WHOEVER says Hong Kong people are indifferent should take a closer look at what the ''kings and queens'' of music are doing. Andy Lau Tak-wah, Jacky Cheung Hok-yau, Faye Wong Ching-man and Sally Yeh Chen-ven hope to educate the Hong Kong public about cancer in the ''Queen Mary Charity Concert'', to be held next month. Their message: cancer is not necessarily a terminal disease - it can sometimes be cured with the appropriate medication and care. On September 17 at Hong Kong Coliseum, the stars will perform to raise funds for the expansion of the Queen Mary Hospital Cancer Centre, which has been treating cancer patients for several decades. ''The reason for donating money to the centre instead of to other medical centres is that cancer is still the number one killer disease in Hong Kong,'' Queen Mary Hospital chief executive Dr Vivian Wong said. ''The funds will be used to promote cancer education, which involves informing the public about the symptoms of cancer and encouraging locals to check up with their physician regularly. Early diagnosis is very crucial since it allows treatment to start as soon as possible,'' she said. The hospital's Dr Chiu Kin-wah says awareness of the disease is still inadequate among the young. ''The most urgent message for Hong Kong's youth is: do not smoke. They may think it is not for young people to worry about cancer, but the fact is that if you smoke, you are putting your life at stake.'' Hospice care is another vital reason for the centre's expansion. For cancer patients battling to come to terms with their illness, such personal care can revive their will to live - an essential element in the fight against the disease. ''If patients have professional social workers to turn to, their lives would not be that desperate,'' Dr Chiu said. ''The first thing that comes to patients' minds is that treatment is painful and tedious. But with counselling and consolation, patients can get through it with the pain lessened.'' Psychological care will be complemented by hi-tech medical equipment. The funds raised by the concert will be used to install new radioactive equipment and improve surgical techniques. Meanwhile, the singers are upbeat about the concert. Cheung said: ''I believe our participation will attract more attention from Hong Kong citizens and this is the best I can do to help.'' Lau feels the same way. ''For us, being here is to signify the importance of the message and perhaps it is what the public needs.'' And that is exactly what cancer patients need.