DocTalk

The wonders of medical research

Acute leukaemia patients are getting a new lease of life, thanks to stem cell transplants

People who watch Korean and Taiwanese dramas might find this scenario familiar: The male or female lead gets a shock diagnosis of leukaemia and, shortly after, succumbs to the disease.

Many patients whom I see consider the blood cancer a death sentence when they are first diagnosed with it.

I suspect that this misconception is partially due to the bad "publicity" that this condition has garnered from such TV dramas.

In reality, there are several sub-types of leukaemia and all of them behave differently.

The chronic types, for example, are slow-growing.

A better understanding of the molecular structures of chronic leukaemias has led to effective treatments that target specific proteins that help tumours spread and grow.

ST ILLUSTRATION: ADAM LEE

This has prompted a paradigm shift over the last decade towards a "less is better" treatment strategy.

Treatment has thus shifted from chemotherapy to targeted drugs, and these leukaemia cases are now regarded in the same vein as diabetes and hypertension.

There is also a feeling of gratitude for the donors, who had the courage and selflessness to provide the "gift of life" to our patients.

I remember counselling one of my youngest patients, Ms P, and her family in 2006, when she was first diagnosed with chronic myeloid leukaemia. She was just 16 then.

Her family was expecting chemotherapy and transplantation, and could not believe that all it took was a couple of pills to keep her disease at bay.

A decade on, she remains well, with her disease in remission, and she is pursuing her dreams.

Every time Ms P and others like her step into my consultation room, I am inspired again by the wonders of medical research that have touched so many lives.

NOT EASY TO FIND A MATCH

Acute leukaemia, in contrast, is more aggressive and chemotherapy is the mainstay of treatment.

Unlike childhood leukaemia, where treatment outcomes are excellent, only about 30 to 40 per cent of adults with acute leukaemia are cured of it.

Today, doctors can do genetic risk stratification on cancer cells and identify patients who cannot be treated with only chemotherapy and who, therefore, require stem cell transplants.

Stem cell transplant involves eradicating unhealthy leukaemia cells and replacing them with healthy donated stem cells.

Such transplants carry risks - patients can get an infection or the donor cells can attack their bodies.

The search for suitable donors also remains arduous, especially for patients who do not have siblings who are compatible donors.

The odds of finding an unrelated donor match is one in 20,000 while siblings have a 25 per cent chance of being an exact match.

Fortunately, the work by the various worldwide registries, including Singapore's Bone Marrow Donor Programme, has helped to facilitate this process.

In recent years, the ability to conduct half-matched (haploidentical) or cord blood transplants has given more patients hope for a cure.

As transplant doctors, our difficulties lie in selecting patients who are most likely to benefit from a transplant.

In addition, collaboration between specialists in various disciplines is also needed to handle the complications of transplants.

When caring for patients afflicted with very serious diseases, we often have to accept that, despite our best efforts, we will not be able to cure all of them.

There is also a constant need to keep up with the latest research in order to identify new treatments that may help patients.

Despite these challenges, most of my medical and nursing colleagues would still choose this field again, if they were asked to make a choice.

Our programme, like most transplant programmes worldwide, holds annual celebrations for transplant donors and recipients.

While it is meant as a celebration of life for patients and their families, I find that it is also a time of reaffirmation for the medical, nursing and allied health team.

Watching former and new patients gather to share their experiences, and seeing patients with their spouses and kids, give the team a new-found appreciation of our job.

There is also a feeling of gratitude for the donors, who had the courage and selflessness to provide the "gift of life" to our patients.

I often wonder when Professor E. Donnall Thomas, the father of stem cell transplantation, first carried out his pioneering experiments in the field, whether he ever envisioned a future where more than 50,000 transplants are done yearly worldwide.

I suspect that this would have meant much more to him than the Nobel Prize he received in 1990 for his contributions in this field.

  • Dr Michelle Poon is a senior consultant at the Department of Haematology-Oncology, National University Cancer Institute, Singapore.
A version of this article appeared in the print edition of The Straits Times on January 17, 2017, with the headline 'The wonders of medical research'. Print Edition | Subscribe