HONG Kong's first bone marrow transplant unit to specialise in treating solid tumours such as breast and ovarian cancers opened this weekend at the Matilda Hospital. The unit, which is also Hong Kong's first such private centre, will treat patients with common cancers who need such a huge dose of chemotherapy that would normally kill the bone marrow - and the patient. The unit will use the latest in bone marrow transplant technology, according to spokesman Dr Bernard Chan Wan-dun. Staff will give patients the huge doses of chemotherapy they need - up to 10 times the normal amount - but only after removing their bone marrow. Then the bone marrow will be re-infused into the patient to ''rescue'' them. The treatment - known as an autologous transplant - is normally used for leukaemia and blood disease patients where a donor with matching bone marrow cannot be found. The unit will also provide transplants using donated marrow if necessary. Although bone marrow transplants can be performed in private hospitals in Hong Kong, Dr Leung Wang-kit, an attending physician attached to the unit, said he believed the Matilda was the first to set up a dedicated unit, and to aim to treat patients with solid tumours. The unit, which cost $14 million to build and equip, is also believed to be the first in the territory to involve a collaboration between a private and a public hospital. The Matilda has agreed to treat between 10 and 24 Prince of Wales Hospital patients over the next two years at minimal cost, charging only for drugs and nursing care. The final number will depend on the amount of funding the Matilda can raise to cover these costs. For paying patients, however, the treatment will not come cheap. An autologous transplant will cost between $250,000 and $300,000, while transplants using donated marrow will be about $800,000, because they are much more complicated. Despite these prices, Dr Leung said the hospital was confident the unit would be in great demand. ''There is always a limitation as to the capability of existing units,'' he said, adding that one source of patients could be those considered too old for a transplant in a public hospital. In many instances, he said, there was an age limit of 45 or 50 years for bone marrow transplant patients. ''If you are 51, your life is dispensable,'' he said. Dr Chan agreed there would be great demand, saying that the bone marrow unit at Queen Mary specialised in treating blood cancers while that at Prince of Wales was only for children.