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The actual take-up rate among patients here who had been counselled for genetic cancer testing was low compared with the initial high level of interest, a study has found.
These patients were evaluated in a cancer genetics programme at the National University Cancer Institute, Singapore (NCIS).
The study, published last year in the American journal Genetic Testing And Molecular Biomarkers, found cost to be one of the main barriers against testing.
Other concerns included the negative implications of test results on the individual and family, and the belief that genetic information cannot change medical management.
Health programmes that address cost issues and provide targeted education may help allay fears and correct misperceptions, and encourage more people at risk of having genetic mutations to be tested, said Dr Lee Soo Chin, a senior consultant oncologist at NCIS, the principal investigator of the study.
Based on the genetic information, doctors can better tailor recommendations on managing the risk of cancer for each individual, she explained.
Very few studies have been published on the acceptance and uptake of cancer genetic testing in Asians in the actual clinical setting, she said.
In her study, 317 patients, who were of at least modest risk of having a hereditary predisposition for cancer, were routinely given a structured questionnaire between August 2003 and July 2010.
It evaluated their attitudes and perceived motivators and barriers immediately after genetic counselling.
Most patients expressed an interest in genetic testing, felt generally positive with the information, and cited three-fold more motivators than barriers towards testing.
Many patients perceived no barrier to testing initially.
However, only 35 per cent of cancer-affected patients, called index patients, were eventually tested, suggesting that more barriers existed in reality than could be immediately appreciated by the patients, said Dr Lee.
Cost a factor
In Singapore, the test cost is fully borne by the patient and is substantial relative to the median household income, which was about $5,051 at the time the study was done.
Test costs, up to a month ago, ranged between $2,500 and $3,000.
It now costs between $1,500 and $2,500 as the tests are being sent to a different laboratory.
A previous study by Dr Lee, published in 2006, found that more people went for testing of genes related to breast and ovarian cancer, BRCA 1 and 2, when the cost was reimbursed by a government grant.
The uptake rate for such tests grew 11-fold from 4 per cent before 2004, to 44per cent between 2004 and 2006.
After the government grant programme was discontinued in 2006, the rate dropped to 23 per cent.
In the current study, slightly more than half the decliners cited cost as the barrier.
Of the 69 index patients who underwent BRCA 1 or 2 testing in this study, more than half were tested as part of the government grant programme, said Dr Lee.
This highlights that health programmes which reimburse test cost in moderate- to high-risk individuals may encourage more to go for testing.
A goal would be to identify mutation carriers early on and recommend regular screening and preventive programmes.
A study by the National Cancer Centre Singapore and Singapore General Hospital showed that screening-detected cancer was smaller, had not spread to the lymph nodes and required less treatment, which means less cost to the patient.
Other hurdles
But other existing barriers may still preclude genetic testing even when the cost barrier is overcome.
For example, when clinical BRCA 1 and 2 genetic testing was briefly offered free in Singapore, more than 50 per cent of moderate-risk index patients - those who had cancer and were at moderate risk of having a defective gene - still declined testing.
Similarly, another study reported that African-American women were less likely than Caucasian women to take up BRCA genetic testing even when the cost barrier was minimised, suggesting that ethnic or culturally related barriers may exist.
In Dr Lee's latest study, more than 40per cent of decliners cited barriers other than costs.
In Asia, cancer remains a taboo subject, and patients carrying a genetic mutation that predisposes them to cancer may fear social stigmatisation, she said.
Also, 16 per cent and 15 per cent of decliners, respectively, cited the fear of emotional burden and stress associated with genetic information on themselves and their family as the reasons against testing, and 11 per cent of decliners made a deliberate choice not to know the genetic information.
In another recent report, 83 per cent of Malaysian carriers of BRCA 1 or 2, who were detected through a research protocol, chose not to share their test results with family members as they did not want to burden them. Several carriers also faced familial pressure to conceal their genetic mutation from their future spouses.