World Cancer Day: How genetic counselling plays a major role in early detection of cancer
On World Cancer Day, we explore the role that genes play in detection of cancer and determining who gets afflicted by the disease.Updated: Feb 04, 2018 11:13 IST
It is important to keep in mind that up to 10% of cancer cases have a hereditary component. This essentially means that despite healthy lifestyle habits, if we have inherited a bad copy of a gene that plays a role in cell renewal, we are always at a greater risk of developing cancer.
Two of the best-known such genes are BRCA1 and BRCA2, which infer a significantly increased risk of getting breast and ovarian cancer if a mutation is present in either of these genes. Scientific and medical research shows that there are several other genes that may cause cancer in a similar manner.
Some gene mutations are responsible for specific cancer types, while others are involved in many types of cancers, complicating the cause and effect scenario significantly. It requires experts in genetics and cancer to shed light on what causes cancer and choosing the right treatment.
Genetic counsellors are trained to understand a patient’s family history of illnesses, including cancers, and draw up scientifically valid “pedigree charts” (or a family tree) to map a disease across up to three generations or more. This specialised training uniquely qualifies them to understand a person’s family history of a disease like cancer. They are skilled at interpreting this knowledge and can provide accurate predictions of the risks faced by a person who makes use of their services.
Additionally, genetic counsellors can explain the consequences of inheriting bad cancer genes to patients, family members, as well as doctors. Hence, genetic counsellors fill this important information gap by explaining the importance of genetics to families and working with doctors to get the best diagnosis and treatment for patients.
Today, genetic counsellors use their training and experience along with highly sophisticated prediction software to interpret a person’s family history. Using this information, they can determine whether a person is at a higher risk of developing cancer in his or her lifetime compared to the average cancer risk of about 1-2% for most cancer types. Once the genetic counsellor is certain that there is a significantly higher risk, he can recommend the appropriate genetic tests.
These tests can identify whether a disease-causing gene mutation is present in a person’s DNA or not and allow a genetic counsellor to calculate a person’s risk for getting cancer even more accurately.
Inputs from Dr Nitesh Rohatgi, Principal Consultant, Medical Oncology, Max Cancer Center; Dr. Sudhir Borgonha is Chief Medical Officer, Strand Life Sciences.
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