The Hospital Authority has enacted the Drug Formulary in 2005. Since then public hospital patients are required to acquire unlisted formularies at their own expense.

Cancer has been the No. 1 killer disease among all. Lung and Colon Cancers seldom have visible signs and symptoms, which reduce the chance of early discovery. As a result, they are usually found in late stages when ordinary treatments have little to achieve. Doctors will have no choice but to recommend new drugs which does not have any subsidy.

Tuen Mun Hospital's recent figures indicated an average of 2,000 new cancer cases were discovered each year. 800 of them required medication of which 100 patients needed financial aid. Other source of finding confirms Tuen Mun Hospital's patients are the least financial capable among all districts. 

Regarding for a lot of underprivileged cancer patients need help, Mr Yam Tak- cheung, MH, therefore proposed to set up a fund to assist the needy. Thanks to the major initial contributions made by the fund's namer Ms Shirley Chong Sok-un, MH, and Dr Chan Kwok-chiu, BBS, MH, JP, and donations accorded from members of the Yan Oi Tong Board of Directors, Advisory Board and the public, over ten million dollars were collected shortly. Without their prompt responds, the Fund might not be established in such a fast pace. 

Since the Fund has specialized service scope, in order to integrate all walk-of-life activities related to fund raising, investment and application vetting, the YOT Chong Sok Un Medical Fund (cancer aid) Company Limited was incorporated and registered as a non-profit organization on April 9, 2008.