01 Mar 2011
Many of us are likely to hold an established view on organ donation. But how many have thought of a much more fundamental “body part” that is available for donation – bits of tissue cut out during surgery?
Consider a fictional character Mdm Foo, a housewife in her mid-50s, who noticed a hard lump in her left breast. As her aunt had died of breast cancer, she saw her doctor immediately. After undergoing a biopsy, her doctor confirmed she had breast cancer and needed surgery to remove the affected part. During her preoperative tests, a member of the hospital’s tissue bank talked to her about tissue donation and asked whether she would donate some of the tissue – about to be cut out – to research.
But what is tissue donation all about?
DNA and the appreciation of tissue With the mapping of the human genome completed in 2003, scientists now have the tools to discover what causes cells to become cancerous, how to recognise them early and come up with more targeted treatments. This research requires tissue material.
Following surgery, the tumour is examined by a pathologist to determine what type of cancer it is, how far it has spread and how aggressive it is likely to be. This information enables the doctor to make a diagnosis and determine the best treatment for the patient.
The leftover tumour tissue (which is valuable to scientists) is normally discarded, meaning a precious resource that may lead to breakthroughs in cancer diagnosis and treatment ends up in the bin.
Let’s return to our example. With the information from the pathologist, Mdm Foo’s surgeon was able to confirm that her cancer was aggressive and would best respond to a specific treatment, which she then started on. But this still leaves quite a few questions unanswered:
Why did she develop the cancer? Are her children likely to get it too? And could it have been discovered earlier, helping her avoid surgery?
Extensive research on tumour tissue has provided some answers. So instead of wasting the leftover tissue, patients can donate them to research.
Tumour tissue contains the blue print of a disease, telling researchers what genetic changes it has gone through.
Sometimes, researchers can identify a unique change that can be used as a marker of early disease or as a target for new treatments.
Naturally, this research cannot be done overnight or by examining just one individual’s tissue material.
Investing it right
Tissue banks approach patients, like Mdm Foo, to seek their consent to donate any leftover tissue. But patients may have some concerns: Will I have to undergo another operation? Will research take precedence over my own needs? And will my personal information be kept confidential?
Only when the tissue is no longer needed, meaning after information necessary for diagnosis and treatment has been extracted, is the tissue banked for research. The donor will not have to go for another procedure.
His identity will also not be disclosed as the source of tissue will be anonymous.
The donated tissue is preserved in liquid nitrogen, at temperatures as low as -196°C. This is to ensure researchers can view an exact snapshot of a disease at a particular time.
But if she were to donate her tissue, what guarantee does Mdm Foo have that it will be used appropriately?
Much like a conventional bank that has been entrusted to invest people’s savings, tissue banks are also prudent about the use of this resource. Access is only granted to studies approved by an institutional review board which safe guards the interests of the community at large and ensures the research meets ethical standards.
There is also an oversight committee (composed of senior doctors and scientists) that vets every request for tissue, to ensure donations are used in the spirit that they were donated and lead to new knowledge, benefiting future generations. Banking on a brighter future We are slowly but surely moving away from the “one size fits most” model of medicine to a personalised approach based on an individual’s genetic blueprint.
With this, the role of tissue is placed centre stage.
According to Time magazine, tissue banks, also known as biobanks, are among the 10 ideas that are changing the world.
For a small nation like Singapore, tissue quantity and variety pose certain challenges. Our patient pool is small and some conditions may only be present in one or two individuals per year. For example, the SingHealth Tissue Repository only has one malignant eye tumour sample available out of its repository of some 10,000 pieces of tissue, collected over the last 14 years. In contrast, available breast tumour tissue samples number close to 2,000.
But if we can collect sufficient tissue, researchers can identify specific genes that trigger a condition, which means better screening, earlier diagnosis and more effective treatment.
But before we hype up the potential of tissue research, we need to think what we would do if we were in Mdm Foo’s shoes.
Only if we choose to donate our leftover tissue can the full potential of this relatively young field be realised.
Click here for jpeg format
« Back to previous
page
back to top