There is better awareness about genetic testing for cancer in the city. Within a month of its launch, the first counselling centre set up in a city hospital to advise people on whether or not they need to take genetic tests has seen eight families with a strong family history of cancer walk in for consultations, to figure if they are predisposed to the condition. In three cases, genetic tests were advised to assess their risk.
Health experts note that people are gradually becoming better informed, even prepared to deal with an illness that in most cases continues to catch many unawares. Besides, with multiple firms offering genetic tests, the centre comes in handy to figure out whether an individual really needs to undergo the test at all. There are strict guidelines for performing such tests, including family history (cancer in two or more relatives and their age when it was detected). Moreover, doctors say that all such predictive testing has to be preceded and followed by appropriate genetic counselling.
"Till date, 8 families have been referred to us, of which three needed genetic testing. Most people are anxious after they see their mother or sister die of cancer," said consultant molecular pathologist Aditi Dastane, who works with the molecular diagnostic laboratory at Deenanath Mangeshkar Hospital and Research Center where the cancer genetics centre became operational from January 1.
Among those who approached the centre was a family that had seen three deaths due to breast and ovarian cancer. One aunt in the family was a breast cancer survivor. The man from the family who approached the counselling centre was the father of a 28-year-old who was suffering from breast cancer and wanted to know the risk for his other two daughters. Besides, he had seen his wife go through 17 chemotherapies and wanted to take all precautionary measures to protect his daughters.
"In this case, as a preventive strategy, we recommended the affected person to get genetically tested first and if the test came positive, the same mutation can be checked in the at-risk sisters. If negative, then they should undergo routine mammography or sonography every year, starting 5 years before the cancer was diagnosed (in their sister) and continue till 5 years later," Dastane said.
Doctors say patients’ families find relief that they have somebody to hear them out collectively and see the complete picture, as most oncologists do not go beyond basic patient care. "Even if they do, the results of these genetic tests are very complicated and cannot be interpreted easily," Dastane said.
The American Cancer Society mandates that genetic tests be preceded and followed up by pre-test and posttest counselling sessions. "We help them take an informed action about their care because the ultimate decision lies with the individual," she added.
Genetic tests were expensive till a couple of years ago and were based on knowledge gained through the research mainly on Caucasian or rarely Asian (Chinese) population. "However, now even newer methodology of sequencing called next-generation sequencing (NGS) is indigenously being performed here in India. This technology, apart from sequencing the whole gene, has the power to detect new mutations in the Indian genes, which were unknown till now," Dastane said.
Mutation studies will change the way cancer is treated. Molecular biologist and counsellor Vaijayanti Pethe said, "As we learn more and more about India specific mutations, we can offer personalised treatment to these families and their future generations. Also, the new cancer genetic tests are offered at affordable cost to the patient."
Citing an example, Pethe said, "We recently came across a farmer who had two sons, aged nine and seven years and suffering from familial adenomatous polyposis (FAP). These patients had 100 to 1000 polyps in their colon and are prone to develop colon cancer at a very young age. Both had their colectomies done and now he wants to get his third son tested. If he hasn’t inherited this autosomal dominant trait, he need not be put through the trauma of colonoscopies every year. If he has, then they can opt for a partial colectomy before he develops those polyps."
But it’s important to do the tests only if the probability (for cancer) is high. "A negative test does not mean a negative result and a positive test does not mean a death knell," said medical oncologist Minish Jain of Ruby Hall’s Cancer Centre. "It’s important to interpret the tests correctly and advise patients to change their daily lives accordingly," he added.Source
Times of India
04 Feb 2014,
by - Umesh Isalkar