivor or any of her immediate family members has a history of this disease," she said. M.D. Ray, Additional Professor, Surgical Oncology, at All India Institute of Medical Sciences (AIIMS), also said that breast cancer can be inherited if a woman has a close family member who had developed the disease.
However, the family history is majorly defined by genetic mutations in a specific set of genes found augmenting the disease occurrence. The Nanavati Super Speciality Hospital in Mumbai informed that the risk of breast cancer is over 80 per cent higher in those who inherit a specific set of mutated genes BRCA1 and BRCA2
"The most common genes changes are those of the BRCA1 and BRCA2 genes and women with these genes have more than 80 per cent chance of getting breast cancer during their lifetime," said Sanjay Dudhat, Head Oncosurgeon at the hospital.
BRCA1 (BReast CAncer gene 1) and BRCA2 (BReast CAncer gene 2) are genes that produce proteins that help repair damaged DNA. Everyone has two copies of each of these genes one copy inherited from each parent. However, when these genes undergo certain harmful changes, their variant becomes potent enough to cause cancer cells. People who inherit harmful variants in one of these genes have increased risks of several cancers most notably breast and ovarian cancer. People who have inherited a harmful variant in BRCA1 and BRCA2 also tend to develop cancer at younger ages than people who do not have such a variant.
The Indraprastha Apollo Hospital in Delhi said that inherited mutated genes is a risk factor of breast cancer that one cannot change. "BRCA 1 and BRCA 2 are hereditary genes that if passed from the mother (who has suffered from breast cancer) to the children can put them at a higher risk of developing breast cancer and ovarian cancer," said Ramesh Sarin, Senior Consultant, Surgical Oncology at Apollo.
However, he added that screening and genetic counselling can help in early identification for the timely treatment of the disease. "Issue with any kind of cancer is that it never shows symptoms in early stages. While there are no sure shot ways to prevent cancer, certain steps can help lower the risk or detect breast cancer at an early stage," Sarin said. The experts recommended screening with several tests including mammography, specialised monitoring and BRCA gene test to have an upper hand over the disease.
"The BRCA gene test is a blood test that uses DNA analysis to identify harmful mutations in either one of the two breast cancer susceptibility genes. It is not a routine test and is done only on people who are likely to have inherited either of the BRCA genes based on family history of breast and ovarian cancer," Sarin recommended.
Dudhat advised to find out high risk individuals through genetic counselling and keeping them under proper screening programmes with regular mammography and in selected cases, MRI mammography.
Sarin said that mammography in young girls is not recommended. However, he suggested that the family should be aware of the risk and also stays in constant touch with a breast physician for regular monitoring.
Meanwhile, Shukla advised that annual screening is must for females above 40 years of age including mammography and x-ray of chest area. "However, females in families having a history of breast cancer must be vigilant. We prescribe screening of them from the age of 25 onwards" she added.