GCF Chan

This issue is to celebrate the 28 years of establishment of the Hong Kong Paediatric Haematology & Oncology Study Group and also the commencement of Paediatric Oncology Service at the new Hong Kong Children's Hospital. All these are the results of selfless devotion and collaboration among the local paediatricians, no matter they have special interest in the field of paediatric haematology and oncology or not. It also involves the endless efforts and contributions of at least 4 generations of colleagues before we can arrive at what we stand today.

Since 1992, our seniors taking care of children with cancers from different hospitals worked together and formed the Hong Kong Paediatric Haematology & Oncology Study Group. The treatment protocols of common childhood cancers were then unified and shared. All the newly diagnosed cases were registered but that was a very laborious process. Subsequently, with the help of Children's Cancer Foundation, full time data managers were employed to manage the database and then we could prospectively capture the treatment outcome and complications of all patients under our care. Since then, we have the first and most comprehensive population based epidemiology data of Chinese children with cancers. It is updated yearly in our Annual Scientific Workshop.

However, the specialty development encountered a bottleneck because of the relatively low number of patients in each individual hospital. Again, with the help of many seniors, Government and Children's Cancer Foundation, the plan of establishing a long awaited Hong Kong Children's Hospital was finally approved. And we witnessed her commencement of operation just over the last few months. Now the patients can have better care under one location and paediatric trainees can maximise their exposure and learning. Most of the other paediatric subspecialties are gradually moving in and it will benefit all paediatric subspecialties eventually.

At this unique point of time, it is a good opportunity for us to review what we have done together. Our experience in managing both acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML) are summarised in this issue. We have witnessed the drastic improvement in the management of childhood leukaemia and most of the children with ALL can survive nowadays. Even for AML, some of the subgroups can achieve very good cure rate. Looking back, the major cause of improvement is not due to the introduction of new therapeutic agents but rather intelligent use of existing agents via carefully designed clinical trials. Most of these clinical trials were made possible only through international collaboration and we have been actively participating in this endeavor. Despite many skeptical comments initially, most of our patients' parents agreed to enroll their children to our randomised controlled trials. The philosophy behind is that the result generated can help us to improve our treatments and eventually achieve a much better strategy for children who suffer from leukaemia.

Haematopoietic stem cell transplantation (HSCT), targeted therapy and various forms of immunotherapy are all additional armamentarium that we acquired since 90's. For HSCT, we have already overcome the HLA barrier and can now utilise the half HLA-matched parents as donors. Therefore, no patient will be deprived of the choice of transplant due to lack of donor if his/her condition is really indicated. The evolution of small molecules targeted therapeutic agent such as imatinib and its derivatives also revolutionises our approach to chronic myeloid leukaemia and Philadelphia chromosome positive ALL. The availability of anti-CD20 monoclonal antibody, anti-CD3/anti-CD19 bispecific antibody, and even anti-CD19 chimeric antigen receptor (CAR) T cells further improves the survival of many previous incurable refractory or resistant leukaemic patients. The new challenge is how to cope with the escalating cost of all these newer forms of treatment.

With the improvement of survival, our other challenge is how to minimise the therapy related side effects of our young cancer survivors. The therapy related side effects can be either acute or chronic and it may affect different organ systems. Some can be evolved many years later; therefore long term follow up is essential. The endocrine, neurological, cardiac, renal and musculoskeletal are the frequent organs affected and they should be regularly monitored. Interestingly, obesity rather than failure to thrive is another common long term complication noted among cancer survivors. However, one also has to emphasize that not all the acute or chronic complications are really therapy related. For example, some neurological deficit or endocrine organ damage can be caused by disease process itself. For example, in brain tumours, the local invasion or increased intracranial pressure can lead to transient or permanent neurological damage. Tumours originated from the suprasellar region may lead to hypopituitarism and diabetes insipidus. Early detection may minimise the extent of damage of these organs.

In paediatrics, we often combine the haematology and oncology together as a subspecialty. On one hand, it is due to the rarity of these diseases. On the other hand, the most common form of childhood cancer is leukaemia which can be considered as a blood disease. Therefore, in this issue, we also share with our readers our experience on diagnosing and managing some interesting blood diseases. In fact, in the Children's Hospital, our service also covers most of the rare or complicated blood diseases. In 2 specific haematological disorders, namely haemophilia and thalassemia, they will receive routine care in their original regional hospitals but will be seen in a comprehensive clinic at the Children's Hospital around once or twice a year. Then patients from different regional hospitals can have standardised treatment approach and care.

Here, may I wish the Hong Kong Paediatric Haematology & Oncology Study Group and the Hong Kong Children's Hospital continue to grow and progress. We hope that the Study group and the Children's Hospital will reach a new horizon and in pars with other eminent study groups / children's hospitals in the world. This is the expectation of most of the health care providers and patients' families locally. If we keep our collaborative spirit, we have full confidence on our younger generation in achieving this goal!